素材管理 (#306) (#381)

開発環境では、**DB を壊さない前提で、migration → API → 画面 → 同期 → ZIP → 履歴**の順に見るのがよいです。今回の差分は素材管理全体に触っているので、単体でチョンチョン見るより、素材の一生を通すのが早いです。

## 0. 先に方針

**やらないこと:**

```sh id="snb3i6"
rails db:drop
rails db:reset
rails db:setup
DISABLE_DATABASE_ENVIRONMENT_CHECK=1 ...
```

これは禁止。
開発 DB に本番データを入れているなら、床板を剥がして耐震確認するようなものです。

---

## 1. migration 確認

まず現在の状態を見る。

```sh id="qsdfpt"
cd backend
RAILS_ENV=development bundle exec rails db:migrate:status
```

その後、通常 migration。

```sh id="a89fir"
RAILS_ENV=development bundle exec rails db:migrate
```

見るポイント:

```txt id="c1u57a"
materials に source_* / normalized_source_key / version_no がある
material_versions に event_type / file snapshot / source snapshot がある
material_export_items がある
material_sync_suppressions がある
material_sync_sources がある
既存 materials に material_versions version_no=1 create が backfill されている
```

確認用:

```sh id="g4vd4m"
RAILS_ENV=development bundle exec rails runner '
puts "materials=#{Material.count}"
puts "versions=#{MaterialVersion.count}"
puts "materials without versions=#{Material.left_joins(:material_versions).where(material_versions: { id: nil }).count}"
puts "sync suppressions table=#{ActiveRecord::Base.connection.table_exists?(:material_sync_suppressions)}"
'
```

ここで `materials without versions=0` になれば、backfill は通っています。

---

## 2. 既存素材一覧の画面確認

フロントを起動して `/materials` を見る。

```sh id="vl28jd"
cd frontend
npm run dev
```

見る観点:

```txt id="i2ovxw"
初期表示で素材が出る
初期表示ではグルーピングがオフ
タグなし素材も出る
カード表示でサムネまたは代替テキストが出る
一覧表示に切り替えられる
q / tag_state / media_kind / sort / direction が効く
```

ここでまず、普通の素材一覧が壊れていないことを確認します。

---

## 3. 左タグバーの確認

`/materials` を開いて左タグバーからタグを選ぶ。

見る観点:

```txt id="n6udul"
URL が tag_id=...&include_descendants=1&group_by=parent_tag になる
選択中タグが左バーで強調される
一覧上部に「選択中」の表示が出る
「タグ選択を解除」で通常表示に戻れる
解除後、tag_id / include_descendants / group_by / page が消える
子タグ・孫タグの素材も一覧に出る
親タググルーピングされる
```

特に重要なのはこれ。

```txt id="d33os0"
親タグ A を選択
  A に直接紐づく素材
  A > B に紐づく素材
  A > B > C に紐づく素材
が同じ一覧に出ること
```

---

## 4. 選択タグから素材追加

左タグからタグを選択した状態で、一覧上部の **このタグに素材を追加** を押す。

見る観点:

```txt id="qdd5uw"
素材追加画面の tag 欄に選択中タグ名が初期入力されている
file または url を指定して保存できる
保存後 return_to で元のタグ選択済み一覧に戻る
戻った一覧に追加した素材が出る
material_versions に create が 1 件できる
```

Rails console でも確認できます。

```sh id="i07rrb"
RAILS_ENV=development bundle exec rails runner '
m = Material.order(id: :desc).first
puts({ id: m.id, tag: m.tag&.name, versions: m.material_versions.count, version_no: m.version_no }.inspect)
'
```

