#329

.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。

AGENTS.md

@@ -1,307 +0,0 @@
-# AGENTS.md
-
-## Project overview
-
-BTRC Hub / タグ広場 is a split Rails API and React frontend repository.
-
-- Backend: Rails API under `backend/`.
-- Frontend: React + TypeScript + Vite under `frontend/`.
-- Docs: lightweight command notes under `docs/`.
-- There is no README or Makefile at the repository root as of this inspection.
-
-## Stack
-
-- Backend: Ruby `3.2.2` from `backend/.ruby-version`, Rails `~> 8.0.2`.
-- Backend dependencies include `mysql2`, `sqlite3`, `rspec-rails`,
-  `factory_bot_rails`, `rack-cors`, `jwt`, `discard`, `gollum`, `whenever`,
-  `aws-sdk-s3`, `brakeman`, and `rubocop-rails-omakase`.
-- Frontend: React `^19.1.0`, TypeScript `~5.8.3`, Vite `^6.3.5`.
-- Frontend data/UI dependencies include Axios, TanStack Query, Tailwind CSS,
-  Framer Motion, Radix UI components, lucide-react, MDX/Markdown tooling, and
-  Zustand.
-
-## Main directories
-
-- `backend/app/controllers`: Rails API controllers.
-- `backend/app/models`: Active Record models.
-- `backend/app/representations`: API response representation classes.
-- `backend/app/services`: domain services such as version recording,
-  wiki commit, YouTube sync, and similarity calculation.
-- `backend/config/routes.rb`: API routes.
-- `backend/db/migrate`: migrations.
-- `backend/db/schema.rb`: current schema snapshot.
-- `backend/lib/tasks`: custom Rake tasks.
-- `backend/spec`: RSpec tests.
-- `backend/test`: Rails minitest files that still exist in the tree.
-- `frontend/src/App.tsx`: frontend route definitions and initial user setup.
-- `frontend/src/pages`: page-level React components.
-- `frontend/src/components`: shared and feature components.
-- `frontend/src/lib`: API client helpers, query keys, prefetchers, and domain helpers.
-- `frontend/src/stores`: Zustand stores.
-- `docs/commands.md`: command notes.
-
-## Commands
-
-Only list commands that are backed by files inspected in this repository.
-
-### Backend
-
-The following binstubs exist under `backend/bin`:
-
-```sh
-cd backend
-bin/setup
-bin/dev
-bin/rails
-bin/rake
-bin/rubocop
-bin/brakeman
-bin/kamal
-bin/thrust
-```
-
-Common Rails/Rake usage through existing binstubs:
-
-```sh
-cd backend
-bin/rails db:prepare
-bin/rails db:migrate
-bin/rails routes
-bin/rails server
-bin/rake
-bin/rubocop
-bin/brakeman
-```
-
-RSpec is present in `Gemfile` and `.rspec` exists:
-
-```sh
-cd backend
-bundle exec rspec
-```
-
-### Frontend
-
-The following npm scripts exist in `frontend/package.json`:
-
-```sh
-cd frontend
-npm run dev
-npm run build
-npm run lint
-npm run test
-npm run test:run
-npm run preview
-```
-
-`npm run build` runs `tsc -b && vite build`, then `postbuild` runs
-`node scripts/generate-sitemap.js`.
-
-`npm run test` runs Vitest in watch mode. Use `npm run test:run` for a non-watch frontend test run.
-
-## Coding style
-
-- Prefer precise, minimal changes.
-- Do not flatter or over-explain.
-- Explain risks directly.
-- Prefer single quotes for strings unless interpolation or escaping makes
-  double quotes better.
-- Ruby: never put a space before method-call parentheses.
-- Ruby: `render` 系メソッド呼び出しでは、keyword 引数付きでも括弧を書かない。
-- Ruby: never put a line break immediately before `)`.
-- Ruby: do not use `%w` or `%i`.
-- In Ruby, when an `if` condition is split across multiple lines and combines
-  clauses with `&&` or `||`, wrap the whole condition in parentheses.
-- Ruby hashes are not blocks; keep `}` on the same line as the final pair.
-- Ruby hashes keep the first pair on the same line as `{` unless line length
-  requires a break.
-- 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.
-- Ruby blocks use separate `{ ... }` rules from hashes, with 2-space body
-  indentation.
-- For 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.
-- TypeScript and Python: use GNU-style spacing before parentheses where
-  syntactically valid.
-- Never write Ruby, TypeScript, or TSX lines longer than 99 characters.
-- Aim to keep Ruby, TypeScript, and TSX lines within 79 characters where practical.
-- TypeScript and TSX use 4-space logical indentation.
-- In TypeScript and TSX only, replace every leading run of 8 spaces with a tab.
-- Tabs are only for leading indentation, never for spaces after non-space text.
-- TypeScript and TSX imports may stay on one line if they remain within the
-  line limit; do not expand short type-only imports mechanically.
-- In TypeScript and TSX, when a function takes one destructured object
-  argument plus an inline type, prefer this shape when it fits locally:
-
-```ts
-const helper = (
-    { value, flag }: { value: string
-		       flag:  boolean },
-): Result => {
-  // ...
-}
-```
-
-- In TypeScript and TSX, put `switch` case block braces on their own lines
-  when a case needs a lexical block:
-
-```ts
-case 'yes':
-case 'no':
-  {
-    const expected = valueFor (item)
-    return expected == null || expected === answer
-  }
-```
-
-- In TypeScript and TSX, use `value == null` and `value != null` as the
-  default nullish checks. Do not use `=== null`, `=== undefined`,
-  `!== null`, or `!== undefined`.
-- If code appears to need a distinction between `null` and `undefined`, treat
-  that as a design smell and revise the logic to avoid the distinction.
-  External library APIs that explicitly require distinguishing the two are the
-  only exception.
-- In TypeScript and TSX, keep short arrays on one line when they fit under the
-  line limit; break arrays only when readability or line length requires it.
-- In TypeScript and TSX, when a ternary expression is split across multiple
-  lines, align `?` and `:` with the condition expression. Do not indent `?` and
-  `:` one extra level under the condition.
-
-```ts
-const value =
-    condition
-    ? consequent
-    : alternate
-```
-
-- In TypeScript and TSX, keep short ternary expressions on one line when they
-  fit cleanly under the line limit.
-- In TypeScript and TSX, prefer ternary expressions for simple conditional
-  value selection. Do not replace a clear ternary with `if` statements, and do
-  not introduce immediately invoked functions just to avoid or reformat a
-  ternary expression.
-- In TypeScript and TSX, do not write `let` followed by later `if` assignments
-  when the value can be expressed as a single `const` initializer. Prefer
-  `const` because it prevents accidental later reassignment.
-- When fixing formatting, change formatting only. Do not change expression
-  structure, control flow, or variable mutability unless the requested style
-  explicitly requires it.
-- Do not add production dependencies without explicit approval.
-- 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.
-
-## Backend rules
-
-- Inspect existing routes, controllers, models, services, and specs before
-  editing backend behavior.
-- For API behavior changes, add or update request specs under
-  `backend/spec/requests` only when the user explicitly asks for tests.
-- Prefer RSpec for new backend tests; existing minitest files under
-  `backend/test` do not make minitest the default for new coverage.
-- Do not weaken authentication, BAN user checks, or IP BAN checks.
-- Preserve the `X-Transfer-Code` user identification flow unless the task
-  explicitly changes authentication.
-- Be careful with version tables, `version_no`, optimistic concurrency,
-  wiki revisions, and restore/diff behavior.
-- Be careful with tag names, tag normalization, implications, similarities, and discard behavior.
-- Be sensitive to N+1 queries; avoid introducing them and proactively fix
-  existing N+1 issues in the code path being edited.
-- Keep migration files and `backend/db/schema.rb` consistent when changing schema.
-
-## Frontend rules
-
-- Use `frontend/src/lib/api.ts` for API calls so headers and camelCase conversion stay consistent.
-- Add or reuse TanStack Query keys through `frontend/src/lib/queryKeys.ts`;
-  avoid ad hoc query key arrays.
-- Encode URL path-segment values with `encodeURIComponent`.
-- React hooks must be called unconditionally.
-- Keep page-level code under `frontend/src/pages` and shared UI/feature code
-  under `frontend/src/components` unless existing patterns point elsewhere.
-- Match existing Tailwind, component, and import alias conventions.
-- In TypeScript and TSX, prefer direct comparison operators such as `===` and
-  `!==` over negating a comparison like `!(a === b)`.
-- In TypeScript and TSX, prefer `++i` or `--i` over `i += 1` or `i -= 1` for
-  simple unit-step counter updates.
-- For user-facing Japanese text, prefer modern kana usage and natural current
-  phrasing over historical spellings or awkward literal wording.
-- For user-facing Japanese ellipses, prefer `……` over ASCII `...`.
-
-### Frontend TSX style
-
-- Preserve the local TSX formatting style.
-- Do not normalize TSX to common Prettier-style React formatting unless
-  explicitly asked.
-- Prefer `const` arrow functions for TypeScript/TSX component and helper declarations.
-- Put two blank lines before and after top-level `const` function
-  declarations, unless imports, exports, or file boundaries make that awkward.
-- In TSX, indent with 4-space logical indentation.
-- A leading tab is exactly equivalent to 8 leading spaces.
-- Keep a tag's closing marker on the same line as the final prop when the tag
-  spans multiple lines.
-- Do not put `/>` or `>` on its own line unless the existing surrounding code
-  does so.
-- Keep JSX closing parentheses in the existing compact style, for example
-  `</div>)` rather than moving `)` onto a separate line.
-- Do not add braces around `if`, `else`, or `for` bodies when the body is a
-  single physical line.
-- Always add braces around `if`, `else`, or `for` bodies when the body spans
-  two or more physical lines, even if it is one statement.
-- Do not use a leading semicolon for expression statements such as
-  `;([...]).forEach(...)`; rewrite the expression to avoid ASI hazards
-  explicitly, for example with `void`.
-
-Preferred:
-
-```tsx
-const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
-  return (
-      <TextArea
-	  {...rest}
-	  ref={ref}
-	  value={tags}
-	  invalid={errors && errors.length > 0}
-	  onChange={ev => setTags (ev.target.value)}/>)
-}
-```
-
-Avoid:
-
-```tsx
-function PostFormTagsArea ({ tags, setTags }: Props) {
-  return (
-    <TextArea
-      value={tags}
-      onChange={ev => setTags (ev.target.value)}
-    />
-  )
-}
-```
-
-## Codex workflow
-
-- First inspect existing patterns; do not invent new architecture when a local convention exists.
-- Keep changes scoped to the requested issue.
-- Do not scan or summarize dependency/generated/runtime directories such as
-  `node_modules`, `dist`, `tmp`, `log`, and `storage` unless explicitly needed.
-- Before touching wiki, tag, versioning, BAN, IP BAN, or authentication
-  behavior, inspect the related request specs and service objects.
-- If frontend code changes, run only non-test verification commands that
-  apply, such as `npm run build` and `npm run lint`. Run `npm run test:run`
-  only when the user explicitly asks for tests.
-- If backend code changes, do not run RSpec unless the user explicitly asks
-  for tests.
-- If a verification command cannot be run or fails, report the exact command and failure.
-
-## Completion criteria
-
-A task is complete only when:
-
-- implementation is complete,
-- relevant non-test verification commands pass, or failures are clearly
-  explained,
-- unrelated files are not changed,
-- migrations and schema are consistent when schema changes are made,
-- user-facing behavior is documented when needed.

backend/AGENTS.md

@@ -1,225 +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.
-
-## 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/materials_controller.rb

@@ -40,11 +40,7 @@ class MaterialsController < ApplicationController
     tag_name_raw = params[:tag].to_s.strip
     file = params[: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
+    return head :bad_request if tag_name_raw.blank? || (file.blank? && url.blank?)
 
     tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
     tag = tag_name.tag
@@ -58,7 +54,7 @@ class MaterialsController < ApplicationController
     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
 
@@ -72,11 +68,7 @@ class MaterialsController < ApplicationController
     tag_name_raw = params[:tag].to_s.strip
     file = params[: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
+    return head :bad_request if tag_name_raw.blank? || (file.blank? && url.blank?)
 
     tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
     tag = tag_name.tag
@@ -92,7 +84,7 @@ class MaterialsController < ApplicationController
     if material.save
       render json: MaterialRepr.base(material, host: request.base_url)
     else
-      render_validation_error material
+      render json: { errors: material.errors.full_messages }, status: :unprocessable_entity
     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/posts_controller.rb

@@ -44,8 +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,
-                 tags: [: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
@@ -96,9 +95,7 @@ class PostsController < ApplicationController
   end
 
   def random
-    post = filtered_posts.preload(:uploaded_user, :parents, :children,
-                                  tags: [: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
@@ -107,25 +104,12 @@ class PostsController < ApplicationController
   end
 
   def show
-    post =
-        Post
-        .includes(:uploaded_user, :parents, :children,
-                  tags: [: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: post.related(limit: 20))
   end
 
   def create
@@ -139,39 +123,28 @@ class PostsController < ApplicationController
     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 = Post.new(title:, url:, thumbnail_base: nil, uploaded_user: current_user,
                     original_created_from:, original_created_before:)
-    post.thumbnail.attach(thumbnail) if thumbnail.present?
+    post.thumbnail.attach(thumbnail)
 
     ApplicationRecord.transaction do
       post.save!
-
-      Tag.normalise_tags!(tag_names, deny_deprecated: true, with_sections: true) =>
-          { tags:, sections: }
+      tags = Tag.normalise_tags(tag_names)
       TagVersioning.record_tag_snapshots!(tags, created_by_user: current_user)
 
-      tags = Tag.expand_parent_tags(tags).reject(&:deprecated?)
-      sync_post_tags!(post, tags, sections)
-
-      sync_parent_posts!(post, parent_post_ids)
-
+      tags = Tag.expand_parent_tags(tags)
+      sync_post_tags!(post, tags)
       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 ActiveRecord::RecordInvalid
+    render json: { errors: post.errors.full_messages }, status: :unprocessable_entity
   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 ArgumentError => e
-    render_validation_error fields: { parent_post_ids: [e.message] }
-  rescue ActiveRecord::RecordInvalid => e
-    render_post_form_record_invalid e.record
+    head :bad_request
   end
 
   def viewed
@@ -192,78 +165,35 @@ 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:,
-                                                 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] }
-
-            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
-
-      apply_post_snapshot!(post, snapshot_to_apply)
+      tags = post.tags.nico.to_a + normalised_tags
+      tags = Tag.expand_parent_tags(tags)
+      sync_post_tags!(post, tags)
+      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 ActiveRecord::RecordInvalid
+    render json: post.errors, status: :unprocessable_entity
   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 ArgumentError => e
-    render_validation_error fields: { parent_post_ids: [e.message] }
-  rescue ActiveRecord::RecordInvalid => e
-    render_post_form_record_invalid e.record
+    head :bad_request
   end
 
   def changes
@@ -281,7 +211,7 @@ 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|
@@ -358,7 +288,7 @@ 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
@@ -377,20 +307,13 @@ 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
-    tags = post.tags.reject(&:deprecated?).to_a
+  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)
@@ -405,11 +328,6 @@ class PostsController < ApplicationController
     root_ids = tag_ids - child_ids
 
     tags_by_id = tags.index_by(&:id)
-    sections_by_tag_id =
-        PostTagSection
-        .where(post_id: post.id, tag_id: tag_ids)
-        .order(:begin_ms)
-        .group_by(&:tag_id)
 
     memo = { }
 
@@ -417,11 +335,8 @@ class PostsController < ApplicationController
       tag = tags_by_id[tag_id]
       return nil unless tag
 
-      sections = sections_by_tag_id.fetch(tag_id, [])
-                                   .as_json(only: [:begin_ms, :end_ms])
-
       if path.include?(tag_id)
-        return TagRepr.inline(tag).merge(children: [], sections:)
+        return TagRepr.base(tag).merge(children: [])
       end
 
       if memo.key?(tag_id)
@@ -433,298 +348,9 @@ 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)
-
-    params[:parent_post_ids].to_s.split.map { |token|
-      id = Integer(token, exception: false)
-      raise ArgumentError, "親投稿 Id. が不正です: #{ token }" if !(id) || id <= 0
-
-      id
-    }.uniq
-  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．'
-      raise ActiveRecord::RecordInvalid, post
-    end
-
-    existing_ids = Post.where(id: parent_post_ids).pluck(:id)
-    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(' ') }"
-      raise ActiveRecord::RecordInvalid, post
-    end
-
-    current_ids = post.parent_posts.pluck(:id)
-
-    ids_to_add = parent_post_ids - current_ids
-    ids_to_remove = current_ids - parent_post_ids
-
-    PostImplication.where(post_id: post.id, parent_post_id: ids_to_remove).delete_all
-
-    ids_to_add.each do |parent_post_id|
-      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,
-      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,
-      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:, parent_post_ids:
-    { title:,
-      original_created_from: snapshot_time(original_created_from),
-      original_created_before: snapshot_time(original_created_before),
-      tag_names: incoming_tag_names_for_snapshot(tag_names),
-      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 incoming_tag_names_for_snapshot raw_tag_names
-    Tag.normalise_tags!(raw_tag_names, with_tagme: false, deny_deprecated: true,
-                                        with_sections: true) =>
-        { tags:, sections: }
-
-    Tag.expand_parent_tags(tags).reject(&:deprecated?).uniq(&:id).map { |tag|
-      "#{ tag.name }#{ sections[tag.id].to_a.map { section_literal(_1) }.join }"
-    }.sort
-  end
-
-  def section_literal section
-    "[#{ Post.ms_to_time(section[0]) }-#{ 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(: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],
-                 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?)
-
-    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, :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
 end

backend/app/controllers/preview_controller.rb

@@ -4,7 +4,7 @@ class PreviewController < ApplicationController
     return head :unauthorized unless current_user
 
     url = params[:url]
-    return render_bad_request('URL は必須です．') unless url.present?
+    return head :bad_request unless url.present?
 
     unless url.start_with?(/http(s)?:\/\//)
       url = 'http://' + url
@@ -16,7 +16,7 @@ class PreviewController < ApplicationController
 
     render json: { title: title }
   rescue => e
-    render_bad_request(e.message)
+    render json: { error: e.message }, status: :bad_request
   end
 
   def thumbnail
@@ -25,7 +25,7 @@ class PreviewController < ApplicationController
     return head :unauthorized unless current_user
 
     url = params[:url]
-    return render_bad_request('URL は必須です．') if url.blank?
+    return head :bad_request if url.blank?
 
     unless url.start_with?(/http(s)?:\/\//)
       url = 'http://' + url
@@ -40,11 +40,7 @@ class PreviewController < ApplicationController
       File.delete(path) rescue nil
       send_file image.path, type: 'image/png', disposition: 'inline'
     else
-      render json: { type: 'internal_server_error',
-                     message: 'サムネールを生成できませんでした．',
-                     errors: { },
-                     base_errors: ['サムネールを生成できませんでした．'] },
-             status: :internal_server_error
+      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]
@@ -83,27 +73,37 @@ class TagsController < ApplicationController
     parent_tag_id = params[:parent].to_i
     parent_tag_id = nil if parent_tag_id <= 0
 
-    graph = build_with_depth_graph
-
     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
 
     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: visible_child_tag_ids(tag.id, graph).present?,
-                              children: [])
+      TagRepr.base(tag).merge(has_children: has_children_tag_ids.include?(tag.id), children: [])
     }
   end
 
@@ -129,7 +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 =
@@ -165,7 +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)
@@ -183,52 +182,24 @@ 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?
+    return head :bad_request if name.blank?
 
     tag = Tag.joins(:tag_name)
              .includes(:tag_name, :materials, tag_name: :wiki_page)
@@ -247,26 +218,21 @@ 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?
 
-    if (name != tag.name &&
-        tag.in?([Tag.tagme, Tag.bot, Tag.no_deerjikist, Tag.video, Tag.niconico]))
-      return render_unprocessable_entity 'システム・タグの名称は変更できません．', field: :name
+    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 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
-    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
-    end
-
-    if tag.nico? || category == 'nico'
-      return render_unprocessable_entity 'ニコタグは変更できません．', field: :category
-    end
 
     ApplicationRecord.transaction do
       TagVersioning.ensure_snapshot!(tag, created_by_user: current_user)
@@ -275,11 +241,7 @@ 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
+      tag.update!(category:)
       tag.tag_name.update!(name:)
 
       alias_names << old_name if name_changed
@@ -307,17 +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
-
     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
@@ -329,9 +286,6 @@ class TagsController < ApplicationController
 
       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
 
@@ -348,93 +302,6 @@ class TagsController < ApplicationController
 
   private
 
-  def build_with_depth_graph
-    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
-
-    tags_by_id = Tag.where(id: tag_ids)
-                    .pluck(:id, :category, :deprecated_at)
-                    .each_with_object({ }) do |(id, category, deprecated_at), h|
-      h[id] = { category:, deprecated: deprecated_at.present? }
-    end
-
-    { children_by_parent_id:, parent_ids_by_child_id:, tags_by_id:,
-      visible_child_tag_ids_by_parent_id: { } }
-  end
-
-  def visible_root_tag_ids graph
-    graph[:tags_by_id].filter_map do |tag_id, attrs|
-      next unless with_depth_visible_tag?(attrs)
-      next unless visible_root_tag?(tag_id, graph)
-
-      tag_id
-    end
-  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
-
-    visible_ids << tag_id if with_depth_visible_tag?(tag)
-  end
-
-  def with_depth_visible_tag? tag
-    tag[:category].in?(['meme', 'character', 'material']) && !tag[:deprecated]
-  end
-
   def build_tag_children tag
     material = tag.materials.first
     file = nil
@@ -507,9 +374,9 @@ class TagsController < ApplicationController
   end
 
   def update_parent_tags! tag, parent_names
-    parent_tags = Tag.normalise_tags!(parent_names, with_tagme: false,
-                                                    with_no_deerjikist: false,
-                                                    deny_nico: true)
+    parent_tags = Tag.normalise_tags(parent_names, with_tagme: false,
+                                                   with_no_deerjikist: false,
+                                                   deny_nico: true)
 
     old_parent_tags = tag.parents.to_a
 
@@ -524,40 +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/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/post.rb

@@ -1,48 +1,20 @@
 class Post < ApplicationRecord
   require 'mini_magick'
 
+  belongs_to :parent, class_name: 'Post', optional: true, foreign_key: 'parent_id'
   belongs_to :uploaded_user, class_name: 'User', optional: true
 
   has_many :post_tags, dependent: :destroy, inverse_of: :post
   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',
-           foreign_key: :post_id,
-           dependent: :destroy,
-           inverse_of: :post
-  has_many :parents, through: :parent_post_implications, source: :parent_post
-
-  has_many :child_post_implications,
-           class_name: 'PostImplication',
-           foreign_key: :parent_post_id,
-           dependent: :destroy,
-           inverse_of: :parent_post
-  has_many :children, through: :child_post_implications, source: :post
 
   has_one_attached :thumbnail
 
-  attribute :version_no, :integer, default: 1
-
   before_validation :normalise_url
 
   validates :url, presence: true, uniqueness: true
@@ -50,59 +22,16 @@ class Post < ApplicationRecord
   validate :validate_original_created_range
   validate :url_must_be_http_url
 
