Fixed websockets, updated Salimax controller code

csharp/App/Middleware/Program.cs

@@ -9,38 +9,58 @@ internal class Program
 {
     public static readonly object SharedDataLock = new object();
     
-    public static void Main(string[] args)
+    public static async Task Main(string[] args)
     {
         //For each installation id, we maintain a list of the connected clients
         var installationConnections = new Dictionary<int, InstallationInfo>();
         var installationsIds = new List<int> {1};
         var installationIps = new List<string> {"10.2.3.115"};
+        var MAX_RETRANSMISSIONS = 2;
         RabbitMqConsumer.StartRabbitMqConsumer(installationConnections,SharedDataLock);
         
         UdpClient udpClient = new UdpClient();
+        udpClient.Client.ReceiveTimeout = 2000;
         int port = 9000;
+        //Send a message to each installation and tell it to subscribe to the queue
         for (int i = 0; i < installationsIds.Count; i++)
         {
             using (udpClient)
             {
-                // Convert the message to bytes (UTF-8 encoding is used here)
+                //Try at most MAX_RETRANSMISSIONS times to reach an installation.
-                string message = "This is a message from RabbitMQ server, you can subscribe to the RabbitMQ queue";
+                for (int j = 0; j < MAX_RETRANSMISSIONS; j++)
-                byte[] data = Encoding.UTF8.GetBytes(message);
+                {
+                    string message = "This is a message from RabbitMQ server, you can subscribe to the RabbitMQ queue";
+                    byte[] data = Encoding.UTF8.GetBytes(message);
+                    udpClient.Send(data, data.Length, installationIps[i], port);
 
-                // Send the UDP message to the specified IP address and port
+                    Console.WriteLine($"Sent UDP message to {installationIps[i]}:{port}: {message}");
-                udpClient.Send(data, data.Length, installationIps[i], port);
+                    IPEndPoint remoteEndPoint = new IPEndPoint(IPAddress.Parse(installationIps[i]), port);
                     
-                Console.WriteLine($"Sent UDP message to {installationIps[i]}:{port}: {message}");
+                    try
-                IPEndPoint remoteEndPoint = new IPEndPoint(IPAddress.Parse(installationIps[i]), port);
+                    {
-                byte[] replyData = udpClient.Receive(ref remoteEndPoint);
+                        byte[] replyData = udpClient.Receive(ref remoteEndPoint);
-                string replyMessage = Encoding.UTF8.GetString(replyData);
+                        string replyMessage = Encoding.UTF8.GetString(replyData);
-                Console.WriteLine("Received message from installation "+installationsIds[i]);
+                        Console.WriteLine("Received message from installation " + installationsIds[i]);
+                        break;
+                    }
+                    catch (SocketException ex)
+                    {
+                        if (ex.SocketErrorCode == SocketError.TimedOut)
+                        {
+                            Console.WriteLine("Timed out waiting for a response. Retry...");
+                        }
+                        else
+                        {
+                            Console.WriteLine("Error: " + ex.Message);
+                        }
+                    }
+                }
             }
         }
         
-        WebSocketListener.StartServerAsync(installationConnections,SharedDataLock);
         Console.WriteLine("WebSocket server is running. Press Enter to exit.");
         
-        Console.ReadLine();
+        Console.WriteLine("WebSocket server is running. Press Enter to exit.");
+        await WebSocketListener.StartServerAsync(installationConnections,SharedDataLock);
     }
 }

csharp/App/Middleware/RabbitMQConsumer.cs

@@ -1,6 +1,5 @@
 using System.Net.WebSockets;
 using System.Text.Json;
-
 namespace InnovEnergy.App.Middleware;
 using System.Text;
 using RabbitMQ.Client;
@@ -27,14 +26,13 @@ public static class RabbitMqConsumer
         {
             var body = ea.Body.ToArray();
             var message = Encoding.UTF8.GetString(body);
-            StatusMessage receivedStatusMessage = JsonSerializer.Deserialize<StatusMessage>(message);
+            StatusMessage? receivedStatusMessage = JsonSerializer.Deserialize<StatusMessage>(message);
 
