// 功能描述：装配用户端依赖，并统一管理登录、退出和失效会话。
// 版本：1.1.0

import 'package:flutter/foundation.dart';

import '../data/repositories/client_repository.dart';
import '../data/services/api_client.dart';
import '../data/services/secure_session_store.dart';

class AppDependencies {
  AppDependencies({
    required this.session,
    required this.repository,
  });

  final UserSession session;
  final ClientRepository repository;

  static Future<AppDependencies> create() async {
    final store = SecureSessionStore();
    final session = UserSession(store);
    await session.restore();
    final api = ApiClient(
      () => session.token,
      onUnauthorized: session.invalidate,
    );
    return AppDependencies(session: session, repository: ClientRepository(api));
  }
}

/// 管理内存令牌、持久化令牌以及会话失效通知。
class UserSession extends ChangeNotifier {
  UserSession(this._store);

  static const _root = '/heqi/client/v1/user';
  final SessionStore _store;
  String _token = '';
  bool _expired = false;
  Future<void> _pendingClear = Future<void>.value();

  String get token => _token;
  bool get isAuthenticated => _token.isNotEmpty;
  bool get hasExpired => _expired;

  /// 从安全存储恢复令牌；是否有效由后续受保护接口响应确认。
  Future<void> restore() async {
    _token = await _store.readToken() ?? '';
    _expired = false;
  }

  Future<void> login({
    required String phone,
    required String password,
    String? verificationCode,
    String? requestIdentity,
  }) async {
    final api = ApiClient(() => '');
    final verification = verificationCode != null && verificationCode.isNotEmpty;
    final details = jsonMap(
      await api.post(
        '$_root/auth/login',
        authenticated: false,
        body: {
          'phone': phone,
          'mode': verification ? 'verification_code' : 'password',
          'password': verification ? '' : password,
          'code': verificationCode ?? '',
          'request_identity': requestIdentity ?? '',
        },
      ),
    );
    final token = details['access_token'] as String? ?? '';
    if (token.isEmpty) throw const ApiException(500, '登录令牌缺失');

    // 等待旧令牌清理结束，避免迟到的删除任务误删刚写入的新令牌。
    await _pendingClear;
    await _store.writeToken(token);
    _token = token;
    _expired = false;
    notifyListeners();
  }

  Future<String> sendCode(String phone, String purpose) async {
    final api = ApiClient(() => '');
    final details = jsonMap(
      await api.post(
        '$_root/auth/verification-code',
        authenticated: false,
        body: {'phone': phone, 'purpose': purpose},
      ),
    );
    return details['request_identity'] as String? ?? '';
  }

  Future<void> logout() async {
    _token = '';
    _expired = false;
    notifyListeners();
    _pendingClear = _clearStoredToken();
    await _pendingClear;
  }

  /// 仅当服务端拒绝的仍是当前令牌时，使会话失效并通知路由。
  void invalidate(String rejectedToken) {
    if (rejectedToken.isEmpty || rejectedToken != _token || _expired) return;

    _token = '';
    _expired = true;
    notifyListeners();
    _pendingClear = _clearStoredToken();
  }

  /// 尽力删除持久化令牌；失败不得阻塞用户返回登录页。
  Future<void> _clearStoredToken() async {
    try {
      await _store.clear();
    } catch (error, stackTrace) {
      debugPrint('清理失效登录令牌失败：$error');
      debugPrintStack(stackTrace: stackTrace);
    }
  }
}