-  def parent_posts = parents
-
-  def child_posts = children
-
-  def sibling_posts
-    parent_post_ids = parent_posts.order(:id).pluck(:id)
-
-    parent_post_ids.to_h { [_1, PostImplication.where(parent_post: _1).map(&:post)] }
-  end
-
   def as_json options = { }
-    super(options).merge(thumbnail: thumbnail.attached? ?
-                                    Rails.application.routes.url_helpers.rails_blob_url(
-                                        thumbnail, only_path: false) :
-                                    nil)
+    super(options).merge({ thumbnail: thumbnail.attached? ?
+                                      Rails.application.routes.url_helpers.rails_blob_url(
+                                          thumbnail, only_path: false) :
+                                      nil })
   rescue
     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) }-#{ 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
-
-    if h.positive?
-      '%d:%02d:%02d' % [h, min, s]
-    else
-      '%d:%02d' % [min, s]
-    end
-  end
-
-  def snapshot_parent_post_ids = parents.order(:id).pluck(:id)
+  def snapshot_tag_names = tags.joins(:tag_name).order('tag_names.name').pluck('tag_names.name')
 
   def related limit: nil
     ids = post_similarities.order(cos: :desc)
@@ -138,7 +67,7 @@ class Post < ApplicationRecord
     return if !(f) || !(b)
 
     if f >= b
-      errors.add :original_created_at, 'オリジナルの作成日時の順番がをかしぃです．'
+      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
 

backend/app/models/post_implication.rb

@@ -1,19 +0,0 @@
-class PostImplication < ApplicationRecord
-  self.primary_key = :post_id, :parent_post_id
-
-  belongs_to :post, inverse_of: :parent_post_implications
-  belongs_to :parent_post, class_name: 'Post', inverse_of: :child_post_implications
-
-  validates :post_id, presence: true, uniqueness: { scope: :parent_post_id }
-  validates :parent_post_id, presence: true
-
-  validate :parent_post_mustnt_be_itself
-
-  private
-
-  def parent_post_mustnt_be_itself
-    if parent_post_id == post_id
-      errors.add :parent_post_id, '親投稿に同じ投稿を設定することはできません．'
-    end
-  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, presence: true,
-                     numericality: { only_integer: true, greater_than: :begin_ms }
-end

backend/app/models/tag.rb

@@ -8,15 +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
-
   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'
@@ -49,8 +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
 
@@ -67,7 +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 }
 
@@ -87,72 +75,34 @@ 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)
   def self.video = find_or_create_by_tag_name!('動画', category: :meta)
   def self.niconico = find_or_create_by_tag_name!('ニコニコ', category: :meta)
-  def self.youtube = find_or_create_by_tag_name!('YouTube', category: :meta)
 
-  def self.normalise_tags! tag_names, with_tagme: true,
-                                      with_no_deerjikist: true,
-                                      deny_nico: true,
-                                      deny_deprecated: false,
-                                      with_sections: false
+  def self.normalise_tags tag_names, with_tagme: true,
+                                     with_no_deerjikist: true,
+                                     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|
       pf, cat = CATEGORY_PREFIXES.find { |p, _| name.downcase.start_with?(p) } || ['', nil]
-
-      name = name.sub(/\A#{ pf }/i, '')
-
-      sections_by_tag = []
-      while n = name.sub!(/^(\S*?)\[([0-9:.]*?)-([0-9:.]*?)\](\S*?)$/, '\1\4 \2 \3')
-        name, *section_raw = n.split
-
-        begin_ms, end_ms = section_raw.map { time_to_ms(_1) }
-        next if begin_ms == end_ms
-
-        begin_ms, end_ms = end_ms, begin_ms if begin_ms > end_ms
-
-        sections_by_tag << [begin_ms, end_ms]
-      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)
       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
@@ -273,29 +223,4 @@ 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
-    parts = str.split(':')
-
-    s_part = parts.pop
-    s, ms = s_part.split('.')
-
-    total_s = s.to_i
-
-    if parts.length >= 1
-      total_s += parts.pop.to_i * 60
-    end
-
-    if parts.length >= 1
-      total_s += parts.pop.to_i * 3_600
-    end
-
-    total_s * 1_000 + 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/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

@@ -4,6 +4,7 @@ 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
@@ -18,10 +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/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/post_repr.rb

@@ -2,65 +2,19 @@
 
 
 module PostRepr
-  BASE_FIELDS = [
-      :id,
-      :version_no,
-      :url,
-      :title,
-      :thumbnail_base,
-      :original_created_from,
-      :original_created_before,
-      :created_at,
-      :updated_at
-  ].freeze
+  BASE = { include: { tags: TagRepr::BASE, uploaded_user: UserRepr::BASE } }.freeze
 
   module_function
 
   def base post, current_user = nil
-    json = common(post)
-    json['tags'] = tag_json(post.tags)
-    json['uploaded_user'] = post.uploaded_user && UserRepr.base(post.uploaded_user)
-    json['viewed'] = current_user ? current_user.viewed?(post) : false
-    json
-  end
+    json = post.as_json(BASE)
+    return json.merge(viewed: false) unless current_user
 
-  def detail post, current_user = nil, parent_posts: [], child_posts: [],
-             sibling_posts: { }, related: []
-    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
-
-  def card post
-    common(post).merge('parent_posts' => [], 'child_posts' => [])
-  end
-
-  def cards posts
-    posts.map { |post| card(post) }
+    viewed = current_user.viewed?(post)
+    json.merge(viewed:)
   end
 
   def many posts, current_user = nil
     posts.map { |p| base(p, current_user) }
   end
-
-  def common post
-    BASE_FIELDS.to_h { |field| [field.to_s, post.public_send(field)] }
-               .merge('thumbnail' => thumbnail_url(post))
-  end
-
-  def tag_json tags
-    tags.reject(&:deprecated?).map { |tag| TagRepr.inline(tag) }
-  end
-
-  def thumbnail_url post
-    return nil unless post.thumbnail.attached?
-
-    Rails.application.routes.url_helpers.rails_blob_url(post.thumbnail, only_path: false)
-  rescue
-    nil
-  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/post_version_recorder.rb

@@ -24,7 +24,7 @@ class PostVersionRecorder < VersionRecorder
       url: @record.url,
       thumbnail_base: @record.thumbnail_base,
       tags: @record.snapshot_tag_names.join(' '),
-      parent_post_ids: @record.snapshot_parent_post_ids.join(' '),
+      parent_id: @record.parent_id,
       original_created_from: @record.original_created_from,
       original_created_before: @record.original_created_before }
   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
 
@@ -46,31 +45,7 @@ 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)

backend/app/services/youtube/api_client.rb

@@ -1,73 +0,0 @@
-require 'json'
-require 'net/http'
-require 'uri'
-
-
-module Youtube
-  class ApiClient
-    ENDPOINT = 'https://www.googleapis.com/youtube/v3'
-
-    def initialize api_key: ENV.fetch('YOUTUBE_API_KEY')
-      @api_key = api_key
-    end
-
-    def search_videos q:, published_after: nil, published_before: nil, page_token: nil
-      get_json('/search', {
-          part:           'snippet',
-          type:           'video',
-          q:,
-          order:          'date',
-          maxResults:     50,
-          regionCode:     'JP',
-          relevanceLanguage: 'ja',
-          publishedAfter: published_after&.iso8601,
-          publishedBefore: published_before&.iso8601,
-          pageToken:      page_token }.compact)
-    end
-
-    def videos ids
-      return { 'items' => [] } if ids.empty?
-
-      get_json('/videos', part: 'snippet,status,contentDetails', id: ids.join(','))
-    end
-
-    def playlist_items playlist_id:, page_token: nil
-      get_json('/playlistItems', {
-          part:       'snippet,contentDetails,status',
-          playlistId: playlist_id,
-          maxResults: 50,
-          pageToken:  page_token }.compact)
-    end
-
-    def channel id: nil, handle: nil
-      raise ArgumentError, 'id or handle is required' if id.present? == handle.present?
-
-      params = { part: 'snippet,contentDetails' }
-      params[:id] = id if id.present?
-      params[:forHandle] = handle if handle.present?
-
-      get_json('/channels', params)
-    end
-
-    private
-
-    def get_json path, params
-      uri = URI(ENDPOINT + path)
-      uri.query = URI.encode_www_form(params.merge(key: @api_key))
-
-      response = Net::HTTP.start(uri.host,
-                                 uri.port,
-                                 use_ssl: true,
-                                 open_timeout: 10,
-                                 read_timeout: 30) do |http|
-        http.get(uri)
-      end
-
-      unless response.is_a?(Net::HTTPSuccess)
-        raise "YouTube API error: #{ response.code } #{ response.body }"
-      end
-
-      JSON.parse(response.body)
-    end
-  end
-end

backend/app/services/youtube/sync.rb

@@ -1,168 +0,0 @@
-require 'open-uri'
-require 'set'
-require 'time'
-
-
-module Youtube
-  class Sync
-    def initialize client: ApiClient.new
-      @client = client
-    end
-
-    def sync!
-      video_ids = discover_video_ids
-      return if video_ids.empty?
-
-      video_ids.each_slice(50) do |ids|
-        @client.videos(ids).fetch('items', []).each do |item|
-          sync_video!(VideoItem.new(item))
-        end
-      end
-    end
-
-    private
-
-    def discover_video_ids
-      ids = Set.new
-
-      query_terms.each do |q|
-        response = @client.search_videos(q:, published_after: sync_since)
-
-        response.fetch('items', []).each do |item|
-          video_id = item.dig('id', 'videoId')
-          ids << video_id if video_id.present?
-        end
-      end
-
-      playlist_ids.each do |playlist_id|
-        each_playlist_item(playlist_id) do |item|
-          video_id = item.dig('contentDetails', 'videoId')
-          video_id ||= item.dig('snippet', 'resourceId', 'videoId')
-
-          ids << video_id if video_id.present?
-        end
-      end
-
-      ids.to_a
-    end
-
-    def sync_video! video
-      post = Post.where('url REGEXP ?', youtube_url_regexp(video.id)).first
-
-      original_created_from = video.published_at.change(sec: 0)
-      original_created_before = original_created_from + 1.minute
-
-      post_created = false
-      post_changed = false
-
-      if post
-        post.assign_attributes(title: video.title,
-                               original_created_from:,
-                               original_created_before:,
-                               thumbnail_base: video.thumbnail_url)
-
-        post_changed = post.changed?
-        post.save! if post_changed
-
-        attach_thumbnail_if_needed!(post, video.thumbnail_url)
-      else
-        post_created = true
-        post = Post.create!(
-            title: video.title,
-            url: video.url,
-            thumbnail_base: video.thumbnail_url,
-            uploaded_user_id: nil,
-            original_created_from:,
-            original_created_before:)
-
-        attach_thumbnail_if_needed!(post, video.thumbnail_url)
-
-        sync_post_tags!(post, [Tag.tagme.id, Tag.bot.id, Tag.youtube.id, Tag.video.id])
-      end
-
-      kept_tag_ids = post.tags.pluck(:id).to_set
-      desired_tag_ids = kept_tag_ids.to_a
-
-      deerjikist = Deerjikist.find_by(platform: :youtube, code: video.channel_id)
-      if deerjikist
-        desired_tag_ids.delete(Tag.no_deerjikist.id)
-        desired_tag_ids << deerjikist.tag_id
-      elsif post.tags.where(category: :deerjikist).none?
-        desired_tag_ids << Tag.no_deerjikist.id
-      end
-
-      desired_tag_ids.uniq!
-
-      sync_post_tags!(post, desired_tag_ids, current_tag_ids: kept_tag_ids)
-
-      if post_created
-        PostVersionRecorder.record!(post:, event_type: :create, created_by_user: nil)
-      elsif post_changed || kept_tag_ids != desired_tag_ids.to_set
-        PostVersionRecorder.ensure_snapshot!(post, created_by_user: nil)
-        PostVersionRecorder.record!(post:, event_type: :update, created_by_user: nil)
-      end
-    end
-
-    def sync_post_tags! post, desired_tag_ids, current_tag_ids: nil
-      current_tag_ids ||= PostTag.kept.where(post_id: post.id).pluck(:tag_id).to_set
-      desired_tag_ids = desired_tag_ids.compact.to_set
-
-      to_add = desired_tag_ids - current_tag_ids
-      to_remove = current_tag_ids - desired_tag_ids
-
-      Tag.where(id: to_add.to_a).find_each do |tag|
-        begin
-          PostTag.create!(post:, tag:)
-        rescue ActiveRecord::RecordNotUnique
-          ;
-        end
-      end
-
-      PostTag.where(post_id: post.id, tag_id: to_remove.to_a).kept.find_each do |pt|
-        pt.discard_by!(nil)
-      end
-    end
-
-    def attach_thumbnail_if_needed! post, thumbnail_url
-      return if post.thumbnail.attached?
-      return if thumbnail_url.blank?
-
-      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
-      escaped = Regexp.escape(id)
-      "(youtube\\.com/watch\\?v=#{ escaped }|youtu\\.be/#{ escaped })([^A-Za-z0-9_-]|$)"
-    end
-
-    def query_terms = ['ぼざろクリーチャーシリーズ', '伊地知ニジカ', '伊地知虹鹿']
-
-    def playlist_ids
-      ['PLrOch4zHkI5vu29b-f9umUQQ4tQkuWLPX',
-       'PLrOch4zHkI5vOK0RaytQq6PbucxQkkL0K',
-       'PLrOch4zHkI5tdwm9vSegiDQJOM-hgpcOC']
-    end
-
-    def sync_since = 14.days.ago
-
-    def each_playlist_item playlist_id
-      page_token = nil
-
-      loop do
-        response = @client.playlist_items(playlist_id:, page_token:)
-
-        response.fetch('items', []).each do |item|
-          yield item
-        end
-
-        page_token = response['nextPageToken']
-        break if page_token.blank?
-      end
-    end
-  end
-end

