using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.Threading;
using System.Text.RegularExpressions;

namespace WebServer
{
    class HttpProcess
    {
        Socket s;

        public HttpProcess(Socket s)
        {
            this.s = s;
        }

        public void process()
        {
            string head = "";
            int len = 0;
            byte[] buf = new byte[1];
            do
            {
                len = s.Receive(buf);
                head += Encoding.ASCII.GetString(buf);
            } while (len > 0 && !head.EndsWith("\r\n\r\n"));

            Console.WriteLine(head);

            string content = "ok";

            string raw = string.Format(@"HTTP/1.1 200 OK
Content-Length: {0}
Content-Type: text/html

{1}", Encoding.Default.GetByteCount(content), content);

            Console.WriteLine(raw);

            s.Send(Encoding.Default.GetBytes(raw));
            s.Shutdown(SocketShutdown.Both);
            s.Close();
        }
    }
    public class HttpServer
    {
        static void listen()
        {
            Socket listener = new Socket(0, SocketType.Stream, ProtocolType.Tcp);
            IPEndPoint endpoint = new IPEndPoint(IPAddress.Any, 81);
            listener.Bind(endpoint);
            listener.Blocking = true;
            listener.Listen(-1);
            while (true)
            {
                Socket s = listener.Accept();
                HttpProcess p = new HttpProcess(s);
                Thread thread = new Thread(new ThreadStart(p.process));
                thread.Start();
            }
        }



        public static int Main(String[] args)
        {
            Thread thread = new Thread(new ThreadStart(listen));
            thread.Start();
            return 0;
        }
    }

}