backend/app/models/post.rb

@@ -19,7 +19,7 @@ class Post < ApplicationRecord
   has_many :gekanator_correct_games,
            class_name: 'GekanatorGame',
            foreign_key: :correct_post_id,
-           dependent: :nullify,
+           dependent: :delete_all,
            inverse_of: :correct_post
 
   has_many :parent_post_implications,

frontend/src/lib/gekanator.ts

@@ -65,6 +65,37 @@ const originalYearOf = (post: Post): number | null => {
 }
 
 
+const originalDateOf = (post: Post): Date | null => {
+  const value = post.originalCreatedFrom || post.originalCreatedBefore
+  if (!(value))
+    return null
+
+  const date = new Date (value)
+  if (Number.isNaN (date.getTime ()))
+    return null
+
+  return date
+}
+
+
+const originalMonthOf = (post: Post): number | null => {
+  const date = originalDateOf (post)
+  if (!(date))
+    return null
+
+  return date.getMonth () + 1
+}
+
+
+const originalMonthDayOf = (post: Post): string | null => {
+  const date = originalDateOf (post)
+  if (!(date))
+    return null
+
+  return `${ date.getMonth () + 1 }-${ date.getDate () }`
+}
+
+
 const tagQuestionKey = ({ category, name }: { category: string; name: string }): string =>
     `${ category }:${ name }`
 
@@ -78,6 +109,27 @@ const tagFromQuestionKey = (key: string): { category: string; name: string } =>
 const nicoTagLabel = (name: string): string => name.replace (/^nico:/, '')
 
 
+const tagQuestionText = (category: string, label: string): string => {
+  switch (category)
+  {
+  case 'deerjikist':
+    return `作者・ニジラーとして「${ label }」に関係してゐる?`
+  case 'meme':
+    return `元ネタ・ミームとして「${ label }」に関係しさう?`
+  case 'character':
+    return `「${ label }」といふキャラクターが関係してゐる?`
+  case 'material':
+    return `素材として「${ label }」に関係してゐる?`
+  case 'nico':
+    return `ニコニコに「${ label }」といふタグが付いてゐる?`
+  case 'general':
+  case 'meta':
+  default:
+    return `内容として「${ label }」に関係しさう?`
+  }
+}
+
+
 const questionableTag = (post: Post, key: string): boolean => {
   const { category, name } = tagFromQuestionKey (key)
 
@@ -128,6 +180,14 @@ export const buildGekanatorQuestions = (posts: Post[]): GekanatorQuestion[] => {
       posts
       .map (originalYearOf)
       .filter ((year): year is number => year !== null))
+  const originalMonths = countBy (
+      posts
+      .map (originalMonthOf)
+      .filter ((month): month is number => month !== null))
+  const originalMonthDays = countBy (
+      posts
+      .map (originalMonthDayOf)
+      .filter ((monthDay): monthDay is string => monthDay !== null))
   const titleLengthMedian = median (posts.map (post => post.title?.length ?? 0))
 
   const usefulEntries = <T extends string | number> (counts: Map<T, number>) =>
@@ -146,9 +206,7 @@ export const buildGekanatorQuestions = (posts: Post[]): GekanatorQuestion[] => {
 
 	return {
 	    id:   `tag:${ key }`,
-	    text: category === 'nico'
+	    text: tagQuestionText (category, label),
-		? `ニコニコに「${ label }」といふタグが付いてゐる?`
-		: `内容として「${ label }」に関係しさう?`,
 	    kind: 'tag' as const,
 	    test: (post: Post) => questionableTag (post, String (key)) }
       })
@@ -171,6 +229,28 @@ export const buildGekanatorQuestions = (posts: Post[]): GekanatorQuestion[] => {
 	  kind: 'original_date' as const,
 	  test: (post: Post) => originalYearOf (post) === year }))
 
+  const originalMonthQuestions = usefulEntries (originalMonths)
+      .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
+      .slice (0, 20)
+      .map (([month]) => ({
+	  id:   `original-month:${ month }`,
+	  text: `オリジナルの投稿月は ${ month } 月?`,
+	  kind: 'original_date' as const,
+	  test: (post: Post) => originalMonthOf (post) === month }))
+
+  const originalMonthDayQuestions = usefulEntries (originalMonthDays)
+      .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
+      .slice (0, 20)
+      .map (([monthDay]) => {
+	const [month, day] = String (monthDay).split ('-')
+
+	return {
+	    id:   `original-month-day:${ monthDay }`,
+	    text: `オリジナルの投稿日は ${ month } 月 ${ day } 日?`,
+	    kind: 'original_date' as const,
+	    test: (post: Post) => originalMonthDayOf (post) === monthDay }
+      })
+
   const titleQuestions = [
       {
 	  id:   'title:long',
@@ -191,6 +271,8 @@ export const buildGekanatorQuestions = (posts: Post[]): GekanatorQuestion[] => {
   return [
       ...sourceQuestions,
       ...originalYearQuestions,
+      ...originalMonthQuestions,
+      ...originalMonthDayQuestions,
       ...titleQuestions,
       ...tagQuestions]
 }

frontend/src/pages/GekanatorPage.tsx

@@ -18,7 +18,14 @@ import type { GekanatorAnswerLog,
 	      GekanatorQuestion } from '@/lib/gekanator'
 import type { Post } from '@/types'
 