---

## 5. グループ見出しから素材追加

親タググルーピング表示中に、各グループ見出しの **このタグに素材を追加** を押す。

見る観点:

```txt id="fpx8w4"
グループタグ名が tag 欄に初期入力される
保存後、元の一覧に戻る
追加素材がそのグループ内に出る
```

ここは今回の導線の肝です。棚の見出しから直接その棚へ素材を置けるかを見る。

---

## 6. 素材更新と履歴

既存素材の詳細または編集導線から、タグ・URL・ファイル・export path を更新する。

見る観点:

```txt id="w36i61"
更新前 snapshot が無ければ create が補われる
更新後 update version ができる
file_blob_id / file_filename / file_sha256 が material_versions に入る
export_paths_json が履歴に残る
/materials/changes または /materials/versions で履歴が見える
```

console:

```sh id="a3okhv"
RAILS_ENV=development bundle exec rails runner '
m = Material.order(updated_at: :desc).first
puts m.material_versions.order(:version_no).map { |v|
  [v.version_no, v.event_type, v.tag_name, v.file_filename, v.file_sha256, v.export_paths_hash]
}.inspect
'
```

---

## 7. サムネイル

画像素材を追加して、一覧にサムネイルが出るか確認。

動画素材があるなら、`ffmpeg` が入っている環境で backfill。

```sh id="qxm8fj"
cd backend
RAILS_ENV=development bundle exec rails materials:thumbnails:backfill
```

見る観点:

```txt id="s9a1vf"
画像は 180x180 のサムネが付く
動画はフレームからサムネが作られる
非対応ファイルは代替テキスト表示になる
ログに result が出る
```

---

## 8. ZIP export

export path がある素材を用意して、ブラウザで確認。

```txt id="aq7f7o"
/materials/download.zip?profile=legacy_drive
```

見る観点:

```txt id="h4rve5"
ZIP が落ちる
entry path が material_export_items.export_path になる
disabled な export item は入らない
ファイル実体が欠けている場合は 422 と missing_files が返る
```

---

## 9. 抑止

`/materials/suppressions` で path prefix 抑止を追加する。

見る観点:

```txt id="w80jbu"
member で作成できる
guest は forbidden / unauthorized
google_drive_path_prefix で既存素材が discard される
discard 履歴が material_versions に残る
同期時に同じ source_path 配下が再作成されない
```

---

## 10. Google Drive 同期

開発環境では、まず小さいフォルダでやるのがよいです。
いきなり本番素材集フォルダを食わせると、ログが藪になります 🌿

必要な ENV:

```sh id="kzbb7f"
GOOGLE_DRIVE_SERVICE_ACCOUNT_EMAIL=...
GOOGLE_DRIVE_PRIVATE_KEY_PATH=...
MATERIAL_SYNC_SOURCE_KIND=google_drive_path
MATERIAL_SYNC_SOURCE_FILE_ID=<folder_id>
MATERIAL_SYNC_SOURCE_NAME=dev-small-folder
MATERIAL_SYNC_SOURCE_PROFILE=legacy_drive
```

seed で source 作成、または console で作成。

```sh id="sec40c"
RAILS_ENV=development bundle exec rails db:seed
RAILS_ENV=development bundle exec rails materials:sync
```

見る観点:

```txt id="a5ltqu"
imported / updated / unchanged / suppressed / failed がログに出る
2 回目実行で unchanged が増える
tag は nil のままでも保存できる
人手で tag / url を付けた既存同期素材が、再同期で消えない
Google native file は skip される
download 後 sha256 block が効く
```

---

## 11. schema.rb は別途確認

これはテストというより merge gate です。
今回まだ怪しいので、差分に以下が混ざっていないことを確認します。

```txt id="s3k6da"
wiki_assets 削除
wiki_pages.next_asset_no 削除
素材管理と無関係な CHECK constraint 削除
素材管理と無関係な index order 消失
```

ここが残るなら、機能テストが通っても merge は止めた方がいいです。

---

## 最小テスト順

時間がないなら、この順で十分です。

```txt id="c1k2pw"
1. db:migrate
2. materials without versions = 0 を確認
3. /materials 初期表示
4. 左タグ選択 → 子孫込み表示 → グルーピング
5. タグ選択解除
6. 選択タグから素材追加 → return_to で戻る
7. グループ見出しから素材追加
8. 更新して material_versions を確認
9. ZIP export
10. 小さい Drive folder で materials:sync を 2 回
```

