Merge remote-tracking branch 'origin/main' into feature/046

.gitea/ISSUE_TEMPLATE.md

@@ -1,35 +0,0 @@
-## 背景
-
-なぜ必要か。
-
-## 対象範囲
-
-- backend:
-- frontend:
-- docs:
-- migration:
-
-## やること
-
-- [ ] 
-
-## 受け入れ条件
-
-- [ ] 
-
-## 実行すべき確認
-
-- [ ] `cd backend && bundle exec rspec`
-- [ ] `cd frontend && npm run build`
-- [ ] `cd frontend && npm run lint`
-
-## 禁止事項
-
-- unrelated refactor はしない
-- 既存 API response shape を壊さない
-- 認証・認可・BAN を弱めない
-
-## Codex への指示
-
-この issue を読んで実装してください。
-不明点があれば、実装前に調査結果と選択肢を提示してください。

backend/AGENTS.md

@@ -1,411 +0,0 @@
-# backend/AGENTS.md
-
-## Scope
-
-These rules apply to work under `backend/`.
-
-This is a Rails API app using Active Record, RSpec, request specs,
-service objects, representation classes, and version tables for post/tag/wiki
-history.
-
-## Commands
-
-Use commands backed by files and dependencies in this directory:
-
-```sh
-bin/setup
-bin/dev
-bin/rails
-bin/rake
-bin/rubocop
-bin/brakeman
-bundle exec rspec
-```
-
-Common checks:
-
-```sh
-bundle exec rspec
-bin/rubocop
-bin/brakeman
-```
-
-Common Rails commands:
-
-```sh
-bin/rails db:prepare
-bin/rails db:migrate
-bin/rails routes
-bin/rails server
-```
-
-After backend behavior changes, run the relevant RSpec files. For broad backend changes, run:
-
-```sh
-bundle exec rspec
-```
-
-If a command cannot be run or fails, report the exact command and failure.
-
-Do not create, modify, or run tests unless the user explicitly asks for test
-work. When the user asks for tests, keep working and rerun them until they
-pass or the remaining failure is clearly blocked.
-
-## Rails structure
-
-- `app/controllers`: API controllers.
-- `app/models`: Active Record models and concerns.
-- `app/representations`: JSON response shaping.
-- `app/services`: domain services such as version recorders, wiki commit,
-  YouTube sync, and similarity calculation.
-- `config/routes.rb`: public API routes.
-- `db/migrate`: migrations.
-- `db/schema.rb`: schema snapshot.
-- `lib/tasks`: custom Rake tasks.
-- `spec`: RSpec tests.
-
-Before changing behavior, inspect the matching route, controller, model,
-service, representation, and spec.
-
-## Shared backend systems
-
-Before adding backend behaviour, search the existing backend first. At minimum,
-check these locations:
-
-- `app/controllers`
-- `app/controllers/concerns`
-- `app/models`
-- `app/models/concerns`
-- `app/representations`
-- `app/services`
-- `app/services/*`
-- `app/jobs`
-- `lib`
-- `lib/tasks`
-- `config/initializers`
-
-Do not infer commonality from directory names alone. Read the actual
-responsibility and representative usage sites.
-
-### Controller reuse
-
-Before adding logic to a controller, inspect:
-
-- `ApplicationController` authentication, authorization, BAN, and IP BAN
-- existing render and validation-error helpers
-- existing param parsing
-- controller concerns
-- the controller for the same resource
-- existing services
-- existing representations
-
-Keep controllers focused on:
-
-- authentication and authorization
-- parameter intake
-- service and model invocation
-- HTTP status selection
-- representation selection
-
-Do not reimplement these per controller when an existing path already owns
-them:
-
-- authentication and role checks
-- validation error JSON
-- URL normalisation
-- tag normalisation
-- thumbnail handling
-- version recording
-- complex transactions
-- external HTTP fetching
-- response representation assembly
-
-### Authentication, authorization, and BAN
-
-Treat these as the canonical backend entrypoints:
-
-- `ApplicationController#authenticate_user`
-- `current_user`
-- `X-Transfer-Code`
-- `reject_banned_ip_address!`
-- `reject_banned_user!`
-- `gte_member?`
-- `admin?`
-
-Do not create feature-local permission services, role comparisons, or header
-parsing when the existing authentication boundary already owns the behaviour.
-If the current boundary is insufficient, extend it minimally instead of adding
-another permission path.
-
-### Representations
-
-If an endpoint for the same resource already uses `app/representations`, do not
-assemble a separate JSON shape directly inside the controller without first
-checking the existing representation contract.
-
-Inspect at least:
-
-- `PostRepr`
-- `TagRepr`
-- `MaterialRepr`
-- `TheatreRepr`
-- `UserRepr`
-- `WikiPageRepr`
-- `DeerjikistRepr`
-
-When a lightweight response is genuinely different in purpose, keep it
-deliberate and compatible with the surrounding contracts. Do not force every
-identifier list into a large representation, but do not fork the same resource
-shape casually either.
-
-### Domain services
-
-When work touches multiple models, transactions, external APIs, file handling,
-history creation, or multi-step workflow, search `app/services` first.
-
-At minimum, search for existing services in these responsibility areas:
-
-- version recorder and versioning
-- wiki commit
-- YouTube or Google Drive API client
-- material sync or ZIP export
-- similarity calculation
-- theatre selection or skip finalisation
-- metadata, thumbnail, or file processing
-- URL normaliser or sanitisation
-- import or export
-- preview safety or HTTP fetch
-
-Do not create a same-responsibility service under another namespace or another
-name. If an existing service is close, extend that API minimally instead of
-wrapping it in a feature-local service.
-
-### Versioning
-
-When a feature writes history, snapshots, or restore roots, search the existing
-versioning path first. At minimum, inspect:
-
-- `VersionRecorder`
-- `PostVersionRecorder`
-- `TagVersionRecorder`
-- `TagVersioning`
-- `MaterialVersionRecorder`
-- `NicoTagVersionRecorder`
-- `WikiVersionRecorder`
-
-Do not implement history writes in controllers, callbacks, or ad hoc feature
-services when the recorder layer already owns the transaction boundary and
-meaning.
-
-### Normalisation, sanitisation, and parsing
-
-For URLs, tag names, times, video durations, identifiers, and paths, search the
-existing normaliser, sanitisation rule, parser, and model-callback path first.
-
-Do not let frontend, controller, service, and model each invent different rules
-for the same value. Use one canonical normalisation path and keep input
-validation distinct from pre-persistence normalisation.
-
-### External HTTP and URL safety
-
-When fetching external URLs, reuse the existing preview-safety stack. Search at
-least for:
-
-- URL safety
-- redirect validation
-- response size limits
-- timeouts
-- network failure mapping
-- HTML metadata extraction
-- known-site extraction
-- thumbnail fetching
-
-Do not add direct `Net::HTTP`, `Faraday`, or equivalent feature-local HTTP code
-that reimplements SSRF checks, redirect restrictions, size limits, or timeouts.
-If the current fetcher is insufficient, extend its existing safety contract.
-
-### Storage, files, and Active Storage
-
-When handling files, thumbnails, ZIP output, object storage, or Active Storage
-blobs, inspect existing storage helpers, exporters, thumbnail generators, and
-checksum helpers first. Do not reimplement the same attach, export path,
-download, resize, or checksum flow in a controller or one-off service.
-
-### Concerns
-
-Do not create controller or model concerns merely because some code is shared.
-Use a concern only when multiple classes share the same lifecycle, macro,
-callback, or tightly cohesive behaviour. Utility collections belong in explicit
-objects or services, not in `CommonConcern`, `SharedMethods`, or `Utils`.
-
-### Model boundaries
-
-Model-specific invariants, associations, validations, and normalisation may
-live in the model. Multi-model workflow, external access, complex transaction
-flow, and feature orchestration belong in services. Do not hide feature
-workflow in model callbacks.
-
-### Transactions, locking, and race handling
-
-If transactions, locking, idempotency, or race recovery already exist in a
-service or model method, do not add a second implementation in a controller or
-new service. Inspect the existing transaction boundary first, avoid wrapping
-the same operation in needless nested transactions, and handle unique-constraint
-races according to the target constraint's business meaning.
-
-## Ruby style
-
-- Prefer precise, minimal changes.
-- Use single quotes unless interpolation or escaping makes double quotes better.
-- Do not put a space before Ruby method-call parentheses.
-- For `render`-family method calls, omit parentheses even when passing
-  keyword arguments.
-- Never put a line break immediately before `)` in Ruby.
-- Do not use `%w` or `%i` in new Ruby code.
-- Never write a Ruby line longer than 99 characters.
-- Aim to keep Ruby lines within 79 characters where practical.
-- For small Ruby method definitions that take keyword arguments, match the
-  local no-parentheses style when nearby code uses it.
-- When an `if` condition is split across multiple lines and combines clauses
-  with `&&` or `||`, wrap the whole condition in parentheses.
-- Treat Ruby hash `{ ... }` style and Ruby block `{ ... }` style as separate
-  rules.
-- Do not format Ruby hashes like Ruby blocks.
-- For Ruby hashes, keep the closing `}` on the same line as the final pair.
-- Keep the first pair on the same line as `{` by default.
-- Short Ruby hashes may stay visually compact across two lines with the first
-  pair kept on the opening line and aligned continuation pairs below it.
-- If the hash would exceed the line limit, break after `{` and indent pairs
-  by 4 spaces.
-- Put one logical pair per line when the expression would otherwise become
-  dense.
-- For Ruby arrays, never put whitespace or a line break immediately before `]`.
-- Keep the first element on the same line as `[` by default.
-- If an array would exceed the line limit, break after `[` and indent
-  elements by 4 spaces.
-- For Ruby blocks, use 2-space indentation for the block body.
-- Keep comments short and useful; avoid narrating obvious code.
-- Do not add production dependencies without approval.
-
-## Authentication and authorization
-
-- Authentication is handled through the `X-Transfer-Code` header in
-  `ApplicationController#authenticate_user`.
-- `current_user` is set by looking up `User.inheritance_code`.
-- Do not bypass or weaken the `X-Transfer-Code` flow unless the task
-  explicitly changes authentication.
-- Unauthenticated write actions should return `:unauthorized` consistently
-  with existing controllers.
-- Role checks use `User` enum roles: `guest`, `member`, and `admin`.
-- Use `current_user.gte_member?` for member-or-admin write permissions where
-  existing controllers do so.
-- Use `current_user.admin?` only for admin-only paths, such as tag child relationship changes.
-- Do not replace role checks with looser presence checks.
-
-## BAN and IP BAN
-
-- `ApplicationController` runs these before actions in order:
-  - `reject_banned_ip_address!`
-  - `authenticate_user`
-  - `reject_banned_user!`
-- User and IP bans use `banned_at`, not a boolean `banned` column.
-- `User#banned?` and `IpAddress#banned?` check `banned_at.present?`.
-- Do not weaken BAN or IP BAN behavior.
-- If changing request authentication or controller before actions, add or
-  update request specs covering banned users and banned IP addresses only when
-  the user explicitly asks for tests.
-
-## RSpec
-
-- Prefer RSpec for new backend tests.
-- Put API behavior coverage under `spec/requests`.
-- Put model behavior under `spec/models`.
-- Put service behavior under `spec/services`.
-- Put Rake task coverage under `spec/tasks`.
-- `spec/rails_helper.rb` loads `spec/support/**/*.rb`.
-- Request specs include `AuthHelper` and `JsonHelper`.
-- `AuthHelper#sign_in_as(user)` stubs
-  `ApplicationController#current_user`; use it when matching existing
-  request spec style.
-- Add or update request specs for API behavior changes only when the user
-  explicitly asks for tests, especially status codes, permissions, response
-  shape, and version conflict behavior.
-
-## Migrations
-
-- Keep migrations and `db/schema.rb` consistent.
-- Use reversible migrations where practical; otherwise define explicit `up` and `down`.
-- For data backfills inside migrations, follow the existing pattern of
-  defining migration-local `ActiveRecord::Base` classes with
-  `self.table_name`.
-- Preserve existing indexes, foreign keys, check constraints, and null constraints.
-- Be careful with MySQL-specific options already present in migrations, such as `after:`.
-- Do not edit old migrations just to change current behavior unless
-  explicitly requested; add a new migration.
-
-## Version tables
-
-- Versioned records include posts, tags, nico tags, and wiki pages.
-- Current records have `version_no`; version tables have positive
-  `version_no` with unique indexes scoped to the parent record.
-- Version event types are `create`, `update`, `discard`, and `restore`.
-- Version rows are readonly through the `VersionRecord` concern.
-- Use the existing recorder services instead of manually inserting version
-  rows in application code:
-  - `PostVersionRecorder`
-  - `TagVersionRecorder`
-  - `NicoTagVersionRecorder`
-  - `WikiVersionRecorder`
-  - `TagVersioning`
-- `VersionRecorder` locks the current record, validates sequence consistency,
-  skips unchanged update snapshots, creates the next version row, and updates
-  the record `version_no`.
-- Do not update versioned records without considering whether a version snapshot must be created.
-- For optimistic concurrency paths, preserve `base_version_no`, `force`, and
-  `merge` semantics. Cover conflicts in request specs only when the user
-  explicitly asks for tests.
-
-## Domain cautions
-
-- Posts have tag snapshots, parent post implications, original-created ranges,
-  viewed state, and version conflict behavior.
-- Tags have canonical names, aliases through `TagName`, categories, parent
-  implications, discard behavior, and version snapshots.
-- Nico tags have separate relation/version behavior; do not treat them like
-  normal editable tags without checking existing code.
-- Wiki pages involve page content, revisions/history, version rows,
-  title/tag-name behavior, and diff/restore paths.
-- Materials, theatres, and comments have user and permission checks; inspect
-  the controller before changing them.
-
-## API responses
-
-- Use representation classes under `app/representations` when existing endpoints do.
-- Keep response keys consistent with existing JSON contracts.
-- Frontend code expects camelCase conversion client-side, while Rails params
-  and JSON keys are generally snake_case.
-- Preserve existing HTTP status conventions:
-  `:unauthorized` for no user, `:forbidden` for insufficient role or banned
-  user, `:not_found` for missing records, and `:unprocessable_entity` for
-  validation failures.
-- For diagnostic or internal helper JSON, prefer a deliberately light response
-  shape over full representation classes when callers only need identifiers,
-  labels, URLs, or weights.
-
-## Active Record performance
-
-- When a controller action serializes nested associations, preload the
-  associations it will touch instead of allowing N+1 queries.
-- Be sensitive to N+1 queries in all backend work.
-- Avoid introducing N+1 queries, and proactively fix existing N+1 issues when
-  you find them in the code path you are editing.
-- When an association may already be preloaded, prefer loaded-association
-  checks that reuse the preloaded data without losing the efficient database
-  path.
-
-## Files to avoid in routine work
-
-- Do not inspect or edit `tmp/`, `log/`, `storage/`, `vendor/`, or dependency
-  directories unless explicitly needed.
-- Do not modify generated schema or migration output without the corresponding
-  migration when schema changes are made.

backend/Gemfile

@@ -69,5 +69,3 @@ gem 'discard'
 gem "rspec-rails", "~> 8.0", :groups => [:development, :test]
 
 gem 'aws-sdk-s3', require: false
-
-gem 'rails-i18n', '~> 8.0.0'

backend/Gemfile.lock

@@ -306,9 +306,6 @@ GEM
     rails-html-sanitizer (1.6.2)
       loofah (~> 2.21)
       nokogiri (>= 1.15.7, != 1.16.7, != 1.16.6, != 1.16.5, != 1.16.4, != 1.16.3, != 1.16.2, != 1.16.1, != 1.16.0.rc1, != 1.16.0)
-    rails-i18n (8.0.2)
-      i18n (>= 0.7, < 2)
-      railties (>= 8.0.0, < 9)
     railties (8.0.2)
       actionpack (= 8.0.2)
       activesupport (= 8.0.2)
@@ -480,7 +477,6 @@ DEPENDENCIES
   puma (>= 5.0)
   rack-cors
   rails (~> 8.0.2)
-  rails-i18n (~> 8.0.0)
   rspec-rails (~> 8.0)
   rubocop-rails-omakase
   sprockets-rails

backend/app/controllers/application_controller.rb

@@ -1,19 +1,14 @@
 class ApplicationController < ActionController::API
-  rescue_from ActiveRecord::RecordInvalid, with: :render_record_invalid
-  rescue_from ActiveRecord::RecordNotUnique, with: :render_record_not_unique
-
-  before_action :reject_banned_ip_address!
   before_action :authenticate_user
-  before_action :reject_banned_user!
 
-  def current_user = @current_user
+  def current_user
+    @current_user
+  end
 
   private
 
   def authenticate_user
     code = request.headers['X-Transfer-Code'] || request.headers['HTTP_X_TRANSFER_CODE']
-    return if code.blank?
-
     @current_user = User.find_by(inheritance_code: code)
   end
 
@@ -27,62 +22,4 @@ class ApplicationController < ActionController::API
       s.in?(['', '1', 'true', 'on', 'yes'])
     end
   end
-
-  def render_bad_request message = 'リクエストが不正です．'
-    render json: { type: 'bad_request',
-                   message:,
-                   errors: { },
-                   base_errors: [message] },
-           status: :bad_request
-  end
-
-  def render_unprocessable_entity message = '入力を確認してください．', field: nil
-    render_validation_error(fields: field ? { field => [message] } : { },
-                            base: field ? [] : [message])
-  end
-
-  def render_record_invalid error
-    render_validation_error error.record
-  end
-
-  def render_record_not_unique _error = nil
-    render_validation_error base: ['すでに存在してゐます．']
-  end
-
-  def reject_banned_ip_address!
-    ip_address = IpAddress.find_by(ip_address: IPAddr.new(request.remote_ip).hton)
-    return unless ip_address&.banned?
-
-    head :forbidden
-  end
-
-  def reject_banned_user!
-    return unless current_user&.banned?
-
-    head :forbidden
-  end
-
-  def render_validation_error record = nil, fields: { }, base: [], status: :unprocessable_entity
-    errors = { }
-
-    if record
-      record.errors.each do |error|
-        errors[error.attribute] ||= []
-        errors[error.attribute] << error.message
-      end
-    end
-
-    fields.each do |attr, messages|
-      errors[attr.to_sym] ||= []
-      errors[attr.to_sym].concat(Array(messages))
-    end
-
-    base_errors = Array(base) + Array(errors.delete(:base))
-
-    render json: { type: 'validation_error',
-                   message: '入力内容を確認してください．',
-                   errors:,
-                   base_errors: },
-           status:
-  end
 end

backend/app/controllers/deerjikists_controller.rb

@@ -2,8 +2,7 @@ class DeerjikistsController < ApplicationController
   def show
     platform = params[:platform].to_s.strip
     code = params[:code].to_s.strip
-    return render_bad_request('platform は必須です．') if platform.blank?
-    return render_bad_request('code は必須です．') if code.blank?
+    return head :bad_request if platform.blank? || code.blank?
 
     deerjikist = Deerjikist
                  .joins(:tag)
@@ -23,9 +22,7 @@ class DeerjikistsController < ApplicationController
     platform = params[:platform].to_s.strip
     code = params[:code].to_s.strip
     tag_id = params[:tag_id].to_i
-    return render_bad_request('platform は必須です．') if platform.blank?
-    return render_bad_request('code は必須です．') if code.blank?
-    return render_bad_request('tag_id が不正です．') if tag_id <= 0
+    return head :bad_request if platform.blank? || code.blank? || tag_id <= 0
 
     deerjikist = Deerjikist.find_or_initialize_by(platform:, code:).tap do |d|
       d.tag_id = tag_id
@@ -41,8 +38,7 @@ class DeerjikistsController < ApplicationController
 
     platform = params[:platform].to_s.strip
     code = params[:code].to_s.strip
-    return render_bad_request('platform は必須です．') if platform.blank?
-    return render_bad_request('code は必須です．') if code.blank?
+    return head :bad_request if platform.blank? || code.blank?
 
     Deerjikist.find([platform, code]).destroy!
 

backend/app/controllers/gekanator_games_controller.rb

@@ -1,272 +0,0 @@
-class GekanatorGamesController < ApplicationController
-  def create
-    return head :unauthorized unless current_user
-
-    guessed_post_id = params.require(:guessed_post_id)
-    correct_post_id = params[:correct_post_id].presence
-    answers = params.require(:answers).as_json
-
-    game = GekanatorGame.new(
-        user: current_user,
-        guessed_post_id:,
-        correct_post_id:,
-        won: correct_post_id.present? && guessed_post_id.to_i == correct_post_id.to_i,
-        question_count: answers.length,
-        answers:)
-
-    if game.invalid?
-      render json: { errors: game.errors.full_messages }, status: :unprocessable_entity
-      return
-    end
-
-    learned_example_count = 0
-
-    ActiveRecord::Base.transaction do
-      game.save!
-      learned_example_count = learn_answers_from_game!(game)
-    end
-
-    render json: {
-      id: game.id,
-      learned_example_count:
-    }, status: :created
-  rescue ActiveRecord::RecordInvalid => e
-    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_entity
-  end
-
-  def extra_questions
-    game = find_owned_game
-    return if performed?
-
-    questions =
-        GekanatorQuestion
-        .accepted
-        .includes(:gekanator_question_examples)
-        .where(kind: 'post_similarity', source: 'user_suggested')
-        .to_a
-
-    selected =
-        prioritized_extra_questions(
-            questions,
-            post_id: game.correct_post_id,
-            user: current_user,
-            limit: 6)
-
-    render json: {
-      questions: selected.map { |question| extra_question_json(question) }
-    }
-  end
-
-  def extra_question_answers
-    game = find_owned_game
-    return if performed?
-
-    answer_params = params.require(:answers)
-    if !answer_params.is_a?(Array)
-      return render_validation_error fields: { answers: ['配列で指定してください．'] }
-    end
-
-    answers = answer_params.map { |answer|
-      {
-        question_id: answer.require(:question_id).to_i,
-        answer: answer.require(:answer)
-      }
-    }
-    questions = GekanatorQuestion.where(id: answers.map { _1[:question_id] })
-    question_by_id = questions.index_by(&:id)
-    if questions.length != answers.length
-      return render_validation_error fields: { answers: ['質問が見つかりません．'] }
-    end
-    if questions.any? { |question| question.status != 'accepted' || question.kind != 'post_similarity' }
-      return render_validation_error fields: { answers: ['質問が不正です．'] }
-    end
-
-    ActiveRecord::Base.transaction do
-      answers.each do |item|
-        question = question_by_id[item[:question_id]]
-        example =
-            GekanatorQuestionExample.find_or_initialize_by(
-                gekanator_question: question,
-                post: game.correct_post,
-                user: current_user)
-        example.record_answer!(
-            answer: item[:answer],
-            source: 'post_game_extra',
-            gekanator_game: game)
-        example.save!
-      end
-    end
-
-    render json: { count: answers.length }, status: :created
-  end
-
-  private
-
-  def extra_question_json question
-    {
-      id: question.id,
-      text: question.text,
-      source: question.source,
-      priority_weight: question.priority_weight
-    }
-  end
-
-  def prioritized_extra_questions questions, post_id:, user:, limit:
-    answered_question_ids =
-        GekanatorQuestionExample
-        .where(user:, gekanator_question_id: questions.map(&:id))
-        .distinct
-        .pluck(:gekanator_question_id)
-    unanswered, answered =
-        questions.partition { |question| !answered_question_ids.include?(question.id) }
-    selected = weighted_sample_questions(unanswered, post_id:, limit:)
-    return selected if selected.length >= limit
-
-    selected + weighted_sample_questions(
-        answered.reject { |question| selected.any? { _1.id == question.id } },
-        post_id:,
-        limit: limit - selected.length)
-  end
-
-  def weighted_sample_questions questions, post_id:, limit:
-    remaining = questions.uniq(&:id)
-    selected = []
-
-    while selected.length < limit && remaining.any?
-      weighted =
-          remaining.map { |question|
-            [question, selection_weight_for(question, post_id: post_id)]
-          }
-      total_weight = weighted.sum { |_question, weight| weight }
-      break if total_weight <= 0
-
-      target = rand * total_weight
-      cumulative = 0.0
-      chosen =
-          weighted.find do |_question, weight|
-            cumulative += weight
-            cumulative >= target
-          end&.first || weighted.first.first
-
-      selected << chosen
-      remaining.reject! { |question| question.id == chosen.id }
-    end
-
-    selected
-  end
-
-  def selection_weight_for question, post_id:
-    sample_count =
-        question.gekanator_question_examples.sum { |example|
-          next 0 unless example.post_id == post_id
-
-          example.sample_count.presence || 1
-        }
-
-    question.priority_weight.to_f / (1.0 + sample_count * 0.15)
-  end
-
-  def find_owned_game
-    return head :unauthorized unless current_user
-
-    game = GekanatorGame.find_by(id: params[:id])
-    return head :not_found unless game
-    if !current_user.admin? && game.user_id != current_user.id
-      return head :not_found
-    end
-
-    game
-  end
-
-  def learn_answers_from_game! game
-    correct_post = game.correct_post
-    return 0 if correct_post.blank?
-
-    accepted_questions =
-        GekanatorQuestion
-        .accepted
-        .index_by { |question| public_question_id_for(question) }
-    learned_count = 0
-
-    Array(game.answers).each do |answer|
-      answer_value = answer['answer'].to_s
-      next if answer_value.blank? || answer_value == 'unknown'
-
-      question_id = game_answer_question_id(answer)
-      next if question_id.blank?
-
-      question = accepted_questions[question_id.to_s]
-      next unless learnable_game_answer_question?(question)
-
-      example =
-          GekanatorQuestionExample.find_or_initialize_by(
-              gekanator_question: question,
-              post: correct_post,
-              user: current_user)
-      example.record_answer!(
-          answer: answer_value,
-          source: 'post_game_answer',
-          gekanator_game: game)
-      example.save!
-      learned_count += 1
-    end
-
-    learned_count
-  end
-
-  def public_question_id_for question
-    condition = normalize_condition(question.condition)
-
-    case condition[:type]
-    when 'tag'
-      "tag:#{condition[:key]}"
-    when 'source'
-      "source:#{condition[:host]}"
-    when 'original-year'
-      "original-year:#{condition[:year]}"
-    when 'original-month'
-      "original-month:#{condition[:month]}"
-    when 'original-month-day'
-      "original-month-day:#{condition[:monthDay] || condition[:month_day]}"
-    when 'title-length-at-least'
-      "title:length-at-least:#{condition[:length]}"
-    when 'title-length-greater-than'
-      "title:length-at-least:#{condition[:length].to_i + 1}"
-    when 'title-has-ascii'
-      'title:ascii'
-    when 'title-contains'
-      "title:contains:#{condition[:text]}"
-    when 'post-similarity'
-      "post-similarity:#{question.id}"
-    else
-      "catalog:#{question.id}"
-    end
-  end
-
-  def normalize_condition condition
-    json = condition.deep_dup.as_json
-
-    if json['type'] == 'original-month-day' && json['monthDay'].blank?
-      json['monthDay'] = json.delete('month_day')
-    end
-
-    json.deep_symbolize_keys
-  end
-
-  def learnable_game_answer_question? question
-    return false if question.nil?
-    return true if question.kind == 'post_similarity'
-    return false unless question.kind == 'tag'
-
-    condition = normalize_condition(question.condition)
-    key = condition[:key].to_s
-    !key.start_with?('nico:')
-  end
-
-  def game_answer_question_id answer
-    answer['question_id'] ||
-      answer[:question_id] ||
-      answer['questionId'] ||
-      answer[:questionId]
-  end
-end

backend/app/controllers/gekanator_posts_controller.rb

@@ -1,71 +0,0 @@
-class GekanatorPostsController < ApplicationController
-  def index
-    posts =
-        Post
-        .preload(:post_similarities, tags: :tag_name)
-        .with_attached_thumbnail
-        .order(Arel.sql(
-            'COALESCE(posts.original_created_before - INTERVAL 1 MINUTE, ' \
-            'posts.original_created_from, posts.created_at) DESC, posts.id DESC'))
-        .to_a
-
-    active_tags_by_post_id =
-        posts.each_with_object({ }) do |post, h|
-          h[post.id] = post.tags.reject(&:deprecated?)
-        end
-
-    render json: {
-      posts: posts.map { |post|
-        post_json(post,
-                  active_tags_by_post_id:)
-      }
-    }
-  end
-
-  private
-
-  def post_json post, active_tags_by_post_id:
-    {
-      id: post.id,
-      url: post.url,
-      title: post.title,
-      thumbnail: thumbnail_url(post),
-      thumbnail_base: post.thumbnail_base,
-      original_created_from: post.original_created_from,
-      original_created_before: post.original_created_before,
-      post_similarity_edges: post_similarity_edges_json(
-          post,
-          active_tags_by_post_id:),
-      tags: active_tags_by_post_id.fetch(post.id, []).map { |tag| tag_json(tag) }
-    }
-  end
-
-  def post_similarity_edges_json post, active_tags_by_post_id:
-    post
-        .post_similarities
-        .filter_map do |similarity|
-          next unless active_tags_by_post_id.key?(similarity.target_post_id)
-
-          {
-            target_post_id: similarity.target_post_id,
-            cos: similarity.cos.to_f
-          }
-        end
-  end
-
-  def tag_json tag
-    {
-      id: tag.id,
-      name: tag.name,
-      category: tag.category
-    }
-  end
-
-  def thumbnail_url post
-    return nil unless post.thumbnail.attached?
-
-    rails_storage_proxy_url(post.thumbnail, only_path: false)
-  rescue
-    nil
-  end
-end

backend/app/controllers/gekanator_question_suggestions_controller.rb

@@ -1,95 +0,0 @@
-class GekanatorQuestionSuggestionsController < ApplicationController
-  def create
-    return head :unauthorized unless current_user
-
-    game = GekanatorGame.find_by(id: params.require(:gekanator_game_id))
-    return head :not_found unless game
-    if !current_user.admin? && game.user_id != current_user.id
-      return head :not_found
-    end
-
-    existing_question_id = params[:existing_question_id].presence
-    if existing_question_id
-      question = GekanatorQuestion.accepted.find_by(id: existing_question_id)
-      return head :not_found unless question
-      unless learnable_existing_question?(question)
-        return render_validation_error fields: { existing_question_id: ['質問が不正です．'] }
-      end
-
-      example =
-          GekanatorQuestionExample.find_or_initialize_by(
-              gekanator_question: question,
-              post: game.correct_post,
-              user: current_user)
-      example.record_answer!(
-          answer: params.require(:answer),
-          source: 'post_game_extra',
-          gekanator_game: game)
-
-      if example.save
-        render json: {
-          id: question.id,
-          count: game.question_suggestions.count
-        }, status: :created
-      else
-        render_validation_error example
-      end
-      return
-    end
-
-    suggestion = GekanatorQuestionSuggestion.new(
-        gekanator_game: game,
-        user: current_user,
-        question_text: params.require(:question_text),
-        answer: params.require(:answer))
-
-    if suggestion.valid?
-      ActiveRecord::Base.transaction do
-        suggestion.save!
-        Gekanator::QuestionSuggestionPromoter.call(
-            suggestion: suggestion,
-            user: current_user)
-      end
-
-      render json: {
-        id: suggestion.id,
-        count: game.question_suggestions.count
-      }, status: :created
-    else
-      render_validation_error suggestion
-    end
-  end
-
-  def ai_convert
-    return head :not_found unless current_user&.admin?
-
-    suggestion = GekanatorQuestionSuggestion.find_by(id: params[:id])
-    return head :not_found unless suggestion
-    if Gekanator::AiRunBudget.exceeded_after_next_run?
-      suggestion.gekanator_ai_runs.create!(
-          model: 'budget_guard',
-          status: 'blocked_budget',
-          input_tokens: 0,
-          output_tokens: 0,
-          estimated_cost_jpy: 0)
-      return head :payment_required
-    end
-
-    Gekanator::QuestionSuggestionAiConverter.call(
-        suggestion: suggestion,
-        user: current_user)
-    head :no_content
-  rescue NotImplementedError
-    head :not_implemented
-  end
-
-  private
-
-  def learnable_existing_question? question
-    return true if question.kind == 'post_similarity'
-    return false unless question.kind == 'tag'
-
-    key = question.condition.as_json['key'].to_s
-    !key.start_with?('nico:')
-  end
-end

backend/app/controllers/gekanator_questions_controller.rb

@@ -1,147 +0,0 @@
-class GekanatorQuestionsController < ApplicationController
-  def index
-    questions =
-        GekanatorQuestion
-        .accepted
-        .includes(:gekanator_question_examples)
-        .order(priority_weight: :desc, id: :asc)
-        .to_a
-    deprecated_tag_keys = deprecated_tag_keys_for(questions)
-
-    render json: {
-      questions: questions.filter_map { |question|
-        json = question_json(question)
-        next if hidden_question?(json[:condition], deprecated_tag_keys)
-
-        json
-      }
-    }
-  end
-
-  private
-
-  def question_json question
-    condition = condition_json(question.condition).deep_symbolize_keys
-    json = {
-      record_id: question.id,
-      id: question_id_for(question, condition),
-      text: question_text_for(question, condition),
-      kind: question.kind,
-      condition: condition,
-      source: question.source,
-      priority_weight: question.priority_weight
-    }
-    if question.kind == 'post_similarity' || question.kind == 'tag'
-      json[:example_answers] = example_answers_json(question)
-    end
-    json
-  end
-
-  def question_id_for question, condition
-    case condition[:type]
-    when 'tag'
-      "tag:#{ condition[:key] }"
-    when 'source'
-      "source:#{ condition[:host] }"
-    when 'original-year'
-      "original-year:#{ condition[:year] }"
-    when 'original-month'
-      "original-month:#{ condition[:month] }"
-    when 'original-month-day'
-      "original-month-day:#{ condition[:monthDay] || condition[:month_day] }"
-    when 'title-length-at-least'
-      "title:length-at-least:#{ condition[:length] }"
-    when 'title-length-greater-than'
-      "title:length-at-least:#{ condition[:length].to_i + 1 }"
-    when 'title-has-ascii'
-      'title:ascii'
-    when 'title-contains'
-      "title:contains:#{ condition[:text] }"
-    when 'post-similarity'
-      "post-similarity:#{ question.id }"
-    else
-      "catalog:#{ question.id }"
-    end
-  end
-
-  def condition_json condition
-    json = condition.deep_dup.as_json
-
-    if json['type'] == 'original-month-day' && json['monthDay'].blank?
-      json['monthDay'] = json.delete('month_day')
-    end
-
-    if json['type'] == 'title-length-greater-than'
-      json['type'] = 'title-length-at-least'
-      json['length'] = json['length'].to_i + 1
-    end
-
-    json
-  end
-
-  def question_text_for question, condition
-    return question.text unless question.kind == 'title'
-
-    case condition[:type]
-    when 'title-length-at-least'
-      "タイトルは #{ condition[:length] } 文字以上?"
-    when 'title-contains'
-      "題名に「#{ condition[:text] }」が含まれる?"
-    else
-      question.text
-    end
-  end
-
-  def example_answers_json question
-    question
-        .gekanator_question_examples
-        .group_by(&:post_id)
-        .transform_values { |examples| aggregate_answer(examples) }
-  end
-
-  def aggregate_answer examples
-    examples
-        .group_by(&:answer)
-        .map { |answer, grouped| [answer, grouped.sum(&:weight), grouped.max_by(&:updated_at)&.updated_at] }
-        .sort_by { |(_answer, weight, updated_at)| [-weight, -(updated_at&.to_f || 0)] }
-        .first
-        &.first
-  end
-
-  def deprecated_tag_keys_for questions
-    tag_keys = questions.filter_map { |question|
-      condition = condition_json(question.condition)
-      next unless condition['type'] == 'tag'
-
-      condition['key'].to_s.presence
-    }.uniq
-    return {} if tag_keys.empty?
-
-    categories = []
-    names = []
-    tag_keys.each do |key|
-      category, name = parse_tag_key(key)
-      categories << category
-      names << name
-    end
-
-    Tag
-        .joins(:tag_name)
-        .where(category: categories.uniq)
-        .where(tag_names: { name: names.uniq })
-        .where.not(deprecated_at: nil)
-        .pluck('tags.category', 'tag_names.name')
-        .each_with_object({ }) do |(category, name), h|
-          h["#{ category }:#{ name }"] = true
-        end
-  end
-
-  def hidden_question? condition, deprecated_tag_keys
-    condition[:type] == 'tag' && deprecated_tag_keys[condition[:key].to_s]
-  end
-
-  def parse_tag_key key
-    parts = key.to_s.split(':')
-    [parts.first.to_s, parts.drop(1).join(':')]
-  end
-end

backend/app/controllers/material_sync_suppressions_controller.rb

@@ -1,49 +0,0 @@
-class MaterialSyncSuppressionsController < ApplicationController
-  def index
-    return head :unauthorized unless current_user
-    return head :forbidden unless current_user.gte_member?
-
-    suppressions =
-        MaterialSyncSuppression
-        .includes(:created_by_user)
-        .order(created_at: :desc, id: :desc)
-
-    render json: { suppressions: suppressions.map { |s| repr(s) } }
-  end
-
-  def create
-    return head :unauthorized unless current_user
-    return head :forbidden unless current_user.gte_member?
-
-    suppression =
-        MaterialSyncSuppressionRegistrar.create!(suppression_params,
-                                                 created_by_user: current_user)
-
-    render json: repr(suppression), status: :created
-  rescue ActiveRecord::RecordInvalid => e
-    render_validation_error e.record
-  end
-
-  private
-
-  def suppression_params
-    params.permit(:source_kind,
-                  :source_uri,
-                  :drive_path,
-                  :drive_file_id,
-                  :reason)
-  end
-
-  def repr suppression
-    { id: suppression.id,
-      source_kind: suppression.source_kind,
-      source_uri: suppression.source_uri,
-      drive_path: suppression.drive_path,
-      drive_file_id: suppression.drive_file_id,
-      normalized_source_key: suppression.normalized_source_key,
-      reason: suppression.reason,
-      created_by_user: suppression.created_by_user&.as_json(UserRepr::BASE),
-      created_at: suppression.created_at,
-      updated_at: suppression.updated_at }
-  end
-end

backend/app/controllers/material_versions_controller.rb

@@ -1,54 +0,0 @@
-class MaterialVersionsController < ApplicationController
-  def index
-    page = (params[:page].presence || 1).to_i
-    limit = (params[:limit].presence || 20).to_i
-
-    page = 1 if page < 1
-    limit = 1 if limit < 1
-
-    offset = (page - 1) * limit
-
-    q = MaterialVersion.includes(:created_by_user)
-    q = q.where(material_id: params[:material_id]) if params[:material_id].present?
-    q = q.where(tag_name: params[:tag].to_s.strip) if params[:tag].present?
-    q = q.where(event_type: params[:event_type]) if params[:event_type].present?
-
-    count = q.except(:order, :limit, :offset).count
-    versions =
-        q
-        .order(Arel.sql('material_versions.created_at DESC, material_versions.id DESC'))
-        .limit(limit)
-        .offset(offset)
-
-    render json: { versions: serialise_versions(versions), count: }
-  end
-
-  private
-
-  def serialise_versions rows
-    rows.map do |row|
-      { id: row.id,
-        material_id: row.material_id,
-        version_no: row.version_no,
-        event_type: row.event_type,
-        tag_id: row.tag_id,
-        tag_name: row.tag_name,
-        tag_category: row.tag_category,
-        url: row.url,
-        source_kind: row.source_kind,
-        source_uri: row.source_uri,
-        source_path: row.source_path,
-        source_file_id: row.source_file_id,
-        normalized_source_key: row.normalized_source_key,
-        file_blob_id: row.file_blob_id,
-        file_filename: row.file_filename,
-        file_content_type: row.file_content_type,
-        file_byte_size: row.file_byte_size,
-        file_sha256: row.file_sha256,
-        export_paths_json: row.export_paths_hash,
-        discarded_at: row.discarded_at,
-        created_by_user: row.created_by_user&.as_json(UserRepr::BASE),
-        created_at: row.created_at }
-    end
-  end
-end

backend/app/controllers/materials_controller.rb

@@ -1,11 +1,4 @@
-require 'set'
-
-
 class MaterialsController < ApplicationController
-  rescue_from MaterialZipExporter::EmptyExportError, with: :render_zip_empty
-  rescue_from MaterialZipExporter::DuplicatePathError, with: :render_zip_duplicate_path
-  rescue_from MaterialZipExporter::MissingFileError, with: :render_zip_missing_file
-
   def index
     page = (params[:page].presence || 1).to_i
     limit = (params[:limit].presence || 20).to_i
@@ -15,101 +8,53 @@ class MaterialsController < ApplicationController
 
     offset = (page - 1) * limit
 
-    filters = material_index_filters
-    tag_graph = material_index_tag_graph(filters)
-    q = Material.includes(:material_export_items,
-                          thumbnail_attachment: :blob,
-                          file_attachment: :blob,
-                          tag: :tag_name)
-    q = q.where(tag_id: nil) if filters[:tag_state] == 'untagged'
-    q = q.where.not(tag_id: nil) if filters[:tag_state] == 'tagged'
-    q = apply_material_tag_filter(q, filters, tag_graph)
-    q = q.where('materials.created_at >= ?', filters[:created_from]) if filters[:created_from]
-    q = q.where('materials.created_at <= ?', filters[:created_to]) if filters[:created_to]
-    q = q.where('materials.updated_at >= ?', filters[:updated_from]) if filters[:updated_from]
-    q = q.where('materials.updated_at <= ?', filters[:updated_to]) if filters[:updated_to]
+    tag_id = params[:tag_id].presence
+    parent_id = params[:parent_id].presence
 
-    q = material_index_join_tag_name(q) if material_index_needs_tag_name?(filters)
-    q = material_index_join_file_blob(q) if material_index_needs_file_blob?(filters)
-    q = apply_material_query(q, filters[:q]) if filters[:q].present?
-    q = apply_material_media_kind(q, filters[:media_kind])
+    q = Material.includes(:tag, :created_by_user).with_attached_file
+    q = q.where(tag_id:) if tag_id
+    q = q.where(parent_id:) if parent_id
 
-    count = q.distinct.count(:id)
-    materials =
-        q
-        .order(Arel.sql(material_index_order_sql(filters)))
-        .limit(limit)
-        .offset(offset)
-        .to_a
+    count = q.count
+    materials = q.order(created_at: :desc, id: :desc).limit(limit).offset(offset)
 
-    response = { materials: MaterialRepr.list_many(materials, host: request.base_url),
-                 count: }
-    if filters[:tag_id]
-      response[:tag_scope] = material_index_tag_scope(filters, tag_graph)
-    end
-    if filters[:group_by] == 'parent_tag'
-      response[:groups] = material_index_groups(materials, tag_graph)
-    end
-
-    render json: response
+    render json: { materials: MaterialRepr.many(materials, host: request.base_url), count: count }
   end
 
   def show
     material =
         Material
-        .includes(:tag, :material_export_items)
-        .with_attached_thumbnail
+        .includes(:tag)
         .with_attached_file
         .find_by(id: params[:id])
     return head :not_found unless material
 
-    wiki_page_body = material.tag&.tag_name&.wiki_page&.current_revision&.body
+    wiki_page_body = material.tag.tag_name.wiki_page&.current_revision&.body
 
     render json: MaterialRepr.base(material, host: request.base_url).merge(wiki_page_body:)
   end
 
   def create
     return head :unauthorized unless current_user
-    return head :forbidden unless current_user.gte_member?
 
     tag_name_raw = params[:tag].to_s.strip
     file = params[:file]
-    file_sha256 = MaterialFileSha256.from_upload(file)
     url = params[:url].to_s.strip.presence
-    return render_unprocessable_entity('タグは必須です．', field: :tag) if tag_name_raw.blank?
-    if file.blank? && url.blank?
-      return render_validation_error fields: { file: ['ファイルまたは URL は必須です．'],
-                                               url: ['ファイルまたは URL は必須です．'] }
-    end
-    block = MaterialImportBlockMatcher.match_for_sha256(file_sha256)
-    return render_material_import_block(block) if block
+    return head :bad_request if tag_name_raw.blank? || (file.blank? && url.blank?)
 
