import 'package:flutter/foundation.dart';

import '../payment/license_service.dart';
import '../payment/models.dart';
import '../payment/order_api.dart';

/// 主界面状态：到期时间展示 + 搜索入口强制校验 + 退出登录
class HomeViewModel extends ChangeNotifier {
  final LicenseService licenseService;

  LicenseStatus? _license;
  bool _loading = true;
  bool _verifying = false;
  String? _error;
  bool _sessionExpired = false;

  LicenseStatus? get license => _license;
  bool get loading => _loading;
  bool get verifying => _verifying;
  String? get error => _error;
  bool get sessionExpired => _sessionExpired;

  HomeViewModel({required this.licenseService});

  /// 进入主界面/支付返回后刷新（本地缓存优先，服务端为准）
  Future<void> refresh() async {
    _loading = true;
    _error = null;
    notifyListeners();
    try {
      _license = await licenseService.check();
    } catch (_) {
      // check 内部已兜底，这里仅防御
    } finally {
      _loading = false;
      notifyListeners();
    }
  }

  /// 搜索按钮：强制服务端校验授权，active 才允许进入相机。
  /// 网络失败/会话失效一律不放行；返回值表示是否可进入。
  Future<bool> verifyForCamera() async {
    _verifying = true;
    _sessionExpired = false;
    _error = null;
    notifyListeners();
    try {
      final license = await licenseService.verifyServer();
      _license = license;
      return license.isActive;
    } on SessionExpiredException {
      _sessionExpired = true;
      return false;
    } on OrderApiException catch (e) {
      _error = e.message;
      return false;
    } finally {
      _verifying = false;
      notifyListeners();
    }
  }

  void clearSessionExpired() {
    _sessionExpired = false;
    notifyListeners();
  }
}