これで、今回の差分の主要な導線はほぼ踏めます。

Reviewed-on: #381
Co-authored-by: miteruzo <miteruzo@naver.com>
Co-committed-by: miteruzo <miteruzo@naver.com>

frontend/src/components/MaterialSidebar.tsx

@@ -1,23 +1,43 @@
-import { Fragment, useEffect, useState } from 'react'
+import { useQuery } from '@tanstack/react-query'
+import { useEffect, useRef, useState } from 'react'
+import { useLocation, useNavigate } from 'react-router-dom'
 
-import TagLink from '@/components/TagLink'
 import SidebarComponent from '@/components/layout/SidebarComponent'
-import { apiGet } from '@/lib/api'
+import TagLink from '@/components/TagLink'
+import { fetchMaterialTagTree, parseMaterialFilter } from '@/lib/materials'
+import { materialsKeys } from '@/lib/queryKeys'
+import { cn } from '@/lib/utils'
 
-import type { FC, ReactNode } from 'react'
+import type { CSSProperties, Dispatch, FC, ReactNode, SetStateAction } from 'react'
 
-import type { Tag } from '@/types'
+import type { MaterialFilter, MaterialSidebarTag, Tag } from '@/types'
 
-type TagWithDepth = Tag & {
-    hasChildren:  boolean
-    children:     TagWithDepth[] }
+const FILTERS: MaterialFilter[] = ['missing', 'present', 'any']
+const FILTER_LABELS: Record<MaterialFilter, string> = { present: '有', missing: '無', any: '全' }
+
+
+const px = (value: string): number => {
+  const parsed = Number.parseFloat (value)
+  return Number.isFinite (parsed) ? parsed : 0
+}
+
+
+const verticalChrome = (el: HTMLElement): number => {
+  const style = window.getComputedStyle (el)
+
+  return (
+      px (style.paddingTop)
+      + px (style.paddingBottom)
+      + px (style.borderTopWidth)
+      + px (style.borderBottomWidth))
+}
 
 
 const setChildrenById = (
-    tags:     TagWithDepth[],
+    tags:     MaterialSidebarTag[],
     targetId: number,
-    children: TagWithDepth[],
-): TagWithDepth[] => (
+    children: MaterialSidebarTag[],
+): MaterialSidebarTag[] => (
     tags.map (tag => {
       if (tag.id === targetId)
 	return { ...tag, children }
@@ -25,75 +45,462 @@ const setChildrenById = (
       if (tag.children.length === 0)
 	return tag
 
-      return { ...tag,
-	       children: (setChildrenById (tag.children, targetId, children)
-			  .filter (t => t.category !== 'meme' || t.hasChildren)) }
+      return { ...tag, children: setChildrenById (tag.children, targetId, children) }
     }))
 
 
-const MaterialSidebar: FC = () => {
-  const [tags, setTags] = useState<TagWithDepth[]> ([])
-  const [openTags, setOpenTags] = useState<Record<number, boolean>> ({ })
-  const [tagFetchedFlags, setTagFetchedFlags] = useState<Record<number, boolean>> ({ })
+const materialPath = (
+    tagId: number,
+    materialFilter: MaterialFilter,
+): string =>
+    `/materials?tag_id=${ tagId }&include_descendants=1&group_by=parent_tag`
+    + `&material_filter=${ materialFilter }`
 
-  useEffect (() => {
-    void (async () => {
-      setTags ((await apiGet<TagWithDepth[]> ('/tags/with-depth'))
-	       .filter (t => t.category !== 'meme' || t.hasChildren))
-    }) ()
-  }, [])
 
