import 'package:flutter/foundation.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import 'package:local_auth/local_auth.dart';
import 'package:device_info_plus/device_info_plus.dart';

class AuthToken {
  static final AuthToken _instance = AuthToken._internal();
  static AuthToken get instance => _instance;
  AuthToken._internal();

  final _storage = const FlutterSecureStorage();
  String? _token;

  String? get token => _token;

  Future<bool> isMobilePlatform() async {
    if (kIsWeb) return false;
    final deviceInfo = DeviceInfoPlugin();
    if (defaultTargetPlatform == TargetPlatform.android) return true;
    if (defaultTargetPlatform == TargetPlatform.iOS) return true;
    return false;
  }

  Future<void> saveToken(String token) async {
    _token = token;
    if (await isMobilePlatform()) {
      await _storage.write(key: 'AuthToken', value: token);
    }
  }

  Future<bool> loadTokenWithBiometric() async {
    if (!await isMobilePlatform()) return false;

    final auth = LocalAuthentication();
    final canAuth =
        await auth.canCheckBiometrics || await auth.isDeviceSupported();
    if (!canAuth) return false;

    final authenticated = await auth.authenticate(
      localizedReason: 'Autenticati per accedere',
      options: const AuthenticationOptions(biometricOnly: true),
    );

    if (authenticated) {
      final stored = await _storage.read(key: 'AuthToken');
      _token = stored;
      return stored != null;
    }

    return false;
  }

  Future<void> clear() async {
    _token = null;
    if (await isMobilePlatform()) {
      await _storage.delete(key: 'AuthToken');
    }
  }
}