-type Phase = 'intro' | 'question' | 'guess' | 'continue' | 'review' | 'learned'
+type Phase =
+    | 'intro'
+    | 'question'
+    | 'guess'
+    | 'continue'
+    | 'end'
+    | 'review'
+    | 'learned'
 
 type AnswerOption = {
     label:  string
@@ -687,9 +694,11 @@ const GekanatorPage: FC = () => {
       }
   }
 
-  const startReview = (correctPostId: number) => {
+  const finishGame = (correctPostId: number) => {
     const guessedPostId =
-	phase === 'continue'
+	phase === 'end' || phase === 'review'
+	  ? reviewGuessedPostId
+	  : phase === 'continue'
 	  ? lastRejectedGuessId ?? displayedGuess?.id
 	  : displayedGuess?.id ?? lastRejectedGuessId
     if (!(guessedPostId))
@@ -700,6 +709,16 @@ const GekanatorPage: FC = () => {
     setReviewCorrectPostId (correctPostId)
     setSearch ('')
     setSelectingCorrectPost (false)
+    setPhase ('end')
+  }
+
+  const startReview = () => {
+    if (reviewGuessedPostId === null || reviewCorrectPostId === null)
+      return
+
+    saveMutation.reset ()
+    setSelectingCorrectPost (false)
+    setSearch ('')
     setPhase ('review')
   }
 
@@ -805,7 +824,7 @@ const GekanatorPage: FC = () => {
 	return
       }
 
-    startReview (post.id)
+    finishGame (post.id)
   }
 
   const filteredPosts = posts
@@ -963,7 +982,7 @@ const GekanatorPage: FC = () => {
 				       hover:bg-pink-500"
 			    onClick={() => {
 			      if (displayedGuess)
-				startReview (displayedGuess.id)
+				finishGame (displayedGuess.id)
 			    }}>
 			  当たり
 			</button>
@@ -1022,6 +1041,67 @@ const GekanatorPage: FC = () => {
 		      </div>
 		    </div>)}
 
+		{phase === 'end' && (
+		    <div className="space-y-4">
+		      <div>
+			<p className="text-sm text-neutral-500">ゲーム終了</p>
+			<p className="text-xl font-bold">今回の結果を保存できます。</p>
+		      </div>
+
+		      {reviewGuessedPost && (
+			  <div className="space-y-2">
+			    <div className="font-bold">推測した投稿</div>
+			    <PostMiniCard post={reviewGuessedPost}/>
+			  </div>)}
+
+		      <div className="space-y-2">
+			<div className="font-bold">正解の投稿</div>
+			{reviewCorrectPost
+			 ? <PostMiniCard post={reviewCorrectPost}/>
+			 : <p className="text-sm text-red-600">正解投稿を選んでください。</p>}
+			<button
+			    type="button"
+			    className="rounded border border-yellow-300 px-3 py-2
+				       hover:bg-yellow-100 dark:border-red-700
+				       dark:hover:bg-red-900"
+			    onClick={() => setSelectingCorrectPost (true)}>
+			  正解投稿を変更
+			</button>
+		      </div>
+
+		      {reviewGuessedPostId !== null && reviewCorrectPostId !== null && (
+			  <p className="text-sm text-neutral-600 dark:text-neutral-300">
+			    判定: {reviewGuessedPostId === reviewCorrectPostId ? '当たり' : '違ひ'}
+			  </p>)}
+
+		      {saveMutation.isError && (
+			  <p className="text-sm text-red-600">
+			    学習ログの保存に失敗しました。もう一度試せます。
+			  </p>)}
+
+		      <div className="flex flex-wrap gap-2">
+			<button
+			    type="button"
+			    className="rounded bg-pink-600 px-4 py-2 font-bold text-white
+				       hover:bg-pink-500 disabled:opacity-50"
+			    disabled={
+			      reviewCorrectPostId === null || saveMutation.isPending || saved
+			    }
+			    onClick={saveReviewedResult}>
+			  保存
+			</button>
+			<button
+			    type="button"
+			    className="rounded border border-yellow-300 px-4 py-2
+				       hover:bg-yellow-100 dark:border-red-700
+				       dark:hover:bg-red-900"
+			    disabled={reviewCorrectPostId === null || saveMutation.isPending || saved}
+			    onClick={startReview}>
+			  質問と回答を訂正する
+			</button>
+		      </div>
+		    </div>)}
+
 		{phase === 'review' && (
 		    <div className="space-y-4">
 		      <div>
@@ -1105,7 +1185,7 @@ const GekanatorPage: FC = () => {
 			    className="rounded border border-neutral-300 px-4 py-2
 				       hover:bg-neutral-100 dark:border-neutral-700
 				       dark:hover:bg-red-900"
-			    onClick={() => setPhase ('guess')}>
+			    onClick={() => setPhase ('end')}>
 			  戻る
 			</button>
 		      </div>
@@ -1126,7 +1206,7 @@ const GekanatorPage: FC = () => {
 	    </div>
 	  </section>
 
-	  {['guess', 'continue', 'question', 'review'].includes (phase)
+	  {['guess', 'continue', 'question', 'end', 'review'].includes (phase)
 	   && selectingCorrectPost && (
 	      <section className="rounded-lg border border-yellow-300 bg-white p-4
 				  dark:border-red-800 dark:bg-red-950">