             lock (sharedDataLock)
             {
                 // Process the received message
                 if (receivedStatusMessage != null)
                 {
-                    Console.WriteLine("Received a message from installation:"+receivedStatusMessage);
                     Console.WriteLine("Received a message from installation: " + receivedStatusMessage.InstallationId + " and status is: " + receivedStatusMessage.Status);
                     Console.WriteLine("----------------------------------------------");
                     Console.WriteLine("Update installation connection table");

csharp/App/Middleware/WebSocketListener.cs

@@ -7,15 +7,13 @@ namespace InnovEnergy.App.Middleware;
 
 public static class WebSocketListener
 {
-    //For each installation id, we maintain a list of the connected clients
 
     public static async Task StartServerAsync(Dictionary<Int32, InstallationInfo> installationConnections, Object sharedDataLock)
     {
         var listener = new HttpListener();
-        listener.Prefixes.Add("http://localhost:8080/websocket/");
+        listener.Prefixes.Add("http://127.0.0.1:8080/");
-        listener.Start();
 
-        Console.WriteLine("WebSocket server listening on http://localhost:8080/websocket/");
+        listener.Start();
 
         //Http listener listens for connections. When it accepts a new connection, it creates a new Task to handle this connection
         while (true)
@@ -37,16 +35,11 @@ public static class WebSocketListener
             }
         }
 
+        //We have a task per websocket connection
         async Task HandleWebSocketConnection(WebSocket currentWebSocket, Dictionary<Int32, InstallationInfo> installationConnections)
         {
 
             var buffer = new byte[4096];
-            // Console.WriteLine("This is a new Task, the installation connections table is the following: ");
-            // foreach (var installationConnection in installationConnections)
-            // {
-            //     Console.WriteLine($"Installation ID: {installationConnection.Key}, Number of Connections: {installationConnection.Value.Count}");
-            // }
-            // Console.WriteLine("----------------------------------------------");
 
             try
             {
@@ -60,18 +53,17 @@ public static class WebSocketListener
                     
                     var message = Encoding.UTF8.GetString(buffer, 0, result.Count);
                     var installationIds = JsonSerializer.Deserialize<int[]>(message);
-                    //Console.WriteLine($"length is {installationIds.Count()}");
 
                     lock (sharedDataLock)
                     {
                         //Each front-end will send the list of the installations it wants to access
-                        //If this is a new key (installation id), initialize the list for this key and then add the websocket object of this client
+                        //If this is a new key (installation id), initialize the list for this key and then add the websocket object for this client
+                        //Then, report the status of each requested installation to the front-end that created the websocket connection
                         foreach (var installationId in installationIds)
                         {
-                            Console.WriteLine(installationId);
                             if (!installationConnections.ContainsKey(installationId))
                             {
-                                Console.WriteLine("Create new empty list for this installation id");
+                                Console.WriteLine("Create new empty list for installation id "+installationId);
                                 installationConnections[installationId] = new InstallationInfo
                                 {
                                     Status = -2
@@ -79,7 +71,6 @@ public static class WebSocketListener
                             }
 
                             installationConnections[installationId].Connections.Add(currentWebSocket);
-                            //Console.WriteLine($"ADD a new websocket, Installation ID: {installationId}, Number of Connections: {installationConnections[installationId].Count}");
 
                             var jsonObject = new
                             {
@@ -99,20 +90,17 @@ public static class WebSocketListener
                         }
 
                         Console.WriteLine("Printing installation connection list");
-                        //Print the installationConnections dictionary after inserting a websocket
                         Console.WriteLine("----------------------------------------------");
                         foreach (var installationConnection in installationConnections)
                         {
                             Console.WriteLine("Installation ID: " + installationConnection.Key + " Number of Connections: " + installationConnection.Value.Connections.Count);
                         }
-
                         Console.WriteLine("----------------------------------------------");
                     }
                 }
 
