/* FILE NAME: HungryWorld.java
 * AUTHOR: Stella
 * DATE: Oct 18 2007
 * COMMENTS: Creates a buggle World populated with bagels, in a random fashion, so
 * that no bagel is placed in the middle column.
 * Places a buggle in the middle of row one.
 * Sends the buggle out to eat the bagels, according to this rule:
 * In each row, the buggle will eat the bagels to its left or the right, only.
 * Specifically, it will eat the bagels to the right, if there are more bagels
 * to its left than its right. And it will eat the bagels to its left, 
 * if there are more bagels to its left than its right.
 * Each cell that used to contain an eaten bagel, is colored red.
 * MODIFICATION HISTORY:
*/

import java.awt.*;

public class HungryWorld extends RandomBagelWorld {

 public void run () {
  int side = params.getIntParam("side");
  
  //get a HungryBuggle and initialize it
  HungryBuggle harry  = new HungryBuggle();
  harry.setPosition(new  Location(side/2 + 1,1));
  harry.setHeading(Direction.NORTH);
  harry.brushUp();
  
  //send it off to eat the bagels
  harry.eatAllRows();
 }  
 
  //------------------------------------------------------------------------------
  // The following main method is needed to run the applet as an application

  public static void main (String[] args) {
    runAsApplication(new HungryWorld(), "HungryWorld"); 
  }

}
/*****************************************************************************/

class HungryBuggle extends Buggle {
  
  public void eatAllRows() {
    // For each row in the grid, eats the bagels on the side of the buggle 
    // that has more bagels.
    // Does nothing if the number of bagels is the same on both sides. 
    // Starting state: In the middle of the first row, facing NORTH, brush up.
    // Final state: In the middle of the top row, facing NORTH, brush up.
    if (isFacingWall()) {
      eatOneRow();
      return;
    } 
    //if it is not facing wall
    eatOneRow();
    forward(); // move on to continue eating more rows
    eatAllRows();
  }
 
 
 public void eatOneRow() {
   // Eats the bagels on the side of the buggle that has more bagels.
   // Does nothing if the number of bagels is the same on both sides. 
   // Starting state of the buggle:
   // middle of the row, brush up, facing NORTH
   // Does not change the state of the buggle. 
   left();  //face to the WEST
   int numBagelsToLeft = countBagelsAhead();
   right();  right(); //face to the EAST
   int numBagelsToRight = countBagelsAhead();
   left(); //come back to the initial facing
  
  // Compare the numbers, and behave appropriately
  if (numBagelsToLeft == numBagelsToRight) 
    return;
  if (numBagelsToRight > numBagelsToLeft) {
    right();
    eatBagelsAhead();
    left(); //back to initial heading
  }
  if (numBagelsToLeft > numBagelsToRight) {
    left();
    eatBagelsAhead();
    right(); //back to initial heading
  }
 }
 
 public int countBagelsAhead() {
   // Returns the number of bagels ahead of the buggle.
   // Starting state: position in the middle of the row, brush up, 
   // facing the direction it will count the bagels (WEST or EAST).
   // Does not change the state of the buggle.  
   
   int numBagels = 0;
   if (isFacingWall()) return 0;
   //otherwise
   forward();
   if (isOverBagel()) 
     numBagels = 1 + countBagelsAhead();
   else // not over bagel
     numBagels = countBagelsAhead();
   
   backward();
   return numBagels;
 }
 
 public void eatBagelsAhead() {
   // Eats the bagels ahead of the buggle. 
   //Leaves a red square where a bagel was found.
   // Starting state: position in the middle of the row, brush up, 
   // facing the direction it will eat the bagels (WEST or EAST).
   // Does not change the state of the buggle.  
   if (isFacingWall()) return; // do nothing
    //if it is not facing wall
   forward();
   if (isOverBagel() ) {
     pickUpBagel();
     paintCell(Color.red);
     eatBagelsAhead();
     backward();
   }
   else { //not over bagel
     eatBagelsAhead();
     backward();
   }
 }
 
 //This method is *not* used in this solution.
 //However, it might be useful to have handy for your ps6!
 public int numBagelsUnder() {
   if (isOverBagel()) 
     return 1; 
   else return 0;
 }
}