From 1b171265452f4552ffc7e1bdeee15152d3b3474e Mon Sep 17 00:00:00 2001
From: Benedikt Schenkel <Benedikt.Schenkel@systemslab21.com>
Date: Fri, 24 Nov 2023 11:44:23 +0100
Subject: [PATCH] refactor

---
 src/Point/Point.cs                            | 16 ++---
 .../PointToInterlockingConnectionB4R1Impl.cs  | 63 ++++++++++---------
 2 files changed, 41 insertions(+), 38 deletions(-)

diff --git a/src/Point/Point.cs b/src/Point/Point.cs
index d45f7d2..0ef1131 100644
--- a/src/Point/Point.cs
+++ b/src/Point/Point.cs
@@ -1,17 +1,13 @@
-using System.Net.WebSockets;
-using System.Text.Json;
-using Google.Protobuf;
-using Grpc.Core;
-using Sci;
+using DegradedPointPosition = EulynxLive.Messages.IPointToInterlockingConnection.IPointToInterlockingConnection.DegradedPointPosition;
 using EulynxLive.Messages.IPointToInterlockingConnection;
+using EulynxLive.Point.Proto;
+using Grpc.Core;
 using PointPosition = EulynxLive.Messages.IPointToInterlockingConnection.IPointToInterlockingConnection.PointPosition;
-using DegradedPointPosition = EulynxLive.Messages.IPointToInterlockingConnection.IPointToInterlockingConnection.DegradedPointPosition;
 using PointState = EulynxLive.Messages.IPointToInterlockingConnection.IPointToInterlockingConnection.PointState;
-using static Sci.Rasta;
+using Sci;
+using System.Net.WebSockets;
 using System.Text;
-using Grpc.Net.Client;
-using EulynxLive.Point.Components;
-using EulynxLive.Point.Proto;
+using System.Text.Json;
 
 namespace EulynxLive.Point
 {
diff --git a/src/Point/PointToInterlockingConnectionB4R1Impl.cs b/src/Point/PointToInterlockingConnectionB4R1Impl.cs
index d90fb56..326916b 100644
--- a/src/Point/PointToInterlockingConnectionB4R1Impl.cs
+++ b/src/Point/PointToInterlockingConnectionB4R1Impl.cs
@@ -1,4 +1,3 @@
-using System.Net.WebSockets;
 using EulynxLive.Messages.Baseline4R1;
 using EulynxLive.Point;
 using Google.Protobuf;
@@ -48,32 +47,30 @@ public void Connect()
     public async Task<bool> InitializeConnection(PointState state)
     {
         _logger.LogTrace("Connected. Waiting for request...");
-        if (!await _currentConnection.ResponseStream.MoveNext(_timeout.Token)
-            || Message.FromBytes(_currentConnection.ResponseStream.Current.Message.ToByteArray()) is not PointPdiVersionCheckCommand)
+        if (await ReceiveMessage<PointPdiVersionCheckCommand>() == null)
         {
             _logger.LogError("Unexpected message.");
             return false;
         }
 
         var versionCheckResponse = new PointPdiVersionCheckMessage(_localId, _remoteId, PointPdiVersionCheckMessageResultPdiVersionCheck.PDIVersionsFromReceiverAndSenderDoMatch, /* TODO */ 0, 0, new byte[] { });
-        await _currentConnection.RequestStream.WriteAsync(new SciPacket() { Message = ByteString.CopyFrom(versionCheckResponse.ToByteArray()) });
+        await SendMessage(versionCheckResponse);
 
-        if (!await _currentConnection.ResponseStream.MoveNext(_timeout.Token)
-            || Message.FromBytes(_currentConnection.ResponseStream.Current.Message.ToByteArray()) is not PointInitialisationRequestCommand)
+        if (await ReceiveMessage<PointInitialisationRequestCommand>() == null)
         {
             _logger.LogError("Unexpected message.");
             return false;
         }
 
         var startInitialization = new PointStartInitialisationMessage(_localId, _remoteId);
-        await _currentConnection.RequestStream.WriteAsync(new SciPacket() { Message = ByteString.CopyFrom(startInitialization.ToByteArray()) });
+        await SendMessage(startInitialization);
 
