import 'package:finlytic_app/core/network/api_client.dart';
import 'package:finlytic_app/core/services/secure_storage_service.dart';
import 'package:finlytic_app/features/auth/models/user_model.dart';

class AuthRepository {
  final ApiClient apiClient;
  final SecureStorageService storageService;

  AuthRepository({
    required this.apiClient,
    required this.storageService,
  });

  Future<UserModel?> checkAuthStatus() async {
    final token = await storageService.getToken();
    if (token == null || token.isEmpty) {
      return null;
    }
    try {
      final response = await apiClient.get('/api/v1/user/me');
      if (response.statusCode == 200 && response.data != null) {
        return UserModel.fromJson(response.data, token: token);
      } else {
        await storageService.clearAll();
        return null;
      }
    } catch (_) {
      await storageService.clearAll();
      return null;
    }
  }

  Future<UserModel> login(String email, String password) async {
    final res = await apiClient.post('/api/v1/auth/login', data: {
      'email': email,
      'password': password,
    });
    if (res.statusCode == 200 && res.data != null) {
      final token = res.data['token']?.toString() ?? '';

      if (res.data['requiresPasswordChange'] == true) {
        // The backend already issues a valid JWT even when a password change is required, so it must be
        // persisted here: the subsequent change-initial-password call is an [Authorize]-protected endpoint
        // and has no other way to authenticate itself.
        await storageService.saveToken(token);
        throw RequiresPasswordChangeException(res.data['userId']?.toString() ?? '');
      }

      final user = UserModel.fromJson(res.data, token: token);
      await storageService.saveToken(token);
      await storageService.saveUserEmail(user.email);
      return user;
    } else {
      throw Exception('Ungültige Anmeldedaten');
    }
  }

  Future<bool> changeInitialPassword(String userId, String newPassword) async {
    final res = await apiClient.post('/api/v1/auth/change-initial-password', data: {
      'userId': userId,
      'newPassword': newPassword,
    });
    return res.statusCode == 200;
  }

  Future<void> logout() async {
    await storageService.clearAll();
  }
}

class RequiresPasswordChangeException implements Exception {
  final String userId;
  RequiresPasswordChangeException(this.userId);
}