/*
 * Copyright (C) 2005-2008 Alfresco, Inc.
 *
 * Licensed under the Mozilla Public License version 1.1 
 * with a permitted attribution clause. You may obtain a
 * copy of the License at
 *
 *   http://www.alfresco.org/legal/license.txt
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the
 * License.
 */
package org.alfresco.jlan.server;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.SocketException;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;

import org.alfresco.jlan.debug.Debug;
import org.alfresco.jlan.smb.server.PacketHandler;

/**
 * Channel Session Handler Class
 * 
 * <p>Base class for channel based session handler implementations.
 * 
 * @author gkspencer
 */
public abstract class ChannelSessionHandler extends SessionHandlerBase {

	// Server socket channel for receiving incoming connections

	private ServerSocketChannel m_srvSockChannel;

	/**
	 * Class constructor
	 * 
	 * @param name String
	 * @param protocol String
	 * @param server NetworkServer
	 * @param addr InetAddress
	 * @param port int
	 */
	public ChannelSessionHandler(String name, String protocol, NetworkServer server, InetAddress addr, int port) {
		super(name, protocol, server, addr, port);
	}

	/**
	 * Return the server socket channel
	 * 
	 * @return ServerSocketChannel
	 */
	public final ServerSocketChannel getSocketChannel() {
		return m_srvSockChannel;
	}
	
	/**
	 * Initialize the session handler
	 * 
	 * @param server NetworkServer
	 */
	public void initializeSessionHandler(NetworkServer server)
		throws IOException {

		// Create the server socket channel
		
		m_srvSockChannel = ServerSocketChannel.open();
		
		// Open the server socket

		InetSocketAddress sockAddr = null;
		
		if ( hasBindAddress())
			sockAddr = new InetSocketAddress( getBindAddress(), getPort());
		else
			sockAddr = new InetSocketAddress( getPort());

		// Bind the socket
		
		m_srvSockChannel.socket().bind( sockAddr, getListenBacklog());
		
		// Set the allocated port

		if ( getPort() == 0)
			setPort(m_srvSockChannel.socket().getLocalPort());

		// DEBUG

		if ( Debug.EnableInfo && hasDebug()) {
			Debug.print("[" + getProtocolName() + "] Binding " + getHandlerName() + " session handler to address : ");
			if ( hasBindAddress())
				Debug.println(getBindAddress().getHostAddress());
			else
				Debug.println("ALL");
		}
	}

	/**
	 * Close the session handler
	 * 
	 * @param server NetworkServer
	 */
	public void closeSessionHandler(NetworkServer server) {

		// Request the main listener thread shutdown

		setShutdown( true);

		try {

			// Close the server socket to release any pending listen

			if ( m_srvSockChannel != null)
				m_srvSockChannel.close();
		}
		catch (SocketException ex) {
		}
		catch (Exception ex) {
		}
	}

	/**
	 * Create a packet handler for the new client socket connection
	 * 
	 * @param sockChannel SocketChannel
	 * @return PacketHandler
	 * @exception IOException
	 */
	public abstract PacketHandler createPacketHandler( SocketChannel sockChannel)
		throws IOException;
}