GatewayConnection.cs

public bool Start()
{
  Gateway = new GatewayConnection(IPAddress, Port, UserName, Password, AppId);

  var connectedEvent = new ManualResetEvent(false);
  var cancel = new CancellationTokenSource();
  var connectedSuccessfully = false;
  var rootNode = default(SiteNode);

  var connectedTCS = new TaskCompletionSource<Result>(cancel);
  var userStatusTCS = new TaskCompletionSource<Result>(cancel);
  var profileTCS = new TaskCompletionSource<Result<SiteNode>>(cancel);

  EventHandler<ConnectionEventArgs> connectedHandler = (s, e) =>
  {
      var connection = (GatewayConnection)s;
      Log.Info($"Start - ConnectionStatus: {connection.Status}");
      connectedTCS.TrySetResult(Result.Create(connection.Status == ConnectionStatus.Connected));
  };

  EventHandler<AuthenticationEventArgs> userStatusHandler = (s, e) =>
  {
      Log.Info($"Start - UserStatus: {e.AuthenticationStatus }");
      userStatusTCS.TrySetResult(Result.Create(e.AuthenticationStatus == AuthenticationStatus.LoggedIn));
  };

  EventHandler<ProfileEventArgs> profileEventHandler = (s, e) =>
  {
      Log.Info($"Start - profileEvent: {e.EventType}");

      if (Gateway == null)
      {
          profileTCS.TrySetResult(Result.Fail<SiteNode>("Gateway is null"));
          return;
      }

      if (e.EventType == ProfileEventType.ProfileNamesReceived)
      {
          if (!Gateway.SessionContext.ProfileService.ProfileNames.Contains(Profile))
          {
              Log.Error("Wrong profile name");
              profileTCS.TrySetResult(Result.Fail<SiteNode>("Wrong profile name"));
          }
          else
          {
              Thread.Sleep(250);
              Gateway.SessionContext.ProfileService.GetProfile(Profile);
          }
      }
      else if (e.EventType == ProfileEventType.ProfileReceived)
      {
          profileTCS.TrySetResult(Result.Ok(Gateway.SessionContext.ProfileService.CurrentProfile));
      }
  };

  Task.Factory.StartNew(async () =>
  {
      var result = await connectedTCS.Task.ToResult()
          .OnSuccess(async () => await userStatusTCS.Task.ToResult())
          .OnSuccess(async () => await profileTCS.Task.ToResult());

      result.OnSuccess(() =>
      {
          connectedSuccessfully = true;
          rootNode = profileTCS.Task.Result.Value;
          connectedEvent.Set();
      })
      .OnFailure(() =>
      {
          connectedEvent.Set();
      });
  });

  try
  {
      Gateway.ConnectionEvent += connectedHandler;
      Gateway.SessionContext.ProfileService.UserStatusChanged += userStatusHandler;
      Gateway.SessionContext.ProfileService.ProfileEventReceived += profileEventHandler;

      Gateway.Connect();
      connectedEvent.WaitStoppable();
      cancel.Cancel();

      if (connectedSuccessfully)
      {
          Gateway.ConnectionEvent += OnConnectionEvent;
          Gateway.SessionContext.ProfileService.UserStatusChanged += OnUserStatusChanged;
          Gateway.SessionContext.ProfileService.ProfileEventReceived += OnProfileEventReceived;
      }
      else
      {
          Gateway.Disconnect();
          Gateway.Dispose();
          Gateway = null;
      }

      return connectedSuccessfully;
  }
  finally
  {
      Gateway.ConnectionEvent -= connectedHandler;
      Gateway.SessionContext.ProfileService.UserStatusChanged -= userStatusHandler;
      Gateway.SessionContext.ProfileService.ProfileEventReceived -= profileEventHandler;
  }
}