backend/app/services/youtube/video_item.rb

@@ -1,32 +0,0 @@
-require 'time'
-
-
-module Youtube
-  class VideoItem
-    attr_reader :id, :title, :channel_id, :published_at, :thumbnail_url, :raw_tags
-
-    def initialize item
-      snippet = item.fetch('snippet')
-
-      @id = item.fetch('id')
-      @title = snippet['title']
-      @channel_id = snippet['channelId']
-      @published_at = Time.iso8601(snippet['publishedAt'])
-      @thumbnail_url = pick_thumbnail(snippet['thumbnails'] || { })
-      @raw_tags = snippet['tags'] || []
-    end
-
-    def url = "https://www.youtube.com/watch?v=#{ @id }"
-
-    private
-
-    def pick_thumbnail thumbnails
-      ['maxres', 'standard', 'high', 'medium', 'default'].each do |key|
-        url = thumbnails.dig(key, 'url')
-        return url if url.present?
-      end
-
-      nil
-    end
-  end
-end

backend/config/routes.rb

@@ -24,7 +24,6 @@ Rails.application.routes.draw do
       patch '', action: :update
 
       get :deerjikists
-      put :deerjikists, action: :update_deerjikists
     end
   end
 
@@ -63,24 +62,6 @@ Rails.application.routes.draw do
     end
   end
 
-  namespace :gekanator do
-    resources :games, only: [:create], controller: '/gekanator_games' do
-      member do
-        get :extra_questions
-        post :extra_question_answers
-      end
-    end
-    resources :posts, only: [:index], controller: '/gekanator_posts'
-    resources :questions, only: [:index], controller: '/gekanator_questions'
-    resources :question_suggestions,
-              only: [:create],
-              controller: '/gekanator_question_suggestions' do
-      member do
-        post :ai_convert
-      end
-    end
-  end
-
   resources :users, only: [:create, :update] do
     collection do
       post :verify
@@ -103,14 +84,9 @@ Rails.application.routes.draw do
     member do
       put :watching
       patch :next_post
-      put :skip_vote
-      delete :skip_vote, action: :unskip_vote
-      get :post_selection_weights
     end
 
-    resources :comments, controller: :theatre_comments, only: [:index, :create, :destroy]
-    resources :programmes, controller: :theatre_programmes, only: [:index]
-    resources :skip_events, controller: :theatre_skip_events, only: [:index]
+    resources :comments, controller: :theatre_comments, only: [:index, :create]
   end
 
   resources :materials, only: [:index, :show, :create, :update, :destroy]

backend/config/schedule.rb

@@ -17,11 +17,3 @@ every 1.day, at: '0:00 am' do
   rake 'post_similarity:calc', environment: 'production'
   rake 'tag_similarity:calc', environment: 'production'
 end
-
-every 1.day, at: '7:50 am' do
-  rake 'nico:export', environment: 'production'
-end
-
-every :hour do
-  rake 'post:sync', environment: 'production'
-end

backend/db/migrate/20260427214800_create_post_implications.rb

@@ -1,24 +0,0 @@
-class CreatePostImplications < ActiveRecord::Migration[8.0]
-  def up
-    create_table :post_implications, primary_key: [:post_id, :parent_post_id] do |t|
-      t.references :post, null: false, foreign_key: true, index: false
-      t.references :parent_post, null: false, foreign_key: { to_table: :posts }
-      t.timestamps
-
-      t.check_constraint 'post_id <> parent_post_id',
-                         name: 'chk_post_implications_no_self'
-    end
-
-    add_column :post_versions, :parent_post_ids, :text, null: false, after: :parent_id
-    remove_column :post_versions, :parent_id, :bigint
-    remove_reference :posts, :parent, foreign_key: { to_table: :posts }
-  end
-
-  def down
-    add_reference :posts, :parent, foreign_key: { to_table: :posts }, after: :thumbnail_base
-    add_column :post_versions, :parent_id, :bigint, after: :post_id
-    remove_column :post_versions, :parent_post_ids, :text
-
-    drop_table :post_implications
-  end
-end

backend/db/migrate/20260501153900_rename_banned_to_banned_at_in_users_and_ip_addresses.rb

@@ -1,16 +0,0 @@
-class RenameBannedToBannedAtInUsersAndIpAddresses < ActiveRecord::Migration[8.0]
-  def up
-    [:users, :ip_addresses].each do
-      add_column _1, :banned_at, :datetime, after: :banned
-      add_index _1, :banned_at
-      remove_column _1, :banned
-    end
-  end
-
-  def down
-    [:ip_addresses, :users].each do
-      add_column _1, :banned, :boolean, null: false, default: false, after: :banned_at
-      remove_column _1, :banned_at
-    end
-  end
-end

backend/db/migrate/20260507124000_add_version_no_to_posts.rb

@@ -1,27 +0,0 @@
-class AddVersionNoToPosts < ActiveRecord::Migration[8.0]
-  def up
-    add_column :posts, :version_no, :integer
-
-    execute <<~SQL
-      UPDATE
-        posts
-      SET
-        version_no = (
-          SELECT
-            MAX(version_no)
-          FROM
-            post_versions
-          WHERE
-            post_id = posts.id)
-    SQL
-
-    change_column_null :posts, :version_no, false
-
-    add_check_constraint :posts, 'version_no > 0', name: 'chk_posts_version_no_positive'
-  end
-
-  def down
-    remove_check_constraint :posts, name: 'chk_posts_version_no_positive'
-    remove_column :posts, :version_no
-  end
-end

backend/db/migrate/20260507211600_add_version_no_to_tags.rb

@@ -1,37 +0,0 @@
-class AddVersionNoToTags < ActiveRecord::Migration[8.0]
-  def up
-    add_column :tags, :version_no, :integer
-
-    execute <<~SQL
-      UPDATE
-        tags
-      SET
-        version_no = (
-          CASE category
-          WHEN 'nico' THEN
-            (SELECT
-               MAX(version_no)
-             FROM
-               nico_tag_versions
-             WHERE
-               tag_id = tags.id)
-          ELSE
-            (SELECT
-               MAX(version_no)
-             FROM
-               tag_versions
-             WHERE
-               tag_id = tags.id)
-          END)
-    SQL
-
-    change_column_null :tags, :version_no, false
-
-    add_check_constraint :tags, 'version_no > 0', name: 'chk_tags_version_no_positive'
-  end
-
-  def down
-    remove_check_constraint :tags, name: 'chk_tags_version_no_positive'
-    remove_column :tags, :version_no
-  end
-end

backend/db/migrate/20260507213300_add_version_no_to_wiki_pages.rb

@@ -1,27 +0,0 @@
-class AddVersionNoToWikiPages < ActiveRecord::Migration[8.0]
-  def up
-    add_column :wiki_pages, :version_no, :integer
-
-    execute <<~SQL
-      UPDATE
-        wiki_pages
-      SET
-        version_no = (
-          SELECT
-            MAX(version_no)
-          FROM
-            wiki_versions
-          WHERE
-            wiki_page_id = wiki_pages.id)
-    SQL
-
-    change_column_null :wiki_pages, :version_no, false
-
-    add_check_constraint :wiki_pages, 'version_no > 0', name: 'chk_wiki_pages_version_no_positive'
-  end
-
-  def down
-    remove_check_constraint :wiki_pages, name: 'chk_wiki_pages_version_no_positive'
-    remove_column :wiki_pages, :version_no
-  end
-end

backend/db/migrate/20260514221900_create_theatre_programmes.rb

@@ -1,10 +0,0 @@
-class CreateTheatreProgrammes < ActiveRecord::Migration[8.0]
-  def change
-    create_table :theatre_programmes, primary_key: [:theatre_id, :position] do |t|
-      t.references :theatre, null: false, foreign_key: true
-      t.integer :position, null: false
-      t.references :post, null: false, foreign_key: true
-      t.datetime :created_at, null: false
-    end
-  end
-end

backend/db/migrate/20260518235300_create_post_tag_sections.rb

@@ -1,19 +0,0 @@
-class CreatePostTagSections < ActiveRecord::Migration[8.0]
-  def change
-    create_table :post_tag_sections, primary_key: [:post_id, :tag_id, :begin_ms] do |t|
-      t.references :post, null: false, foreign_key: true, index: false
-      t.references :tag, null: false, foreign_key: true, index: false
-      t.integer :begin_ms, null: false
-      t.integer :end_ms, null: false
-      t.timestamps
-
-      t.index [:post_id, :begin_ms], name: 'idx_post_tag_sections_post_id_begin_ms'
-
-      t.check_constraint 'begin_ms >= 0',
-                         name: 'chk_post_tag_sections_begin_ms_natural'
-
-      t.check_constraint 'begin_ms < end_ms',
-                         name: 'chk_post_tag_sections_end_ms_after_begin_ms'
-    end
-  end
-end

backend/db/migrate/20260519013100_add_video_ms_to_posts.rb

@@ -1,9 +0,0 @@
-class AddVideoMsToPosts < ActiveRecord::Migration[8.0]
-  def change
-    add_column :posts, :video_ms, :integer
-    add_index :posts, [:video_ms, :id], name: 'idx_posts_video_ms_id'
-
-    add_check_constraint :posts, 'video_ms IS NULL OR video_ms > 0',
-                         name: 'chk_posts_video_ms_positive'
-  end
-end

