#90

2026-05-26 05:52:09 +09:00
30 changed files with 304 additions and 286 deletions
@@ -1,4 +1,7 @@
 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!
@@ -25,6 +28,42 @@ class ApplicationController < ActionController::API
    end
  end

+  def render_bad_request message = 'リクエストが不正です．', field: nil, code: :bad_request
+    render_error(:bad_request, message, field:, code:)
+  end
+
+  def render_unprocessable_entity message = '入力を確認してください．', field: nil, code: :invalid
+    render_error(:unprocessable_entity, message, field:, code:)
+  end
+
+  def render_error status, message, field: nil, code: status
+    error = { code: code.to_s, message: }
+    error[:field] = field.to_s if field.present?
+
+    render json: { errors: [error] }, status:
+  end
+
+  def render_model_errors record, status: :unprocessable_entity
+    errors =
+        record.errors.map do |error|
+          { code: error.type.to_s,
+            field: error.attribute.to_s,
+            message: error.full_message }
+        end
+
+    errors = [{ code: 'invalid', message: '入力を確認してください．' }] if errors.empty?
+
+    render json: { errors: }, status:
+  end
+
+  def render_record_invalid error
+    render_model_errors(error.record)
+  end
+
+  def render_record_not_unique _error = nil
+    render_unprocessable_entity('既に存在してゐます．', code: :taken)
+  end
+
  def reject_banned_ip_address!
    ip_address = IpAddress.find_by(ip_address: IPAddr.new(request.remote_ip).hton)
    return unless ip_address&.banned?
@@ -37,4 +76,28 @@ class ApplicationController < ActionController::API

    head :forbidden
  end
+
+  def render_validation_error record = nil, fields: { }, base: []
+    errors = { }
+
+    if record
+      record.errors.messages.each do |attr, messages|
+        errors[attr] ||= []
+        errors[attr].concat(messages)
+      end
+    end
+
+    fields.each do |attr, messages|
+      errors[attr] ||= []
+      errors[attr].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: :unprocessable_entity
+  end
 end
@@ -2,7 +2,8 @@ class DeerjikistsController < ApplicationController
  def show
    platform = params[:platform].to_s.strip
    code = params[:code].to_s.strip
-    return head :bad_request if platform.blank? || code.blank?
+    return render_bad_request('platform は必須です．', field: :platform) if platform.blank?
+    return render_bad_request('code は必須です．', field: :code) if code.blank?

    deerjikist = Deerjikist
                 .joins(:tag)
@@ -22,7 +23,9 @@ class DeerjikistsController < ApplicationController
    platform = params[:platform].to_s.strip
    code = params[:code].to_s.strip
    tag_id = params[:tag_id].to_i
-    return head :bad_request if platform.blank? || code.blank? || tag_id <= 0
+    return render_bad_request('platform は必須です．', field: :platform) if platform.blank?
+    return render_bad_request('code は必須です．', field: :code) if code.blank?
+    return render_bad_request('tag_id が不正です．', field: :tag_id) if tag_id <= 0

    deerjikist = Deerjikist.find_or_initialize_by(platform:, code:).tap do |d|
      d.tag_id = tag_id
@@ -38,7 +41,8 @@ class DeerjikistsController < ApplicationController

    platform = params[:platform].to_s.strip
    code = params[:code].to_s.strip
-    return head :bad_request if platform.blank? || code.blank?
+    return render_bad_request('platform は必須です．', field: :platform) if platform.blank?
+    return render_bad_request('code は必須です．', field: :code) if code.blank?

    Deerjikist.find([platform, code]).destroy!

@@ -40,7 +40,8 @@ class MaterialsController < ApplicationController
    tag_name_raw = params[:tag].to_s.strip
    file = params[:file]
    url = params[:url].to_s.strip.presence
-    return head :bad_request if tag_name_raw.blank? || (file.blank? && url.blank?)
+    return render_bad_request('タグは必須です．', field: :tag) if tag_name_raw.blank?
+    return render_bad_request('ファイルまたは URL は必須です．') if file.blank? && url.blank?

    tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
    tag = tag_name.tag
@@ -54,7 +55,7 @@ class MaterialsController < ApplicationController
    if material.save
      render json: MaterialRepr.base(material, host: request.base_url), status: :created
    else
-      render json: { errors: material.errors.full_messages }, status: :unprocessable_entity
+      render_model_errors(material)
    end
  end

@@ -68,7 +69,8 @@ class MaterialsController < ApplicationController
    tag_name_raw = params[:tag].to_s.strip
    file = params[:file]
    url = params[:url].to_s.strip.presence
-    return head :bad_request if tag_name_raw.blank? || (file.blank? && url.blank?)
+    return render_bad_request('タグは必須です．', field: :tag) if tag_name_raw.blank?
+    return render_bad_request('ファイルまたは URL は必須です．') if file.blank? && url.blank?

