Add Middleware functionality, add middleware connection to the controller

csharp/App/Middleware/InstallationInfo.cs

@@ -0,0 +1,9 @@
+using System.Net.WebSockets;
+
+namespace InnovEnergy.App.Middleware;
+
+public class InstallationInfo
+{
+    public int Status { get; set; }
+    public List<WebSocket> Connections { get; } = new List<WebSocket>();
+}

csharp/App/Middleware/Middleware.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+<Import Project="../InnovEnergy.App.props" />
+
+<PropertyGroup>
+    <RootNamespace>InnovEnergy.App.Middleware</RootNamespace>
+</PropertyGroup>
+
+<ItemGroup>
+  <PackageReference Include="RabbitMQ.Client" Version="6.6.0" />
+</ItemGroup>
+
+<ItemGroup>
+  <ProjectReference Include="..\..\Lib\Utils\Utils.csproj" />
+</ItemGroup>
+    
+
+</Project>

csharp/App/Middleware/Program.cs

@@ -0,0 +1,46 @@
+using InnovEnergy.App.Middleware;
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Net.WebSockets;
+using System.Text;
+
+internal class Program
+{
+    public static readonly object SharedDataLock = new object();
+    
+    public static void 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"};
+        RabbitMqConsumer.StartRabbitMqConsumer(installationConnections,SharedDataLock);
+
+        UdpClient udpClient = new UdpClient();
+        int port = 9000;
+        for (int i = 0; i < installationsIds.Count; i++)
+        {
+            using (udpClient)
+            {
+                // Convert the message to bytes (UTF-8 encoding is used here)
+                string message = "This is a message from RabbitMQ server, you can subscribe to the RabbitMQ queue";
+                byte[] data = Encoding.UTF8.GetBytes(message);
+
+                // Send the UDP message to the specified IP address and port
+                udpClient.Send(data, data.Length, installationIps[i], port);
+
+                Console.WriteLine($"Sent UDP message to {installationIps[i]}:{port}: {message}");
+                IPEndPoint remoteEndPoint = new IPEndPoint(IPAddress.Parse(installationIps[i]), port);
+                byte[] replyData = udpClient.Receive(ref remoteEndPoint);
+                string replyMessage = Encoding.UTF8.GetString(replyData);
+                Console.WriteLine("Received message from installation "+installationsIds[i]);
+            }
+        }
+        
+        WebSocketListener.StartServerAsync(installationConnections,SharedDataLock);
+        Console.WriteLine("WebSocket server is running. Press Enter to exit.");
+        
+        Console.ReadLine();
+    }
+}

csharp/App/Middleware/RabbitMQConsumer.cs

@@ -0,0 +1,87 @@
+using System.Net.WebSockets;
+using System.Text.Json;
+
+namespace InnovEnergy.App.Middleware;
+using System.Text;
+using RabbitMQ.Client;
+using RabbitMQ.Client.Events;
+
+public static class RabbitMqConsumer
+{
+    
+    private static ConnectionFactory _factory = null!;
+    private static IConnection _connection = null!;
+    private static IModel _channel= null!;
+
+    public static void StartRabbitMqConsumer(Dictionary<Int32, InstallationInfo> installationConnections, Object sharedDataLock)
+    {
+        string vpnServerIp = "10.2.0.11";
+        _factory = new ConnectionFactory { HostName = vpnServerIp };
+        _connection = _factory.CreateConnection();
+        _channel = _connection.CreateModel();
+        Console.WriteLine("Middleware subscribed to RabbitMQ queue, ready for receiving messages");
+        _channel.QueueDeclare(queue: "statusQueue", durable: false, exclusive: false, autoDelete: false, arguments: null);
+
+        var consumer = new EventingBasicConsumer(_channel);
+        consumer.Received += (model, ea) =>
+        {
+            var body = ea.Body.ToArray();
+            var message = Encoding.UTF8.GetString(body);
+            StatusMessage receivedStatusMessage = JsonSerializer.Deserialize<StatusMessage>(message);
+
+            lock (sharedDataLock)
+            {
+                // Process the received message
+                if (receivedStatusMessage != null)
+                {
+                    Console.WriteLine("Received a message from installation: " + receivedStatusMessage.InstallationId + " and status is: " + receivedStatusMessage.Status);
+                    Console.WriteLine("----------------------------------------------");
+                    Console.WriteLine("Update installation connection table");
+                    var installationId = receivedStatusMessage.InstallationId;
+
+                    if (!installationConnections.ContainsKey(installationId))
+                    {
+                        Console.WriteLine("Create new empty list for installation: " + installationId);
+                        installationConnections[installationId] = new InstallationInfo
+                        {
+                            Status = receivedStatusMessage.Status
+                        };
+                    }
+
+                    Console.WriteLine("----------------------------------------------");
+
+                    foreach (var installationConnection in installationConnections)
+                    {
+                        if (installationConnection.Key == installationId && installationConnection.Value.Connections.Count > 0)
+                        {
+                            Console.WriteLine("Update all the connected websockets for installation " + installationId);
+                            installationConnection.Value.Status = receivedStatusMessage.Status;
+
+                            var jsonObject = new
+                            {
+                                id = installationId,
+                                status = receivedStatusMessage.Status
+                            };
+
+                            string jsonString = JsonSerializer.Serialize(jsonObject);
+                            byte[] dataToSend = Encoding.UTF8.GetBytes(jsonString);
+
+                            foreach (var connection in installationConnection.Value.Connections)
+                            {
+                                connection.SendAsync(
+                                    new ArraySegment<byte>(dataToSend, 0, dataToSend.Length),
+                                    WebSocketMessageType.Text,
+                                    true, // Indicates that this is the end of the message
+                                    CancellationToken.None
+                                );
+                            }
+                        }
+                    }
+                }
+            }
+        };
+
+        _channel.BasicConsume(queue: "statusQueue", autoAck: true, consumer: consumer);
+        
+    }
+}