-    uploaded_blob = build_uploaded_material_blob!(file, file_sha256)
-    material = nil
+    tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
+    tag = tag_name.tag
+    tag = Tag.create!(tag_name:, category: :material) unless tag
 
-    begin
-      Material.transaction do
-        tag = resolve_material_tag!(tag_name_raw)
-        material = Material.new(tag:, url:,
-                                created_by_user: current_user,
-                                updated_by_user: current_user)
-        material.file.attach(uploaded_blob) if uploaded_blob
-        material.save!
-        TagVersioning.record_tag_snapshot!(tag, created_by_user: current_user)
-        upsert_export_paths!(material)
-        MaterialVersionRecorder.record!(material:, event_type: :create,
-                                        created_by_user: current_user)
-      end
-    rescue StandardError
-      uploaded_blob&.purge_later
-      raise
-    end
+    material = Material.new(tag:, url:,
+                            created_by_user: current_user,
+                            updated_by_user: current_user)
+    material.file.attach(file)
 
-    if material
-      log_thumbnail_generation(material, MaterialThumbnailGenerator.generate!(material))
+    if material.save
       render json: MaterialRepr.base(material, host: request.base_url), status: :created
     else
-      render_validation_error material
+      render json: { errors: material.errors.full_messages }, status: :unprocessable_entity
     end
   end
 
@@ -122,42 +67,25 @@ class MaterialsController < ApplicationController
 
     tag_name_raw = params[:tag].to_s.strip
     file = params[:file]
-    file_sha256 = MaterialFileSha256.from_upload(file)
-    url = params.key?(:url) ? params[:url].to_s.strip.presence : material.url
-    return render_unprocessable_entity('タグは必須です．', field: :tag) if tag_name_raw.blank?
-    if file.blank? && url.blank? && !material.file.attached?
-      return render_validation_error fields: { file: ['ファイルまたは URL は必須です．'],
-                                               url: ['ファイルまたは URL は必須です．'] }
-    end
-    block = MaterialImportBlockMatcher.match_for_sha256(file_sha256)
-    return render_material_import_block(block) if block
+    url = params[:url].to_s.strip.presence
+    return head :bad_request if tag_name_raw.blank? || (file.blank? && url.blank?)
 
-    uploaded_blob = build_uploaded_material_blob!(file, file_sha256)
+    tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
+    tag = tag_name.tag
+    tag = Tag.create!(tag_name:, category: :material) unless tag
 
-    begin
-      Material.transaction do
-        MaterialVersionRecorder.ensure_snapshot!(material, created_by_user: current_user)
-        tag = resolve_material_tag!(tag_name_raw)
-        material.assign_attributes(tag:, url:, updated_by_user: current_user)
-        if uploaded_blob
-          material.file.attach(uploaded_blob)
-        elsif params.key?(:url) && url.present? && file.blank?
-          material.file.detach
-        end
-        material.save!
-        TagVersioning.record_tag_snapshot!(tag, created_by_user: current_user)
-        upsert_export_paths!(material)
-        MaterialVersionRecorder.record!(material:, event_type: :update,
-                                        created_by_user: current_user)
-      end
-    rescue StandardError
-      uploaded_blob&.purge_later
-      raise
+    material.update!(tag:, url:, updated_by_user: current_user)
+    if file
+      material.file.attach(file)
+    else
+      material.file.purge
     end
 
-    log_thumbnail_generation(material, MaterialThumbnailGenerator.generate!(material))
-
-    render json: MaterialRepr.base(material, host: request.base_url)
+    if material.save
+      render json: MaterialRepr.base(material, host: request.base_url)
+    else
+      render json: { errors: material.errors.full_messages }, status: :unprocessable_entity
+    end
   end
 
   def destroy
@@ -167,381 +95,7 @@ class MaterialsController < ApplicationController
     material = Material.find_by(id: params[:id])
     return head :not_found unless material
 
-    Material.transaction do
-      MaterialVersionRecorder.ensure_snapshot!(material, created_by_user: current_user)
-      material.discard!
-      MaterialVersionRecorder.record!(material:, event_type: :discard,
-                                      created_by_user: current_user)
-    end
+    material.discard
     head :no_content
   end
-
-  def download
-    zip = MaterialZipExporter.new(profile: params[:profile],
-                                  tag_id: params[:tag_id]).export
-    profile = params[:profile].presence || 'legacy_drive'
-    send_data zip,
-              type: 'application/zip',
-              disposition: 'attachment',
-              filename: "btrc-materials-#{ profile }.zip"
-  end
-
-  private
-
-  def material_index_filters
-    tag_state = params[:tag_state].to_s.presence
-    tag_state = 'untagged' if bool?(:unclassified)
-    tag_state = 'all' unless ['all', 'tagged', 'untagged'].include?(tag_state)
-
-    media_kind = params[:media_kind].to_s.presence
-    unless ['all', 'image', 'video', 'audio', 'file_other', 'url_only'].include?(media_kind)
-      media_kind = 'all'
-    end
-
-    sort = params[:sort].to_s.presence
-    unless ['created_at', 'updated_at', 'tag_name', 'media_kind', 'file_byte_size',
-            'version_no', 'id'].include?(sort)
-      sort = 'created_at'
-    end
-
-    direction = params[:direction].to_s.downcase
-    direction = 'desc' unless ['asc', 'desc'].include?(direction)
-
-    group_by = params[:group_by].to_s.presence
-    group_by = 'none' unless ['none', 'parent_tag'].include?(group_by)
-
-    tag_id = params[:tag_id].to_i
-    tag_id = nil if tag_id <= 0
-
-    { q: params[:q].to_s.strip.presence,
-      tag_state:,
-      media_kind:,
-      tag_id:,
-      include_descendants: bool?(:include_descendants),
-      group_by:,
-      created_from: parse_time_param(:created_from),
-      created_to: parse_time_param(:created_to),
-      updated_from: parse_time_param(:updated_from),
-      updated_to: parse_time_param(:updated_to),
-      sort:,
-      direction: }
-  end
-
-  def parse_time_param name
-    value = params[name].to_s.strip
-    return nil if value.blank?
-
-    Time.zone.parse(value)
-  rescue ArgumentError
-    nil
-  end
-
-  def resolve_material_tag! tag_name_raw
-    tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
-    tag = tag_name.tag
-    tag || Tag.create!(tag_name:, category: :material)
-  end
-
-  def material_index_needs_tag_name? filters
-    filters[:q].present? || filters[:sort] == 'tag_name'
-  end
-
-  def material_index_needs_file_blob? filters
-    filters[:q].present? ||
-        filters[:media_kind] != 'all' ||
-        ['media_kind', 'file_byte_size'].include?(filters[:sort])
-  end
-
-  def material_index_join_tag_name q
-    q.left_joins(tag: :tag_name)
-  end
-
-  def material_index_join_file_blob q
-    q.joins(<<~SQL.squish)
-      LEFT JOIN active_storage_attachments material_file_attachments
-        ON material_file_attachments.record_type = 'Material'
-       AND material_file_attachments.record_id = materials.id
-       AND material_file_attachments.name = 'file'
-      LEFT JOIN active_storage_blobs material_file_blobs
-        ON material_file_blobs.id = material_file_attachments.blob_id
-    SQL
-  end
-
-  def apply_material_query q, term
-    like = "%#{ ActiveRecord::Base.sanitize_sql_like(term) }%"
-    q.where('tag_names.name LIKE :q OR materials.url LIKE :q OR ' \
-            'material_file_blobs.filename LIKE :q',
-            q: like)
-  end
-
-  def apply_material_media_kind q, media_kind
-    case media_kind
-    when 'image'
-      q.where('material_file_blobs.content_type LIKE ?', 'image/%')
-    when 'video'
-      q.where('material_file_blobs.content_type LIKE ?', 'video/%')
-    when 'audio'
-      q.where('material_file_blobs.content_type LIKE ?', 'audio/%')
-    when 'file_other'
-      q.where('material_file_attachments.id IS NOT NULL')
-       .where.not('material_file_blobs.content_type LIKE ?', 'image/%')
-       .where.not('material_file_blobs.content_type LIKE ?', 'video/%')
-       .where.not('material_file_blobs.content_type LIKE ?', 'audio/%')
-    when 'url_only'
-      q.where('material_file_attachments.id IS NULL').where.not(url: [nil, ''])
-    else
-      q
-    end
-  end
-
-  def apply_material_tag_filter q, filters, tag_graph
-    return q unless filters[:tag_id]
-
-    tag_ids =
-        if tag_graph
-          tag_graph[:scope_tag_ids]
-        else
-          [filters[:tag_id]]
-        end
-
-    q.where(tag_id: tag_ids)
-  end
-
-  def material_index_tag_graph filters
-    return nil unless filters[:tag_id]
-
-    children_by_parent_id = Hash.new { |h, k| h[k] = [] }
-    TagImplication.pluck(:parent_tag_id, :tag_id).each do |parent_id, child_id|
-      children_by_parent_id[parent_id] << child_id
-    end
-
-    scope_tag_ids =
-        if filters[:include_descendants]
-          collect_material_descendant_ids(filters[:tag_id], children_by_parent_id)
-        else
-          Set.new([filters[:tag_id]])
-        end
-    tags_by_id =
-        Tag
-        .joins(:tag_name)
-        .where(id: scope_tag_ids)
-        .pluck('tags.id', 'tag_names.name', 'tags.category', 'tags.deprecated_at')
-        .each_with_object({ }) do |(id, name, category, deprecated_at), hash|
-          hash[id] = { id:, name:, category:, deprecated: deprecated_at.present? }
-        end
-
-    selected_tag = tags_by_id[filters[:tag_id]]
-    return nil unless selected_tag
-
-    group_tag_id_by_tag_id = { }
-    children_by_parent_id[filters[:tag_id]].each do |child_tag_id|
-      assign_material_group_branch(child_tag_id,
-                                   children_by_parent_id:,
-                                   tags_by_id:,
-                                   group_tag_id_by_tag_id:,
-                                   current_group_tag_id: nil,
-                                   seen: Set.new([filters[:tag_id]]))
-    end
-
-    { selected_tag_id: filters[:tag_id],
-      selected_tag:,
-      scope_tag_ids: scope_tag_ids.to_a,
-      tags_by_id:,
-      group_tag_id_by_tag_id: }
-  end
-
-  def collect_material_descendant_ids selected_tag_id, children_by_parent_id
-    ids = Set.new([selected_tag_id])
-    stack = [selected_tag_id]
-
-    until stack.empty?
-      tag_id = stack.pop
-      children_by_parent_id[tag_id].each do |child_tag_id|
-        next if ids.include?(child_tag_id)
-
-        ids << child_tag_id
-        stack << child_tag_id
-      end
-    end
-
-    ids
-  end
-
-  def assign_material_group_branch tag_id, children_by_parent_id:, tags_by_id:,
-                                   group_tag_id_by_tag_id:, current_group_tag_id:, seen:
-    return if seen.include?(tag_id)
-
-    tag = tags_by_id[tag_id]
-    return unless tag
-
-    seen = seen.dup << tag_id
-    next_group_tag_id = current_group_tag_id
-    next_group_tag_id = tag_id if next_group_tag_id.nil? && !tag[:deprecated]
-    group_tag_id_by_tag_id[tag_id] = next_group_tag_id if next_group_tag_id
-
-    children_by_parent_id[tag_id].each do |child_tag_id|
-      assign_material_group_branch(child_tag_id,
-                                   children_by_parent_id:,
-                                   tags_by_id:,
-                                   group_tag_id_by_tag_id:,
-                                   current_group_tag_id: next_group_tag_id,
-                                   seen:)
-    end
-  end
-
-  def material_index_groups materials, tag_graph
-    return [] unless tag_graph
-
-    groups_by_key = { }
-
-    materials.each do |material|
-      next unless material.tag_id
-
-      group_tag_id =
-          if material.tag_id == tag_graph[:selected_tag_id]
-            tag_graph[:selected_tag_id]
-          else
-            tag_graph[:group_tag_id_by_tag_id][material.tag_id] || tag_graph[:selected_tag_id]
-          end
-
-      group_tag = tag_graph[:tags_by_id][group_tag_id]
-      next unless group_tag
-
-      key = "tag:#{ group_tag_id }"
-      group =
-          groups_by_key[key] ||= { key:,
-                                   tag: group_tag_repr(group_tag),
-                                   material_ids: [],
-                                   count: 0 }
-      group[:material_ids] << material.id
-      group[:count] += 1
-    end
-
-    groups_by_key.values.sort_by { |group| group[:tag][:name] }
-  end
-
-  def material_index_tag_scope filters, tag_graph
-    return nil unless tag_graph
-
-    {
-      tag: group_tag_repr(tag_graph[:selected_tag]),
-      include_descendants: filters[:include_descendants]
-    }
-  end
-
-  def group_tag_repr group_tag
-    { id: group_tag[:id],
-      name: group_tag[:name],
-      category: group_tag[:category] }
-  end
-
-  def material_index_order_sql filters
-    direction = filters[:direction] == 'asc' ? 'ASC' : 'DESC'
-    sort_sql =
-        case filters[:sort]
-        when 'tag_name'
-          'tag_names.name'
-        when 'media_kind'
-          material_media_kind_sql
-        when 'file_byte_size'
-          'material_file_blobs.byte_size'
-        when 'updated_at'
-          'materials.updated_at'
-        when 'version_no'
-          'materials.version_no'
-        when 'id'
-          'materials.id'
-        else
-          'materials.created_at'
-        end
-
-    "#{ sort_sql } #{ direction }, materials.id #{ direction }"
-  end
-
-  def material_media_kind_sql
-    "CASE " \
-      "WHEN material_file_attachments.id IS NULL AND materials.url IS NOT NULL THEN 5 " \
-      "WHEN material_file_blobs.content_type LIKE 'image/%' THEN 1 " \
-      "WHEN material_file_blobs.content_type LIKE 'video/%' THEN 2 " \
-      "WHEN material_file_blobs.content_type LIKE 'audio/%' THEN 3 " \
-      "WHEN material_file_attachments.id IS NOT NULL THEN 4 " \
-      "ELSE 6 END"
-  end
-
-  def upsert_export_paths! material
-    raw = params[:export_paths]
-    return if raw.blank?
-
-    export_paths = raw.respond_to?(:to_unsafe_h) ? raw.to_unsafe_h : raw.to_h
-    export_paths.each do |profile, export_path|
-      profile = profile.to_s
-      export_path = export_path.to_s.strip
-      item = material.material_export_items.find_or_initialize_by(profile:)
-
-      if export_path.blank?
-        item.destroy! if item.persisted?
-        next
-      end
-
-      item.export_path = export_path
-      item.enabled = true
-      item.created_by_user ||= current_user
-      item.save!
-    end
-  end
-
-  def render_zip_empty
-    render_unprocessable_entity('ZIP export 対象の素材がありません．')
-  end
-
-  def render_zip_duplicate_path error
-    render_unprocessable_entity("ZIP export path が重複してゐます: #{ error.message }")
-  end
-
-  def render_zip_missing_file error
-    missing_files = error.missing_files.map do |missing_file|
-      { material_id: missing_file.material_id,
-        export_path: missing_file.export_path,
-        blob_id: missing_file.blob_id,
-        filename: missing_file.filename }
-    end
-
-    render json: { type: 'validation_error',
-                   message: 'ZIP export に必要な素材ファイルが欠損しています．',
-                   errors: { },
-                   base_errors: ['ZIP export に必要な素材ファイルが欠損しています．'],
-                   missing_files: },
-           status: :unprocessable_entity
-  end
-
-  def build_uploaded_material_blob! file, file_sha256
-    return nil unless file
-
-    file.tempfile.rewind
-
-    blob = ActiveStorage::Blob.create_and_upload!(
-        io: file.tempfile,
-        filename: file.original_filename,
-        content_type: file.content_type,
-    )
-
-    MaterialFileSha256.assign_metadata_sha256!(blob, file_sha256)
-
-    blob
-  ensure
-    file.tempfile.rewind if file&.tempfile
-  end
-
-  def render_material_import_block block
-    render_validation_error fields: { file: ["抑止された素材です: #{ block.reason }"] }
-  end
-
-  def log_thumbnail_generation material, result
-    material.reload
-    Rails.logger.info(
-        "Material thumbnail generation: material_id=#{ material.id } " \
-        "result=#{ result } " \
-        "thumbnail_attached=#{ material.thumbnail.attached? } " \
-        "content_type=#{ material.content_type }")
-  end
 end

backend/app/controllers/nico_tags_controller.rb

@@ -1,69 +1,26 @@
 class NicoTagsController < ApplicationController
   def index
-    name = params[:name].presence
-    linked_tag = params[:linked_tag].presence
-    link_status = params[:link_status].presence
-    order = params[:order].to_s.split(':', 2).map(&:strip)
-    order[0] = 'updated_at' unless order[0].in?(['name', 'created_at', 'updated_at'])
-    unless order[1].in?(['asc', 'desc'])
-      order[1] = order[0] == 'name' ? 'asc' : 'desc'
-    end
-    page = (params[:page].presence || 1).to_i
-    limit = (params[:limit].presence || 20).to_i
-
-    page = 1 if page < 1
-    limit = 1 if limit < 1
-
-    post_tag_max_sql =
-        PostTag
-        .select('tag_id, MAX(created_at) AS max_created_at')
-        .group('tag_id')
-        .to_sql
+    limit = (params[:limit] || 20).to_i
+    cursor = params[:cursor].presence
 
     q = Tag.nico_tags
-           .joins(:tag_name)
-           .joins("LEFT JOIN (#{ post_tag_max_sql }) post_tag_max " \
-                  'ON post_tag_max.tag_id = tags.id')
            .includes(:tag_name, tag_name: :wiki_page, linked_tags: { tag_name: :wiki_page })
-    q = q.where('tag_names.name LIKE ?', "%#{ name }%") if name
-    if linked_tag
-      linked_tag_ids =
-        Tag
-        .joins(:tag_name)
-        .where('tag_names.name LIKE ?', "%#{ linked_tag }%")
-        .pluck(:id)
-      linked_nico_tag_ids = NicoTagRelation.where(tag_id: linked_tag_ids).pluck(:nico_tag_id)
-      q = q.where(id: linked_nico_tag_ids)
-    end
-    if link_status.in?(['linked', 'unlinked'])
-      exists_sql =
-          'EXISTS (SELECT 1 FROM nico_tag_relations ' \
-          'WHERE nico_tag_relations.nico_tag_id = tags.id)'
-      q = link_status == 'linked' ? q.where(exists_sql) : q.where("NOT #{ exists_sql }")
-    end
+           .order(updated_at: :desc)
+    q = q.where('tags.updated_at < ?', Time.iso8601(cursor)) if cursor
 
-    count = q.count
-    sort_sql =
-        case order[0]
-        when 'name'
-          'tag_names.name'
-        when 'updated_at'
-          'post_tag_max.max_created_at'
-        else
-          "tags.#{ order[0] }"
-        end
-    tags = q.reselect('tags.*',
-                      Arel.sql('post_tag_max.max_created_at AS recent_post_tag_created_at'))
-            .order(Arel.sql("#{ sort_sql } #{ order[1] }, tags.id #{ order[1] }"))
-            .limit(limit)
-            .offset((page - 1) * limit)
-            .to_a
+    tags = q.limit(limit + 1).to_a
+
+    next_cursor = nil
+    if tags.size > limit
+      next_cursor = tags.last.updated_at.iso8601(6)
+      tags = tags.first(limit)
+    end
 
     render json: { tags: tags.map { |tag|
-      TagRepr.base(tag).merge(
-          recent_post_tag_created_at: tag.recent_post_tag_created_at,
-          linked_tags: tag.linked_tags.map { |lt| TagRepr.base(lt) })
-    }, count: }
+      TagRepr.base(tag).merge(linked_tags: tag.linked_tags.map { |lt|
+        TagRepr.base(lt)
+      })
+    }, next_cursor: }
   end
 
   def update
@@ -73,18 +30,14 @@ class NicoTagsController < ApplicationController
     id = params[:id].to_i
 
     tag = Tag.find(id)
-    return render_bad_request('ニコニコ・タグを指定してください．') unless tag.nico?
+    return head :bad_request unless tag.nico?
 
     linked_tag_names = params[:tags].to_s.split
-    linked_tags = nil
+    linked_tags = Tag.normalise_tags!(linked_tag_names, with_tagme: false,
+                                                        with_no_deerjikist: false)
+    return head :bad_request if linked_tags.any? { |t| t.nico? }
 
     ApplicationRecord.transaction do
-      linked_tags = Tag.normalise_tags!(linked_tag_names, with_tagme: false,
-                                                          with_no_deerjikist: false)
-      if linked_tags.any? { |t| t.nico? }
-        raise Tag::NicoTagNormalisationError
-      end
-
       TagVersioning.record_tag_snapshots!(linked_tags, created_by_user: current_user)
 
       tag.linked_tags = linked_tags
@@ -94,21 +47,5 @@ class NicoTagsController < ApplicationController
     end
 
     render json: tag.linked_tags.map { |t| TagRepr.base(t) }, status: :ok
-  rescue Tag::NicoTagNormalisationError
-    render_validation_error fields: { tags: ['ニコニコ・タグ同士は連携できません．'] }
-  rescue ActiveRecord::RecordInvalid => e
-    render_nico_tag_form_record_invalid e.record
-  end
-
-  private
-
-  def render_nico_tag_form_record_invalid record
-    if record.is_a?(TagName) || record.is_a?(Tag)
-      render_validation_error fields: { tags: record.errors.full_messages.map { |message|
-        "タグ名 “#{ record.name }”: #{ message }"
-      } }
-    else
-      render_validation_error record
-    end
   end
 end

backend/app/controllers/post_versions_controller.rb

@@ -25,7 +25,6 @@ class PostVersionsController < ApplicationController
         SQL
         .select('post_versions.*', 'prev.title AS prev_title', 'prev.url AS prev_url',
                 'prev.thumbnail_base AS prev_thumbnail_base', 'prev.tags AS prev_tags',
-                'prev.video_ms AS prev_video_ms',
                 'prev.original_created_from AS prev_original_created_from',
                 'prev.original_created_before AS prev_original_created_before')
     q = q.where('post_versions.post_id = ?', post_id) if post_id
@@ -75,10 +74,6 @@ class PostVersionsController < ApplicationController
           current: row.thumbnail_base,
           prev: row.attributes['prev_thumbnail_base']
         },
-        video_ms: {
-          current: row.video_ms,
-          prev: row.attributes['prev_video_ms']
-        },
         tags: build_version_tags(cur_tags, prev_tags),
         original_created_from: {
           current: row.original_created_from&.iso8601,

backend/app/controllers/posts_controller.rb

@@ -1,10 +1,5 @@
 class PostsController < ApplicationController
   Event = Struct.new(:post, :tag, :user, :change_type, :timestamp, keyword_init: true)
-  MAX_BULK_REQUEST_BYTES = 40 * 1024 * 1024
-
-  class VideoMsParseError < ArgumentError
-    ;
-  end
 
   def index
     url = params[:url].presence
@@ -49,10 +44,7 @@ class PostsController < ApplicationController
         filtered_posts
         .joins("LEFT JOIN (#{ pt_max_sql }) pt_max ON pt_max.post_id = posts.id")
         .reselect('posts.*', Arel.sql("#{ updated_at_all_sql } AS updated_at_all"))
-        .preload(:uploaded_user, :parents, :children,
-                 active_post_tags: [:sections,
-                                    { tag: [:deerjikists, :materials,
-                                            { tag_name: :wiki_page }] }])
+        .preload(tags: [:materials, { tag_name: :wiki_page }])
         .with_attached_thumbnail
 
     q = q.where('posts.url LIKE ?', "%#{ url }%") if url
@@ -103,11 +95,7 @@ class PostsController < ApplicationController
   end
 
   def random
-    post = filtered_posts.preload(:uploaded_user, :parents, :children,
-                                  active_post_tags: [:sections,
-                                                     { tag: [:deerjikists, :materials,
-                                                             { tag_name: :wiki_page }] }])
-                         .with_attached_thumbnail
+    post = filtered_posts.preload(tags: [:materials, { tag_name: :wiki_page }])
                          .order('RAND()')
                          .first
     return head :not_found unless post
@@ -115,175 +103,56 @@ class PostsController < ApplicationController
     render json: PostRepr.base(post, current_user)
   end
 
-  def metadata
-    return head :unauthorized unless current_user
-    return head :forbidden unless current_user.gte_member?
-    return render_bad_request('URL は必須です．') if params[:url].blank?
-
-    normal_url = PostUrlNormaliser.normalise(params[:url].to_s)
-    return render_validation_error(fields: { url: ['URL が不正です．'] }) if normal_url.blank?
-
-    Preview::UrlSafety.validate(normal_url)
-    existing_post = Post.with_attached_thumbnail.find_by(url: normal_url)
-    if existing_post.present?
-      return render json: {
-          url: normal_url,
-          title: nil,
-          thumbnail_base: nil,
-          tags: nil,
-          display_tags: [],
-          original_created_from: nil,
-          original_created_before: nil,
-          duration: nil,
-          video_ms: nil,
-          field_warnings: { },
-          base_warnings: [],
-          existing_post_id: existing_post.id,
-          existing_post: compact_post(existing_post.id) }
-    end
-
-    metadata = PostMetadataFetcher.fetch(normal_url)
-    field_warnings = { }
-    field_warnings[:title] = ['タイトルを取得できませんでした．'] if metadata[:title].blank?
-    if metadata[:thumbnail_base].blank?
-      field_warnings[:thumbnail_base] = ['サムネールを取得できませんでした．']
-    end
-
-    render json: {
-        url: normal_url,
-        title: metadata[:title],
-        thumbnail_base: metadata[:thumbnail_base],
-        tags: metadata[:tags],
-        display_tags: metadata[:display_tags],
-        original_created_from: metadata[:original_created_from],
-        original_created_before: metadata[:original_created_before],
-        duration: metadata[:duration],
-        video_ms: metadata[:video_ms],
-        field_warnings: field_warnings,
-        base_warnings: [],
-        existing_post_id: nil,
-        existing_post: nil }
-  rescue ArgumentError => e
-    render_bad_request e.message
-  rescue Preview::UrlSafety::UnsafeUrl => e
-    render_validation_error fields: { url: [e.message] }
-  rescue Preview::HttpFetcher::FetchFailed,
-         Preview::HttpFetcher::FetchTimeout,
-         Preview::HttpFetcher::ResponseTooLarge
-    render json: {
-        url: normal_url,
-        title: nil,
-        thumbnail_base: nil,
-        tags: nil,
-        display_tags: [],
-        original_created_from: nil,
-        original_created_before: nil,
-        duration: nil,
-        video_ms: nil,
-        field_warnings: { url: ['自動取得に失敗しました．'] },
-        base_warnings: [],
-        existing_post_id: nil,
-        existing_post: nil }
-  end
-
   def show
-    post =
-        Post
-        .includes(:uploaded_user, :parents, :children,
-                  active_post_tags: [:sections,
-                                     { tag: [:deerjikists, :materials,
-                                             { tag_name: :wiki_page }] }])
-        .with_attached_thumbnail
-        .find_by(id: params[:id])
+    post = Post.includes(tags: [:materials, { tag_name: :wiki_page }]).find_by(id: params[:id])
     return head :not_found unless post
 
-    parent_posts = post.parents.with_attached_thumbnail.order(:id).to_a
-    child_posts = post.children.with_attached_thumbnail.order(:id).to_a
-    sibling_posts = sibling_posts_by_parent(parent_posts.map(&:id))
-    related = post.related(limit: 20).to_a
-
-    render json: PostRepr.detail(post, current_user,
-                                 parent_posts:,
-                                 child_posts:,
-                                 sibling_posts:,
-                                 related:)
-                         .merge(tags: build_tag_tree_for(post))
+    render json: PostRepr.base(post, current_user)
+                         .merge(tags: build_tag_tree_for(post.tags),
+                                related: PostRepr.many(post.related(limit: 20)))
   end
 
   def create
     return head :unauthorized unless current_user
     return head :forbidden unless current_user.gte_member?
 
-    preflight = PostCreatePreflight.new(
-        attributes: post_create_attributes,
-        thumbnail: params[:thumbnail],
-        host: request.base_url).run
-    return render json: dry_run_json(preflight) if bool?(:dry)
-    if preflight[:existing_post_id].present?
-      post = Post.new(url: preflight[:url])
-      post.errors.add :url, :taken
-      return render_post_form_record_invalid post
-    end
+    # TODO: サイトに応じて thumbnail_base 設定
+    title = params[:title].presence
+    url = params[:url]
+    thumbnail = params[:thumbnail]
+    tag_names = params[:tags].to_s.split
+    original_created_from = params[:original_created_from]
+    original_created_before = params[:original_created_before]
+    parent_post_ids = parse_parent_post_ids
 
-    post = PostCreator.new(actor: current_user,
-                           attributes: post_create_attributes.merge(
-                               preflight.slice(
-                                   :url,
-                                   :title,
-                                   :thumbnail_base,
-                                   :tags,
-                                   :parent_post_ids,
-                                   :original_created_from,
-                                   :original_created_before,
-                                   :duration,
-                                   :video_ms,
-                                   :direct_tag_specs,
-                                   :default_tag_specs,
-                                   :snapshot_tag_specs,
-                                   :post_tag_specs,
-                                   :tag_sections,
-                                   :normalised_parent_post_ids).symbolize_keys).merge(
-                               thumbnail: params[:thumbnail])).create!
+    post = Post.new(title:, url:, thumbnail_base: nil, uploaded_user: current_user,
+                    original_created_from:, original_created_before:)
+    post.thumbnail.attach(thumbnail) if thumbnail.present?
+
+    ApplicationRecord.transaction do
+      post.save!
+
+      tags = Tag.normalise_tags!(tag_names)
+      TagVersioning.record_tag_snapshots!(tags, created_by_user: current_user)
+
+      tags = Tag.expand_parent_tags(tags)
+      sync_post_tags!(post, tags)
+
+      sync_parent_posts!(post, parent_post_ids)
+
+      post.resized_thumbnail!
+
+      PostVersionRecorder.record!(post:, event_type: :create, created_by_user: current_user)
+    end
 
     post.reload
     render json: PostRepr.base(post), status: :created
-  rescue PostCreatePreflight::ValidationFailed => e
-    render_validation_error fields: e.fields, base: e.base_errors
   rescue Tag::NicoTagNormalisationError
-    render_validation_error fields: { tags: 'ニコニコ・タグは直接指定できません．' }
-  rescue Tag::DeprecatedTagNormalisationError
-    render_unprocessable_entity '廃止済みタグは付与できません．', field: :tags
-  rescue Tag::SectionLiteralParseError
-    render_validation_error fields: { tags: ['タグ区間の記法が不正です．'] }
-  rescue PostCreator::VideoMsParseError
-    render_validation_error fields: { video_ms: ['動画時間の記法が不正です．'] }
-  rescue Post::RemoteThumbnailFetchFailed
-    render_validation_error fields: { thumbnail_base: ['サムネイル画像の取得に失敗しました．'] }
-  rescue MiniMagick::Error
-    render_validation_error fields: { thumbnail: ['サムネイル画像の変換に失敗しました．'] }
+    head :bad_request
   rescue ArgumentError => e
-    render_validation_error fields: { parent_post_ids: [e.message] }
+    render json: { errors: [e.message] }, status: :unprocessable_entity
   rescue ActiveRecord::RecordInvalid => e
-    render_post_form_record_invalid e.record
-  end
-
-  def bulk
-    return head :unauthorized unless current_user
-    return head :forbidden unless current_user.gte_member?
-    return head :unsupported_media_type unless request.content_mime_type == Mime[:multipart_form]
-    return head :payload_too_large if request.content_length.to_i > MAX_BULK_REQUEST_BYTES
-    posts = parse_bulk_posts_manifest
-    thumbnails = parse_bulk_thumbnails(posts.length)
-    result = PostBulkCreator.new(
-        actor: current_user,
-        posts:,
-        thumbnails:,
-        host: request.base_url).run
-    render json: result
-  rescue JSON::ParserError
-    render_bad_request 'posts manifest の JSON が不正です．'
-  rescue ArgumentError => e
-    render_validation_error base: [e.message]
+    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_entity
   end
 
   def viewed
@@ -304,84 +173,41 @@ class PostsController < ApplicationController
     return head :unauthorized unless current_user
     return head :forbidden unless current_user.gte_member?
 
-    force = bool?(:force)
-    merge = bool?(:merge)
-    return render_bad_request('force と merge は同時に指定できません．') if force && merge
-
-    base_version_no = parse_base_version_no
-    return render_bad_request('base_version_no は必須です．') if !(force) && !(base_version_no)
-
     title = params[:title].presence
     tag_names = params[:tags].to_s.split
     original_created_from = params[:original_created_from]
     original_created_before = params[:original_created_before]
     parent_post_ids = parse_parent_post_ids
 
-    post = nil
-    conflict_json = nil
+    post = Post.find(params[:id].to_i)
 
     ApplicationRecord.transaction do
-      post = Post.lock.find(params[:id].to_i)
+      PostVersionRecorder.ensure_snapshot!(post, created_by_user: current_user)
 
-      base_version = nil
-      base_snapshot = nil
-      current_snapshot = nil
-      unless force
-        base_version = post.post_versions.find_by!(version_no: base_version_no)
+      post.update!(title:, original_created_from:, original_created_before:)
 
-        base_snapshot = post_snapshot_from_version(base_version)
-        current_snapshot = post_snapshot_from_record(post)
-      end
-      incoming_snapshot = post_incoming_snapshot(title:,
-                                                 original_created_from:,
-                                                 original_created_before:,
-                                                 tag_names:,
-                                                 video_ms_param: params[:video_ms],
-                                                 duration_param: params[:duration],
-                                                 parent_post_ids:)
+      normalised_tags = Tag.normalise_tags!(tag_names, with_tagme: false)
+      TagVersioning.record_tag_snapshots!(normalised_tags, created_by_user: current_user)
 
-      snapshot_to_apply =
-          if force || post.version_no == base_version_no || current_snapshot == base_snapshot
-            incoming_snapshot
-          else
-            changes = post_snapshot_changes(base_snapshot, current_snapshot, incoming_snapshot)
-            conflicts = changes.select { |change| change[:conflict] }
+      tags = post.tags.nico.to_a + normalised_tags
+      tags = Tag.expand_parent_tags(tags)
+      sync_post_tags!(post, tags)
 
-            if merge && conflicts.empty?
-              merge_post_snapshots(base_snapshot, current_snapshot, incoming_snapshot)
-            else
-              conflict_json = post_conflict_json(post:,
-                                                 base_version_no:,
-                                                 base_snapshot:,
-                                                 current_snapshot:,
-                                                 incoming_snapshot:,
-                                                 changes:,
-                                                 conflicts:)
-              raise ActiveRecord::Rollback
-            end
-          end
+      sync_parent_posts!(post, parent_post_ids)
 
-      apply_post_snapshot!(post, snapshot_to_apply)
+      PostVersionRecorder.record!(post:, event_type: :update, created_by_user: current_user)
     end
 
-    return render json: conflict_json, status: :conflict if conflict_json
-
     post.reload
-    json = PostRepr.base(post, current_user)
-    json['tags'] = build_tag_tree_for(post)
+    json = post.as_json
+    json['tags'] = build_tag_tree_for(post.tags)
     render json:, status: :ok
   rescue Tag::NicoTagNormalisationError
-    render_validation_error fields: { tags: ['ニコニコ・タグは直接指定できません．'] }
-  rescue Tag::DeprecatedTagNormalisationError
-    render_unprocessable_entity '廃止済みタグは付与できません．', field: :tags
-  rescue Tag::SectionLiteralParseError
-    render_validation_error fields: { tags: ['タグ区間の記法が不正です．'] }
-  rescue VideoMsParseError
-    render_validation_error fields: { video_ms: ['動画時間の記法が不正です．'] }
+    head :bad_request
   rescue ArgumentError => e
-    render_validation_error fields: { parent_post_ids: [e.message] }
+    render json: { errors: [e.message] }, status: :unprocessable_entity
   rescue ActiveRecord::RecordInvalid => e
-    render_post_form_record_invalid e.record
+    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_entity
   end
 
   def changes
@@ -399,7 +225,7 @@ class PostsController < ApplicationController
     pts = pts.where(post_id: id) if id.present?
     pts = pts.where(tag_id:) if tag_id.present?
     pts = pts.includes(:post, :created_user, :deleted_user,
-                       tag: [:deerjikists, :materials, { tag_name: :wiki_page }])
+                       tag: [:materials, { tag_name: :wiki_page }])
 
     events = []
     pts.each do |pt|
@@ -476,7 +302,7 @@ class PostsController < ApplicationController
   def tagged_post_ids_for(name) =
       Post.joins(tags: :tag_name).where(tag_names: { name: }).select(:id)
 
-  def sync_post_tags! post, desired_tags, sections
+  def sync_post_tags! post, desired_tags
     desired_tags.each do |t|
       t.save! if t.new_record?
     end
@@ -495,21 +321,13 @@ class PostsController < ApplicationController
       end
     end
 
-    PostTagSection.where(post_id: post.id).destroy_all
-    sections.each do |tag_id, ranges|
-      ranges.each do |begin_ms, end_ms|
-        PostTagSection.create!(post_id: post.id, tag_id:, begin_ms:, end_ms:)
-      end
-    end
-
     PostTag.where(post_id: post.id, tag_id: to_remove.to_a).kept.find_each do |pt|
       pt.discard_by!(current_user)
     end
   end
 
-  def build_tag_tree_for post
-    post_tags = post.active_post_tags.reject { |post_tag| post_tag.tag.deprecated? }
-    tags = post_tags.map(&:tag)
+  def build_tag_tree_for tags
+    tags = tags.to_a
     tag_ids = tags.map(&:id)
 
     implications = TagImplication.where(parent_tag_id: tag_ids, tag_id: tag_ids)
@@ -524,9 +342,6 @@ class PostsController < ApplicationController
     root_ids = tag_ids - child_ids
 
     tags_by_id = tags.index_by(&:id)
-    sections_by_tag_id = post_tags.to_h { |post_tag|
-      [post_tag.tag_id, post_tag.sections.as_json(only: [:begin_ms, :end_ms])]
-    }
 
     memo = { }
 
@@ -534,10 +349,8 @@ class PostsController < ApplicationController
       tag = tags_by_id[tag_id]
       return nil unless tag
 
-      sections = sections_by_tag_id.fetch(tag_id, [])
-
       if path.include?(tag_id)
-        return TagRepr.inline(tag).merge(children: [], sections:)
+        return TagRepr.base(tag).merge(children: [])
       end
 
       if memo.key?(tag_id)
@@ -549,26 +362,12 @@ class PostsController < ApplicationController
 
       children = child_ids.filter_map { |cid| build_node.(cid, new_path) }
 
-      memo[tag_id] = TagRepr.inline(tag).merge(children:, sections:)
+      memo[tag_id] = TagRepr.base(tag).merge(children:)
     end
 
     root_ids.filter_map { |id| build_node.call(id, []) }
   end
 
-  def sibling_posts_by_parent parent_post_ids
-    return { } if parent_post_ids.blank?
-
-    implications =
-        PostImplication
-        .where(parent_post_id: parent_post_ids)
-        .includes(post: { thumbnail_attachment: :blob })
-        .order(:parent_post_id, :post_id)
-
-    implications.group_by(&:parent_post_id).transform_values { |items|
-      items.map(&:post)
-    }
-  end
-
   def parse_parent_post_ids
     raise ArgumentError, 'parent_post_ids は必須です．' unless params.key?(:parent_post_ids)
 
@@ -580,82 +379,9 @@ class PostsController < ApplicationController
     }.uniq
   end
 
