Ensemble/lib/models/recommendation_folder.dart

import 'media_item.dart';

class RecommendationFolder {
  final String itemId;
  final String provider;
  final String name;
  final String? uri;
  final List<MediaItem> items;

  RecommendationFolder({
    required this.itemId,
    required this.provider,
    required this.name,
    this.uri,
    required this.items,
  });

  /// Unique ID for use in row ordering and settings
  /// Uses 'discovery:' prefix to distinguish from static row IDs
  String get rowId => 'discovery:$itemId';

  factory RecommendationFolder.fromJson(Map<String, dynamic> json) {
    final itemsJson = json['items'] as List<dynamic>?;
    final parsedItems = itemsJson
        ?.whereType<Map<String, dynamic>>()
        .map(_parseMediaItemJson)
        .toList() ?? <MediaItem>[];

    return RecommendationFolder(
      itemId: json['item_id']?.toString() ?? json['id']?.toString() ?? '',
      provider: json['provider'] as String? ?? 'unknown',
      name: json['name'] as String? ?? '',
      uri: json['uri'] as String?,
      items: parsedItems,
    );
  }

  Map<String, dynamic> toJson() {
    return {
      'item_id': itemId,
      'provider': provider,
      'name': name,
      if (uri != null) 'uri': uri,
      'items': items.map((item) => item.toJson()).toList(),
    };
  }
}

/// Polymorphic parser for media items in recommendation folders
/// Handles heterogeneous items (playlists, radio, etc.)
MediaItem _parseMediaItemJson(Map<String, dynamic> json) {
  final mediaType = json['media_type'] as String? ?? '';

  switch (mediaType) {
    case 'playlist':
      return Playlist.fromJson(json);
    case 'album':
      return Album.fromJson(json);
    case 'artist':
      return Artist.fromJson(json);
    case 'track':
      return Track.fromJson(json);
    case 'audiobook':
      return Audiobook.fromJson(json);
    default:
      // For radio, podcast, podcast_episode - use MediaItem base class
      return MediaItem.fromJson(json);
  }
}