/*
 * $Id: IpWatch.java 3905 2008-07-28 13:55:03Z uckelman $
 *
 * Copyright (c) 2007-2008 by Rodney Kinney
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License (LGPL) as published by the Free Software Foundation.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, copies are available
 * at http://www.opensource.org.
 */
package VASSAL.chat.peer2peer;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class IpWatch implements Runnable {
  private PropertyChangeSupport propSupport = new PropertyChangeSupport(this);
  private String currentIp;
  private long wait = 1000;

  public IpWatch(long waitInterval) {
    wait = waitInterval;
    currentIp = findIp();
  }

  public IpWatch() {
    this(1000);
  }

  public void addPropertyChangeListener(PropertyChangeListener l) {
    propSupport.addPropertyChangeListener(l);
  }

  public void run() {
    while (true) {
      String newIp = findIp();
      propSupport.firePropertyChange("address", currentIp, newIp); //$NON-NLS-1$
      currentIp = newIp;

      try {
        Thread.sleep(wait);
      }
      catch (InterruptedException ex) {
      }
    }
  }

  public String getCurrentIp() {
    return currentIp;
  }

  private String findIp() {
    try {
      InetAddress a[] = InetAddress.getAllByName(InetAddress.getLocalHost().getHostName());
      final StringBuilder buff = new StringBuilder();
      for (int i = 0; i < a.length; ++i) {
        buff.append(a[i].getHostAddress());
        if (i < a.length - 1) {
          buff.append(","); //$NON-NLS-1$
        }
      }
      return buff.toString();
    }
    // FIXME: review error message
    catch (UnknownHostException e) {
      return null;
    }
  }

  public static void main(String[] args) {
    IpWatch w = new IpWatch();
    w.addPropertyChangeListener(new PropertyChangeListener() {
      public void propertyChange(PropertyChangeEvent evt) {
        System.out.println("Address = " + evt.getNewValue()); //$NON-NLS-1$
      }
    });
    System.out.println("Address = " + w.getCurrentIp()); //$NON-NLS-1$
    new Thread(w).start();
  }
}