-  def post_create_attributes
-    { title: params[:title],
-      url: params[:url],
-      thumbnail_base: params[:thumbnail_base],
-      tags: params[:tags],
-      original_created_from: params[:original_created_from],
-      original_created_before: params[:original_created_before],
-      parent_post_ids: parse_parent_post_ids,
-      video_ms: params[:video_ms],
-      duration: params[:duration] }
-  end
-
-  def parse_bulk_posts_manifest
-    manifest = params[:posts]
-    raise ArgumentError, 'posts は必須です．' if manifest.blank?
-    raise ArgumentError, 'posts は JSON 文字列で指定してください．' unless manifest.is_a?(String)
-
-    posts = JSON.parse(manifest)
-    raise ArgumentError, 'posts は配列で指定してください．' unless posts.is_a?(Array)
-    raise ArgumentError, '投稿件数は 1 件以上必要です．' if posts.empty?
-    raise ArgumentError, '投稿件数が多すぎます．' if posts.length > 100
-    raise ArgumentError, 'posts 要素の形式が不正です．' unless posts.all? { _1.is_a?(Hash) }
-
-    posts
-  end
-
-  def parse_bulk_thumbnails post_count
-    thumbnails = { }
-    raw = params[:thumbnails]
-    return thumbnails if raw.blank?
-    raise ArgumentError, 'thumbnail key が不正です．' unless raw.respond_to?(:to_unsafe_h)
-
-    raw.to_unsafe_h.each do |key, value|
-      raise ArgumentError, 'thumbnail key が不正です．' unless key.to_s.match?(/\A\d+\z/)
-
-      index = Integer(key, 10)
-      raise ArgumentError, 'thumbnail index が範囲外です．' if index.negative? || index >= post_count
-      raise ArgumentError, 'thumbnail index が重複しています．' if thumbnails.key?(index)
-      unless value.is_a?(ActionDispatch::Http::UploadedFile)
-        raise ArgumentError, 'thumbnail upload が不正です．'
-      end
-
-      thumbnails[index] = value
-    end
-
-    thumbnails
-  end
-
-  def compact_post post_id
-    return nil if post_id.blank?
-
-    post = Post.with_attached_thumbnail.find_by(id: post_id)
-    PostCompactRepr.base(post, host: request.base_url)
-  end
-
-  def dry_run_json preflight
-    preflight.slice(
-        :url,
-        :title,
-        :thumbnail_base,
-        :tags,
-        :display_tags,
-        :parent_post_ids,
-        :original_created_from,
-        :original_created_before,
-        :duration,
-        :video_ms,
-        :field_warnings,
-        :base_warnings,
-        :existing_post_id,
-        :existing_post)
-  end
-
   def sync_parent_posts! post, parent_post_ids
     if parent_post_ids.include?(post.id)
-      post.errors.add :parent_post_ids, '自分自身を親投稿にはできません．'
+      post.errors.add(:base, '自分自身を親投稿にはできません．')
       raise ActiveRecord::RecordInvalid, post
     end
 
@@ -663,8 +389,7 @@ class PostsController < ApplicationController
     missing_ids = parent_post_ids - existing_ids
 
     if missing_ids.present?
-      post.errors.add :parent_post_ids,
-                      "存在しない親投稿 Id. があります: #{ missing_ids.join(' ') }"
+      post.errors.add(:base, "存在しない親投稿 ID があります: #{ missing_ids.join(' ') }")
       raise ActiveRecord::RecordInvalid, post
     end
 
@@ -679,308 +404,4 @@ class PostsController < ApplicationController
       PostImplication.create_or_find_by!(post_id: post.id, parent_post_id:)
     end
   end
-
-  def parse_base_version_no
-    version_no = Integer(params[:base_version_no], exception: false)
-    if version_no&.positive?
-      version_no
-    else
-      nil
-    end
-  end
-
-  def post_snapshot_from_version version
-    { title: version.title,
-      video_ms: version.respond_to?(:video_ms) ? version.video_ms : nil,
-      original_created_from: snapshot_time(version.original_created_from),
-      original_created_before: snapshot_time(version.original_created_before),
-      tag_names: editable_tag_names_from_version(version),
-      parent_post_ids: snapshot_parent_post_ids_from_version(version) }
-  end
-
-  def editable_tag_names_from_version version
-    version.tags.to_s.split.reject { |name| name.downcase.start_with?('nico:') }.sort
-  end
-
-  def post_snapshot_from_record post
-    { title: post.title,
-      video_ms: post.video_ms,
-      original_created_from: snapshot_time(post.original_created_from),
-      original_created_before: snapshot_time(post.original_created_before),
-      tag_names: editable_tag_names_from_post(post),
-      parent_post_ids: post.parent_posts.order(:id).pluck(:id) }
-  end
-
-  def editable_tag_names_from_post post
-    post
-        .post_tags
-        .kept
-        .joins(tag: :tag_name)
-        .merge(Tag.not_nico)
-        .merge(Tag.where(deprecated_at: nil))
-        .includes(:sections, tag: :tag_name)
-        .order('tag_names.name')
-        .map do |post_tag|
-      name = post_tag.tag.tag_name.name
-      sections = post_tag.sections.sort_by(&:begin_ms)
-
-      next name if sections.empty?
-
-      "#{ name }#{ sections.map { Post.section_literal(_1) }.join }"
-    end
-  end
-
-  def post_incoming_snapshot title:, original_created_from:, original_created_before:,
-                             tag_names:, video_ms_param:, duration_param:, parent_post_ids:
-    validate_original_created_values!(original_created_from, original_created_before)
-    Tag.normalise_tags!(tag_names, with_tagme: false, deny_deprecated: true,
-                                        with_sections: true) =>
-        { tags:, sections: }
-
-    tags = Tag.expand_parent_tags(tags).reject(&:deprecated?)
-    video_ms = normalise_video_ms(tags, video_ms_param:, duration_param:)
-    validate_video_sections!(video_ms, sections)
-
-    { title:,
-      video_ms:,
-      original_created_from: snapshot_time(original_created_from),
-      original_created_before: snapshot_time(original_created_before),
-      tag_names: tags.uniq(&:id).map { |tag|
-        "#{ tag.name }#{ sections[tag.id].to_a.map { section_literal(_1) }.join }"
-      }.sort,
-      parent_post_ids: parent_post_ids.sort }
-  end
-
-  def snapshot_parent_post_ids_from_version version
-    if version.respond_to?(:parent_post_ids)
-      version.parent_post_ids.to_s.split.map { |id| id.to_i }.sort
-    elsif version.respond_to?(:parent_id) && version.parent_id
-      [version.parent_id]
-    else
-      []
-    end
-  end
-
-  def snapshot_time value
-    return nil if value.blank?
-
-    value = Time.zone.parse(value.to_s) if value in String
-    value&.in_time_zone&.iso8601(6)
-  rescue ArgumentError, TypeError
-    value.to_s
-  end
-
-  def validate_original_created_values! original_created_from, original_created_before
-    candidate = Post.new(
-        url: 'https://example.invalid/original-created-validation',
-        original_created_from:,
-        original_created_before:)
-    candidate.valid?
-    fields = [:original_created_from, :original_created_before, :original_created_at]
-    relevant_errors = candidate.errors.select { fields.include?(_1.attribute) }
-    return if relevant_errors.empty?
-
-    invalid_post = Post.new
-    relevant_errors.each { |error|
-      invalid_post.errors.add(error.attribute, error.message)
-    }
-    raise ActiveRecord::RecordInvalid, invalid_post
-  end
-
-  def section_literal section
-    "[#{ Post.ms_to_time(section[0]) }-#{ section[1] ? Post.ms_to_time(section[1]) : '' }]"
-  end
-
-  def post_conflict_json post:, base_version_no:, base_snapshot:,
-                         current_snapshot:, incoming_snapshot:, changes:, conflicts:
-    { error: 'conflict',
-      message: '競合が発生しました．',
-      post_id: post.id,
-      base_version_no:,
-      current_version_no: post.version_no,
-      base: base_snapshot,
-      current: current_snapshot,
-      mine: incoming_snapshot,
-      changes:,
-      conflicts:,
-      mergeable: conflicts.empty? }
-  end
-
-  def post_snapshot_changes base_snapshot, current_snapshot, incoming_snapshot
-    [scalar_snapshot_change(:title, 'タイトル',
-                            base_snapshot, current_snapshot, incoming_snapshot),
-     scalar_snapshot_change(:video_ms, '動画時間',
-                            base_snapshot, current_snapshot, incoming_snapshot),
-     scalar_snapshot_change(:original_created_from, 'オリジナルの作成日時（以降）',
-                            base_snapshot, current_snapshot, incoming_snapshot),
-     scalar_snapshot_change(:original_created_before, 'オリジナルの作成日時（より前）',
-                            base_snapshot, current_snapshot, incoming_snapshot),
-     set_snapshot_change(:tag_names, 'タグ',
-                         base_snapshot, current_snapshot, incoming_snapshot),
-     set_snapshot_change(:parent_post_ids, '親投稿',
-                         base_snapshot, current_snapshot, incoming_snapshot)].compact
-  end
-
-  def scalar_snapshot_change field, label, base_snapshot, current_snapshot, incoming_snapshot
-    base = base_snapshot[field]
-    current = current_snapshot[field]
-    mine = incoming_snapshot[field]
-
-    return nil if current == base && mine == base
-
-    { field:, label:, base:, current:, mine:,
-      changed_by_current: current != base,
-      changed_by_me: mine != base,
-      conflict: scalar_snapshot_conflict?(base, current, mine) }
-  end
-
-  def scalar_snapshot_conflict? base, current, mine
-    current != base && mine != base && current != mine
-  end
-
-  def set_snapshot_change field, label, base_snapshot, current_snapshot, incoming_snapshot
-    base = base_snapshot[field].to_a
-    current = current_snapshot[field].to_a
-    mine = incoming_snapshot[field].to_a
-
-    added_by_current = current - base
-    removed_by_current = base - current
-    added_by_me = mine - base
-    removed_by_me = base - mine
-
-    if (added_by_current.empty? &&
-        removed_by_current.empty? &&
-        added_by_me.empty? &&
-        removed_by_me.empty?)
-      return nil
-    end
-
-    { field:, label:, base:, current:, mine:, added_by_current:, removed_by_current:,
-      added_by_me:, removed_by_me:,
-      changed_by_current: added_by_current.present? || removed_by_current.present?,
-      changed_by_me: added_by_me.present? || removed_by_me.present?,
-      conflict: set_snapshot_conflict?(added_by_current:,
-                                       removed_by_current:,
-                                       added_by_me:,
-                                       removed_by_me:) }
-  end
-
-  def set_snapshot_conflict? added_by_current:, removed_by_current:,
-                             added_by_me:, removed_by_me:
-    (added_by_current & removed_by_me).present? || (removed_by_current & added_by_me).present?
-  end
-
-  def apply_post_snapshot! post, snapshot
-    PostVersionRecorder.ensure_snapshot!(post, created_by_user: current_user)
-
-    post.update!(title: snapshot[:title],
-                 video_ms: snapshot[:video_ms],
-                 original_created_from: snapshot[:original_created_from],
-                 original_created_before: snapshot[:original_created_before])
-
-    Tag.normalise_tags!(snapshot[:tag_names], with_tagme: false,
-                                               deny_deprecated: true,
-                                               with_sections: true) =>
-        { tags: editable_tags, sections: }
-    TagVersioning.record_tag_snapshots!(editable_tags, created_by_user: current_user)
-
-    readonly_tags = post.tags.nico.to_a
-
-    tags = readonly_tags + editable_tags
-    tags = Tag.expand_parent_tags(tags).reject(&:deprecated?)
-
-    post.video_ms = tags.any? { _1.id == Tag.video.id } ? snapshot[:video_ms] : nil
-    validate_video_sections!(post.video_ms, sections)
-    post.save!
-    sync_post_tags!(post, tags, sections)
-    sync_parent_posts!(post, snapshot[:parent_post_ids])
-
-    PostVersionRecorder.record!(post:, event_type: :update, created_by_user: current_user)
-  end
-
-  def merge_post_snapshots base_snapshot, current_snapshot, incoming_snapshot
-    [:title, :video_ms, :original_created_from, :original_created_before].map {
-      [_1, merge_scalar_snapshot_value(base_snapshot[_1],
-                                       current_snapshot[_1],
-                                       incoming_snapshot[_1])]
-    }.to_h.merge([:tag_names, :parent_post_ids].map {
-      [_1, merge_set_snapshot_value(base_snapshot[_1],
-                                    current_snapshot[_1],
-                                    incoming_snapshot[_1])]
-    }.to_h)
-  end
-
-  def merge_scalar_snapshot_value base, current, mine
-    return mine if current == base
-    return current if mine == base || current == mine
-
-    raise ArgumentError, '競合してゐる項目はマージできません．'
-  end
-
-  def merge_set_snapshot_value base, current, mine
-    base = base.to_a
-    current = current.to_a
-    mine = mine.to_a
-
-    added_by_current = current - base
-    removed_by_current = base - current
-    added_by_me = mine - base
-    removed_by_me = base - mine
-
-    merged = base + added_by_current + added_by_me
-    merged -= removed_by_current
-    merged -= removed_by_me
-
-    merged.uniq.sort
-  end
-
-  def render_post_form_record_invalid record
-    if record.is_a?(TagName) || record.is_a?(Tag)
-      render_validation_error fields: { tags: record.errors.full_messages.map { |message|
-        "タグ名 “#{ record.name }”: #{ message }"
-      } }
-    else
-      render_validation_error record
-    end
-  end
-
-  def normalise_video_ms tags, video_ms_param: params[:video_ms], duration_param: params[:duration]
-    return nil unless tags.any? { _1.id == Tag.video.id }
-
-    if video_ms_param.present?
-      video_ms = Integer(video_ms_param, exception: false)
-      raise VideoMsParseError unless video_ms&.positive?
-
-      return video_ms
-    end
-
-    return nil if duration_param.blank?
-
-    video_ms = Tag.time_to_ms!(duration_param.to_s, tag_name: '動画時間')
-    raise VideoMsParseError unless video_ms.positive?
-
-    video_ms
-  rescue Tag::SectionLiteralParseError
-    raise VideoMsParseError
-  end
-
-  def validate_video_sections! video_ms, sections
-    return unless video_ms
-
-    sections.each_value do |ranges|
-      ranges.each do |begin_ms, end_ms|
-        if begin_ms >= video_ms
-          post = Post.new
-          post.errors.add :video_ms, 'タグ区間の開始が動画時間以上です．'
-          raise ActiveRecord::RecordInvalid, post
-        end
-
-        if end_ms && end_ms > video_ms
-          post = Post.new
-          post.errors.add :video_ms, 'タグ区間の終端が動画時間を超えてゐます．'
-          raise ActiveRecord::RecordInvalid, post
-        end
-      end
-    end
-  end
 end

backend/app/controllers/preview_controller.rb

@@ -1,55 +1,46 @@
 class PreviewController < ApplicationController
-  before_action :require_member!
-
   def title
-    return render_bad_request('URL は必須です．') if params[:url].blank?
+    # TODO: # 既知サイトなら決まったフォーマットで title 取得するやぅに．
+    return head :unauthorized unless current_user
 
-    render json: { title: Preview::ThumbnailFetcher.title(params[:url]) }
-  rescue Preview::UrlSafety::UnsafeUrl => e
-    render_bad_request(e.message)
-  rescue Preview::HttpFetcher::FetchTimeout => e
-    render_preview_error(e.message, :gateway_timeout)
-  rescue Preview::HttpFetcher::ResponseTooLarge => e
-    render_preview_error(e.message, :payload_too_large)
-  rescue Preview::HttpFetcher::FetchFailed => e
-    render_preview_error(e.message, :bad_gateway)
+    url = params[:url]
+    return head :bad_request unless url.present?
+
+    unless url.start_with?(/http(s)?:\/\//)
+      url = 'http://' + url
+    end
+
+    html = URI.open(url, open_timeout: 5, read_timeout: 5).read
+    doc = Nokogiri::HTML.parse(html)
+    title = doc.at('title')&.text&.strip
+
+    render json: { title: title }
+  rescue => e
+    render json: { error: e.message }, status: :bad_request
   end
 
   def thumbnail
-    return render_bad_request('URL は必須です．') if params[:url].blank?
+    # TODO: 既知ドメインであれば指定のアドレスからサムネールを取得するやぅにする．
 
-    attachment =
-        Post.resized_thumbnail_attachment(
-            StringIO.new(Preview::ThumbnailFetcher.fetch(params[:url])))
-    send_data attachment[:io].read,
-              type: attachment[:content_type],
-              disposition: 'inline'
-  rescue Preview::UrlSafety::UnsafeUrl => e
-    render_bad_request(e.message)
-  rescue Preview::HttpFetcher::FetchTimeout => e
-    render_preview_error(e.message, :gateway_timeout)
-  rescue Preview::HttpFetcher::ResponseTooLarge => e
-    render_preview_error(e.message, :payload_too_large)
-  rescue Preview::HttpFetcher::FetchFailed => e
-    render_preview_error(e.message, :bad_gateway)
-  rescue Preview::ThumbnailFetcher::GenerationFailed, MiniMagick::Error => e
-    render_unprocessable_entity(e.message)
-  end
-
-  private
-
-  def require_member!
     return head :unauthorized unless current_user
-    return if current_user.gte_member?
 
-    head :forbidden
-  end
+    url = params[:url]
+    return head :bad_request if url.blank?
 
-  def render_preview_error(message, status)
-    render json: { type: status.to_s,
-                   message:,
-                   errors: { },
-                   base_errors: [message] },
-           status:
+    unless url.start_with?(/http(s)?:\/\//)
+      url = 'http://' + url
+    end
+
+    path = Rails.root.join('tmp', "thumb_#{ SecureRandom.hex }.png")
+    system("node #{ Rails.root }/lib/screenshot.js #{ Shellwords.escape(url) } #{ path }")
+
+    if File.exist?(path)
+      image = MiniMagick::Image.open(path)
+      image.resize '180x180'
+      File.delete(path) rescue nil
+      send_file image.path, type: 'image/png', disposition: 'inline'
+    else
+      render json: { error: 'Failed to generate thumbnail' }, status: :internal_server_error
+    end
   end
 end

backend/app/controllers/tag_children_controller.rb

@@ -5,12 +5,11 @@ class TagChildrenController < ApplicationController
 
     parent_id = params[:parent_id]
     child_id = params[:child_id]
-    return render_bad_request('parent_id は必須です．') if parent_id.blank?
-    return render_bad_request('child_id は必須です．') if child_id.blank?
+    return head :bad_request if parent_id.blank? || child_id.blank?
 
     parent = Tag.find(parent_id)
     child = Tag.find(child_id)
-    return render_bad_request('ニコニコ・タグの階層は変更できません．') if parent.nico? || child.nico?
+    return head :bad_request if parent.nico? || child.nico?
 
     ApplicationRecord.transaction do
       TagVersioning.ensure_snapshot!(child, created_by_user: current_user)
@@ -28,12 +27,11 @@ class TagChildrenController < ApplicationController
 
     parent_id = params[:parent_id]
     child_id = params[:child_id]
-    return render_bad_request('parent_id は必須です．') if parent_id.blank?
-    return render_bad_request('child_id は必須です．') if child_id.blank?
+    return head :bad_request if parent_id.blank? || child_id.blank?
 
     parent = Tag.find(parent_id)
     child = Tag.find(child_id)
-    return render_bad_request('ニコニコ・タグの階層は変更できません．') if parent.nico? || child.nico?
+    return head :bad_request if parent.nico? || child.nico?
 
     ApplicationRecord.transaction do
       TagVersioning.ensure_snapshot!(child, created_by_user: current_user)

backend/app/controllers/tag_versions_controller.rb

@@ -17,7 +17,6 @@ class TagVersionsController < ApplicationController
               AND prev.version_no = tag_versions.version_no - 1
         SQL
       .select('tag_versions.*', 'prev.name AS prev_name', 'prev.category AS prev_category',
-              'prev.deprecated_at AS prev_deprecated_at',
               'prev.aliases AS prev_aliases', 'prev.parent_tag_ids AS prev_parent_tag_ids')
     q = q.where('tag_versions.tag_id = ?', tag_id) if tag_id
 
@@ -63,8 +62,6 @@ class TagVersionsController < ApplicationController
         event_type: row.event_type,
         name: { current: row.name, prev: row.attributes['prev_name'] },
         category: { current: row.category, prev: row.attributes['prev_category'] },
-        deprecated_at: { current: row.deprecated_at&.iso8601,
-                         prev: row.attributes['prev_deprecated_at']&.iso8601 },
         aliases: build_version_values(cur_aliases, prev_aliases, key: :name),
         parent_tags:,
         created_at: row.created_at.iso8601,

backend/app/controllers/tags_controller.rb

@@ -1,8 +1,3 @@
-require 'net/http'
-require 'uri'
-require 'set'
-
-
 class TagsController < ApplicationController
   def index
     post_id = params[:post]
@@ -15,8 +10,6 @@ class TagsController < ApplicationController
     post_count_between[1] = nil if post_count_between[1] < 0
     created_between = params[:created_from].presence, params[:created_to].presence
     updated_between = params[:updated_from].presence, params[:updated_to].presence
-    deprecated_given = params.key?(:deprecated)
-    deprecated = bool?(:deprecated)
 
     order = params[:order].to_s.split(':', 2).map(&:strip)
     unless order[0].in?(['name', 'category', 'post_count', 'created_at', 'updated_at'])
@@ -51,9 +44,6 @@ class TagsController < ApplicationController
     q = q.where('tags.created_at <= ?', created_between[1]) if created_between[1]
     q = q.where('tags.updated_at >= ?', updated_between[0]) if updated_between[0]
     q = q.where('tags.updated_at <= ?', updated_between[1]) if updated_between[1]
-    if deprecated_given
-      q = deprecated ? q.where.not(deprecated_at: nil) : q.where(deprecated_at: nil)
-    end
 
     sort_sql =
         case order[0]
@@ -82,20 +72,39 @@ class TagsController < ApplicationController
   def with_depth
     parent_tag_id = params[:parent].to_i
     parent_tag_id = nil if parent_tag_id <= 0
-    material_filter = material_filter_param(default: 'any')
-
-    graph = build_with_depth_graph(material_filter)
 
     tag_ids =
         if parent_tag_id
-          visible_child_tag_ids(parent_tag_id, graph)
+          TagImplication.where(parent_tag_id:).select(:tag_id)
         else
-          visible_root_tag_ids(graph)
+          Tag.where.not(id: TagImplication.select(:tag_id)).select(:id)
         end
 
-    render json: tag_ids
-                 .sort_by { |tag_id| graph[:tags_by_id][tag_id][:name] }
-                 .map { |tag_id| with_depth_lightweight_repr(tag_id, graph) }
+    tags =
+        Tag
+        .joins(:tag_name)
+        .includes(:tag_name, :materials, tag_name: :wiki_page)
+        .where(category: [:meme, :character, :material])
+        .where(id: tag_ids)
+        .order('tag_names.name')
+        .distinct
+        .to_a
+
+    has_children_tag_ids =
+        if tags.empty?
+          []
+        else
+          TagImplication
+              .joins(:tag)
+              .where(parent_tag_id: tags.map(&:id),
+                     tags: { category: [:meme, :character, :material] })
+              .distinct
+              .pluck(:parent_tag_id)
+        end
+
+    render json: tags.map { |tag|
+      TagRepr.base(tag).merge(has_children: has_children_tag_ids.include?(tag.id), children: [])
+    }
   end
 
   def autocomplete
@@ -120,7 +129,6 @@ class TagsController < ApplicationController
 
     base = Tag.joins(:tag_name)
               .includes(:tag_name, :materials, tag_name: :wiki_page)
-              .where(deprecated_at: nil)
     base = base.where('tags.post_count > 0') if present_only
 
     canonical_hit =
@@ -156,7 +164,7 @@ class TagsController < ApplicationController
 
   def show_by_name
     name = params[:name].to_s.strip
-    return render_bad_request('name は必須です．') if name.blank?
+    return head :bad_request if name.blank?
 
     tag = Tag.joins(:tag_name)
              .includes(:tag_name, :materials, tag_name: :wiki_page)
@@ -174,62 +182,31 @@ class TagsController < ApplicationController
              .find_by(id: params[:id])
     return head :not_found unless tag
 
-    render json: { tag: TagRepr.base(tag),
-                   deerjikists: DeerjikistRepr.many(tag.deerjikists) }
+    render json: DeerjikistRepr.many(tag.deerjikists)
   end
 
   def deerjikists_by_name
     name = params[:name].to_s.strip
-    return render_bad_request('name は必須です．') if name.blank?
+    return head :bad_request if name.blank?
 
     tag = Tag.joins(:tag_name)
              .includes(:tag_name, tag_name: :wiki_page)
              .find_by(tag_names: { name: })
     return head :not_found unless tag
 
-    render json: { tag: TagRepr.base(tag),
-                   deerjikists: DeerjikistRepr.many(tag.deerjikists) }
-  end
-
-  def update_deerjikists
-    return head :unauthorized unless current_user
-    return head :forbidden unless current_user.gte_member?
-
-    tag = Tag.joins(:tag_name)
-             .includes(:tag_name, tag_name: :wiki_page)
-             .find_by(id: params[:id])
-    return head :not_found unless tag
-
-    ApplicationRecord.transaction do
-      tag.deerjikists = []
-      params[:_json].each.with_index do |item, i|
-        platform = item[:platform]
-        code = normalise_deerjikist_code(platform, item[:code])
-        deerjikist = Deerjikist.find_or_initialize_by(platform:, code:)
-        deerjikist.tag = tag
-        render_deerjikist_form_record_invalid(deerjikist, i) unless deerjikist.save
-        raise ActiveRecord::Rollback if performed?
-      end
-    end
-
-    return if performed?
-
-    render json: DeerjikistRepr.many(tag.reload.deerjikists)
+    render json: DeerjikistRepr.many(tag.deerjikists)
   end
 
   def materials_by_name
     name = params[:name].to_s.strip
-    return render_bad_request('name は必須です．') if name.blank?
-    material_filter = material_filter_param(default: 'any')
+    return head :bad_request if name.blank?
 
     tag = Tag.joins(:tag_name)
              .includes(:tag_name, :materials, tag_name: :wiki_page)
              .find_by(tag_names: { name: })
     return head :not_found unless tag
 
-    graph = build_with_depth_graph(material_filter)
-
-    render json: build_tag_children(tag, graph:)
+    render json: build_tag_children(tag)
   end
 
   def update_all
@@ -241,24 +218,22 @@ class TagsController < ApplicationController
 
     name = params[:name].to_s.strip
     category = params[:category].to_s.strip
-    return render_unprocessable_entity('名前は必須です．', field: :name) if name.blank?
-    return render_unprocessable_entity('カテゴリは必須です．', field: :category) if category.blank?
-    return render_unprocessable_entity '廃止状態は必須です．', field: :deprecated unless params.key?(:deprecated)
+    return head :unprocessable_entity if name.blank? || category.blank?
 
-    return unless validate_tag_rename(tag, name)
-
-    alias_names = params[:aliases].to_s.split.uniq
-    parent_names = params[:parent_tags].to_s.split.uniq
-    deprecated = bool?(:deprecated)
-
-    if tag.nico? && deprecated
-      return render_unprocessable_entity 'ニコタグは廃止できません．', field: :deprecated
+    if name != tag.name &&
+        tag.in?([Tag.tagme, Tag.bot, Tag.no_deerjikist, Tag.video, Tag.niconico])
+      return render json: { error: 'システム・タグの名称は変更できません．' },
+                    status: :unprocessable_entity
     end
 
     if tag.nico? || category == 'nico'
-      return render_unprocessable_entity 'ニコタグは変更できません．', field: :category
+      return render json: { error: 'ニコタグは変更できません．' },
+                    status: :unprocessable_entity
     end
 
+    alias_names = params[:aliases].to_s.split.uniq
+    parent_names = params[:parent_tags].to_s.split.uniq
+
     ApplicationRecord.transaction do
       TagVersioning.ensure_snapshot!(tag, created_by_user: current_user)
 
@@ -266,12 +241,8 @@ class TagsController < ApplicationController
       name_changed = name != old_name
       wiki_page = tag.tag_name.wiki_page if name_changed
 
-      if tag.deprecated? == deprecated
-        tag.update!(category:)
-      else
-        tag.update!(category:, deprecated_at: deprecated ? Time.current : nil)
-      end
-      rename_tag_name!(tag, name) if name_changed
+      tag.update!(category:)
+      tag.tag_name.update!(name:)
 
       alias_names << old_name if name_changed
       alias_names.delete(name)
@@ -298,19 +269,12 @@ class TagsController < ApplicationController
 
     name = params[:name].presence
     category = params[:category].presence
-    deprecated_given = params.key?(:deprecated)
-    deprecated = bool?(:deprecated)
 
     tag = Tag.find(params[:id])
 
-    if tag.nico? && deprecated_given && deprecated
-      return render_unprocessable_entity 'ニコタグは廃止できません．', field: :deprecated
-    end
-
-    return unless validate_tag_rename(tag, name)
-
     if tag.nico? || (category.present? && category == 'nico')
-      return render_unprocessable_entity 'ニコタグは変更できません．', field: :category
+      return render json: { error: 'ニコタグは変更できません．' },
+                    status: :unprocessable_entity
     end
 
     ApplicationRecord.transaction do
@@ -320,11 +284,8 @@ class TagsController < ApplicationController
       name_changed = name.present? && name != old_name
       wiki_page = tag.tag_name.wiki_page if name_changed
 
-      rename_tag_name!(tag, name) if name_changed
+      tag.tag_name.update!(name:) if name.present?
       tag.update!(category:) if category.present?
-      if deprecated_given && tag.deprecated? != deprecated
-        tag.update!(deprecated_at: deprecated ? Time.current : nil)
-      end
 
       tag.reload
 
@@ -341,178 +302,18 @@ class TagsController < ApplicationController
 
   private
 
-  def material_filter_param default:
-    value = params[:material_filter].to_s.presence
-    return default unless ['present', 'missing', 'any'].include?(value)
-
-    value
-  end
-
-  def build_with_depth_graph material_filter
-    children_by_parent_id = Hash.new { |h, k| h[k] = [] }
-    parent_ids_by_child_id = Hash.new { |h, k| h[k] = [] }
-
-    TagImplication.pluck(:parent_tag_id, :tag_id).each do |parent_id, child_id|
-      children_by_parent_id[parent_id] << child_id
-      parent_ids_by_child_id[child_id] << parent_id
-    end
-
-    tag_ids = (children_by_parent_id.keys +
-               parent_ids_by_child_id.keys +
-               Tag.where(category: ['meme', 'character', 'material']).pluck(:id)).uniq
-
-    material_tag_ids = Material.unscoped.kept.where.not(tag_id: nil).distinct.pluck(:tag_id).to_set
-
-    tags_by_id = Tag.joins(:tag_name)
-                    .where(id: tag_ids)
-                    .pluck('tags.id', 'tag_names.name', 'tags.category', 'tags.deprecated_at')
-                    .each_with_object({ }) do |(id, name, category, deprecated_at), h|
-      h[id] = { name:, category:, deprecated: deprecated_at.present?,
-                has_material: material_tag_ids.include?(id) }
-    end
-
-    { children_by_parent_id:, parent_ids_by_child_id:, tags_by_id:,
-      visible_child_tag_ids_by_parent_id: { },
-      visible_subtree_by_tag_id: { },
-      material_filter: }
-  end
-
-  def visible_root_tag_ids graph
-    root_ids = Set.new
-
-    graph[:tags_by_id].each do |tag_id, attrs|
-      next unless visible_root_tag?(tag_id, graph)
-      next unless visible_subtree?(tag_id, graph)
-
-      if attrs[:deprecated]
-        collect_visible_child_tag_ids(tag_id, graph, root_ids, Set.new)
-      else
-        root_ids << tag_id
-      end
-    end
-
-    root_ids.to_a
-  end
-
-  def visible_root_tag? tag_id, graph
-    seen = Set.new([tag_id])
-    stack = graph[:parent_ids_by_child_id][tag_id].dup
-
-    until stack.empty?
-      parent_id = stack.pop
-      next if seen.include?(parent_id)
-
-      seen << parent_id
-
-      parent = graph[:tags_by_id][parent_id]
-      next unless parent
-
-      return false unless parent[:deprecated]
-
-      stack.concat(graph[:parent_ids_by_child_id][parent_id])
-    end
-
-    true
-  end
-
-  def visible_child_tag_ids parent_tag_id, graph
-    cache = graph[:visible_child_tag_ids_by_parent_id]
-    return cache[parent_tag_id] if cache.key?(parent_tag_id)
-
-    visible_ids = Set.new
-
-    graph[:children_by_parent_id][parent_tag_id].each do |child_tag_id|
-      collect_visible_child_tag_ids(child_tag_id, graph, visible_ids, Set.new([parent_tag_id]))
-    end
-
-    cache[parent_tag_id] = visible_ids.to_a
-  end
-
-  def collect_visible_child_tag_ids tag_id, graph, visible_ids, seen
-    return if seen.include?(tag_id)
-
-    seen = seen.dup << tag_id
-    tag = graph[:tags_by_id][tag_id]
-    return unless tag
-
-    if tag[:deprecated]
-      graph[:children_by_parent_id][tag_id].each do |child_tag_id|
-        collect_visible_child_tag_ids(child_tag_id, graph, visible_ids, seen)
-      end
-      return
-    end
-
-    if with_depth_visible_tag?(tag, graph[:material_filter])
-      visible_ids << tag_id
-      return
-    end
-
-    visible_ids << tag_id if graph[:children_by_parent_id][tag_id].any? { |child_tag_id|
-      visible_subtree?(child_tag_id, graph)
-    }
-  end
-
-  def with_depth_visible_tag? tag, material_filter
-    return false unless tag[:category].in?(['meme', 'character', 'material']) && !tag[:deprecated]
-
-    case material_filter
-    when 'present'
-      tag[:has_material]
-    when 'missing'
-      !tag[:has_material]
-    else
-      true
-    end
-  end
-
-  def visible_subtree? tag_id, graph
-    cache = graph[:visible_subtree_by_tag_id]
-    return cache[tag_id] if cache.key?(tag_id)
-
-    tag = graph[:tags_by_id][tag_id]
-    return cache[tag_id] = false unless tag
-
-    if tag[:deprecated]
-      return cache[tag_id] =
-                 graph[:children_by_parent_id][tag_id].any? { |child_tag_id|
-                   visible_subtree?(child_tag_id, graph)
-                 }
-    end
-
-    cache[tag_id] =
-        with_depth_visible_tag?(tag, graph[:material_filter]) ||
-        graph[:children_by_parent_id][tag_id].any? { |child_tag_id|
-          visible_subtree?(child_tag_id, graph)
-        }
-  end
-
-  def with_depth_lightweight_repr tag_id, graph
-    tag = graph[:tags_by_id][tag_id]
-
-    { id: tag_id,
-      name: tag[:name],
-      category: tag[:category],
-      deprecated: tag[:deprecated],
-      has_material: tag[:has_material],
-      has_children: visible_child_tag_ids(tag_id, graph).present?,
-      children: [] }
-  end
-
-  def build_tag_children tag, graph: nil
+  def build_tag_children tag
     material = tag.materials.first
-    tag_graph = graph && graph[:tags_by_id][tag.id]
-    material =
-        nil if tag_graph && !with_depth_visible_tag?(tag_graph, graph[:material_filter])
-
-    children = tag.children.sort_by(&:name)
-    if graph
-      children = children.filter { |child_tag| visible_subtree?(child_tag.id, graph) }
+    file = nil
+    content_type = nil
+    if material&.file&.attached?
+      file = rails_storage_proxy_url(material.file, only_path: false)
+      content_type = material.file.blob.content_type
     end
 
     TagRepr.base(tag).merge(
-        children: children.map { build_tag_children(_1, graph:) },
-        has_material: tag_graph ? tag_graph[:has_material] : material.present?,
-        material: material && MaterialRepr.base(material, host: request.base_url))
+        children: tag.children.sort_by { _1.name }.map { build_tag_children(_1) },
+        material: material.as_json&.merge(file:, content_type:))
   end
 
   def record_tag_version! tag, event_type:, created_by_user:, name_changed: false, wiki_page: nil
@@ -534,67 +335,6 @@ class TagsController < ApplicationController
         created_by_user:)
   end
 
-  def validate_tag_rename tag, name
-    return true if name.blank? || name == tag.name
-
-    if tag.in?([Tag.tagme, Tag.bot, Tag.no_deerjikist, Tag.video, Tag.niconico])
-      render_unprocessable_entity 'システム・タグの名称は変更できません．', field: :name
-      return false
-    end
-
-    target_tag_name = TagName.with_discarded.find_by(name:)
-    return true if target_tag_name.nil?
-    return true if target_tag_name.canonical_id?
-
-    render_unprocessable_entity 'その名前は既に使はれてゐます．', field: :name
-    false
-  end
-
-  def rename_tag_name! tag, name
-    return if name == tag.name
-
-    current_tag_name = tag.tag_name
-    target_tag_name = TagName.with_discarded.find_by(name:)
-
-    if target_tag_name.nil?
-      current_tag_name.update!(name:)
-      return
-    end
-
-    promote_tag_alias!(
-        tag,
-        current_tag_name:,
-        promoted_tag_name: target_tag_name)
-  end
-
-  def promote_tag_alias! tag, current_tag_name:, promoted_tag_name:
-    old_owner_tag = promoted_tag_name.canonical&.tag
-
-    if old_owner_tag && old_owner_tag != tag
-      TagVersioning.ensure_snapshot!(old_owner_tag, created_by_user: current_user)
-    end
-
-    promoted_tag_name.undiscard! if promoted_tag_name.discarded?
-    promoted_tag_name.update!(canonical: nil)
-
-    TagName.with_discarded
-           .where(canonical_id: current_tag_name.id)
-           .where.not(id: promoted_tag_name.id)
-           .find_each do |alias_tag_name|
-      alias_tag_name.update!(canonical: promoted_tag_name)
-    end
-
-    current_tag_name.wiki_page&.update!(tag_name: promoted_tag_name)
-    tag.update!(tag_name: promoted_tag_name)
-    current_tag_name.association(:wiki_page).reset
-    current_tag_name.association(:tag).reset
-    current_tag_name.reload.update!(canonical: promoted_tag_name)
-
-    return unless old_owner_tag && old_owner_tag != tag
-
-    record_tag_version!(old_owner_tag.reload, event_type: :update, created_by_user: current_user)
-  end
-
   def update_aliases! tag, alias_names
     alias_names = alias_names.uniq
 
@@ -651,40 +391,4 @@ class TagsController < ApplicationController
       TagImplication.create!(tag:, parent_tag:)
     end
   end
-
-  def normalise_deerjikist_code platform, code
-    return code if platform != 'youtube' || code[0] != '@'
-
-    url = "https://www.youtube.com/#{ code }"
-
-    html = Net::HTTP.get(URI(url))
-
-    canonical = html[
-        /<link rel="canonical" href="https:\/\/www\.youtube\.com\/channel\/(UC[a-zA-Z0-9_-]{22})"/,
-        1]
-    return canonical if canonical
-
-    html[/"channelId":"(UC[a-zA-Z0-9_-]{22})"/, 1] || html[/\bUC[a-zA-Z0-9_-]{22}\b/]
-  rescue
-    nil
-  end
-
-  def render_deerjikist_form_record_invalid deerjikist, index
-    fields = { }
-
-    deerjikist.errors.each do |error|
-      field =
-          case error.attribute
-          when :platform, :code
-            "deerjikists.#{ index }.#{ error.attribute }"
-          else
-            :deerjikists
-          end
-
-      fields[field] ||= []
-      fields[field] << error.full_message
-    end
-
-    render_validation_error fields:
-  end
 end

backend/app/controllers/theatre_comments_controller.rb

@@ -1,28 +1,21 @@
 class TheatreCommentsController < ApplicationController
   def index
-    limit = params[:limit].to_i
-    limit = 20 if limit <= 0
-
     no_gt = params[:no_gt].to_i
-    no_gt = 0 if no_gt < 0
+    no_gt = 0 if no_gt.negative?
 
     comments = TheatreComment
                .where(theatre_id: params[:theatre_id])
                .where('no > ?', no_gt)
                .order(no: :desc)
-               .limit(limit)
 
-    render json: comments.map {
-      _1.as_json(include: { user: { only: [:id, :name] } })
-          .merge(content: _1.discarded? ? nil : _1.content, deleted: _1.discarded?)
-    }
+    render json: comments.as_json(include: { user: { only: [:id, :name] } })
   end
 
   def create
     return head :unauthorized unless current_user
 
     content = params[:content]
-    return render_unprocessable_entity('本文は必須です．', field: :content) if content.blank?
+    return head :unprocessable_entity if content.blank?
 
     theatre = Theatre.find_by(id: params[:theatre_id])
     return head :not_found unless theatre
@@ -36,19 +29,4 @@ class TheatreCommentsController < ApplicationController
 
     render json: comment, status: :created
   end
-
-  def destroy
-    return head :unauthorized unless current_user
-
-    theatre_id = params[:theatre_id].to_i
-    no = params[:id].to_i
-
-    comment = TheatreComment.find_by(theatre_id:, no:)
-    return head :not_found unless comment
-    return head :forbidden unless comment.user == current_user
-
-    comment.discard!
-
-    head :no_content
-  end
 end

backend/app/controllers/theatre_programmes_controller.rb

@@ -1,22 +0,0 @@
-class TheatreProgrammesController < ApplicationController
-  def index
-    limit = params[:limit].to_i
-    limit = 100 if limit <= 0
-
-    position_gt = params[:position_gt].to_i
-    position_gt = 0 if position_gt < 0
-
-    programmes = TheatreProgramme
-                 .where(theatre_id: params[:theatre_id])
-                 .where('position > ?', position_gt)
-                 .includes(:post)
-                 .order(position: :desc).limit(100)
-                 .limit(limit)
-
-    render json: programmes.map { |programme|
-      programme.as_json.merge(post: { id: programme.post.id,
-                                      title: programme.post.title,
-                                      url: programme.post.url })
-    }
-  end
-end

backend/app/controllers/theatre_skip_events_controller.rb

@@ -1,22 +0,0 @@
-class TheatreSkipEventsController < ApplicationController
-  def index
-    limit = params[:limit].to_i
-    limit = 50 if limit <= 0
-
-    events =
-        TheatreSkipEvent
-        .where(theatre_id: params[:theatre_id])
-        .includes(:post, tags: :tag_name)
-        .order(created_at: :desc)
-        .limit(limit)
-
-    render json: events.map { |event|
-      { id: event.id,
-        theatre_id: event.theatre_id,
-        post: { id: event.post.id, title: event.post.title, url: event.post.url },
-        tags: event.tags.map { |tag| { id: tag.id, name: tag.name } },
-        programme_position: event.programme_position,
-        created_at: event.created_at }
-    }
-  end
-end

backend/app/controllers/theatres_controller.rb

@@ -31,7 +31,9 @@ class TheatresController < ApplicationController
       post_started_at = theatre.current_post_started_at
     end
 
