// lib/repositories/playlist_repository.dart
import 'dart:math';
import '../database/song_database.dart';
import '../models/playlist.dart';
import '../services/audio_service.dart';

class PlaylistRepository {
  final SongDatabase _db = SongDatabase();

  String _generateId() {
    const chars = 'abcdefghijklmnopqrstuvwxyz0123456789';
    final random = Random();
    return String.fromCharCodes(
      Iterable.generate(
          16, (_) => chars.codeUnitAt(random.nextInt(chars.length))),
    );
  }

  // ════════════════════════════════════════════════════════════
  // 歌单操作
  // ════════════════════════════════════════════════════════════

  Future<List<Playlist>> getAllPlaylists() async {
    final data = await _db.getAllPlaylists();
    return data.map((e) => Playlist.fromJson(e)).toList();
  }

  Future<Playlist?> getPlaylist(String id) async {
    final data = await _db.getPlaylist(id);
    if (data == null) return null;
    return Playlist.fromJson(data);
  }

  Future<Playlist> createPlaylist(String name) async {
    final playlist = Playlist(id: _generateId(), name: name);
    await _db.insertPlaylist(playlist.toJson());
    return playlist;
  }

  Future<void> updatePlaylistName(String id, String newName) async {
    await _db.updatePlaylist(id, {
      'name': newName,
      'updated_at': DateTime.now().millisecondsSinceEpoch,
    });
  }

  // ⭐ 新增：更新播放模式
  Future<void> updatePlaylistPlayMode(String id, PlayMode playMode) async {
    await _db.updatePlaylist(id, {
      // ⭐ 修改前：_playModeToString
      // 'play_mode': _playModeToString(playMode),

      // ⭐ 修改后：用公开静态方法
      'play_mode': Playlist.playModeToString(playMode),
      'updated_at': DateTime.now().millisecondsSinceEpoch,
    });
  }

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

  // ════════════════════════════════════════════════════════════
  // 歌单歌曲操作
  // ════════════════════════════════════════════════════════════

  Future<List<String>> getPlaylistSongIds(String playlistId) async {
    final data = await _db.getPlaylistSongs(playlistId);
    return data.map((e) => e['song_id'] as String).toList();
  }

  Future<void> addSong(String playlistId, String songId) async {
    await _db.addSongToPlaylist(playlistId, songId);
  }

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

  Future<void> reorderSongs(
      String playlistId, int oldIndex, int newIndex) async {
    if (oldIndex == newIndex) return;
    final songs = await _db.getPlaylistSongs(playlistId);
    if (oldIndex < 0 ||
        oldIndex >= songs.length ||
        newIndex < 0 ||
        newIndex >= songs.length) {
      return;
    }
    final items = songs.map((e) => e['song_id'] as String).toList();
    final item = items.removeAt(oldIndex);
    items.insert(newIndex, item);
    for (int i = 0; i < items.length; i++) {
      await _db.removeSongFromPlaylist(playlistId, items[i]);
      await _db.addSongToPlaylist(playlistId, items[i], orderIndex: i);
    }
  }

  Future<void> clearPlaylist(String playlistId) async {
    await _db.clearPlaylist(playlistId);
  }

  // ════════════════════════════════════════════════════════════
  // 收藏操作
  // ════════════════════════════════════════════════════════════

  Future<List<String>> getFavorites() async {
    final data = await _db.getFavorites();
    return data.map((e) => e['song_id'] as String).toList();
  }

  Future<bool> isFavorite(String songId) async {
    return await _db.isFavorite(songId);
  }

  Future<void> addFavorite(String songId) async {
    await _db.addFavorite(songId);
  }

  Future<void> removeFavorite(String songId) async {
    await _db.removeFavorite(songId);
  }

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