payfrit-app/lib/services/auth_storage.dart

import 'package:shared_preferences/shared_preferences.dart';

class AuthStorage {
  static const _keyUserId = 'auth_user_id';
  static const _keyUserToken = 'auth_user_token';

  /// Save authentication credentials
  static Future<void> saveAuth({
    required int userId,
    required String token,
  }) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setInt(_keyUserId, userId);
    await prefs.setString(_keyUserToken, token);
  }

  /// Load saved authentication credentials
  static Future<AuthCredentials?> loadAuth() async {
    final prefs = await SharedPreferences.getInstance();
    final userId = prefs.getInt(_keyUserId);
    final token = prefs.getString(_keyUserToken);

    if (userId != null && token != null && token.isNotEmpty) {
      return AuthCredentials(userId: userId, token: token);
    }
    return null;
  }

  /// Clear authentication credentials (logout)
  static Future<void> clearAuth() async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.remove(_keyUserId);
    await prefs.remove(_keyUserToken);
  }
}

class AuthCredentials {
  final int userId;
  final String token;

  const AuthCredentials({
    required this.userId,
    required this.token,
  });
}