backend/db/migrate/20260606000000_create_theatre_skip_votes_and_events.rb

@@ -1,36 +0,0 @@
-class CreateTheatreSkipVotesAndEvents < ActiveRecord::Migration[8.0]
-  def change
-    create_table :theatre_skip_votes, primary_key: [:theatre_id, :post_id, :user_id] do |t|
-      t.references :theatre, null: false, foreign_key: true
-      t.references :post, null: false, foreign_key: true
-      t.references :user, null: false, foreign_key: true
-      t.timestamps
-    end
-
-    create_table :theatre_skip_events do |t|
-      t.references :theatre, null: false, foreign_key: true
-      t.references :post, null: false, foreign_key: true
-      t.references :skipped_by_user, null: false, foreign_key: { to_table: :users }
-      t.integer :programme_position
-      t.datetime :created_at, null: false
-    end
-
-    create_table :theatre_skip_event_voters, primary_key: [:theatre_skip_event_id, :user_id] do |t|
-      t.references :theatre_skip_event, null: false, foreign_key: true
-      t.references :user, null: false, foreign_key: true
-    end
-
-    create_table :theatre_skip_event_tags, primary_key: [:theatre_skip_event_id, :tag_id] do |t|
-      t.references :theatre_skip_event, null: false, foreign_key: true
-      t.references :tag, null: false, foreign_key: true
-    end
-
-    add_index :theatre_skip_events, [:theatre_id, :created_at]
-    add_index :theatre_skip_votes, [:theatre_id, :post_id, :created_at],
-              name: 'idx_theatre_skip_votes_theatre_post_created'
-    add_index :theatre_skip_event_voters, [:user_id, :theatre_skip_event_id],
-              name: 'idx_theatre_skip_event_voters_user_event'
-    add_index :theatre_skip_event_tags, [:tag_id, :theatre_skip_event_id],
-              name: 'idx_theatre_skip_event_tags_tag_event'
-  end
-end

backend/db/migrate/20260607000000_create_gekanator_games.rb

@@ -1,18 +0,0 @@
-class CreateGekanatorGames < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_games do |t|
-      t.references :user, null: false, foreign_key: true
-      t.references :guessed_post, null: false, foreign_key: { to_table: :posts }
-      t.references :correct_post, null: false, foreign_key: { to_table: :posts }
-      t.boolean :won, null: false
-      t.integer :question_count, null: false
-      t.json :answers, null: false
-
-      t.timestamps
-    end
-
-    add_check_constraint :gekanator_games,
-                         'question_count >= 0',
-                         name: 'chk_gekanator_games_question_count_nonnegative'
-  end
-end

backend/db/migrate/20260608000000_create_gekanator_question_suggestions.rb

@@ -1,14 +0,0 @@
-class CreateGekanatorQuestionSuggestions < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_question_suggestions do |t|
-      t.references :gekanator_game,
-                   null: false,
-                   foreign_key: { on_delete: :cascade }
-      t.references :user, null: false, foreign_key: true
-      t.text :question_text, null: false
-      t.boolean :processed, null: false, default: false
-
-      t.timestamps
-    end
-  end
-end

backend/db/migrate/20260608002000_add_answer_to_gekanator_question_suggestions.rb

@@ -1,5 +0,0 @@
-class AddAnswerToGekanatorQuestionSuggestions < ActiveRecord::Migration[8.0]
-  def change
-    add_column :gekanator_question_suggestions, :answer, :string, null: false
-  end
-end

backend/db/migrate/20260609000000_create_gekanator_questions.rb

@@ -1,19 +0,0 @@
-class CreateGekanatorQuestions < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_questions do |t|
-      t.string :text, null: false
-      t.string :kind, null: false
-      t.json :condition, null: false
-      t.string :source, null: false, default: 'ai_generated'
-      t.string :status, null: false, default: 'pending'
-      t.float :priority_weight, null: false, default: 1.0
-      t.references :gekanator_question_suggestion,
-                   null: true,
-                   foreign_key: true
-      t.references :created_by,
-                   null: true,
-                   foreign_key: { to_table: :users }
-      t.timestamps
-    end
-  end
-end

backend/db/migrate/20260609001000_create_gekanator_ai_runs.rb

@@ -1,13 +0,0 @@
-class CreateGekanatorAiRuns < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_ai_runs do |t|
-      t.string :model, null: false
-      t.integer :input_tokens, null: false, default: 0
-      t.integer :output_tokens, null: false, default: 0
-      t.decimal :estimated_cost_jpy, precision: 8, scale: 3, null: false, default: 0
-      t.string :status, null: false, default: 'pending'
-      t.references :gekanator_question_suggestion, null: false, foreign_key: true
-      t.timestamps
-    end
-  end
-end

backend/db/migrate/20260610000000_create_gekanator_question_examples.rb

@@ -1,19 +0,0 @@
-class CreateGekanatorQuestionExamples < ActiveRecord::Migration[8.0]
-  def change
-    create_table :gekanator_question_examples do |t|
-      t.references :gekanator_question, null: false, foreign_key: true
-      t.references :post, null: false, foreign_key: true
-      t.references :user, null: false, foreign_key: true
-      t.references :gekanator_game, null: true, foreign_key: true
-      t.string :answer, null: false
-      t.string :source, null: false, default: 'post_game_extra'
-      t.float :weight, null: false, default: 1.0
-      t.timestamps
-    end
-
-    add_index :gekanator_question_examples,
-              [:gekanator_question_id, :post_id, :user_id],
-              unique: true,
-              name: 'idx_gekanator_question_examples_on_question_post_user'
-  end
-end

backend/db/migrate/20260612000000_add_answer_statistics_to_gekanator_question_examples.rb

@@ -1,40 +0,0 @@
-class AddAnswerStatisticsToGekanatorQuestionExamples < ActiveRecord::Migration[8.0]
-  class MigrationGekanatorQuestionExample < ApplicationRecord
-    self.table_name = 'gekanator_question_examples'
-  end
-
-  def up
-    add_column :gekanator_question_examples,
-               :answer_counts,
-               :json,
-               null: true
-    add_column :gekanator_question_examples,
-               :sample_count,
-               :integer,
-               null: false,
-               default: 1
-
-    MigrationGekanatorQuestionExample.reset_column_information
-    MigrationGekanatorQuestionExample.find_each do |example|
-      counts = {
-        'yes' => 0,
-        'no' => 0,
-        'partial' => 0,
-        'probably_no' => 0,
-        'unknown' => 0
-      }
-      counts[example.answer] = 1 if counts.key?(example.answer)
-
-      example.update_columns(
-        answer_counts: counts,
-        sample_count: 1)
-    end
-
-    change_column_null :gekanator_question_examples, :answer_counts, false
-  end
-
-  def down
-    remove_column :gekanator_question_examples, :sample_count
-    remove_column :gekanator_question_examples, :answer_counts
-  end
-end

backend/db/migrate/20260621000000_add_deprecated_at_to_tags.rb

@@ -1,20 +0,0 @@
-class AddDeprecatedAtToTags < ActiveRecord::Migration[8.0]
-  def up
-    add_column :tags, :deprecated_at, :datetime, after: :category
-    add_column :tag_versions, :deprecated_at, :datetime, after: :parent_tag_ids
-
-    add_index :tags, :deprecated_at
-
-    add_check_constraint :tags, "deprecated_at IS NULL OR category <> 'nico'",
-                         name: 'chk_tags_deprecated_at_not_nico'
-  end
-
-  def down
-    remove_check_constraint :tags, name: 'chk_tags_deprecated_at_not_nico'
-
-    remove_index :tags, :deprecated_at
-
-    remove_column :tag_versions, :deprecated_at, :datetime
-    remove_column :tags, :deprecated_at
-  end
-end

backend/db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
+ActiveRecord::Schema[8.0].define(version: 2026_04_26_120600) do
   create_table "active_storage_attachments", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -48,85 +48,11 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.index ["tag_id"], name: "index_deerjikists_on_tag_id"
   end
 
-  create_table "gekanator_ai_runs", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.string "model", null: false
-    t.integer "input_tokens", default: 0, null: false
-    t.integer "output_tokens", default: 0, null: false
-    t.decimal "estimated_cost_jpy", precision: 8, scale: 3, default: "0.0", null: false
-    t.string "status", default: "pending", null: false
-    t.bigint "gekanator_question_suggestion_id", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["gekanator_question_suggestion_id"], name: "index_gekanator_ai_runs_on_gekanator_question_suggestion_id"
-  end
-
-  create_table "gekanator_games", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "user_id", null: false
-    t.bigint "guessed_post_id", null: false
-    t.bigint "correct_post_id", null: false
-    t.boolean "won", null: false
-    t.integer "question_count", null: false
-    t.json "answers", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["correct_post_id"], name: "index_gekanator_games_on_correct_post_id"
-    t.index ["guessed_post_id"], name: "index_gekanator_games_on_guessed_post_id"
-    t.index ["user_id"], name: "index_gekanator_games_on_user_id"
-    t.check_constraint "`question_count` >= 0", name: "chk_gekanator_games_question_count_nonnegative"
-  end
-
-  create_table "gekanator_question_examples", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "gekanator_question_id", null: false
-    t.bigint "post_id", null: false
-    t.bigint "user_id", null: false
-    t.bigint "gekanator_game_id"
-    t.string "answer", null: false
-    t.string "source", default: "post_game_extra", null: false
-    t.float "weight", default: 1.0, null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.json "answer_counts", null: false
-    t.integer "sample_count", default: 1, null: false
-    t.index ["gekanator_game_id"], name: "index_gekanator_question_examples_on_gekanator_game_id"
-    t.index ["gekanator_question_id", "post_id", "user_id"], name: "idx_gekanator_question_examples_on_question_post_user", unique: true
-    t.index ["gekanator_question_id"], name: "index_gekanator_question_examples_on_gekanator_question_id"
-    t.index ["post_id"], name: "index_gekanator_question_examples_on_post_id"
-    t.index ["user_id"], name: "index_gekanator_question_examples_on_user_id"
-  end
-
-  create_table "gekanator_question_suggestions", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "gekanator_game_id", null: false
-    t.bigint "user_id", null: false
-    t.text "question_text", null: false
-    t.boolean "processed", default: false, null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.string "answer", null: false
-    t.index ["gekanator_game_id"], name: "index_gekanator_question_suggestions_on_gekanator_game_id"
-    t.index ["user_id"], name: "index_gekanator_question_suggestions_on_user_id"
-  end
-
-  create_table "gekanator_questions", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.string "text", null: false
-    t.string "kind", null: false
-    t.json "condition", null: false
-    t.string "source", default: "ai_generated", null: false
-    t.string "status", default: "pending", null: false
-    t.float "priority_weight", default: 1.0, null: false
-    t.bigint "gekanator_question_suggestion_id"
-    t.bigint "created_by_id"
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["created_by_id"], name: "index_gekanator_questions_on_created_by_id"
-    t.index ["gekanator_question_suggestion_id"], name: "index_gekanator_questions_on_gekanator_question_suggestion_id"
-  end
-
   create_table "ip_addresses", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.binary "ip_address", limit: 16, null: false
-    t.datetime "banned_at"
+    t.boolean "banned", default: false, null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.index ["banned_at"], name: "index_ip_addresses_on_banned_at"
     t.index ["ip_address"], name: "index_ip_addresses_on_ip_address", unique: true
   end
 
@@ -193,15 +119,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.check_constraint "`version_no` > 0", name: "nico_tag_versions_version_no_positive"
   end
 
-  create_table "post_implications", primary_key: ["post_id", "parent_post_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "post_id", null: false
-    t.bigint "parent_post_id", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["parent_post_id"], name: "index_post_implications_on_parent_post_id"
-    t.check_constraint "`post_id` <> `parent_post_id`", name: "chk_post_implications_no_self"
-  end
-
   create_table "post_similarities", primary_key: ["post_id", "target_post_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "post_id", null: false
     t.bigint "target_post_id", null: false
@@ -210,19 +127,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.index ["target_post_id"], name: "index_post_similarities_on_target_post_id"
   end
 