    tag_name = TagName.find_undiscard_or_create_by!(name: tag_name_raw)
    tag = tag_name.tag
@@ -84,7 +86,7 @@ class MaterialsController < ApplicationController
    if material.save
      render json: MaterialRepr.base(material, host: request.base_url)
    else
-      render json: { errors: material.errors.full_messages }, status: :unprocessable_entity
+      render_model_errors(material)
    end
  end

@@ -30,12 +30,14 @@ class NicoTagsController < ApplicationController
    id = params[:id].to_i

    tag = Tag.find(id)
-    return head :bad_request unless tag.nico?
+    return render_bad_request('ニコニコ・タグを指定してください．', field: :id) unless tag.nico?

    linked_tag_names = params[:tags].to_s.split
    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? }
+    if linked_tags.any? { |t| t.nico? }
+      return render_bad_request('ニコニコ・タグ同士は連携できません．', field: :tags)
+    end

    ApplicationRecord.transaction do
      TagVersioning.record_tag_snapshots!(linked_tags, created_by_user: current_user)
@@ -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(:parents, :children,
-                 tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+        .preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
        .with_attached_thumbnail

    q = q.where('posts.url LIKE ?', "%#{ url }%") if url
@@ -96,8 +95,7 @@ class PostsController < ApplicationController
  end

  def random
-    post = filtered_posts.preload(:parents, :childern,
-                                  tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+    post = filtered_posts.preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
                         .order('RAND()')
                         .first
    return head :not_found unless post
@@ -106,11 +104,7 @@ class PostsController < ApplicationController
  end

  def show
-    post = Post
-           .preload(:parents, :children)
-           .includes(:parents, :children,
-                     tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
-           .find_by(id: params[:id])
+    post = Post.includes(tags: [:deerjikists, :materials, { tag_name: :wiki_page }]).find_by(id: params[:id])
    return head :not_found unless post

    render json: PostRepr.base(post, current_user)
@@ -154,11 +148,11 @@ class PostsController < ApplicationController
    post.reload
    render json: PostRepr.base(post), status: :created
  rescue Tag::NicoTagNormalisationError
-    head :bad_request
+    render_bad_request('ニコニコ・タグは直接指定できません．', field: :tags)
  rescue ArgumentError => e
-    render json: { errors: [e.message] }, status: :unprocessable_entity
+    render_unprocessable_entity(e.message)
  rescue ActiveRecord::RecordInvalid => e
-    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_entity
+    render_model_errors(e.record)
  end

  def viewed
@@ -181,10 +175,10 @@ class PostsController < ApplicationController

    force = bool?(:force)
    merge = bool?(:merge)
-    return head :bad_request if force && 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 head :bad_request if !(force) && !(base_version_no)
+    return render_bad_request('base_version_no は必須です．', field: :base_version_no) if !(force) && !(base_version_no)

    title = params[:title].presence
    tag_names = params[:tags].to_s.split
@@ -244,11 +238,11 @@ class PostsController < ApplicationController
    json['tags'] = build_tag_tree_for(post.tags)
    render json:, status: :ok
  rescue Tag::NicoTagNormalisationError
-    head :bad_request
+    render_bad_request('ニコニコ・タグは直接指定できません．', field: :tags)
  rescue ArgumentError => e
-    render json: { errors: [e.message] }, status: :unprocessable_entity
+    render_validation_error(fields: { parent_post_ids: [e.message] })
  rescue ActiveRecord::RecordInvalid => e
-    render json: { errors: e.record.errors.full_messages }, status: :unprocessable_entity
+    render_validation_error(e.record)
  end

  def changes
@@ -422,7 +416,7 @@ class PostsController < ApplicationController

  def sync_parent_posts! post, parent_post_ids
    if parent_post_ids.include?(post.id)
-      post.errors.add(:base, '自分自身を親投稿にはできません．')
+      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

@@ -4,7 +4,7 @@ class PreviewController < ApplicationController
    return head :unauthorized unless current_user

    url = params[:url]
-    return head :bad_request unless url.present?
+    return render_bad_request('URL は必須です．', field: :url) 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 json: { error: e.message }, status: :bad_request
+    render_bad_request(e.message, field: :url)
  end

  def thumbnail
@@ -25,7 +25,7 @@ class PreviewController < ApplicationController
    return head :unauthorized unless current_user

    url = params[:url]
-    return head :bad_request if url.blank?
+    return render_bad_request('URL は必須です．', field: :url) if url.blank?

