import 'package:flutter_secure_storage/flutter_secure_storage.dart';

/// 登录会话持久化：token + 手机号存 secure storage。
/// 启动时读取判断是否已登录；登出/401 时清除回登录页。
class SessionStore {
  static const _storage = FlutterSecureStorage();
  static const _tokenKey = 'auth_token';
  static const _phoneKey = 'auth_phone';

  static String? _cachedToken;
  static String? _cachedPhone;

  Future<String?> readToken() async {
    if (_cachedToken != null) return _cachedToken;
    return _cachedToken = await _storage.read(key: _tokenKey);
  }

  Future<String?> readPhone() async {
    if (_cachedPhone != null) return _cachedPhone;
    return _cachedPhone = await _storage.read(key: _phoneKey);
  }

  Future<void> save(String phone, String token) async {
    _cachedPhone = phone;
    _cachedToken = token;
    await _storage.write(key: _phoneKey, value: phone);
    await _storage.write(key: _tokenKey, value: token);
  }

  Future<void> clear() async {
    _cachedPhone = null;
    _cachedToken = null;
    await _storage.delete(key: _phoneKey);
    await _storage.delete(key: _tokenKey);
  }
}