-  create_table "post_tag_sections", primary_key: ["post_id", "tag_id", "begin_ms"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "post_id", null: false
-    t.bigint "tag_id", null: false
-    t.integer "begin_ms", null: false
-    t.integer "end_ms", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["post_id", "begin_ms"], name: "idx_post_tag_sections_post_id_begin_ms"
-    t.index ["tag_id"], name: "fk_rails_8be3847903"
-    t.check_constraint "`begin_ms` < `end_ms`", name: "chk_post_tag_sections_end_ms_after_begin_ms"
-    t.check_constraint "`begin_ms` >= 0", name: "chk_post_tag_sections_begin_ms_natural"
-  end
-
   create_table "post_tags", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "post_id", null: false
     t.bigint "tag_id", null: false
@@ -251,12 +155,13 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.string "url", limit: 768, null: false
     t.string "thumbnail_base", limit: 2000
     t.text "tags", null: false
-    t.text "parent_post_ids", null: false
+    t.bigint "parent_id"
     t.datetime "original_created_from"
     t.datetime "original_created_before"
     t.datetime "created_at", null: false
     t.bigint "created_by_user_id"
     t.index ["created_by_user_id"], name: "index_post_versions_on_created_by_user_id"
+    t.index ["parent_id"], name: "index_post_versions_on_parent_id"
     t.index ["post_id", "version_no"], name: "index_post_versions_on_post_id_and_version_no", unique: true
     t.index ["post_id"], name: "index_post_versions_on_post_id"
     t.check_constraint "`event_type` in (_utf8mb4'create',_utf8mb4'update',_utf8mb4'discard',_utf8mb4'restore')", name: "post_versions_event_type_valid"
@@ -267,18 +172,15 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.string "title"
     t.string "url", limit: 768, null: false
     t.string "thumbnail_base", limit: 2000
+    t.bigint "parent_id"
     t.bigint "uploaded_user_id"
     t.datetime "created_at", null: false
     t.datetime "original_created_from"
     t.datetime "original_created_before"
     t.datetime "updated_at", null: false
-    t.integer "version_no", null: false
-    t.integer "video_ms"
+    t.index ["parent_id"], name: "index_posts_on_parent_id"
     t.index ["uploaded_user_id"], name: "index_posts_on_uploaded_user_id"
     t.index ["url"], name: "index_posts_on_url", unique: true
-    t.index ["video_ms", "id"], name: "idx_posts_video_ms_id"
-    t.check_constraint "(`video_ms` is null) or (`video_ms` > 0)", name: "chk_posts_video_ms_positive"
-    t.check_constraint "`version_no` > 0", name: "chk_posts_version_no_positive"
   end
 
   create_table "settings", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -335,7 +237,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.string "event_type", null: false
     t.string "name", null: false
     t.string "category", null: false
-    t.datetime "deprecated_at"
     t.text "aliases", null: false
     t.text "parent_tag_ids", null: false
     t.datetime "created_at", null: false
@@ -353,14 +254,9 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.integer "post_count", default: 0, null: false
-    t.datetime "deprecated_at"
     t.datetime "discarded_at"
-    t.integer "version_no", null: false
-    t.index ["deprecated_at"], name: "index_tags_on_deprecated_at"
     t.index ["discarded_at"], name: "index_tags_on_discarded_at"
     t.index ["tag_name_id"], name: "index_tags_on_tag_name_id", unique: true
-    t.check_constraint "(`deprecated_at` is null) or (`category` <> _utf8mb4'nico')", name: "chk_tags_deprecated_at_not_nico"
-    t.check_constraint "`version_no` > 0", name: "chk_tags_version_no_positive"
   end
 
   create_table "theatre_comments", primary_key: ["theatre_id", "no"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -376,55 +272,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.index ["user_id"], name: "index_theatre_comments_on_user_id"
   end
 
-  create_table "theatre_programmes", primary_key: ["theatre_id", "position"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_id", null: false
-    t.integer "position", null: false
-    t.bigint "post_id", null: false
-    t.datetime "created_at", null: false
-    t.index ["post_id"], name: "index_theatre_programmes_on_post_id"
-    t.index ["theatre_id"], name: "index_theatre_programmes_on_theatre_id"
-  end
-
-  create_table "theatre_skip_event_tags", primary_key: ["theatre_skip_event_id", "tag_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_skip_event_id", null: false
-    t.bigint "tag_id", null: false
-    t.index ["tag_id", "theatre_skip_event_id"], name: "idx_theatre_skip_event_tags_tag_event"
-    t.index ["tag_id"], name: "index_theatre_skip_event_tags_on_tag_id"
-    t.index ["theatre_skip_event_id"], name: "index_theatre_skip_event_tags_on_theatre_skip_event_id"
-  end
-
-  create_table "theatre_skip_event_voters", primary_key: ["theatre_skip_event_id", "user_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_skip_event_id", null: false
-    t.bigint "user_id", null: false
-    t.index ["theatre_skip_event_id"], name: "index_theatre_skip_event_voters_on_theatre_skip_event_id"
-    t.index ["user_id", "theatre_skip_event_id"], name: "idx_theatre_skip_event_voters_user_event"
-    t.index ["user_id"], name: "index_theatre_skip_event_voters_on_user_id"
-  end
-
-  create_table "theatre_skip_events", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_id", null: false
-    t.bigint "post_id", null: false
-    t.bigint "skipped_by_user_id", null: false
-    t.integer "programme_position"
-    t.datetime "created_at", null: false
-    t.index ["post_id"], name: "index_theatre_skip_events_on_post_id"
-    t.index ["skipped_by_user_id"], name: "index_theatre_skip_events_on_skipped_by_user_id"
-    t.index ["theatre_id", "created_at"], name: "index_theatre_skip_events_on_theatre_id_and_created_at"
-    t.index ["theatre_id"], name: "index_theatre_skip_events_on_theatre_id"
-  end
-
-  create_table "theatre_skip_votes", primary_key: ["theatre_id", "post_id", "user_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
-    t.bigint "theatre_id", null: false
-    t.bigint "post_id", null: false
-    t.bigint "user_id", null: false
-    t.datetime "created_at", null: false
-    t.datetime "updated_at", null: false
-    t.index ["post_id"], name: "index_theatre_skip_votes_on_post_id"
-    t.index ["theatre_id", "post_id", "created_at"], name: "idx_theatre_skip_votes_theatre_post_created"
-    t.index ["theatre_id"], name: "index_theatre_skip_votes_on_theatre_id"
-    t.index ["user_id"], name: "index_theatre_skip_votes_on_user_id"
-  end
-
   create_table "theatre_watching_users", primary_key: ["theatre_id", "user_id"], charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
     t.bigint "theatre_id", null: false
     t.bigint "user_id", null: false
@@ -432,7 +279,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.index ["expires_at"], name: "index_theatre_watching_users_on_expires_at"
-    t.index ["theatre_id", "expires_at"], name: "idx_on_theatre_id_skip_expires_at_4c8de1dd42"
     t.index ["theatre_id", "expires_at"], name: "index_theatre_watching_users_on_theatre_id_and_expires_at"
     t.index ["theatre_id"], name: "index_theatre_watching_users_on_theatre_id"
     t.index ["user_id"], name: "index_theatre_watching_users_on_user_id"
@@ -480,10 +326,9 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.string "name"
     t.string "inheritance_code", limit: 64, null: false
     t.string "role", null: false
-    t.datetime "banned_at"
+    t.boolean "banned", default: false, null: false
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.index ["banned_at"], name: "index_users_on_banned_at"
   end
 
   create_table "wiki_assets", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -516,12 +361,10 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
     t.datetime "updated_at", null: false
     t.datetime "discarded_at"
     t.integer "next_asset_no", default: 1, null: false
-    t.integer "version_no", null: false
     t.index ["created_user_id"], name: "index_wiki_pages_on_created_user_id"
     t.index ["discarded_at"], name: "index_wiki_pages_on_discarded_at"
     t.index ["tag_name_id"], name: "index_wiki_pages_on_tag_name_id", unique: true
     t.index ["updated_user_id"], name: "index_wiki_pages_on_updated_user_id"
-    t.check_constraint "`version_no` > 0", name: "chk_wiki_pages_version_no_positive"
   end
 
   create_table "wiki_revision_lines", charset: "utf8mb4", collation: "utf8mb4_0900_ai_ci", force: :cascade do |t|
@@ -572,18 +415,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
 
   add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
   add_foreign_key "active_storage_variant_records", "active_storage_blobs", column: "blob_id"
-  add_foreign_key "gekanator_ai_runs", "gekanator_question_suggestions"
-  add_foreign_key "gekanator_games", "posts", column: "correct_post_id"
-  add_foreign_key "gekanator_games", "posts", column: "guessed_post_id"
-  add_foreign_key "gekanator_games", "users"
-  add_foreign_key "gekanator_question_examples", "gekanator_games"
-  add_foreign_key "gekanator_question_examples", "gekanator_questions"
-  add_foreign_key "gekanator_question_examples", "posts"
-  add_foreign_key "gekanator_question_examples", "users"
-  add_foreign_key "gekanator_question_suggestions", "gekanator_games", on_delete: :cascade
-  add_foreign_key "gekanator_question_suggestions", "users"
-  add_foreign_key "gekanator_questions", "gekanator_question_suggestions"
-  add_foreign_key "gekanator_questions", "users", column: "created_by_id"
   add_foreign_key "material_versions", "materials"
   add_foreign_key "material_versions", "materials", column: "parent_id"
   add_foreign_key "material_versions", "tags"
@@ -597,18 +428,16 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
   add_foreign_key "nico_tag_relations", "tags", column: "nico_tag_id"
   add_foreign_key "nico_tag_versions", "tags"
   add_foreign_key "nico_tag_versions", "users", column: "created_by_user_id"
-  add_foreign_key "post_implications", "posts"
-  add_foreign_key "post_implications", "posts", column: "parent_post_id"
   add_foreign_key "post_similarities", "posts"
   add_foreign_key "post_similarities", "posts", column: "target_post_id"
-  add_foreign_key "post_tag_sections", "posts"
-  add_foreign_key "post_tag_sections", "tags"
   add_foreign_key "post_tags", "posts"
   add_foreign_key "post_tags", "tags"
   add_foreign_key "post_tags", "users", column: "created_user_id"
   add_foreign_key "post_tags", "users", column: "deleted_user_id"
   add_foreign_key "post_versions", "posts"
+  add_foreign_key "post_versions", "posts", column: "parent_id"
   add_foreign_key "post_versions", "users", column: "created_by_user_id"
+  add_foreign_key "posts", "posts", column: "parent_id"
   add_foreign_key "posts", "users", column: "uploaded_user_id"
   add_foreign_key "settings", "users"
   add_foreign_key "tag_implications", "tags"
@@ -621,18 +450,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_06_21_000000) do
   add_foreign_key "tags", "tag_names"
   add_foreign_key "theatre_comments", "theatres"
   add_foreign_key "theatre_comments", "users"
-  add_foreign_key "theatre_programmes", "posts"
-  add_foreign_key "theatre_programmes", "theatres"
-  add_foreign_key "theatre_skip_event_tags", "tags"
-  add_foreign_key "theatre_skip_event_tags", "theatre_skip_events"
-  add_foreign_key "theatre_skip_event_voters", "theatre_skip_events"
-  add_foreign_key "theatre_skip_event_voters", "users"
-  add_foreign_key "theatre_skip_events", "posts"
-  add_foreign_key "theatre_skip_events", "theatres"
-  add_foreign_key "theatre_skip_events", "users", column: "skipped_by_user_id"
-  add_foreign_key "theatre_skip_votes", "posts"
-  add_foreign_key "theatre_skip_votes", "theatres"
-  add_foreign_key "theatre_skip_votes", "users"
   add_foreign_key "theatre_watching_users", "theatres"
   add_foreign_key "theatre_watching_users", "users"
   add_foreign_key "theatres", "posts", column: "current_post_id"