    unless url.start_with?(/http(s)?:\/\//)
      url = 'http://' + url
@@ -40,7 +40,8 @@ class PreviewController < ApplicationController
      File.delete(path) rescue nil
      send_file image.path, type: 'image/png', disposition: 'inline'
    else
-      render json: { error: 'Failed to generate thumbnail' }, status: :internal_server_error
+      render_error(:internal_server_error, 'サムネールを生成できませんでした．',
+                   code: :thumbnail_generation_failed)
    end
  end
 end
@@ -5,11 +5,12 @@ class TagChildrenController < ApplicationController

    parent_id = params[:parent_id]
    child_id = params[:child_id]
-    return head :bad_request if parent_id.blank? || child_id.blank?
+    return render_bad_request('parent_id は必須です．', field: :parent_id) if parent_id.blank?
+    return render_bad_request('child_id は必須です．', field: :child_id) if child_id.blank?

    parent = Tag.find(parent_id)
    child = Tag.find(child_id)
-    return head :bad_request if parent.nico? || child.nico?
+    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?

    ApplicationRecord.transaction do
      TagVersioning.ensure_snapshot!(child, created_by_user: current_user)
@@ -27,11 +28,12 @@ class TagChildrenController < ApplicationController

    parent_id = params[:parent_id]
    child_id = params[:child_id]
-    return head :bad_request if parent_id.blank? || child_id.blank?
+    return render_bad_request('parent_id は必須です．', field: :parent_id) if parent_id.blank?
+    return render_bad_request('child_id は必須です．', field: :child_id) if child_id.blank?

    parent = Tag.find(parent_id)
    child = Tag.find(child_id)
-    return head :bad_request if parent.nico? || child.nico?
+    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?

    ApplicationRecord.transaction do
      TagVersioning.ensure_snapshot!(child, created_by_user: current_user)
@@ -168,7 +168,7 @@ class TagsController < ApplicationController

  def show_by_name
    name = params[:name].to_s.strip
-    return head :bad_request if name.blank?
+    return render_bad_request('name は必須です．', field: :name) if name.blank?

    tag = Tag.joins(:tag_name)
             .includes(:tag_name, :materials, tag_name: :wiki_page)
@@ -192,7 +192,7 @@ class TagsController < ApplicationController

  def deerjikists_by_name
    name = params[:name].to_s.strip
-    return head :bad_request if name.blank?
+    return render_bad_request('name は必須です．', field: :name) if name.blank?

    tag = Tag.joins(:tag_name)
             .includes(:tag_name, tag_name: :wiki_page)
@@ -228,7 +228,7 @@ class TagsController < ApplicationController

  def materials_by_name
    name = params[:name].to_s.strip
-    return head :bad_request if name.blank?
+    return render_bad_request('name は必須です．', field: :name) if name.blank?

    tag = Tag.joins(:tag_name)
             .includes(:tag_name, :materials, tag_name: :wiki_page)
@@ -247,17 +247,16 @@ class TagsController < ApplicationController

    name = params[:name].to_s.strip
    category = params[:category].to_s.strip
-    return head :unprocessable_entity if name.blank? || category.blank?
+    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?

    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
+      return render_unprocessable_entity('システム・タグの名称は変更できません．', field: :name)
    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
+      return render_unprocessable_entity('ニコタグは変更できません．', field: :category)
    end

    alias_names = params[:aliases].to_s.split.uniq
@@ -302,8 +301,7 @@ class TagsController < ApplicationController
    tag = Tag.find(params[:id])

    if tag.nico? || (category.present? && category == 'nico')
-      return render json: { error: 'ニコタグは変更できません．' },
-                    status: :unprocessable_entity
+      return render_unprocessable_entity('ニコタグは変更できません．', field: :category)
    end

    ApplicationRecord.transaction do
@@ -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 head :unprocessable_entity if content.blank?
+    return render_unprocessable_entity('本文は必須です．', field: :content) if content.blank?

    theatre = Theatre.find_by(id: params[:theatre_id])
    return head :not_found unless theatre
@@ -36,18 +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
-
-    comment.discard!
-
-    head :no_content
-  end
 end
@@ -1,17 +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)
-                 .order(position: :desc).limit(100)
-                 .limit(limit)
-
-    render json: programmes.as_json(include: { post: PostRepr::BASE })
-  end
-end
@@ -43,14 +43,11 @@ class TheatresController < ApplicationController
    return head :not_found unless theatre
    return head :forbidden if theatre.host_user != current_user

-    ApplicationRecord.transaction do
    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)
-      position = (theatre.programmes.maximum(:position) || 0) + 1
-      theatre.programmes.create!(position:, post:)
-    end

    head :no_content
  end
@@ -42,12 +42,12 @@ class UsersController < ApplicationController
    return head :unauthorized if user&.id != params[:id].to_i

    name = params[:name]
-    return head :bad_request if name.blank?
+    return render_bad_request('名前は必須です．', field: :name) if name.blank?