                 //When the front-end terminates the connection, the following code will be executed
                 Console.WriteLine("The connection has been terminated");
-
                 foreach (var installationConnection in installationConnections)
                 {
                     if (installationConnection.Value.Connections.Contains(currentWebSocket))

csharp/App/SaliMax/src/Program.cs

@@ -57,6 +57,7 @@ internal static class Program
     private static IConnection ?       _connection;
     private static IModel?             _channel;
     private static Boolean             _subscribedToQueue = false;
+    private static Boolean             _subscribeToQueueForTheFirstTime = false;
     private static SalimaxAlarmState   _prevSalimaxState = SalimaxAlarmState.Green;
     
     static Program()
@@ -220,6 +221,7 @@ internal static class Program
             var record = ReadStatus();
             var currentSalimaxState = GetSalimaxStateAlarm(record);
             
+            
             SendSalimaxStateAlarm(currentSalimaxState);
 
             record.ControlConstants();
@@ -258,6 +260,13 @@ internal static class Program
     {
         var s3Bucket = Config.Load().S3?.Bucket;
 
+        //When the controller boots, it tries to subscribe to the queue
+        if (_subscribeToQueueForTheFirstTime==false)
+        {
+            _subscribeToQueueForTheFirstTime = true;
+            SubscribeToQueue(currentSalimaxState, s3Bucket);
+        }
+        
         //If already subscribed to the queue and the status has been changed, update the queue
         if (_subscribedToQueue && currentSalimaxState != _prevSalimaxState)
         {
@@ -266,37 +275,34 @@ internal static class Program
                 InformMiddleware(s3Bucket, (Int32)currentSalimaxState);
         }
 
-        //If there is an available message, subscribe to the queue
+        //If there is an available message from the RabbitMQ Broker, subscribe to the queue
         if (_udpListener.Available > 0)
         {
+            IPEndPoint? serverEndpoint = null;
+        
+            var replyMessage  = "ACK";
+            var replyData     = Encoding.UTF8.GetBytes(replyMessage);
+        
+            var udpMessage = _udpListener.Receive(ref serverEndpoint);
+            var message    = Encoding.UTF8.GetString(udpMessage);
+        
+            Console.WriteLine($"Received a message: {message}");
+
+            // Send the reply to the sender's endpoint
+            _udpListener.Send(replyData, replyData.Length, serverEndpoint);
+            Console.WriteLine($"Replied to {serverEndpoint}: {replyMessage}");
+            
             SubscribeToQueue(currentSalimaxState, s3Bucket);
         }
     }
 
     private static void SubscribeToQueue(SalimaxAlarmState currentSalimaxState, String? s3Bucket)
     {
-        IPEndPoint? serverEndpoint = null;
-        
-        var replyMessage  = "ACK";
-        var replyData     = Encoding.UTF8.GetBytes(replyMessage);
-        
-        var udpMessage = _udpListener.Receive(ref serverEndpoint);
-        var message    = Encoding.UTF8.GetString(udpMessage);
-        
-        Console.WriteLine($"Received a message: {message}");
-
-        // Send the reply to the sender's endpoint
-        _udpListener.Send(replyData, replyData.Length, serverEndpoint);
-        Console.WriteLine($"Replied to {serverEndpoint}: {replyMessage}");
-
         _factory    = new ConnectionFactory { HostName = VpnServerIp };
         _connection = _factory.CreateConnection();
         _channel    = _connection.CreateModel();
-        
         _channel.QueueDeclare(queue: "statusQueue", durable: false, exclusive: false, autoDelete: false, arguments: null);
-                
         Console.WriteLine("The controller sends its status to the middleware for the first time");
-        
         if (s3Bucket != null) InformMiddleware(s3Bucket, (Int32)currentSalimaxState);
         
         _subscribedToQueue = true;