backend/lib/tasks/calc_post_similarities.rake

@@ -1,6 +1,6 @@
 namespace :post_similarity do
   desc '関聯投稿テーブル作成'
   task calc: :environment do
-    Similarity::Calc.call(Post, :active_tags)
+    Similarity::Calc.call(Post, :tags)
   end
 end

backend/lib/tasks/calc_tag_similarities.rake

@@ -1,6 +1,6 @@
 namespace :tag_similarity do
   desc '関聯タグ・テーブル作成'
   task calc: :environment do
-    Similarity::Calc.call(Tag, :posts, scope: Tag.where(deprecated_at: nil))
+    Similarity::Calc.call(Tag, :posts)
   end
 end

backend/lib/tasks/sync_posts.rake

@@ -1,6 +0,0 @@
-namespace :post do
-  desc '投稿同期（ニコニコ以外）'
-  task sync: :environment do
-    Youtube::Sync.new.sync!
-  end
-end

backend/spec/factories/ip_addresses.rb

@@ -1,10 +0,0 @@
-FactoryBot.define do
-  factory :ip_address do
-    ip_address { IPAddr.new('203.0.113.10').hton }
-    banned_at { nil }
-
-    trait :banned do
-      banned_at { Time.current }
-    end
-  end
-end

backend/spec/factories/post_tag_sections.rb

@@ -1,8 +0,0 @@
-FactoryBot.define do
-  factory :post_tag_section do
-    association :post
-    association :tag
-    begin_ms { 1_000 }
-    end_ms { 2_000 }
-  end
-end

backend/spec/factories/post_tags.rb

@@ -1,6 +0,0 @@
-FactoryBot.define do
-  factory :post_tag do
-    association :post
-    association :tag
-  end
-end

backend/spec/factories/posts.rb

@@ -1,8 +0,0 @@
-FactoryBot.define do
-  factory :post do
-    sequence(:url) { |n| "https://example.com/factory-post-#{ n }" }
-    title { 'factory post' }
-    thumbnail_base { nil }
-    uploaded_user { nil }
-  end
-end

backend/spec/factories/users.rb

@@ -1,24 +1,15 @@
 FactoryBot.define do
   factory :user do
-    name { nil }
+    name { "test-user" }
     inheritance_code { SecureRandom.uuid }
-    role { 'guest' }
-    banned_at { nil }
-
-    trait :guest do
-      role { 'guest' }
-    end
+    role { "guest" }
 
     trait :member do
-      role { 'member' }
+      role { "member" }
     end
 
     trait :admin do
       role { 'admin' }
     end
-
-    trait :banned do
-      banned_at { Time.current }
-    end
   end
 end

backend/spec/models/post_implication_spec.rb

@@ -1,51 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe PostImplication, type: :model do
-  let!(:post_record) do
-    Post.create!(
-      title: 'post',
-      url: 'https://example.com/post-implication-post'
-    )
-  end
-
-  let!(:parent_post) do
-    Post.create!(
-      title: 'parent post',
-      url: 'https://example.com/post-implication-parent'
-    )
-  end
-
-  it 'is valid with post and parent_post' do
-    implication = described_class.new(
-      post: post_record,
-      parent_post:
-    )
-
-    expect(implication).to be_valid
-  end
-
-  it 'does not allow same post as parent_post' do
-    implication = described_class.new(
-      post: post_record,
-      parent_post: post_record
-    )
-
-    expect(implication).not_to be_valid
-    expect(implication.errors[:parent_post_id]).to be_present
-  end
-
-  it 'does not allow duplicate pair' do
-    described_class.create!(
-      post: post_record,
-      parent_post:
-    )
-
-    duplicate = described_class.new(
-      post: post_record,
-      parent_post:
-    )
-
-    expect(duplicate).not_to be_valid
-    expect(duplicate.errors[:post_id]).to be_present
-  end
-end

backend/spec/models/post_tag_spec.rb

@@ -1,29 +0,0 @@
-RSpec.describe PostTag, type: :model do
-  describe '#sections' do
-    it 'loads sections by post_id and tag_id' do
-      post_tag = create(:post_tag)
-      section = create(:post_tag_section,
-                       post: post_tag.post,
-                       tag: post_tag.tag,
-                       begin_ms: 1000,
-                       end_ms: 2000)
-
-      expect(post_tag.sections).to contain_exactly(section)
-    end
-
-    it 'does not load sections for another tag on the same post' do
-      post = create(:post)
-      tag = create(:tag)
-      other_tag = create(:tag)
-
-      post_tag = create(:post_tag, post:, tag:)
-      create(:post_tag_section,
-             post:,
-             tag: other_tag,
-             begin_ms: 1000,
-             end_ms: 2000)
-
-      expect(post_tag.sections).to be_empty
-    end
-  end
-end

backend/spec/models/post_version_spec.rb

@@ -19,7 +19,7 @@ RSpec.describe PostVersion, type: :model do
       url: post_record.url,
       thumbnail_base: post_record.thumbnail_base,
       tags: post_record.snapshot_tag_names.join(' '),
-      parent_post_ids: post_record.snapshot_parent_post_ids.join(' '),
+      parent: post_record.parent,
       original_created_from: post_record.original_created_from,
       original_created_before: post_record.original_created_before,
       created_at: Time.current,

backend/spec/models/tag_name_sanitisation_rule_spec.rb

@@ -1,10 +1,6 @@
 require 'rails_helper'
 
 RSpec.describe TagNameSanitisationRule, type: :model do
-  before do
-    described_class.unscoped.delete_all
-  end
-
   describe '.sanitise' do
     before do
       described_class.create!(priority: 10, source_pattern: '_', replacement: '')

backend/spec/models/tag_spec.rb

@@ -1,79 +1,6 @@
 require 'rails_helper'
 
 RSpec.describe Tag, type: :model do
-  describe '.normalise_tags!' do
-    it 'rejects deprecated tags when deny_deprecated is enabled' do
-      tag_name = TagName.create!(name: 'normalise deprecated tag')
-      deprecated_tag = Tag.create!(
-        tag_name:,
-        category: :general,
-        deprecated_at: 1.day.from_now
-      )
-
-      expect {
-        described_class.normalise_tags!(
-          [deprecated_tag.name],
-          deny_deprecated: true
-        )
-      }.to raise_error(Tag::DeprecatedTagNormalisationError) { |error|
-        expect(error.tag_names).to eq([deprecated_tag.name])
-      }
-    end
-  end
-
-  describe '.expand_parent_tags' do
-    it 'expands through multiple deprecated parents to an active ancestor' do
-      child = create(:tag, name: 'expand_child')
-      deprecated_parent = create(
-        :tag,
-        name: 'expand_deprecated_parent',
-        deprecated_at: Time.current
-      )
-      deprecated_grandparent = create(
-        :tag,
-        name: 'expand_deprecated_grandparent',
-        deprecated_at: Time.current
-      )
-      active_ancestor = create(:tag, name: 'expand_active_ancestor')
-      TagImplication.create!(tag: child, parent_tag: deprecated_parent)
-      TagImplication.create!(tag: deprecated_parent, parent_tag: deprecated_grandparent)
-      TagImplication.create!(tag: deprecated_grandparent, parent_tag: active_ancestor)
-
-      expanded = described_class.expand_parent_tags([child])
-
-      expect(expanded).to include(
-        child,
-        deprecated_parent,
-        deprecated_grandparent,
-        active_ancestor
-      )
-      expect(expanded.reject(&:deprecated?)).to contain_exactly(child, active_ancestor)
-    end
-
-    it 'terminates when implications contain a cycle' do
-      first = create(:tag, name: 'expand_cycle_first')
-      second = create(:tag, name: 'expand_cycle_second')
-      TagImplication.create!(tag: first, parent_tag: second)
-      TagImplication.create!(tag: second, parent_tag: first)
-
-      expect(described_class.expand_parent_tags([first])).to contain_exactly(first, second)
-    end
-  end
-
-  describe 'deprecated validation' do
-    it 'rejects deprecated nico tags' do
-      tag = build(
-        :tag,
-        name: 'nico:deprecated_validation',
-        category: :nico,
-        deprecated_at: Time.current
-      )
-
-      expect(tag).not_to be_valid
-      expect(tag.errors[:deprecated_at]).to include('ニコタグは廃止できません．')
-    end
-  end
-
   describe '.merge_tags!' do
     let!(:target_tag) { create(:tag, category: :general) }
     let!(:source_tag) { create(:tag, category: :general) }
@@ -234,7 +161,7 @@ RSpec.describe Tag, type: :model do
         url: post.url,
         thumbnail_base: post.thumbnail_base,
         tags: snapshot_tags(post),
-        parent_post_ids: post.snapshot_parent_post_ids.join(' '),
+        parent: post.parent,
         original_created_from: post.original_created_from,
         original_created_before: post.original_created_before,
         created_at: Time.current,

backend/spec/requests/error_responses_spec.rb

@@ -1,47 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe 'error responses', type: :request do
-  describe 'manual input errors' do
-    it 'returns a stable payload for bad requests' do
-      get '/tags/name/%20/deerjikists'
-
-      expect(response).to have_http_status(:bad_request)
-      expect(json).to include(
-          'type' => 'bad_request',
-          'message' => be_present,
-          'errors' => {},
-          'base_errors' => [be_present])
-    end
-
-    it 'returns a stable field-error payload for unprocessable requests' do
-      member = create(:user, :member)
-      tag = create(:tag, :general, name: 'error_response_tag')
-      sign_in_as(member)
-
-      patch "/tags/#{ tag.id }", params: { category: 'nico' }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json).to include(
-          'type' => 'validation_error',
-          'message' => '入力内容を確認してください．',
-          'base_errors' => [])
-      expect(json.fetch('errors')).to include(
-          'category' => ['ニコタグは変更できません．'])
-    end
-  end
-
-  describe 'model validation errors' do
-    it 'returns field messages for model errors' do
-      user = create(:user)
-      sign_in_as(user)
-
-      put "/users/#{ user.id }", params: { name: 'a' * 256 }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json).to include(
-          'type' => 'validation_error',
-          'message' => '入力内容を確認してください．')
-      expect(json.fetch('errors').fetch('name')).to include(be_present)
-    end
-  end
-end

backend/spec/requests/gekanator_games_spec.rb

@@ -1,76 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe 'Gekanator games API', type: :request do
-  let!(:admin) { create_admin_user! }
-  let!(:user) { create_member_user! }
-  let!(:guessed_post) { Post.create!(title: 'guess', url: 'https://example.com/guess') }
-  let!(:correct_post) { Post.create!(title: 'correct', url: 'https://example.com/correct') }
-
-  describe 'POST /gekanator/games' do
-    it 'stores a won game' do
-      sign_in_as admin
-
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          correct_post_id: guessed_post.id,
-          answers: [{ question_id: 'tag:1', answer: 'yes' }] }
-
-      expect(response).to have_http_status(:created)
-      game = GekanatorGame.find(json['id'])
-      expect(game.user).to eq(admin)
-      expect(game.guessed_post).to eq(guessed_post)
-      expect(game.correct_post).to eq(guessed_post)
-      expect(game.won).to eq(true)
-      expect(game.question_count).to eq(1)
-      expect(game.answers).to eq([{ 'question_id' => 'tag:1', 'answer' => 'yes' }])
-    end
-
-    it 'stores a lost game with the correct post' do
-      sign_in_as admin
-
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          correct_post_id: correct_post.id,
-          question_count: 4,
-          answers: [{ question_id: 'tag:1', answer: 'no' }] }
-
-      expect(response).to have_http_status(:created)
-      game = GekanatorGame.find(json['id'])
-      expect(game.correct_post).to eq(correct_post)
-      expect(game.won).to eq(false)
-      expect(game.question_count).to eq(1)
-    end
-
-    it 'rejects a game without the correct post' do
-      sign_in_as admin
-
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          question_count: 4,
-          answers: [{ question_id: 'tag:1', answer: 'no' }] }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-    end
-
-    it 'returns unauthorized without a user' do
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          correct_post_id: guessed_post.id,
-          answers: [] }
-
-      expect(response).to have_http_status(:unauthorized)
-    end
-
-    it 'stores a game for a non-admin user' do
-      sign_in_as user
-
-      post '/gekanator/games', params: {
-          guessed_post_id: guessed_post.id,
-          correct_post_id: guessed_post.id,
-          answers: [{ question_id: 'tag:1', answer: 'yes' }] }
-
-      expect(response).to have_http_status(:created)
-      expect(GekanatorGame.find(json['id']).user).to eq(user)
-    end
-  end
-end