csharp/App/Middleware/StatusMessage.cs

@@ -0,0 +1,8 @@
+
+namespace InnovEnergy.App.Middleware;
+
+public class StatusMessage
+{
+    public required int InstallationId { get; init; }
+    public required int Status         { get; init; }
+}

csharp/App/Middleware/WebSocketListener.cs

@@ -0,0 +1,141 @@
+using System.Net;
+using System.Net.WebSockets;
+using System.Text;
+using System.Text.Json;
+
+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.Start();
+
+        Console.WriteLine("WebSocket server listening on http://localhost:8080/websocket/");
+
+        //Http listener listens for connections. When it accepts a new connection, it creates a new Task to handle this connection
+        while (true)
+        {
+            var context = await listener.GetContextAsync();
+            if (context.Request.IsWebSocketRequest)
+            {
+                var webSocketContext = await context.AcceptWebSocketAsync(null);
+                var webSocket = webSocketContext.WebSocket;
+
+                // Add the connected WebSocket to the collection
+                Console.WriteLine("Accepted a new websocket connection");
+                HandleWebSocketConnection(webSocket, installationConnections);
+            }
+            else
+            {
+                context.Response.StatusCode = 400;
+                context.Response.Close();
+            }
+        }
+
+        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($"Installation ID: {installationConnection.Key}, Number of Connections: {installationConnection.Value.Count}");
+            // }
+            // Console.WriteLine("----------------------------------------------");
+
+            try
+            {
+                while (currentWebSocket.State == WebSocketState.Open)
+                {
+                    //Listen for incoming messages on this WebSocket
+                    var result = await currentWebSocket.ReceiveAsync(buffer, CancellationToken.None);
+                    Console.WriteLine("Received a new message from websocket");
+                    if (result.MessageType != WebSocketMessageType.Text)
+                        continue;
+                    
+                    var message = Encoding.UTF8.GetString(buffer, 0, result.Count);
+                    var installationIds = JsonSerializer.Deserialize<int[]>(message);
+                    //Console.WriteLine($"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
+                        foreach (var installationId in installationIds)
+                        {
+                            Console.WriteLine(installationId);
+                            if (!installationConnections.ContainsKey(installationId))
+                            {
+                                Console.WriteLine("Create new empty list for this installation id");
+                                installationConnections[installationId] = new InstallationInfo
+                                {
+                                    Status = -2
+                                };
+                            }
+
+                            installationConnections[installationId].Connections.Add(currentWebSocket);
+                            //Console.WriteLine($"ADD a new websocket, Installation ID: {installationId}, Number of Connections: {installationConnections[installationId].Count}");
+
+                            var jsonObject = new
+                            {
+                                id = installationId,
+                                status = installationConnections[installationId].Status
+                            };
+
+                            var jsonString = JsonSerializer.Serialize(jsonObject);
+                            var dataToSend = Encoding.UTF8.GetBytes(jsonString);
+
+
+                            currentWebSocket.SendAsync(dataToSend,
+                                WebSocketMessageType.Text,
+                                true, // Indicates that this is the end of the message
+                                CancellationToken.None
+                            );
+                        }
+
+                        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))
+                    {
+                        installationConnection.Value.Connections.Remove(currentWebSocket);
+                    }
+                }
+
+                await currentWebSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "Connection closed by server", CancellationToken.None);
+                //Print the installationConnections dictionary after deleting a websocket
+                Console.WriteLine("Print the installation connections list after deleting a websocket");
+                Console.WriteLine("----------------------------------------------");
+                foreach (var installationConnection in installationConnections)
+                {
+                    Console.WriteLine("Installation ID: "+ installationConnection.Key+" Number of Connections: "+installationConnection.Value.Connections.Count);
+                }
+                Console.WriteLine("----------------------------------------------");
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine("WebSocket error: " + ex.Message);
+            }
+        }
+    }
+}
+

