#41

frontend/src/lib/gekanator.ts

@@ -17,11 +17,9 @@ export type GekanatorAnswerLog = {
 
 export type GekanatorQuestionKind =
     | 'tag'
-    | 'title'
-    | 'date'
-    | 'media'
     | 'source'
-    | 'structure'
+    | 'title'
+    | 'original_date'
 
 export type GekanatorQuestion = {
     id:    string
@@ -54,6 +52,19 @@ const hostOf = (post: Post): string | null => {
 }
 
 
+const originalYearOf = (post: Post): number | 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.getFullYear ()
+}
+
+
 const tagQuestionKey = ({ category, name }: { category: string; name: string }): string =>
     `${ category }:${ name }`
 
@@ -113,9 +124,11 @@ export const buildGekanatorQuestions = (posts: Post[]): GekanatorQuestion[] => {
 	  && !(tag.name.includes ('bot操作')))
       .map (tag => tagQuestionKey (tag))))
   const hosts = countBy (posts.map (hostOf).filter ((host): host is string => Boolean (host)))
-  const tagMedian = median (posts.map (post => post.tags.length))
+  const originalYears = countBy (
+      posts
+      .map (originalYearOf)
+      .filter ((year): year is number => year !== null))
   const titleLengthMedian = median (posts.map (post => post.title?.length ?? 0))
-  const currentYear = new Date ().getFullYear ()
 
   const usefulEntries = <T extends string | number> (counts: Map<T, number>) =>
       [...counts.entries ()]
@@ -144,63 +157,41 @@ export const buildGekanatorQuestions = (posts: Post[]): GekanatorQuestion[] => {
       .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
       .slice (0, 20)
       .map (([host]) => ({
-      id:   `source:${ host }`,
-      text: `${ host } の投稿を思ひ浮かべてゐる?`,
-      kind: 'source' as const,
-      test: (post: Post) => hostOf (post) === host }))
+	  id:   `source:${ host }`,
+	  text: `${ host } の投稿を思ひ浮かべてゐる?`,
+	  kind: 'source' as const,
+	  test: (post: Post) => hostOf (post) === host }))
 
-  return [
-      ...sourceQuestions,
-      {
-	  id:   'title:present',
-	  text: '題名が付いてゐる投稿?',
-	  kind: 'title',
-	  test: post => Boolean (post.title) },
+  const originalYearQuestions = usefulEntries (originalYears)
+      .filter (([, count]) => count >= 2 && count <= Math.max (2, posts.length * .7))
+      .slice (0, 20)
+      .map (([year]) => ({
+	  id:   `original-year:${ year }`,
+	  text: `オリジナルの投稿年は ${ year } 年?`,
+	  kind: 'original_date' as const,
+	  test: (post: Post) => originalYearOf (post) === year }))
+
+  const titleQuestions = [
       {
 	  id:   'title:long',
 	  text: '題名が長めの投稿?',
-	  kind: 'title',
-	  test: post => (post.title?.length ?? 0) > titleLengthMedian },
+	  kind: 'title' as const,
+	  test: (post: Post) => (post.title?.length ?? 0) > titleLengthMedian },
       {
 	  id:   'title:ascii',
 	  text: '題名に英数字が混じってゐる?',
-	  kind: 'title',
-	  test: post => /[A-Za-z0-9]/.test (post.title ?? '') },
-      {
-	  id:   'media:thumbnail',
-	  text: 'ぱっと見でサムネが付いてゐる投稿?',
-	  kind: 'media',
-	  test: post => Boolean (post.thumbnail || post.thumbnailBase) },
-      {
-	  id:   'media:video-source',
-	  text: '動画として見られる投稿?',
-	  kind: 'media',
-	  test: post => /nicovideo|youtube|youtu\.be/.test (post.url) },
-      {
-	  id:   'structure:many-tags',
-	  text: 'タグが多めに付いてゐる投稿?',
-	  kind: 'structure',
-	  test: post => post.tags.length > tagMedian },
-      {
-	  id:   'structure:no-title',
-	  text: '題名がまだ付いてゐない投稿?',
-	  kind: 'structure',
-	  test: post => !(post.title) },
-      {
-	  id:   'date:recent',
-	  text: '最近追加されたほうの投稿?',
-	  kind: 'date',
-	  test: post => new Date (post.createdAt).getFullYear () >= currentYear - 1 },
-      {
-	  id:   'date:old',
-	  text: 'むかし追加されたほうの投稿?',
-	  kind: 'date',
-	  test: post => new Date (post.createdAt).getFullYear () <= currentYear - 3 },
-      {
-	  id:   'date:original-known',
-	  text: 'オリジナルの投稿日時が分かってゐる投稿?',
-	  kind: 'date',
-	  test: post => Boolean (post.originalCreatedFrom || post.originalCreatedBefore) },
+	  kind: 'title' as const,
+	  test: (post: Post) => /[A-Za-z0-9]/.test (post.title ?? '') }]
+      .filter (question => {
+	const yes = posts.filter (post => question.test (post)).length
+	const no = posts.length - yes
+	return yes >= 2 && no >= 2 && yes <= posts.length * .7 && no <= posts.length * .7
+      })
+
+  return [
+      ...sourceQuestions,
+      ...originalYearQuestions,
+      ...titleQuestions,
       ...tagQuestions]
 }
 
@@ -208,18 +199,15 @@ export const buildGekanatorQuestions = (posts: Post[]): GekanatorQuestion[] => {
 export const saveGekanatorGame = async ({
     guessedPostId,
     correctPostId,
-    won,
     answers,
 }: {
     guessedPostId:  number
-    correctPostId:  number | null
-    won:            boolean
+    correctPostId:  number
     answers:        GekanatorAnswerLog[]
 }): Promise<{ id: number }> =>
     await apiPost ('/gekanator/games', {
 	guessed_post_id: guessedPostId,
 	correct_post_id: correctPostId,
-	won,
 	question_count: answers.length,
 	answers: answers.map (answer => ({
 	    question_id: answer.questionId,