findSecondary static method

Future<String?> findSecondary(String atsign, String? rootDomain, int rootPort)

Implementation

static Future<String?> findSecondary(
    String atsign, String? rootDomain, int rootPort) async {
  String? response;
  SecureSocket? socket;
  try {
    AtSignLogger('AtLookup')
        .finer('AtLookup.findSecondary received atsign: $atsign');
    if (atsign.startsWith('@')) atsign = atsign.replaceFirst('@', '');
    var answer = '';
    String? secondary;
    var ans = false;
    var prompt = false;
    var once = true;
    // ignore: omit_local_variable_types
    socket = await SecureSocket.connect(rootDomain, rootPort);
    // listen to the received data event stream
    socket.listen((List<int> event) async {
      answer = utf8.decode(event);

      if (answer.endsWith('@') && prompt == false && once == true) {
        prompt = true;
        socket!.write('$atsign\n');
        await socket.flush();
        once = false;
      }

      if (answer.contains(':')) {
        answer = answer.replaceFirst('\r\n@', '');
        answer = answer.replaceFirst('@', '');
        answer = answer.replaceAll('@', '');
        secondary = answer.trim();
        ans = true;
      } else if (answer.startsWith('null')) {
        secondary = null;
        ans = true;
      }
    });
    // wait 5 seconds
    for (var i = 0; i < 100; i++) {
      await Future.delayed(Duration(milliseconds: 50));
      if (ans) {
        response = secondary;
        socket.write('@exit\n');
        await socket.flush();
        socket.destroy();
        AtSignLogger('AtLookup').finer(
            'AtLookup.findSecondary got answer: $secondary and closing connection');
        return response;
      }
    }
    // .. and close the socket
    await socket.flush();
    socket.destroy();
    throw Exception('AtLookup.findSecondary timed out');
  } on Exception catch (exception) {
    AtSignLogger('AtLookup').severe('AtLookup.findSecondary connection to ' +
        rootDomain! +
        ' exception: ' +
        exception.toString());
    if (socket != null) {
      socket.destroy();
    }
  } catch (error) {
    AtSignLogger('AtLookup').severe(
        'AtLookup.findSecondary connection to root server failed with error: $error');
    if (socket != null) {
      socket.destroy();
    }
  }
  return response;
}