    if user.update(name:)
      render json: user.slice(:id, :name, :inheritance_code, :role), status: :ok
    else
-      render json: user.errors, status: :unprocessable_entity
+      render_model_errors(user)
    end
  end

@@ -46,7 +46,7 @@ class WikiPagesController < ApplicationController

  def diff
    id = params[:id]
-    return head :bad_request if id.blank?
+    return render_bad_request('id は必須です．', field: :id) if id.blank?

    from = params[:from].presence
    to = params[:to].presence
@@ -56,7 +56,7 @@ class WikiPagesController < ApplicationController
    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 head :unprocessable_entity
+      return render_unprocessable_entity('差分を表示できない版です．')
    end

    diffs = Diff::LCS.sdiff(from_rev&.body&.lines || [], to_rev.body.lines)
@@ -89,7 +89,8 @@ class WikiPagesController < ApplicationController
    body = params[:body].to_s
    message = params[:message].presence

-    return head :unprocessable_entity if title.blank? || body.blank?
+    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?

    tag_name = TagName.find_undiscard_or_create_by!(name: title)

@@ -101,8 +102,10 @@ class WikiPagesController < ApplicationController
            message:)

    render json: WikiPageRepr.base(page), status: :created
-  rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotUnique
-    head :unprocessable_entity
+  rescue ActiveRecord::RecordInvalid => e
+    render_model_errors(e.record)
+  rescue ActiveRecord::RecordNotUnique
+    render_record_not_unique
  end

  def update
@@ -112,7 +115,8 @@ class WikiPagesController < ApplicationController
    title = params[:title]&.strip
    body = params[:body].to_s

-    return head :unprocessable_entity if title.blank? || body.blank?
+    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?

    page = WikiPage.find(params[:id])
    base_revision_id = params[:base_revision_id].presence
@@ -81,7 +81,7 @@ class Tag < ApplicationRecord

  def material_id = materials.first&.id

-  def has_deerjikists = deerjikists.exists?
+  def has_deerjikists = deerjikists.present?

  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)
@@ -7,8 +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'
-
  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'
@@ -1,6 +0,0 @@
-class TheatreProgramme < ApplicationRecord
-  self.primary_key = :theatre_id, :position
-
-  belongs_to :theatre
-  belongs_to :post
-end
@@ -87,8 +87,7 @@ Rails.application.routes.draw do
      patch :next_post
    end

-    resources :comments, controller: :theatre_comments, only: [:index, :create, :destroy]
-    resources :programmes, controller: :theatre_programmes, only: [:index]
+    resources :comments, controller: :theatre_comments, only: [:index, :create]
  end

  resources :materials, only: [:index, :show, :create, :update, :destroy]
@@ -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
@@ -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_05_14_221900) do
+ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) 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
@@ -283,15 +283,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_14_221900) 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_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
@@ -299,7 +290,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_14_221900) 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"
@@ -474,8 +464,6 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_14_221900) 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_watching_users", "theatres"
  add_foreign_key "theatre_watching_users", "users"
  add_foreign_key "theatres", "posts", column: "current_post_id"
@@ -0,0 +1,47 @@
+require 'rails_helper'
+
+RSpec.describe 'error responses', type: :request do
+  describe 'manual input errors' do
+    it 'returns a stable errors array for bad requests' do
+      user = create(:user)
+      sign_in_as(user)
+
+      put "/users/#{ user.id }", params: { name: '   ' }
+
+      expect(response).to have_http_status(:bad_request)
+      expect(json.fetch('errors')).to contain_exactly(
+          include('code' => 'bad_request',
+                  'field' => 'name',
+                  'message' => be_present))
+    end
+
+    it 'returns a stable errors array 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.fetch('errors')).to contain_exactly(
+          include('code' => 'invalid',
+                  'field' => 'category',
+                  'message' => be_present))
+    end
+  end
+
+  describe 'model validation errors' do
+    it 'returns field, code, and message 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.fetch('errors')).to include(
+          include('code' => 'too_long',
+                  'field' => 'name',
+                  'message' => be_present))
+    end
+  end
+end
@@ -63,7 +63,7 @@ const RouteTransitionWrapper = ({ user, setUser }: {
 	  <Route path="/tags/:id/deerjikists" element={<DeerjikistDetailPage/>}/>
 	  <Route path="/tags/nico" element={<NicoTagListPage user={user}/>}/>
 	  <Route path="/tags/changes" element={<TagHistoryPage/>}/>
-	  <Route path="/theatres/:id" element={<TheatreDetailPage user={user}/>}/>
+	  <Route path="/theatres/:id" element={<TheatreDetailPage/>}/>
 	  <Route path="/materials" element={<MaterialBasePage/>}>
 	    <Route index element={<MaterialListPage/>}/>
 	    <Route path="new" element={<MaterialNewPage/>}/>
@@ -2,17 +2,23 @@ import { useEffect, useState } from 'react'