csharp/App/SaliMax/SaliMax.csproj

@@ -8,6 +8,7 @@
     <ItemGroup>
         <PackageReference Version="3.2.4" Include="Flurl.Http" />
         <PackageReference Version="7.0.0" Include="Microsoft.Extensions.Logging" />
+        <PackageReference Include="RabbitMQ.Client" Version="6.6.0" />
     </ItemGroup>
 
     <ItemGroup>

csharp/App/SaliMax/src/MiddlewareClasses/StatusMessage.cs

@@ -0,0 +1,8 @@
+
+namespace InnovEnergy.App.SaliMax.MiddlewareClasses;
+
+public class StatusMessage
+{
+    public required int InstallationId { get; init; }
+    public required int Status         { get; init; }
+}

csharp/App/SaliMax/src/Program.cs

@@ -1,8 +1,13 @@
+using System.Net;
+using System.Net.NetworkInformation;
+using System.Net.Sockets;
 using System.Reactive.Linq;
 using System.Reactive.Threading.Tasks;
+using System.Text;
 using Flurl.Http;
 using InnovEnergy.App.SaliMax.Devices;
 using InnovEnergy.App.SaliMax.Ess;
+using InnovEnergy.App.SaliMax.MiddlewareClasses;
 using InnovEnergy.App.SaliMax.SaliMaxRelays;
 using InnovEnergy.App.SaliMax.System;
 using InnovEnergy.App.SaliMax.SystemConfig;
@@ -18,6 +23,8 @@ using InnovEnergy.Lib.Devices.Trumpf.TruConvertDc.Control;
 using InnovEnergy.Lib.Protocols.Modbus.Channels;
 using InnovEnergy.Lib.Units;
 using InnovEnergy.Lib.Utils;
+using System.Text.Json;
+using RabbitMQ.Client;
 using static InnovEnergy.Lib.Devices.Trumpf.SystemControl.DataTypes.SystemConfig;
 using DeviceState = InnovEnergy.App.SaliMax.Devices.DeviceState;
 
@@ -29,7 +36,6 @@ namespace InnovEnergy.App.SaliMax;
 internal static class Program
 {
     private static readonly TimeSpan UpdateInterval = TimeSpan.FromSeconds(2);
-    
     private static readonly IReadOnlyList<Byte> BatteryNodes;
     
     private static readonly Channel TruConvertAcChannel ;
@@ -41,6 +47,15 @@ internal static class Program
     private static readonly Channel PvOnAcIsland        ;
     private static readonly Channel RelaysChannel       ;
     private static readonly Channel BatteriesChannel    ;
+
+    private static IPAddress _controllerIpAddress;
+    private static UdpClient _udpListener;
+    private const string VpnServerIp = "10.2.0.11";
+    private static ConnectionFactory? _factory ;
+    private static IConnection ?_connection;
+    private static IModel? _channel;
+    private static bool _subscribedToQueue = false;
+    private static SalimaxAlarmState _prevSalimaxState = SalimaxAlarmState.Orange;
     
