import '../core/network/api_client.dart';
import '../core/network/endpoints.dart';
import '../models/video_item.dart';
import '../models/watch_result.dart';

/// 视频服务：Feed / 详情 / 观看计费上报（《03-接口文档》第 5 章）
class VideoService {
  VideoService._();

  /// 5.1 Feed 流：type=recommend|latest|hot，游标分页
  static Future<FeedPage> fetchFeed({
    String type = 'recommend',
    String? cursor,
    int limit = 10,
    int? categoryId,
  }) async {
    final data = await ApiClient.get<Map<String, dynamic>>(
      Endpoints.feed,
      queryParameters: {
        'type': type,
        if (cursor != null && cursor.isNotEmpty) 'cursor': cursor,
        'limit': limit,
        if (categoryId != null) 'category_id': categoryId,
      },
    );
    final list = ((data['list'] as List?) ?? const [])
        .whereType<Map<String, dynamic>>()
        .map(VideoItem.fromJson)
        .toList();
    return FeedPage(items: list, nextCursor: data['next_cursor'] as String?);
  }

  /// 5.2 视频详情（登录返回续播进度 my_position）
  static Future<Map<String, dynamic>> fetchDetail(int videoId) =>
      ApiClient.get<Map<String, dynamic>>(Endpoints.videoDetail(videoId));

  /// 当前视频所属系列 + 全部集数（播放器抽屉用）
  static Future<Map<String, dynamic>> fetchVideoSeries(int videoId) async {
    try {
      return await ApiClient.get<Map<String, dynamic>>(Endpoints.videoSeries(videoId));
    } catch (_) {
      return {'has_series': false};
    }
  }

  /// 5.3 观看上报（计费）：开始播放时调用，客户端已按 video_id+日期 本地去重
  static Future<WatchResult> reportWatch(int videoId, {int? position}) async {
    final data = await ApiClient.post<Map<String, dynamic>>(
      Endpoints.videoWatch(videoId),
      data: {if (position != null) 'position': position},
    );
    return WatchResult.fromJson(data);
  }

  /// 5.4 完整观看上报：进度 ≥95% 或自然播完时调用（创作者收益计数）
  /// 返回 credited：今日首次有效为 true，其余情况 false（无需 UI 处理）
  static Future<bool> reportComplete(int videoId, int watchDuration) async {
    final data = await ApiClient.post<Map<String, dynamic>>(
      Endpoints.videoWatchComplete(videoId),
      data: {'watch_duration': watchDuration},
    );
    return (data['credited'] as bool?) ?? false;
  }

  /// 5.29 点赞/取消
  static Future<Map<String, dynamic>> toggleLike(int videoId) =>
      ApiClient.post<Map<String, dynamic>>(Endpoints.videoLike(videoId));

  /// 5.30 收藏/取消
  static Future<Map<String, dynamic>> toggleFavorite(int videoId) =>
      ApiClient.post<Map<String, dynamic>>(Endpoints.videoFavorite(videoId));

  /// 5.12 编辑视频（仅作者）：仅传需要修改的字段
  static Future<void> updateVideo(
    int videoId, {
    String? title,
    String? description,
    int? categoryId,
    List<String>? tags,
  }) async {
    await ApiClient.put<Map<String, dynamic>>(
      Endpoints.videoEdit(videoId),
      data: {
        if (title != null) 'title': title,
        if (description != null) 'description': description,
        if (categoryId != null) 'category_id': categoryId,
        if (tags != null) 'tags': tags,
      },
    );
  }

  /// 5.13 删除视频（仅作者，服务端软删除）
  static Future<void> deleteVideo(int videoId) =>
      ApiClient.delete<Map<String, dynamic>>(Endpoints.videoDelete(videoId));

  /// 5.9 标签视频列表（游客可）：sort=hot（默认）| latest，普通分页
  static Future<TagVideosPage> fetchTagVideos(
    String tagName, {
    String sort = 'hot',
    int page = 1,
    int pageSize = 20,
  }) async {
    final data = await ApiClient.get<Map<String, dynamic>>(
      Endpoints.tagVideos(Uri.encodeComponent(tagName)),
      queryParameters: {'sort': sort, 'page': page, 'page_size': pageSize},
    );
    return TagVideosPage.fromJson(data, fallbackTag: tagName);
  }
}

/// Feed 分页结果（游标）
class FeedPage {
  FeedPage({required this.items, this.nextCursor});

  final List<VideoItem> items;

  /// null 表示没有更多
  final String? nextCursor;
}

/// 标签视频分页结果（普通 page/page_size 分页）
class TagVideosPage {
  TagVideosPage({required this.tag, required this.total, required this.items});

  final String tag;
  final int total;
  final List<VideoItem> items;

  factory TagVideosPage.fromJson(
    Map<String, dynamic> json, {
    String fallbackTag = '',
  }) =>
      TagVideosPage(
        tag: (json['tag'] as String?) ?? fallbackTag,
        total: (json['total'] as num?)?.toInt() ?? 0,
        items: ((json['list'] as List?) ?? const [])
            .whereType<Map<String, dynamic>>()
            .map(VideoItem.fromJson)
            .toList(),
      );
}