using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading.Tasks;

namespace Time_Server
{
    class Program
    {
        private static byte[] _buffer = new byte[1024];
        private static List<Socket> _clientSockets = new List<Socket>();
        private static Socket _serverSocket = new Socket
            (AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
        static void Main(string[] args)
        {
            Console.Title = "Server";
            SetupServer();
            Console.ReadLine();

        }
        private static void SetupServer()
        {
            Console.WriteLine("[ " + DateTime.Now.ToString() + "] Serveris ijungtas");
            _serverSocket.Bind(new IPEndPoint(IPAddress.Any, 100));
            _serverSocket.Listen(1);
            _serverSocket.BeginAccept(new AsyncCallback(AccepCallback), null);

        }

        private static void AccepCallback(IAsyncResult AR)
        {
            Socket socket = _serverSocket.EndAccept(AR);
            _clientSockets.Add(socket);
            string clientIP = socket.RemoteEndPoint.ToString();
            Console.WriteLine("[ " + DateTime.Now.ToString() + "] Klientas prisijunge [ " + clientIP + " ]\n");
            socket.BeginReceive(_buffer, 0, _buffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), socket);
            _serverSocket.BeginAccept(new AsyncCallback(AccepCallback), null);
        }
        private static void ReceiveCallback(IAsyncResult AR)
        {
            try
            {
                Socket socket = (Socket)AR.AsyncState;
                int received = socket.EndReceive(AR);
                byte[] dataBuf = new byte[received];
                Array.Copy(_buffer, dataBuf, received);

                string text = Encoding.ASCII.GetString(dataBuf);
                string clientIP = socket.RemoteEndPoint.ToString();
                Console.Write("[ " + DateTime.Now.ToString() + "] Gauta uzklausa is kliento ( " + clientIP + " ): " + text + "\n");

                string response = string.Empty;

                response = "Serveris gavo tavo uzklausa";

                byte[] data = Encoding.ASCII.GetBytes(response);
                socket.BeginSend(data, 0, data.Length, SocketFlags.None, new AsyncCallback(SendCallback), socket);
            }
            catch (Exception)
            {

                Console.WriteLine("[ " + DateTime.Now.ToString() +"] Klientas atsijunge");
            }
        }

        private static void SendCallback(IAsyncResult AR)
        {
            Socket socket = (Socket)AR.AsyncState;
            socket.EndSend(AR);
            socket.BeginReceive(_buffer, 0, _buffer.Length, SocketFlags.None, new AsyncCallback(ReceiveCallback), socket);
        }
    }
}