/// 媒体项：digitize=图片URL，reconfigure=视频URL（需生成封面）
class GalleryMediaItem {
  const GalleryMediaItem({
    this.imageUrl,
    this.videoUrl,
  }) : assert(imageUrl != null || videoUrl != null);

  final String? imageUrl; // digitize
  final String? videoUrl; // reconfigure - 视频地址，用于生成封面

  bool get isVideo => videoUrl != null && (imageUrl == null || imageUrl!.isEmpty);
}

/// 我的任务项（V2 字段映射）
class GalleryTaskItem {
  const GalleryTaskItem({
    required this.taskId,
    required this.state,
    required this.taskType,
    required this.createTime,
    required this.mediaItems,
  });

  final int taskId;
  final String state;
  final int taskType;
  final int createTime;
  final List<GalleryMediaItem> mediaItems;

  factory GalleryTaskItem.fromJson(Map<String, dynamic> json) {
    final downsample = json['downsample'] as List<dynamic>? ?? [];
    final items = <GalleryMediaItem>[];
    for (final item in downsample) {
      if (item is String) {
        items.add(GalleryMediaItem(imageUrl: item));
      } else if (item is Map<String, dynamic>) {
        final digitize = item['digitize'] as String?;
        final reconfigure = item['reconfigure'] as String?;
        // digitize=图片, reconfigure=视频；优先用图片，否则用视频生成封面
        if (digitize != null && digitize.isNotEmpty) {
          items.add(GalleryMediaItem(imageUrl: digitize));
        } else if (reconfigure != null && reconfigure.isNotEmpty) {
          items.add(GalleryMediaItem(videoUrl: reconfigure));
        }
      }
    }
    return GalleryTaskItem(
      taskId: (json['tree'] as num?)?.toInt() ?? 0,
      state: json['listing']?.toString() ?? '',
      taskType: (json['cipher'] as num?)?.toInt() ?? 0,
      createTime: (json['discover'] as num?)?.toInt() ?? 0,
      mediaItems: items,
    );
  }
}