import 'package:flutter_secure_storage/flutter_secure_storage.dart';

class TokenStorageService {
  // Singleton pattern (optional but usually handy for services)
  TokenStorageService._internal();

  static final TokenStorageService _instance = TokenStorageService._internal();

  factory TokenStorageService() => _instance;

  static const _tokenKey = 'auth_token';

  // Use const constructor for secure storage
  final FlutterSecureStorage _storage = const FlutterSecureStorage();

  /// Save or update the token
  Future<void> setToken(String token) async {
    await _storage.write(key: _tokenKey, value: token);
  }

  /// Retrieve the stored token (null if none)
  Future<String?> getToken() async {
    return _storage.read(key: _tokenKey);
  }

  /// Delete the token
  Future<void> clearToken() async {
    await _storage.delete(key: _tokenKey);
  }

  /// Optional: check quickly if a token exists
  Future<bool> hasToken() async {
    final token = await getToken();
    return token != null && token.isNotEmpty;
  }
}