import 'package:storage_sdk/storage_sdk.dart';

import 'package:im_app/core/services/socket_manager.dart';
import 'package:im_app/domain/repositories/auth_repository.dart';

/// 退出登录用例
///
/// 封装完整登出流程：
/// 1. 调用服务端 /app/api/auth/logout，清除 token
/// 2. 断开 WebSocket 连接
/// 3. 关闭本地数据库（StorageSdk）
///
/// AuthNotifier.logout() 由 SettingsViewModel 在 UseCase 完成后调用，
/// 触发 go_router 重定向至登录页。
///
/// ## 数据流位置
///
/// ```
/// SettingsViewModel.logout()
///   → ★ LogoutUseCase.execute() ★   ← 你在这里
///     → AuthRepository.logout()     → POST /app/api/auth/logout
///     → SocketManager.disconnect()
///     → StorageSdkLifecycle.closeDatabase()
///   → AuthNotifier.logout()         → 路由跳转 /login
/// ```
class LogoutUseCase {
  final AuthRepository _authRepository;
  final SocketManager _socketManager;
  final StorageSdkApi _storageApi;

  StorageSdkLifecycle get _storageLifecycle => _storageApi as StorageSdkLifecycle;

  const LogoutUseCase({
    required AuthRepository authRepository,
    required SocketManager socketManager,
    required StorageSdkApi storageApi,
  })  : _authRepository = authRepository,
        _socketManager = socketManager,
        _storageApi = storageApi;

  /// 执行完整登出流程
  ///
  /// 抛出异常时，调用方仍应调用 AuthNotifier.logout() 确保本地状态清除。
  Future<void> execute() async {
    // 1. 服务端登出（清除 token）
    await _authRepository.logout();

    // 2. 断开 WebSocket
    await _socketManager.disconnect();

    // 3. 关闭本地数据库
    await _storageLifecycle.closeDatabase();
  }
}