// State object for receiving data from remote device.
    public class StateObject : EventArgs
    {
        // Client socket.
        public Socket workSocket = null;
        // Size of receive buffer.
        public const int BufferSize = 512;
        // Receive buffer.
        public byte[] buffer = new byte[BufferSize];
        // Received data string.
        public StringBuilder sb = new StringBuilder();
    }
    public class SocketClass:ISocket
    {
        // ManualResetEvent instances signal completion.
        private ManualResetEvent connectDone =
            new ManualResetEvent(false);
        private ManualResetEvent sendDone =
            new ManualResetEvent(false);
        private ManualResetEvent receiveDone =
            new ManualResetEvent(false);

        public delegate void HandlerMessage(object ob, StateObject args);
        public event HandlerMessage ReciveMessage;

        private static Socket client;

        private string serverName;
        private int port;
        private string nickName;
        private string userName;
        private string botPrefixName;
        public SocketClass(IBotInfo info)
        {
            serverName = info.Servername;
            nickName = info.Nickname;
            userName = info.Username;
            port = info.Port;
            botPrefixName = info.BotPrefixName;
        }
        public SocketClass()
        {
        }

        public void StartClient()
        {
            // need for encoding win-1251!!!!
            Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);

            try
            {
                // Connect to a remote device.
                IPHostEntry ipHostInfo = Dns.GetHostEntry(serverName);
                IPAddress ipAddress = ipHostInfo.AddressList[0];
                IPEndPoint remoteEP = new IPEndPoint(ipAddress, port);

                // Create a TCP/IP socket.
                client = new Socket(ipAddress.AddressFamily,
                  SocketType.Stream, ProtocolType.Tcp);

                // Connect to the remote endpoint.
                client.BeginConnect(remoteEP,
                    new AsyncCallback(ConnectCallback), client);
                connectDone.WaitOne();

                // Send test data to the remote device.
                Send(client, $"NICK {nickName}");

                Send(client, $"USER {userName}");

                sendDone.WaitOne();

                // Receive the response from the remote device.
                Receive(client);

                receiveDone.WaitOne();


                int q = 1;
                // System.IO.File.WriteAllText("WriteText.txt", response);
                // Release the socket.
                //client.Shutdown(SocketShutdown.Both);
                //client.Close();

            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }
        private void ConnectCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket client = (Socket)ar.AsyncState;

                // Complete the connection.
                client.EndConnect(ar);

                Console.WriteLine("Socket connected to {0}",
                    client.RemoteEndPoint.ToString());

                // Signal that the connection has been made.
                connectDone.Set();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }
        private void Receive(Socket client)
        {
            try
            {
                StateObject state = new StateObject();
                state.workSocket = client;

                // Begin receiving the data from the remote device.
                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }
        private void ReceiveCallback(IAsyncResult ar)
        {
            String content = String.Empty;

            // Retrieve the state object and the handler socket
            // from the asynchronous state object.
            StateObject state = (StateObject)ar.AsyncState;
            Socket handler = state.workSocket;

            // Read data from the client socket.
            int bytesRead = handler.EndReceive(ar);

            if (bytesRead > 0)
            {
                // convert received msg to win-1251 !!!!
                state.sb.Append(Encoding.GetEncoding("Windows-1251").GetString(
                    state.buffer, 0, bytesRead));

                content = state.sb.ToString();

                // broadcast message if match exactly prefix and name of bot.
                //if (Regex.IsMatch(content, $@":({botPrefixName}) "))
                //    OnReciveMessage(this, state);

                // broadcast message if match exactly the commands.
                if (MenuCommand.commands.Any(f => content.Contains(f)))
                {
                    OnReciveMessage(this, state);

                }

                if (content.Contains("#dev"))
                {
                    BotDBContext botDbContext = new BotDBContext();

                    LogMessages logMessages = new LogMessages();
                     logMessages.Channel = "#dev";
                     logMessages.DateTime = DateTime.Now;
                     logMessages.NickName = Regex.Match(content, @":(.+?)!").Groups[1].Value;
                    logMessages.Message = Regex.Match(content, @".:(.+)\r\n").Groups[1].Value;


                    botDbContext.Add(logMessages);
                    botDbContext.SaveChanges();
                }

                if (content.Contains("PING"))
                {
                    Send(handler, $"PONG ");
                    sendDone.Set();
                }

                System.IO.File.WriteAllText(@"BotLog.txt", content);
                // Check for end-of-file tag. If it is not there, read
                // more data.
                if (content.IndexOf("\r\n", StringComparison.Ordinal) > -1)
                {
                    Console.WriteLine("Read {0} bytes from socket. \n Data : {1}", content.Length, content);
                    state.sb.Clear();
                    receiveDone.Set();
                }

                // Not all data received. Get more.
                handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);

            }
        }


        public void Send(string msg)
        {
            Send(client, msg);
        }
        private void Send(Socket client, String data)
        {

            // convert encoding to Windows-1251 and at last line set \r\n
            byte[] byteData = Encoding.GetEncoding("Windows-1251").GetBytes(data + "\r\n");

            // Begin sending the data to the remote device.

            client.BeginSend(byteData, 0, byteData.Length, 0,
                new AsyncCallback(SendCallback), client);
        }
        private void SendCallback(IAsyncResult ar)
        {
            try
            {
                // Retrieve the socket from the state object.
                Socket client = (Socket)ar.AsyncState;

                // Complete sending the data to the remote device.
                int bytesSent = client.EndSend(ar);
                Console.WriteLine("Sent {0} bytes to server.", bytesSent);

                // Signal that all bytes have been sent.
                sendDone.Set();
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }
        }

        protected virtual void OnReciveMessage(object ob, StateObject args)
        {
            if (ReciveMessage != null)
                ReciveMessage?.Invoke(ob, args);
        }



    }