import 'package:dio/dio.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../auth/auth_state.dart';
import '../config/app_config.dart';
import '../errors/error_reporter.dart';
import '../../providers/connectivity_provider.dart';

/// Public Dio instance for unauthenticated calls (login / refresh)
final _publicDio = Dio(BaseOptions(
  baseUrl: AppConfig.apiBaseUrl,
  connectTimeout: const Duration(seconds: 5),
  receiveTimeout: const Duration(seconds: 15),
));

final apiClientProvider = Provider<ApiClient>((ref) {
  // 只监听登录/登出，不监听 token 内容变化。
  // token refresh 只改 accessToken，isLoggedIn 不变，provider 不重建，
  // 避免旧 Dio 被 close 后还在执行 fetch 导致 "adapter was closed"。
  ref.watch(authStateProvider.select((s) => s.isLoggedIn));
  final user = ref.read(authStateProvider).user;

  final client = ApiClient(
    token: user?.accessToken,
    refreshToken: user?.refreshToken,
    onTokenRefreshed: (newToken) {
      ref.read(authStateProvider.notifier).updateAccessToken(newToken);
    },
    onAuthFailed: () {
      if (ref.read(authStateProvider).isLoggedIn) {
        ref.read(authStateProvider.notifier).logout();
      }
    },
    onConnectionError: () {
      ref.read(connectivityProvider.notifier).forceCheck();
    },
  );
  ref.onDispose(client.dispose);
  return client;
});

class ApiClient {
  late final Dio _dio;
  bool _disposed = false;

  ApiClient({
    String? token,
    String? refreshToken,
    void Function(String newToken)? onTokenRefreshed,
    void Function()? onAuthFailed,
    void Function()? onConnectionError,
  }) {
    _dio = Dio(BaseOptions(
      baseUrl: AppConfig.apiBaseUrl,
      connectTimeout: const Duration(seconds: 5),
      receiveTimeout: const Duration(seconds: 15),
      headers: {
        if (token != null) 'Authorization': 'Bearer $token',
      },
    ));

    // 网络错误 + 401 拦截器
    _dio.interceptors.add(
      InterceptorsWrapper(
        onError: (DioException e, ErrorInterceptorHandler handler) async {
          if (_disposed) return handler.next(e);

          // 网络层错误（连接拒绝、超时等）→ 立即触发连通性检测
          final isNetworkError = e.type == DioExceptionType.connectionError ||
              e.type == DioExceptionType.connectionTimeout ||
              e.type == DioExceptionType.receiveTimeout ||
              e.type == DioExceptionType.sendTimeout;
          if (isNetworkError) {
            onConnectionError?.call();
            return handler.next(e);
          }

          // 服务端 5xx 错误上报（4xx 是业务/权限错误，不上报）
          final statusCode = e.response?.statusCode ?? 0;
          if (statusCode >= 500) {
            reportError(
              '[${e.requestOptions.method}] ${e.requestOptions.path} → $statusCode',
              e.stackTrace,
              errorType: ErrorType.apiError,
            );
          }

          if (e.response?.statusCode == 401 && (refreshToken ?? '').isNotEmpty) {
            debugPrint('[ApiClient] got 401 on ${e.requestOptions.path}, trying refresh...');
            try {
              final resp = await _publicDio.post('/auth/refresh', data: {
                'refresh_token': refreshToken,
              });
              final newToken = resp.data['data']['access_token'] as String;
              _dio.options.headers['Authorization'] = 'Bearer $newToken';
              if (!_disposed) onTokenRefreshed?.call(newToken);
              final opts = e.requestOptions;
              opts.headers['Authorization'] = 'Bearer $newToken';
              final retryResp = await _dio.fetch(opts);
              return handler.resolve(retryResp);
            } catch (refreshErr) {
              debugPrint('[ApiClient] refresh failed: $refreshErr');
              if (!_disposed) onAuthFailed?.call();
            }
          } else if (e.response?.statusCode == 401) {
            debugPrint('[ApiClient] got 401 on ${e.requestOptions.path}, no refresh token');
          }
          return handler.next(e);
        },
      ),
    );
  }

  /// 取消所有进行中的请求，标记实例为已废弃
  void dispose() {
    _disposed = true;
    _dio.close(force: true);
  }

  Future<Response> get(String path, {Map<String, dynamic>? params}) =>
      _dio.get(path, queryParameters: params);

  Future<List<int>> getBytes(String path) async {
    final resp = await _dio.get<List<int>>(path,
        options: Options(responseType: ResponseType.bytes));
    return resp.data ?? [];
  }

  Future<Response> post(String path, {dynamic data}) =>
      _dio.post(path, data: data);

  Future<Response> put(String path, {dynamic data}) =>
      _dio.put(path, data: data);

  Future<Response> patch(String path, {dynamic data}) =>
      _dio.patch(path, data: data);

  Future<Response> delete(String path) => _dio.delete(path);
}

/// Unauthenticated client for login/refresh
class PublicApiClient {
  static Future<Response> post(String path, {dynamic data}) =>
      _publicDio.post(path, data: data);
}