 import PostFormTagsArea from '@/components/PostFormTagsArea'
 import PostOriginalCreatedTimeField from '@/components/PostOriginalCreatedTimeField'
+import FieldError from '@/components/common/FieldError'
 import Label from '@/components/common/Label'
 import { useDialogue } from '@/components/dialogues/DialogueProvider'
 import { Button } from '@/components/ui/button'
 import { toast } from '@/components/ui/use-toast'
 import { isApiError } from '@/lib/api'
+import { extractValidationError } from '@/lib/apiErrors'
 import { updatePost } from '@/lib/posts'

 import type { FC, FormEvent } from 'react'

+import type { FieldErrors } from '@/lib/apiErrors'
 import type { Post, Tag } from '@/types'

+type PostFormField =
+    'parentPostId' | 'tags' | 'originalCreatedFrom' | 'originalCreatedBefore'
+

 const tagsToStr = (tags: Tag[]): string => {
  const result: Tag[] = []
@@ -34,7 +40,9 @@ type Props = { post:    Post


 const PostEditForm: FC<Props> = ({ post, onSave }) => {
+  const [baseErrors, setBaseErrors] = useState<string[]> ([])
  const [disabled, setDisabled] = useState (false)
+  const [fieldErrors, setFieldErrors] = useState<FieldErrors> ({ })
  const [originalCreatedBefore, setOriginalCreatedBefore] =
      useState<string | null> (post.originalCreatedBefore)
  const [originalCreatedFrom, setOriginalCreatedFrom] =
@@ -47,6 +55,9 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
  const dialogue = useDialogue ()

  const update = async (...args: Parameters<typeof updatePost>) => {
+    setFieldErrors ({ })
+    setBaseErrors ([])
+
    try
    {
      const data = await updatePost (...args)
@@ -67,10 +78,21 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {

      if (response?.status !== 409)
 	{
+	  const validationError = extractValidationError (e)
+
+	  if (validationError)
+	    {
+	      setFieldErrors (validationError.fieldErrors)
+	      setBaseErrors (validationError.baseErrors)
 	      toast ({ description: '更新はできなかったよ……' })
 	      return
 	    }

+	  toast ({ title: '失敗……', description: '入力を確認してください．' })
+
+	  return
+	}
+
      const action = await dialogue.choice ({
 	  title: '競合が発生しました．',
 	  description: (
@@ -142,13 +164,15 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 	      value={parentPostIds}
 	      onChange={e => setParentPostIds (e.target.value)}
 	      className="w-full border p-2 rounded"/>
+	  <FieldError messages={fieldErrors.url}/>
 	</div>

 	{/* タグ */}
 	<PostFormTagsArea
 	    disabled={disabled}
 	    tags={tags}
-	    setTags={setTags}/>
+	    setTags={setTags}
+	    errors={fieldErrors.tags}/>

 	{/* オリジナルの作成日時 */}
 	<PostOriginalCreatedTimeField
@@ -156,7 +180,9 @@ const PostEditForm: FC<Props> = ({ post, onSave }) => {
 	    originalCreatedFrom={originalCreatedFrom}
 	    setOriginalCreatedFrom={setOriginalCreatedFrom}
 	    originalCreatedBefore={originalCreatedBefore}
-	    setOriginalCreatedBefore={setOriginalCreatedBefore}/>
+	    setOriginalCreatedBefore={setOriginalCreatedBefore}
+	    fromErrors={fieldErrors.originalCreatedFrom}
+	    beforeErrors={fieldErrors.originalCreatedBefore}/>

 	{/* 送信 */}
 	<Button
@@ -3,6 +3,7 @@
 import { useRef, useState } from 'react'

 import TagSearchBox from '@/components/TagSearchBox'
+import FieldError from '@/components/common/FieldError'
 import Label from '@/components/common/Label'
 import TextArea from '@/components/common/TextArea'
 import { apiGet } from '@/lib/api'
@@ -33,10 +34,11 @@ const replaceToken = (value: string, start: number, end: number, text: string) =

 type Props = Omit<ComponentPropsWithoutRef<'textarea'>, 'value' | 'onChange' | 'onBlur'> & {
    tags:     string
-    setTags:  (tags: string) => void }
+    setTags:  (tags: string) => void
+    errors?:  string[] }