-  const renderTags = (ts: TagWithDepth[], nestLevel = 0): ReactNode => (
-      ts.map (t => (
-	  <Fragment key={t.id}>
-	    <li>
-	      <div className="flex">
-		<div className="flex-none w-4">
-		  {t.hasChildren && (
-		      <a
-			  href="#"
-			  onClick={async e => {
-			    e.preventDefault ()
-			    if (!(tagFetchedFlags[t.id]))
-			      {
-				try
-				{
-				  const data =
-				      await apiGet<TagWithDepth[]> (
-					  '/tags/with-depth', { params: { parent: String (t.id) } })
-				  setTags (prev => setChildrenById (prev, t.id, data))
-				  setTagFetchedFlags (prev => ({ ...prev, [t.id]: true }))
-				}
-				catch
-				{
-				  ;
-				}
-			      }
-			    setOpenTags (prev => ({ ...prev, [t.id]: !(prev[t.id]) }))
-			  }}>
-			{openTags[t.id] ? <>&minus;</> : '+'}
-		      </a>)}
-		</div>
-		<div className="flex-1 truncate">
-		  <TagLink
-		      tag={t}
-		      nestLevel={nestLevel}
-		      title={t.name}
-		      withCount={false}
-		      withWiki={false}
-		      to={`/materials?tag=${ encodeURIComponent (t.name) }`}/>
-		</div>
-	      </div>
-	    </li>
-	    {openTags[t.id] && renderTags (t.children, nestLevel + 1)}
-	  </Fragment>)))
+const sidebarTagToTag = (tag: MaterialSidebarTag): Tag => ({
+    id:             tag.id,
+    name:           tag.name,
+    category:       tag.category,
+    deprecatedAt:   tag.deprecated ? '' : null,
+    aliases:        [],
+    parents:        [],
+    postCount:      0,
+    createdAt:      '',
+    updatedAt:      '',
+    hasWiki:        false,
+    materialId:     null,
+    hasDeerjikists: false,
+    matchedAlias:   null })
 
-  return (
-      <SidebarComponent>
-	<ul>
-	  {renderTags (tags)}
-	</ul>
-      </SidebarComponent>)
+
+const tagSelectionShellClass = (selected: boolean): string =>
+    cn (selected
+	? ['rounded-md border border-sky-500 bg-sky-50 px-2 py-1 text-sky-700',
+	   'dark:border-sky-400 dark:bg-sky-950 dark:text-sky-100']
+	: 'px-2 py-1')
+
+
+const updateMaterialFilterQuery = (
+    pathname: string,
+    locationSearch: string,
+    navigate: ReturnType<typeof useNavigate>,
+    materialFilter: MaterialFilter,
+) => {
+  const qs = new URLSearchParams (locationSearch)
+  qs.set ('material_filter', materialFilter)
+  navigate (`${ pathname }${ qs.toString () ? `?${ qs.toString () }` : '' }`)
 }
 
