#302

backend/app/controllers/posts_controller.rb

@@ -44,7 +44,8 @@ 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(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+        .preload(:parents, :children,
+                 tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
         .with_attached_thumbnail
 
     q = q.where('posts.url LIKE ?', "%#{ url }%") if url
@@ -95,7 +96,8 @@ class PostsController < ApplicationController
   end
 
   def random
-    post = filtered_posts.preload(tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
+    post = filtered_posts.preload(:parents, :childern,
+                                  tags: [:deerjikists, :materials, { tag_name: :wiki_page }])
                          .order('RAND()')
                          .first
     return head :not_found unless post
@@ -104,7 +106,11 @@ class PostsController < ApplicationController
   end
 
   def show
-    post = Post.includes(tags: [:deerjikists, :materials, { tag_name: :wiki_page }]).find_by(id: params[:id])
+    post = Post
+           .preload(:parents, :children)
+           .includes(:parents, :children,
+                     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)

backend/app/controllers/theatre_comments_controller.rb

@@ -1,14 +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.negative?
+    no_gt = 0 if no_gt < 0
 
     comments = TheatreComment
                .where(theatre_id: params[:theatre_id])
                .where('no > ?', no_gt)
                .order(no: :desc)
+               .limit(limit)
 
-    render json: comments.as_json(include: { user: { only: [:id, :name] } })
+    render json: comments.map {
+      _1.as_json(include: { user: { only: [:id, :name] } })
+          .merge(content: _1.discarded? ? nil : _1.content, deleted: _1.discarded?)
+    }
   end
 
   def create
@@ -29,4 +36,18 @@ 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

backend/app/controllers/theatre_programmes_controller.rb

@@ -0,0 +1,17 @@
+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

backend/app/controllers/theatres_controller.rb

@@ -43,11 +43,14 @@ class TheatresController < ApplicationController
     return head :not_found unless theatre
     return head :forbidden if theatre.host_user != current_user
 
-    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)
+    ApplicationRecord.transaction do
+      post = Post.where("url LIKE '%nicovideo.jp%'")
+             .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

backend/app/models/tag.rb

@@ -81,7 +81,7 @@ class Tag < ApplicationRecord
 
   def material_id = materials.first&.id
 
-  def has_deerjikists = deerjikists.present?
+  def has_deerjikists = 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/models/theatre.rb

@@ -7,6 +7,8 @@ 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'

backend/app/models/theatre_programme.rb

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

backend/config/routes.rb

@@ -87,7 +87,8 @@ Rails.application.routes.draw do
       patch :next_post
     end
 
-    resources :comments, controller: :theatre_comments, only: [:index, :create]
+    resources :comments, controller: :theatre_comments, only: [:index, :create, :destroy]
+    resources :programmes, controller: :theatre_programmes, only: [:index]
   end
 
   resources :materials, only: [:index, :show, :create, :update, :destroy]

backend/db/migrate/20260514221900_create_theatre_programmes.rb

@@ -0,0 +1,10 @@
+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/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_05_07_213300) do
+ActiveRecord::Schema[8.0].define(version: 2026_05_14_221900) 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
@@ -283,6 +283,15 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) 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
@@ -290,6 +299,7 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) 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"
@@ -464,6 +474,8 @@ ActiveRecord::Schema[8.0].define(version: 2026_05_07_213300) 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"

frontend/src/App.tsx

@@ -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/>}/>
+	  <Route path="/theatres/:id" element={<TheatreDetailPage user={user}/>}/>
 	  <Route path="/materials" element={<MaterialBasePage/>}>
 	    <Route index element={<MaterialListPage/>}/>
 	    <Route path="new" element={<MaterialNewPage/>}/>
@@ -158,4 +158,4 @@ const App: FC = () => {
       </>)
 }
 
-export default App
+export default App

frontend/src/components/TopNav.tsx

@@ -55,12 +55,6 @@ 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' },
@@ -71,6 +65,8 @@ 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 },
@@ -267,7 +263,7 @@ 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-24">
+			  className="z-10 h-full flex items-center px-3 font-bold w-28">
 			<h2>{item.name}</h2>
 		      </motion.div>
 		      {item.subMenu

frontend/src/pages/theatres/TheatreDetailPage.tsx

@@ -6,20 +6,24 @@ 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, apiPatch, apiPost, apiPut, isApiError } from '@/lib/api'
+import { apiGet, apiDelete, apiPatch, apiPost, apiPut, isApiError } from '@/lib/api'
 import { fetchPost } from '@/lib/posts'
 import { dateString } from '@/lib/utils'
 
-import type { FC } from 'react'
+import type { FC, User } from 'react'
 
 import type { NiconicoMetadata,
 	      NiconicoViewerHandle,
 	      Post,
 	      Theatre,
-	      TheatreComment } from '@/types'
+	      TheatreComment,
+	      TheatreProgramme } from '@/types'
 
 type TheatreInfo = {
     hostFlg:        boolean
@@ -34,9 +38,36 @@ const INITIAL_THEATRE_INFO =
       watchingUsers: [] as { id: number; name: string }[] } as const
 
 
-const TheatreDetailPage: FC = () => {
+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 { id } = useParams ()
 
+  const dialogue = useDialogue ()
+
   const commentsRef = useRef<HTMLDivElement> (null)
   const embedRef = useRef<NiconicoViewerHandle> (null)
   const loadingRef = useRef (false)
@@ -52,6 +83,7 @@ const TheatreDetailPage: FC = () => {
   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 (() => {
@@ -118,7 +150,7 @@ const TheatreDetailPage: FC = () => {
       {
 	const newComments = await apiGet<TheatreComment[]> (
 	    `/theatres/${ id }/comments`,
-	    { params: { no_gt: lastCommentNoRef.current } })
+	    { params: { no_gt: lastCommentNoRef.current, limit: '20' } })
 
 	if (!(cancelled) && newComments.length > 0)
 	  {
@@ -214,10 +246,24 @@ const TheatreDetailPage: FC = () => {
       }
     }) ()
 
+    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
     }
-  }, [theatreInfo.postId])
+  }, [id, theatreInfo.postId])
 
   const syncPlayback = (meta: NiconicoMetadata) => {
     if (!(theatreInfo.postStartedAt))
@@ -233,12 +279,30 @@ const TheatreDetailPage: FC = () => {
       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'
@@ -270,6 +334,22 @@ const TheatreDetailPage: FC = () => {
 		  </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>
@@ -306,18 +386,36 @@ const TheatreDetailPage: FC = () => {
 		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">
-		    <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
+		      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>))}
 	    </div>
 	  </form>
@@ -345,4 +443,5 @@ const TheatreDetailPage: FC = () => {
       </div>)
 }
 
+
 export default TheatreDetailPage

frontend/src/types.ts

@@ -210,11 +210,24 @@ export type Theatre = {
     createdAt:      string
     updatedAt:      string }
 
-export type TheatreComment = {
-    theatreId:  number,
-    no:         number,
-    user:       { id: number, name: string } | null
-    content:    string
+export type TheatreComment =
+    | { theatreId:  number
+	no:         number
+	deteled:    false
+	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 = {