/*
 * FSMNode.java
 *
 * Created on February 4, 2003, 6:43 PM
 */

package jaga.pj.circuits.experiment;

import java.util.Vector;
import java.util.Random;

/** Intended to represent a Node in the transition graph of a Finite State Machine.
 * Optimized for machine with four fully connected nodes where one connection should
 * never be removed.
 * @author  Michael Garvie
 * @version 
 */
public class FSMNode implements java.io.Serializable  {

    FSMEdge fixed;
    Vector edges;
    Random rnd;
    boolean fixedTouched = false;
    
    
    /** Creates new FSMNode */
    public FSMNode() {
        edges = new Vector();
        rnd = new Random();
    }
    
    public FSMNode( Random prnd )
    {
        this();
        rnd = prnd;
    }
    
    public void connectTo( FSMEdge e1, FSMEdge e2, FSMEdge e3, FSMEdge e4 )
    {
        fixed = e1;
        edges.add( e1 );
        edges.add( e2 );
        edges.add( e3 );
        edges.add( e4 );
    }
    
    public void connectTo( FSMEdge e1, FSMEdge e2, FSMEdge e3 )
    {
        fixed = e1;
        edges.add( e1 );
        edges.add( e2 );
        edges.add( e3 );
    }

    public void connectTo( FSMEdge e1, FSMEdge e2 )
    {
        fixed = e1;
        edges.add( e1 );
        edges.add( e2 );
    }

    public boolean remove( FSMEdge e )
    {
        if( e == fixed )
        {
            if( fixedTouched )
            {
                return false;
            }else
            {
                fixedTouched = true;
                return true;
            }
        }
        edges.remove( e );
        return true;
    }
    
    public FSMEdge pick()
    {
        return ( FSMEdge ) edges.get( rnd.nextInt( edges.size() ) );
    }
}