backend/spec/requests/gekanator_posts_spec.rb

@@ -1,33 +0,0 @@
-require 'rails_helper'
-
-
-RSpec.describe 'Gekanator posts API', type: :request do
-  describe 'GET /gekanator/posts' do
-    it 'omits deprecated tags and returns the stored similarity cosine' do
-      active_tag = Tag.create!(name: 'active tag', category: :general)
-      deprecated_tag = Tag.create!(
-        name: 'deprecated tag',
-        category: :general,
-        deprecated_at: Time.current
-      )
-      post_record = Post.create!(title: 'source', url: 'https://example.com/source')
-      target_post = Post.create!(title: 'target', url: 'https://example.com/target')
-
-      PostTag.create!(post: post_record, tag: active_tag)
-      PostTag.create!(post: post_record, tag: deprecated_tag)
-      PostTag.create!(post: target_post, tag: deprecated_tag)
-      PostSimilarity.create!(post: post_record, target_post:, cos: 0.375)
-
-      get '/gekanator/posts'
-
-      expect(response).to have_http_status(:ok)
-
-      post_json = json.fetch('posts').find { |post| post.fetch('id') == post_record.id }
-      expect(post_json.fetch('tags').map { |tag| tag.fetch('name') }).to eq(['active tag'])
-      expect(post_json.fetch('post_similarity_edges')).to contain_exactly(
-        'target_post_id' => target_post.id,
-        'cos' => 0.375
-      )
-    end
-  end
-end

backend/spec/requests/materials_spec.rb

@@ -141,21 +141,16 @@ RSpec.describe 'Materials API', type: :request do
     context 'when logged in' do
       before { sign_in_as(guest_user) }
 
-      it 'returns 422 when tag is blank' do
+      it 'returns 400 when tag is blank' do
         post '/materials', params: { tag: '   ', file: dummy_upload }
 
-        expect(response).to have_http_status(:unprocessable_entity)
-        expect(json.fetch('errors')).to include(
-            'tag' => ['タグは必須です．'])
+        expect(response).to have_http_status(:bad_request)
       end
 
-      it 'returns 422 when both file and url are blank' do
+      it 'returns 400 when both file and url are blank' do
         post '/materials', params: { tag: 'material_create_blank' }
 
-        expect(response).to have_http_status(:unprocessable_entity)
-        expect(json.fetch('errors')).to include(
-            '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．'])
+        expect(response).to have_http_status(:bad_request)
       end
 
       it 'creates a material with an attached file' do
@@ -266,26 +261,21 @@ RSpec.describe 'Materials API', type: :request do
         expect(response).to have_http_status(:not_found)
       end
 
-      it 'returns 422 when tag is blank' do
+      it 'returns 400 when tag is blank' do
         put "/materials/#{ material.id }", params: {
           tag: '   ',
           file: dummy_upload
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
-        expect(json.fetch('errors')).to include(
-            'tag' => ['タグは必須です．'])
+        expect(response).to have_http_status(:bad_request)
       end
 
-      it 'returns 422 when both file and url are blank' do
+      it 'returns 400 when both file and url are blank' do
         put "/materials/#{ material.id }", params: {
           tag: 'material_update_no_payload'
         }
 
-        expect(response).to have_http_status(:unprocessable_entity)
-        expect(json.fetch('errors')).to include(
-            '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．'])
+        expect(response).to have_http_status(:bad_request)
       end
 
       it 'updates tag, url, file, and updated_by_user' do

backend/spec/requests/nico_tags_spec.rb

@@ -3,68 +3,12 @@ require 'rails_helper'
 
 RSpec.describe 'NicoTags', type: :request do
   describe 'GET /tags/nico' do
-    it 'returns paginated tags and total count' do
-      create_list(:tag, 3, :nico)
-
-      get '/tags/nico', params: { page: 2, limit: 2 }
-
+    it 'returns tags and next_cursor when overflowing limit' do
+      create_list(:tag, 21, :nico)
+      get '/tags/nico', params: { limit: 20 }
       expect(response).to have_http_status(:ok)
-      expect(json['tags'].size).to eq(1)
-      expect(json['count']).to eq(3)
-    end
-
-    it 'filters by nico tag name, linked tag name, and link status' do
-      linked = create(:tag, :nico)
-      linked.tag_name.update!(name: 'nico:search_linked')
-      unlinked = create(:tag, :nico)
-      unlinked.tag_name.update!(name: 'nico:search_unlinked')
-      other = create(:tag, :nico)
-      other.tag_name.update!(name: 'nico:other')
-      destination = create(:tag, :general)
-      destination.tag_name.update!(name: 'destination_search')
-      NicoTagRelation.create!(nico_tag: linked, tag: destination)
-      NicoTagRelation.create!(nico_tag: other, tag: create(:tag, :general))
-
-      get '/tags/nico', params: {
-        name: 'search_',
-        linked_tag: 'destination_',
-        link_status: 'linked'
-      }
-
-      expect(response).to have_http_status(:ok)
-      expect(json['count']).to eq(1)
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([linked.id])
-
-      get '/tags/nico', params: { name: 'search_', link_status: 'unlinked' }
-
-      expect(json['count']).to eq(1)
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([unlinked.id])
-    end
-
-    it 'sorts by name and timestamps' do
-      older = create(:tag, :nico)
-      older.tag_name.update!(name: 'nico:a')
-      older.update_columns(created_at: 2.days.ago)
-      newer = create(:tag, :nico)
-      newer.tag_name.update!(name: 'nico:b')
-      newer.update_columns(created_at: 1.day.ago)
-      older_post_tag =
-        PostTag.create!(post: Post.create!(url: 'https://example.com/nico-older'), tag: older)
-      older_post_tag.update_columns(created_at: 1.hour.ago)
-      newer_post_tag =
-        PostTag.create!(post: Post.create!(url: 'https://example.com/nico-newer'), tag: newer)
-      newer_post_tag.update_columns(created_at: 2.hours.ago)
-
-      get '/tags/nico', params: { order: 'name:desc' }
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([newer.id, older.id])
-
-      get '/tags/nico', params: { order: 'created_at:asc' }
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([older.id, newer.id])
-
-      get '/tags/nico', params: { order: 'updated_at:desc' }
-      expect(json.fetch('tags').map { |tag| tag['id'] }).to eq([older.id, newer.id])
-      expect(Time.zone.parse(json.fetch('tags').first.fetch('recent_post_tag_created_at')))
-        .to be_within(1.second).of(older_post_tag.created_at)
+      expect(json['tags'].size).to eq(20)
+      expect(json['next_cursor']).to be_present
     end
   end
 
@@ -131,7 +75,7 @@ RSpec.describe 'NicoTags', type: :request do
       expect(versions.last.created_by_user_id).to eq(admin.id)
     end
 
-    it 'returns 422 when linked tag normalises to nico tag' do
+    it '400 when linked tag normalises to nico tag' do
       sign_in_as(member)
 
       other_nico = create(:tag, :nico, name: 'nico:linked_ng')
@@ -143,37 +87,7 @@ RSpec.describe 'NicoTags', type: :request do
         patch "/tags/nico/#{nico_tag.id}", params: { tags: 'linked_ng_alias' }
       }.not_to change(NicoTagVersion, :count)
 
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json.fetch('errors')).to include(
-          'tags' => ['ニコニコ・タグ同士は連携できません．'])
-    end
-
-    it 'returns the tags field error when a nico tag is specified directly' do
-      sign_in_as(member)
-
-      patch "/tags/nico/#{nico_tag.id}", params: { tags: 'nico:linked_ng' }
-
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json.fetch('errors')).to include(
-          'tags' => ['ニコニコ・タグ同士は連携できません．'])
-    end
-
-    it 'returns tag name validation errors on the tags field and rolls back created tags' do
-      sign_in_as(member)
-      TagNameSanitisationRule.create!(
-        priority: 1,
-        source_pattern: 'invalid',
-        replacement: 'valid'
-      )
-      nico_tag
-
-      expect {
-        patch "/tags/nico/#{nico_tag.id}", params: { tags: 'created_first invalid' }
-      }.not_to change(TagName, :count)
-
-      expect(response).to have_http_status(:unprocessable_entity)
-      expect(json.fetch('errors').fetch('tags')).to include(
-          a_string_including('タグ名 “invalid”:', '名前に使用できない文字が含まれてゐます．'))
+      expect(response).to have_http_status(:bad_request)
     end
   end
 end

backend/spec/requests/tag_versions_spec.rb

@@ -21,29 +21,22 @@ RSpec.describe 'TagVersions API', type: :request do
     event_type:,
     name:,
     category:,
-    deprecated_at: nil,
     aliases: [],
     parent_tags: [],
     created_by_user:,
     created_at:
   )
-    version =
-        TagVersion.create!(
-            tag: tag,
-            version_no: version_no,
-            event_type: event_type,
-            name: name,
-            category: category,
-            deprecated_at: deprecated_at,
-            aliases: Array(aliases).join(' '),
-            parent_tag_ids: Array(parent_tags).map(&:id).join(' '),
-            created_by_user: created_by_user,
-            created_at: created_at)
-
-    tag.update_columns(version_no: version_no) if tag.has_attribute?(:version_no)
-    tag.version_no = version_no if tag.respond_to?(:version_no=)
-
-    version
+    TagVersion.create!(
+      tag: tag,
+      version_no: version_no,
+      event_type: event_type,
+      name: name,
+      category: category,
+      aliases: Array(aliases).join(' '),
+      parent_tag_ids: Array(parent_tags).map(&:id).join(' '),
+      created_by_user: created_by_user,
+      created_at: created_at
+    )
   end
 
   let!(:v1) do
@@ -67,7 +60,6 @@ RSpec.describe 'TagVersions API', type: :request do
       event_type: 'update',
       name: 'new_tag_name',
       category: 'meme',
-      deprecated_at: t_v2,
       aliases: ['alias_shared', 'alias_new'],
       parent_tags: [parent_shared, parent_new],
       created_by_user: member,
@@ -136,10 +128,6 @@ RSpec.describe 'TagVersions API', type: :request do
         'current' => 'meme',
         'prev' => 'general'
       )
-      expect(latest.fetch('deprecated_at')).to eq(
-        'current' => t_v2.iso8601,
-        'prev' => nil
-      )
       expect(latest.fetch('aliases')).to include(
         { 'name' => 'alias_shared', 'type' => 'context' },
         { 'name' => 'alias_new', 'type' => 'added' },
@@ -185,10 +173,6 @@ RSpec.describe 'TagVersions API', type: :request do
         'current' => 'general',
         'prev' => nil
       )
-      expect(first.fetch('deprecated_at')).to eq(
-        'current' => nil,
-        'prev' => nil
-      )
       expect(first.fetch('aliases')).to include(
         { 'name' => 'alias_shared', 'type' => 'added' },
         { 'name' => 'alias_old', 'type' => 'added' }