-const PostFormTagsArea: FC<Props> = ({ tags, setTags, ...rest }) => {
+const PostFormTagsArea: FC<Props> = ({ tags, setTags, errors, ...rest }) => {
  const ref = useRef<HTMLTextAreaElement> (null)

  const [bounds, setBounds] = useState<{ start: number; end: number }> ({ start: 0, end: 0 })
@@ -96,6 +98,7 @@ const PostFormTagsArea: FC<Props> = ({ tags, setTags, ...rest }) => {
 			     : [] as Tag[]}
 		activeIndex={-1}
 		onSelect={handleTagSelect}/>)}
+	<FieldError messages={errors}/>
      </div>)
 }

@@ -9,7 +9,9 @@ type Props = {
    originalCreatedFrom:      string | null
    setOriginalCreatedFrom:   (x: string | null) => void
    originalCreatedBefore:    string | null
-    setOriginalCreatedBefore: (x: string | null) => void }
+    setOriginalCreatedBefore: (x: string | null) => void
+    fromErrors?:              string[]
+    beforeErrors?:            string[] }


 const PostOriginalCreatedTimeField: FC<Props> = ({ disabled,
@@ -19,6 +21,7 @@ const PostOriginalCreatedTimeField: FC<Props> = ({ disabled,
 		   setOriginalCreatedBefore }) => (
    <div>
      <Label>オリジナルの作成日時</Label>
+
      <div className="my-1 flex">
 	<div className="w-80">
 	  <DateTimeField
@@ -51,6 +54,8 @@ const PostOriginalCreatedTimeField: FC<Props> = ({ disabled,
 	  </Button>
 	</div>
      </div>
+      <FieldError messages={fromErrors}/>
+
      <div className="my-1 flex">
 	<div className="w-80">
 	  <DateTimeField
@@ -71,6 +76,7 @@ const PostOriginalCreatedTimeField: FC<Props> = ({ disabled,
 	  </Button>
 	</div>
      </div>
+      <FieldError messages={beforeErrors}/>
    </div>)

 export default PostOriginalCreatedTimeField
@@ -55,6 +55,12 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
 	  { name: '追加', to: '/materials/new' },
 	  { name: '全体履歴', to: '/materials/changes', visible: false },
 	  { name: 'ヘルプ', to: '/wiki/ヘルプ:素材集' }] },
+      { name: '上映会', to: '/theatres/1', base: '/theatres', subMenu: [
+	  { name: <>第&thinsp;1&thinsp;会場</>, to: '/theatres/1' },
+	  { name: 'CyTube', to: '//cytube.mm428.net/r/deernijika' },
+	  { name: <>ニジカ放送局第&thinsp;1&thinsp;チャンネル</>,
+	    to: '//www.youtube.com/watch?v=DCU3hL4Uu6A' },
+	  { name: 'ヘルプ', to: '/wiki/ヘルプ:上映会' }] },
      { name: 'Wiki', to: '/wiki/ヘルプ:ホーム', base: '/wiki', subMenu: [
 	  { name: '検索', to: '/wiki' },
 	  { name: '新規', to: '/wiki/new' },
@@ -65,8 +71,6 @@ export const menuOutline = ({ tag, wikiId, user, pathName }: {
 	    visible: wikiPageFlg },
 	  { name: '履歴', to: `/wiki/changes?id=${ wikiId }`, visible: wikiPageFlg },
 	  { name: '編輯', to: `/wiki/${ wikiId || wikiTitle }/edit`, visible: wikiPageFlg }] },
-      { name: 'おたのしみ', visible: false, subMenu: [
-	  { name: '上映会 (β)', to: '/theatres/1' }] },
      { name: 'ユーザ', to: '/users/settings', visible: false, subMenu: [
 	  { name: '一覧', to: '/users', visible: false },
 	  { name: 'お前', to: `/users/${ user?.id }`, visible: false },
@@ -263,7 +267,7 @@ const TopNav: FC<Props> = ({ user }) => {
 			       : { initial: { x: 40, y: -40, opacity: 0 },
 				   animate: { x: 0, y: 0, opacity: 1 },
 				   exit: { x: 40, y: -40, opacity: 0 } })}
-			  className="z-10 h-full flex items-center px-3 font-bold w-28">
+			  className="z-10 h-full flex items-center px-3 font-bold w-24">
 			<h2>{item.name}</h2>
 		      </motion.div>
 		      {item.subMenu
@@ -0,0 +1,17 @@
+import type { FC } from 'react'
+
+type Props = { messages?: string[] }
+
+
+export const FieldError: FC<Props> = ({ messages }: Props) => {
+  if (!(messages?.length))
+    return null
+
+  return (
+      <ul className="mt-1 space-y-1 text-red-600 dark:text-red-400">
+	{messages.map ((message, i) => <li key={i}>{message}</li>)}
+      </ul>)
+}
+
+
+export default FieldError
@@ -0,0 +1,30 @@
+import toCamel from 'camelcase-keys'
+
+import { isApiError } from '@/lib/api'
+
+export type FieldErrors = Partial<Record<string, string[]>>
+
+export type ValidationError = { message:      string
+				fieldErrors:  FieldErrors
+				baseErrors:   string[] }
+
+type RawValidationError = { type?:        string
+			    message?:     string
+			    errors?:      Record<string, string[]>
+			    baseErrors?:  string[] }
+
+
+export const extractValidationError = (err: unknown) => {
+  if (!(isApiError (err)) || err.response?.status !== 422)
+    return null
+
+  const data = toCamel ((err.response.data ?? { }) as Record<string, unknown>,
+			{ deep: true }) as RawValidationError
+
+  if (data.type !== 'validation_error' && !(data.errors))
+    return null
+
+  return { message: data.message ?? '入力内容を確認してください．',
+	   fieldErrors: (data.errors ?? { }) as FieldErrors,
+	   baseErrors: data.baseErrors ?? [] }
+}
@@ -3,7 +3,6 @@ import { motion } from 'framer-motion'
 import { useEffect, useRef, useState } from 'react'
 import { Helmet } from 'react-helmet-async'
 import { useParams } from 'react-router-dom'
-
 import PostEditForm from '@/components/PostEditForm'
 import PostEmbed from '@/components/PostEmbed'
 import PostList from '@/components/PostList'
@@ -6,24 +6,20 @@ import ErrorScreen from '@/components/ErrorScreen'
 import PostEmbed from '@/components/PostEmbed'
 import PrefetchLink from '@/components/PrefetchLink'
 import TagDetailSidebar from '@/components/TagDetailSidebar'
-import SectionTitle from '@/components/common/SectionTitle'
-import { useDialogue } from '@/components/dialogues/DialogueProvider'
-import { Button } from '@/components/ui/button'
 import MainArea from '@/components/layout/MainArea'
 import SidebarComponent from '@/components/layout/SidebarComponent'
 import { SITE_TITLE } from '@/config'
-import { apiGet, apiDelete, apiPatch, apiPost, apiPut, isApiError } from '@/lib/api'
+import { apiGet, apiPatch, apiPost, apiPut, isApiError } from '@/lib/api'
 import { fetchPost } from '@/lib/posts'
 import { dateString } from '@/lib/utils'

