static string OpenApiMessageToString(ProtoMessage msg)
        {
            switch ((ProtoOAPayloadType)msg.PayloadType)
            {
            case ProtoOAPayloadType.PROTO_OA_APPLICATION_AUTH_REQ:
                var app_auth_req = ProtoOAApplicationAuthReq.CreateBuilder().MergeFrom(msg.Payload).Build();
                return("AppAuthRequest{clientId:" + app_auth_req.ClientId + ", clientSecret:" + app_auth_req.ClientSecret + "}");

            case ProtoOAPayloadType.PROTO_OA_APPLICATION_AUTH_RES:
                return("ApAuthResponse");

            case ProtoOAPayloadType.PROTO_OA_ACCOUNT_AUTH_REQ:
                var acc_auth_req = ProtoOAAccountAuthReq.CreateBuilder().MergeFrom(msg.Payload).Build();
                return("AccAuthRequest{CtidTraderAccountId:" + acc_auth_req.CtidTraderAccountId + "}");

            case ProtoOAPayloadType.PROTO_OA_ACCOUNT_AUTH_RES:
                return("AccAuthResponse");

            case ProtoOAPayloadType.PROTO_OA_GET_ACCOUNTS_BY_ACCESS_TOKEN_REQ:
                return("GetAccountsByAccessTokenReq");

            case ProtoOAPayloadType.PROTO_OA_GET_ACCOUNTS_BY_ACCESS_TOKEN_RES:
                var accounts_list = ProtoOAGetAccountListByAccessTokenRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                var sbAccounts    = new StringBuilder();
                foreach (var account in accounts_list.CtidTraderAccountList)
                {
                    sbAccounts.Append("ID: " + account.CtidTraderAccountId + (account.IsLive ? " Status: Live" + Environment.NewLine : " Status: Demo " + Environment.NewLine));
                }
                return("GetAccountsByAccessTokenRes{" + sbAccounts.ToString() + "}");

            case ProtoOAPayloadType.PROTO_OA_TRADER_REQ:
                return("PotoOATraderReq");

            case ProtoOAPayloadType.PROTO_OA_SYMBOLS_LIST_REQ:
                return("GetSymbolsList");

            case ProtoOAPayloadType.PROTO_OA_SYMBOLS_LIST_RES:
                var symbols_list = ProtoOASymbolsListRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                var sbSymbols    = new StringBuilder();
                foreach (var symbol in symbols_list.SymbolList)
                {
                    sbSymbols.Append("ID: " + symbol.SymbolId + Environment.NewLine);
                    sbSymbols.Append("Name: " + symbol.SymbolName + Environment.NewLine);
                }
                return("Symbols{" + sbSymbols.ToString() + "}");

            case ProtoOAPayloadType.PROTO_OA_SYMBOL_BY_ID_REQ:
                return("GetSymbolsById");

            case ProtoOAPayloadType.PROTO_OA_SYMBOL_BY_ID_RES:
                var symbol_by_id_list = ProtoOASymbolByIdRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                var sbSymbolByID      = new StringBuilder();
                foreach (var symbol in symbol_by_id_list.SymbolList)
                {
                    sbSymbolByID.Append("ID: " + symbol.SymbolId + Environment.NewLine);
                }
                return("Symbols{" + sbSymbolByID.ToString() + "}");

            case ProtoOAPayloadType.PROTO_OA_EXECUTION_EVENT:
                return(OpenApiExecEventsToString(msg));

            case ProtoOAPayloadType.PROTO_OA_DEAL_LIST_REQ:
                return("DealListRequest{}");

            case ProtoOAPayloadType.PROTO_OA_DEAL_LIST_RES:
                var deal_list = ProtoOADealListRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                var sbDeals   = new StringBuilder();
                foreach (var deal in deal_list.DealList)
                {
                    sbDeals.Append("ID: " + deal.DealId + Environment.NewLine);
                    sbDeals.Append("Status: " + deal.DealStatus + Environment.NewLine);
                    sbDeals.Append("Volume: " + deal.Volume + Environment.NewLine);
                }
                return("DealList{" + sbDeals.ToString() + "}");

            case ProtoOAPayloadType.PROTO_OA_RECONCILE_REQ:
                return("ReconcileRequest{}");

