refactor(playlist): G.68 — extract runPlaylistSaveMeta + 3 hooks (song search / mutations / star+rating) (#635)

Four-cut cluster. 572 → 471 LOC (−101). Each handler on the page
collapses to a one-line delegate; pure code move otherwise.

runPlaylistSaveMeta — the meta save flow (updatePlaylistMeta then
optional uploadPlaylistCoverArt + getPlaylist refresh + cover toast,
or coverRemoved → null, then metaSaved toast + closes the modal).
Takes the deps separately from the opts object so the call-site
just passes through the modal's payload.

usePlaylistSongSearch — searchOpen + searchQuery driven debounced
search against subsonic. Owns the 350 ms timeout, the filter-out
of songs already in the playlist, and the searching state. Returns
{ searchResults, setSearchResults, searching } so addSong on the
page can still drop a just-added song out of the result list.

usePlaylistSongMutations — addSong / removeSong. removeSong is
trivial (filter + setSongs + savePlaylist with prevCount).
addSong preserves the .main-content scrollTop save / requestAnimationFrame
restore trick + drops the song out of both suggestions and search
results + fires the add toast with playlist name interpolation.

usePlaylistStarRating — handleRate (local override + playerStore
userRatingOverride + setRating API) + handleToggleStar (e.stopPropagation,
local set + playerStore starredOverride + star/unstar API). Reads
starredOverrides / setStarredOverride from playerStore directly so
the page doesn't have to thread them through.

PlaylistDetail drops these direct imports (now consumed in the
hooks/utility): updatePlaylistMeta, uploadPlaylistCoverArt, search,
setRating, star, unstar, showToast, useRef. Pure code move.

src/hooks/usePlaylistSongMutations.ts

@@ -0,0 +1,47 @@
+import type React from 'react';
+import type { TFunction } from 'i18next';
+import type { SubsonicPlaylist, SubsonicSong } from '../api/subsonicTypes';
+import { showToast } from '../utils/toast';
+
+export interface PlaylistSongMutationsDeps {
+  songs: SubsonicSong[];
+  setSongs: React.Dispatch<React.SetStateAction<SubsonicSong[]>>;
+  savePlaylist: (updatedSongs: SubsonicSong[], prevCount?: number) => Promise<void>;
+  setSuggestions: React.Dispatch<React.SetStateAction<SubsonicSong[]>>;
+  setSearchResults: React.Dispatch<React.SetStateAction<SubsonicSong[]>>;
+  playlist: SubsonicPlaylist | null;
+  t: TFunction;
+}
+
+export interface PlaylistSongMutations {
+  removeSong: (idx: number) => void;
+  addSong: (song: SubsonicSong) => void;
+}
+
+export function usePlaylistSongMutations(deps: PlaylistSongMutationsDeps): PlaylistSongMutations {
+  const { songs, setSongs, savePlaylist, setSuggestions, setSearchResults, playlist, t } = deps;
+
+  const removeSong = (idx: number) => {
+    const prevCount = songs.length;
+    const next = songs.filter((_, i) => i !== idx);
+    setSongs(next);
+    savePlaylist(next, prevCount);
+  };
+
+  const addSong = (song: SubsonicSong) => {
+    if (songs.some(s => s.id === song.id)) return;
+    const scrollHost = document.querySelector('.main-content') as HTMLElement | null;
+    const savedScroll = scrollHost?.scrollTop ?? 0;
+    const next = [...songs, song];
+    setSongs(next);
+    savePlaylist(next);
+    setSuggestions(prev => prev.filter(s => s.id !== song.id));
+    setSearchResults(prev => prev.filter(s => s.id !== song.id));
+    if (scrollHost) {
+      requestAnimationFrame(() => { scrollHost.scrollTop = savedScroll; });
+    }
+    showToast(t('playlists.addSuccess', { count: 1, playlist: playlist?.name }));
+  };
+
+  return { removeSong, addSong };
+}