-export default MaterialSidebar
+
+const MaterialFilterButtons: FC<{ materialFilter: MaterialFilter
+				  onChange:       (materialFilter: MaterialFilter) => void }> = (
+    { materialFilter, onChange },
+) => (
+    <div className="flex flex-wrap gap-2 justify-end md:justify-start flex-center">
+      <label className="my-auto text-sm font-bold">素材：</label>
+      {FILTERS.map (value => (
+	  <button
+	      key={value}
+	      type="button"
+	      onClick={() => onChange (value)}
+	      className={cn (
+		  'rounded-full border px-3 py-1 text-sm',
+		  (materialFilter === value
+		   ? ['border-sky-500 bg-sky-50 text-sky-700 dark:border-sky-400',
+		      'dark:bg-sky-950 dark:text-sky-100']
+		   : ['border-neutral-300 bg-white text-neutral-700 dark:border-stone-700',
+		      'dark:bg-stone-900 dark:text-stone-200']))}>
+	    {FILTER_LABELS[value]}
+	  </button>))}
+    </div>)
+
+
+const MaterialTreeNode: FC<{
+    materialFilter: MaterialFilter
+    selectedTagId:  number | null
+    nestLevel?:     number
+    onChildren:     (tagId: number, children: MaterialSidebarTag[]) => void
+    openTags:       Record<number, boolean>
+    setOpenTags:    Dispatch<SetStateAction<Record<number, boolean>>>
+    tag:            MaterialSidebarTag
+}> = ({ materialFilter, nestLevel = 0, onChildren, openTags, selectedTagId,
+	 setOpenTags, tag }) => {
+  const open = Boolean (openTags[tag.id])
+  const { data } = useQuery ({
+      queryKey: materialsKeys.tree ({ parentId: tag.id, materialFilter }),
+      queryFn:	() => fetchMaterialTagTree ({ parentId: tag.id, materialFilter }),
+      enabled:	open && tag.hasChildren && tag.children.length === 0})
+
+  useEffect (() => {
+    if (open && data && tag.children.length === 0)
+      onChildren (tag.id, data)
+  }, [data, onChildren, open, tag.children.length, tag.id])
+
+  return (
+      <>
+	<li>
+	  <div className="flex flex-center">
+	    <div className="flex-none w-4 my-auto">
+	      {tag.hasChildren && (
+		  <button
+		      type="button"
+		      onClick={() => setOpenTags (prev => ({ ...prev, [tag.id]: !prev[tag.id] }))}
+		      className="text-neutral-500 dark:text-stone-400">
+		    {open ? <>&minus;</> : '+'}
+		  </button>)}
+	    </div>
+	    <div className="min-w-0 flex-1 my-auto">
+	      <div className={cn (tagSelectionShellClass (selectedTagId === tag.id),
+				  'min-w-0 truncate')}>
+		<TagLink
+		    tag={sidebarTagToTag (tag)}
+		    nestLevel={nestLevel}
+		    title={tag.name}
+		    withCount={false}
+		    withWiki={false}
+		    to={materialPath (tag.id, materialFilter)}/>
+	      </div>
+	    </div>
+	  </div>
+	</li>
+	{open && tag.children.length > 0 && (
+	    <ul>
+	      {tag.children.map (child => (
+		  <MaterialTreeNode
+		      key={child.id}
+		      tag={child}
+		      nestLevel={nestLevel + 1}
+		      materialFilter={materialFilter}
+		      selectedTagId={selectedTagId}
+		      openTags={openTags}
+		      setOpenTags={setOpenTags}
+		      onChildren={onChildren}/>))}
+	    </ul>)}
+      </>)
+}
+
+
+const MobileMaterialTreeNode: FC<{ depth?: number
+				   availableInlineSizePx?: number | null
+				   materialFilter: MaterialFilter
+				   selectedTagId: number | null
+				   onChildren: (tagId: number, children: MaterialSidebarTag[]) =>
+						   void
+				   openTags: Record<number, boolean>
+				   setOpenTags: Dispatch<SetStateAction<Record<number, boolean>>>
+				   tag: MaterialSidebarTag }> = (
+    {
+      depth = 0,
