import 'package:patbond_flutter/core/network/api_client.dart';
import 'package:patbond_flutter/core/network/api_exception.dart';
import 'package:patbond_flutter/features/community/community_exceptions.dart';
import 'package:patbond_flutter/features/community/community_models.dart';
import 'package:uuid/uuid.dart';

/// community / media 域仓库接口（契约 v1.3.0 的 13 路径 / 19 操作全覆盖；
/// 页面依赖此抽象，widget / controller 测试注入假实现）。
///
/// media 两步上传本单只到协议层（创建上传 / 确认上传）；预签名 PUT
/// 直传对象存储不走业务信封与 Bearer 鉴权，属 T3-13 独立客户端。
abstract class CommunityRepository {
  // ---- media 两步上传（协议层）----
  Future<MediaUploadCredentials> createMediaUpload(
    CreateMediaUploadRequest request,
  );
  Future<MediaAsset> completeMediaUpload(String assetId);

  // ---- 帖子 CRUD / 发布 ----
  Future<Post> createPost(CreatePostRequest request);
  Future<Post> getPost(String postId);
  Future<Post> updatePost(String postId, UpdatePostRequest request);
  Future<void> deletePost(String postId);
  Future<CursorPage<Post>> listMyPosts({
    int? limit,
    String? cursor,
    PostStatus? status,
  });

  // ---- Feed（cursor 分页）----
  Future<CursorPage<FeedCard>> getFeed({int? limit, String? cursor});

  // ---- 评论 ----
  Future<CursorPage<PostComment>> listComments(
    String postId, {
    int? limit,
    String? cursor,
  });
  Future<PostComment> createComment(
    String postId,
    CreateCommentRequest request,
  );
  Future<void> deleteComment(String commentId);

  // ---- 点赞 / 收藏（PUT/DELETE 语义幂等，响应权威终态）----
  Future<LikeState> likePost(String postId);
  Future<LikeState> unlikePost(String postId);
  Future<BookmarkState> bookmarkPost(String postId);
  Future<BookmarkState> unbookmarkPost(String postId);
  Future<CursorPage<FeedCard>> listMyBookmarks({int? limit, String? cursor});

  // ---- 关注 ----
  Future<FollowState> followUser(String userId);
  Future<FollowState> unfollowUser(String userId);
  Future<FollowStats> getFollowStats(String userId);
}

/// 基于 [ApiClient] 的实现。全部端点走 Bearer 鉴权（复用既有 token
/// 拦截 + 401/40101 单飞刷新重放）；community 域业务错误码升格为类型化异常。
///
/// 幂等：createPost / createComment 两个 POST 按契约**必带**
/// `Idempotency-Key`（1~128 字符；每次逻辑提交换新键；token 刷新后的
/// 自动重放沿用同一个键——键在本层每次调用生成一次，重放走同一 headers）。
/// 点赞/收藏/关注为 PUT/DELETE 语义幂等，无需幂等键。
class ApiCommunityRepository implements CommunityRepository {
  ApiCommunityRepository({required this._api, this._uuid = const Uuid()});

  final ApiClient _api;
  final Uuid _uuid;

  Future<Object?> _request(
    String path, {
    String method = 'GET',
    Object? body,
    Map<String, Object?>? query,
    bool idempotent = false,
  }) async {
    try {
      return await _api.request(
        path,
        method: method,
        body: body,
        query: query,
        headers: idempotent ? {'Idempotency-Key': _uuid.v4()} : null,
        requiresAuth: true,
      );
    } on ApiBusinessException catch (error) {
      throw mapCommunityBusinessException(error);
    }
  }

  Map<String, dynamic> _asMap(Object? data) => data! as Map<String, dynamic>;

  // ---- media ----

  @override
  Future<MediaUploadCredentials> createMediaUpload(
    CreateMediaUploadRequest request,
  ) async {
    final data = await _request(
      '/api/v1/media/uploads',
      method: 'POST',
      body: request.toJson(),
    );
    return MediaUploadCredentials.fromJson(_asMap(data));
  }

  @override
  Future<MediaAsset> completeMediaUpload(String assetId) async {
    // 幂等由服务端保证：已 ready 重复 confirm 返回 200 同一 asset。
    final data = await _request(
      '/api/v1/media/uploads/$assetId/complete',
      method: 'POST',
    );
    return MediaAsset.fromJson(_asMap(data));
  }

