/*
    Copyright (C) 2004  [Jörg Rüdenauer]
    
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU 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 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.
    
*/

import java.awt.Color;
import java.util.Iterator;
import java.util.List;

import fdda.algorithm.Message;
import fdda.algorithm.Node;
import fdda.algorithm.NodeAdapter;
import fdda.algorithm.WrongStateException;

/**
 * Node for the demonstration of the 'echo' algorithm to flood a network.
 */
public class EchoFlooding extends NodeAdapter {
  
  /** how many messages have I received yet? */
  private int messageCount;
  
  /** who sent the explorer message? */
  private Node explorerSender;
  
  /** did this node start the algorithm? */
  private boolean starter;

  /* (non-Javadoc)
   * @see fdda.algorithm.Node#prepareForStart()
   */
  protected void prepareForStart() {
    setPrimaryColor(Color.WHITE);
    messageCount = 0;
    explorerSender = null;
    starter = false;
  }

  /* (non-Javadoc)
   * @see fdda.algorithm.Node#start()
   */
  protected void start() throws WrongStateException {
    setPrimaryColor(Color.RED);
    List neighbours = this.getNeighbours();
    for (Iterator it = neighbours.iterator(); it.hasNext(); ) {
      Node neighbour = (Node) it.next();
      Message explorer = this.createMessage(neighbour);
      explorer.setColor(Color.RED);
      explorer.setLabel("Info");
      explorer.send();
    }
    starter = true;
  }

  /* (non-Javadoc)
   * @see fdda.algorithm.Node#messageReceived(fdda.algorithm.Node, fdda.algorithm.Message)
   */
  protected void messageReceived(Node sender, Message message)
  throws WrongStateException {
    if (!starter && (messageCount == 0)) {
      setPrimaryColor(Color.RED);
      explorerSender = sender;
      List neighbours = this.getNeighbours();
      for (Iterator it = neighbours.iterator(); it.hasNext(); ) {
        Node neighbour = (Node) it.next();
        if (neighbour == sender) continue;
        Message explorer = this.createMessage(neighbour);
        explorer.setColor(Color.RED);
        explorer.setLabel("Info");
        explorer.send();
      }
    }
    messageCount++;
    if (messageCount == this.getNeighbours().size()) {
      setPrimaryColor(Color.GREEN);
      if (explorerSender != null) {
        Message echo = this.createMessage(explorerSender);
        echo.setColor(Color.GREEN);
        echo.setLabel("Echo");
        echo.send(); 
      }
      // else algorithm is terminated
      else {
        assert starter;
      }
    }
  }

}