/*
 * @(#)Puzzle.java	
 *
 * Copyright (c) 1996 Aaron Fuegi All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL or COMMERCIAL purposes and
 * without fee is hereby granted. 

 * Acknowledgments:
 *    Thanks to Jason Heirtzler, previously of Boston University who wrote 
 *      this game as a script long ago.
 *    Thanks to Arthur van Hoff whose TicTacToe code formed a rough basis for
 *      this code.
 */

import java.awt.*;
import java.awt.image.*;
import java.net.*;
import java.applet.*;

/**
 * A 9-piece Puzzle applet. A very simple, and mostly brain-dead
 * implementation of this dumb game! <p>

 * @author Aaron Fuegi
 */
public
class Puzzle extends Applet {
    Image offscreenImg;
    Graphics offscreenG;
    int curlocs[] = {-1,-1,-1,-1,-1,-1,-1,-1,-1};
    static final int WIN = 1;
    static final int DEBUG = 0;
    static final int height=180;
    static final int width=177;
    int xoff = width / 3;
    int yoff = height / 3;
    int numPieces=9;
    int piecesHigh=3;
    int piecesAcross=3;
    int openloc;
    int ininit=1;
    int firstMove=0;
    int done[];
    int alldone=0;

    /**
     * Figure what the status of the game is.
     */
    int status() {	
	for (int i=0;i<9;i++)
		if (curlocs[i]!=i) { return -1; }
	return WIN;
    }

    /**
     * The image for white.
     */
    Image squares[];
    Image victory;
    Image again;
    Image win;

    /**
     * Initialize the applet. Resize and load images.
     */
    public void init() {
	int i,j;
	int temp = -1;

	offscreenImg = createImage(this.size().width,this.size().height);
        offscreenG=offscreenImg.getGraphics();

	offscreenG.setColor(getBackground());
	offscreenG.fillRect(0,0,this.size().width,this.size().height);

	showStatus("Beginning Loading Pieces...");

	done=new int[numPieces];
	for(i=0;i<9;i++) done[i]=0;

	squares = new Image[numPieces];
	for (i=0;i<9;i++) { 
	  squares[i] = getImage(getCodeBase(), "images/puzzle/p"+i+".gif");
   	  showStatus("Loaded piece "+i+"/"+numPieces);
	}

	showStatus("Loading other images for end game");
	victory = getImage(getCodeBase(), "images/puzzle/victory.gif");
	again = getImage(getCodeBase(), "images/puzzle/again.gif");
	if (DEBUG==1) win = getImage(getCodeBase(), "images/puzzle/win.gif");

	setBoard();
}

public void setBoard() {
	int i,j;
	int movedir;
	int deformValue;

	/* Set board to winning position */
	for (i=0;i<9;i++) {
		curlocs[i]= i;
	}
	openloc=4;
	
	showStatus("Setting up Board");

	/* Make random number of moves to deform board position */
	deformValue = 150 + (int)Math.floor(Math.random()*100.00);

	for (i=0;i<deformValue;i++) {
		movedir = (int)Math.floor(Math.random()*4);
		while (((openloc<3)&&(movedir==0))||
	 	       (((openloc%3)==0)&&(movedir==1))||
		       ((openloc>5)&&(movedir==2))||
		       ((((openloc+1)%3)==0)&&(movedir==3)))
			movedir = (int)Math.floor(Math.random()*4);
		deformmove(movedir);
	}

	showStatus("Begin play");	

	firstMove=1;
    }


    public void deformmove(int dir) {
	int swapval = -1;
	int r,c;

	/* Check up,down,left,right */
	if (dir==0) { swapval=openloc-3; }
	if (dir==2) { swapval=openloc+3; }
	if (dir==1) { swapval=openloc-1; }
	if (dir==3) { swapval=openloc+1; }
	
	/* No need for dummy variable since black is always 4 */
	curlocs[openloc]=curlocs[swapval];
	curlocs[swapval]=4;
	openloc=swapval;
    }

    public void update(Graphics g) {
	paint(g);
    }

    /**
     * Paint it.
     */
    public void paint(Graphics g) {
	int i = 0;

	if (firstMove==1) {
	    if (alldone==1) firstMove=0;
	    for (int r = 0 ; r < 3 ; r++) {
		for (int c = 0 ; c < 3 ; c++) {
		    int loc=r*3+c;
		    int whichPiece=curlocs[loc];
		    offscreenG.drawImage(squares[whichPiece], c*xoff + 1, r*yoff + 1, this);
		}
	    }
	}

	if (status()==WIN) {
	    showStatus("Game Over: Victory");	
	    offscreenG.drawImage(victory, 200, 1, this);
	    offscreenG.drawImage(again, 300, 119, this);
	}
	else if (DEBUG==1)
	    offscreenG.drawImage(win, 300, 119, this);
	else {
	    offscreenG.fillRect(200,1,300,160);
	}
	g.drawImage(offscreenImg,0,0,this);
    }

    public boolean imageUpdate(Image img, int flags, int x, int y, int wid, int ht) {
        int i;
	int alldonehere=1;

	if (flags == ALLBITS) {
	    for(i=0;i<9;i++) {
		if (img.equals(squares[i])) { 
		    done[i]=1; 
		}
	    }

	    for(i=0;i<9;i++) {
		if (done[i]!=1) alldonehere=0;
	    }
	    if (alldonehere==1) {
		alldone=1;
		repaint();
	    }
        } 
	return true;
    }

    public int makemove(int row, int col) {
	int loc=row*3+col;
	int r,c,whichPiece;
	
	int swapval = -1;

	/* Check up,down,left,right */
	if ((row!=0)&&(curlocs[(loc-3)]==4)) { swapval=loc-3; }
	if ((row!=2)&&(curlocs[(loc+3)]==4)) { swapval=loc+3; }
	if ((col!=0)&&(curlocs[(loc-1)]==4)) { swapval=loc-1; }
	if ((col!=2)&&(curlocs[(loc+1)]==4)) { swapval=loc+1; }
	
	if (swapval != -1) {
		/* No need for dummy variable since black is always 4 */
		curlocs[swapval]=curlocs[loc];
		curlocs[loc]=4;
		r=swapval/3;
		c=swapval % 3;
		whichPiece=curlocs[swapval];
		offscreenG.drawImage(squares[whichPiece], c*xoff + 1, r*yoff + 1, this);
		r=loc/3;
		c=loc % 3;
		whichPiece=4;
		offscreenG.drawImage(squares[whichPiece], c*xoff + 1, r*yoff + 1, this);
		return 1;
	}
	else {
		return swapval;
	}
    }


    /**
     * The user has clicked in the applet. Figure out where
     * and see if a legal move is possible. If it is a legal
     * move, respond with a legal move (if possible).
     */
    public boolean mouseUp(Event evt, int x, int y) {
	if ((status()==WIN)&&(x>300)&&(x<400)&&(y>119)&&(y<159)) {
	    setBoard(); 
	    repaint(); 
	    return true; 
	}

	// Figure out the row/colum
	int c = (x * 3) / width;
	int r = (y * 3) / height;
	if ((x>300)&&(x<400)&&(y>119)&&(y<159)&&(DEBUG==1)) {
	    for(int i=0;i<9;i++)
		curlocs[i]=i;
	    firstMove=1;
	}
	else if ((c>=0)&&(c<3)&&(r>=0)&&(r<3)) {
	    if (DEBUG==1) System.out.println("Made move");
	    makemove(r,c);
	}
	repaint();
	    
	showStatus("Play in progress");	

	return true;
    }


    public String getAppletInfo() {
	return "9-Puzzle by Aaron Fuegi";
    }
}