/***************************************************************************
 *   Copyright (C) by Fabrizio Montesi                                     *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU Library General Public License as       *
 *   published by the Free Software Foundation; either version 2 of the    *
 *   License, or (at your option) any later version.                       *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this program; if not, write to the                 *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 *                                                                         *
 *   For details about the authors of this software, see the AUTHORS file. *
 ***************************************************************************/

package jolie.runtime.embedding;

import jolie.runtime.JavaService;
import java.io.IOException;

import java.util.HashMap;
import java.util.Map;
import jolie.Interpreter;
import jolie.net.CommChannel;
import jolie.net.CommMessage;
import jolie.net.PollableCommChannel;
import jolie.runtime.InvalidIdException;


// TODO: this should not be polled

/**
 * @author Fabrizio Montesi
 */
public class JavaCommChannel extends CommChannel implements PollableCommChannel
{
	private final JavaService javaService;
	private final Map< Long, CommMessage > messages = new HashMap< Long, CommMessage >();

	public JavaCommChannel( JavaService javaService )
	{
		this.javaService = javaService;
	}

	public boolean isReady()
	{
		return messages.isEmpty() == false;
	}

	@Override
	protected void disposeForInputImpl()
		throws IOException
	{
		Interpreter.getInstance().commCore().registerForPolling( this );
	}

	@Override
	public CommChannel createDuplicate()
	{
		return new JavaCommChannel( javaService );
	}

	@Override
	public void send( CommMessage message )
		throws IOException
	{
		sendImpl( message );
	}

	protected void sendImpl( CommMessage message )
		throws IOException
	{
		try {
			CommMessage response = javaService.callOperation( message );
			synchronized( messages ) {
				messages.put( message.id(), response );
				messages.notifyAll();
			}
		} catch( IllegalAccessException e ) {
			throw new IOException( e );
		} catch( InvalidIdException e ) {
			throw new IOException( e );
		}
	}

	protected CommMessage recvImpl()
		throws IOException
	{
		throw new IOException( "Unsupported operation" );
	}

	@Override
	public CommMessage recvResponseFor( CommMessage request )
		throws IOException
	{
		boolean keepRun = true;
		CommMessage ret = null;
		synchronized( messages ) {
			while( keepRun ) {
				if ( (ret=messages.remove( request.id() )) == null ) {
					try {
						messages.wait();
					} catch( InterruptedException e ) {}
				} else {
					keepRun = false;
				}
			}
		}
		return ret;
	}

	/*protected CommMessage recvImpl()
		throws IOException
	{
		CommMessage ret = null;
		synchronized( messages ) {
			while( messages.isEmpty() ) {
				try {
					messages.wait();
				} catch( InterruptedException e ) {}
			}
			ret = messages.remove( 0 );
		}
		if ( ret == null ) {
			throw new IOException( "Unknown exception occurred during communications with a Java Service" );
		}
		return ret;
	}*/

	protected void closeImpl()
	{}
}