+      availableInlineSizePx = null,
+      materialFilter,
+      onChildren,
+      openTags,
+      selectedTagId,
+      setOpenTags,
+      tag,
+    },
+) => {
+  const open = Boolean (openTags[tag.id])
+  const tagColumnRef = useRef<HTMLDivElement | null> (null)
+  const chipRef = useRef<HTMLDivElement | null> (null)
+  const buttonRef = useRef<HTMLButtonElement | null> (null)
+  const expansionSlotRef = useRef<HTMLDivElement | null> (null)
+  const expansionBorderRef = useRef<HTMLDivElement | null> (null)
+  const [tagChipInlineSizePx, setTagChipInlineSizePx] = useState<number | null> (null)
+  const [tagLinkInlineSizePx, setTagLinkInlineSizePx] = useState<number | null> (null)
+  const [childAvailableInlineSizePx, setChildAvailableInlineSizePx] = useState<number | null> (null)
+  const { data } = useQuery ({
+      queryKey: materialsKeys.tree ({ parentId: tag.id, materialFilter }),
+      queryFn:  () => fetchMaterialTagTree ({ parentId: tag.id, materialFilter }),
+      enabled:  open && tag.hasChildren && tag.children.length === 0})
+
+  useEffect (() => {
+    if (open && data && tag.children.length === 0)
+      onChildren (tag.id, data)
+  }, [data, onChildren, open, tag.children.length, tag.id])
+
+  useEffect (() => {
+    const tagColumn = tagColumnRef.current
+    const chip = chipRef.current
+    if (!(tagColumn) || !(chip))
+      return
+
+    const updateTagInlineSize = () => {
+      const buttonHeight = buttonRef.current?.offsetHeight ?? 0
+      const gap = tag.hasChildren ? px (window.getComputedStyle (tagColumn).rowGap) : 0
+      const columnHeight =
+	  availableInlineSizePx == null
+	  ? tagColumn.clientHeight
+	  : Math.min (tagColumn.clientHeight, availableInlineSizePx)
+      const nextChipInlineSize = Math.max (24, columnHeight - buttonHeight - gap)
+      const nextLinkInlineSize = Math.max (
+	  16,
+	  nextChipInlineSize - verticalChrome (chip),
+      )
+
+      setTagChipInlineSizePx (prev => prev === nextChipInlineSize ? prev : nextChipInlineSize)
+      setTagLinkInlineSizePx (prev => prev === nextLinkInlineSize ? prev : nextLinkInlineSize)
+    }
+
+    updateTagInlineSize ()
+
+    const resizeObserver = new ResizeObserver (() => {
+      updateTagInlineSize ()
+    })
+
+    resizeObserver.observe (tagColumn)
+    resizeObserver.observe (chip)
+
+    if (buttonRef.current)
+      resizeObserver.observe (buttonRef.current)
+
+    return () => {
+      resizeObserver.disconnect ()
+    }
+  }, [availableInlineSizePx, open, tag.hasChildren, tag.children.length])
+
+  useEffect (() => {
+    const expansionSlot = expansionSlotRef.current
+    const expansionBorder = expansionBorderRef.current
+    if (!(expansionSlot) || !(expansionBorder))
+      return
+
+    const updateChildInlineSize = () => {
+      const base =
+	  availableInlineSizePx == null
+	  ? expansionSlot.clientHeight
+	  : availableInlineSizePx
+      const chrome = verticalChrome (expansionSlot) + verticalChrome (expansionBorder)
+      const nextInlineSize = Math.max (24, base - chrome)
+      setChildAvailableInlineSizePx (prev => prev === nextInlineSize ? prev : nextInlineSize)
+    }
+
+    updateChildInlineSize ()
+
+    const resizeObserver = new ResizeObserver (() => {
+      updateChildInlineSize ()
+    })
+
+    resizeObserver.observe (expansionSlot)
+    resizeObserver.observe (expansionBorder)
+
+    return () => {
+      resizeObserver.disconnect ()
+    }
+  }, [availableInlineSizePx, open, tag.children.length])
