import 'package:flutter/foundation.dart';
import 'package:dio/dio.dart';
import '../core/api/api_client.dart';
import '../core/auth/auth_state.dart';

typedef AuthLoginFn = Future<AuthUser> Function({
  required String shopCode,
  required String username,
  required String password,
});

class AuthException implements Exception {
  final String message;
  const AuthException(this.message);
  @override
  String toString() => message;
}

class AuthRepository {
  @visibleForTesting
  static AuthLoginFn? loginOverride;

  /// POST /api/v1/auth/login
  /// Request:  { shop_code, username, password }
  /// Response: { data: { access_token, refresh_token, expires_in, user: { id, username, real_name, role } } }
  static Future<AuthUser> login({
    required String shopCode,
    required String username,
    required String password,
  }) async {
    final override = loginOverride;
    if (override != null) {
      return override(
        shopCode: shopCode,
        username: username,
        password: password,
      );
    }
    try {
      final resp = await PublicApiClient.post('/auth/login', data: {
        'shop_code': shopCode,
        'username': username,
        'password': password,
      });

      final data = resp.data['data'] as Map<String, dynamic>;
      final user = data['user'] as Map<String, dynamic>;

      return AuthUser(
        accessToken: data['access_token'] as String,
        refreshToken: data['refresh_token'] as String,
        username: user['username'] as String,
        realName: user['real_name'] as String? ?? username,
        shopNo: shopCode,
        shopId: (data['shop_id'] as num).toInt(),
        role: user['role'] as String? ?? 'operator',
      );
    } on DioException catch (e) {
      final msg = e.response?.data?['error'] as String?;
      throw AuthException(msg ?? _networkError(e));
    }
  }

  static String _networkError(DioException e) {
    switch (e.type) {
      case DioExceptionType.connectionTimeout:
      case DioExceptionType.receiveTimeout:
        return '连接超时，请检查网络';
      case DioExceptionType.connectionError:
        return '无法连接到服务器（localhost:8080），请先启动后端';
      default:
        return '网络错误：${e.message}';
    }
  }
}