-    render json: theatre_info_json(theatre, host_flg:, post_id:, post_started_at:)
+    render json: {
+        host_flg:, post_id:, post_started_at:,
+        watching_users: theatre.watching_users.as_json(only: [:id, :name]) }
   end
 
   def next_post
@@ -41,119 +43,12 @@ class TheatresController < ApplicationController
     return head :not_found unless theatre
     return head :forbidden if theatre.host_user != current_user
 
-    ApplicationRecord.transaction do
-      theatre.lock!
-      TheatrePostAdvancer.call(theatre:)
-    end
+    post = Post.where("url LIKE '%nicovideo.jp%'")
+           .or(Post.where("url LIKE '%youtube.com%'"))
+           .order('RAND()')
+           .first
+    theatre.update!(current_post: post, current_post_started_at: Time.current)
 
     head :no_content
   end
-
-  def skip_vote
-    return head :unauthorized unless current_user
-
-    theatre = Theatre.find_by(id: params[:id])
-    return head :not_found unless theatre
-    requested_post_id = params[:post_id].to_i
-    return head :unprocessable_entity if requested_post_id <= 0
-
-    skipped = false
-    conflicted = false
-
-    ApplicationRecord.transaction do
-      theatre.lock!
-      if theatre.current_post
-        TheatreWatchingUser.find_or_initialize_by(theatre:, user: current_user).tap {
-          _1.expires_at = 30.seconds.from_now
-        }.save!
-
-        if theatre.current_post_id != requested_post_id
-          conflicted = true
-          next
-        end
-
-        TheatreSkipVote.find_or_create_by!(theatre:, post_id: requested_post_id, user: current_user)
-
-        vote_status = skip_vote_status(theatre)
-        if vote_status[:votes_count] >= vote_status[:required_count]
-          TheatreSkipFinalizer.call(theatre:, user: current_user)
-          TheatrePostAdvancer.call(theatre:)
-          skipped = true
-        end
-      end
-    end
-
-    theatre.reload
-    return render json: theatre_info_json(theatre, skipped: false), status: :conflict if conflicted
-
-    render json: theatre_info_json(theatre, skipped:)
-  end
-
-  def unskip_vote
-    return head :unauthorized unless current_user
-
-    theatre = Theatre.find_by(id: params[:id])
-    return head :not_found unless theatre
-    requested_post_id = params[:post_id].to_i
-    return head :unprocessable_entity if requested_post_id <= 0
-
-    conflicted = false
-
-    theatre.with_lock do
-      if theatre.current_post
-        if theatre.current_post_id != requested_post_id
-          conflicted = true
-        else
-          TheatreSkipVote.where(theatre:, post_id: requested_post_id, user: current_user).delete_all
-        end
-      end
-    end
-
-    theatre.reload
-    return render json: theatre_info_json(theatre, skipped: false), status: :conflict if conflicted
-
-    render json: theatre_info_json(theatre, skipped: false)
-  end
-
-  def post_selection_weights
-    theatre = Theatre.find_by(id: params[:id])
-    return head :not_found unless theatre
-
-    render json: TheatrePostSelector.new(theatre:).weight_json
-  end
-
-  private
-
-  def theatre_info_json(theatre, host_flg: nil, post_id: nil, post_started_at: nil, skipped: nil)
-    host_flg = theatre.host_user_id == current_user&.id if host_flg.nil?
-    post_id = theatre.current_post_id if post_id.nil?
-    post_started_at = theatre.current_post_started_at if post_started_at.nil?
-
-    json = { host_flg:,
-             post_id:,
-             post_started_at:,
-             post_elapsed_ms: post_started_at ? ((Time.current - post_started_at) * 1000).floor : nil,
-             watching_users: theatre.watching_users.as_json(only: [:id, :name]),
-             skip_vote: skip_vote_status(theatre) }
-    json[:skipped] = skipped unless skipped.nil?
-    json
-  end
-
-  def skip_vote_status(theatre)
-    watching_user_ids = theatre.watching_users.ids
-    watching_users_count = watching_user_ids.size
-    required_count = (watching_users_count / 2) + 1
-    post = theatre.current_post
-    votes =
-        if post
-          TheatreSkipVote.where(theatre:, post:, user_id: watching_user_ids)
-        else
-          TheatreSkipVote.none
-        end
-
-    { votes_count: post ? votes.count : 0,
-      required_count:,
-      watching_users_count:,
-      voted: post && current_user ? votes.exists?(user_id: current_user.id) : false }
-  end
 end

backend/app/controllers/user_settings_controller.rb

@@ -1,61 +0,0 @@
-class UserSettingsController < ApplicationController
-  wrap_parameters false
-
-  def show
-    return head :unauthorized unless current_user
-
-    render json: current_setting.serializable_hash
-  end
-
-  def update
-    return head :unauthorized unless current_user
-
-    raw_attributes = editable_raw_attributes
-    field_errors = validate_raw_attributes(raw_attributes)
-    return render_validation_error fields: field_errors if field_errors.present?
-
-    setting = current_setting
-    setting.assign_attributes(raw_attributes)
-
-    if setting.save
-      render json: setting.serializable_hash, status: :ok
-    else
-      render_validation_error setting
-    end
-  end
-
-  private
-
-  def current_setting
-    Setting.find_or_create_by!(user: current_user) do |setting|
-      setting.assign_attributes(Setting.defaults)
-    end
-  rescue ActiveRecord::RecordNotUnique
-    Setting.find_by!(user: current_user)
-  end
-
-  def editable_raw_attributes
-    request.request_parameters.slice(*Setting::EDITABLE_ATTRIBUTES)
-  end
-
-  def validate_raw_attributes raw_attributes
-    raw_attributes.each_with_object({ }) do |(key, value), errors|
-      next if value_matches_type?(key, value)
-
-      errors[key.to_sym] = ['値の型が不正です．']
-    end
-  end
-
-  def value_matches_type? key, value
-    case Setting::TYPE_BY_ATTRIBUTE.fetch(key)
-    when :string
-      value.is_a?(String)
-    when :integer
-      value.is_a?(Integer)
-    when :boolean
-      value == true || value == false
-    else
-      false
-    end
-  end
-end

backend/app/controllers/user_theme_slots_controller.rb

@@ -1,38 +0,0 @@
-class UserThemeSlotsController < ApplicationController
-  wrap_parameters false
-
-  def index
-    return head :unauthorized unless current_user
-
-    render json: current_user
-                 .theme_slots
-                 .order(:base_theme, :slot_no)
-                 .map { |slot| slot.serializable_hash }
-  end
-
-  def update
-    return head :unauthorized unless current_user
-
-    base_theme = params[:base_theme].to_s
-    slot_no = params[:slot_no].to_i
-    tokens = params[:tokens]
-
-    unless UserThemeSlot::BASE_THEMES.include?(base_theme)
-      return render_validation_error fields: { base_theme: ['値が不正です．'] }
-    end
-    unless UserThemeSlot::SLOT_NOS.include?(slot_no)
-      return render_validation_error fields: { slot_no: ['値が不正です．'] }
-    end
-    unless tokens.is_a?(ActionController::Parameters) || tokens.is_a?(Hash)
-      return render_validation_error fields: { tokens: ['JSON object で指定してください．'] }
-    end
-
-    slot = UserThemeSlot.find_or_initialize_by(user: current_user,
-                                               base_theme:,
-                                               slot_no:)
-    slot.tokens = tokens.is_a?(ActionController::Parameters) ? tokens.to_unsafe_h : tokens
-    slot.save!
-
-    render json: slot.serializable_hash, status: :ok
-  end
-end

backend/app/controllers/users_controller.rb

@@ -1,6 +1,9 @@
 class UsersController < ApplicationController
   def create
+    return head :unprocessable_entity if request.remote_ip.blank?
+
     user = nil
+
     User.transaction do
       user = User.create!(inheritance_code: SecureRandom.uuid, role: :guest)
       attach_ip_address!(user)
@@ -14,7 +17,8 @@ class UsersController < ApplicationController
   def verify
     user = User.find_by(inheritance_code: params[:code])
     return render json: { valid: false } unless user
-    return head :forbidden if user.banned?
+
+    return head :unprocessable_entity if request.remote_ip.blank?
 
     attach_ip_address!(user)
 
@@ -42,12 +46,12 @@ class UsersController < ApplicationController
     return head :unauthorized if user&.id != params[:id].to_i
 
     name = params[:name]
-    return render_unprocessable_entity('名前は必須です．', field: :name) if name.blank?
+    return head :bad_request if name.blank?
 
     if user.update(name:)
       render json: user.slice(:id, :name, :inheritance_code, :role), status: :ok
     else
-      render_validation_error user
+      render json: user.errors, status: :unprocessable_entity
     end
   end
 

backend/app/controllers/wiki_pages_controller.rb

@@ -4,18 +4,17 @@ class WikiPagesController < ApplicationController
   def index
     title = params[:title].to_s.strip
     if title.blank?
-      return render json: WikiPageRepr.base(
-          WikiPage.joins(:tag_name).includes(tag_name: :tag))
+      return render json: WikiPageRepr.base(WikiPage.joins(:tag_name).includes(:tag_name))
     end
 
-    q = WikiPage.joins(:tag_name).includes(tag_name: :tag)
+    q = WikiPage.joins(:tag_name).includes(:tag_name)
         .where('tag_names.name LIKE ?', "%#{ WikiPage.sanitize_sql_like(title) }%")
     render json: WikiPageRepr.base(q.limit(20))
   end
 
   def show
     page = WikiPage.joins(:tag_name)
-                   .includes(tag_name: :tag)
+                   .includes(:tag_name)
                    .find_by(id: params[:id])
     render_wiki_page_or_404 page
   end
@@ -23,7 +22,7 @@ class WikiPagesController < ApplicationController
   def show_by_title
     title = params[:title].to_s.strip
     page = WikiPage.joins(:tag_name)
-                   .includes(tag_name: :tag)
+                   .includes(:tag_name)
                    .find_by(tag_name: { name: title })
     render_wiki_page_or_404 page
   end
@@ -47,17 +46,17 @@ class WikiPagesController < ApplicationController
 
   def diff
     id = params[:id]
-    return render_bad_request('id は必須です．') if id.blank?
+    return head :bad_request if id.blank?
 
     from = params[:from].presence
     to = params[:to].presence
 
-    page = WikiPage.joins(:tag_name).includes(tag_name: :tag).find(id)
+    page = WikiPage.joins(:tag_name).includes(:tag_name).find(id)
 
     from_rev = from && page.wiki_revisions.find(from)
     to_rev = to ? page.wiki_revisions.find(to) : page.current_revision
     if ((from_rev && !(from_rev.content?)) || !(to_rev&.content?))
-      return render_unprocessable_entity('差分を表示できない版です．')
+      return head :unprocessable_entity
     end
 
     diffs = Diff::LCS.sdiff(from_rev&.body&.lines || [], to_rev.body.lines)
@@ -77,7 +76,6 @@ class WikiPagesController < ApplicationController
 
     render json: { wiki_page_id:      page.id,
                    title:             page.title,
-                   deprecated_at:     page.deprecated_at,
                    older_revision_id: from_rev&.id,
                    newer_revision_id: to_rev.id,
                    diff:              diff_json }
@@ -91,8 +89,7 @@ class WikiPagesController < ApplicationController
     body = params[:body].to_s
     message = params[:message].presence
 
-    return render_unprocessable_entity('タイトルは必須です．', field: :title) if title.blank?
-    return render_unprocessable_entity('本文は必須です．', field: :body) if body.blank?
+    return head :unprocessable_entity if title.blank? || body.blank?
 
     tag_name = TagName.find_undiscard_or_create_by!(name: title)
 
@@ -104,10 +101,8 @@ class WikiPagesController < ApplicationController
             message:)
 
     render json: WikiPageRepr.base(page), status: :created
-  rescue ActiveRecord::RecordInvalid => e
-    render_validation_error e.record
-  rescue ActiveRecord::RecordNotUnique
-    render_record_not_unique
+  rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique
+    head :unprocessable_entity
   end
 
   def update
@@ -117,8 +112,7 @@ class WikiPagesController < ApplicationController
     title = params[:title]&.strip
     body = params[:body].to_s
 
-    return render_unprocessable_entity('タイトルは必須です．', field: :title) if title.blank?
-    return render_unprocessable_entity('本文は必須です．', field: :body) if body.blank?
+    return head :unprocessable_entity if title.blank? || body.blank?
 
     page = WikiPage.find(params[:id])
     base_revision_id = params[:base_revision_id].presence
@@ -159,7 +153,7 @@ class WikiPagesController < ApplicationController
   def changes
     id = params[:id].presence
     q = WikiRevision.joins(wiki_page: :tag_name)
-                    .includes(:created_user, wiki_page: { tag_name: :tag })
+                    .includes(:created_user, wiki_page: :tag_name)
                     .order(id: :desc)
     q = q.where(wiki_page_id: id) if id
 
@@ -167,9 +161,7 @@ class WikiPagesController < ApplicationController
       { revision_id:  rev.id,
         pred:         rev.base_revision_id,
         succ:         nil,
-        wiki_page:    { id: rev.wiki_page_id,
-                        title: rev.wiki_page.title,
-                        deprecated_at: rev.wiki_page.deprecated_at },
+        wiki_page:    { id: rev.wiki_page_id, title: rev.wiki_page.title },
         user:         rev.created_user && { id: rev.created_user.id, name: rev.created_user.name },
         kind:         rev.kind,
         message:      rev.message,

backend/app/models/gekanator_ai_run.rb

@@ -1,21 +0,0 @@
-class GekanatorAiRun < ApplicationRecord
-  STATUSES = ['pending', 'running', 'succeeded', 'failed', 'blocked_budget'].freeze
-
-  belongs_to :gekanator_question_suggestion
-
-  validates :model, presence: true, length: { maximum: 255 }
-  validates :status, presence: true, inclusion: { in: STATUSES }
-  validates :input_tokens,
-            presence: true,
-            numericality: { only_integer: true, greater_than_or_equal_to: 0 }
-  validates :output_tokens,
-            presence: true,
-            numericality: { only_integer: true, greater_than_or_equal_to: 0 }
-  validates :estimated_cost_jpy,
-            presence: true,
-            numericality: { greater_than_or_equal_to: 0 }
-
-  scope :this_month, lambda {
-    where(created_at: Time.current.beginning_of_month..Time.current.end_of_month)
-  }
-end

backend/app/models/gekanator_game.rb

@@ -1,15 +0,0 @@
-class GekanatorGame < ApplicationRecord
-  belongs_to :user
-  belongs_to :guessed_post, class_name: 'Post'
-  belongs_to :correct_post, class_name: 'Post'
-  has_many :question_suggestions,
-           class_name: 'GekanatorQuestionSuggestion',
-           dependent: :delete_all
-  has_many :question_examples,
-           class_name: 'GekanatorQuestionExample',
-           dependent: :delete_all
-
-  validates :answers, presence: true
-  validates :question_count, numericality: { greater_than_or_equal_to: 0 }
-  validates :won, inclusion: { in: [true, false] }
-end

backend/app/models/gekanator_question.rb

@@ -1,23 +0,0 @@
-class GekanatorQuestion < ApplicationRecord
-  KINDS = ['tag', 'source', 'title', 'original_date', 'post_similarity'].freeze
-  SOURCES = ['user_suggested', 'ai_generated', 'admin_curated'].freeze
-  STATUSES = ['pending', 'accepted', 'rejected', 'disabled'].freeze
-
-  belongs_to :gekanator_question_suggestion, optional: true
-  belongs_to :created_by, class_name: 'User', optional: true
-  has_many :gekanator_question_examples, dependent: :delete_all
-
-  validates :kind, presence: true, inclusion: { in: KINDS }
-  validates :source, presence: true, inclusion: { in: SOURCES }
-  validates :status, presence: true, inclusion: { in: STATUSES }
-  validates :text, presence: true, length: { maximum: 1000 }
-  validates :condition, presence: true
-  validates :priority_weight,
-            presence: true,
-            numericality: {
-              greater_than: 0,
-              less_than_or_equal_to: 3
-            }
-
-  scope :accepted, -> { where(status: 'accepted') }
-end

backend/app/models/gekanator_question_example.rb

@@ -1,97 +0,0 @@
-class GekanatorQuestionExample < ApplicationRecord
-  ANSWERS = GekanatorQuestionSuggestion::ANSWERS
-  NON_UNKNOWN_ANSWERS = ANSWERS - ['unknown']
-  SOURCES = ['initial_suggestion', 'post_game_answer', 'post_game_extra'].freeze
-
-  belongs_to :gekanator_question
-  belongs_to :post
-  belongs_to :user
-  belongs_to :gekanator_game, optional: true
-
-  validates :answer, presence: true, inclusion: { in: ANSWERS }
-  validates :answer_counts, presence: true
-  validates :sample_count,
-            presence: true,
-            numericality: {
-              only_integer: true,
-              greater_than: 0
-            }
-  validates :source, presence: true, inclusion: { in: SOURCES }
-  validates :weight,
-            presence: true,
-            numericality: {
-              greater_than: 0
-            }
-
-  before_validation :normalize_learning_state
-
-  def record_answer!(answer:, source:, gekanator_game: nil)
-    answer = answer.to_s
-    raise ArgumentError, 'invalid answer' unless ANSWERS.include?(answer)
-
-    counts = normalized_answer_counts
-    counts[answer] += 1
-
-    self.answer_counts = counts
-    self.sample_count = counts.values.sum
-    self.gekanator_game = gekanator_game if gekanator_game.present?
-    self.source = source
-
-    apply_aggregated_answer!(preferred_answer: answer)
-    self
-  end
-
-  private
-
-  def normalize_learning_state
-    counts = normalized_answer_counts
-
-    if counts.values.sum.zero? && answer.present?
-      counts[answer] = 1
-    end
-
-    self.answer_counts = counts
-    self.sample_count = counts.values.sum
-
-    apply_aggregated_answer!
-  end
-
-  def apply_aggregated_answer!(preferred_answer: nil)
-    counts = normalized_answer_counts
-    known_counts = counts.slice(*NON_UNKNOWN_ANSWERS)
-    known_total = known_counts.values.sum
-
-    if known_total.zero?
-      self.answer = 'unknown'
-      self.weight = 0.1
-      return
-    else
-      max_count = known_counts.values.max
-      candidates = known_counts.select { |_answer, count| count == max_count }.keys
-      self.answer =
-          if preferred_answer.present? && candidates.include?(preferred_answer)
-            preferred_answer
-          elsif answer.present? && candidates.include?(answer)
-            answer
-          else
-            candidates.first
-          end
-    end
-
-    consensus = max_count.to_f / known_total
-    self.weight = Math.sqrt(known_total) * consensus
-  end
-
-  def normalized_answer_counts
-    base = ANSWERS.index_with(0)
-
-    answer_counts.to_h.each do |key, value|
-      answer_key = key.to_s
-      next unless ANSWERS.include?(answer_key)
-
-      base[answer_key] = value.to_i
-    end
-
-    base
-  end
-end

backend/app/models/gekanator_question_suggestion.rb

@@ -1,12 +0,0 @@
-class GekanatorQuestionSuggestion < ApplicationRecord
-  ANSWERS = ['yes', 'no', 'partial', 'probably_no', 'unknown'].freeze
-
-  belongs_to :gekanator_game
-  belongs_to :user
-  has_many :gekanator_questions, dependent: :nullify
-  has_many :gekanator_ai_runs, dependent: :destroy
-
-  validates :question_text, presence: true, length: { maximum: 1000 }
-  validates :answer, presence: true, inclusion: { in: ANSWERS }
-  validates :processed, inclusion: { in: [true, false] }
-end

backend/app/models/ip_address.rb

@@ -1,10 +1,7 @@
 class IpAddress < ApplicationRecord
   validates :ip_address, presence: true, length: { maximum: 16 }
+  validates :banned, inclusion: { in: [true, false] }
 
   has_many :user_ips, dependent: :destroy
   has_many :users, through: :user_ips
-
-  def banned? = banned_at.present?
-  def ban! = banned? || update!(banned_at: Time.current)
-  def unban! = update!(banned_at: nil)
 end

backend/app/models/material.rb

@@ -1,9 +1,6 @@
 class Material < ApplicationRecord
   include MyDiscard
 
-  SOURCE_KINDS = ['uri', 'google_drive_path', 'google_drive_file',
-                  'legacy_drive_path'].freeze
-
   default_scope -> { kept }
 
   belongs_to :parent, class_name: 'Material', optional: true
@@ -13,18 +10,9 @@ class Material < ApplicationRecord
   belongs_to :created_by_user, class_name: 'User', optional: true
   belongs_to :updated_by_user, class_name: 'User', optional: true
 
-  has_many :material_versions, dependent: :destroy
-  has_many :material_export_items, dependent: :destroy
-
   has_one_attached :file, dependent: :purge
-  has_one_attached :thumbnail, dependent: :purge
 
-  before_validation :assign_normalized_source_key
-
-  validates :tag_id, uniqueness: true, allow_nil: true
-  validates :source_kind,
-            inclusion: { in: SOURCE_KINDS },
-            allow_blank: true
+  validates :tag_id, presence: true, uniqueness: true
 
   validate :file_must_be_attached
   validate :tag_must_be_material_category
@@ -35,37 +23,8 @@ class Material < ApplicationRecord
     file.blob.content_type
   end
 
-  def file_byte_size
-    return nil unless file&.attached?
-
-    file.blob.byte_size
-  end
-
-  def file_filename
-    return nil unless file&.attached?
-
-    file.blob.filename.to_s
-  end
-
-  def snapshot_export_paths
-    material_export_items.order(:profile).pluck(:profile, :export_path).to_h
-  end
-
   private
 
-  def assign_normalized_source_key
-    if source_kind.blank?
-      self.normalized_source_key = nil
-      return
-    end
-
-    self.normalized_source_key =
-        MaterialSyncSuppression.normalize_source_key(source_kind:,
-                                                     source_uri:,
-                                                     drive_path: source_path,
-                                                     drive_file_id: source_file_id)
-  end
-
   def file_must_be_attached
     return if url.present? || file.attached?
 

backend/app/models/material_export_item.rb

@@ -1,48 +0,0 @@
-class MaterialExportItem < ApplicationRecord
-  VALID_PROFILES = ['legacy_drive'].freeze
-
-  belongs_to :material
-  belongs_to :created_by_user, class_name: 'User', optional: true
-
-  validates :profile, presence: true, inclusion: { in: VALID_PROFILES }
-  validates :export_path, presence: true, uniqueness: { scope: :profile }
-  validates :material_id, uniqueness: { scope: :profile }
-  validate :export_path_must_be_relative_safe_path
-
-  scope :enabled, -> { where(enabled: true) }
-
-  private
-
-  def export_path_must_be_relative_safe_path
-    return if export_path.blank?
-
-    if export_path.start_with?('/')
-      errors.add(:export_path, '絶対パスは使へません．')
-    end
-
-    if export_path.match?(/\A[A-Za-z]:\//)
-      errors.add(:export_path, '絶対パスは使へません．')
-    end
-
-    if export_path.include?('\\')
-      errors.add(:export_path, '/ 区切りで指定してください．')
-    end
-
-    if export_path.include?("\0")
-      errors.add(:export_path, 'NUL は使へません．')
-    end
-
-    parts = export_path.split('/')
-    if export_path.include?('//')
-      errors.add(:export_path, '空の path segment は使へません．')
-    end
-
-    if parts.any? { |part| part.in?(['.', '..']) }
-      errors.add(:export_path, '.. は使へません．')
-    end
-
-    if export_path.end_with?('/')
-      errors.add(:export_path, 'directory path は使へません．')
-    end
-  end
-end

backend/app/models/material_import_block.rb

@@ -1,29 +0,0 @@
-class MaterialImportBlock < ApplicationRecord
-  MATCH_KINDS = ['sha256', 'exact_path', 'path_prefix', 'manual'].freeze
-  REASONS = [
-    'copyright_high_risk',
-    'copyright_takedown',
-    'adult_or_sensitive',
-    'personal_information',
-    'malware_or_dangerous_file',
-    'duplicate_or_low_quality',
-    'source_owner_request',
-    'other'
-  ].freeze
-
-  belongs_to :created_by_user, class_name: 'User', optional: true
-
-  validates :match_kind, presence: true, inclusion: { in: MATCH_KINDS }
-  validates :reason, presence: true, inclusion: { in: REASONS }
-  validates :sha256, length: { is: 64 }, allow_blank: true
-  validate :match_value_must_be_present
-
-  private
-
-  def match_value_must_be_present
-    return if match_kind == 'manual'
-    return if sha256.present? || external_path_pattern.present?
-
-    errors.add(:base, 'sha256 または external_path_pattern は必須です．')
-  end
-end

backend/app/models/material_sync_source.rb

@@ -1,45 +0,0 @@
-class MaterialSyncSource < ApplicationRecord
-  SOURCE_KINDS = ['uri', 'google_drive_path', 'google_drive_file', 'legacy_drive_path'].freeze
-
-  belongs_to :created_by_user, class_name: 'User', optional: true
-  belongs_to :updated_by_user, class_name: 'User', optional: true
-
-  validates :name, presence: true
-  validates :source_kind,
-            presence: true,
-            inclusion: { in: SOURCE_KINDS }
-  validates :profile, presence: true, inclusion: { in: MaterialExportItem::VALID_PROFILES }
-  validate :source_value_must_be_present
-
-  scope :enabled, -> { where(enabled: true) }
-
-  def normalized_source_key
-    MaterialSyncSuppression.normalize_source_key(source_kind:,
-                                                 source_uri:,
-                                                 source_path:,
-                                                 source_file_id:)
-  end
-
-  private
-
-  def source_value_must_be_present
-    return if source_value_present?
-
-    errors.add(:base, '同期元を指定してください．')
-  end
-
-  def source_value_present?
-    case source_kind
-    when 'uri'
-      source_uri.present?
-    when 'google_drive_file'
-      source_file_id.present? || source_uri.present?
-    when 'google_drive_path'
-      source_file_id.present? || source_uri.present?
-    when 'legacy_drive_path'
-      source_path.present?
-    else
-      normalized_source_key.present?
-    end
-  end
-end

backend/app/models/material_sync_suppression.rb

@@ -1,105 +0,0 @@
-class MaterialSyncSuppression < ApplicationRecord
-  SOURCE_KINDS = [
-    'uri',
-    'google_drive_path',
-    'google_drive_path_prefix',
-    'google_drive_file',
-    'legacy_drive_path',
-    'legacy_drive_path_prefix'
-  ].freeze
-
-  REASONS = [
-    'copyright_high_risk',
-    'copyright_takedown',
-    'adult_or_sensitive',
-    'personal_information',
-    'malware_or_dangerous_file',
-    'duplicate_or_low_quality',
-    'source_owner_request',
-    'other'
-  ].freeze
-
-  belongs_to :created_by_user, class_name: 'User', optional: true
-
-  before_validation :assign_normalized_source_key
-
-  validates :source_kind, presence: true, inclusion: { in: SOURCE_KINDS }
-  validates :reason, presence: true, inclusion: { in: REASONS }
-  validates :normalized_source_key, presence: true, uniqueness: true
-  validate :source_value_must_be_present
-  validate :drive_path_must_be_safe_relative_path
-
-  def self.normalize_source_key source_kind:,
-                                source_uri: nil,
-                                drive_path: nil,
-                                drive_file_id: nil,
-                                source_path: nil,
-                                source_file_id: nil
-    kind = source_kind.to_s
-    value =
-        case kind
-        when 'uri'
-          source_uri.to_s.strip
-        when 'google_drive_path', 'google_drive_path_prefix',
-             'legacy_drive_path', 'legacy_drive_path_prefix'
-          (source_path || drive_path).to_s.strip.gsub(%r{/+}, '/')
-        when 'google_drive_file'
-          (source_file_id || drive_file_id).to_s.strip
-        else
-          ''
-        end
-
-    return nil if kind.blank? || value.blank?
-
-    "#{ kind }:#{ value }"
-  end
-
-  private
-
-  def assign_normalized_source_key
-    normalize_path_fields!
-    self.normalized_source_key =
-        self.class.normalize_source_key(source_kind:,
-                                        source_uri:,
-                                        drive_path:,
-                                        drive_file_id:)
-  end
-
-  def source_value_must_be_present
-    return if normalized_source_key.present?
-
-    errors.add(:base, '同期元を指定してください．')
-  end
-
-  def drive_path_must_be_safe_relative_path
-    return unless source_kind.in?(
-        ['google_drive_path', 'google_drive_path_prefix',
-         'legacy_drive_path', 'legacy_drive_path_prefix'])
-
-    value = drive_path.to_s
-    return if value.blank?
-
-    if value.start_with?('/') || value.match?(/\A[A-Za-z]:\//)
-      errors.add(:drive_path, '相対 path を指定してください．')
-    end
-    if value.start_with?('My Drive/', 'マイドライブ/')
-      errors.add(:drive_path, '同期元フォルダからの相対 path を指定してください．')
-    end
-    errors.add(:drive_path, 'NUL は使へません．') if value.include?("\0")
-    errors.add(:drive_path, '連続スラッシュは使へません．') if value.include?('//')
-    errors.add(:drive_path, '末尾スラッシュは使へません．') if value.end_with?('/')
-
-    parts = value.split('/')
-    if parts.any? { |part| part.in?(['.', '..']) }
-      errors.add(:drive_path, '. や .. は使へません．')
-    end
-  end
-
-  def normalize_path_fields!
-    return unless source_kind.in?(
-        ['google_drive_path', 'google_drive_path_prefix',
-         'legacy_drive_path', 'legacy_drive_path_prefix'])
-
-    self.drive_path = drive_path.to_s.tr('\\', '/').strip.presence
-  end
-end

backend/app/models/material_version.rb

@@ -1,17 +0,0 @@
-class MaterialVersion < ApplicationRecord
-  EVENT_TYPE_MAP = { create: 'create',
-                     update: 'update',
-                     discard: 'discard',
-                     restore: 'restore' }.freeze
-
-  include VersionRecord
-
-  belongs_to :material
-  belongs_to :tag, optional: true
-  belongs_to :parent, class_name: 'Material', optional: true
-  belongs_to :updated_by_user, class_name: 'User', optional: true
-
-  def export_paths_hash
-    export_paths_json || {}
-  end
-end

backend/app/models/post.rb

@@ -1,56 +1,5 @@
 class Post < ApplicationRecord
-  require 'date'
   require 'mini_magick'
-  require 'nokogiri'
-  require 'stringio'
-  require 'timeout'
-
-  class RemoteThumbnailFetchFailed < StandardError; end
-
-  ORIGINAL_CREATED_INVALID_MESSAGE = 'オリジナルの作成日時の形式が不正です．'.freeze
-  ORIGINAL_CREATED_MINUTE_PRECISION_MESSAGE =
-      'オリジナルの作成日時は分単位で入力してください．'.freeze
-  ORIGINAL_CREATED_ORDER_MESSAGE = 'オリジナルの作成日時の順番がをかしぃです．'.freeze
-  ORIGINAL_CREATED_MINIMUM_RANGE_MESSAGE =
-      'オリジナルの作成日時の範囲は1分以上必要です．'.freeze
-  REMOTE_SVG_CONTENT_TYPE = 'image/svg+xml'.freeze
-  MAX_SVG_DIMENSION = 4_096
-  MAX_SVG_PIXELS = 16_777_216
-  THUMBNAIL_PROCESS_TIMEOUT = 5.seconds
-  def self.resized_thumbnail_attachment(upload, content_type: nil)
-    upload.rewind
-    bytes = upload.read
-    blob = Timeout.timeout(THUMBNAIL_PROCESS_TIMEOUT) do
-      image = image_for_thumbnail_upload(bytes, content_type:)
-      image.auto_orient
-      image.resize '180x180'
-      image.format 'jpg'
-      image.to_blob
-    end
-
-    { io: StringIO.new(blob),
-      filename: 'resized_thumbnail.jpg',
-      content_type: 'image/jpeg' }
-  rescue Timeout::Error
-    raise MiniMagick::Error, 'サムネイル画像の変換に失敗しました．'
-  ensure
-    upload.rewind
-  end
-
-  def self.remote_thumbnail_attachment(raw_url)
-    response = Preview::ThumbnailFetcher.fetch_image_response(raw_url)
-    resized_thumbnail_attachment(
-        StringIO.new(response.body),
-        content_type: response.content_type)
-  rescue Preview::UrlSafety::UnsafeUrl,
-         Preview::ThumbnailFetcher::GenerationFailed,
-         Preview::HttpFetcher::FetchFailed,
-         Preview::HttpFetcher::FetchTimeout,
-         Preview::HttpFetcher::ResponseTooLarge,
-         Timeout::Error,
-         MiniMagick::Error => e
-    raise RemoteThumbnailFetchFailed, e.message
-  end
 
   belongs_to :uploaded_user, class_name: 'User', optional: true
 
@@ -58,23 +7,10 @@ class Post < ApplicationRecord
   has_many :active_post_tags, -> { kept }, class_name: 'PostTag', inverse_of: :post
   has_many :post_tags_with_discarded, -> { with_discarded }, class_name: 'PostTag'
   has_many :tags, through: :active_post_tags
-  has_many :active_tags, -> { where(tags: { deprecated_at: nil }) },
-           through: :active_post_tags, source: :tag
 
   has_many :user_post_views, dependent: :delete_all
   has_many :post_similarities, dependent: :delete_all
   has_many :post_versions
-  has_many :gekanator_guessed_games,
-           class_name: 'GekanatorGame',
-           foreign_key: :guessed_post_id,
-           dependent: :delete_all,
-           inverse_of: :guessed_post
-  has_many :gekanator_correct_games,
-           class_name: 'GekanatorGame',
-           foreign_key: :correct_post_id,
-           dependent: :delete_all,
-           inverse_of: :correct_post
-  has_many :gekanator_question_examples, dependent: :delete_all
 
   has_many :parent_post_implications,
            class_name: 'PostImplication',
@@ -92,12 +28,9 @@ class Post < ApplicationRecord
 
   has_one_attached :thumbnail
 
-  attribute :version_no, :integer, default: 1
+  before_validation :normalise_url
 
-  before_validation :normalise_url, if: :will_save_change_to_url?
-
-  validates :url, presence: true, uniqueness: true, length: { maximum: 768 }
-  validates :video_ms, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
+  validates :url, presence: true, uniqueness: true
 
   validate :validate_original_created_range
   validate :url_must_be_http_url
@@ -121,46 +54,7 @@ class Post < ApplicationRecord
     super(options).merge(thumbnail: nil)
   end
 
-  def snapshot_tag_names
-    post_tags
-        .kept
-        .joins(tag: :tag_name)
-        .includes(:sections, tag: :tag_name)
-        .order('tag_names.name')
-        .map do |post_tag|
-      name = post_tag.tag.tag_name.name
-      sections = post_tag.sections.sort_by(&:begin_ms)
-
-      next name if sections.empty?
-
-      "#{ name }#{ sections.map { Post.section_literal(_1) }.join }"
-    end
-  end
-
-  def self.section_literal section
-    "[#{ Post.ms_to_time(section.begin_ms) }-#{ section.end_ms ? Post.ms_to_time(section.end_ms) : '' }]"
-  end
-
-  def self.ms_to_time ms
-    total_s = ms / 1_000
-    s = total_s % 60
-    min = (total_s / 60) % 60
-    h = total_s / 3_600
-    remainder_ms = ms % 1_000
-
-    base =
-        if h.positive?
-          '%d:%02d:%02d' % [h, min, s]
-        else
-          '%d:%02d' % [min, s]
-        end
-
-    if remainder_ms.positive?
-      "#{ base }.#{ remainder_ms.to_s.rjust(3, '0') }"
-    else
-      base
-    end
-  end
+  def snapshot_tag_names = tags.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
 
   def snapshot_parent_post_ids = parents.order(:id).pluck(:id)
 
@@ -178,29 +72,27 @@ class Post < ApplicationRecord
   def resized_thumbnail!
     return unless thumbnail.attached?
 
-    thumbnail.attach(self.class.resized_thumbnail_attachment(StringIO.new(thumbnail.download)))
-  end
-
-  def attach_thumbnail_from_url! raw_url
-    thumbnail.attach(self.class.remote_thumbnail_attachment(raw_url))
+    image = MiniMagick::Image.read(thumbnail.download)
+    image.resize '180x180'
+    thumbnail.purge
+    thumbnail.attach(io:            File.open(image.path),
+                     filename:      'resized_thumbnail.jpg',
+                     content_type:  'image/jpeg')
   end
 
   private
 
   def validate_original_created_range
-    return if skip_original_created_validation?
+    f = original_created_from
+    b = original_created_before
+    return if f.blank? || b.blank?
 
-    f = parse_original_created_value(:original_created_from)
-    b = parse_original_created_value(:original_created_before)
-    return if f.nil? || b.nil?
+    f = Time.zone.parse(f) if String === f
+    b = Time.zone.parse(b) if String === b
+    return if !(f) || !(b)
 
-    if b <= f
-      errors.add :original_created_at, ORIGINAL_CREATED_ORDER_MESSAGE
-      return
-    end
-
-    if b - f < 1.minute
-      errors.add :original_created_at, ORIGINAL_CREATED_MINIMUM_RANGE_MESSAGE
+    if f >= b
+      errors.add :original_created_before, 'オリジナルの作成日時の順番がをかしぃです．'
     end
   end
 
@@ -221,295 +113,15 @@ class Post < ApplicationRecord
   def normalise_url
     return if url.blank?
 
