#302

backend/AGENTS.md

@@ -4,7 +4,9 @@
 
 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.
+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
 
@@ -50,14 +52,16 @@ If a command cannot be run or fails, report the exact command and failure.
 - `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.
+- `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.
+Before changing behavior, inspect the matching route, controller, model,
+service, representation, and spec.
 
 ## Ruby style
 
@@ -65,17 +69,29 @@ Before changing behavior, inspect the matching route, controller, model, service
 - Use single quotes unless interpolation or escaping makes double quotes better.
 - Do not put a space before Ruby method-call parentheses.
 - 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.
+- For multi-line Ruby hashes and keyword constructors, prefer a readable
+  vertical shape with the opening brace on its own line.
+- Put one logical field per line when the expression would otherwise
+  become dense.
 - 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`.
+- 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.
+- 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.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.
 
@@ -88,7 +104,8 @@ Before changing behavior, inspect the matching route, controller, model, service
 - 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.
+- If changing request authentication or controller before actions, add or
+  update request specs covering banned users and banned IP addresses.
 
 ## RSpec
 
@@ -99,49 +116,83 @@ Before changing behavior, inspect the matching route, controller, model, service
 - 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, especially status codes, permissions, response shape, and version conflict behavior.
+- `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, 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`.
+- 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.
+- 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.
+- 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:
+- 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`.
+- `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 and cover conflicts in request specs.
+- For optimistic concurrency paths, preserve `base_version_no`, `force`, and
+  `merge` semantics and cover conflicts in request specs.
 
 ## 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.
+- 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.
+- 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.
+- 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.
+- 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/app/controllers/theatre_programmes_controller.rb

@@ -9,6 +9,9 @@ class TheatreProgrammesController < ApplicationController
     programmes = TheatreProgramme
                  .where(theatre_id: params[:theatre_id])
                  .where('position > ?', position_gt)
+                 .includes(post: [:uploaded_user, :parents, :children,
+                                  { thumbnail_attachment: :blob },
+                                  { tags: [:deerjikists, :materials, { tag_name: :wiki_page }] }])
                  .order(position: :desc).limit(100)
                  .limit(limit)
 

backend/app/models/tag.rb

@@ -81,7 +81,7 @@ class Tag < ApplicationRecord
 
   def material_id = materials.first&.id
 
-  def has_deerjikists = deerjikists.exists?
+  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)

backend/app/services/theatre_post_selector.rb

@@ -1,7 +1,7 @@
 class TheatrePostSelector
   Candidate = Struct.new(:post, :weight, :penalty, :tags, keyword_init: true)
 
-  def initialize(theatre:)
+  def initialize theatre:
     @theatre = theatre
   end
 
@@ -20,13 +20,15 @@ class TheatrePostSelector
     candidates.last.post
   end
 
-  def weight_json(limit: 20)
+  def weight_json limit: 20
     candidates = weighted_candidates
     sorted = candidates.sort_by { |candidate| [candidate.weight, candidate.post.id] }
 
-    { tag_penalties: tag_penalty_json,
+    {
+      tag_penalties: tag_penalty_json,
       lightest_posts: post_weight_json(sorted.first(limit)),
-      heaviest_posts: post_weight_json(sorted.reverse.first(limit)) }
+      heaviest_posts: post_weight_json(sorted.reverse.first(limit))
+    }
   end
 
   private
@@ -41,7 +43,13 @@ class TheatrePostSelector
       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))
+
+        Candidate.new(
+          post:,
+          penalty:,
+          tags: post_tags,
+          weight: 1.0 / (1.0 + penalty)
+        )
       end
     end
   end
@@ -58,35 +66,59 @@ class TheatrePostSelector
 
   def tag_penalties
     @tag_penalties ||=
-        if active_user_ids.empty?
-          {}
-        else
-          TheatreSkipEventVoter
+      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
   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: TagRepr.inline(tag), penalty: }
-    }.compact.sort_by { |row| [-row[:penalty], row[:tag]['name'].to_s] }
+    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)
+  def post_weight_json candidates
     candidates.map { |candidate|
-      { post: PostRepr.base(candidate.post),
+      {
+        post: light_post_json(candidate.post),
         weight: candidate.weight,
         penalty: candidate.penalty,
-        tags: candidate.tags.map { |tag| TagRepr.inline(tag) } }
+        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
     }
   end
 end