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

namespace UDPoverTCP_TunelClient
{
    class UDPoverTCP_TunelClient
    {
        static void Greetings(){
            Console.WriteLine("Brought to you by The Computer Engineering Group,");
            Console.WriteLine("Department of Electronics, UTFSM");
            Console.WriteLine("It was just born on October 4th 2010.");
            Console.WriteLine("Please treat it with care and be patience.");
            Console.WriteLine("We appreciate your comments to improve it.");
        }
        static void Main(string[] args)
        {
            Int32 remoteTCPport, localUDPport;
            string remoteHost = "localhost";
            try{
                switch (args.Length) {
                case 2:
                    localUDPport = Convert.ToInt32(args[0]);
                    remoteTCPport = Convert.ToInt32(args[1]);
                    break;
                case 3:
                    localUDPport = Convert.ToInt32(args[0]);
                    remoteHost = args[1];
                    remoteTCPport = Convert.ToInt32(args[2]);
                    break;
                default:
                    Console.WriteLine("Usage: Executable Local_UDP_Port [Remote_Server_Host] Remote_Server_Port");
                    Console.WriteLine("\"localhost\" is used when Remote_Server_Host is missing.");
                    return;
                }
                Greetings();
                UdpClient udpServer_sock = new UdpClient(localUDPport);
                TcpClient tcpClient_sock = new TcpClient(remoteHost, remoteTCPport);
                GatewayUDP_TCP gateway = new GatewayUDP_TCP(tcpClient_sock, udpServer_sock);
                Thread fromUDP2TCP_thread = new Thread(gateway.relayDatagramFromUDPtoTCP);
                fromUDP2TCP_thread.Start();
                Thread fromTCP2UDP_thread = new Thread(gateway.relayDatagramFromTCPtoUDP);
                fromTCP2UDP_thread.Start();
                fromUDP2TCP_thread.Join();
                fromTCP2UDP_thread.Join();
                udpServer_sock.Close();
                tcpClient_sock.Close();
            } catch (Exception e ) {
               Console.WriteLine(e.ToString());
            }
        }
    }
}