-    self.url = PostUrlNormaliser.normalise(url) || url.strip
-  end
+    self.url = url.strip
 
-  def self.image_for_thumbnail_upload(bytes, content_type: nil)
-    if svg_content_type?(content_type) || svg_document_bytes?(bytes)
-      return decode_svg_thumbnail(bytes)
-    end
+    u = URI.parse(url)
+    return unless u in URI::HTTP
 
-    raise MiniMagick::Error, 'サムネイル画像の形式が不正です．' unless raster_thumbnail_bytes?(bytes)
-
-    decode_raster_thumbnail(bytes)
-  end
-
-  def self.raster_thumbnail_bytes?(bytes)
-    raster_thumbnail_format(bytes).present?
-  end
-
-  def self.remote_thumbnail_image_bytes?(bytes, content_type: nil)
-    return true if svg_content_type?(content_type) || svg_document_bytes?(bytes)
-
-    raster_thumbnail_bytes?(bytes)
-  end
-
-  def self.svg_content_type?(content_type)
-    content_type.to_s.split(';', 2).first.to_s.downcase.strip == REMOTE_SVG_CONTENT_TYPE
-  end
-
-  def self.svg_document_bytes?(bytes)
-    document = Nokogiri::XML(
-        bytes,
-        nil,
-        nil,
-        Nokogiri::XML::ParseOptions::STRICT |
-        Nokogiri::XML::ParseOptions::NONET)
-    document.root&.name == 'svg'
-  rescue Nokogiri::XML::SyntaxError
-    false
-  end
-
-  def self.decode_raster_thumbnail(bytes)
-    MiniMagick::Image.read(bytes)
-  end
-
-  def self.decode_svg_thumbnail(bytes)
-    MiniMagick::Image.read(sanitised_svg_bytes(bytes))
-  end
-
-  def self.raster_thumbnail_format(bytes)
-    binary = bytes.to_s.b
-    return 'jpeg' if binary.start_with?("\xFF\xD8\xFF".b)
-    return 'png' if binary.start_with?("\x89PNG\r\n\x1A\n".b)
-    return 'gif' if binary.start_with?('GIF87a'.b) || binary.start_with?('GIF89a'.b)
-    return 'webp' if binary.bytesize >= 12 &&
-                     binary.start_with?('RIFF'.b) &&
-                     binary.byteslice(8, 4) == 'WEBP'
-
-    nil
-  end
-
-  def self.sanitised_svg_bytes(bytes)
-    parse_options =
-        Nokogiri::XML::ParseOptions::STRICT |
-        Nokogiri::XML::ParseOptions::NONET
-    document = Nokogiri::XML(
-        bytes,
-        nil,
-        nil,
-        parse_options)
-    root = document.root
-    raise MiniMagick::Error, 'SVG が不正です．' if root == nil || root.name != 'svg'
-    raise MiniMagick::Error, 'SVG が不正です．' if document.internal_subset != nil
-    raise MiniMagick::Error, 'SVG が不正です．' if svg_uses_disallowed_features?(document)
-
-    width, height = svg_dimensions(root)
-    raise MiniMagick::Error, 'SVG が大きすぎます．' if width == nil || height == nil
-    if width > MAX_SVG_DIMENSION || height > MAX_SVG_DIMENSION || width * height > MAX_SVG_PIXELS
-      raise MiniMagick::Error, 'SVG が大きすぎます．'
-    end
-
-    document.to_xml
-  rescue Nokogiri::XML::SyntaxError
-    raise MiniMagick::Error, 'SVG が不正です．'
-  end
-
-  def self.svg_uses_disallowed_features?(document)
-    document.traverse.any? do |node|
-      next false unless node.element?
-
-      name = node.name.to_s.downcase
-      next true if name == 'script' || name == 'foreignobject'
-      next style_contains_disallowed_urls?(node.text.to_s) if name == 'style'
-
-      node.attribute_nodes.any? do |attribute|
-        attribute_name = attribute.name.to_s.downcase
-        attribute_value = attribute.value.to_s
-        attribute_name.start_with?('on') ||
-            external_svg_reference?(attribute_name, attribute_value)
-      end
-    end
-  end
-
-  def self.external_svg_reference?(attribute_name, attribute_value)
-    return external_svg_url?(attribute_value) if ['href', 'xlink:href', 'src'].include?(attribute_name)
-    return style_contains_disallowed_urls?(attribute_value) if attribute_name == 'style'
-    return svg_url_function_disallowed?(attribute_value) if attribute_value.match?(/url\s*\(/i)
-
-    false
-  end
-
-  def self.external_svg_url?(value)
-    stripped = value.to_s.strip
-    return false if stripped.blank? || stripped.start_with?('#')
-
-    true
-  end
-
-  def self.style_contains_disallowed_urls?(value)
-    text = value.to_s
-    text.match?(/@import/i) || svg_url_function_disallowed?(text)
-  end
-
-  def self.svg_url_function_disallowed?(value)
-    value.to_s.scan(/url\s*\(([^)]*)\)/i).flatten.any? do |entry|
-      reference = entry.to_s.strip.delete_prefix("'").delete_prefix('"').delete_suffix("'").delete_suffix('"')
-      reference.present? && !(reference.start_with?('#'))
-    end
-  end
-
-  def self.svg_dimensions(root)
-    width = svg_length_to_pixels(root['width'])
-    height = svg_length_to_pixels(root['height'])
-    return [width, height] if width && height
-
-    view_box = root['viewBox'].to_s.strip.split(/\s+/).map { Float(_1) rescue nil }
-    return [nil, nil] if view_box.length != 4 || view_box.any?(&:nil?)
-    return [nil, nil] unless view_box[2].finite? && view_box[2].positive?
-    return [nil, nil] unless view_box[3].finite? && view_box[3].positive?
-
-    [view_box[2], view_box[3]]
-  end
-
-  def self.svg_length_to_pixels(value)
-    return nil if value.blank?
-
-    matched = /\A([0-9]+(?:\.[0-9]+)?)(px)?\z/i.match(value.to_s.strip)
-    return nil if matched == nil
-
-    pixels = Float(matched[1])
-    return nil unless pixels.finite? && pixels.positive?
-
-    pixels
-  rescue ArgumentError
-    nil
-  end
-
-  private_class_method :image_for_thumbnail_upload,
-                       :svg_content_type?,
-                       :decode_raster_thumbnail,
-                       :decode_svg_thumbnail,
-                       :raster_thumbnail_format,
-                       :sanitised_svg_bytes,
-                       :svg_uses_disallowed_features?,
-                       :external_svg_reference?,
-                       :external_svg_url?,
-                       :style_contains_disallowed_urls?,
-                       :svg_url_function_disallowed?,
-                       :svg_dimensions,
-                       :svg_length_to_pixels
-
-  def parse_original_created_value field
-    raw_value = public_send("#{ field }_before_type_cast")
-    value = public_send(field)
-    return nil if raw_value.blank? && value.blank?
-
-    time =
-        case raw_value
-        when String
-          parse_original_created_string(raw_value)
-        when Time, ActiveSupport::TimeWithZone
-          raw_value.in_time_zone
-        else
-          value&.in_time_zone
-        end
-    if time.nil?
-      errors.add field, ORIGINAL_CREATED_INVALID_MESSAGE
-      return nil
-    end
-    unless minute_precision_time?(time)
-      errors.add field, ORIGINAL_CREATED_MINUTE_PRECISION_MESSAGE
-      return nil
-    end
-    time
-  end
-
-  def parse_original_created_string raw_value
-    value = raw_value.to_s.strip
-    return nil if value.blank?
-
-    match = value.match(/\A(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})\z/)
-    if match
-      year = match[1].to_i
-      month = match[2].to_i
-      day = match[3].to_i
-      hour = match[4].to_i
-      minute = match[5].to_i
-      return nil unless valid_original_created_components?(year, month, day, hour, minute, 0)
-
-      return Time.zone.local(year, month, day, hour, minute)
-    end
-
-    match =
-        value.match(
-            /\A(\d{4})-(\d{2})-(\d{2})T(\d{2}):(\d{2})(?::(\d{2})(?:\.(\d+))?)?(Z|[+-]\d{2}:?\d{2})?\z/)
-    return nil if match.nil?
-
-    year = match[1].to_i
-    month = match[2].to_i
-    day = match[3].to_i
-    hour = match[4].to_i
-    minute = match[5].to_i
-    second = match[6]&.to_i || 0
-    fraction = match[7]
-    offset = match[8]
-    return nil unless valid_original_created_components?(year, month, day, hour, minute, second)
-    return nil if offset.present? && !(valid_original_created_offset?(offset))
-
-    if offset.present?
-      return Time.new(
-          year,
-          month,
-          day,
-          hour,
-          minute,
-          second + Rational(parse_original_created_nanoseconds(fraction), 1_000_000_000),
-          normalise_original_created_offset(offset)).in_time_zone
-    end
-
-    Time.zone.local(
-        year,
-        month,
-        day,
-        hour,
-        minute,
-        second).change(nsec: parse_original_created_nanoseconds(fraction))
-  rescue ArgumentError, TypeError
-    nil
-  end
-
-  def minute_precision_time? value
-    value.sec.zero? && value.nsec.zero?
-  end
-
-  def valid_original_created_components? year, month, day, hour, minute, second
-    return false unless Date.valid_date?(year, month, day)
-    return false unless hour.between?(0, 23)
-    return false unless minute.between?(0, 59)
-    return false unless second.between?(0, 59)
-
-    true
-  end
-
-  def valid_original_created_offset? value
-    match = value.match(/\A([+-])(\d{2}):?(\d{2})\z/)
-    return true if value == 'Z'
-    return false if match.nil?
-
-    hours = match[2].to_i
-    minutes = match[3].to_i
-    hours.between?(0, 23) && minutes.between?(0, 59)
-  end
-
-  def parse_original_created_nanoseconds value
-    return 0 if value.blank?
-
-    digits = value[0, 9].ljust(9, '0')
-    Integer(digits, 10)
-  end
-
-  def normalise_original_created_offset value
-    return '+00:00' if value == 'Z'
-
-    value.match?(/\A[+-]\d{2}:\d{2}\z/) ? value : "#{ value[0, 3] }:#{ value[3, 2] }"
-  end
-
-  def skip_original_created_validation?
-    return false if new_record?
-    return false if will_save_change_to_original_created_from?
-    return false if will_save_change_to_original_created_before?
-
-    true
+    u.host = u.host.downcase if u.host
+    u.path = u.path.sub(/\/\Z/, '') if u.path.present?
+    self.url = u.to_s
+  rescue URI::InvalidURIError
+    ;
   end
 end

backend/app/models/post_tag.rb

@@ -10,12 +10,6 @@ class PostTag < ApplicationRecord
   belongs_to :created_user, class_name: 'User', optional: true
   belongs_to :deleted_user, class_name: 'User', optional: true
 
-  has_many :sections, -> { order(:begin_ms) }, class_name: 'PostTagSection',
-                                               foreign_key: [:post_id, :tag_id],
-                                               primary_key: [:post_id, :tag_id],
-                                               dependent: :delete_all,
-                                               inverse_of: :post_tag
-
   validates :post_id, presence: true
   validates :tag_id, presence: true
   validates :post_id, uniqueness: {

backend/app/models/post_tag_section.rb

@@ -1,20 +0,0 @@
-class PostTagSection < ApplicationRecord
-  self.primary_key = :post_id, :tag_id, :begin_ms
-
-  belongs_to :post
-  belongs_to :tag
-
-  belongs_to :post_tag, -> { kept }, foreign_key: [:post_id, :tag_id],
-                                     primary_key: [:post_id, :tag_id],
-                                     inverse_of: :sections,
-                                     optional: true
-
-  validates :post_id, presence: true
-  validates :tag_id, presence: true
-
-  validates :begin_ms, presence: true,
-                       numericality: { only_integer: true, greater_than_or_equal_to: 0 }
-
-  validates :end_ms, numericality: { only_integer: true, greater_than: :begin_ms },
-                     allow_nil: true
-end

backend/app/models/post_url_sanitisation_rule.rb

@@ -1,163 +0,0 @@
-class PostUrlSanitisationRule < ApplicationRecord
-  include Discard::Model
-
-  class InvalidUrlError < StandardError
-    attr_reader :invalid_rows
-
-    def initialize(invalid_rows)
-      @invalid_rows = invalid_rows
-      ids = invalid_rows.map { _1.fetch(:post_id) }.join(', ')
-      super("post URL sanitisation produced invalid URLs for posts #{ ids }")
-    end
-  end
-
-  class UrlConflictError < StandardError
-    attr_reader :conflicts
-
-    def initialize(conflicts)
-      @conflicts = conflicts
-      urls = conflicts.map { _1.fetch(:url) }.uniq.join(', ')
-      super("post URL sanitisation conflicts detected for #{ urls }")
-    end
-  end
-
-  self.primary_key = :priority
-
-  default_scope -> { kept }
-
-  validates :source_pattern, presence: true, uniqueness: true
-
-  validate :source_pattern_must_be_regexp
-
-  class << self
-    def sanitise(url) = sanitise_with_rules(url, rules)
-
-    def apply!
-      rewrites = nil
-
-      Post.transaction do
-        compiled_rules = rules
-
-        rewrites = Post.order(:id)
-                       .lock('FOR UPDATE')
-                       .pluck(:id, :url)
-                       .map do |post_id, original_url|
-          { post_id:,
-            original_url:,
-            sanitised_url: sanitise_with_rules(original_url, compiled_rules) }
-        end
-
-        invalid_rows = rewrites.filter { invalid_sanitised_url?(_1.fetch(:sanitised_url)) }
-                               .map { { post_id: _1.fetch(:post_id),
-                                        original_url: _1.fetch(:original_url),
-                                        sanitised_url: _1.fetch(:sanitised_url) } }
-        raise InvalidUrlError.new(invalid_rows) if invalid_rows.present?
-
-        conflicts = build_conflicts(rewrites)
-        raise UrlConflictError.new(conflicts) if conflicts.present?
-
-        changed = rewrites.filter { _1.fetch(:original_url) != _1.fetch(:sanitised_url) }
-        return if changed.empty?
-
-        token = SecureRandom.hex(6)
-
-        changed.each do |row|
-          Post.where(id: row.fetch(:post_id))
-              .update_all(url: temporary_url_for(row.fetch(:post_id), token))
-        end
-
-        changed.each do |row|
-          Post.where(id: row.fetch(:post_id))
-              .update_all(url: row.fetch(:sanitised_url))
-        end
-      end
-    rescue ActiveRecord::RecordNotUnique => error
-      conflicts = build_persisted_conflicts(rewrites)
-      raise error if conflicts.empty?
-
-      raise UrlConflictError.new(conflicts), cause: error
-    end
-
-    private
-
-    def rules = kept.order(:priority).map { |r| [Regexp.new(r.source_pattern), r.replacement] }
-
-    def sanitise_with_rules(url, compiled_rules)
-      compiled_rules.reduce(url.dup) do |value, (pattern, replacement)|
-        value.sub(pattern, replacement)
-      end
-    end
-
-    def temporary_url_for(post_id, token) =
-        "https://post-url-sanitising.invalid/#{ token }/#{ post_id }"
-
-    def invalid_sanitised_url?(url)
-      return true if url.blank?
-      return true if url.length > 768
-
-      parsed = URI.parse(url)
-      return true if !(parsed in URI::HTTP)
-      return true if parsed.host.blank?
-
-      false
-    rescue URI::InvalidURIError
-      true
-    end
-
-    def build_conflicts(rewrites)
-      rewrites
-          .group_by { _1.fetch(:sanitised_url).downcase }
-          .values
-          .filter { _1.size > 1 }
-          .flatten
-          .map { { url: _1.fetch(:sanitised_url),
-                   post_id: _1.fetch(:post_id),
-                   original_url: _1.fetch(:original_url) } }
-    end
-
-    def build_persisted_conflicts(rewrites)
-      return [] if rewrites.blank?
-
-      target_rows = rewrites.filter { _1.fetch(:original_url) != _1.fetch(:sanitised_url) }
-      target_keys = target_rows.map { _1.fetch(:sanitised_url).downcase }.uniq
-      return [] if target_keys.empty?
-
-      target_pairs = target_rows.to_h do |row|
-        [row.fetch(:post_id), row.fetch(:sanitised_url).downcase]
-      end
-
-      persisted_rows = Post.order(:id)
-                           .where('LOWER(url) IN (?)', target_keys)
-                           .pluck(:id, :url)
-                           .reject { |post_id, original_url| target_pairs[post_id] == original_url.downcase }
-                           .map { |post_id, original_url|
-        { url: original_url,
-          post_id:,
-          original_url:,
-          conflict_key: original_url.downcase }
-      }
-
-      target_conflicts = target_rows.map { { url: _1.fetch(:sanitised_url),
-                                             post_id: _1.fetch(:post_id),
-                                             original_url: _1.fetch(:original_url),
-                                             conflict_key: _1.fetch(:sanitised_url).downcase } }
-
-      (persisted_rows + target_conflicts)
-          .group_by { _1.fetch(:conflict_key) }
-          .values
-          .filter { _1.size > 1 }
-          .flatten
-          .map { _1.except(:conflict_key) }
-    end
-  end
-
-  private
-
-  def source_pattern_must_be_regexp
-    return if source_pattern.blank?
-
-    Regexp.new(source_pattern)
-  rescue RegexpError
-    errors.add :source_pattern, '変な正規表現だね〜（笑）'
-  end
-end

backend/app/models/post_version.rb

@@ -5,7 +5,6 @@ class PostVersion < ApplicationRecord
   belongs_to :parent, class_name: 'Post', optional: true
 
   validates :url, presence: true
-  validates :video_ms, numericality: { only_integer: true, greater_than: 0 }, allow_nil: true
 
   validate :validate_original_created_range
 

backend/app/models/setting.rb

@@ -1,52 +1,7 @@
 class Setting < ApplicationRecord
-  THEMES = ['system', 'light', 'dark'].freeze
-
-  # These remain in the typed settings schema to preserve existing backend
-  # work. The common `/users/settings` page currently surfaces only `theme`.
-  AUTO_FETCH_MODES = ['auto', 'manual', 'off'].freeze
-  WIKI_EDITOR_MODES = ['split', 'write', 'preview'].freeze
-
-  STRING_ATTRIBUTES = [
-    'theme',
-    'auto_fetch_title',
-    'auto_fetch_thumbnail',
-    'wiki_editor_mode',
-  ].freeze
-  INTEGER_ATTRIBUTES = [].freeze
-  BOOLEAN_ATTRIBUTES = [].freeze
-  EDITABLE_ATTRIBUTES =
-      (STRING_ATTRIBUTES + INTEGER_ATTRIBUTES + BOOLEAN_ATTRIBUTES).freeze
-  TYPE_BY_ATTRIBUTE = {
-    'theme' => :string,
-    'auto_fetch_title' => :string,
-    'auto_fetch_thumbnail' => :string,
-    'wiki_editor_mode' => :string,
-  }.freeze
-
   belongs_to :user
 
   validates :user_id, presence: true
-  validates :user_id, uniqueness: true
-
-  validates :theme, inclusion: { in: THEMES }
-  validates :auto_fetch_title, inclusion: { in: AUTO_FETCH_MODES }
-  validates :auto_fetch_thumbnail, inclusion: { in: AUTO_FETCH_MODES }
-  validates :wiki_editor_mode, inclusion: { in: WIKI_EDITOR_MODES }
-
-  def self.defaults
-    {
-      theme: 'system',
-      auto_fetch_title: 'manual',
-      auto_fetch_thumbnail: 'manual',
-      wiki_editor_mode: 'split',
-    }
-  end
-
-  def self.serializable_attributes
-    EDITABLE_ATTRIBUTES.map(&:to_sym)
-  end
-
-  def serializable_hash(options = nil)
-    super({ only: self.class.serializable_attributes }.merge(options || { }))
-  end
+  validates :key, presence: true, length: { maximum: 255 }
+  validates :value, presence: true
 end

backend/app/models/tag.rb

@@ -8,25 +8,6 @@ class Tag < ApplicationRecord
     ;
   end
 
-  class DeprecatedTagNormalisationError < ArgumentError
-    attr_reader :tag_names
-
-    def initialize tag_names
-      @tag_names = Array(tag_names)
-      super('deprecated tags are not allowed')
-    end
-  end
-
-  class SectionLiteralParseError < ArgumentError
-    attr_reader :tag_name, :literal
-
-    def initialize tag_name, literal
-      @tag_name = tag_name
-      @literal = literal
-      super("invalid section literal for tag #{ tag_name }: #{ literal }")
-    end
-  end
-
   has_many :post_tags, inverse_of: :tag
   has_many :active_post_tags, -> { kept }, class_name: 'PostTag', inverse_of: :tag
   has_many :post_tags_with_discarded, -> { with_discarded }, class_name: 'PostTag'
@@ -59,8 +40,6 @@ class Tag < ApplicationRecord
   belongs_to :tag_name
   delegate :wiki_page, to: :tag_name
 
-  attribute :version_no, :integer, default: 1
-
   delegate :name, to: :tag_name, allow_nil: true
   validates :tag_name, presence: true
 
@@ -77,7 +56,6 @@ class Tag < ApplicationRecord
   validate :nico_tag_name_must_start_with_nico
   validate :tag_name_must_be_canonical
   validate :category_must_be_deerjikist_with_deerjikists
-  validate :nico_tags_cannot_be_deprecated
 
   scope :nico_tags, -> { nico }
 
@@ -97,14 +75,10 @@ class Tag < ApplicationRecord
     (self.tag_name ||= build_tag_name).name = val
   end
 
-  def deprecated? = deprecated_at?
-
   def has_wiki = wiki_page.present?
 
   def material_id = materials.first&.id
 
-  def has_deerjikists = deerjikists.loaded? ? deerjikists.any? : deerjikists.exists?
-
   def self.tagme = find_or_create_by_tag_name!('タグ希望', category: :meta)
   def self.bot = find_or_create_by_tag_name!('bot操作', category: :meta)
   def self.no_deerjikist = find_or_create_by_tag_name!('ニジラー情報不詳', category: :meta)
@@ -114,61 +88,22 @@ class Tag < ApplicationRecord
 
   def self.normalise_tags! tag_names, with_tagme: true,
                                       with_no_deerjikist: true,
-                                      deny_nico: true,
-                                      deny_deprecated: false,
-                                      with_sections: false
+                                      deny_nico: true
     if deny_nico && tag_names.any? { |n| n.downcase.start_with?('nico:') }
       raise NicoTagNormalisationError
     end
 
-    sections = { }
     tags = tag_names.map do |name|
-      raw_name = name
       pf, cat = CATEGORY_PREFIXES.find { |p, _| name.downcase.start_with?(p) } || ['', nil]
-
-      name = name.sub(/\A#{ pf }/i, '')
-
-      sections_by_tag = []
-      while (match = name.match(/\A(\S*?)\[([^\[\]\s]*)-([^\[\]\s]*)\](\S*)\z/))
-        name = "#{ match[1] }#{ match[4] }"
-        next if match[2].empty? && match[3].empty?
-
-        sections_by_tag << normalise_section_range!(
-            begin_raw: match[2],
-            end_raw: match[3],
-            tag_name: name)
-      end
-
-      if name.include?('[') || name.include?(']')
-        raise SectionLiteralParseError.new(raw_name, raw_name)
-      end
-
-      name = TagName.canonicalise(name).first
-
+      name = TagName.canonicalise(name.sub(/\A#{ pf }/i, '')).first
       find_or_create_by_tag_name!(name, category: (cat || :general)).tap do |tag|
-        if deny_deprecated && tag.deprecated?
-          raise DeprecatedTagNormalisationError, [tag.name]
-        end
-
         tag.update!(category: cat) if cat && tag.category != cat
-        next if sections_by_tag.empty?
-
-        sections[tag.id] ||= []
-        sections[tag.id].concat(sections_by_tag)
-        sections[tag.id] = merge_section_ranges(sections[tag.id])
-        sections.delete(tag.id) if sections[tag.id] == [[0, nil]]
       end
     end
 
     tags << Tag.tagme if with_tagme && tags.size < 10 && tags.none?(Tag.tagme)
     tags << Tag.no_deerjikist if with_no_deerjikist && tags.all? { |t| !(t.deerjikist?) }
-    tags.uniq!(&:id)
-
-    if with_sections
-      { tags:, sections: }
-    else
-      tags
-    end
+    tags.uniq(&:id)
   end
 
   def self.expand_parent_tags tags
@@ -194,45 +129,6 @@ class Tag < ApplicationRecord
     (result + tags).uniq { |t| t.id }
   end
 
-  def self.normalise_section_range! begin_raw:, end_raw:, tag_name:
-    begin_ms = begin_raw.empty? ? 0 : time_to_ms!(begin_raw, tag_name:)
-    end_ms = end_raw.empty? ? nil : time_to_ms!(end_raw, tag_name:)
-
-    if end_ms
-      begin_ms, end_ms = end_ms, begin_ms if begin_ms > end_ms
-      end_ms = begin_ms + 1 if begin_ms == end_ms
-    end
-
-    [begin_ms, end_ms]
-  end
-
-  def self.merge_section_ranges ranges
-    sorted_ranges = ranges.sort_by { |begin_ms, end_ms| [begin_ms, end_ms || Float::INFINITY] }
-    merged = []
-
-    sorted_ranges.each do |begin_ms, end_ms|
-      if merged.empty?
-        merged << [begin_ms, end_ms]
-        next
-      end
-
-      last_begin_ms, last_end_ms = merged[-1]
-      if last_end_ms.nil? || begin_ms <= last_end_ms
-        merged[-1] = [last_begin_ms, merge_section_end(last_end_ms, end_ms)]
-      else
-        merged << [begin_ms, end_ms]
-      end
-    end
-
-    merged
-  end
-
-  def self.merge_section_end left_end_ms, right_end_ms
-    return nil if left_end_ms.nil? || right_end_ms.nil?
-
-    [left_end_ms, right_end_ms].max
-  end
-
   def self.find_or_create_by_tag_name! name, category:
     tn = TagName.find_undiscard_or_create_by!(name: name.to_s.strip)
     tn = tn.canonical if tn.canonical_id?
@@ -328,36 +224,4 @@ class Tag < ApplicationRecord
       errors.add :category, 'ニジラーと紐づいてゐるタグはニジラー・カテゴリである必要があります．'
     end
   end
-
-  def self.time_to_ms! str, tag_name:
-    match =
-        case str
-        when /\A(?<seconds>\d+)(?:\.(?<ms>\d{1,3}))?\z/
-          { hours: nil, minutes: nil, seconds: Regexp.last_match[:seconds],
-            ms: Regexp.last_match[:ms] }
-        when /\A(?<minutes>\d+):(?<seconds>[0-5]?\d)(?:\.(?<ms>\d{1,3}))?\z/
-          { hours: nil, minutes: Regexp.last_match[:minutes],
-            seconds: Regexp.last_match[:seconds],
-            ms: Regexp.last_match[:ms] }
-        when /\A(?<hours>\d+):(?<minutes>[0-5]?\d):(?<seconds>[0-5]?\d)(?:\.(?<ms>\d{1,3}))?\z/
-          { hours: Regexp.last_match[:hours],
-            minutes: Regexp.last_match[:minutes],
-            seconds: Regexp.last_match[:seconds],
-            ms: Regexp.last_match[:ms] }
-        end
-
-    raise SectionLiteralParseError.new(tag_name, str) unless match
-
-    total_s = match[:seconds].to_i
-    total_s += match[:minutes].to_i * 60 if match[:minutes]
-    total_s += match[:hours].to_i * 3_600 if match[:hours]
-
-    total_s * 1_000 + match[:ms].to_s.ljust(3, '0')[0, 3].to_i
-  end
-
-  def nico_tags_cannot_be_deprecated
-    if nico? && deprecated_at.present?
-      errors.add :deprecated_at, 'ニコタグは廃止できません．'
-    end
-  end
 end

backend/app/models/tag_implication.rb

@@ -6,7 +6,6 @@ class TagImplication < ApplicationRecord
   validates :parent_tag_id, presence: true
 
   validate :parent_tag_mustnt_be_itself
-  validate :parent_tag_mustnt_create_cycle
 
   private
 
@@ -15,27 +14,4 @@ class TagImplication < ApplicationRecord
       errors.add :parent_tag_id, '親タグは子タグと同一であってはなりません．'
     end
   end
-
-  def parent_tag_mustnt_create_cycle
-    return if tag_id.blank? || parent_tag_id.blank?
-    return if errors[:parent_tag_id].present?
-
-    seen = { }
-    stack = [parent_tag_id]
-
-    until stack.empty?
-      current_id = stack.pop
-      next if seen[current_id]
-
-      seen[current_id] = true
-
-      if current_id == tag_id
-        errors.add :parent_tag_id, '親タグに子孫タグを指定すると循環します．'
-        errors.add :base, 'タグの親子関係が循環します．'
-        return
-      end
-
-      stack.concat(TagImplication.where(tag_id: current_id).pluck(:parent_tag_id))
-    end
-  end
 end

backend/app/models/theatre.rb

@@ -7,10 +7,6 @@ class Theatre < ApplicationRecord
            class_name: 'TheatreWatchingUser', inverse_of: :theatre
   has_many :watching_users, through: :active_theatre_watching_users, source: :user
 
-  has_many :programmes, class_name: 'TheatreProgramme'
-  has_many :skip_votes, class_name: 'TheatreSkipVote', dependent: :delete_all
-  has_many :skip_events, class_name: 'TheatreSkipEvent', dependent: :delete_all
-
   belongs_to :host_user, class_name: 'User', optional: true
   belongs_to :current_post, class_name: 'Post', optional: true
   belongs_to :created_by_user, class_name: 'User'

backend/app/models/theatre_programme.rb

@@ -1,6 +0,0 @@
-class TheatreProgramme < ApplicationRecord
-  self.primary_key = :theatre_id, :position
-
-  belongs_to :theatre
-  belongs_to :post
-end

backend/app/models/theatre_skip_event.rb

@@ -1,10 +0,0 @@
-class TheatreSkipEvent < ApplicationRecord
-  belongs_to :theatre
-  belongs_to :post
-  belongs_to :skipped_by_user, class_name: 'User'
-
-  has_many :voters, class_name: 'TheatreSkipEventVoter', dependent: :delete_all
-  has_many :event_tags, class_name: 'TheatreSkipEventTag', dependent: :delete_all
-  has_many :users, through: :voters
-  has_many :tags, through: :event_tags
-end

backend/app/models/theatre_skip_event_tag.rb

@@ -1,6 +0,0 @@
-class TheatreSkipEventTag < ApplicationRecord
-  self.primary_key = :theatre_skip_event_id, :tag_id
-
-  belongs_to :theatre_skip_event
-  belongs_to :tag
-end

backend/app/models/theatre_skip_event_voter.rb

@@ -1,6 +0,0 @@
-class TheatreSkipEventVoter < ApplicationRecord
-  self.primary_key = :theatre_skip_event_id, :user_id
-
-  belongs_to :theatre_skip_event
-  belongs_to :user
-end

backend/app/models/theatre_skip_vote.rb

@@ -1,7 +0,0 @@
-class TheatreSkipVote < ApplicationRecord
-  self.primary_key = :theatre_id, :post_id, :user_id
-
-  belongs_to :theatre
-  belongs_to :post
-  belongs_to :user
-end

backend/app/models/user.rb

@@ -4,11 +4,11 @@ class User < ApplicationRecord
   validates :name, length: { maximum: 255 }
   validates :inheritance_code, presence: true, length: { maximum: 64 }
   validates :role, presence: true, inclusion: { in: roles.keys }
+  validates :banned, inclusion: { in: [true, false] }
 
   has_many :created_posts,
            class_name: 'Post', foreign_key: :uploaded_user_id, dependent: :nullify
-  has_one :setting, dependent: :destroy
-  has_many :theme_slots, class_name: 'UserThemeSlot', dependent: :destroy
+  has_many :settings
   has_many :user_ips, dependent: :destroy
   has_many :ip_addresses, through: :user_ips
   has_many :user_post_views, dependent: :destroy
@@ -19,10 +19,5 @@ class User < ApplicationRecord
            class_name: 'WikiPage', foreign_key: :updated_user_id, dependent: :nullify
 
   def viewed?(post) = user_post_views.exists?(post_id: post.id)
-
   def gte_member? = member? || admin?
-
-  def banned? = banned_at.present?
-  def ban! = banned? || update!(banned_at: Time.current)
-  def unban! = update!(banned_at: nil)
 end

backend/app/models/user_theme_slot.rb

@@ -1,27 +0,0 @@
-class UserThemeSlot < ApplicationRecord
-  BASE_THEMES = ['light', 'dark'].freeze
-  SLOT_NOS = [1, 2, 3].freeze
-
-  belongs_to :user
-
-  validates :user_id, presence: true
-  validates :base_theme, presence: true, inclusion: { in: BASE_THEMES }
-  validates :slot_no, presence: true, inclusion: { in: SLOT_NOS }
-  validates :tokens, presence: true
-  validates :user_id, uniqueness: { scope: [:base_theme, :slot_no] }
-
-  validate :tokens_must_be_object
-
-  def serializable_hash(options = nil)
-    hash = { only: [:base_theme, :slot_no, :tokens, :created_at, :updated_at] }
-    super(hash.merge(options || {}))
-  end
-
-  private
-
-  def tokens_must_be_object
-    return if tokens.is_a?(Hash)
-
-    errors.add(:tokens, 'は JSON object で指定してください．')
-  end
-end

backend/app/models/version_record.rb

@@ -1,23 +1,15 @@
 module VersionRecord
   extend ActiveSupport::Concern
 
-  DEFAULT_EVENT_TYPE_MAP = { create: 'create',
-                             update: 'update',
-                             discard: 'discard',
-                             restore: 'restore' }.freeze
-
   def readonly? = persisted?
 
   included do
-    event_type_map = if const_defined?(:EVENT_TYPE_MAP, false)
-                       const_get(:EVENT_TYPE_MAP)
-                     else
-                       DEFAULT_EVENT_TYPE_MAP
-                     end
-
     belongs_to :created_by_user, class_name: 'User', optional: true
 
-    enum :event_type, event_type_map, prefix: true, validate: true
+    enum :event_type, { create: 'create',
+                        update: 'update',
+                        discard: 'discard',
+                        restore: 'restore' }, prefix: true, validate: true
 
     validates :version_no, presence: true, numericality: { only_integer: true, greater_than: 0 }
     validates :event_type, presence: true

backend/app/models/wiki_page.rb

@@ -15,14 +15,11 @@ class WikiPage < ApplicationRecord
 
   has_many :wiki_versions
 
-  attribute :version_no, :integer, default: 1
-
   belongs_to :tag_name
   validates :tag_name, presence: true
   validates :body, presence: true
 
   def title = tag_name.name
-  def deprecated_at = tag_name.tag&.deprecated_at
 
   def title= val
     (self.tag_name ||= build_tag_name).name = val

backend/app/representations/material_repr.rb

@@ -2,9 +2,7 @@
 
 
 module MaterialRepr
-  BASE = { only: [:id, :url, :version_no, :source_kind, :source_uri,
-                  :source_path, :source_file_id, :normalized_source_key,
-                  :created_at, :updated_at],
+  BASE = { only: [:id, :url, :created_at, :updated_at],
            methods: [:content_type],
            include: { tag: TagRepr::BASE,
                       created_by_user: UserRepr::BASE,
@@ -17,93 +15,10 @@ module MaterialRepr
         file: if material.file.attached?
                 Rails.application.routes.url_helpers.rails_storage_proxy_url(
                     material.file, host:)
-              end,
-        thumbnail: thumbnail_url(material, host:),
-        thumbnail_fallback_text: thumbnail_fallback_text(material),
-        thumbnail_fallback_kind: thumbnail_fallback_kind(material),
-        media_kind: media_kind(material),
-        file_byte_size: material.file_byte_size,
-        export_paths: export_paths(material),
-        export_items: export_items(material))
+              end)
   end
 
   def many materials, host:
     materials.map { |m| base(m, host:) }
   end
-
-  def list material, host:
-    { id: material.id,
-      version_no: material.version_no,
-      url: material.url,
-      source_kind: material.source_kind,
-      source_uri: material.source_uri,
-      source_path: material.source_path,
-      source_file_id: material.source_file_id,
-      normalized_source_key: material.normalized_source_key,
-      tag: compact_tag(material.tag),
-      thumbnail: thumbnail_url(material, host:),
-      thumbnail_fallback_text: thumbnail_fallback_text(material),
-      thumbnail_fallback_kind: thumbnail_fallback_kind(material),
-      media_kind: media_kind(material),
-      content_type: material.content_type,
-      file_byte_size: material.file_byte_size,
-      created_at: material.created_at,
-      updated_at: material.updated_at,
-      export_paths: export_paths(material),
-      export_items: export_items(material) }
-  end
-
-  def list_many materials, host:
-    materials.map { |m| list(m, host:) }
-  end
-
-  def export_paths material
-    material.material_export_items.each_with_object({ }) do |item, hash|
-      hash[item.profile] = item.enabled ? item.export_path : ''
-    end
-  end
-
-  def export_items material
-    material.material_export_items.map do |item|
-      { id: item.id,
-        profile: item.profile,
-        export_path: item.export_path,
-        enabled: item.enabled }
-    end
-  end
-
-  def thumbnail_url material, host:
-    return nil unless material.thumbnail.attached?
-
-    Rails.application.routes.url_helpers.rails_storage_proxy_url(
-        material.thumbnail, host:)
-  end
-
-  def thumbnail_fallback_text material
-    material.tag&.name || material.created_at&.strftime('%Y-%m-%d')
-  end
-
-  def thumbnail_fallback_kind material
-    material.tag.present? ? 'tag_name' : 'created_at'
-  end
-
-  def media_kind material
-    return 'url_only' unless material.file.attached?
-
-    content_type = material.file.blob.content_type.to_s
-    return 'image' if content_type.start_with?('image/')
-    return 'video' if content_type.start_with?('video/')
-    return 'audio' if content_type.start_with?('audio/')
-
-    'file_other'
-  end
-
-  def compact_tag tag
-    return nil unless tag
-
-    { id: tag.id,
-      name: tag.name,
-      category: tag.category,
-      deprecated_at: tag.deprecated_at }
-  end
 end

backend/app/representations/post_compact_repr.rb

@@ -1,19 +0,0 @@
-# frozen_string_literal: true
-
-
-module PostCompactRepr
-  module_function
-
-  def base post, host: nil
-    return nil if post.nil?
-
-    PostRepr
-        .common(post, host:)
-        .slice(
-            'id',
-            'title',
-            'url',
-            'thumbnail',
-            'thumbnail_base')
-  end
-end

backend/app/representations/post_repr.rb

@@ -2,115 +2,20 @@
 
 
 module PostRepr
-  BASE_FIELDS = [
-      :id,
-      :version_no,
-      :url,
-      :title,
-      :thumbnail_base,
-      :video_ms,
-      :original_created_from,
-      :original_created_before,
-      :created_at,
-      :updated_at
-  ].freeze
+  BASE = { include: { tags: TagRepr::BASE, uploaded_user: UserRepr::BASE },
+           methods: [:parent_posts, :child_posts, :sibling_posts] }.freeze
 
   module_function
 
-  def base post, current_user = nil, host: nil
-    json =
-        if host.present?
-          common(post, host:)
-        else
-          common(post)
-        end
-    json['tags'] = tag_json(post)
-    json['uploaded_user'] = post.uploaded_user && UserRepr.base(post.uploaded_user)
-    json['viewed'] = current_user ? current_user.viewed?(post) : false
-    json
+  def base post, current_user = nil
+    json = post.as_json(BASE)
+    return json.merge(viewed: false) unless current_user
+
+    viewed = current_user.viewed?(post)
+    json.merge(viewed:)
   end
 
-  def detail post, current_user = nil, parent_posts: [], child_posts: [],
-             sibling_posts: { }, related: [], host: nil
-    if host.present?
-      base(post, current_user, host:).merge(
-          'parent_posts' => cards(parent_posts, host:),
-          'child_posts' => cards(child_posts, host:),
-          'sibling_posts' => sibling_posts.transform_keys(&:to_s).transform_values { |posts|
-            cards(posts, host:)
-          },
-          'related' => cards(related, host:))
-    else
-      base(post, current_user).merge(
-          'parent_posts' => cards(parent_posts),
-          'child_posts' => cards(child_posts),
-          'sibling_posts' => sibling_posts.transform_keys(&:to_s).transform_values { |posts|
-            cards(posts)
-          },
-          'related' => cards(related))
-    end
-  end
-
-  def card post, host: nil
-    if host.present?
-      common(post, host:).merge('parent_posts' => [], 'child_posts' => [])
-    else
-      common(post).merge('parent_posts' => [], 'child_posts' => [])
-    end
-  end
-
-  def cards posts, host: nil
-    if host.present?
-      posts.map { |post| card(post, host:) }
-    else
-      posts.map { |post| card(post) }
-    end
-  end
-
-  def many posts, current_user = nil, host: nil
-    if host.present?
-      posts.map { |p| base(p, current_user, host:) }
-    else
-      posts.map { |p| base(p, current_user) }
-    end
-  end
-
-  def common post, host: nil
-    BASE_FIELDS.to_h { |field| [field.to_s, post.public_send(field)] }
-               .merge(
-                   'thumbnail' =>
-                       if host.present?
-                         thumbnail_url(post, host:)
-                       else
-                         thumbnail_url(post)
-                       end)
-  end
-
-  def tag_json post
-    post
-        .active_post_tags
-        .reject { _1.tag.deprecated? }
-        .sort_by { _1.tag.name }
-        .map { |post_tag|
-      TagRepr.inline(post_tag.tag).merge(
-          'children' => [],
-          'sections' => post_tag.sections.as_json(only: [:begin_ms, :end_ms]))
-    }
-  end
-
-  def thumbnail_url post, host: nil
-    return nil unless post.thumbnail.attached?
-
-    options = { only_path: false }
-    options[:host] = host if host.present?
-
-    Rails.application.routes.url_helpers.rails_storage_proxy_url(post.thumbnail, **options)
-  rescue ActionController::UrlGenerationError, ArgumentError, URI::InvalidURIError => e
-    Rails.logger.warn(
-        "PostRepr.thumbnail_url failed post_id=#{post.id} " \
-        "attachment_id=#{post.thumbnail.attachment&.id} " \
-        "blob_id=#{post.thumbnail.blob&.id} " \
-        "error_class=#{e.class} message=#{e.message}")
-    nil
+  def many posts, current_user = nil
+    posts.map { |p| base(p, current_user) }
   end
 end

backend/app/representations/tag_repr.rb

@@ -2,8 +2,8 @@
 
 
 module TagRepr
-  BASE = { only: [:id, :category, :post_count, :created_at, :updated_at, :deprecated_at],
-           methods: [:name, :has_wiki, :material_id, :has_deerjikists] }.freeze
+  BASE = { only: [:id, :category, :post_count, :created_at, :updated_at],
+           methods: [:name, :has_wiki, :material_id] }.freeze
 
   module_function
 
@@ -12,9 +12,5 @@ module TagRepr
                             parents: tag.parents.map { _1.as_json(BASE) })
   end
 
