import 'package:dio/dio.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../core/network/api_exception.dart';
import '../core/network/dio_client.dart';
import '../models/auth_response.dart';

final authApiProvider = Provider<AuthApi>((ref) => AuthApi(ref.watch(dioProvider)));

class AuthApi {
  final Dio _dio;

  AuthApi(this._dio);

  /// 登录 → {token, username, nickname}
  Future<AuthResponse> login(String username, String password) async {
    try {
      final res = await _dio.post('/auth/login', data: {
        'username': username,
        'password': password,
      });
      return AuthResponse.fromJson(_map(res.data));
    } on DioException catch (e) {
      throw _unwrap(e);
    }
  }

  /// 注册 → {token, username, nickname}
  Future<AuthResponse> register(String username, String password, String nickname) async {
    try {
      final res = await _dio.post('/auth/register', data: {
        'username': username,
        'password': password,
        'nickname': nickname,
      });
      return AuthResponse.fromJson(_map(res.data));
    } on DioException catch (e) {
      throw _unwrap(e);
    }
  }

  /// 拉当前用户资料。冷启动时本地缓存的 userInfo 可能过期（在别处换过头像），
  /// 用它刷一次。
  Future<AuthResponse> profile() async {
    try {
      final res = await _dio.get('/auth/profile');
      return AuthResponse.fromJson(_map(res.data));
    } on DioException catch (e) {
      throw _unwrap(e);
    }
  }

  /// 更新资料。目前只有头像。
  ///
  /// [avatar] 传 null = 不改动；[clearAvatar] 传 true = 清空。
  /// 这两种语义要分清 —— 混淆会让「只改昵称」意外把头像清掉。
  Future<AuthResponse> updateProfile({String? avatar, bool clearAvatar = false}) async {
    try {
      final res = await _dio.put('/auth/profile', data: {
        'avatar': ?avatar,
        if (clearAvatar) 'clearAvatar': true,
      });
      return AuthResponse.fromJson(_map(res.data));
    } on DioException catch (e) {
      throw _unwrap(e);
    }
  }

  /// 上传头像，返回**相对路径**（再由 updateProfile 提交）。
  Future<String> uploadAvatar(String filePath) async {
    try {
      final form = FormData.fromMap({
        'file': await MultipartFile.fromFile(filePath, filename: _fileName(filePath)),
      });
      final res = await _dio.post<dynamic>(
        '/auth/avatar',
        data: form,
        options: Options(receiveTimeout: const Duration(seconds: 60)),
      );
      final data = res.data;
      if (data is Map && data['path'] != null) {
        return data['path'].toString();
      }
      throw ApiException(-1, '上传失败：服务端没返回路径');
    } on DioException catch (e) {
      throw _unwrap(e);
    }
  }

  /// 从路径取文件名，后端靠扩展名判断类型
  static String _fileName(String path) {
    final normalized = path.replaceAll('\\', '/');
    final name = normalized.substring(normalized.lastIndexOf('/') + 1);
    return name.isEmpty ? 'avatar.jpg' : name;
  }

  Map<String, dynamic> _map(Object? data) {
    if (data is Map<String, dynamic>) return data;
    throw ApiException(-1, '响应格式异常');
  }

  Never _unwrap(DioException e) {
    final err = e.error;
    if (err is ApiException) throw err;
    throw ApiException(-1, '请求失败');
  }
}