            case ProtoOAPayloadType.PROTO_OA_RECONCILE_RES:
                var reconcile_response = ProtoOAReconcileRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                var sbReconcile        = new StringBuilder();
                foreach (var order in reconcile_response.OrderList)
                {
                    sbReconcile.Append("ID: " + order.OrderId + Environment.NewLine);
                    sbReconcile.Append("Status: " + order.OrderStatus + Environment.NewLine);
                    sbReconcile.Append("Volume: " + order.TradeData.Volume + Environment.NewLine);
                }
                foreach (var position in reconcile_response.PositionList)
                {
                    sbReconcile.Append("ID: " + position.HasPositionId + Environment.NewLine);
                    sbReconcile.Append("Status: " + position.PositionStatus + Environment.NewLine);
                    sbReconcile.Append("Volume: " + position.TradeData.Volume + Environment.NewLine);
                }
                return("ReconcileList{" + sbReconcile.ToString() + "}");

            case ProtoOAPayloadType.PROTO_OA_CASH_FLOW_HISTORY_LIST_REQ:
                return("CashFlowHistoryRequest{}");

            case ProtoOAPayloadType.PROTO_OA_CASH_FLOW_HISTORY_LIST_RES:
                var cashflow_history = ProtoOACashFlowHistoryListRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                var sbDCashflow      = new StringBuilder();
                foreach (var entry in cashflow_history.DepositWithdrawList)
                {
                    sbDCashflow.Append("ID: " + entry.BalanceHistoryId + Environment.NewLine);
                    sbDCashflow.Append("Type: " + entry.OperationType + Environment.NewLine);
                    sbDCashflow.Append("Delta: " + entry.Delta + Environment.NewLine);
                }
                return("CashFlowHistory{" + sbDCashflow.ToString() + "}");

            case ProtoOAPayloadType.PROTO_OA_GET_TRENDBARS_REQ:
                return("GetTrendbarsRequest{}");

            case ProtoOAPayloadType.PROTO_OA_GET_TRENDBARS_RES:
                var trendbar   = ProtoOAGetTrendbarsRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                var sbTrendbar = new StringBuilder();
                foreach (var entry in trendbar.TrendbarList)
                {
                    sbTrendbar.Append("Open: " + entry.DeltaOpen + Environment.NewLine);
                    sbTrendbar.Append("High: " + entry.DeltaHigh + Environment.NewLine);
                    sbTrendbar.Append("Low: " + entry.Low + Environment.NewLine);
                    sbTrendbar.Append("Close: " + entry.DeltaClose + Environment.NewLine);
                }
                return("Trendbars{" + sbTrendbar.ToString() + "}");

            case ProtoOAPayloadType.PROTO_OA_GET_TICKDATA_REQ:
                return("GetTickDataRequest{}");

            case ProtoOAPayloadType.PROTO_OA_GET_TICKDATA_RES:
                var tickData   = ProtoOAGetTickDataRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                var sbTickData = new StringBuilder();
                foreach (var entry in tickData.TickDataList)
                {
                    sbTickData.Append("Tick: " + entry.Tick + Environment.NewLine + " " + msg.ClientMsgId);
                }
                return("Tick Data{" + sbTickData.ToString() + "}");

            case ProtoOAPayloadType.PROTO_OA_CANCEL_ORDER_REQ:
                return("CancelOrderRequest{}");

            case ProtoOAPayloadType.PROTO_OA_NEW_ORDER_REQ:
                return("CreateOrderRequest{}");

            case ProtoOAPayloadType.PROTO_OA_CLOSE_POSITION_REQ:
                return("ClosePositionRequest{}");

            case ProtoOAPayloadType.PROTO_OA_AMEND_ORDER_REQ:
                return("AmendOrderRequest{}");

            case ProtoOAPayloadType.PROTO_OA_AMEND_POSITION_SLTP_REQ:
                return("AmendPositionRequest{}");

            case ProtoOAPayloadType.PROTO_OA_SUBSCRIBE_SPOTS_REQ:
                return("SubscribeForSpotsRequest{}");

            case ProtoOAPayloadType.PROTO_OA_SUBSCRIBE_SPOTS_RES:
                return("SubscribeForSpotsResponse{}");

            case ProtoOAPayloadType.PROTO_OA_UNSUBSCRIBE_SPOTS_REQ:
                return("UnsubscribeFromSpotsRequest{}");

