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

namespace KnockKnock.Lib
{
	internal class Listener
	{
		public delegate void ConnectedEvent(Listener sender, Socket socket);
		public event ConnectedEvent Connected;

		int port;
		Socket listener;
		

		public Listener(int port)
		{
			this.port = port;
		}

		public void Start()
		{
			listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
			listener.Bind(new IPEndPoint(IPAddress.Loopback, this.port));
			listener.Listen();
			listener.BeginAccept(this.ListenerAcceptCallback, null);
		}

		public void Stop()
		{
			listener.Close();
			listener = null;
		}

		protected void ListenerAcceptCallback(IAsyncResult result)
		{
			if (listener == null) return;
			Socket client = listener.EndAccept(result);
			listener.BeginAccept(this.ListenerAcceptCallback, null);
			this.Connected(this, client);
		}
	}
}