Refactor shutdown service

src/KFlearning.Core/Services/RemoteShutdownServer.cs

@@ -0,0 +1,101 @@
+// SOLUTION : KFlearning
+// PROJECT  : KFlearning.Core
+// FILENAME : RemoteServer.cs
+// AUTHOR   : Fahmi Noor Fiqri, Kodesiana.com
+// WEBSITE  : https://kodesiana.com
+// REPO     : https://github.com/Kodesiana or https://github.com/fahminlb33
+// 
+// This file is part of KFlearning, see LICENSE.
+// See this code in repository URL above!
+
+using System;
+using System.IO;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+
+namespace KFlearning.Core.Services
+{
+    public interface IRemoteShutdownServer : IDisposable
+    {
+        void Listen();
+        void SendShutdown(string cluster);
+
+        event EventHandler<ShutdownRequestedEventArgs> ShutdownRequested;
+    }
+
+    public class RemoteShutdownServer : IRemoteShutdownServer
+    {
+        public const int ServicePort = 2021;
+        private const string MessageShutdown = "SDWN";
+
+        private static readonly IPEndPoint ServiceEndpoint = new IPEndPoint(IPAddress.Any, ServicePort);
+
+        private readonly UdpClient _socket = new UdpClient();
+        private MemoryStream _uploadStream;
+
+        public event EventHandler<ShutdownRequestedEventArgs> ShutdownRequested;
+        public event EventHandler<ShutdownRequestedEventArgs> FileBroadcast;
+
+        public RemoteShutdownServer()
+        {
+            _socket.Client.Bind(ServiceEndpoint);
+        }
+
+        #region Public Methods
+
+        public void Listen()
+        {
+            _socket.BeginReceive(ReceiveCallback, null);
+        }
+
+        public void SendShutdown(string cluster)
+        {
+            Send(MessageShutdown, cluster);
+        }
+
+        #endregion
+
+        #region Private Methods (Callbacks)
+
+        private void Send(string message, string body)
+        {
+            var data = Encoding.ASCII.GetBytes($"{message}|{body}");
+            _socket.BeginSend(data, data.Length, ServiceEndpoint, SendCallback, null);
+        }
+
+        private void SendCallback(IAsyncResult ar)
+        {
+            _socket.EndSend(ar);
+        }
+
+        private void ReceiveCallback(IAsyncResult ar)
+        {
+            var epFrom = new IPEndPoint(IPAddress.Any, ServicePort);
+            var bytes = _socket.EndReceive(ar, ref epFrom);
+            var message = Encoding.ASCII.GetString(bytes);
+            ProcessMessage(message, epFrom.Address);
+
+            _socket.BeginReceive(ReceiveCallback, null);
+        }
+
+        private void ProcessMessage(string message, IPAddress server)
+        {
+            if (!message.StartsWith(MessageShutdown)) return;
+            var cluster = message.Split('|')[1];
+            ShutdownRequested?.Invoke(this, new ShutdownRequestedEventArgs { Address = server, Clusster = cluster });
+        }
+
+        #endregion
+
+        #region IDisposable
+
+        public void Dispose()
+        {
+            ((IDisposable)_socket)?.Dispose();
+            ((IDisposable)_uploadStream)?.Dispose();
+        } 
+
+        #endregion
+    }
+}

src/KFlearning.Core/Services/RemoteEventArgs.cs → src/KFlearning.Core/Services/ShutdownRequestedEventArgs.cs

@@ -13,8 +13,9 @@
 
 namespace KFlearning.Core.Services
 {
-    public class RemoteEventArgs : EventArgs
+    public class ShutdownRequestedEventArgs : EventArgs
     {
         public IPAddress Address { get; set; }
+        public string Clusster { get; set; }
     }
 }