+
+  return (
+      <div className="flex h-full min-h-0 max-h-full flex-row-reverse items-start gap-2
+		      overflow-hidden">
+	<div
+	    ref={tagColumnRef}
+	    className="flex h-full min-h-0 max-h-full flex-col items-center gap-1
+		       overflow-hidden">
+	  <div
+	      ref={chipRef}
+	      className={cn (
+		  tagSelectionShellClass (selectedTagId === tag.id),
+		  'box-border rounded-xl border px-3 py-2 text-sm shadow-sm',
+		  'min-h-0 overflow-hidden [max-inline-size:var(--tag-chip-inline-size)]',
+		  '[max-height:var(--tag-chip-inline-size)]',
+	      )}
+	      style={{
+		writingMode: 'vertical-rl',
+		'--tag-chip-inline-size': (
+		    tagChipInlineSizePx == null
+		    ? undefined
+		    : `${ tagChipInlineSizePx }px`),
+		'--tag-link-inline-size': (
+		    tagLinkInlineSizePx == null
+		    ? undefined
+		    : `${ tagLinkInlineSizePx }px`),
+	      } as CSSProperties}>
+	    <TagLink
+		tag={sidebarTagToTag (tag)}
+		title={tag.name}
+		withCount={false}
+		withWiki={false}
+		to={materialPath (tag.id, materialFilter)}
+		className="block overflow-hidden text-ellipsis whitespace-nowrap
+			   [max-inline-size:var(--tag-link-inline-size)]
+			   [max-height:var(--tag-link-inline-size)]"/>
+	  </div>
+	  {tag.hasChildren && (
+	      <button
+		  ref={buttonRef}
+		  type="button"
+		  onClick={() => setOpenTags (prev => ({ ...prev, [tag.id]: !prev[tag.id] }))}
+		  className="flex-none rounded-full border border-stone-300 bg-white
+			     px-2 py-0.5 text-sm text-stone-700 dark:border-stone-700
+			     dark:bg-stone-900 dark:text-stone-100">
+		{open ? <>&minus;</> : '+'}
+	      </button>)}
+	</div>
+	{open && tag.children.length > 0 && (
+	    <div
+		ref={expansionSlotRef}
+		className={cn (
+		    'h-full min-h-0 max-h-full overflow-hidden box-border',
+		    depth === 0 ? 'pt-5' : 'pt-3')}>
+	      <div
+		  ref={expansionBorderRef}
+		  className="relative max-h-full overflow-hidden rounded-2xl border border-stone-200
+			     bg-stone-100/70 py-2 pl-2 pr-2 text-stone-900
+			     dark:border-stone-700 dark:bg-stone-900/70 dark:text-stone-100">
+		<div className="flex h-full min-h-0 max-h-full flex-row-reverse items-start gap-2
+				overflow-hidden">
+		  <span
+		      aria-hidden="true"
+		      className="absolute -right-3 top-4 h-px w-3 bg-stone-300 dark:bg-stone-600"/>
+		  {tag.children.map (child => (
+		      <div
+			  key={child.id}
+			  className="relative h-full min-h-0 max-h-full overflow-hidden">
+			<MobileMaterialTreeNode
+			    tag={child}
+			    depth={depth + 1}
+			    availableInlineSizePx={childAvailableInlineSizePx}
+			    materialFilter={materialFilter}
+			    selectedTagId={selectedTagId}
+			    openTags={openTags}
+			    setOpenTags={setOpenTags}
+			    onChildren={onChildren}/>
+		      </div>))}
+		</div>
+	      </div>
+	    </div>)}
+      </div>)
+}
+
+
+const MaterialSidebar: FC = () => {
+  const location = useLocation ()
+  const navigate = useNavigate ()
+  const qs = new URLSearchParams (location.search)
+  const materialFilter = parseMaterialFilter (qs.get ('material_filter'), 'any')
+  const selectedTagId = Number (qs.get ('tag_id') ?? 0) || null
+
+  const [desktopTags, setDesktopTags] = useState<MaterialSidebarTag[]> ([])
+  const [openTags, setOpenTags] = useState<Record<number, boolean>> ({ })
+  const mobileRailRef = useRef<HTMLDivElement | null> (null)
+  const [mobileAvailableInlineSizePx, setMobileAvailableInlineSizePx] =