-import type { FC, User } from 'react'
+import type { FC } from 'react'

 import type { NiconicoMetadata,
 	      NiconicoViewerHandle,
 	      Post,
 	      Theatre,
-	      TheatreComment,
-	      TheatreProgramme } from '@/types'
+	      TheatreComment } from '@/types'

 type TheatreInfo = {
    hostFlg:        boolean
@@ -38,36 +34,9 @@ const INITIAL_THEATRE_INFO =
      watchingUsers: [] as { id: number; name: string }[] } as const


-const commentBox: ReactNode[] = (comment: TheatreComment) =>
-    [(
-	<div key={`${ comment.no }-content`} className="w-full">
-	  {comment.deleted
-	   ? (
-	      <span className="text-sm font-bold">
-		削除されました．
-	      </span>)
-	   : comment.content}
-	</div>),
-     (
-	<div key={`${ comment.no }-user`} className="w-full text-sm text-right">
-	  by {comment.user
-	      ? (comment.user.name || `名もなきニジラー（#${ comment.user.id }）`)
-	      : '運営'}
-	</div>),
-     (
-	<div key={`${ comment.no }-createdAt`} className="w-full text-sm text-right">
-	  {dateString (comment.createdAt)}
-	</div>)]
-
-
-type Props = { user: User }
-
-
-const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
+const TheatreDetailPage: FC = () => {
  const { id } = useParams ()

-  const dialogue = useDialogue ()
-
  const commentsRef = useRef<HTMLDivElement> (null)
  const embedRef = useRef<NiconicoViewerHandle> (null)
  const loadingRef = useRef (false)
@@ -83,7 +52,6 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
  const [theatre, setTheatre] = useState<Theatre | null> (null)
  const [theatreInfo, setTheatreInfo] = useState<TheatreInfo> (INITIAL_THEATRE_INFO)
  const [post, setPost] = useState<Post | null> (null)
-  const [programmes, setProgrammes] = useState<TheatreProgramme[]> ([])
  const [videoLength, setVideoLength] = useState (0)

  useEffect (() => {
@@ -150,7 +118,7 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
      {
 	const newComments = await apiGet<TheatreComment[]> (
 	    `/theatres/${ id }/comments`,
-	    { params: { no_gt: lastCommentNoRef.current, limit: '20' } })
+	    { params: { no_gt: lastCommentNoRef.current } })

 	if (!(cancelled) && newComments.length > 0)
 	  {
@@ -246,24 +214,10 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
      }
    }) ()