            case ProtoOAPayloadType.PROTO_OA_UNSUBSCRIBE_SPOTS_RES:
                return("UnsubscribeFromSpotsResponse{}");

            case ProtoOAPayloadType.PROTO_OA_SPOT_EVENT:
                var _spot_event = ProtoOASpotEvent.CreateBuilder().MergeFrom(msg.Payload).Build();
                return("SpotEvent{symbolId:" + _spot_event.SymbolId + ", bidPrice:" + (_spot_event.HasBid ? _spot_event.Bid.ToString() : "       ") + ", askPrice:" + (_spot_event.HasAsk ? _spot_event.Ask.ToString() : "       ") + "}");

            case ProtoOAPayloadType.PROTO_OA_ERROR_RES:
                var _err = ProtoOAErrorRes.CreateBuilder().MergeFrom(msg.Payload).Build();
                return("ErrorResponse{errorCode:" + _err.ErrorCode + (_err.HasDescription ? ", description:" + _err.Description : "") + "}");

            case ProtoOAPayloadType.PROTO_OA_ORDER_ERROR_EVENT:
                var _orderErr = ProtoOAOrderErrorEvent.CreateBuilder().MergeFrom(msg.Payload).Build();
                return("OrderErrorResponse{errorCode:" + _orderErr.ErrorCode + (_orderErr.HasDescription ? ", description:" + _orderErr.Description : "") + "}");

            default:
                return("unknown");
            }
        }
        // listener thread
        private void Listen(SslStream sslStream, Queue messagesQueue)
        {
            isShutdown = false;
            while (!isShutdown)
            {
                Thread.Sleep(1);

                byte[] _length   = new byte[sizeof(int)];
                int    readBytes = 0;
                do
                {
                    Thread.Sleep(0);
                    readBytes += sslStream.Read(_length, readBytes, _length.Length - readBytes);
                } while (readBytes < _length.Length);

                int length = BitConverter.ToInt32(_length.Reverse().ToArray(), 0);
                if (length <= 0)
                {
                    continue;
                }

                if (length > MaxMessageSize)
                {
                    string exceptionMsg = "Message length " + length.ToString() + " is out of range (0 - " + MaxMessageSize.ToString() + ")";
                    throw new System.IndexOutOfRangeException();
                }

                byte[] _message = new byte[length];
                readBytes = 0;
                do
                {
                    Thread.Sleep(0);
                    readBytes += sslStream.Read(_message, readBytes, _message.Length - readBytes);
                } while (readBytes < length);
                var msgFactory   = new OpenApiMessagesFactory();
                var protoMessage = msgFactory.GetMessage(_message);
                messagesQueue.Enqueue("Received: " + OpenApiMessagesPresentation.ToString(protoMessage));
                switch ((ProtoOAPayloadType)protoMessage.PayloadType)
                {
                case ProtoOAPayloadType.PROTO_OA_APPLICATION_AUTH_RES:
                    ProtoOAApplicationAuthRes Res = msgFactory.GetApplicationAuthorizationResponse(_message);
                    Console.WriteLine(Res.ToString());
                    break;

                case ProtoOAPayloadType.PROTO_OA_EXECUTION_EVENT:
                    var _payload_msg = msgFactory.GetExecutionEvent(_message);
                    if (_payload_msg.HasOrder)
                    {
                        testOrderId = _payload_msg.Order.OrderId;
                    }
                    if (_payload_msg.HasPosition)
                    {
                        testPositionId = _payload_msg.Position.PositionId;
                    }
                    break;

                case ProtoOAPayloadType.PROTO_OA_GET_ACCOUNTS_BY_ACCESS_TOKEN_RES:
                    var _accounts_list = ProtoOAGetAccountListByAccessTokenRes.CreateBuilder().MergeFrom(protoMessage.Payload).Build();
                    _accounts = _accounts_list.CtidTraderAccountList;

                    break;

                case ProtoOAPayloadType.PROTO_OA_TRADER_RES:
                    var trader = ProtoOATraderRes.CreateBuilder().MergeFrom(protoMessage.Payload).Build();
                    _traders.Add(trader.Trader);
                    break;

                case ProtoOAPayloadType.PROTO_OA_RECONCILE_RES:
                    var _reconcile_list = ProtoOAReconcileRes.CreateBuilder().MergeFrom(protoMessage.Payload).Build();
                    break;

                default:
                    break;
                }
                ;
            }
        }