-  def inline tag
-    tag.as_json(BASE).merge(aliases: [], parents: [])
-  end
-
   def many(tags) = tags.map { |t| base(t) }
 end

backend/app/representations/wiki_page_repr.rb

@@ -2,7 +2,7 @@
 
 
 module WikiPageRepr
-  BASE = { methods: [:title, :deprecated_at] }.freeze
+  BASE = { methods: [:title] }.freeze
 
   module_function
 

backend/app/services/gekanator/ai_run_budget.rb

@@ -1,22 +0,0 @@
-module Gekanator
-  class AiRunBudget
-    MONTHLY_LIMIT_JPY = BigDecimal('450').freeze
-    MAX_RUN_ESTIMATED_COST_JPY = BigDecimal('5').freeze
-
-    def self.remaining_monthly_budget_jpy
-      MONTHLY_LIMIT_JPY - monthly_cost_jpy
-    end
-
-    def self.monthly_cost_jpy
-      GekanatorAiRun.this_month.sum(:estimated_cost_jpy)
-    end
-
-    def self.exceeded?
-      monthly_cost_jpy >= MONTHLY_LIMIT_JPY
-    end
-
-    def self.exceeded_after_next_run?
-      monthly_cost_jpy + MAX_RUN_ESTIMATED_COST_JPY >= MONTHLY_LIMIT_JPY
-    end
-  end
-end

backend/app/services/gekanator/question_suggestion_ai_converter.rb

@@ -1,168 +0,0 @@
-module Gekanator
-  class QuestionSuggestionAiConverter
-    # Temporary heuristic converter for #361.
-    # This creates pending ai_generated questions without external LLM calls;
-    # accepted questions are still distributed only after admin approval.
-    TITLE_LENGTH_RE = /\Aタイトルは\s*(\d+)\s*文字以上[？?]\z/
-    ORIGINAL_YEAR_RE = /\Aオリジナルの投稿年は\s*(\d{4})\s*年[？?]\z/
-    ORIGINAL_MONTH_RE = /\Aオリジナルの投稿月は\s*(\d{1,2})\s*月[？?]\z/
-    ORIGINAL_MONTH_DAY_RE = /\Aオリジナルの投稿日は\s*(\d{1,2})\s*月\s*(\d{1,2})\s*日[？?]\z/
-    TITLE_CONTAINS_RE = /\A題名に「(.+?)」が含まれる[？?]\z/
-    SOURCE_RE = /\A(.+?)\s+の投稿を思[ひい]浮かべて[ゐい]る[？?]\z/
-
-    def self.call(...) = new(...).call
-
-    def initialize suggestion:, user:
-      @suggestion = suggestion
-      @user = user
-    end
-
-    def call
-      suggestion.with_lock do
-        existing = existing_generated_question
-        return existing if existing
-
-        run = suggestion.gekanator_ai_runs.create!(
-            model: 'heuristic_converter_v1',
-            status: 'running',
-            input_tokens: 0,
-            output_tokens: 0,
-            estimated_cost_jpy: 0)
-
-        question_attributes = build_question
-        question =
-            question_attributes &&
-            GekanatorQuestion.create!(
-                **question_attributes,
-                source: 'ai_generated',
-                status: 'pending',
-                gekanator_question_suggestion: suggestion,
-                created_by: user)
-
-        run.update!(status: question ? 'succeeded' : 'failed')
-        question
-      end
-    rescue => error
-      run&.update!(status: 'failed') if run&.persisted? && run.status != 'failed'
-      raise error
-    end
-
-    private
-
-    attr_reader :suggestion, :user
-
-    def existing_generated_question
-      suggestion
-          .gekanator_questions
-          .where(source: 'ai_generated')
-          .order(id: :desc)
-          .first
-    end
-
-    def build_question
-      text = normalized_text
-      return nil if text.blank?
-
-      structured_question_for(text) || post_similarity_question_for(text)
-    end
-
-    def normalized_text
-      suggestion.question_text.to_s.gsub(/[[:space:]]+/, ' ').strip
-    end
-
-    def structured_question_for text
-      case text
-      when TITLE_LENGTH_RE
-        length = Regexp.last_match(1).to_i
-        return nil if length <= 0
-
-        {
-          text:,
-          kind: 'title',
-          condition: {
-            type: 'title-length-at-least',
-            length:
-          },
-          priority_weight: 0.95
-        }
-      when /\A題名に英数字が混じって[ゐい]る[？?]\z/
-        {
-          text: '題名に英数字が混じってゐる?',
-          kind: 'title',
-          condition: { type: 'title-has-ascii' },
-          priority_weight: 0.95
-        }
-      when ORIGINAL_YEAR_RE
-        year = Regexp.last_match(1).to_i
-        {
-          text:,
-          kind: 'original_date',
-          condition: { type: 'original-year', year: },
-          priority_weight: 0.95
-        }
-      when ORIGINAL_MONTH_RE
-        month = Regexp.last_match(1).to_i
-        return nil unless month.between?(1, 12)
-
-        {
-          text:,
-          kind: 'original_date',
-          condition: { type: 'original-month', month: },
-          priority_weight: 0.95
-        }
-      when ORIGINAL_MONTH_DAY_RE
-        month = Regexp.last_match(1).to_i
-        day = Regexp.last_match(2).to_i
-        return nil unless month.between?(1, 12) && day.between?(1, 31)
-
-        {
-          text:,
-          kind: 'original_date',
-          condition: {
-            type: 'original-month-day',
-            monthDay: "#{ month }-#{ day }"
-          },
-          priority_weight: 0.95
-        }
-      when TITLE_CONTAINS_RE
-        title_text = Regexp.last_match(1).to_s.strip
-        return nil if title_text.blank?
-
-        {
-          text: "題名に「#{ title_text }」が含まれる?",
-          kind: 'title',
-          condition: { type: 'title-contains', text: title_text },
-          priority_weight: 0.95
-        }
-      when SOURCE_RE
-        host = Regexp.last_match(1).to_s.strip
-        return nil if host.blank?
-
-        {
-          text:,
-          kind: 'source',
-          condition: { type: 'source', host: },
-          priority_weight: 0.95
-        }
-      else
-        nil
-      end
-    end
-
-    def post_similarity_question_for text
-      return nil if suggestion.answer == 'unknown'
-
-      {
-        text:,
-        kind: 'post_similarity',
-        condition: {
-          type: 'post-similarity',
-          postId: suggestion.gekanator_game.correct_post_id,
-          answer: suggestion.answer,
-          threshold: 0.65
-        },
-        priority_weight: 1.0
-      }
-    end
-  end
-end

backend/app/services/gekanator/question_suggestion_promoter.rb

@@ -1,52 +0,0 @@
-module Gekanator
-  class QuestionSuggestionPromoter
-    def self.call(...) = new(...).call
-
-    def initialize suggestion:, user:
-      @suggestion = suggestion
-      @user = user
-    end
-
-    def call
-      suggestion.with_lock do
-        return promoted_question if suggestion.processed?
-        return suggestion if suggestion.answer == 'unknown'
-
-        question = GekanatorQuestion.create!(
-            text: suggestion.question_text,
-            kind: 'post_similarity',
-            source: 'user_suggested',
-            status: 'accepted',
-            priority_weight: 1.2,
-            condition: {
-              type: 'post-similarity',
-              postId: suggestion.gekanator_game.correct_post_id,
-              answer: suggestion.answer,
-              threshold: 0.65
-            },
-            gekanator_question_suggestion: suggestion,
-            created_by: user)
-        example =
-            GekanatorQuestionExample.new(
-                gekanator_question: question,
-                post: suggestion.gekanator_game.correct_post,
-                user: user)
-        example.record_answer!(
-            answer: suggestion.answer,
-            source: 'initial_suggestion',
-            gekanator_game: suggestion.gekanator_game)
-        example.save!
-        suggestion.update!(processed: true)
-        question
-      end
-    end
-
-    private
-
-    attr_reader :suggestion, :user
-
-    def promoted_question
-      suggestion.gekanator_questions.order(id: :desc).first
-    end
-  end
-end

backend/app/services/google_drive/api_client.rb

@@ -1,233 +0,0 @@
-require 'json'
-require 'jwt'
-require 'net/http'
-require 'openssl'
-require 'tempfile'
-require 'uri'
-
-
-module GoogleDrive
-  class ApiClient
-    DRIVE_ENDPOINT = 'https://www.googleapis.com/drive/v3'
-    TOKEN_ENDPOINT = 'https://oauth2.googleapis.com/token'
-    FOLDER_MIME_TYPE = 'application/vnd.google-apps.folder'
-    NATIVE_FILE_MIME_TYPE_PREFIX = 'application/vnd.google-apps.'
-    DRIVE_SCOPE = 'https://www.googleapis.com/auth/drive.readonly'
-
-    def initialize service_account_email: ENV['GOOGLE_DRIVE_SERVICE_ACCOUNT_EMAIL'],
-                   private_key: ENV['GOOGLE_DRIVE_PRIVATE_KEY'],
-                   private_key_path: ENV['GOOGLE_DRIVE_PRIVATE_KEY_PATH'],
-                   subject: ENV['GOOGLE_DRIVE_SUBJECT']
-      @service_account_email = service_account_email.to_s
-      @private_key = load_private_key(private_key, private_key_path)
-      @subject = subject.to_s.presence
-      @access_token = nil
-    end
-
-    def list_material_files_under_folder folder_id
-      files = []
-      each_material_file_under_folder(folder_id) { |entry| files << entry }
-      files
-    end
-
-    def each_material_file_under_folder folder_id
-      return enum_for(__method__, folder_id) unless block_given?
-
-      walk_folder(folder_id, nil) do |entry, relative_path|
-        next if entry['mimeType'] == FOLDER_MIME_TYPE
-        next if native_file?(entry['mimeType'])
-
-        yield build_file_entry(entry, relative_path)
-      end
-    end
-
-    def fetch_material_file file_id
-      metadata = get_file(file_id)
-      return nil if native_file?(metadata['mimeType'])
-
-      build_file_entry(metadata, metadata['name'])
-    end
-
-    def download_to_tempfile file_id, filename:
-      tempfile = Tempfile.new(['material-sync', File.extname(filename.to_s)])
-      tempfile.binmode
-      request_binary("/files/#{ file_id }",
-                     { alt: 'media', supportsAllDrives: true }) do |chunk|
-        tempfile.write(chunk.b)
-      end
-      tempfile.rewind
-      tempfile
-    rescue StandardError
-      tempfile&.close!
-      raise
-    end
-
-    def extract_file_id value
-      raw = value.to_s.strip
-      return nil if raw.blank?
-      return raw unless raw.include?('/')
-
-      uri = URI.parse(raw)
-      return uri.query.to_s[%r{(?:^|&)id=([^&]+)}, 1] if uri.query.present?
-      return uri.path[%r{/folders/([^/]+)}, 1] if uri.path.include?('/folders/')
-
-      uri.path[%r{/d/([^/]+)}, 1]
-    rescue URI::InvalidURIError
-      nil
-    end
-
-    private
-
-    def walk_folder folder_id, prefix, &block
-      list_children(folder_id).each do |entry|
-        relative_path = MaterialSyncExportPath.build(prefix:,
-                                                     relative_path: entry['name'])
-        if entry['mimeType'] == FOLDER_MIME_TYPE
-          walk_folder(entry['id'], relative_path, &block)
-          next
-        end
-
-        block.call(entry, relative_path)
-      end
-    end
-
-    def build_file_entry entry, relative_path
-      { id: entry['id'],
-        name: entry['name'],
-        mime_type: entry['mimeType'],
-        relative_path: MaterialSyncExportPath.normalize_path(relative_path),
-        sha256_checksum: entry['sha256Checksum'],
-        web_view_link: entry['webViewLink'],
-        web_content_link: entry['webContentLink'] }
-    end
-
-    def list_children folder_id
-      files = []
-      page_token = nil
-
-      loop do
-        response =
-            request_json('/files', {
-                q: "'#{ folder_id }' in parents and trashed = false",
-                fields: 'nextPageToken,files(id,name,mimeType,sha256Checksum,' \
-                        'webViewLink,webContentLink)',
-                orderBy: 'folder,name',
-                pageSize: 1000,
-                supportsAllDrives: true,
-                includeItemsFromAllDrives: true,
-                pageToken: page_token }.compact)
-        files.concat(response.fetch('files'))
-        page_token = response['nextPageToken']
-        break if page_token.blank?
-      end
-
-      files
-    end
-
-    def get_file file_id
-      request_json("/files/#{ file_id }",
-                   fields: 'id,name,mimeType,sha256Checksum,webViewLink,webContentLink',
-                   supportsAllDrives: true)
-    end
-
-    def request_json path, params = {}
-      response = request(:get, path, params:)
-      unless response.is_a?(Net::HTTPSuccess)
-        raise "Google Drive API error: #{ response.code } #{ response.body }"
-      end
-
-      JSON.parse(response.body)
-    end
-
-    def request_binary path, params = {}
-      request(:get, path, params:) do |response|
-        unless response.is_a?(Net::HTTPSuccess)
-          raise "Google Drive download error: #{ response.code } #{ response.body }"
-        end
-
-        response.read_body do |chunk|
-          yield chunk.b
-        end
-      end
-    end
-
-    def request method, path, params: nil
-      uri = URI(DRIVE_ENDPOINT + path)
-      uri.query = URI.encode_www_form(params) if params.present?
-
-      klass =
-          case method
-          when :get
-            Net::HTTP::Get
-          else
-            raise ArgumentError, "Unsupported Google Drive request method: #{ method }"
-          end
-      request = klass.new(uri)
-      request['Authorization'] = "Bearer #{ access_token }"
-
-      Net::HTTP.start(uri.host,
-                      uri.port,
-                      use_ssl: true,
-                      open_timeout: 10,
-                      read_timeout: 60) do |http|
-        if block_given?
-          http.request(request) do |response|
-            return yield response
-          end
-        else
-          http.request(request)
-        end
-      end
-    end
-
-    def access_token
-      @access_token ||= fetch_access_token
-    end
-
-    def fetch_access_token
-      raise 'GOOGLE_DRIVE_SERVICE_ACCOUNT_EMAIL is required' if @service_account_email.blank?
-      raise 'Google Drive private key is required' if @private_key.blank?
-
-      payload = { iss: @service_account_email,
-                  scope: DRIVE_SCOPE,
-                  aud: TOKEN_ENDPOINT,
-                  exp: 1.hour.from_now.to_i,
-                  iat: Time.current.to_i }
-      payload[:sub] = @subject if @subject.present?
-
-      assertion = JWT.encode(payload, @private_key, 'RS256')
-      uri = URI(TOKEN_ENDPOINT)
-      request = Net::HTTP::Post.new(uri)
-      request.set_form_data(
-          grant_type: 'urn:ietf:params:oauth:grant-type:jwt-bearer',
-          assertion:)
-
-      response =
-          Net::HTTP.start(uri.host,
-                          uri.port,
-                          use_ssl: true,
-                          open_timeout: 10,
-                          read_timeout: 30) do |http|
-            http.request(request)
-          end
-      unless response.is_a?(Net::HTTPSuccess)
-        raise "Google OAuth error: #{ response.code } #{ response.body }"
-      end
-
-      JSON.parse(response.body).fetch('access_token')
-    end
-
-    def load_private_key private_key, private_key_path
-      raw = private_key.to_s
-      raw = raw.gsub('\n', "\n") if raw.present?
-      raw = File.read(private_key_path) if raw.blank? && private_key_path.present?
-      return nil if raw.blank?
-
-      OpenSSL::PKey::RSA.new(raw)
-    end
-
-    def native_file? mime_type
-      mime_type.to_s.start_with?(NATIVE_FILE_MIME_TYPE_PREFIX)
-    end
-  end
-end

backend/app/services/material_file_sha256.rb

@@ -1,57 +0,0 @@
-require 'digest'
-require 'json'
-
-class MaterialFileSha256
-  def self.blob_metadata blob
-    metadata = blob.metadata
-    return metadata if metadata.is_a?(Hash)
-    return { } if metadata.blank?
-
-    JSON.parse(metadata)
-  rescue JSON::ParserError
-    { }
-  end
-
-  def self.metadata_sha256 blob
-    blob_metadata(blob)['sha256'].presence
-  end
-
-  def self.assign_metadata_sha256! blob, sha256
-    return if sha256.blank?
-
-    metadata = blob_metadata(blob)
-    metadata['sha256'] = sha256
-    blob.metadata = metadata
-    blob.save! if blob.changed?
-  end
-
-  def self.from_blob blob, allow_download: false
-    sha256 = metadata_sha256(blob)
-    return sha256 if sha256.present?
-    return nil unless allow_download
-
-    begin
-      blob.open do |file|
-        sha256 = Digest::SHA256.file(file.path).hexdigest
-        assign_metadata_sha256!(blob, sha256)
-        sha256
-      end
-    rescue ActiveStorage::FileNotFoundError, ArgumentError => error
-      Rails.logger.warn(
-          "MaterialFileSha256.from_blob failed for blob_id=#{blob.id}: " \
-          "#{error.class}: #{error.message}",
-      )
-      nil
-    end
-  end
-
-  def self.from_upload upload
-    tempfile = upload&.tempfile
-    return nil unless tempfile
-
-    tempfile.rewind
-    Digest::SHA256.file(tempfile.path).hexdigest.tap do
-      tempfile.rewind
-    end
-  end
-end

backend/app/services/material_import_block_matcher.rb

@@ -1,7 +0,0 @@
-class MaterialImportBlockMatcher
-  def self.match_for_sha256 sha256
-    return nil if sha256.blank?
-
-    MaterialImportBlock.find_by(match_kind: 'sha256', sha256:)
-  end
-end

backend/app/services/material_sync_export_path.rb

@@ -1,56 +0,0 @@
-class MaterialSyncExportPath
-  class << self
-    def build prefix: nil, relative_path: nil, filename: nil, source_file_id: nil
-      path = normalize_path(relative_path)
-      path = fallback_filename(filename, source_file_id) if path.blank?
-
-      normalized_prefix = normalize_path(prefix)
-      return path if normalized_prefix.blank?
-      return normalized_prefix if path.blank?
-
-      [normalized_prefix, path].join('/')
-    end
-
-    def normalize_path path
-      raw = path.to_s.delete("\0").tr('\\', '/').strip
-      raw = raw.sub(%r{\A[A-Za-z]:/+}, '')
-      raw = raw.sub(%r{\A/+}, '')
-      return nil if raw.blank?
-
-      segments = raw.split('/').filter_map do |segment|
-        normalized = normalize_segment(segment)
-        normalized.presence
-      end
-      return nil if segments.empty?
-
-      segments.join('/')
-    end
-
-    def uniquify path, source_file_id
-      normalized = normalize_path(path)
-      return normalized if normalized.blank? || source_file_id.blank?
-
-      ext = File.extname(normalized)
-      base = ext.present? ? normalized.delete_suffix(ext) : normalized
-      "#{ base }--#{ source_file_id }#{ ext }"
-    end
-
-    private
-
-    def fallback_filename filename, source_file_id
-      name = normalize_path(filename)
-      return name if name.present?
-      return nil if source_file_id.blank?
-
-      source_file_id.to_s
-    end
-
-    def normalize_segment segment
-      cleaned = segment.to_s.delete("\0").tr('\\/', '_').strip
-      return nil if cleaned.blank? || cleaned == '.'
-      return '__' if cleaned == '..'
-
-      cleaned
-    end
-  end
-end

backend/app/services/material_sync_importer.rb

@@ -1,259 +0,0 @@
-require 'digest'
-
-class MaterialSyncImporter
-  Result = Struct.new(:material, :action, :suppressed, :suppression, keyword_init: true)
-
-  def self.import! attributes
-    new(attributes).import!
-  end
-
-  def initialize attributes
-    @attributes = attributes
-  end
-
-  def import!
-    source = source_attributes
-    key = normalized_source_key(source)
-    raise ArgumentError, 'normalized_source_key is required for material sync' if key.blank?
-
-    suppression = suppression_for(source)
-    if suppression
-      return Result.new(material: nil,
-                        action: :suppressed,
-                        suppressed: true,
-                        suppression:)
-    end
-
-    material =
-        Material
-        .unscoped
-        .find_or_initialize_by(normalized_source_key: key)
-    if unchanged?(material, source)
-      return Result.new(material:,
-                        action: :unchanged,
-                        suppressed: false,
-                        suppression: nil)
-    end
-
-    event_type =
-        if material.new_record?
-          :create
-        elsif material.discarded?
-          :restore
-        else
-          :update
-        end
-    uploaded_blob = uploaded_blob!
-    if @import_block
-      return Result.new(material: nil,
-                        action: :suppressed,
-                        suppressed: true,
-                        suppression: @import_block)
-    end
-
-    Material.transaction do
-      if material.persisted?
-        MaterialVersionRecorder.ensure_snapshot!(material,
-                                                 created_by_user: @attributes[:updated_by_user])
-      end
-      material.assign_attributes(material_attributes_for(material).merge(source))
-      material.discarded_at = nil if material.respond_to?(:discarded_at=)
-      material.file.attach(uploaded_blob) if uploaded_blob
-      material.save!
-      upsert_export_item!(material)
-      MaterialVersionRecorder.record!(material:,
-                                      event_type:,
-                                      created_by_user: @attributes[:updated_by_user])
-    end
-    MaterialThumbnailGenerator.generate!(material)
-
-    Result.new(material:,
-               action: event_type == :create ? :imported : :updated,
-               suppressed: false,
-               suppression: nil)
-  rescue StandardError
-    uploaded_blob&.purge_later
-    raise
-  ensure
-    close_tempfile!
-  end
-
-  private
-
-  def source_attributes
-    { source_kind: @attributes[:source_kind],
-      source_uri: @attributes[:source_uri],
-      source_path: @attributes[:source_path],
-      source_file_id: @attributes[:source_file_id] }
-  end
-
-  def normalized_source_key source
-    MaterialSyncSuppression.normalize_source_key(source_kind: source[:source_kind],
-                                                 source_uri: source[:source_uri],
-                                                 source_path: source[:source_path],
-                                                 source_file_id: source[:source_file_id])
-  end
-
-  def material_attributes_for material
-    attrs =
-        @attributes
-        .except(:source_kind, :source_uri, :source_path, :source_file_id,
-                :file_blob, :file_tempfile, :file_downloader,
-                :filename, :content_type,
-                :file_sha256, :export_path, :profile, :tag, :url)
-
-    if material.new_record?
-      attrs[:tag] = @attributes[:tag] if @attributes.key?(:tag)
-      attrs[:url] = @attributes[:url] if @attributes.key?(:url)
-      return attrs
-    end
-
-    if @attributes.key?(:tag) && @attributes[:tag].present?
-      attrs[:tag] = @attributes[:tag]
-    end
-    if @attributes.key?(:url) && @attributes[:url].present?
-      attrs[:url] = @attributes[:url]
-    end
-
-    attrs
-  end
-
-  def suppression_for source
-    if source[:source_kind] == 'google_drive_file' && source[:source_path].present?
-      return MaterialSyncSuppressionMatcher.match_google_drive_candidate(
-          drive_file_id: source[:source_file_id],
-          relative_path: source[:source_path])
-    end
-
-    MaterialSyncSuppressionMatcher.match(**source)
-  end
-
-  def uploaded_blob!
-    return @attributes[:file_blob] if @attributes[:file_blob]
-
-    tempfile = upload_tempfile
-    return nil unless tempfile
-
-    tempfile.rewind
-    file_sha256 = @attributes[:file_sha256] || Digest::SHA256.file(tempfile.path).hexdigest
-    @attributes[:file_sha256] = file_sha256
-
-    @import_block = MaterialImportBlockMatcher.match_for_sha256(file_sha256)
-    if @import_block
-      tempfile.rewind
-      return nil
-    end
-
-    blob = ActiveStorage::Blob.create_and_upload!(
-        io: tempfile,
-        filename: @attributes[:filename],
-        content_type: @attributes[:content_type])
-    MaterialFileSha256.assign_metadata_sha256!(blob, file_sha256)
-    tempfile.rewind
-    blob
-  end
-
-  def upload_tempfile
-    return @upload_tempfile if defined?(@upload_tempfile)
-
-    @upload_tempfile = @attributes[:file_tempfile]
-    if @upload_tempfile.blank? && @attributes[:file_downloader]
-      @upload_tempfile = @attributes[:file_downloader].call
-    end
-    @upload_tempfile
-  end
-
-  def upsert_export_item! material
-    export_path = resolved_export_path(material)
-    return if export_path.blank?
-
-    item = material.material_export_items.find_or_initialize_by(profile: effective_profile)
-    item.export_path = export_path
-    item.enabled = true
-    item.created_by_user ||= @attributes[:created_by_user]
-    item.save!
-  end
-
-  def export_path_taken_by_other? material, profile, export_path
-    MaterialExportItem
-      .where(profile:, export_path:)
-      .where.not(material_id: material.id)
-      .exists?
-  end
-
-  def close_tempfile!
-    tempfile = upload_tempfile
-    return unless tempfile
-
-    tempfile.close! unless tempfile.closed?
-  rescue StandardError
-    nil
-  end
-
-  def unchanged? material, source
-    return false if material.new_record? || material.discarded?
-    return false unless same_source_attributes?(material, source)
-    return false unless same_export_path?(material)
-    return false unless same_material_attributes?(material)
-
-    same_file_snapshot?(material)
-  end
-
-  def same_source_attributes? material, source
-    material.source_kind == source[:source_kind] \
-      && material.source_uri == source[:source_uri] \
-      && material.source_path == source[:source_path] \
-      && material.source_file_id == source[:source_file_id]
-  end
-
-  def same_export_path? material
-    expected = resolved_export_path(material)
-    current = material.material_export_items.find { |item| item.profile == effective_profile }
-
-    return current.blank? if expected.blank?
-
-    current&.enabled && current.export_path == expected
-  end
-
-  def same_material_attributes? material
-    same_tag_attribute?(material) && same_url_attribute?(material)
-  end
-
-  def same_file_snapshot? material
-    expected_sha256 = @attributes[:file_sha256].to_s.presence
-
-    if expected_sha256.present?
-      return false unless material.file.attached?
-
-      return MaterialFileSha256.metadata_sha256(material.file.blob) == expected_sha256
-    end
-
-    !material.file.attached?
-  end
-
-  def effective_profile
-    @attributes[:profile].presence || 'legacy_drive'
-  end
-
-  def resolved_export_path material
-    export_path = @attributes[:export_path].to_s.strip
-    return export_path if export_path.blank?
-    return export_path unless export_path_taken_by_other?(material, effective_profile, export_path)
-
-    MaterialSyncExportPath.uniquify(export_path, @attributes[:source_file_id])
-  end
-
-  def same_tag_attribute? material
-    return true unless @attributes.key?(:tag)
-    return true if @attributes[:tag].blank?
-
-    material.tag_id == @attributes[:tag].id
-  end
-
-  def same_url_attribute? material
-    return true unless @attributes.key?(:url)
-    return true if @attributes[:url].blank?
-
-    material.url == @attributes[:url]
-  end
-end

backend/app/services/material_sync_runner.rb

@@ -1,251 +0,0 @@
-class MaterialSyncRunner
-  Result = Struct.new(:imported, :updated, :unchanged, :suppressed, :failed,
-                      :errors, keyword_init: true)
-
-  def self.sync_enabled!
-    results = MaterialSyncSource.enabled.order(:id).map { |source| new(source).sync! }
-
-    Result.new(imported: results.sum(&:imported),
-               updated: results.sum(&:updated),
-               unchanged: results.sum(&:unchanged),
-               suppressed: results.sum(&:suppressed),
-               failed: results.sum(&:failed),
-               errors: results.flat_map(&:errors))
-  end
-
-  def initialize source
-    @source = source
-  end
-
-  def sync!
-    result = Result.new(imported: 0, updated: 0, unchanged: 0,
-                        suppressed: 0, failed: 0, errors: [])
-
-    if @source.source_kind == 'google_drive_path'
-      sync_google_drive_path!(result)
-    else
-      candidates.each do |candidate|
-        next if candidate.blank?
-
-        sync_candidate!(candidate, result)
-      end
-    end
-
-    @source.update!(last_synced_at: Time.current)
-    log_result(result)
-    result
-  rescue NotImplementedError, StandardError => e
-    result.failed += 1
-    result.errors << { source_id: @source.id, error: e.message }
-    log_result(result)
-    result
-  end
-
-  private
-
-  def candidates
-    case @source.source_kind
-    when 'uri'
-      [uri_candidate]
-    when 'google_drive_file'
-      [google_drive_file_candidate]
-    when 'legacy_drive_path'
-      raise NotImplementedError, 'legacy_drive_path material sync is not implemented'
-    else
-      raise NotImplementedError, "Unsupported material sync source_kind: #{ @source.source_kind }"
-    end
-  end
-
-  def uri_candidate
-    { source_kind: @source.source_kind,
-      source_uri: @source.source_uri,
-      source_path: @source.source_path,
-      source_file_id: @source.source_file_id,
-      url: @source.source_uri,
-      tag: nil,
-      created_by_user: @source.created_by_user,
-      updated_by_user: @source.updated_by_user || @source.created_by_user }
-  end
-
-  def sync_candidate! candidate, result
-    block = MaterialImportBlockMatcher.match_for_sha256(candidate[:file_sha256])
-    if block
-      result.suppressed += 1
-      Rails.logger.info(
-          material_sync_log(action: 'suppressed',
-                            reason: block.reason,
-                            normalized_source_key: candidate_normalized_source_key(candidate)))
-      return
-    end
-
-    suppression = suppression_for(candidate)
-
-    if suppression
-      result.suppressed += 1
-      Rails.logger.info(
-          material_sync_log(action: 'suppressed',
-                            normalized_source_key: suppression.normalized_source_key))
-      return
-    end
-
-    import = MaterialSyncImporter.import!(candidate)
-    result.public_send("#{ import.action }=", result.public_send(import.action) + 1)
-  rescue StandardError => e
-    result.failed += 1
-    result.errors << { source_id: @source.id,
-                       normalized_source_key: candidate_normalized_source_key(candidate),
-                       error: e.message }
-    Rails.logger.warn(
-        material_sync_log(action: 'failed',
-                          error: e.message,
-                          normalized_source_key: candidate_normalized_source_key(candidate)))
-  ensure
-    close_candidate_tempfile(candidate)
-  end
-
-  def google_drive_path_candidates
-    folder_id = google_drive_folder_id
-    Enumerator.new do |entries|
-      drive_client.each_material_file_under_folder(folder_id).each do |entry|
-        entries << build_google_drive_candidate(entry)
-      end
-    end
-  end
-
-  def sync_google_drive_path! result
-    folder_id = google_drive_folder_id
-    scanned_count = 0
-
-    drive_client.each_material_file_under_folder(folder_id) do |entry|
-      scanned_count += 1
-      sync_candidate!(build_google_drive_candidate(entry), result)
-      log_google_drive_progress(folder_id, scanned_count, result) if progress_log_scan_count?(scanned_count)
-    end
-
-    log_google_drive_progress(folder_id, scanned_count, result, summary: true)
-  end
-
-  def google_drive_file_candidate
-    entry = drive_client.fetch_material_file(google_drive_file_id)
-    return nil unless entry
-
-    build_google_drive_candidate(entry, single_file: true)
-  end
-
-  def build_google_drive_candidate entry, single_file: false
-    relative_path =
-        if single_file
-          nil
-        else
-          entry[:relative_path]
-        end
-    export_path =
-        MaterialSyncExportPath.build(prefix: @source.export_path_prefix,
-                                     relative_path:,
-                                     filename: entry[:name],
-                                     source_file_id: entry[:id])
-
-    { source_kind: 'google_drive_file',
-      source_uri: entry[:web_view_link] || google_drive_file_url(entry[:id]),
-      source_path: relative_path.presence || MaterialSyncExportPath.normalize_path(entry[:name]),
-      source_file_id: entry[:id],
-      filename: entry[:name],
-      content_type: entry[:mime_type],
-      file_downloader: lambda {
-        drive_client.download_to_tempfile(entry[:id], filename: entry[:name])
-      },
-      file_sha256: entry[:sha256_checksum],
-      export_path:,
-      profile: @source.profile,
-      tag: nil,
-      url: nil,
-      created_by_user: @source.created_by_user,
-      updated_by_user: @source.updated_by_user || @source.created_by_user }
-  end
-
-  def candidate_normalized_source_key candidate
-    MaterialSyncSuppression.normalize_source_key(source_kind: candidate[:source_kind],
-                                                 source_uri: candidate[:source_uri],
-                                                 source_path: candidate[:source_path],
-                                                 source_file_id: candidate[:source_file_id])
-  end
-
-  def suppression_for candidate
-    if candidate[:source_kind] == 'google_drive_file' && candidate[:source_path].present?
-      return MaterialSyncSuppressionMatcher.match_google_drive_candidate(
-          drive_file_id: candidate[:source_file_id],
-          relative_path: candidate[:source_path])
-    end
-
-    MaterialSyncSuppressionMatcher.match(source_kind: candidate[:source_kind],
-                                         source_uri: candidate[:source_uri],
-                                         source_path: candidate[:source_path],
-                                         source_file_id: candidate[:source_file_id])
-  end
-
-  def drive_client
-    @drive_client ||= GoogleDrive::ApiClient.new
-  end
-
-  def google_drive_folder_id
-    google_drive_target_id.tap do |id|
-      if id.blank?
-        raise ArgumentError, 'google_drive_path source_file_id or source_uri is required'
-      end
-    end
-  end
-
-  def google_drive_file_id
-    google_drive_target_id.tap do |id|
-      if id.blank?
-        raise ArgumentError, 'google_drive_file source_file_id or source_uri is required'
-      end
-    end
-  end
-
-  def google_drive_target_id
-    @source.source_file_id.presence || drive_client.extract_file_id(@source.source_uri)
-  end
-
-  def google_drive_file_url file_id
-    "https://drive.google.com/file/d/#{ file_id }/view"
-  end
-
-  def close_candidate_tempfile candidate
-    tempfile = candidate[:file_tempfile]
-    return unless tempfile
-
-    tempfile.close! unless tempfile.closed?
-  rescue StandardError
-    nil
-  end
-
-  def log_result result
-    Rails.logger.info(material_sync_log(imported: result.imported,
-                                        updated: result.updated,
-                                        unchanged: result.unchanged,
-                                        suppressed: result.suppressed,
-                                        failed: result.failed))
-  end
-
-  def progress_log_scan_count? scanned_count
-    scanned_count == 1 || (scanned_count % 50).zero?
-  end
-
-  def log_google_drive_progress folder_id, scanned_count, result, summary: false
-    Rails.logger.info(
-        material_sync_log(folder_id:,
-                          scanned_count:,
-                          imported: result.imported,
-                          updated: result.updated,
-                          unchanged: result.unchanged,
-                          suppressed: result.suppressed,
-                          failed: result.failed,
-                          progress: summary ? 'summary' : 'scan'))
-  end
-
-  def material_sync_log fields
-    { material_sync_source_id: @source.id,
-      material_sync_source_name: @source.name }.merge(fields).to_json
-  end
-end

backend/app/services/material_sync_suppression_matcher.rb

@@ -1,68 +0,0 @@
-class MaterialSyncSuppressionMatcher
-  def self.match source_kind:,
-                 source_uri: nil,
-                 drive_path: nil,
-                 drive_file_id: nil,
-                 source_path: nil,
-                 source_file_id: nil
-    key = MaterialSyncSuppression.normalize_source_key(source_kind:,
-                                                       source_uri:,
-                                                       drive_path:,
-                                                       drive_file_id:,
-                                                       source_path:,
-                                                       source_file_id:)
-    return nil if key.blank?
-
-    MaterialSyncSuppression.find_by(normalized_source_key: key)
-  end
-
-  def self.match_google_drive_candidate drive_file_id:, relative_path:
-    normalized_path = validate_relative_path!(relative_path)
-
-    exact = [
-      normalize_key('google_drive_file', drive_file_id),
-      normalize_key('google_drive_path', normalized_path),
-      normalize_key('legacy_drive_path', normalized_path),
-    ].compact
-
-    suppression =
-        MaterialSyncSuppression.find_by(normalized_source_key: exact)
-    return suppression if suppression
-
-    MaterialSyncSuppression
-      .where(source_kind: ['google_drive_path_prefix', 'legacy_drive_path_prefix'])
-      .where('drive_path = :path OR :path LIKE CONCAT(drive_path, "/%")', path: normalized_path)
-      .order(:id)
-      .first
-  end
-
-  def self.suppressed?(...)
-    match(...).present?
-  end
-
-  def self.validate_relative_path! relative_path
-    raw = relative_path.to_s.delete("\0").tr('\\', '/').strip
-    raise ArgumentError, 'relative_path is required' if raw.blank?
-    raise ArgumentError, 'relative_path must be relative' if raw.start_with?('/')
-    raise ArgumentError, 'relative_path must be relative' if raw.match?(/\A[A-Za-z]:\//)
-    if raw.start_with?('My Drive/', 'マイドライブ/')
-      raise ArgumentError, 'relative_path must be relative to source folder'
-    end
-    raise ArgumentError, 'relative_path must not contain //' if raw.include?('//')
-    raise ArgumentError, 'relative_path must not end with /' if raw.end_with?('/')
-
-    parts = raw.split('/')
-    if parts.any? { |part| part.in?(['.', '..']) }
-      raise ArgumentError, 'relative_path must not contain dot segments'
-    end
-
-    raw
-  end
-
-  def self.normalize_key source_kind, value
-    return nil if value.blank?
-
-    MaterialSyncSuppression.normalize_source_key(source_kind:, source_path: value,
-                                                 source_file_id: value)
-  end
-end

backend/app/services/material_sync_suppression_registrar.rb

@@ -1,51 +0,0 @@
-class MaterialSyncSuppressionRegistrar
-  def self.create! attributes, created_by_user:
-    new(attributes, created_by_user:).create!
-  end
-
-  def initialize attributes, created_by_user:
-    @attributes = attributes
-    @created_by_user = created_by_user
-  end
-
-  def create!
-    suppression = nil
-
-    MaterialSyncSuppression.transaction do
-      suppression = MaterialSyncSuppression.create!(
-          @attributes.merge(created_by_user: @created_by_user))
-      discard_existing_materials!(suppression)
-    end
-
-    suppression
-  end
-
-  private
-
-  def discard_existing_materials! suppression
-    matching_materials(suppression).find_each do |material|
-      MaterialVersionRecorder.ensure_snapshot!(material, created_by_user: @created_by_user)
-      material.discard!
-      MaterialVersionRecorder.record!(material:,
-                                      event_type: :discard,
-                                      created_by_user: @created_by_user)
-    end
-  end
-
-  def matching_materials suppression
-    materials = Material.unscoped.kept
-
-    case suppression.source_kind
-    when 'google_drive_path', 'legacy_drive_path'
-      materials.where(source_path: suppression.drive_path)
-    when 'google_drive_path_prefix', 'legacy_drive_path_prefix'
-      path = suppression.drive_path.to_s
-      materials.where(
-          'source_path = :path OR source_path LIKE :prefix',
-          path:,
-          prefix: "#{ path }/%")
-    else
-      materials.where(normalized_source_key: suppression.normalized_source_key)
-    end
-  end
-end

backend/app/services/material_thumbnail_generator.rb

@@ -1,126 +0,0 @@
-# frozen_string_literal: true
-
-require 'mini_magick'
-require 'open3'
-require 'tempfile'
-
-
-class MaterialThumbnailGenerator
-  SIZE = '180x180'
-
-  class << self
-    def generate! material
-      new(material).generate!
-    end
-  end
-
-  def initialize material
-    @material = material
-    @ffmpeg_stderr = []
-  end
-
-  def generate!
-    return log_result(:no_file) unless @material.file.attached?
-    return log_result(:unsupported_content_type) unless image? || video?
-
-    @material.file.blob.open do |file|
-      thumbnail = image? ? image_thumbnail(file.path) : video_thumbnail(file.path)
-      return log_result(:generation_failed) unless thumbnail
-
-      return attach_thumbnail(thumbnail)
-    end
-  rescue ActiveStorage::FileNotFoundError => e
-    log_result(:file_not_found, error: e)
-  rescue MiniMagick::Error => e
-    log_result(:mini_magick_error, error: e)
-  rescue ArgumentError, StandardError => e
-    log_result(:generation_failed, error: e)
-  end
-
-  private
-
-  def image? = content_type.start_with?('image/')
-
-  def video? = content_type.start_with?('video/')
-
-  def content_type
-    return nil unless @material.file.attached?
-
-    @material.file.blob.content_type.to_s
-  end
-
-  def image_thumbnail path
-    image = MiniMagick::Image.open(path)
-    image.resize(SIZE)
-    image.format('jpg')
-    image
-  end
-
-  def video_thumbnail path
-    [1, 0].each do |seconds|
-      tempfile = Tempfile.new(['material-thumbnail', '.jpg'])
-      tempfile.close
-      ok = extract_video_frame(path, tempfile.path, seconds)
-      next unless ok && File.size?(tempfile.path)
-
-      return image_thumbnail(tempfile.path)
-    ensure
-      tempfile&.unlink
-    end
-
-    nil
-  end
-
-  def extract_video_frame input_path, output_path, seconds
-    _stdout, stderr, status =
-        Open3.capture3('ffmpeg',
-                       '-y',
-                       '-ss', seconds.to_s,
-                       '-i', input_path,
-                       '-frames:v', '1',
-                       '-f', 'image2',
-                       output_path)
-    @ffmpeg_stderr << stderr if stderr.present?
-    status.success?
-  rescue Errno::ENOENT => e
-    @ffmpeg_stderr << "ffmpeg unavailable: #{ e.message }"
-    false
-  end
-
-  def attach_thumbnail image
-    blob = nil
-    File.open(image.path) do |io|
-      blob = ActiveStorage::Blob.create_and_upload!(
-          io:,
-          filename: 'material-thumbnail.jpg',
-          content_type: 'image/jpeg')
-    end
-    @material.thumbnail.attach(blob)
-    log_result(:attached)
-  rescue StandardError => e
-    blob&.purge_later
-    log_result(:attach_failed, error: e)
-  end
-
-  def log_result result, error: nil
-    log_payload = { material_id: @material.id,
-                    file_blob_id: file_blob_id,
-                    content_type:,
-                    result:,
-                    error_class: error&.class&.name,
-                    error_message: error&.message,
-                    ffmpeg_stderr: @ffmpeg_stderr.join("\n").presence }
-    if [:attached, :no_file, :unsupported_content_type].include?(result)
-      Rails.logger.info("Material thumbnail generation: #{ log_payload.to_json }")
-    else
-      Rails.logger.warn("Material thumbnail generation: #{ log_payload.to_json }")
-    end
-    result
-  end
-
-  def file_blob_id
-    return nil unless @material.file.attached?
-
-    @material.file.blob.id
-  end
-end

backend/app/services/material_version_recorder.rb

@@ -1,73 +0,0 @@
-class MaterialVersionRecorder < VersionRecorder
-  EVENT_TYPES = ['create', 'update', 'discard', 'restore'].freeze
-
-  def self.record! material:, event_type:, created_by_user:, file_snapshot: nil
-    new(material:, event_type:, created_by_user:, file_snapshot:).record!
-  end
-
-  def initialize material:, event_type:, created_by_user:, file_snapshot: nil
-    @file_snapshot = file_snapshot
-
-    super(record: material, event_type:, created_by_user:)
-  end
-
-  def self.ensure_snapshot! material, created_by_user:
-    return if material.material_versions.exists?
-
-    record!(material:, event_type: :create,
-            created_by_user: material.created_by_user || created_by_user)
-  end
-
-  private
-
-  def version_class = MaterialVersion
-  def version_association = :material_versions
-  def record_key = :material
-
-  def snapshot_attributes
-    blob = @record.file.attached? ? @record.file.blob : nil
-    file_snapshot = build_file_snapshot(blob)
-
-    { url: @record.url,
-      parent: @record.parent,
-      tag: @record.tag,
-      tag_name: @record.tag&.name,
-      tag_category: @record.tag&.category,
-      source_kind: @record.source_kind,
-      source_uri: @record.source_uri,
-      source_path: @record.source_path,
-      source_file_id: @record.source_file_id,
-      normalized_source_key: @record.normalized_source_key,
-      export_paths_json: @record.snapshot_export_paths,
-      discarded_at: @record.discarded_at,
-      file_blob_id: file_snapshot[:file_blob_id],
-      file_filename: file_snapshot[:file_filename],
-      file_content_type: file_snapshot[:file_content_type],
-      file_byte_size: file_snapshot[:file_byte_size],
-      file_checksum: file_snapshot[:file_checksum],
-      file_sha256: file_snapshot[:file_sha256] }
-  end
-
-  def build_file_snapshot blob
-    return @file_snapshot if @file_snapshot
-    return empty_file_snapshot unless blob
-
-    { file_blob_id: blob.id,
-      file_filename: blob.filename.to_s,
-      file_content_type: blob.content_type,
-      file_byte_size: blob.byte_size,
-      file_checksum: blob.checksum,
-      file_sha256: MaterialFileSha256.metadata_sha256(blob) }
-  end
-
-  def empty_file_snapshot
-    { file_blob_id: nil,
-      file_filename: nil,
-      file_content_type: nil,
-      file_byte_size: nil,
-      file_checksum: nil,
-      file_sha256: nil }
-  end
-
-  def event_types = self.class::EVENT_TYPES
-end