     static Program()
     {
@@ -70,6 +85,22 @@ internal static class Program
 
     public static async Task Main(String[] args)
     {
+
+        _controllerIpAddress=FindVpnIp();
+        if (_controllerIpAddress == null)
+        {
+            Console.WriteLine("There is no VPN interface, exiting...");
+            return;
+        }
+        
+        
+        int udpPort = 9000;
+        IPEndPoint endPoint = new IPEndPoint(_controllerIpAddress, udpPort);
+        
+        _udpListener = new UdpClient();
+        _udpListener.Client.Blocking = false;
+        _udpListener.Client.Bind(endPoint);
+        
         while (true)
         {
             //CreateAverage();
@@ -149,7 +180,6 @@ internal static class Program
                 LoadOnAcGrid     = gridBusLoad,
                 LoadOnAcIsland   = loadOnAcIsland,
                 LoadOnDc         = dcLoad,
-
                 StateMachine     = StateMachine.Default,
                 EssControl       = EssControl.Default,
                 Log              = new SystemLog { SalimaxAlarmState = SalimaxAlarmState.Green, Message = null }, //TODO: Put real stuff
@@ -183,9 +213,24 @@ internal static class Program
         {
             Watchdog.NotifyAlive();
 
-            var record = ReadStatus();           
+            var record = ReadStatus();
-          
+            var currentSalimaxState = GetSalimaxStateAlarm(record);
-            var salimaxAlarmsState = GetSalimaxStateAlarm(record);
+            
+            //--------------------------------------------------------------------------------------------
+            //If already subscribed to the queue and the status has been changed, update the queue
+            if (_subscribedToQueue && currentSalimaxState != _prevSalimaxState)
+            {
+                _prevSalimaxState = currentSalimaxState;
+                InformMiddleware(Config.Load().S3.Bucket, (int)currentSalimaxState);
+            }
+            
+            //If there is an available message, subscribe to the queue
+            if (_udpListener.Available > 0)
+            {
+                subscribedToQueue(currentSalimaxState);
+            }
+            //--------------------------------------------------------------------------------------------
+
             
             record.ControlConstants();
             record.ControlSystemState();
@@ -219,6 +264,73 @@ internal static class Program
         // ReSharper disable once FunctionNeverReturns
     }
 
+    private static void subscribedToQueue(SalimaxAlarmState currentSalimaxState)
+    {
+        IPEndPoint serverEndpoint = null;
+        byte[] udpMessage = _udpListener.Receive(ref serverEndpoint);
+
+        string message = Encoding.UTF8.GetString(udpMessage);
+        Console.WriteLine($"Received a message: {message}");
+
+        string replyMessage = "ACK";
+        byte[] replyData = Encoding.UTF8.GetBytes(replyMessage);
+
+        // Send the reply to the sender's endpoint
+        _udpListener.Send(replyData, replyData.Length, serverEndpoint);
+        Console.WriteLine($"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");
+        InformMiddleware(Config.Load().S3.Bucket, (int)currentSalimaxState);
+        _subscribedToQueue = true;
+    }
+
+    private static IPAddress FindVpnIp()
+    {
+        string interfaceName = "innovenergy";
+        IPAddress controllerIpAddress = null;
+
+        NetworkInterface[] networkInterfaces = NetworkInterface.GetAllNetworkInterfaces();
+        foreach (NetworkInterface networkInterface in networkInterfaces)
+        {
+            if (networkInterface.Name == interfaceName)
+            {
+                IPInterfaceProperties ipProps = networkInterface.GetIPProperties();
+                UnicastIPAddressInformationCollection unicastIPs = ipProps.UnicastAddresses;
+                Console.WriteLine("VPN IP is: "+unicastIPs[0].Address);
+                controllerIpAddress = unicastIPs[0].Address;
+                break;
+            }
+        }
+
+        return (controllerIpAddress);
+    }
+
+    private static void  InformMiddleware(string bucket, int status)
+    {
+        int.TryParse(bucket[0].ToString(), out var installationId);
+        
+        var jsonObject = new StatusMessage
+        {
+            InstallationId = installationId,
+            Status = status
+        };
+        
+        var message = JsonSerializer.Serialize(jsonObject);
+        var body = Encoding.UTF8.GetBytes(message);
+
+        _channel.BasicPublish(exchange: string.Empty,
+            routingKey: "statusQueue",
+            basicProperties: null,
+            body: body);
+        Console.WriteLine($"Producer sent message: {message}");
+        
+    }
+
     private static SalimaxAlarmState GetSalimaxStateAlarm(StatusRecord record)
     {
        var alarmCondition = record.DetectAlarmStates();