using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

namespace NakedNetwork
{
  using POP3Client;

  public class NakedNetwork
  {
    protected mutable socket : Socket;


    public this ()
    {
      socket = null;
    }


    public Connect () : void
    {
      if (socket != null) Close ()
      else
      {
        socket = Socket (AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

        socket.SetSocketOption (SocketOptionLevel.Socket, SocketOptionName.ReceiveTimeout, 120000);
        socket.SetSocketOption (SocketOptionLevel.Socket, SocketOptionName.SendTimeout, 120000);
      }
    }

    
    protected Send (toSend : string) : void
    {
//      System.Console.WriteLine ("Debug: Send: {0}", toSend);

      try
      {
        ignore (socket.Send (Encoding.ASCII.GetBytes (toSend + "\r\n")));
      }
      catch
      {
        | e => throw POP3Client.CommandException (Error.FATALERROR, e.Message);
      };
    }

    protected Receive (expected : int, ended : string) : string
    {
      mutable result    = String.Empty;
      mutable buffer    = array (1024);
      mutable received  = 0;
      mutable retries   = 0;
      mutable expected_ = expected;

      do
      {
        try
        {
          received = socket.Receive (buffer, 1024, SocketFlags.None);
        }
        catch
        {
          | e => throw POP3Client.CommandException (Error.FATALERROR, e.Message);
        };

        if (received == 0)
        {
          retries = retries + 1;
          if (retries >= 100) throw POP3Client.CommandException (Error.FATALERROR, "Socket closed") else {};
        }
        else
        {
          result    = result + Encoding.ASCII.GetString (buffer, 0, received);
          expected_ = expected_ - received;
        };
      }
      while (expected_ < 0 && (received > 0 && !result.EndsWith (ended)) || expected_ > 0 || received == 0);

      result;
    }

    protected Receive (expected : int) : string
    {
      Receive (expected, String.Empty);
    }
  
    protected Receive (ended : string) : string
    {
      Receive (-1, ended);
    }
  
    protected Receive () : string
    {
      Receive (-1);
    }

    public Close () : void
    {
      if (socket != null && socket.Connected)
      {
        socket.Shutdown (SocketShutdown.Send);
        socket.Close ();
      }
      else {};
      
      socket = null;
    }
  }
}