backend/app/services/material_zip_exporter.rb

@@ -1,148 +0,0 @@
-require 'stringio'
-require 'zlib'
-
-# Initial implementation keeps every file payload and the final ZIP in memory.
-# Keep this service boundary stable so job/cached export paths can replace it later.
-class MaterialZipExporter
-  Entry = Struct.new(:path, :data, :mtime, keyword_init: true)
-  MissingFile = Struct.new(:material_id, :export_path, :blob_id, :filename, keyword_init: true)
-
-  class EmptyExportError < StandardError; end
-  class DuplicatePathError < StandardError; end
-  class MissingFileError < StandardError
-    attr_reader :missing_files
-
-    def initialize missing_files
-      @missing_files = missing_files
-
-      super("Missing files: #{missing_files.map(&:export_path).join(', ')}")
-    end
-  end
-
-  def initialize profile: 'legacy_drive', tag_id: nil
-    @profile = profile.presence || 'legacy_drive'
-    @tag_id = tag_id.presence
-  end
-
-  def export
-    entries = build_entries
-    raise EmptyExportError if entries.empty?
-
-    ZipWriter.write(entries)
-  end
-
-  private
-
-  def build_entries
-    rows = MaterialExportItem
-           .enabled
-           .includes(material: { file_attachment: :blob })
-           .joins(:material)
-           .merge(Material.kept)
-           .where(profile: @profile)
-           .order(:export_path)
-
-    rows = rows.where(materials: { tag_id: @tag_id }) if @tag_id
-
-    missing_files = []
-
-    entries = rows.filter_map do |item|
-      material = item.material
-      next unless material.file.attached?
-
-      data = download_blob(item, missing_files)
-      next unless data
-
-      Entry.new(path: item.export_path,
-                data:,
-                mtime: material.updated_at || Time.current)
-    end
-
-    raise MissingFileError.new(missing_files) if missing_files.any?
-
-    paths = entries.map(&:path)
-    duplicated = paths.find { |path| paths.count(path) > 1 }
-    raise DuplicatePathError, duplicated if duplicated
-
-    entries
-  end
-
-  def download_blob item, missing_files
-    blob = item.material.file.blob
-
-    blob.download
-  rescue ActiveStorage::FileNotFoundError
-    missing_files << MissingFile.new(
-        material_id: item.material_id,
-        export_path: item.export_path,
-        blob_id: blob.id,
-        filename: blob.filename.to_s,
-    )
-    nil
-  end
-
-  class ZipWriter
-    VERSION_NEEDED = 20
-    GP_FLAG = 0x0800
-    COMPRESSION_STORE = 0
-
-    def self.write entries
-      new(entries).write
-    end
-
-    def initialize entries
-      @entries = entries
-      @central_directory = []
-    end
-
-    def write
-      io = StringIO.new(''.b)
-
-      @entries.each do |entry|
-        write_entry(io, entry)
-      end
-
-      central_start = io.pos
-      @central_directory.each { |header| io.write(header) }
-      central_size = io.pos - central_start
-
-      io.write([0x06054b50, 0, 0, @entries.size, @entries.size,
-                central_size, central_start, 0].pack('VvvvvVVv'))
-      io.string
-    end
-
-    private
-
-    def write_entry io, entry
-      path = entry.path.b
-      data = entry.data.b
-      crc32 = Zlib.crc32(data)
-      dos_time, dos_date = dos_timestamp(entry.mtime)
-      offset = io.pos
-
-      local_header = [0x04034b50, VERSION_NEEDED, GP_FLAG, COMPRESSION_STORE,
-                      dos_time, dos_date, crc32, data.bytesize, data.bytesize,
-                      path.bytesize, 0].pack('VvvvvvVVVvv')
-
-      io.write(local_header)
-      io.write(path)
-      io.write(data)
-
-      @central_directory << central_header(path:, crc32:, size: data.bytesize,
-                                           dos_time:, dos_date:, offset:)
-    end
-
-    def central_header path:, crc32:, size:, dos_time:, dos_date:, offset:
-      [0x02014b50, VERSION_NEEDED, VERSION_NEEDED, GP_FLAG, COMPRESSION_STORE,
-       dos_time, dos_date, crc32, size, size, path.bytesize, 0, 0, 0, 0, 0,
-       offset].pack('VvvvvvvVVVvvvvvVV') + path
-    end
-
-    def dos_timestamp time
-      local = time.to_time
-      dos_time = (local.hour << 11) | (local.min << 5) | (local.sec / 2)
-      dos_date = ((local.year - 1980) << 9) | (local.month << 5) | local.day
-      [dos_time, dos_date]
-    end
-  end
-end

backend/app/services/post_bulk_creator.rb

@@ -1,202 +0,0 @@
-class PostBulkCreator
-  def initialize actor:, posts:, thumbnails:, host: nil
-    @actor_id = actor.id
-    @posts = posts
-    @thumbnails = thumbnails
-    @host = host
-  end
-
-  def run
-    results = Array.new(@posts.length)
-    mutex = Mutex.new
-    next_index = 0
-
-    workers = Array.new(2) do
-      Thread.new do
-        Rails.application.executor.wrap do
-          ActiveRecord::Base.connection_pool.with_connection do
-            actor = User.find(@actor_id)
-            loop do
-              index = nil
-              begin
-                index = mutex.synchronize do
-                  current = next_index
-                  next_index += 1
-                  current
-                end
-                break if index >= @posts.length
-
-                attributes = @posts[index]
-                results[index] = create_row(actor, attributes, index)
-              rescue StandardError => e
-                Rails.logger.error(
-                    "post_bulk_creator_worker_failure #{ { error: e.class.name,
-                                                          message: e.message,
-                                                          index: }.to_json }")
-                results[index] = {
-                    status: 'failed',
-                    recoverable: false,
-                    errors: { base: ['登録中にエラーが発生しました．'] },
-                    base_errors: [] }
-              end
-            end
-          end
-        end
-      end
-    end
-    workers.each(&:join)
-
-    results.each_index do |index|
-      next if results[index].present?
-
-      results[index] = {
-          status: 'failed',
-          recoverable: false,
-          errors: { base: ['登録中にエラーが発生しました．'] },
-          base_errors: [] }
-    end
-
-    { results: }
-  end
-
-  private
-
-  def create_row actor, attributes, index
-    preflight =
-        PostCreatePreflight.new(
-            attributes: attributes,
-            thumbnail: thumbnail_for(index, attributes),
-            host: @host).run
-    if preflight[:existing_post_id].present?
-      return {
-          status: 'skipped',
-          existing_post_id: preflight[:existing_post_id],
-          existing_post: preflight[:existing_post] }
-    end
-
-    post = PostCreator.new(
-        actor: actor,
-        attributes: normalised_attributes(attributes, preflight, index)).create!
-    result = {
-        status: 'created',
-        post: { id: post.id } }
-    result[:field_warnings] = preflight[:field_warnings] if preflight[:field_warnings].present?
-    result[:base_warnings] = preflight[:base_warnings] if preflight[:base_warnings].present?
-    result
-  rescue PostCreatePreflight::ValidationFailed => e
-    {
-        status: 'failed',
-        recoverable: true,
-        errors: e.fields,
-        base_errors: e.base_errors }
-  rescue ActiveRecord::RecordInvalid => e
-    existing_post = existing_post_for_race(attributes, e.record)
-    if existing_post.present?
-      return {
-          status: 'skipped',
-          existing_post_id: existing_post[:id],
-          existing_post: existing_post }
-    end
-
-    {
-        status: 'failed',
-        recoverable: true,
-        errors: e.record.errors.to_hash,
-        base_errors: e.record.errors[:base] }
-  rescue ActiveRecord::RecordNotUnique => e
-    if e.message.include?('index_posts_on_url')
-      existing_post = existing_post_for_race(attributes)
-      return {
-          status: 'skipped',
-          existing_post_id: existing_post[:id],
-          existing_post: existing_post } if existing_post.present?
-    end
-
-    Rails.logger.error(
-        "post_bulk_creator_record_not_unique #{ { error: e.class.name,
-                                                 message: e.message }.to_json }")
-    {
-        status: 'failed',
-        recoverable: false,
-        errors: { base: ['登録中にエラーが発生しました．'] },
-        base_errors: [] }
-  rescue Tag::NicoTagNormalisationError
-    {
-        status: 'failed',
-        recoverable: true,
-        errors: { tags: ['ニコニコ・タグは直接指定できません．'] },
-        base_errors: [] }
-  rescue Tag::DeprecatedTagNormalisationError
-    {
-        status: 'failed',
-        recoverable: true,
-        errors: { tags: ['廃止済みタグは付与できません．'] },
-        base_errors: [] }
-  rescue PostCreator::VideoMsParseError
-    {
-        status: 'failed',
-        recoverable: true,
-        errors: { video_ms: ['動画時間の記法が不正です．'] },
-        base_errors: [] }
-  rescue Post::RemoteThumbnailFetchFailed
-    {
-        status: 'failed',
-        recoverable: true,
-        errors: { thumbnail_base: ['サムネイル画像の取得に失敗しました．'] },
-        base_errors: [] }
-  rescue ArgumentError => e
-    {
-        status: 'failed',
-        recoverable: true,
-        errors: { base: [e.message] },
-        base_errors: [] }
-  rescue StandardError => e
-    Rails.logger.error(
-        "post_bulk_creator_failure #{ { error: e.class.name,
-                                        message: e.message }.to_json }")
-    {
-        status: 'failed',
-        recoverable: false,
-        errors: { base: ['登録中にエラーが発生しました．'] },
-        base_errors: [] }
-  end
-
-  def normalised_attributes attributes, preflight, index
-    {
-        url: preflight[:url],
-        title: preflight[:title],
-        thumbnail_base: preflight[:thumbnail_base],
-        thumbnail: thumbnail_for(index, attributes),
-        tags: preflight[:tags],
-        parent_post_ids: preflight[:parent_post_ids],
-        original_created_from: preflight[:original_created_from],
-        original_created_before: preflight[:original_created_before],
-        duration: preflight[:duration],
-        video_ms: preflight[:video_ms],
-        direct_tag_specs: preflight[:direct_tag_specs],
-        default_tag_specs: preflight[:default_tag_specs],
-        snapshot_tag_specs: preflight[:snapshot_tag_specs],
-        post_tag_specs: preflight[:post_tag_specs],
-        tag_sections: preflight[:tag_sections],
-        normalised_parent_post_ids: preflight[:normalised_parent_post_ids] }
-  end
-
-  def thumbnail_for index, attributes
-    return nil if attributes['thumbnail_base'].present? || attributes[:thumbnail_base].present?
-
-    @thumbnails[index]
-  end
-
-  def existing_post_for_race attributes, record = nil
-    return nil if record.present? && !(record.errors.of_kind?(:url, :taken))
-
-    normal_url = PostUrlNormaliser.normalise(attributes['url'] || attributes[:url])
-    return nil if normal_url.blank?
-
-    compact_existing_post(Post.with_attached_thumbnail.find_by(url: normal_url))
-  end
-
-  def compact_existing_post post
-    PostCompactRepr.base(post, host: @host)
-  end
-end

backend/app/services/post_create_plan.rb

@@ -1,269 +0,0 @@
-class PostCreatePlan
-  VIDEO_TAG_NAME = '動画'.freeze
-  TAGME_TAG_NAME = 'タグ希望'.freeze
-  NO_DEERJIKIST_TAG_NAME = 'ニジラー情報不詳'.freeze
-
-  def initialize attributes:
-    @attributes = attributes.symbolize_keys
-    @existing_tags_by_name = nil
-  end
-
-  def build!
-    direct_tag_specs, tag_sections = parse_direct_tag_specs
-    default_tag_specs = build_default_tag_specs(direct_tag_specs)
-    snapshot_tag_specs = merge_tag_specs(direct_tag_specs + default_tag_specs)
-    preload_existing_tags_by_name!(snapshot_tag_specs.map { _1[:name] })
-    validate_new_tag_specs!(snapshot_tag_specs)
-    post_tag_specs = expand_parent_tag_specs(snapshot_tag_specs)
-    video_ms = normalise_video_ms(snapshot_tag_specs)
-    validate_video_sections!(video_ms, tag_sections)
-    parent_post_ids = normalise_parent_post_ids
-    validate_parent_post_ids!(parent_post_ids)
-
-    {
-        url: @attributes[:url],
-        title: @attributes[:title].to_s,
-        thumbnail_base: @attributes[:thumbnail_base].presence,
-        original_created_from: @attributes[:original_created_from].presence,
-        original_created_before: @attributes[:original_created_before].presence,
-        tags: serialised_tags(direct_tag_specs, tag_sections),
-        display_tags: display_tags(direct_tag_specs, tag_sections),
-        duration: @attributes[:duration].to_s,
-        video_ms: video_ms,
-        parent_post_ids: parent_post_ids.join(' '),
-        direct_tag_specs: direct_tag_specs,
-        default_tag_specs: default_tag_specs,
-        snapshot_tag_specs: snapshot_tag_specs,
-        post_tag_specs: post_tag_specs,
-        tag_sections: tag_sections,
-        normalised_parent_post_ids: parent_post_ids }
-  end
-
-  private
-
-  def tag_names = @attributes[:tags].to_s.split
-
-  def parse_direct_tag_specs
-    tag_sections = { }
-    direct_tag_specs = []
-
-    tag_names.each do |raw_name|
-      tag_name, category, sections = parse_raw_tag_name(raw_name)
-      existing_tag = existing_tags_by_name[tag_name]
-      raise Tag::NicoTagNormalisationError if existing_tag&.nico?
-      raise Tag::DeprecatedTagNormalisationError, [existing_tag.name] if existing_tag&.deprecated?
-
-      direct_tag_specs << {
-          name: tag_name,
-          category: (category || existing_tag&.category || 'general').to_sym }
-      if sections.present?
-        tag_sections[tag_name] ||= []
-        tag_sections[tag_name].concat(sections)
-        tag_sections[tag_name] = Tag.merge_section_ranges(tag_sections[tag_name])
-        tag_sections.delete(tag_name) if tag_sections[tag_name] == [[0, nil]]
-      end
-    end
-
-    [merge_tag_specs(direct_tag_specs), tag_sections]
-  end
-
-  def parse_raw_tag_name raw_name
-    name = raw_name.to_s
-    prefix, category =
-        Tag::CATEGORY_PREFIXES.find {
-          name.downcase.start_with?(_1[0])
-        } || ['', nil]
-    name = name.sub(/\A#{ prefix }/i, '')
-
-    sections = []
-    while (match = name.match(/\A(\S*?)\[([^\[\]\s]*)-([^\[\]\s]*)\](\S*)\z/))
-      name = "#{ match[1] }#{ match[4] }"
-      next if match[2].empty? && match[3].empty?
-
-      sections << Tag.normalise_section_range!(
-          begin_raw: match[2],
-          end_raw: match[3],
-          tag_name: name)
-    end
-    raise Tag::SectionLiteralParseError.new(raw_name, raw_name) if name.include?('[') || name.include?(']')
-
-    [resolved_tag_name(name), category&.to_sym, sections]
-  end
-
-  def build_default_tag_specs direct_tag_specs
-    default_tag_specs = []
-    if direct_tag_specs.length < 10 && direct_tag_specs.none? { _1[:name] == TAGME_TAG_NAME }
-      default_tag_specs << {
-          name: TAGME_TAG_NAME,
-          category: :meta }
-    end
-    if direct_tag_specs.none? { deerjikist_tag_spec?(_1) }
-      default_tag_specs << {
-          name: NO_DEERJIKIST_TAG_NAME,
-          category: :meta }
-    end
-
-    default_tag_specs
-  end
-
-  def validate_new_tag_specs! specs
-    Array(specs).each do |spec|
-      next if existing_tags_by_name.key?(spec[:name])
-
-      validate_new_tag_spec!(spec)
-    end
-  end
-
-  def validate_new_tag_spec! spec
-    tag_name = TagName.new(name: spec[:name])
-    tag = Tag.new(category: spec[:category], tag_name:)
-    return if tag_name.valid? && tag.valid?
-
-    post = Post.new
-    tag_name.errors[:name].each do |message|
-      post.errors.add :tags, "#{ spec[:name] }: #{ message }"
-    end
-    tag.errors.each do |error|
-      next if error.attribute == :tag_name
-
-      post.errors.add :tags, "#{ spec[:name] }: #{ error.message }"
-    end
-    raise ActiveRecord::RecordInvalid, post
-  end
-
-  def expand_parent_tag_specs snapshot_tag_specs
-    existing_snapshot_tags = snapshot_tag_specs.filter_map { existing_tags_by_name[_1[:name]] }
-    expanded_parent_specs =
-        Tag.expand_parent_tags(existing_snapshot_tags)
-           .reject(&:deprecated?)
-           .map { |tag|
-             {
-                 name: tag.name,
-                 category: tag.category.to_sym } }
-    merge_tag_specs(snapshot_tag_specs + expanded_parent_specs)
-  end
-
-  def merge_tag_specs specs
-    specs.each_with_object({ }) do |spec, merged|
-      merged[spec[:name]] =
-          if merged.key?(spec[:name]) && merged[spec[:name]][:category] != :general
-            merged[spec[:name]]
-          else
-            {
-                name: spec[:name],
-                category: spec[:category] }
-          end
-    end.values.sort_by { _1[:name] }
-  end
-
-  def existing_tags_by_name
-    @existing_tags_by_name ||= begin
-      names = tag_names.map { canonical_tag_name_without_sections(_1) }.uniq
-      Tag.joins(:tag_name).where(tag_names: { name: names }).index_by(&:name)
-    end
-  end
-
-  def preload_existing_tags_by_name! names
-    wanted_names = Array(names).map { _1.to_s }.reject(&:blank?).uniq
-    missing_names = wanted_names - existing_tags_by_name.keys
-    return if missing_names.empty?
-
-    existing_tags_by_name.merge!(
-        Tag.joins(:tag_name)
-           .where(tag_names: { name: missing_names })
-           .index_by(&:name))
-  end
-
-  def canonical_tag_name_without_sections raw_name
-    name, = parse_raw_tag_name(raw_name)
-    name
-  end
-
-  def deerjikist_tag_spec? spec
-    return true if spec[:category] == :deerjikist
-
-    existing_tags_by_name[spec[:name]]&.deerjikist?
-  end
-
-  def normalise_parent_post_ids
-    Array(@attributes[:parent_post_ids]).flat_map { _1.to_s.split }.map { |token|
-      id = Integer(token, exception: false)
-      raise ArgumentError, "親投稿 Id. が不正です: #{ token }" if id.nil? || id <= 0
-
-      id
-    }.uniq.sort
-  end
-
-  def validate_parent_post_ids! ids
-    missing = ids - Post.where(id: ids).pluck(:id)
-    raise ArgumentError, "存在しない親投稿 Id. があります: #{ missing.join(' ') }" if missing.present?
-  end
-
-  def serialised_tags direct_tag_specs, tag_sections
-    direct_tag_specs.map { |spec|
-      "#{ spec[:name] }#{ tag_sections[spec[:name]].to_a.map { section_literal(_1) }.join }"
-    }.sort.join(' ')
-  end
-
-  def display_tags direct_tag_specs, tag_sections
-    direct_tag_specs.map { |spec|
-      {
-          name: spec[:name],
-          category: spec[:category].to_s,
-          section_literals: tag_sections[spec[:name]].to_a.map { section_literal(_1) } }
-    }.sort_by { _1[:name] }
-  end
-
-  def section_literal range
-    begin_ms, end_ms = range
-    "[#{ Post.ms_to_time(begin_ms) }-#{ end_ms ? Post.ms_to_time(end_ms) : '' }]"
-  end
-
-  def normalise_video_ms snapshot_tag_specs
-    return nil unless snapshot_tag_specs.any? { _1[:name] == VIDEO_TAG_NAME }
-
-    video_ms = @attributes[:video_ms]
-    if video_ms.present?
-      value = Integer(video_ms, exception: false)
-      raise PostCreator::VideoMsParseError unless value&.positive?
-
-      return value
-    end
-
-    duration = @attributes[:duration]
-    return nil if duration.blank?
-
-    value = Tag.time_to_ms!(duration.to_s, tag_name: '動画時間')
-    raise PostCreator::VideoMsParseError unless value.positive?
-
-    value
-  rescue Tag::SectionLiteralParseError
-    raise PostCreator::VideoMsParseError
-  end
-
-  def validate_video_sections! video_ms, tag_sections
-    return unless video_ms
-
-    tag_sections.each_value do |ranges|
-      ranges.each do |begin_ms, end_ms|
-        if begin_ms >= video_ms
-          post = Post.new
-          post.errors.add :video_ms, 'タグ区間の開始が動画時間以上です．'
-          raise ActiveRecord::RecordInvalid, post
-        end
-        if end_ms && end_ms > video_ms
-          post = Post.new
-          post.errors.add :video_ms, 'タグ区間の終端が動画時間を超えてゐます．'
-          raise ActiveRecord::RecordInvalid, post
-        end
-      end
-    end
-  end
-
-  def resolved_tag_name name
-    tag_name = TagName.includes(:canonical).find_by(name:)
-    return name if tag_name.nil?
-
-    (tag_name.canonical || tag_name).name
-  end
-end

backend/app/services/post_create_preflight.rb

@@ -1,141 +0,0 @@
-class PostCreatePreflight
-  class ValidationFailed < StandardError
-    attr_reader :fields, :base_errors
-
-    def initialize fields: { }, base_errors: []
-      super('入力内容を確認してください．')
-      @fields = fields
-      @base_errors = base_errors
-    end
-  end
-
-  def initialize attributes:, thumbnail: nil, host: nil
-    @attributes = attributes.symbolize_keys
-    @thumbnail = thumbnail
-    @host = host
-  end
-
-  def run
-    preview = PostImportPreviewer.new.preview_rows(
-        rows: [preview_row],
-        fetch_metadata: false).first
-    if preview[:existing_post_id].present?
-      return {
-          url: preview[:url],
-          title: preview[:attributes]['title'],
-          thumbnail_base: preview[:attributes]['thumbnail_base'],
-          tags: preview[:attributes]['tags'],
-          parent_post_ids: preview[:attributes]['parent_post_ids'],
-          original_created_from: preview[:attributes]['original_created_from'],
-          original_created_before: preview[:attributes]['original_created_before'],
-          duration: preview[:attributes]['duration'],
-          video_ms: preview[:attributes]['video_ms'],
-          display_tags: preview[:display_tags] || [],
-          field_warnings: final_field_warnings(preview[:field_warnings] || { }),
-          base_warnings: preview[:base_warnings],
-          existing_post_id: preview[:existing_post_id],
-          existing_post: existing_post_compact(preview[:existing_post_id]) }
-    end
-
-    if preview[:validation_errors].present?
-      raise ValidationFailed.new(fields: preview[:validation_errors])
-    end
-
-    validate_thumbnail_upload!
-
-    plan = PostCreatePlan.new(
-        attributes: {
-            url: preview[:url],
-            title: preview[:attributes]['title'],
-            thumbnail_base: preview[:attributes]['thumbnail_base'],
-            tags: preview[:attributes]['tags'],
-            parent_post_ids: preview[:attributes]['parent_post_ids'],
-            original_created_from: preview[:attributes]['original_created_from'],
-            original_created_before: preview[:attributes]['original_created_before'],
-            duration: preview[:attributes]['duration'],
-            video_ms: preview[:attributes]['video_ms'] }).build!
-
-    {
-        url: plan[:url],
-        title: plan[:title],
-        thumbnail_base: plan[:thumbnail_base],
-        tags: plan[:tags],
-        parent_post_ids: plan[:parent_post_ids],
-        original_created_from: plan[:original_created_from],
-        original_created_before: plan[:original_created_before],
-        duration: plan[:duration],
-        video_ms: plan[:video_ms],
-        display_tags: plan[:display_tags],
-        direct_tag_specs: plan[:direct_tag_specs],
-        default_tag_specs: plan[:default_tag_specs],
-        snapshot_tag_specs: plan[:snapshot_tag_specs],
-        post_tag_specs: plan[:post_tag_specs],
-        tag_sections: plan[:tag_sections],
-        normalised_parent_post_ids: plan[:normalised_parent_post_ids],
-        field_warnings: final_field_warnings(preview[:field_warnings] || { }),
-        base_warnings: preview[:base_warnings],
-        existing_post_id: preview[:existing_post_id],
-        existing_post: existing_post_compact(preview[:existing_post_id]) }
-  end
-
-  private
-
-  def preview_row
-    {
-        source_row: 1,
-        url: @attributes[:url].to_s,
-        attributes: {
-            'title' => @attributes[:title].to_s,
-            'thumbnail_base' => @attributes[:thumbnail_base].to_s,
-            'original_created_from' => @attributes[:original_created_from].to_s,
-            'original_created_before' => @attributes[:original_created_before].to_s,
-            'duration' => @attributes[:duration].to_s,
-            'video_ms' => @attributes[:video_ms],
-            'tags' => @attributes[:tags].to_s,
-            'parent_post_ids' => parent_post_ids_text },
-        provenance: {
-            'url' => 'manual',
-            'title' => 'manual',
-            'thumbnail_base' => 'manual',
-            'original_created_from' => 'manual',
-            'original_created_before' => 'manual',
-            'duration' => 'manual',
-            'video_ms' => 'manual',
-            'tags' => 'manual',
-            'parent_post_ids' => 'manual' },
-        tag_sources: {
-            'automatic' => '',
-            'manual' => @attributes[:tags].to_s } }
-  end
-
-  def parent_post_ids_text
-    Array(@attributes[:parent_post_ids]).flat_map { _1.to_s.split }.join(' ')
-  end
-
-  def validate_thumbnail_upload!
-    return if @attributes[:thumbnail_base].present?
-    return if @thumbnail.blank?
-
-    PostThumbnailUploadValidator.validate!(@thumbnail)
-  rescue PostThumbnailUploadValidator::InvalidUpload => e
-    raise ValidationFailed.new(fields: { thumbnail: [e.message] })
-  end
-
-  def existing_post_compact post_id
-    return nil if post_id.blank?
-
-    post = Post.with_attached_thumbnail.find_by(id: post_id)
-    PostCompactRepr.base(post, host: @host)
-  end
-
-  def final_field_warnings field_warnings
-    thumbnail_warnings = (field_warnings['thumbnail_base'] || []).reject { _1 == 'サムネールなし' }
-    if @attributes[:thumbnail_base].blank? && @thumbnail.blank?
-      thumbnail_warnings = (thumbnail_warnings + ['サムネールなし']).uniq
-    end
-
-    next_warnings = field_warnings.except('thumbnail_base')
-    next_warnings['thumbnail_base'] = thumbnail_warnings if thumbnail_warnings.present?
-    next_warnings
-  end
-end

backend/app/services/post_creator.rb

@@ -1,154 +0,0 @@
-class PostCreator
-  class VideoMsParseError < ArgumentError; end
-
-  attr_reader :field_warnings
-
-  def initialize actor:, attributes:
-    @actor = actor
-    @attributes = attributes.symbolize_keys
-    @field_warnings = { }
-  end
-
-  def create!
-    thumbnail_attachment = prepare_thumbnail_attachment
-    post = Post.new(title: @attributes[:title].presence,
-                    url: @attributes[:url],
-                    thumbnail_base: @attributes[:thumbnail_base].presence,
-                    uploaded_user: @actor,
-                    original_created_from: @attributes[:original_created_from].presence,
-                    original_created_before: @attributes[:original_created_before].presence)
-
-    ApplicationRecord.transaction do
-      post.save!
-      post.thumbnail.attach(thumbnail_attachment) if thumbnail_attachment.present?
-      snapshot_tags = planned_snapshot_tags
-      post_tags = planned_post_tags
-      sections = planned_sections
-      TagVersioning.record_tag_snapshots!(snapshot_tags, created_by_user: @actor)
-      post.video_ms = planned_video_ms
-      post.save!
-      sync_post_tags!(post, post_tags, sections)
-      sync_parent_posts!(post, planned_parent_post_ids)
-      PostVersionRecorder.record!(post:, event_type: :create, created_by_user: @actor)
-    end
-    post
-  rescue StandardError
-    post&.thumbnail&.purge if post&.thumbnail&.attached?
-    raise
-  end
-
-  private
-
-  def prepare_thumbnail_attachment
-    PostThumbnailAttachmentBuilder.build(
-        thumbnail: @attributes[:thumbnail],
-        thumbnail_base: @attributes[:thumbnail_base].presence)
-  end
-
-  def planned_snapshot_tags = planned_create_attributes[:snapshot_tags]
-
-  def planned_post_tags = planned_create_attributes[:post_tags]
-
-  def planned_sections = planned_create_attributes[:tag_sections]
-
-  def planned_parent_post_ids = planned_create_attributes[:normalised_parent_post_ids]
-
-  def planned_video_ms
-    planned_create_attributes[:video_ms]
-  end
-
-  def planned_create_attributes
-    @planned_create_attributes ||= begin
-      if @attributes.key?(:snapshot_tag_specs)
-        snapshot_tags = materialise_tags(@attributes[:snapshot_tag_specs] || [])
-        post_tags = materialise_tags(@attributes[:post_tag_specs] || [])
-        {
-            snapshot_tags: snapshot_tags,
-            post_tags: post_tags,
-            tag_sections: materialise_sections(
-                @attributes[:tag_sections] || { },
-                snapshot_tags,
-                post_tags),
-            normalised_parent_post_ids: @attributes[:normalised_parent_post_ids] || [],
-            video_ms: @attributes[:video_ms] }
-      else
-        build_materialised_plan
-      end
-    end
-  end
-
-  def build_materialised_plan
-    plan = PostCreatePlan.new(attributes: @attributes).build!
-    snapshot_tags = materialise_tags(plan[:snapshot_tag_specs] || [])
-    post_tags = materialise_tags(plan[:post_tag_specs] || [])
-    {
-        snapshot_tags: snapshot_tags,
-        post_tags: post_tags,
-        tag_sections: materialise_sections(
-            plan[:tag_sections] || { },
-            snapshot_tags,
-            post_tags),
-        normalised_parent_post_ids: plan[:normalised_parent_post_ids] || [],
-        video_ms: plan[:video_ms] }
-  end
-
-  def materialise_tags specs
-    Array(specs).each_with_object({ }) do |spec, tags|
-      name = spec[:name] || spec['name']
-      category = spec[:category] || spec['category']
-      next if name.blank? || category.blank?
-
-      tag = Tag.find_or_create_by_tag_name!(name, category:)
-      tag.update!(category:) if tag.category.to_sym != category.to_sym
-      tags[name] ||= tag
-    end.values
-  end
-
-  def materialise_sections sections_by_name, snapshot_tags, post_tags
-    tags_by_name = post_tags.index_by(&:name)
-    snapshot_tags.each do |tag|
-      tags_by_name[tag.name] ||= tag
-    end
-
-    sections_by_name.each_with_object({ }) do |(tag_name, ranges), sections|
-      tag = tags_by_name[tag_name.to_s]
-      next if tag.nil?
-
-      sections[tag.id] = Array(ranges).map { |range| [range[0], range[1]] }
-    end
-  end
-
-  def sync_post_tags! post, desired_tags, sections
-    desired_ids = desired_tags.map(&:id).to_set
-    current_ids = post.tags.pluck(:id).to_set
-    Tag.where(id: desired_ids - current_ids).find_each do |tag|
-      PostTag.create_or_find_by!(post:, tag:, created_user: @actor)
-    end
-    PostTagSection.where(post_id: post.id).destroy_all
-    sections.each do |tag_id, ranges|
-      ranges.each do |begin_ms, end_ms|
-        PostTagSection.create!(post_id: post.id,
-                               tag_id:,
-                               begin_ms:,
-                               end_ms:)
-      end
-    end
-    PostTag.where(post_id: post.id,
-                  tag_id: (current_ids - desired_ids).to_a).kept.find_each do |post_tag|
-      post_tag.discard_by!(@actor)
-    end
-  end
-
-  def sync_parent_posts! post, ids
-    if ids.include?(post.id)
-      post.errors.add :parent_post_ids, '自分自身を親投稿にはできません．'
-      raise ActiveRecord::RecordInvalid, post
-    end
-    missing = ids - Post.where(id: ids).pluck(:id)
-    if missing.present?
-      post.errors.add :parent_post_ids, "存在しない親投稿 Id. があります: #{ missing.join(' ') }"
-      raise ActiveRecord::RecordInvalid, post
-    end
-    ids.each { |parent_post_id| PostImplication.create_or_find_by!(post:, parent_post_id:) }
-  end
-end