  // ---- posts ----

  @override
  Future<Post> createPost(CreatePostRequest request) async {
    final data = await _request(
      '/api/v1/posts',
      method: 'POST',
      body: request.toJson(),
      idempotent: true,
    );
    return Post.fromJson(_asMap(data));
  }

  @override
  Future<Post> getPost(String postId) async {
    final data = await _request('/api/v1/posts/$postId');
    return Post.fromJson(_asMap(data));
  }

  @override
  Future<Post> updatePost(String postId, UpdatePostRequest request) async {
    final data = await _request(
      '/api/v1/posts/$postId',
      method: 'PATCH',
      body: request.toJson(),
    );
    return Post.fromJson(_asMap(data));
  }

  @override
  Future<void> deletePost(String postId) async {
    await _request('/api/v1/posts/$postId', method: 'DELETE');
  }

  @override
  Future<CursorPage<Post>> listMyPosts({
    int? limit,
    String? cursor,
    PostStatus? status,
  }) async {
    final data = await _request(
      '/api/v1/me/posts',
      query: {
        'limit': ?limit,
        'cursor': ?cursor,
        if (status != null) 'status': status.name,
      },
    );
    return CursorPage.fromJson(_asMap(data), Post.fromJson);
  }

  // ---- feed ----

  @override
  Future<CursorPage<FeedCard>> getFeed({int? limit, String? cursor}) async {
    final data = await _request(
      '/api/v1/feed',
      query: {'limit': ?limit, 'cursor': ?cursor},
    );
    return CursorPage.fromJson(_asMap(data), FeedCard.fromJson);
  }

  // ---- comments ----

  @override
  Future<CursorPage<PostComment>> listComments(
    String postId, {
    int? limit,
    String? cursor,
  }) async {
    final data = await _request(
      '/api/v1/posts/$postId/comments',
      query: {'limit': ?limit, 'cursor': ?cursor},
    );
    return CursorPage.fromJson(_asMap(data), PostComment.fromJson);
  }

  @override
  Future<PostComment> createComment(
    String postId,
    CreateCommentRequest request,
  ) async {
    final data = await _request(
      '/api/v1/posts/$postId/comments',
      method: 'POST',
      body: request.toJson(),
      idempotent: true,
    );
    return PostComment.fromJson(_asMap(data));
  }

  @override
  Future<void> deleteComment(String commentId) async {
    // 顶层短路径先例：commentId 全局唯一。
    await _request('/api/v1/comments/$commentId', method: 'DELETE');
  }

  // ---- interactions ----

  @override
  Future<LikeState> likePost(String postId) async {
    final data = await _request('/api/v1/posts/$postId/like', method: 'PUT');
    return LikeState.fromJson(_asMap(data));
  }

  @override
  Future<LikeState> unlikePost(String postId) async {
    final data = await _request('/api/v1/posts/$postId/like', method: 'DELETE');
    return LikeState.fromJson(_asMap(data));
  }

  @override
  Future<BookmarkState> bookmarkPost(String postId) async {
    final data = await _request(
      '/api/v1/posts/$postId/bookmark',
      method: 'PUT',
    );
    return BookmarkState.fromJson(_asMap(data));
  }

  @override
  Future<BookmarkState> unbookmarkPost(String postId) async {
    final data = await _request(
      '/api/v1/posts/$postId/bookmark',
      method: 'DELETE',
    );
    return BookmarkState.fromJson(_asMap(data));
  }

  @override
  Future<CursorPage<FeedCard>> listMyBookmarks({
    int? limit,
    String? cursor,
  }) async {
    final data = await _request(
      '/api/v1/me/bookmarks',
      query: {'limit': ?limit, 'cursor': ?cursor},
    );
    return CursorPage.fromJson(_asMap(data), FeedCard.fromJson);
  }

  // ---- follows ----

  @override
  Future<FollowState> followUser(String userId) async {
    final data = await _request('/api/v1/users/$userId/follow', method: 'PUT');
    return FollowState.fromJson(_asMap(data));
  }

  @override
  Future<FollowState> unfollowUser(String userId) async {
    final data = await _request(
      '/api/v1/users/$userId/follow',
      method: 'DELETE',
    );
    return FollowState.fromJson(_asMap(data));
  }

  @override
  Future<FollowStats> getFollowStats(String userId) async {
    final data = await _request('/api/v1/users/$userId/follow-stats');
    return FollowStats.fromJson(_asMap(data));
  }
}