import 'package:dio/dio.dart';

import '../config/app_config.dart';
import '../storage/token_storage.dart';
import 'api_exception.dart';

/// 统一网络客户端：JWT 拦截器 + 统一响应解包（code != 0 抛 ApiException）
class ApiClient {
  final TokenStorage _tokenStorage;
  late final Dio _dio;

  /// 401 时回调（登出）
  void Function()? onUnauthorized;

  // ignore: prefer_initializing_formals
  ApiClient({required TokenStorage tokenStorage, Dio? dio})
      : _tokenStorage = tokenStorage {
    _dio = dio ??
        Dio(BaseOptions(
          baseUrl: AppConfig.baseUrl,
          connectTimeout: const Duration(seconds: 10),
          receiveTimeout: const Duration(seconds: 60),
        ));
    _dio.interceptors.add(InterceptorsWrapper(
      onRequest: (options, handler) {
        final token = _tokenStorage.token;
        if (token != null && token.isNotEmpty) {
          options.headers['Authorization'] = 'Bearer $token';
        }
        handler.next(options);
      },
      onError: (e, handler) {
        if (e.response?.statusCode == 401) onUnauthorized?.call();
        handler.next(e);
      },
    ));
  }

  Future<T> post<T>(String path, Map<String, dynamic> body,
      {T Function(dynamic data)? parse}) async {
    final res = await _dio.post(path, data: body);
    return _unwrap(res, parse);
  }

  Future<T> get<T>(String path,
      {Map<String, dynamic>? query, T Function(dynamic data)? parse}) async {
    final res = await _dio.get(path, queryParameters: query);
    return _unwrap(res, parse);
  }

  /// multipart 上传：fields 为文本字段，fileField 为文件字段名
  Future<T> upload<T>(String path, Map<String, dynamic> fields,
      String fileField, String filePath,
      {T Function(dynamic data)? parse}) async {
    final form = FormData.fromMap({
      ...fields,
      fileField: await MultipartFile.fromFile(filePath),
    });
    final res = await _dio.post(path, data: form);
    return _unwrap(res, parse);
  }

  T _unwrap<T>(Response res, T Function(dynamic data)? parse) {
    final data = res.data;
    if (data is! Map<String, dynamic>) {
      throw ApiException(-1, '响应格式错误');
    }
    final code = data['code'] as int? ?? -1;
    final message = data['message'] as String? ?? '';
    if (code != 0) {
      throw ApiException(code, message);
    }
    final payload = data['data'];
    if (parse != null) return parse(payload);
    return payload as T;
  }
}