Melo/lib/library/playlist_service.dart

import 'package:flutter/foundation.dart';
import '../services/navidrome_service.dart';
import 'database.dart';

/// Koordiniert Playlisten- und Favoriten-Operationen; benachrichtigt Listener
/// nach jeder Mutation (für Feedback wie SnackBars — die Listen selbst
/// beobachten UIs direkt über die watch()-Streams von [MeloDb]).
class PlaylistService extends ChangeNotifier {
  PlaylistService(this.db, {NavidromeService? navidrome})
      : _navidrome = navidrome ?? NavidromeService();
  final MeloDb db;
  final NavidromeService _navidrome;

  Future<String> createPlaylist(String name, {String? description}) async {
    final id = await db.createPlaylist(name, description: description);
    notifyListeners();
    return id;
  }

  Future<void> deletePlaylist(String id) async {
    await db.deletePlaylist(id);
    notifyListeners();
  }

  Future<void> addSongToPlaylist(String playlistId, String songId, int position) async {
    await db.addSongToPlaylist(playlistId, songId, position);
    notifyListeners();
  }

  Future<void> removeSongFromPlaylist(String playlistId, String songId) async {
    await db.removeSongFromPlaylist(playlistId, songId);
    notifyListeners();
  }

  Future<void> reorderSong(String playlistId, String songId, int newPosition) async {
    await db.reorderPlaylistSong(playlistId, songId, newPosition);
    notifyListeners();
  }

  Future<void> reorderAll(String playlistId, List<String> orderedSongIds) async {
    await db.reorderAllPlaylistSongs(playlistId, orderedSongIds);
    notifyListeners();
  }

  Future<void> toggleFavorite(String songId) async {
    await db.toggleFavorite(songId);
    notifyListeners();
  }

  /// Lädt alle Favoriten vom Navidrome-Server und importiert sie lokal.
  /// Gibt die Anzahl geladen Favoriten zurück oder 0 wenn nicht verbunden.
  Future<int> syncFavoritesFromServer() async {
    await _navidrome.ladeGespeicherteZugangsdaten();
    if (!_navidrome.istVerbunden) return 0;

    try {
      final serverFavorites = await _navidrome.getFavorites();
      for (final song in serverFavorites) {
        // Prüfe ob Song lokal existiert, dann markiere als Favorit
        final exists = await db.songExists(song.id);
        if (exists) {
          await db.setFavorite(song.id, true);
        }
      }
      notifyListeners();
      return serverFavorites.length;
    } catch (e) {
      debugPrint('Fehler beim Laden von Server-Favoriten: $e');
      return 0;
    }
  }
}