import java.awt.*;
import java.util.*;
import java.net.*;

public class Flip extends java.applet.Applet implements Runnable{
	
	Image offscreen;	// drawing occurs here before copying to screen
	Graphics offG;		// graphics object of offscreen image

	Image show,hide,draw;
	Graphics dg;

	int width=256,height=256,size,drawLevel=3;
	Random rnd = new Random(System.currentTimeMillis());

	Thread runner;
	URL picURL;

	boolean goFlip=false,solved=false,paintAll=true;
	int fi,fj;

	tile[][] map;

//========================================================
//--- primary functions ---
	public Flip(){}
	

	public void init(){
		String val = getParameter("size");
		if (val==null)	size = 4;
		else			size = Integer.parseInt(val);

		picURL = selectPicture();
		show = getImage(picURL);

		draw = createImage(width,height);
		hide = createHide();
		dg = draw.getGraphics();

		offscreen = createImage(width,height);
		offG = offscreen.getGraphics();
		//showToDraw();

		map = new tile[size][size];
		for (int i=0;i<size;i++) 
			for (int j=0;j<size;j++) 
				map[i][j] = new tile();

		for (int count=size*size/2;count>0;count--) {
			int i = (rnd.nextInt()&0x7fffffff)%size;
			int j = (rnd.nextInt()&0x7fffffff)%size;
			flip(i,j);
		}
	}
	

	public void update(Graphics g){
		if (show!=null) {
			showToDraw();
			paintAll = true;
		}
		paint(g);
	}

		
	public void paint(Graphics g){

		if (show==null) show = getImage(picURL);

		if (solved) {
			offG.drawImage(show,0,0,width,height,this);
		}
		else for (int i=0;i<size;i++) for (int j=0;j<size;j++) {

			if (!paintAll && !map[i][j].redraw()) continue;

			drawTile(i,j);
		}

		paintAll = false;
		
		g.drawImage(offscreen,0,0,this);
	}

//--- running functions ---
	public void start(){
		if (runner==null) {
			runner = new Thread(this);
			runner.start();
		}
	}


	public void stop(){
		if (runner!=null) {
			runner.stop();
			runner = null;
		}
	}


	public void run(){
System.out.println("RUN");
		while (!solved){
			if (!goFlip) solved = testForSolved();
			if (goFlip) animateFlip();
			try {runner.sleep(1);}
			catch (InterruptedException e){}
		}
		
		for (;drawLevel>=0;drawLevel--) {
			paintAll = true;
			showToDraw();
			repaint();
			try {runner.sleep(500,0);}
			catch (InterruptedException e){}
		}
	}


	public boolean mouseDown(Event evt,int x,int y){
		if (goFlip || solved) return true;

		flip(x*size/width,y*size/height);
		return true;
	}


//========================================================
//--- private functions ---
	tilt[][] alter = {
		{},
		{},
		{new tilt(0,0,0)},
		{new tilt(0,-1,0),new tilt(1,0,1),
			new tilt(0,1,2),new tilt(-1,0,3),},
		{new tilt(0,-1,0),new tilt(1,0,1),
			new tilt(0,1,2),new tilt(-1,0,3),new tilt(0,0,0),},
		{new tilt(0,-1,0),new tilt(0,-2,0),
			new tilt(1,0,1),new tilt(2,0,1),
			new tilt(0,1,2),new tilt(0,2,2),
			new tilt(-1,0,3),new tilt(-2,0,3),},
		{new tilt(1,-1,0),new tilt(0,-2,0),
			new tilt(1,1,1),new tilt(2,0,1),
			new tilt(-1,1,2),new tilt(0,2,2),
			new tilt(-1,-1,3),new tilt(-2,0,3),new tilt(0,0,0),},
		{new tilt(1,-1,0),new tilt(0,-2,0),new tilt(0,-1,0),
			new tilt(1,1,1),new tilt(2,0,1),new tilt(1,0,1),
			new tilt(-1,1,2),new tilt(0,2,2),new tilt(0,1,2),
			new tilt(-1,-1,3),new tilt(-2,0,3),new tilt(-1,0,3),},
		{new tilt(1,-1,0),new tilt(1,-2,0),new tilt(2,-1,0),
			new tilt(1,1,1),new tilt(1,2,1),new tilt(2,1,1),
			new tilt(-1,1,2),new tilt(-1,2,2),new tilt(-2,1,2),
			new tilt(-1,-1,3),new tilt(-2,-1,3),new tilt(-1,-2,3),},
	};