+      useState<number | null> (null)
+
+  const { data: rootTags = [], isLoading, isError } = useQuery ({
+      queryKey: materialsKeys.tree ({ parentId: null, materialFilter }),
+      queryFn:  () => fetchMaterialTagTree ({ parentId: null, materialFilter })})
+
+  useEffect (() => {
+    setDesktopTags (rootTags)
+  }, [rootTags])
+
+  useEffect (() => {
+    const el = mobileRailRef.current
+    if (!(el))
+      return
+
+    requestAnimationFrame (() => {
+      el.scrollLeft = el.scrollWidth
+    })
+  }, [rootTags, materialFilter])
+
+  useEffect (() => {
+    const el = mobileRailRef.current
+    if (!(el))
+      return
+
+    const updateAvailableInlineSize = () => {
+      const nextInlineSize = Math.max (24, el.clientHeight)
+      setMobileAvailableInlineSizePx (prev => prev === nextInlineSize ? prev : nextInlineSize)
+    }
+
+    updateAvailableInlineSize ()
+
+    const resizeObserver = new ResizeObserver (() => {
+      updateAvailableInlineSize ()
+    })
+
+    resizeObserver.observe (el)
+
+    return () => {
+      resizeObserver.disconnect ()
+    }
+  }, [rootTags, materialFilter])
+
+  const visibleRootTags = desktopTags.length > 0 ? desktopTags : rootTags
+
+  const setChildren = (tagId: number, children: MaterialSidebarTag[]) => {
+    setDesktopTags (prev => {
+      const base = prev.length > 0 ? prev : rootTags
+      return setChildrenById (base, tagId, children)
+    })
+  }
+
+  const handleFilterChange = (value: MaterialFilter) => {
+    setDesktopTags ([])
+    setOpenTags ({ })
+    updateMaterialFilterQuery (location.pathname, location.search, navigate, value)
+  }
+
+  const renderDesktopTree = (tags: MaterialSidebarTag[]): ReactNode => (
+      tags.map (tag => (
+	  <MaterialTreeNode
+	      key={tag.id}
+	      tag={tag}
+	      materialFilter={materialFilter}
+	      selectedTagId={selectedTagId}
+	      openTags={openTags}
+	      setOpenTags={setOpenTags}
+	      onChildren={setChildren}/>)))
+
+  return (
+      <>
+	<div className="border-b bg-stone-50 p-3 dark:border-stone-700 dark:bg-stone-950
+			dark:text-stone-100 md:hidden flex h-[25dvh] min-h-0 flex-col
+			overflow-hidden">
+	  <MaterialFilterButtons
+	      materialFilter={materialFilter}
+	      onChange={handleFilterChange}/>
+	  <div
+	      ref={mobileRailRef}
+	      className="mt-3 min-h-0 flex-1 overflow-x-auto overflow-y-hidden">
+	    <div className="flex min-w-max flex-row-reverse items-start gap-3 pb-1 h-full
+			    min-h-0 max-h-full">
+	      {visibleRootTags.map (tag => (
+		  <MobileMaterialTreeNode
+		      key={tag.id}
+		      tag={tag}
+		      availableInlineSizePx={mobileAvailableInlineSizePx}
+		      materialFilter={materialFilter}
+		      selectedTagId={selectedTagId}
+		      openTags={openTags}
+		      setOpenTags={setOpenTags}
+		      onChildren={setChildren}/>))}
+	    </div>
+	  </div>
+	</div>
+
+	<div className="hidden md:block">
+	  <SidebarComponent>
+	    <div className="space-y-4">
+	      <MaterialFilterButtons
+		  materialFilter={materialFilter}
+		  onChange={handleFilterChange}/>
+	      {isLoading && (
+		  <p className="text-sm text-neutral-500 dark:text-stone-400">読込中……</p>)}
+	      {isError && (
+		  <p className="text-sm text-red-600 dark:text-red-300">
+		    タグ一覧の取得に失敗しました．
+		  </p>)}
+	      {(!isLoading && !isError) && (
+		  <ul>
+		    {renderDesktopTree (visibleRootTags)}
+		  </ul>)}
+	    </div>
+	  </SidebarComponent>
+	</div>
+      </>)
+}
+
+
+export default MaterialSidebar