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

/// 全局接口异常
class ApiException implements Exception {
  final String result;
  final String message;
  ApiException(this.result, this.message);
  @override
  String toString() => 'ApiException($result): $message';
}

/// HTTP 方法枚举
enum Method { get, post, put, delete }

/// HTTP 管理器 单例
class HttpManager {
  HttpManager._internal() {
    _dio = Dio(BaseOptions(
      connectTimeout: const Duration(milliseconds: 10000),
      receiveTimeout: const Duration(milliseconds: 10000),
      headers: {
        'Content-Type': Headers.formUrlEncodedContentType,
      },
    ));
    _initInterceptors();
  }

  static final HttpManager _instance = HttpManager._internal();
  factory HttpManager() => _instance;
  late final Dio _dio;

  void _initInterceptors() {
    _dio.interceptors
      ..add(LogInterceptor(request: true, responseBody: true, error: true))
      ..add(InterceptorsWrapper(onError: (err, handler) {
        // 全局错误处理，可根据 err.response?.statusCode 或 err.type 做不同处理
        handler.next(err);
      }));
  }

  /// 通用请求方法，返回完整后台 JSON
  Future<Map<String, dynamic>> request(
      String baseUrl,
      String path, {
        Method method = Method.post,
        Map<String, dynamic>? data,
        Map<String, dynamic>? params,
        CancelToken? cancelToken,
      }) async {
    Response resp;
    final url = baseUrl + path;
    final options = Options(
      method: method.name.toUpperCase(),
      contentType: Headers.formUrlEncodedContentType,
    );

    try {
      switch (method) {
        case Method.get:
          resp = await _dio.get(
            url,
            queryParameters: params,
            cancelToken: cancelToken,
            options: options,
          );
          break;
        case Method.put:
          resp = await _dio.put(
            url,
            data: data,
            queryParameters: params,
            cancelToken: cancelToken,
            options: options,
          );
          break;
        case Method.delete:
          resp = await _dio.delete(
            url,
            queryParameters: params,
            cancelToken: cancelToken,
            options: options,
          );
          break;
        case Method.post:
        resp = await _dio.post(
            url,
            data: data,
            queryParameters: params,
            cancelToken: cancelToken,
            options: options,
          );
      }
    } on DioException catch (e) {
      // 网络或服务器错误
      throw ApiException('network_error', e.message ?? e.toString());
    }

    // 解析返回 JSON
    final json = resp.data is Map<String, dynamic>
        ? resp.data as Map<String, dynamic>
        : <String, dynamic>{};
    final result = json['result'] as String?;
    final msg = json['msg'] as String? ?? json['message'] as String? ?? '';
    if (result != 'success') {
      // 非 success 都抛异常
      throw ApiException(result ?? 'unknown', msg);
    }
    return json;
  }
}

/// 上传图片扩展
extension HttpManagerUpload on HttpManager {
  Future<Map<String, dynamic>> uploadFaceImage({
    required String baseUrl,
    required String path,
    required Map<String, dynamic> fromData,
    CancelToken? cancelToken,
  }) async {
    final form = FormData.fromMap(fromData);
    try {
      final resp = await _dio.post(
        baseUrl + path,
        data: form,
        cancelToken: cancelToken,
        options: Options(
          method: Method.post.name.toUpperCase(),
          contentType: 'multipart/form-data',
        ),
      );

      final json = resp.data is Map<String, dynamic>
          ? resp.data as Map<String, dynamic>
          : <String, dynamic>{};

      return json;
    } on DioException catch (e) {
      throw ApiException('network_error', e.message ?? e.toString());
    }
  }
}