	void flip(int x,int y){
	boolean more = true;
	tile temp = new tile();
	tilt[] tp;

		goFlip = true;

		tp = alter[size];

		for (int i=0;i<tp.length;i++) {
			int dx = x + tp[i].x;
			if (dx<0 || dx>=size) continue;
			int dy = y + tp[i].y;
			if (dy<0 || dy>=size) continue;

			map[dx][dy].flip(tp[i].dir);
		}
	}


	void animateFlip(){
		goFlip = false;

		for (int i=0;i<size;i++) for (int j=0;j<size;j++) {
			if (map[i][j].redraw()) goFlip = true;
		}

		repaint();
	}


//--- Load & Create Functions ---
	Image createHide(){
	Image temp;
	Graphics ig;
	int value = width/size, num;

		temp = createImage(value,value);
		ig = temp.getGraphics();

		for (int i=0;i<value/2;i++) {

			if (i<value/4)	{
				ig.setColor(new Color(1024*i/value,0,0));
			}
			else {
				num = 256 * i / value;
				ig.setColor(new Color(255,num,num));
			}

			ig.drawRect(i,i,value-i*2,value-i*2);
		}

		ig.dispose();
		return temp;
	}


	void showToDraw(){
		if (show==null) return;

		dg.drawImage(show,0,0,width,height,this);
		if (drawLevel==0) return;

		for (int i=0;i<size;i++) for (int j=0;j<size;j++) {
		int x = width * i / size;	int dx = width * (i+1) / size - x;
		int y = height * j / size;	int dy = height * (j+1) / size - y;

			dg.setColor(new Color(0,0,0));
			dg.drawRect(x,y,dx,dy);
			if (drawLevel==1) continue;

			dg.setColor(new Color(64,64,64));
			dg.drawRect(++x,++y,dx-=2,dy-=2);
			if (drawLevel==2) continue;

			dg.setColor(new Color(128,128,128));
			dg.drawRect(++x,++y,dx-=2,dy-=2);
			if (drawLevel==3) continue;
		}
	}

	boolean testForSolved(){
		for (int i=0;i<size;i++) for (int j=0;j<size;j++) 
			if (map[i][j].showHide==false) return false;
		return true;
	}


//--- select picture() ---
	String[] names = {
		"bagt2","batk1","bcontrol","bmres","bres1","bres2","bres3",
		"cagt1","cres2","eagt2",
		"ebagt","eepagt","eres4","eres5","eres6",
		"magt2",
		"pagt1","patk1","pconceal","pres1","pres3","pres4","pscout",
		"pwarlord",
	};

	//int select = 0;		// for testing

	URL selectPicture(){
	URL tmp;
	Random rnd = new Random(System.currentTimeMillis());
	int ix = rnd.nextInt();

		ix = (ix<0?-ix:ix) % names.length;
		//ix = select % names.length;		// for testing
		//select++;

		try { tmp = new URL(getCodeBase(),"art/"+names[ix]+".jpg");}
		catch (MalformedURLException e) {return null;}

		return tmp;
	}

//---- more code ---
	public void drawTile(int i,int j){
	Rectangle dr,sr;
	Image temp;
	Graphics tg;

		sr = new Rectangle(
			width*i/size,		height*j/size,
			width*(i+1)/size,	height*(j+1)/size);

		dr = map[i][j].showRect(sr);

		temp = createImage(sr.width,sr.height);
		tg = temp.getGraphics();

		tg.drawImage(draw,-sr.x,-sr.y,this);
		offG.drawImage(temp,sr.x,sr.y,this);
		

		/*offG.drawImage(draw,
			dr.x,dr.y,dr.width,dr.height,
			sr.x,sr.y,sr.width,sr.height,	this);

		dr = map[i][j].hideRect(sr);
		offG.drawImage(hide,
			dr.x,dr.y,dr.width,dr.height,
			0,0,hide.getWidth(this),hide.getHeight(this),	this);*/
	}

}