src/hooks/usePlaylistSongSearch.ts

@@ -0,0 +1,37 @@
+import { useEffect, useRef, useState } from 'react';
+import type React from 'react';
+import { search } from '../api/subsonicSearch';
+import type { SubsonicSong } from '../api/subsonicTypes';
+
+export interface PlaylistSongSearchResult {
+  searchResults: SubsonicSong[];
+  setSearchResults: React.Dispatch<React.SetStateAction<SubsonicSong[]>>;
+  searching: boolean;
+}
+
+export function usePlaylistSongSearch(
+  songs: SubsonicSong[],
+  searchOpen: boolean,
+  searchQuery: string,
+): PlaylistSongSearchResult {
+  const [searchResults, setSearchResults] = useState<SubsonicSong[]>([]);
+  const [searching, setSearching] = useState(false);
+  const searchDebounce = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  useEffect(() => {
+    if (!searchOpen || !searchQuery.trim()) { setSearchResults([]); return; }
+    if (searchDebounce.current) clearTimeout(searchDebounce.current);
+    searchDebounce.current = setTimeout(async () => {
+      setSearching(true);
+      try {
+        const res = await search(searchQuery, { songCount: 20, artistCount: 0, albumCount: 0 });
+        const existingIds = new Set(songs.map(s => s.id));
+        setSearchResults(res.songs.filter(s => !existingIds.has(s.id)));
+      } catch {}
+      setSearching(false);
+    }, 350);
+    return () => { if (searchDebounce.current) clearTimeout(searchDebounce.current); };
+  }, [searchQuery, searchOpen, songs]);
+
+  return { searchResults, setSearchResults, searching };
+}

src/hooks/usePlaylistStarRating.ts

@@ -0,0 +1,42 @@
+import React from 'react';
+import { setRating, star, unstar } from '../api/subsonicStarRating';
+import type { SubsonicSong } from '../api/subsonicTypes';
+import { usePlayerStore } from '../store/playerStore';
+
+export interface PlaylistStarRatingDeps {
+  ratings: Record<string, number>;
+  setRatings: React.Dispatch<React.SetStateAction<Record<string, number>>>;
+  starredSongs: Set<string>;
+  setStarredSongs: React.Dispatch<React.SetStateAction<Set<string>>>;
+}
+
+export interface PlaylistStarRatingActions {
+  handleRate: (songId: string, rating: number) => void;
+  handleToggleStar: (song: SubsonicSong, e: React.MouseEvent) => void;
+}
+
+export function usePlaylistStarRating(deps: PlaylistStarRatingDeps): PlaylistStarRatingActions {
+  const { setRatings, starredSongs, setStarredSongs } = deps;
+  const starredOverrides = usePlayerStore(s => s.starredOverrides);
+  const setStarredOverride = usePlayerStore(s => s.setStarredOverride);
+
+  const handleRate = (songId: string, rating: number) => {
+    setRatings(prev => ({ ...prev, [songId]: rating }));
+    usePlayerStore.getState().setUserRatingOverride(songId, rating);
+    setRating(songId, rating).catch(() => {});
+  };
+
+  const handleToggleStar = (song: SubsonicSong, e: React.MouseEvent) => {
+    e.stopPropagation();
+    const isStarred = song.id in starredOverrides ? starredOverrides[song.id] : starredSongs.has(song.id);
+    setStarredSongs(prev => {
+      const next = new Set(prev);
+      isStarred ? next.delete(song.id) : next.add(song.id);
+      return next;
+    });
+    setStarredOverride(song.id, !isStarred);
+    (isStarred ? unstar(song.id, 'song') : star(song.id, 'song')).catch(() => {});
+  };
+
+  return { handleRate, handleToggleStar };
+}

src/pages/PlaylistDetail.tsx

@@ -1,10 +1,8 @@
-import { getPlaylist, updatePlaylist, updatePlaylistMeta, uploadPlaylistCoverArt } from '../api/subsonicPlaylists';
-import { setRating, star, unstar } from '../api/subsonicStarRating';
-import { search } from '../api/subsonicSearch';
+import { getPlaylist, updatePlaylist } from '../api/subsonicPlaylists';
 import { filterSongsToActiveLibrary } from '../api/subsonicLibrary';
 import type { SubsonicPlaylist, SubsonicSong } from '../api/subsonicTypes';
 import { songToTrack } from '../utils/songToTrack';
-import React, { useEffect, useState, useRef, useCallback, useMemo } from 'react';
+import React, { useEffect, useState, useCallback, useMemo } from 'react';
 import { useParams, useNavigate, useLocation } from 'react-router-dom';
 import { ChevronDown, ChevronLeft, ChevronRight, Play, ListPlus, Trash2, Search, X, Loader2, Plus, GripVertical, Star, RefreshCw, Shuffle, Heart, HardDriveDownload, Check, Pencil, Globe, Lock, Camera, Download, FileUp, RotateCcw, Sparkles, Square, AudioLines } from 'lucide-react';
 import { useTracklistColumns, type ColDef } from '../utils/useTracklistColumns';
@@ -22,7 +20,6 @@ import { useOrbitSongRowBehavior } from '../hooks/useOrbitSongRowBehavior';
 import { useZipDownloadStore } from '../store/zipDownloadStore';
 import { useDragDrop } from '../contexts/DragDropContext';
 import { useTranslation } from 'react-i18next';
-import { showToast } from '../utils/toast';
 import StarRating from '../components/StarRating';
 import {
   formatDuration,
@@ -43,12 +40,16 @@ import PlaylistTracklist from '../components/playlist/PlaylistTracklist';
 import PlaylistFilterToolbar from '../components/playlist/PlaylistFilterToolbar';
 import { getDisplayedSongs, type PlaylistSortKey, type PlaylistSortDir } from '../utils/playlistDisplayedSongs';
 import { runPlaylistZipDownload } from '../utils/runPlaylistZipDownload';
+import { runPlaylistSaveMeta } from '../utils/runPlaylistSaveMeta';
 import { playPlaylistAll, shufflePlaylistAll, enqueuePlaylistAll } from '../utils/playlistBulkPlayActions';
 import { startPlaylistRowDrag } from '../utils/startPlaylistRowDrag';
 import { runPlaylistReorderDrop } from '../utils/runPlaylistReorderDrop';
 import { usePlaylistCovers } from '../hooks/usePlaylistCovers';
 import { usePlaylistSelection } from '../hooks/usePlaylistSelection';
 import { usePlaylistSuggestions } from '../hooks/usePlaylistSuggestions';
+import { usePlaylistSongSearch } from '../hooks/usePlaylistSongSearch';
+import { usePlaylistSongMutations } from '../hooks/usePlaylistSongMutations';
+import { usePlaylistStarRating } from '../hooks/usePlaylistStarRating';
 