-    void (async () => {
-      try
-      {
-	const data = await apiGet<TheatreProgramme[]> (
-	    `/theatres/${ id }/programmes`, { params: { limit: '100' } })
-	if (!(cancelled))
-	  setProgrammes (data)
-      }
-      catch (e)
-      {
-	console.error (e)
-      }
-    }) ()
-
    return () => {
      cancelled = true
    }
-  }, [id, theatreInfo.postId])
+  }, [theatreInfo.postId])

  const syncPlayback = (meta: NiconicoMetadata) => {
    if (!(theatreInfo.postStartedAt))
@@ -279,30 +233,12 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
      embedRef.current?.seek (targetTime)
  }

-  const handleDelete = async (commentNo: number) => {
-    try
-    {
-      await apiDelete (`/theatres/${ id }/comments/${ commentNo }`)
-      setComments (prev => {
-	const rtn = [...prev]
-	const idx = rtn.findIndex (x => x.no === commentNo)
-	rtn[idx] = { ...rtn[idx], deleted: true }
-	return rtn
-      })
-    }
-    catch
-    {
-      ;
-    }
-  }
-
  if (status >= 400)
    return <ErrorScreen status={status}/>

  return (
      <div className="md:flex md:flex-1 overflow-y-auto md:overflow-y-hidden">
 	<Helmet>
-	  <meta name="robots" content="noindex"/>
 	  {theatre && (
 	      <title>
 		{'上映会場'
@@ -334,22 +270,6 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 		  </PrefetchLink>
 		</div>
 	      </>) : 'Loading...'}
-
-	  <div>
-	    <SectionTitle>
-	      上映履歴
-	    </SectionTitle>
-
-	    <div>
-	      {programmes.map ((programme, i) => (
-		  <div key={i}>
-		    <PrefetchLink to={`/posts/${ programme.post.id }`}>
-		      {programme.post.title}
-		    </PrefetchLink>
-		    （{dateString (programme.createdAt)}）
-		  </div>))}
-	    </div>
-	  </div>
 	</MainArea>

 	<SidebarComponent>
@@ -386,36 +306,18 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
 		className="overflow-x-hidden overflow-y-scroll text-wrap w-full
 			   h-[32vh] md:h-[64vh] border rounded">
 	      {comments.map (comment => (
-		  <div
-		      key={comment.no}
-		      className="p-2 group relative rounded py-1 hover:bg-gray-100
-				 dark:hover:bg-gray-800">
-		    {(user && comment.user?.id === user.id && !(comment.deleted)) && (
-			<button
-			    type="button"
-			    className="absolute left-1 top-1 hidden rounded text-md text-red-600
-				       hover:bg-red-100 group-hover:inline-block
-				       dark:text-red-300 dark:hover:bg-red-950"
-			    aria-label="コメントを削除"
-			    onClick={async e => {
-			      e.stopPropagation ()
-
-			      if (!(await dialogue.confirm ({
-				  title: 'このコメントを削除しますか?',
-				  description: (
-				      <div className="border border-black dark:border-white rounded
-						      my-3 p-2 w-64">
-					{commentBox (comment)}
-				      </div>),
-				  confirmText: '削除',
-				  variant: 'danger' })))
-				return
-
-			      await handleDelete (comment.no)
-			    }}>
-			  &times;
-			</button>)}
-		    {commentBox (comment)}
+		  <div key={comment.no} className="p-2">
+		    <div className="w-full">
+		      {comment.content}
+		    </div>
+		    <div className="w-full text-sm text-right">
+		      by {comment.user
+			  ? (comment.user.name || `名もなきニジラー（#${ comment.user.id }）`)
+			  : '運営'}
+		    </div>
+		    <div className="w-full text-sm text-right">
+		      {dateString (comment.createdAt)}
+		    </div>
 		  </div>))}
 	    </div>
 	  </form>
@@ -443,5 +345,4 @@ const TheatreDetailPage: FC<Props> = ({ user }: Props) => {
      </div>)
 }

-
 export default TheatreDetailPage
@@ -210,25 +210,12 @@ export type Theatre = {
    createdAt:      string
    updatedAt:      string }

-export type TheatreComment =
-    | { theatreId:  number
-	no:         number
-	deteled:    false
+export type TheatreComment = {
+    theatreId:  number,
+    no:         number,
    user:       { id: number, name: string } | null
    content:    string
    createdAt:  string }
-    | { theatreId:  number
-	no:         number
-	deleted:    true
-	user:       { id: number, name: string } | null
-	content     null,
-	createdAt:  string }
-
-export type TheatreProgramme = {
-    theatreId:  number
-    position:   number
-    post:       Post
-    createdAt:  string }

 export type User = {
    id:               number