/*
  Copyright 2006 by Sean Luke
  Licensed under the Academic Free License version 3.0
  See the file "LICENSE" for more information
*/


package ec.app.lawnmower.func;
import ec.*;
import ec.app.lawnmower.*;
import ec.gp.*;
import ec.util.*;

/* 
 * Left.java
 * 
 * Created: Wed Nov  3 18:26:37 1999
 * By: Sean Luke
 */

/**
 * @author Sean Luke
 * @version 1.0 
 */

public class Left extends GPNode
    {
    public String toString() { return "left"; }

/*
  public void checkConstraints(final EvolutionState state,
  final int tree,
  final GPIndividual typicalIndividual,
  final Parameter individualBase)
  {
  super.checkConstraints(state,tree,typicalIndividual,individualBase);
  if (children.length!=0)
  state.output.error("Incorrect number of children for node " + 
  toStringForError() + " at " +
  individualBase);
  }
*/
    public int expectedChildren() { return 0; }

    public void eval(final EvolutionState state,
        final int thread,
        final GPData input,
        final ADFStack stack,
        final GPIndividual individual,
        final Problem problem)
        {
        Lawnmower p = (Lawnmower)problem;
        LawnmowerData d = (LawnmowerData)input;

        switch (p.orientation)
            {
            case Lawnmower.O_UP:
                p.orientation = Lawnmower.O_LEFT; 
                break;
            case Lawnmower.O_LEFT:
                p.orientation = Lawnmower.O_DOWN;
                break;
            case Lawnmower.O_DOWN:
                p.orientation = Lawnmower.O_RIGHT;
                break;
            case Lawnmower.O_RIGHT:
                p.orientation = Lawnmower.O_UP;
                break;
            default:  // whoa!
                state.output.fatal("Whoa, somehow I got a bad orientation! (" + p.orientation + ")");
                break;
            }
        //p.moves++;

        // return [0,0]
        d.x = 0;
        d.y = 0;
        }
    }