 // ── Column configuration ──────────────────────────────────────────────────────
 const PL_COLUMNS: readonly ColDef[] = [
@@ -172,11 +173,10 @@ export default function PlaylistDetail() {
   // Song search
   const [searchOpen, setSearchOpen] = useState(false);
   const [searchQuery, setSearchQuery] = useState('');
-  const [searchResults, setSearchResults] = useState<SubsonicSong[]>([]);
-  const [searching, setSearching] = useState(false);
-  const searchDebounce = useRef<ReturnType<typeof setTimeout> | null>(null);
   const [selectedSearchIds, setSelectedSearchIds] = useState<Set<string>>(new Set());
   const [searchPlPickerOpen, setSearchPlPickerOpen] = useState(false);
+  const { searchResults, setSearchResults, searching } =
+    usePlaylistSongSearch(songs, searchOpen, searchQuery);
 
   // Suggestions
   const { suggestions, setSuggestions, loadingSuggestions, loadSuggestions } =
@@ -235,26 +235,10 @@ export default function PlaylistDetail() {
     coverFile: File | null; coverRemoved: boolean;
   }) => {
     if (!id || !playlist) return;
-    await updatePlaylistMeta(id, opts.name.trim() || playlist.name, opts.comment, opts.isPublic);
-    setPlaylist(p => p
-      ? { ...p, name: opts.name.trim() || p.name, comment: opts.comment, public: opts.isPublic }
-      : p
+    await runPlaylistSaveMeta(
+      { id, playlist, t, setPlaylist, setCustomCoverId, setEditingMeta },
+      opts,
     );
-    if (opts.coverFile) {
-      try {
-        await uploadPlaylistCoverArt(id, opts.coverFile);
-        const { playlist: refreshed } = await getPlaylist(id);
-        setPlaylist(prev => prev ? { ...prev, coverArt: refreshed.coverArt } : prev);
-        if (refreshed.coverArt) setCustomCoverId(refreshed.coverArt);
-        showToast(t('playlists.coverUpdated'));
-      } catch (err) {
-        showToast(err instanceof Error ? err.message : t('playlists.coverUpdated'), 3000, 'error');
-      }
-    } else if (opts.coverRemoved) {
-      setCustomCoverId(null);
-    }
-    showToast(t('playlists.metaSaved'));
-    setEditingMeta(false);
   };
 
   // ── ZIP Download ──────────────────────────────────────────────
@@ -275,28 +259,9 @@ export default function PlaylistDetail() {
   };
 
   // ── Remove ────────────────────────────────────────────────────
-  const removeSong = (idx: number) => {
-    const prevCount = songs.length;
-    const next = songs.filter((_, i) => i !== idx);
-    setSongs(next);
-    savePlaylist(next, prevCount);
-  };
-
-  // ── Add ───────────────────────────────────────────────────────
-  const addSong = (song: SubsonicSong) => {
-    if (songs.some(s => s.id === song.id)) return;
-    const scrollHost = document.querySelector('.main-content') as HTMLElement | null;
-    const savedScroll = scrollHost?.scrollTop ?? 0;
-    const next = [...songs, song];
-    setSongs(next);
-    savePlaylist(next);
-    setSuggestions(prev => prev.filter(s => s.id !== song.id));
-    setSearchResults(prev => prev.filter(s => s.id !== song.id));
-    if (scrollHost) {
-      requestAnimationFrame(() => { scrollHost.scrollTop = savedScroll; });
-    }
-    showToast(t('playlists.addSuccess', { count: 1, playlist: playlist?.name }));
-  };
+  const { removeSong, addSong } = usePlaylistSongMutations({
+    songs, setSongs, savePlaylist, setSuggestions, setSearchResults, playlist, t,
+  });
 
