//
// System.Runtime.Remoting.Channels.Tcp.TcpClientTransportSink.cs
//
// Author: Dietmar Maurer (dietmar@ximian.com)
//         Lluis Sanchez (lsg@ctv.es)
//
// 2002 (C) Copyright, Ximian, Inc.
//

using System;
using System.Runtime.Remoting.Channels;
using System.Runtime.Remoting.Messaging;
using System.Collections;
using System.IO;
using System.Threading;

namespace System.Runtime.Remoting.Channels.Tcp
{
	public class TcpClientTransportSink : IClientChannelSink
	{
		string _host;
		string _objectUri;
		int _port;
		
		public TcpClientTransportSink (string url)
		{
			_host = TcpChannel.ParseTcpURL (url, out _objectUri, out _port);
		}

		public IDictionary Properties
		{
			get 
			{
				return null;
			}
		}

		public IClientChannelSink NextChannelSink
		{
			get 
			{
				// we are the last one
				return null;
			}
		}

		public void AsyncProcessRequest (IClientChannelSinkStack sinkStack, IMessage msg,
			ITransportHeaders headers, Stream requestStream)
		{
			TcpConnection connection = null;
			try
			{
				// Sends the stream using a connection from the pool
				// and creates a WorkItem that will wait for the
				// response of the server

				connection = TcpConnectionPool.GetConnection (_host, _port);
				TcpMessageIO.SendMessageStream (connection.Stream, requestStream, headers, connection.Buffer);
				sinkStack.Push (this, connection);
				ThreadPool.QueueUserWorkItem (new WaitCallback(ReadAsyncTcpMessage), sinkStack);
			}
			catch
			{
				if (connection != null) connection.Release();
				throw;
			}
		}

		private void ReadAsyncTcpMessage(object data)
		{
			// This method is called by a new thread to asynchronously
			// read the response to a request

			// The stack was provided as state data in QueueUserWorkItem
			IClientChannelSinkStack stack = (IClientChannelSinkStack)data;

			// The first sink in the stack is this sink. Pop it and
			// get the status data, which is the TcpConnection used to send
			// the request
			TcpConnection connection = (TcpConnection)stack.Pop(this);

			try
			{
				ITransportHeaders responseHeaders;

				// Read the response, blocking if necessary
				MessageType type = TcpMessageIO.ReceiveMessageType (connection.Stream);

				if (type != MessageType.MethodMessage)
					throw new RemotingException ("Unknown response message from server");

				Stream responseStream = TcpMessageIO.ReceiveMessageStream (connection.Stream, out responseHeaders, connection.Buffer);

				// Free the connection, so it can be reused
				connection.Release();
				connection = null;

				// Ok, proceed with the other sinks
				stack.AsyncProcessResponse (responseHeaders, responseStream);
			}
			catch
			{
				if (connection != null) connection.Release();
				throw;
			}
		}
	
		public void AsyncProcessResponse (IClientResponseChannelSinkStack sinkStack,
			object state, ITransportHeaders headers,
			Stream stream)
		{
			// Should never be called
			throw new NotSupportedException();
		}

		public Stream GetRequestStream (IMessage msg, ITransportHeaders headers)
		{
			return null;
		}
		
		public void ProcessMessage (IMessage msg,
			ITransportHeaders requestHeaders,
			Stream requestStream,
			out ITransportHeaders responseHeaders,
			out Stream responseStream)
		{
			TcpConnection connection = null;
			try
			{
				// Sends the message
				connection = TcpConnectionPool.GetConnection (_host, _port);
				TcpMessageIO.SendMessageStream (connection.Stream, requestStream, requestHeaders, connection.Buffer);

				// Reads the response
				MessageType type = TcpMessageIO.ReceiveMessageType (connection.Stream);

				if (type != MessageType.MethodMessage)
					throw new RemotingException ("Unknown response message from server");

				responseStream = TcpMessageIO.ReceiveMessageStream (connection.Stream, out responseHeaders, connection.Buffer);
			}
			finally
			{
				if (connection != null) 
					connection.Release();
			}
		}

	}


}