/*beads.java
Sieuwert van Otterloo
smotterl@cs.uu.nl
go.to/sieuwert
March 2000

A mind game where the user must 
move colored disks around until all are
in their own position.*/

import java.awt.*;

class bead{
 Color c,opposite;//it's color
 int rad;//painted size
 int num;//the number it has
 int x, y;//it's position
 
 bead(int i,float tot){
  rad=17-(int)tot/3;
  num=i;
  c=Color.getHSBColor((float)(i/tot),1,1);
  if(c.getRed()+2*c.getGreen()+c.getBlue()>512)
    opposite=Color.black;
  else
    opposite=Color.white;
 } 
 
 void set(int a,int b)
 /*move this bead to given position*/
    {x=a;y=b;}

 void paint(Graphics g){
 //paint this bead
  g.setColor(c);
  circle(g,x,y,rad);
  g.setColor(opposite);
  g.drawString(""+num,x-5,y+5);
 }
 
 static void circle(Graphics g,int i,int j,int rd)
 //draw a filled circle
    {g.fillOval(i-rd,j-rd,2*rd,2*rd);}
}

public class beads extends java.applet.Applet{
 int B;/*total number of beads*/
 int[] posx;/*horizontal position of beads*/
 int[] posy;/*vertical position of beads*/
 bead[] b;/*the beads*/
 Color[] backcolor;/*colors of the large circles*/
 boolean restart;
 Font font=new Font("Arial",Font.BOLD,14);
 int movecounter;/*the number of moves done*/
 long timer;/*number of seconds user is buzy*/
 int[] letterx,lettery;
  
 public void init(){
  setBackground(Color.white);
  shuffle(5);
  /*the puzzle starts with 5 beads. If solved,
  it becomes harder.*/
 }

 void shuffle(int total){
 /*sets up a new game. total becomes the new number
 of beads.*/   
  B=total;
  if(B>17)
    B=17; //13 is maximum value
  backcolor=new Color[B];
  for(int i=0;i<B;i++){
   backcolor[i]=Color.getHSBColor(i/(float)B,1,1);
  }
  setpos();  
  //make new beads:
  b=new bead[B];
  for(int i=0;i<B;i++)
   b[i]=new bead(i,B);
  //do moves to unsolve the puzzle
  for(int i=0;i<5*B+3;i++)
    move((int)(Math.random()*B));    
  restart=false;
  movecounter=0;
  //get time to calculate the users time later
  timer=System.currentTimeMillis()/1000;
 }
 
 void setpos(){
 //calculate positions of beads
  posx=new int[B];
  posy=new int[B];
  //letter refers to inner circle of numbers
  letterx=new int[B];
  lettery=new int[B];
  int radius=90+3*B;//radius of big circle
  int letterradius=radius-40;
  double ang;
  for(int i=0;i<B;i++){
   ang=i*2.0*Math.PI/B;
   posx[i]=getx(radius,ang);  
   posy[i]=gety(radius,ang); 
   letterx[i]=getx(letterradius,ang);  
   lettery[i]=gety(letterradius,ang);  
  }
  
 }
 int getx(double radius,double angle)
    {return (int)(170+Math.sin(angle)*radius);}
 int gety(double radius,double angle)
    {return (int)(170-Math.cos(angle)*radius);}

 public boolean mouseDown(Event ev,int x,int y){
  //called if user clicked somewhere
  //restart is set if user solved puzzle:
  //make a bigger puzzle
  if(restart)
    shuffle(B+2);
  //find closest bead to point:
  int dist=distance(b[0],x,y);
  int argmin=0;
  for(int i=1;i<B;i++)  
   if(distance(b[i],x,y)<dist){
    dist=distance(b[i],x,y);
    argmin=i;
   }	
  //if close enough, do a move: 
  if(dist<30)
	move(argmin);
  return true;
 }  
 int distance(bead bd,int x,int y){
 /*return pythagoras distance in pixels of bead to a point*/
  return (int) Math.sqrt((bd.x-x)*(bd.x-x)+(bd.y-y)*(bd.y-y));
 }

 void move(int i){
 /*swap the neighbours of this bead.*/
  swap(m(i-1),m(i+1));
  places();
  repaint();
  movecounter++;
 } 
 void swap(int m,int n){
 /*swap beads m and n*/
  bead swp=b[m];
  b[m]=b[n];
  b[n]=swp;    
 }
 
 int m(int i)
 /*make i a number between 0 and B*/
  {return (i+B)%B;}

void places(){
 /*tell every bead its new position. Call this method
 every time you shuffled the beads*/
  for(int i=0;i<B;i++)
   b[i].set(posx[i],posy[i]);
 }

 public void paint(Graphics g){
 /*paint the screen*/   
  g.setFont(font);
  g.drawPolygon(posx,posy,B);
  for(int i=0;i<B;i++){
   //large circles:
   g.setColor(backcolor[i]);
   bead.circle(g,posx[i],posy[i],35-B);
   g.setColor(Color.white);
   bead.circle(g,posx[i],posy[i],23-B/2);   
   //inner numbers
   g.setColor(Color.black);
   g.drawString(""+i,letterx[i]-5,lettery[i]+5);   
   //small circles:
   b[i].paint(g);
  }
  
  if(solved()){
  /*If the user solved the puzzle,
  display nice message, and toggle restart.
  The next time the user clicks, a new puzzle appears*/
   g.setColor(Color.black);
   int texth=165;
   g.drawString("Congratulations!",120,texth);
   g.drawString(movecounter+" moves",120,texth+20);   
   g.drawString((System.currentTimeMillis()/1000-timer)
                +" seconds",120,texth+40);   
   restart=true;
  }
 } 
 
 boolean solved(){
 //check wether all beads are in place
  for(int i=0;i<B;i++)
   if(b[i].num!=i)
    return false;
  return true;
 }

}