/**********************************************************************
 * Copyright (c) 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 *
 * Contributors:
 *    IBM - Initial API and implementation
 **********************************************************************/
package net.sourceforge.phpdt.monitor.core.internal;

import java.io.InterruptedIOException;
import java.net.*;

import net.sourceforge.phpdt.monitor.core.IMonitor;
/**
 * The actual TCP/IP monitoring server. This is a thread that
 * listens on a port and relays a call to another server.
 */
public class AcceptThread {
	protected IMonitor monitor;

	protected boolean alive = true;
	protected ServerSocket serverSocket;
	
	protected Thread thread;
	
	class ServerThread extends Thread {
		/**
		 * Actual running of the server proxy.
		 */
	   public void run() {
		   // create a new server socket
		   try {
			   serverSocket = new ServerSocket(monitor.getLocalPort());
			   serverSocket.setSoTimeout(2000);
			   
			   Trace.trace(Trace.FINEST, "Monitoring localhost:" + monitor.getLocalPort() + " -> " + monitor.getRemoteHost() + ":" + monitor.getRemotePort());
		   } catch (Exception e) {
			   Trace.trace(Trace.SEVERE, "Could not start monitoring");
			   return;
		   }
		
		   while (alive) {
			   try {
				   // accept the connection from the client
				   Socket localSocket = serverSocket.accept();
		
				   // connect to the remote server
				   Socket remoteSocket = new Socket(monitor.getRemoteHost(), monitor.getRemotePort());
		
				   // relay the call through
				   ProtocolAdapter adapter = (ProtocolAdapter) monitor.getProtocolAdapter();
				   adapter.parse(monitor, localSocket, remoteSocket);
			   } catch (InterruptedIOException e) {
			   	// do nothing
			   } catch (Exception e) {
				   if (alive)
						Trace.trace(Trace.SEVERE, "Error while monitoring", e);
			   }
		   }
	   }
	}

	/**
	 * ServerMonitorThread constructor comment.
	 */
	public AcceptThread(IMonitor monitor) {
		super();
		this.monitor = monitor;
	}
	
	public void startServer() {
		if (thread != null)
			return;
		thread = new ServerThread();
		thread.setDaemon(true);
		thread.start();
	}

	public boolean isRunning() {
		return (thread != null);
	}

	/**
	 * Correctly close the server socket and shut down the server.
	 */
	public void stopServer() {
		try {
			alive = false;
			thread = null;
			serverSocket.close();
		} catch (Exception e) {
			Trace.trace(Trace.SEVERE, "Error stopping server", e);
		}
	}
	
	/**
	 * Returns true if this port is in use.
	 *
	 * @return boolean
	 * @param port int
	 */
	public static boolean isPortInUse(int port) {
		ServerSocket s = null;
		try {
			s = new ServerSocket(port);
		} catch (SocketException e) {
			return true;
		} catch (Exception e) {
			return true;
		} finally {
			if (s != null) {
				try {
					s.close();
				} catch (Exception e) { }
			}
		}

		return false;
	}
}