////////////////////////////////////////////////////////////////////////////////
//
//  Microsoft Research Singularity
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//
//  Note:   Simple Singularity telnet daemon
//

// TODO:
// - Graceful server shutdown?
// - non-null syntax
// - catch all appropriate exceptions
// - remove debugging traces
// - limit the number of simultaneous telnet sessions?
// - handle "exit" in shell gracefully
// - handle "client disconnect" gracefully

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using Microsoft.Singularity.Io;
using Microsoft.Singularity.Channels;
using Microsoft.Contracts;
using Microsoft.SingSharp.Reflection;
using Microsoft.Singularity.Applications;
using Microsoft.Singularity.Io;
using Microsoft.Singularity.Configuration;
[assembly: Transform(typeof(ApplicationResourceTransform))]

namespace Microsoft.Singularity.Telnetd
{
    [ConsoleCategory(DefaultAction=true)]
    internal class Parameters {
        [InputEndpoint("data")]
        public readonly TRef<UnicodePipeContract.Exp:READY> Stdin;

        [OutputEndpoint("data")]
        public readonly TRef<UnicodePipeContract.Imp:READY> Stdout;

        reflective internal Parameters();

        internal int AppMain() {
            return Telnetd.AppMain(this);
        }
    }


    public sealed class Telnetd
    {
        internal static int AppMain(Parameters! config)
        {
            Console.WriteLine("Singularity Telnet Daemon - starting.");
            Listener listener = new Listener(23);
            listener.Start();
            while (true) {
                Socket socket = listener.Accept();
                Console.WriteLine("Singularity Telnet Daemon - accepting connection");
                Connection connection = new Connection(socket);
                connection.Start();
            }
            Console.WriteLine("Singularity Telnet Daemon - stopping.");
            return 0;
        }
    }
}