   // ── Preview (30s mid-song sample via Rust audio engine) ────────
   // Pause/resume of the main player + timer + cancel-on-supersede are all
@@ -320,39 +285,9 @@ export default function PlaylistDetail() {
   }, []);
 
   // ── Rating / Star ─────────────────────────────────────────────
-  const handleRate = (songId: string, rating: number) => {
-    setRatings(prev => ({ ...prev, [songId]: rating }));
-    usePlayerStore.getState().setUserRatingOverride(songId, rating);
-    setRating(songId, rating).catch(() => {});
-  };
-
-  const handleToggleStar = (song: SubsonicSong, e: React.MouseEvent) => {
-    e.stopPropagation();
-    const isStarred = song.id in starredOverrides ? starredOverrides[song.id] : starredSongs.has(song.id);
-    setStarredSongs(prev => {
-      const next = new Set(prev);
-      isStarred ? next.delete(song.id) : next.add(song.id);
-      return next;
-    });
-    setStarredOverride(song.id, !isStarred);
-    (isStarred ? unstar(song.id, 'song') : star(song.id, 'song')).catch(() => {});
-  };
-
-  // ── Search ────────────────────────────────────────────────────
-  useEffect(() => {
-    if (!searchOpen || !searchQuery.trim()) { setSearchResults([]); return; }
-    if (searchDebounce.current) clearTimeout(searchDebounce.current);
-    searchDebounce.current = setTimeout(async () => {
-      setSearching(true);
-      try {
-        const res = await search(searchQuery, { songCount: 20, artistCount: 0, albumCount: 0 });
-        const existingIds = new Set(songs.map(s => s.id));
-        setSearchResults(res.songs.filter(s => !existingIds.has(s.id)));
-      } catch {}
-      setSearching(false);
-    }, 350);
-    return () => { if (searchDebounce.current) clearTimeout(searchDebounce.current); };
-  }, [searchQuery, searchOpen, songs]);
+  const { handleRate, handleToggleStar } = usePlaylistStarRating({
+    ratings, setRatings, starredSongs, setStarredSongs,
+  });
 
   // ── psy-drop DnD reordering ───────────────────────────────────
   useEffect(() => {

src/utils/runPlaylistSaveMeta.ts

@@ -0,0 +1,46 @@
+import type { TFunction } from 'i18next';
+import { getPlaylist, updatePlaylistMeta, uploadPlaylistCoverArt } from '../api/subsonicPlaylists';
+import type { SubsonicPlaylist } from '../api/subsonicTypes';
+import { showToast } from './toast';
+
+export interface RunPlaylistSaveMetaDeps {
+  id: string;
+  playlist: SubsonicPlaylist;
+  t: TFunction;
+  setPlaylist: (updater: (p: SubsonicPlaylist | null) => SubsonicPlaylist | null) => void;
+  setCustomCoverId: (id: string | null) => void;
+  setEditingMeta: (v: boolean) => void;
+}
+
+export async function runPlaylistSaveMeta(
+  deps: RunPlaylistSaveMetaDeps,
+  opts: {
+    name: string;
+    comment: string;
+    isPublic: boolean;
+    coverFile: File | null;
+    coverRemoved: boolean;
+  },
+): Promise<void> {
+  const { id, playlist, t, setPlaylist, setCustomCoverId, setEditingMeta } = deps;
+  await updatePlaylistMeta(id, opts.name.trim() || playlist.name, opts.comment, opts.isPublic);
+  setPlaylist(p => p
+    ? { ...p, name: opts.name.trim() || p.name, comment: opts.comment, public: opts.isPublic }
+    : p
+  );
+  if (opts.coverFile) {
+    try {
+      await uploadPlaylistCoverArt(id, opts.coverFile);
+      const { playlist: refreshed } = await getPlaylist(id);
+      setPlaylist(prev => prev ? { ...prev, coverArt: refreshed.coverArt } : prev);
+      if (refreshed.coverArt) setCustomCoverId(refreshed.coverArt);
+      showToast(t('playlists.coverUpdated'));
+    } catch (err) {
+      showToast(err instanceof Error ? err.message : t('playlists.coverUpdated'), 3000, 'error');
+    }
+  } else if (opts.coverRemoved) {
+    setCustomCoverId(null);
+  }
+  showToast(t('playlists.metaSaved'));
+  setEditingMeta(false);
+}