         var pointState = new B4R1PointStateImpl(state);
         var initialPosition = new PointPointPositionMessage(_localId, _remoteId, pointState.PointPosition, pointState.DegradedPointPosition);
-        await _currentConnection.RequestStream.WriteAsync(new SciPacket() { Message = ByteString.CopyFrom(initialPosition.ToByteArray()) });
+        await SendMessage(initialPosition);
 
         var completeInitialization = new PointInitialisationCompletedMessage(_localId, _remoteId);
-        await _currentConnection.RequestStream.WriteAsync(new SciPacket() { Message = ByteString.CopyFrom(completeInitialization.ToByteArray()) });
+        await SendMessage(completeInitialization);
         return true;
     }
 
@@ -81,41 +78,50 @@ public async Task SendPointPosition(PointState state)
     {
         var pointState = new B4R1PointStateImpl(state);
         var response = new PointPointPositionMessage(_localId, _remoteId, pointState.PointPosition, pointState.DegradedPointPosition);
-        await _currentConnection.RequestStream.WriteAsync(new SciPacket() { Message = ByteString.CopyFrom(response.ToByteArray()) });
+        await SendMessage(response);
     }
 
     async public Task SendTimeoutMessage()
     {
         var response = new PointTimeoutMessage(_localId, _remoteId);
-        await _currentConnection.RequestStream.WriteAsync(new SciPacket() { Message = ByteString.CopyFrom(response.ToByteArray()) });
+        await SendMessage(response);
     }
 
     public async Task<PointPosition?> ReceivePointPosition()
     {
+        var message = await ReceiveMessage<PointMovePointCommand>();
 
-        if (!await _currentConnection.ResponseStream.MoveNext())
+        return (message != null)? message.CommandedPointPosition switch
         {
-            return null;
-        }
-        var message = Message.FromBytes(_currentConnection.ResponseStream.Current.Message.ToByteArray());
-
-        if (message is PointMovePointCommand movePointCommand)
-        {
-            return movePointCommand.CommandedPointPosition switch
-            {
-                PointMovePointCommandCommandedPointPosition.SubsystemElectronicInterlockingRequestsARightHandPointMoving => PointPosition.RIGHT,
-                PointMovePointCommandCommandedPointPosition.SubsystemElectronicInterlockingRequestsALeftHandPointMoving => PointPosition.LEFT,
-            };
-        }
-        
-        _logger.LogInformation("Received unknown message {}", message.GetType());
-        return null;
+            PointMovePointCommandCommandedPointPosition.SubsystemElectronicInterlockingRequestsARightHandPointMoving => PointPosition.RIGHT,
+            PointMovePointCommandCommandedPointPosition.SubsystemElectronicInterlockingRequestsALeftHandPointMoving => PointPosition.LEFT,
+        } : null;
     }
 
     public void Dispose()
     {
         _currentConnection?.Dispose();
     }
+
+    private async Task SendMessage(Message message)
+    {
+        if (_currentConnection == null) throw new NullReferenceException("Connection is null. Did you call Connect()?");
+        await _currentConnection.RequestStream.WriteAsync(new SciPacket() { Message = ByteString.CopyFrom(message.ToByteArray()) });
+    }
+
+    private async Task<T?> ReceiveMessage<T>() where T : Message
+    {
+        if (_currentConnection == null) throw new NullReferenceException("Connection is null. Did you call Connect()?");
+        if (!await _currentConnection.ResponseStream.MoveNext(_timeout.Token)) return null;
+        
+        var message = Message.FromBytes(_currentConnection.ResponseStream.Current.Message.ToByteArray());
+        if (message is not T)
+        {
+            _logger.LogError("Unexpected message: {}", message);
+            return null;
+        }
+        return message as T;
+    }
 }
 
 public class B4R1PointStateImpl
@@ -124,7 +130,8 @@ public class B4R1PointStateImpl
     public PointPointPositionMessageReportedPointPosition PointPosition { get => map(_state.PointPosition); }
     public PointPointPositionMessageReportedDegradedPointPosition DegradedPointPosition { get => map(_state.DegradedPointPosition); }
 
-    public B4R1PointStateImpl(PointState state){
+    public B4R1PointStateImpl(PointState state)
+    {
         _state = state;
     }