class VhsMapAccess {
  VhsMapAccess(this.uri);

  final Uri uri;
  static const int maxAuthenticationAttempts = 3;
  int _authenticationAttempts = 0;

  static bool _isValidUri(Uri value) =>
      value.scheme == 'https' &&
      value.hasAuthority &&
      value.host.isNotEmpty &&
      value.userInfo.isEmpty &&
      value.port > 0 &&
      value.port <= 65535;

  bool get isValid => _isValidUri(uri);

  bool allowsNavigation(Uri target) =>
      isValid && _isValidUri(target) && target.origin == uri.origin;

  // Die WebView liefert bei Authentifizierungsanfragen nur Host und Realm.
  bool allowsAuthentication(String host) =>
      isValid && host.toLowerCase() == uri.host.toLowerCase();

  bool tryAuthentication(String host) {
    if (!allowsAuthentication(host) ||
        _authenticationAttempts >= maxAuthenticationAttempts) {
      return false;
    }
    _authenticationAttempts++;
    return true;
  }
}