backend/app/services/post_import_previewer.rb

@@ -1,522 +0,0 @@
-require 'time'
-require 'timeout'
-
-class PostImportPreviewer
-  FIELDS = [
-      'title',
-      'thumbnail_base',
-      'original_created_from',
-      'original_created_before',
-      'video_ms',
-      'duration',
-      'tags',
-      'parent_post_ids'].freeze
-  FETCH_WARNING_FIELDS = ['url', 'title', 'thumbnail_base'].freeze
-  TITLE_FETCH_WARNING = 'タイトルを取得できませんでした．'.freeze
-  THUMBNAIL_FETCH_WARNING = 'サムネールを取得できませんでした．'.freeze
-  METADATA_FETCH_WARNING = '自動取得に失敗しました．'.freeze
-
-  def preview_rows rows:, fetch_metadata: true, metadata_cache: { }
-    prepared_rows = rows.map { prepare_row(_1) }
-    url_counts = prepared_rows.filter_map { _1[:normal_url] }.tally
-    existing_posts =
-        Post.where(url: prepared_rows.map { _1[:normal_url] }.compact.uniq).index_by(&:url)
-    existing_parent_ids = preload_parent_ids(prepared_rows)
-    preload_metadata!(
-        prepared_rows,
-        fetch_metadata,
-        metadata_cache,
-        existing_posts,
-        url_counts)
-    known_tags =
-        preload_known_tags(
-            prepared_rows,
-            fetch_metadata,
-            metadata_cache,
-            existing_posts,
-            url_counts)
-    prepared_rows.map { |row|
-      preview_row(row,
-                  fetch_metadata:,
-                  metadata_cache:,
-                  existing_posts:,
-                  url_counts:,
-                  known_tags:,
-                  existing_parent_ids:)
-    }
-  end
-
-  def normalised_url value
-    PostUrlNormaliser.normalise(value)
-  end
-
-  private
-
-  def prepare_row row
-    source = row.symbolize_keys
-    url = source[:url].to_s.strip
-    normal_url = normalised_url(url)
-    source.merge(url_text: url, normal_url:, url_error: validate_url_safety(normal_url))
-  end
-
-  def preview_row row,
-                  fetch_metadata:,
-                  metadata_cache:,
-                  existing_posts:,
-                  url_counts:,
-                  known_tags:,
-                  existing_parent_ids:
-    attributes = initial_attributes(row)
-    provenance = initial_provenance(row)
-    tag_sources = initial_tag_sources(row, attributes, provenance)
-    field_warnings = initial_field_warnings(row)
-    base_warnings = initial_base_warnings(row)
-    url = row[:url_text]
-    provenance['url'] = 'manual'
-    normal_url = row[:normal_url]
-    url_for_metadata = normal_url || url
-    existing_post = normal_url.present? ? existing_posts[normal_url] : nil
-
-    validation_errors = {}
-    validation_errors[:url] = ['URL が不正です．'] if normal_url.blank?
-    if row[:url_error].present?
-      validation_errors[:url] = [row[:url_error]]
-    end
-    if normal_url.present? && url_counts[normal_url].to_i > 1
-      validation_errors[:url] = ['URL が重複しています．']
-    end
-
-    if row[:metadata_url].present? && row[:metadata_url] != url_for_metadata
-      clear_automatic_values!(attributes, provenance, tag_sources)
-      field_warnings = { }
-      base_warnings = [ ]
-    end
-
-    if validation_errors.blank? && normal_url.present? && existing_post
-      attributes['tags'] = merged_tags(tag_sources, provenance['tags'])
-      warnings_present = field_warnings.values.any?(&:present?) || base_warnings.present?
-      return { source_row: row[:source_row],
-               url: normal_url,
-               attributes:,
-               provenance:,
-               tag_sources:,
-               metadata_url: url_for_metadata,
-               skip_reason: 'existing',
-               existing_post_id: existing_post.id,
-               field_warnings:,
-               base_warnings:,
-               validation_errors:,
-               status: warnings_present ? 'warning' : 'ready' }
-    end
-
-    should_fetch = validation_errors.blank?
-    should_fetch &&= should_fetch_metadata?(fetch_metadata, row[:source_row].to_i)
-    if should_fetch
-      clear_fetch_warnings!(field_warnings)
-      metadata = metadata_for(url_for_metadata, metadata_cache)
-      if metadata[:validation_errors].present?
-        validation_errors.merge!(metadata[:validation_errors])
-      else
-        apply_metadata!(attributes, provenance, tag_sources, metadata[:data])
-        apply_fetch_warnings!(field_warnings, metadata[:warnings])
-      end
-    end
-
-    attributes['url'] = url
-    validate_basic_data(attributes, validation_errors)
-    validate_preview_tags(merged_tags(tag_sources, provenance['tags']),
-                          validation_errors,
-                          known_tags)
-    validate_parents(attributes['parent_post_ids'], validation_errors, existing_parent_ids)
-    attributes.delete('url')
-    attributes['tags'] = merged_tags(tag_sources, provenance['tags'])
-
-    warnings_present = field_warnings.values.any?(&:present?) || base_warnings.present?
-    { source_row: row[:source_row],
-      url: validation_errors[:url].present? ? url : (normal_url || url),
-      attributes:,
-      provenance:,
-      tag_sources:,
-      metadata_url: url_for_metadata,
-      skip_reason: nil,
-      existing_post_id: nil,
-      field_warnings:,
-      base_warnings:,
-      validation_errors:,
-      status: validation_errors.present? ? 'error' : (warnings_present ? 'warning' : 'ready') }
-  end
-
-  def should_fetch_metadata? fetch_metadata, source_row
-    case fetch_metadata
-    when true then true
-    when Integer then fetch_metadata == source_row
-    when false, nil then false
-    else raise ArgumentError, '取得対象が不正です．'
-    end
-  end
-
-  def initial_attributes row
-    attributes = row[:attributes]&.stringify_keys || { }
-    FIELDS.to_h { |field|
-      value = attributes[field]
-      normalised =
-          if field == 'duration'
-            normalise_duration_attribute(value)
-          elsif field == 'video_ms'
-            value.nil? ? '' : value.to_s
-          else
-            value.to_s
-          end
-      [field, normalised] }
-  end
-
-  def initial_provenance row
-    provenance = row[:provenance]&.stringify_keys || { }
-    FIELDS.to_h { |field| [field, provenance[field].presence || 'automatic'] }
-      .merge('url' => 'manual')
-  end
-
-  def initial_tag_sources row, attributes, provenance
-    sources = row[:tag_sources]&.stringify_keys || { 'automatic' => '', 'manual' => '' }
-    sources['automatic'] = sources['automatic'].to_s
-    sources['manual'] =
-      provenance['tags'] == 'manual' ? attributes['tags'].to_s : sources['manual'].to_s
-    sources
-  end
-
-  def initial_field_warnings row
-    (row[:field_warnings] || { })
-      .stringify_keys
-      .transform_values { |value| Array(value).map(&:to_s) }
-  end
-
-  def initial_base_warnings row
-    Array(row[:base_warnings]).map(&:to_s)
-  end
-
-  def clear_automatic_values! attributes, provenance, tag_sources
-    ['title', 'thumbnail_base', 'original_created_from',
-     'original_created_before', 'video_ms', 'duration'].each do |field|
-      attributes[field] = '' if provenance[field] == 'automatic'
-    end
-    tag_sources['automatic'] = ''
-    attributes['tags'] = merged_tags(tag_sources, provenance['tags'])
-  end
-
-  def clear_fetch_warnings! field_warnings
-    FETCH_WARNING_FIELDS.each do |field|
-      field_warnings.delete(field)
-    end
-  end
-
-  def metadata_for url, cache
-    cache[url] ||= fetch_metadata(url)
-  end
-
-  def fetch_metadata url
-    return { data: { }, warnings: { 'url' => ['URL が空です．'] },
-             validation_errors: { } } if url.blank?
-
-    data = sanitise_metadata(PostMetadataFetcher.fetch(url).stringify_keys.compact)
-    warnings = { }
-    add_field_warning!(warnings, 'title', TITLE_FETCH_WARNING) if data['title'].blank?
-    if data['thumbnail_base'].blank?
-      add_field_warning!(warnings, 'thumbnail_base', THUMBNAIL_FETCH_WARNING)
-    end
-    { data:, warnings:, validation_errors: { } }
-  rescue Preview::UrlSafety::UnsafeUrl => e
-    Rails.logger.info(
-        "post_import_metadata_fetch_unsafe_url "\
-        "#{ { error: e.class.name, message: e.message }.to_json }")
-    { data: { }, warnings: { }, validation_errors: { url: [e.message] } }
-  rescue Preview::HttpFetcher::FetchFailed,
-         Preview::HttpFetcher::ResponseTooLarge => e
-    Rails.logger.info(
-        "post_import_metadata_fetch_failure "\
-        "#{ { error: e.class.name, message: e.message }.to_json }")
-    { data: { }, warnings: { 'url' => [METADATA_FETCH_WARNING] }, validation_errors: { } }
-  end
-
-  def sanitise_metadata metadata
-    {
-        'title' => sanitise_metadata_title(metadata['title']),
-        'thumbnail_base' => sanitise_metadata_url(metadata['thumbnail_base']),
-        'original_created_from' => sanitise_metadata_time(metadata['original_created_from']),
-        'original_created_before' => sanitise_metadata_time(metadata['original_created_before']),
-        'duration' => sanitise_metadata_duration(metadata['duration']),
-        'tags' => metadata['tags'].to_s.presence }.compact
-  end
-
-  def sanitise_metadata_title value
-    value.is_a?(String) ? value.presence : nil
-  end
-
-  def sanitise_metadata_url value
-    return nil unless value.is_a?(String)
-
-    stripped = value.strip
-    return nil if stripped.blank?
-
-    uri = URI.parse(stripped)
-    return nil unless uri.is_a?(URI::HTTP) && uri.host.present?
-
-    stripped
-  rescue URI::InvalidURIError
-    nil
-  end
-
-  def sanitise_metadata_time value
-    return nil unless value.is_a?(String)
-
-    Time.iso8601(value).in_time_zone.change(sec: 0, nsec: 0).iso8601
-  rescue ArgumentError, TypeError
-    nil
-  end
-
-  def sanitise_metadata_duration value
-    return nil unless value.is_a?(String)
-
-    value.presence
-  end
-
-  def normalise_duration_attribute value
-    return '' if value.nil?
-    return value if value.is_a?(String)
-
-    milliseconds = Integer(value, exception: false)
-    return value.to_s if milliseconds.nil? || milliseconds <= 0
-
-    seconds_string = (milliseconds / 1_000.0).to_s
-    seconds_string.end_with?('.0') ? seconds_string.delete_suffix('.0') : seconds_string
-  end
-
-  def preload_metadata! prepared_rows, fetch_metadata, metadata_cache, existing_posts, url_counts
-    urls = prepared_rows.filter_map { |row|
-      next unless row[:normal_url].present?
-      next if row[:url_error].present?
-      next unless should_fetch_metadata?(fetch_metadata, row[:source_row].to_i)
-      next if url_counts[row[:normal_url]].to_i > 1
-      next if existing_posts.key?(row[:normal_url])
-
-      row[:normal_url]
-    }.uniq
-    urls = urls.reject { metadata_cache.key?(_1) }
-    return if urls.empty?
-
-    url_queue = Queue.new
-    result_queue = Queue.new
-    urls.each { url_queue << _1 }
-    workers = [urls.length, 4].min.times.map {
-      Thread.new {
-        Rails.application.executor.wrap do
-          loop do
-            url = url_queue.pop(true)
-            result_queue << [url, safe_fetch_metadata(url)]
-          rescue ThreadError
-            break
-          end
-        end
-      }
-    }
-    Timeout.timeout(15) { workers.each(&:join) }
-  rescue Timeout::Error
-    workers&.each(&:kill)
-  ensure
-    workers&.each(&:join)
-    while result_queue&.size.to_i.positive?
-      url, result = result_queue.pop
-      metadata_cache[url] = result
-    end
-    urls&.each do |url|
-      metadata_cache[url] ||= { data: { }, warnings: { 'url' => [METADATA_FETCH_WARNING] } }
-    end
-  end
-
-  def safe_fetch_metadata url
-    fetch_metadata(url)
-  rescue Preview::UrlSafety::UnsafeUrl => e
-    Rails.logger.info(
-        "post_import_metadata_fetch_unsafe_url "\
-        "#{ { error: e.class.name, message: e.message }.to_json }")
-    { data: { }, warnings: { }, validation_errors: { url: [e.message] } }
-  rescue StandardError => e
-    Rails.logger.error(
-        "post_import_metadata_fetch_unexpected_failure "\
-        "#{ { error: e.class.name, message: e.message }.to_json }")
-    { data: { }, warnings: { 'url' => [METADATA_FETCH_WARNING] }, validation_errors: { } }
-  end
-
-  def preload_known_tags prepared_rows, fetch_metadata, metadata_cache, existing_posts, url_counts
-    names = prepared_rows.flat_map { |row|
-      attributes = initial_attributes(row)
-      provenance = initial_provenance(row)
-      tag_sources = initial_tag_sources(row, attributes, provenance)
-      if metadata_url_changed?(row)
-        clear_automatic_values!(attributes, provenance, tag_sources)
-      end
-      if should_apply_metadata_to_row?(row, fetch_metadata, existing_posts, url_counts)
-        metadata = metadata_for(row[:normal_url], metadata_cache)
-        apply_metadata!(attributes, provenance, tag_sources, metadata[:data])
-      end
-      preview_tag_names(merged_tags(tag_sources, provenance['tags']))
-    }.compact.uniq
-    return { } if names.empty?
-
-    Tag.joins(:tag_name)
-      .where(tag_names: { name: names })
-      .includes(:tag_name)
-      .to_a
-      .index_by(&:name)
-  end
-
-  def preload_parent_ids prepared_rows
-    ids = prepared_rows.flat_map { |row|
-      attributes = initial_attributes(row)
-      preview_parent_ids(attributes['parent_post_ids'])
-    }.uniq
-    return { } if ids.empty?
-
-    Post.where(id: ids).pluck(:id).to_h { [_1, true] }
-  end
-
-  def metadata_url_changed? row
-    row[:metadata_url].present? && row[:metadata_url] != (row[:normal_url] || row[:url_text])
-  end
-
-  def should_apply_metadata_to_row? row, fetch_metadata, existing_posts, url_counts
-    normal_url = row[:normal_url]
-    return false if normal_url.blank?
-    return false if row[:url_error].present?
-    return false if url_counts[normal_url].to_i > 1
-    return false if existing_posts.key?(normal_url)
-
-    should_fetch_metadata?(fetch_metadata, row[:source_row].to_i)
-  end
-
-  def validate_url_safety normal_url
-    return nil if normal_url.blank?
-
-    Preview::UrlSafety.validate(normal_url)
-    nil
-  rescue Preview::UrlSafety::UnsafeUrl => e
-    e.message
-  end
-
-  def apply_metadata! attributes, provenance, tag_sources, metadata
-    metadata.each do |field, value|
-      if field == 'tags'
-        next if provenance['tags'] == 'manual'
-
-        tag_sources['automatic'] = value.to_s
-        attributes['tags'] = merged_tags(tag_sources)
-        next
-      end
-      next unless provenance[field] == 'automatic'
-
-      attributes[field] = value
-      provenance[field] = 'automatic'
-    end
-  end
-
-  def apply_fetch_warnings! field_warnings, warnings
-    warnings.each do |field, values|
-      values.each do |value|
-        add_field_warning!(field_warnings, field, value)
-      end
-    end
-  end
-
-  def add_field_warning! field_warnings, field, message
-    field_warnings[field] ||= []
-    field_warnings[field] << message unless field_warnings[field].include?(message)
-  end
-
-  def merged_tags sources, origin = nil
-    return sources['manual'].to_s if origin == 'manual'
-
-    sources['automatic'].to_s
-  end
-
-  def preview_tag_names raw
-    names = raw.to_s.split
-    return [] if names.empty?
-    if names.any? { _1.downcase.start_with?('nico:') }
-      return []
-    end
-
-    names.map { |name| TagName.canonicalise(name.sub(/\[.*\]\z/, '')).first }
-  rescue Tag::SectionLiteralParseError
-    []
-  end
-
-  def validate_preview_tags raw, errors, known_tags
-    names = raw.to_s.split
-    return if names.empty?
-    if names.any? { _1.downcase.start_with?('nico:') }
-      errors[:tags] = ['ニコニコ・タグは直接指定できません．']
-      return
-    end
-
-    parsed = names.map { |name| TagName.canonicalise(name.sub(/\[.*\]\z/, '')).first }
-    existing = parsed.filter_map { known_tags[_1] }
-    deprecated = existing.select(&:deprecated?).map(&:name)
-    errors[:tags] = ["廃止済みタグがあります: #{ deprecated.join(' ') }"] if deprecated.present?
-  rescue Tag::SectionLiteralParseError
-    errors[:tags] = ['タグ区間の記法が不正です．']
-  end
-
-  def validate_basic_data attributes, errors
-    post = Post.new(title: attributes['title'].presence,
-                    url: attributes['url'],
-                    thumbnail_base: attributes['thumbnail_base'].presence,
-                    original_created_from: attributes['original_created_from'].presence,
-                    original_created_before: attributes['original_created_before'].presence,
-                    video_ms: parse_video_ms(attributes, errors))
-    post.valid?
-    post.errors.each do |error|
-      next if error.attribute == :url && error.type == :taken
-
-      (errors[error.attribute] ||= []) << error.message
-    end
-  end
-
-  def parse_video_ms attributes, errors
-    return nil unless attributes['tags'].to_s.split.include?('動画')
-
-    video_ms = attributes['video_ms']
-    if video_ms.present?
-      value = Integer(video_ms, exception: false)
-      if value&.positive?
-        return value
-      end
-
-      errors[:video_ms] = ['動画時間の記法が不正です．']
-      return nil
-    end
-
-    value = attributes['duration']
-    return nil if value.blank?
-
-    Tag.time_to_ms!(value.to_s, tag_name: '動画時間')
-  rescue Tag::SectionLiteralParseError
-    errors[:video_ms] = ['動画時間の記法が不正です．']
-    nil
-  end
-
-  def preview_parent_ids raw
-    raw.to_s.split.map { Integer(_1, exception: false) }.compact
-  end
-
-  def validate_parents raw, errors, existing_parent_ids
-    ids = raw.to_s.split.map { Integer(_1, exception: false) }
-    return if ids.compact.empty? && raw.to_s.blank?
-
-    if ids.any? { _1.nil? || _1 <= 0 }
-      errors[:parent_post_ids] = ['親投稿 Id. が不正です．']
-      return
-    end
-    if ids.uniq.any? { !existing_parent_ids[_1] }
-      errors[:parent_post_ids] = ['存在しない親投稿 Id. があります．']
-    end
-  end
-end

backend/app/services/post_metadata_fetcher.rb

@@ -1,199 +0,0 @@
-require 'time'
-require 'date'
-
-class PostMetadataFetcher
-  TIMESTAMP_PATTERN =
-      Regexp.new(
-          '\A(\d{4})-(\d{2})-(\d{2})T(\d{2})' \
-          '(?::(\d{2})(?::(\d{2})(?:\.(\d+))?)?)?' \
-          '(Z|[+-]\d{2}:?\d{2})?\z')
-
-  def self.fetch raw_url
-    uri, = Preview::UrlSafety.validate(raw_url)
-    response = Preview::HttpFetcher.fetch(
-        uri.to_s,
-        max_bytes: Preview::ThumbnailFetcher::HTML_MAX_BYTES)
-    metadata = Preview::HtmlMetadataExtractor.extract(response)
-    document = Nokogiri::HTML.parse(response.body)
-    content = lambda { |name|
-      document
-        .at_css("meta[property='#{ name }'], meta[name='#{ name }']")
-        &.[]('content')
-        &.strip
-        &.presence
-    }
-    duration = content.call('og:video:duration') || content.call('video:duration')
-    published = content.call('article:published_time') || content.call('date')
-    created_range = original_created_range(published)
-    platform_tags = platform_tags(uri)
-    { title: metadata[:title],
-      thumbnail_base:
-          Preview::KnownSiteExtractor.thumbnail_url(uri) || metadata[:image_url],
-      original_created_from: serialise_time(created_range&.first),
-      original_created_before: serialise_time(created_range&.last),
-      duration: serialise_duration(duration),
-      display_tags: display_tags(platform_tags),
-      tags: platform_tags.join(' ') }
-  end
-
-  def self.platform_tags uri
-    return ['動画', 'YouTube'] if Preview::KnownSiteExtractor.youtube_video_id(uri)
-    return ['動画', 'ニコニコ'] if Preview::KnownSiteExtractor.niconico_video_id(uri)
-
-    []
-  end
-
-  def self.display_tags names
-    return [] if names.blank?
-
-    existing_tags =
-        Tag
-        .joins(:tag_name)
-        .where(tag_names: { name: names })
-        .index_by(&:name)
-
-    names.map { |name|
-      tag = existing_tags[name]
-      {
-          name: name,
-          category: (tag&.category || 'meta'),
-          section_literals: [] }
-    }
-  end
-
-  def self.original_created_range value
-    return nil if value.blank?
-
-    raw = value.to_s.strip
-    from, before =
-        case raw
-        when /\A(\d{4})\z/
-          year = Regexp.last_match(1).to_i
-          from = Time.zone.local(year, 1, 1)
-          [from, from + 1.year]
-        when /\A(\d{4})-(\d{2})\z/
-          year = Regexp.last_match(1).to_i
-          month = Regexp.last_match(2).to_i
-          return nil unless month.between?(1, 12)
-
-          from = Time.zone.local(year, month, 1)
-          [from, from + 1.month]
-        when /\A(\d{4})-(\d{2})-(\d{2})\z/
-          year = Regexp.last_match(1).to_i
-          month = Regexp.last_match(2).to_i
-          day = Regexp.last_match(3).to_i
-          return nil unless Date.valid_date?(year, month, day)
-
-          from = Time.zone.local(year, month, day)
-          [from, from + 1.day]
-        else
-          parse_timestamp_range(raw)
-        end
-    return nil if from.nil? || before.nil?
-
-    [from, before]
-  rescue ArgumentError, TypeError
-    nil
-  end
-
-  def self.parse_timestamp_range raw
-    match = raw.match(TIMESTAMP_PATTERN)
-    return nil unless match
-
-    year = match[1].to_i
-    month = match[2].to_i
-    day = match[3].to_i
-    hour = match[4].to_i
-    minute = match[5]&.to_i || 0
-    second = match[6]&.to_i || 0
-    fraction = match[7]
-    offset = match[8]
-    return nil unless valid_timestamp_components?(year, month, day, hour, minute, second)
-    return nil unless valid_offset?(offset)
-
-    nanoseconds = parse_nanoseconds(fraction)
-    timestamp =
-        if offset.present?
-          Time.new(
-              year,
-              month,
-              day,
-              hour,
-              minute,
-              second + Rational(nanoseconds, 1_000_000_000),
-              parse_offset(offset)).in_time_zone
-        else
-          Time.zone.local(year, month, day, hour, minute, second).change(nsec: nanoseconds)
-        end
-
-    from = timestamp.change(sec: 0, nsec: 0)
-    before =
-        if match[5].nil?
-          from + 1.hour
-        else
-          from + 1.minute
-        end
-    [from, before]
-  end
-
-  def self.parse_nanoseconds value
-    return 0 if value.blank?
-
-    digits = value[0, 9].ljust(9, '0')
-    Integer(digits, 10)
-  end
-
-  def self.parse_offset value
-    return '+00:00' if value == 'Z'
-
-    value.match?(/\A[+-]\d{2}:\d{2}\z/) ? value : "#{ value[0, 3] }:#{ value[3, 2] }"
-  end
-
-  def self.serialise_duration value
-    seconds = Float(value)
-    return nil unless seconds.positive?
-
-    milliseconds = (seconds * 1_000).round
-    seconds_string = (milliseconds / 1_000.0).to_s
-    seconds_string.end_with?('.0') ? seconds_string.delete_suffix('.0') : seconds_string
-  rescue ArgumentError, TypeError
-    nil
-  end
-
-  def self.valid_timestamp_components? year, month, day, hour, minute, second
-    return false unless Date.valid_date?(year, month, day)
-    return false unless hour.between?(0, 23)
-    return false unless minute.between?(0, 59)
-    return false unless second.between?(0, 59)
-
-    true
-  end
-
-  def self.valid_offset? value
-    return true if value.nil? || value == 'Z'
-
-    match = value.match(/\A([+-])(\d{2}):?(\d{2})\z/)
-    return false if match.nil?
-
-    hours = match[2].to_i
-    minutes = match[3].to_i
-    hours.between?(0, 23) && minutes.between?(0, 59)
-  end
-
-  def self.serialise_time value
-    return nil if value.nil?
-
-    value.nsec.zero? ? value.iso8601 : value.iso8601(9)
-  end
-
-  private_class_method :platform_tags,
-                       :display_tags,
-                       :original_created_range,
-                       :parse_timestamp_range,
-                       :parse_nanoseconds,
-                       :parse_offset,
-                       :serialise_duration,
-                       :valid_timestamp_components?,
-                       :valid_offset?,
-                       :serialise_time
-end

backend/app/services/post_thumbnail_attachment_builder.rb

@@ -1,11 +0,0 @@
-class PostThumbnailAttachmentBuilder
-  def self.build thumbnail:, thumbnail_base:
-    if thumbnail_base.present?
-      return Post.remote_thumbnail_attachment(thumbnail_base)
-    end
-
-    return nil if thumbnail.blank?
-
-    Post.resized_thumbnail_attachment(thumbnail)
-  end
-end

backend/app/services/post_thumbnail_upload_validator.rb

@@ -1,34 +0,0 @@
-class PostThumbnailUploadValidator
-  MAX_THUMBNAIL_BYTES = 20 * 1024 * 1024
-  ALLOWED_CONTENT_TYPES = Preview::ThumbnailFetcher::RASTER_IMAGE_CONTENT_TYPES.freeze
-
-  class InvalidUpload < StandardError; end
-
-  def self.validate! thumbnail
-    return if thumbnail.blank?
-    unless thumbnail.is_a?(ActionDispatch::Http::UploadedFile)
-      raise InvalidUpload, 'thumbnail upload が不正です．'
-    end
-    raise InvalidUpload, 'thumbnail file size が大きすぎます．' if thumbnail.size > MAX_THUMBNAIL_BYTES
-    raise InvalidUpload, 'サムネイル画像の形式が不正です．' unless allowed_content_type?(thumbnail.content_type)
-    bytes = thumbnail.read
-    raise InvalidUpload, 'サムネイル画像の形式が不正です．' if Post.svg_document_bytes?(bytes)
-    unless Post.raster_thumbnail_bytes?(bytes)
-      raise InvalidUpload, 'サムネイル画像の形式が不正です．'
-    end
-
-    attachment = Post.resized_thumbnail_attachment(
-        StringIO.new(bytes),
-        content_type: thumbnail.content_type)
-    attachment[:io].close if attachment[:io].respond_to?(:close)
-  rescue MiniMagick::Error, Timeout::Error
-    raise InvalidUpload, 'サムネイル画像の変換に失敗しました．'
-  ensure
-    thumbnail&.rewind if thumbnail.respond_to?(:rewind)
-  end
-
-  def self.allowed_content_type? content_type
-    mime_type = content_type.to_s.split(';', 2).first.to_s.downcase.strip
-    ALLOWED_CONTENT_TYPES.include?(mime_type)
-  end
-end

backend/app/services/post_url_normaliser.rb

@@ -1,13 +0,0 @@
-class PostUrlNormaliser
-  def self.normalise raw_url
-    value = raw_url.to_s.strip
-    uri = URI.parse(value)
-    return nil unless uri.is_a?(URI::HTTP) && uri.host.present?
-
-    uri.host = uri.host.downcase
-    uri.path = uri.path.sub(/\/\z/, '') if uri.path.present?
-    PostUrlSanitisationRule.sanitise(uri.to_s)
-  rescue URI::InvalidURIError
-    nil
-  end
-end

backend/app/services/post_version_recorder.rb

@@ -23,7 +23,6 @@ class PostVersionRecorder < VersionRecorder
     { title: @record.title,
       url: @record.url,
       thumbnail_base: @record.thumbnail_base,
-      video_ms: @record.video_ms,
       tags: @record.snapshot_tag_names.join(' '),
       parent_post_ids: @record.snapshot_parent_post_ids.join(' '),
       original_created_from: @record.original_created_from,

backend/app/services/preview/html_metadata_extractor.rb

@@ -1,21 +0,0 @@
-module Preview
-  class HtmlMetadataExtractor
-    IMAGE_SELECTORS = [
-      'meta[property="og:image"]',
-      'meta[name="twitter:image"]',
-      'meta[name="thumbnail"]'
-    ].freeze
-
-    def self.extract(response)
-      document = Nokogiri::HTML.parse(response.body)
-      image_url = IMAGE_SELECTORS.filter_map {
-        document.at_css(_1)&.[]('content')&.strip.presence
-      }.first
-
-      { title: document.at_css('title')&.text&.strip,
-        image_url: image_url ? URI.join(response.url, image_url).to_s : nil }
-    rescue URI::InvalidURIError
-      { title: document.at_css('title')&.text&.strip, image_url: nil }
-    end
-  end
-end

backend/app/services/preview/http_fetcher.rb

@@ -1,123 +0,0 @@
-require 'net/http'
-require 'json'
-
-module Preview
-  class HttpFetcher
-    class FetchFailed < StandardError; end
-    class FetchTimeout < FetchFailed; end
-    class ResponseTooLarge < FetchFailed; end
-
-    MAX_REDIRECTS = 5
-    DEFAULT_MAX_BYTES = 5.megabytes
-
-    Response = Data.define(:body, :content_type, :url)
-
-    def self.fetch(raw_url, max_bytes: DEFAULT_MAX_BYTES, redirects: MAX_REDIRECTS)
-      uri, addresses = UrlSafety.validate(raw_url)
-      response = request(uri, addresses.first, max_bytes)
-
-      if response.is_a?(Net::HTTPRedirection)
-        location = response['location']
-        if redirects.zero?
-          log_failure(:redirect_limit,
-                      url: uri.to_s,
-                      redirects:,
-                      location:,
-                      content_type: response['content-type'],
-                      content_length: response['content-length'])
-          raise FetchFailed, 'redirect が多すぎます．'
-        end
-
-        if location.blank?
-          log_failure(:blank_redirect_location,
-                      url: uri.to_s,
-                      redirects:,
-                      content_type: response['content-type'],
-                      content_length: response['content-length'])
-          raise FetchFailed, 'redirect 先が不正です．'
-        end
-
-        redirect_url =
-            begin
-              URI.join(uri, location).to_s
-            rescue URI::InvalidURIError => e
-              log_failure(:invalid_redirect_location,
-                          url: uri.to_s,
-                          redirects:,
-                          location:,
-                          error: e.class.name,
-                          message: e.message)
-              raise FetchFailed, 'redirect 先が不正です．'
-            end
-
-        return fetch(redirect_url, max_bytes:, redirects: redirects - 1)
-      end
-
-      unless response.is_a?(Net::HTTPSuccess)
-        log_failure(:http_status,
-                    url: uri.to_s,
-                    code: response.code,
-                    content_type: response['content-type'],
-                    content_length: response['content-length'])
-        raise FetchFailed, "外部サーバーが HTTP #{ response.code } を返しました．"
-      end
-
-      Response.new(response.body, response['content-type'].to_s, uri.to_s)
-    rescue Net::OpenTimeout, Net::ReadTimeout, Timeout::Error => e
-      log_failure(:timeout, url: uri&.to_s || raw_url, error: e.class.name, message: e.message)
-      raise FetchTimeout, e.message
-    rescue SocketError, SystemCallError, OpenSSL::SSL::SSLError, EOFError => e
-      log_failure(:network_error, url: uri&.to_s || raw_url, error: e.class.name,
-                  message: e.message)
-      raise FetchFailed, e.message
-    end
-
-    def self.request(uri, ip_address, max_bytes)
-      http = Net::HTTP.new(uri.host, uri.port)
-      http.ipaddr = ip_address
-      http.use_ssl = uri.scheme == 'https'
-      http.open_timeout = 5
-      http.read_timeout = 8
-      http.write_timeout = 5
-
-      request = Net::HTTP::Get.new(uri)
-      request['User-Agent'] = 'BTRC-Hub thumbnail preview'
-      request['Accept'] = 'text/html,image/*;q=0.9,*/*;q=0.1'
-
-      http.request(request) do |response|
-        length = response['content-length'].to_i
-        if length > max_bytes
-          log_failure(:response_too_large,
-                      url: uri.to_s,
-                      content_type: response['content-type'],
-                      content_length: response['content-length'],
-                      max_bytes:)
-          raise ResponseTooLarge, '外部データが大きすぎます．'
-        end
-
-        body = +''
-        response.read_body do |chunk|
-          body << chunk
-          next unless body.bytesize > max_bytes
-
-          log_failure(:response_too_large,
-                      url: uri.to_s,
-                      content_type: response['content-type'],
-                      content_length: response['content-length'],
-                      bytes_read: body.bytesize,
-                      max_bytes:)
-          raise ResponseTooLarge, '外部データが大きすぎます．'
-        end
-        response.instance_variable_set(:@body, body)
-        response.instance_variable_set(:@read, true)
-        return response
-      end
-    end
-
-    def self.log_failure(reason, **payload)
-      Rails.logger.warn("preview_http_fetcher_failure #{ { reason:, **payload }.to_json }")
-    end
-
-    private_class_method :request, :log_failure
-  end
-end

backend/app/services/preview/known_site_extractor.rb

@@ -1,34 +0,0 @@
-module Preview
-  class KnownSiteExtractor
-    def self.thumbnail_url(uri)
-      youtube_thumbnail(uri)
-    end
-
-    def self.youtube_video_id(uri)
-      case uri.host&.downcase
-      when 'youtu.be'
-        uri.path.split('/').reject(&:blank?).first
-      when 'www.youtube.com', 'youtube.com', 'm.youtube.com'
-        uri.path == '/watch' ? URI.decode_www_form(uri.query.to_s).to_h['v'] : nil
-      end&.then { _1 if _1.match?(/\A[A-Za-z0-9_-]{6,20}\z/) }
-    end
-
-    def self.niconico_video_id(uri)
-      case uri.host&.downcase
-      when 'www.nicovideo.jp', 'nicovideo.jp'
-        uri.path[%r{\A/watch/(sm\d+)\z}, 1]
-      when 'nico.ms'
-        uri.path[%r{\A/(sm\d+)\z}, 1]
-      end
-    end
-
-    def self.youtube_thumbnail(uri)
-      id = youtube_video_id(uri)
-      return unless id
-
-      "https://i.ytimg.com/vi/#{ id }/hqdefault.jpg"
-    end
-
-    private_class_method :youtube_thumbnail
-  end
-end

backend/app/services/preview/thumbnail_fetcher.rb

@@ -1,102 +0,0 @@
-module Preview
-  class ThumbnailFetcher
-    class GenerationFailed < StandardError; end
-    RASTER_IMAGE_CONTENT_TYPES = [
-      'image/jpeg', 'image/png', 'image/gif', 'image/webp'
-    ].freeze
-    HTML_MAX_BYTES = 1.megabyte
-    NICONICO_XML_MAX_BYTES = 256.kilobytes
-
-    def self.fetch(raw_url)
-      uri, = UrlSafety.validate(raw_url)
-
-      known_url = KnownSiteExtractor.thumbnail_url(uri)
-      image = fetch_image_or_nil(known_url) if known_url
-      return image if image
-
-      niconico_url = niconico_thumbnail_url(uri)
-      image = fetch_image_or_nil(niconico_url) if niconico_url
-      return image if image
-
-      page = HttpFetcher.fetch(uri.to_s, max_bytes: HTML_MAX_BYTES)
-      metadata = HtmlMetadataExtractor.extract(page)
-      raise GenerationFailed, 'サムネール画像が見つかりませんでした．' if metadata[:image_url].blank?
-
-      fetch_image!(metadata[:image_url])
-    end
-
-    def self.fetch_image_response(raw_url)
-      uri, = UrlSafety.validate(raw_url)
-      response = HttpFetcher.fetch(uri.to_s)
-      unless Post.remote_thumbnail_image_bytes?(
-                 response.body,
-                 content_type: response.content_type)
-        raise GenerationFailed, 'サムネール画像が見つかりませんでした．'
-      end
-
-      response
-    rescue HttpFetcher::FetchTimeout
-      raise
-    rescue HttpFetcher::ResponseTooLarge
-      raise
-    rescue HttpFetcher::FetchFailed
-      raise GenerationFailed, 'サムネール画像を取得できませんでした．'
-    end
-
-    def self.title(raw_url)
-      uri, = UrlSafety.validate(raw_url)
-      HtmlMetadataExtractor.extract(
-          HttpFetcher.fetch(uri.to_s, max_bytes: HTML_MAX_BYTES))[:title]
-    end
-
-    def self.fetch_image_or_nil(url)
-      return nil if url.blank?
-
-      response = HttpFetcher.fetch(url)
-      return nil unless Post.remote_thumbnail_image_bytes?(
-                            response.body,
-                            content_type: response.content_type)
-
-      response.body
-    rescue HttpFetcher::FetchTimeout
-      raise
-    rescue HttpFetcher::FetchFailed
-      nil
-    end
-
-    def self.fetch_image!(url)
-      fetch_image_response(url).body
-    end
-
-    def self.niconico_thumbnail_url(uri)
-      video_id = KnownSiteExtractor.niconico_video_id(uri)
-      return nil if video_id.blank?
-
-      response = HttpFetcher.fetch("https://ext.nicovideo.jp/api/getthumbinfo/#{ video_id }",
-                                   max_bytes: NICONICO_XML_MAX_BYTES)
-      xml = Nokogiri::XML(response.body)
-      return nil unless xml.at_xpath('/nicovideo_thumb_response/@status')&.value == 'ok'
-
-      xml.at_xpath('//thumbnail_url')&.text&.strip.presence
-    rescue HttpFetcher::FetchFailed, HttpFetcher::FetchTimeout => e
-      payload = {
-          url: uri.to_s,
-          video_id:,
-          error: e.class.name,
-          message: e.message }
-      Rails.logger.info("preview_niconico_getthumbinfo_fallback #{ payload.to_json }")
-      nil
-    rescue Nokogiri::XML::SyntaxError => e
-      payload = {
-          url: uri.to_s,
-          video_id:,
-          error: e.class.name,
-          message: e.message }
-      Rails.logger.info("preview_niconico_getthumbinfo_fallback #{ payload.to_json }")
-      nil
-    end
-
-    private_class_method :fetch_image_or_nil, :fetch_image!,
-                         :niconico_thumbnail_url
-  end
-end

backend/app/services/preview/url_safety.rb

@@ -1,55 +0,0 @@
-require 'resolv'
-require 'ipaddr'
-require 'uri'
-
-module Preview
-  class UrlSafety
-    class UnsafeUrl < StandardError; end
-
-    FORBIDDEN_NETWORKS = [
-      '0.0.0.0/8', '10.0.0.0/8', '100.64.0.0/10', '127.0.0.0/8',
-      '169.254.0.0/16', '172.16.0.0/12', '192.0.0.0/24',
-      '192.0.2.0/24', '192.168.0.0/16', '198.18.0.0/15',
-      '198.51.100.0/24', '203.0.113.0/24', '224.0.0.0/4',
-      '240.0.0.0/4', '::/128', '::1/128', 'fc00::/7', 'fe80::/10',
-      'ff00::/8', '2001:db8::/32', '::ffff:0:0/96'
-    ].map { IPAddr.new(_1) }.freeze
-
-    def self.validate(raw_url)
-      value = raw_url.to_s.strip
-      if value.match?(/\A[a-z][a-z0-9+\-.]*:/i)
-        unless value.match?(/\Ahttps?:\/\//i)
-          raise UnsafeUrl, 'http または https の URL を指定してください．'
-        end
-      else
-        value = "http://#{ value }"
-      end
-      uri = URI.parse(value)
-
-      unless ['http', 'https'].include?(uri.scheme&.downcase) && uri.host.present?
-        raise UnsafeUrl, 'http または https の URL を指定してください．'
-      end
-      raise UnsafeUrl, 'userinfo つき URL は使用できません．' if uri.userinfo.present?
-
-      addresses = Resolv.getaddresses(uri.host)
-      raise UnsafeUrl, 'URL のホストを解決できません．' if addresses.empty?
-
-      parsed_addresses = addresses.map { IPAddr.new(_1) }
-      if parsed_addresses.any? { |address| forbidden?(address) }
-        raise UnsafeUrl, '安全でない接続先は使用できません．'
-      end
-
-      [uri, parsed_addresses.map(&:to_s)]
-    rescue Resolv::ResolvError
-      raise UnsafeUrl, 'URL のホストを解決できません．'
-    rescue URI::InvalidURIError, IPAddr::InvalidAddressError
-      raise UnsafeUrl, 'URL が不正です．'
-    end
-
-    def self.forbidden?(address)
-      FORBIDDEN_NETWORKS.any? { _1.include?(address) }
-    end
-
-    private_class_method :forbidden?
-  end
-end

backend/app/services/similarity/calc.rb

@@ -1,6 +1,6 @@
 module Similarity
   class Calc
-    def self.call model, tgt, scope: nil
+    def self.call model, tgt
       similarity_model = "#{ model.name }Similarity".constantize
 
       # 最大保存件数
@@ -8,8 +8,7 @@ module Similarity
 
       similarity_model.delete_all
 
-      scope ||= model.all
-      posts = scope.includes(tgt).select(:id).to_a
+      posts = model.includes(tgt).select(:id).to_a
 
       tag_ids = { }
       tag_cnts = { }

backend/app/services/tag_version_recorder.rb

@@ -16,7 +16,6 @@ class TagVersionRecorder < VersionRecorder
   def snapshot_attributes
     { name: @record.name,
       category: @record.category,
-      deprecated_at: @record.deprecated_at,
       aliases: @record.snapshot_aliases.join(' '),
       parent_tag_ids: @record.snapshot_parent_tag_ids.join(' ') }
   end

backend/app/services/theatre_post_advancer.rb

@@ -1,29 +0,0 @@
-class TheatrePostAdvancer
-  def self.call(theatre:)
-    new(theatre:).call
-  end
-
-  def initialize(theatre:)
-    @theatre = theatre
-  end
-
-  def call
-    previous_post = theatre.current_post
-    post = TheatrePostSelector.new(theatre:).select
-
-    TheatreSkipVote.where(theatre:, post: previous_post).delete_all if previous_post
-
-    theatre.update!(current_post: post, current_post_started_at: post ? Time.current : nil)
-
-    if post
-      position = (theatre.programmes.maximum(:position) || 0) + 1
-      theatre.programmes.create!(position:, post:)
-    end
-
-    post
-  end
-
-  private
-
-  attr_reader :theatre
-end

backend/app/services/theatre_post_selector.rb

@@ -1,119 +0,0 @@
-class TheatrePostSelector
-  Candidate = Struct.new(:post, :weight, :penalty, :tags, keyword_init: true)
-  ELIGIBLE_POST_URL_CONDITION =
-      ["url LIKE '%nicovideo.jp%'",
-       "url LIKE '%youtube.com/watch%'",
-       "url LIKE '%youtu.be/%'"]
-      .join(' OR ')
-
-  def initialize theatre:
-    @theatre = theatre
-  end
-
-  def select
-    candidates = weighted_candidates
-    return nil if candidates.empty?
-
-    total = candidates.sum(&:weight)
-    target = rand * total
-
-    candidates.each do |candidate|
-      target -= candidate.weight
-      return candidate.post if target <= 0
-    end
-
-    candidates.last.post
-  end
-
-  def weight_json limit: 20
-    candidates = weighted_candidates
-    sorted = candidates.sort_by { |candidate| [candidate.weight, candidate.post.id] }
-
-    { tag_penalties: tag_penalty_json,
-      lightest_posts: post_weight_json(sorted.first(limit)),
-      heaviest_posts: post_weight_json(sorted.reverse.first(limit)) }
-  end
-
-  private
-
-  attr_reader :theatre
-
-  def weighted_candidates
-    @weighted_candidates ||= begin
-      penalties = tag_penalties
-      posts = eligible_posts.includes(tags: :tag_name).to_a
-
-      posts.map do |post|
-        post_tags = post.tags.to_a
-        penalty = post_tags.sum { |tag| penalties[tag.id].to_i }
-
-        Candidate.new(
-            post:,
-            penalty:,
-            tags: post_tags,
-            weight: 1.0 / (1.0 + penalty))
-      end
-    end
-  end
-
-  def eligible_posts
-    posts = Post.where(ELIGIBLE_POST_URL_CONDITION)
-    posts = posts.where.not(id: theatre.current_post_id) if theatre.current_post_id
-    posts
-  end
-
-  def active_user_ids
-    @active_user_ids ||= theatre.watching_users.ids
-  end
-
-  def tag_penalties
-    @tag_penalties ||=
-      if active_user_ids.empty?
-        {}
-      else
-        TheatreSkipEventVoter
-          .joins(theatre_skip_event: :event_tags)
-          .where(user_id: active_user_ids)
-          .group('theatre_skip_event_tags.tag_id')
-          .count
-      end
-  end
-
-  def tag_penalty_json
-    return [] if tag_penalties.empty?
-
-    tags = Tag.where(id: tag_penalties.keys).includes(:tag_name).index_by(&:id)
-
-    tag_penalties
-      .map { |tag_id, penalty|
-        tag = tags[tag_id]
-        next unless tag
-
-        { tag: light_tag_json(tag),
-          penalty: }
-      }
-      .compact
-      .sort_by { |row| [-row[:penalty], row[:tag][:name].to_s] }
-  end
-
-  def post_weight_json candidates
-    candidates.map { |candidate|
-      { post: light_post_json(candidate.post),
-        weight: candidate.weight,
-        penalty: candidate.penalty,
-        tags: candidate.tags.map { |tag| light_tag_json(tag) } }
-    }
-  end
-
-  def light_post_json post
-    { id: post.id,
-      title: post.title,
-      url: post.url }
-  end
-
-  def light_tag_json tag
-    { id: tag.id,
-      name: tag.name,
-      category: tag.category }
-  end
-end

backend/app/services/theatre_skip_finalizer.rb

@@ -1,40 +0,0 @@
-class TheatreSkipFinalizer
-  def self.call(theatre:, user:)
-    new(theatre:, user:).call
-  end
-
-  def initialize(theatre:, user:)
-    @theatre = theatre
-    @user = user
-  end
-
-  def call
-    return unless theatre.current_post
-
-    post = theatre.current_post
-    voters = TheatreSkipVote.where(theatre:, post:).includes(:user).map(&:user)
-    return if voters.empty?
-
-    event = TheatreSkipEvent.create!(
-        theatre:,
-        post:,
-        skipped_by_user: user,
-        programme_position: theatre.programmes.maximum(:position))
-
-    voters.uniq(&:id).each do |voter|
-      TheatreSkipEventVoter.create!(theatre_skip_event: event, user: voter)
-    end
-
-    post.tags.find_each do |tag|
-      TheatreSkipEventTag.create!(theatre_skip_event: event, tag:)
-    end
-
-    TheatreSkipVote.where(theatre:, post:).delete_all
-
-    event
-  end
-
-  private
-
-  attr_reader :theatre, :user
-end

backend/app/services/version_recorder.rb

@@ -16,20 +16,19 @@ class VersionRecorder
       @record = record_class.unscoped.lock.find(@record.id)
       latest = latest_version
 
-      validate_version_sequence!(latest)
+      if !(latest) && @event_type != 'create'
+        raise "#{ version_class.name } first event must be create"
+      end
+
+      if @event_type == 'create' && latest
+        raise "#{ version_class.name } create event already exists"
+      end
 
       attrs = snapshot_attributes
 
-      if @event_type == 'update' && latest && same_snapshot?(latest, attrs)
-        return latest
-      end
+      return latest if @event_type == 'update' && latest && same_snapshot?(latest, attrs)
 
-      version = version_class.create!(
-          base_attributes(latest).merge(record_key => @record).merge(attrs))
-
-      update_record_version_no!(version.version_no)
-
-      version
+      version_class.create!(base_attributes(latest).merge(record_key => @record).merge(attrs))
     end
   end
 
@@ -46,34 +45,10 @@ class VersionRecorder
       created_by_user: @created_by_user }
   end
 
-  def update_record_version_no! version_no
-    @record.update_columns(version_no:)
-    @record.version_no = version_no
-  end
-
-  def validate_version_sequence! latest
-    if !(latest) && @event_type != 'create'
-      raise "#{ version_class.name } first event must be create"
-    end
-
-    if @event_type == 'create' && latest
-      raise "#{ version_class.name } create event already exists"
-    end
-
-    return unless latest
-
-    if @record.version_no != latest.version_no
-      raise ("#{ record_class.name }##{ @record.id } version_no is #{ @record.version_no }, " +
-             "but latest #{ version_class.name } version_no is #{ latest.version_no }")
-    end
-  end
-
-  def same_snapshot? version, attrs
-    attrs.all? { |k, v| version.public_send(k) == v }
-  end
+  def same_snapshot?(version, attrs) = attrs.all? { |k, v| version.public_send(k) == v }
 
   def validate_event_type!
-    return if event_types.include?(@event_type)
+    return if EVENT_TYPES.include?(@event_type)
 
     raise ArgumentError, "Invalid event_type: #{ @event_type }"
   end
@@ -84,5 +59,4 @@ class VersionRecorder
   def snapshot_attributes = raise NotImplementedError
 
   def record_class = @record.class
-  def event_types = self.class::EVENT_TYPES
 end

backend/app/services/youtube/sync.rb

@@ -1,3 +1,4 @@
+require 'open-uri'
 require 'set'
 require 'time'
 
@@ -126,12 +127,12 @@ module Youtube
       return if post.thumbnail.attached?
       return if thumbnail_url.blank?
 
-      post.attach_thumbnail_from_url!(thumbnail_url)
-    rescue Post::RemoteThumbnailFetchFailed => e
-      Rails.logger.info("youtube_sync_thumbnail_fetch_failed #{ { post_id: post.id,
-                                                                  thumbnail_url:,
-                                                                  error: e.class.name,
-                                                                  message: e.message }.to_json }")
+      post.thumbnail.attach(
+          io:           URI.open(thumbnail_url),
+          filename:     File.basename(URI.parse(thumbnail_url).path),
+          content_type: 'image/jpeg')
+
+      post.resized_thumbnail!
     end
 
     def youtube_url_regexp id