import java.awt.*;
import java.awt.event.*;
import java.awt.Graphics;
import javax.swing.*;
import java.rmi.*;
import java.rmi.server.*;

class hrdisplay extends JFrame  // graphics class
{
  public  int FRAMEDELAY = 50;
  private Graphics brush;
  public  Graphics display;
  private Image canvas;    // off-screen graphics buffer
  private Image background; // racing background gif
  private Image staticbkgrd; // static (stretched) background;
  private Image racergif;    // horse and rider animated gif
  public int HN = 3;       // number of horses
  public int TW = 800; // track length;
  public int TH;   // track height - depends on number of racers
  public int LW = 60;  // lane width    
  public byte id;  // my id in the race
  public horse[] H;    // information for all horses

  public dhrclient mydhr; // pointer to dhr synchronization manager

  public void paint(Graphics g) {}  // overrides auto-update

  public void init(String[] args)
    {
    try
    {
       TH = (this.HN * this.LW) + this.LW+10;
       setBounds(0,0,TW,TH);
       setVisible(true);
       background = Toolkit.getDefaultToolkit().getImage("hrbackground.gif");
       prepareImage(background,this);
       racergif = Toolkit.getDefaultToolkit().getImage("racer.gif");
       prepareImage(racergif,this);
       canvas = createImage(TW,TH);
       staticbkgrd = createImage(TW,TH);
       brush = canvas.getGraphics();  // to double buffer
       brush.setColor(Color.blue);   
       display = this.getGraphics(); // to screen
       try { Thread.sleep(750); } catch (InterruptedException IE) {}
       staticbkgrd.getGraphics().drawImage(background,0,0,TW,TH-30,null);
       resetbackground();
       displayStatus("waiting for other racers ...");
       display.drawImage(canvas,0,0,null);  // draws to screen
       race();
    } catch (Exception e) {System.out.println(e);}
    } // init

   public int randint(int min, int max) 
    { return (int) (Math.random() * (max-min+1) + min); }

   private void resetbackground()
    { 
       brush.drawImage(staticbkgrd,0,30,null);
       // draw track lines
       brush.setColor(Color.blue);   
       for(int i=1;i<=HN+1;i++)
	   { brush.drawLine(0,(i*LW)-5,TW-1,(i*LW)-5); }
       // finish line:
       brush.setColor(Color.red);   
       brush.drawLine(TW-15,0,TW-15,TH-1);  // finish line
    } // resetbackground

   public void nextframe(int delay) // delay in ms
    {
       try { Thread.sleep(delay); } catch (InterruptedException IE) {}
       display.drawImage(canvas,0,0,null);  // draws to screen
       resetbackground();
    } // nextframe with ms delay

   public void displayStatus(String message)
    {
	Font oldfont = brush.getFont();
	brush.setFont(new Font("Serif",Font.BOLD,24));
	brush.drawString(message,TW/3,LW-10);
	brush.setFont(oldfont);
    }


    public void draw(horse racer)
    {
	if (racer==null || (!racer.inrace)) return;
	brush.setColor(Color.black);
	brush.drawString(racer.name,10,(racer.y+55));
	brush.drawImage(racergif,racer.x,racer.y,null);
    }

   boolean stoprace = false;
   public void race() throws Exception
    {
        int i; // loop counter
        stoprace = false;
        int winner;
        for(i=0;i<HN;i++) draw(H[i]);
        nextframe(400);

        // initial block to wait for everyone to join race
	mydhr.block();
	mydhr.initialization = false;
	Thread.sleep(200);
	for(i=0;i<HN;i++) 
	    { if (H[i]==null) System.out.println(i+" is null"); }

	System.out.println("starting race");
        while (!stoprace) 
        {
          for(i=0;i<HN;i++) draw(H[i]);
          nextframe(FRAMEDELAY);
          winner = determineLeader(H);
          if (winner==-1) displayStatus("It's a tie!");
          else displayStatus("The leader is "+H[winner].name);

	  // move forward, then block until passpermit called.
	  H[id].x += randint(1,5);
	  mydhr.block();
	  if (!H[id].inrace) stoprace = true;
        } // main while loop
    } // race

    public int determineLeader(horse[] H)  //return lead index, -1 if tie
    {   
        int i, lead, winner;
        lead = H[0].x;  winner = 0; 
        for(i=1;i<H.length;i++)
            {
              if (H[i].x > lead)
                { lead = H[i].x; winner = i; }
              else
              if (H[i].x == lead) winner = -1;
	      if (H[i].x > TW-68) stoprace = true;  // stops race
            } // for loop
        return winner;
    } // determineLeader

} // class hrdisplay


//////////////////////////////////////////////////////////////////////


public class dhrclient extends UnicastRemoteObject implements dhr
{
    long localseq = 0;
    hrdisplay localrace;
    dhr neighbor;
    boolean initialization = true;
    static raceinfo localinfo;

    public dhrclient() throws RemoteException {}

    //called remotely:
    public synchronized void passpermit(raceinfo ri) throws RemoteException
    {
	localseq = ri.seq;
	if (ri.horses[localrace.id] == null)
	    ri.horses[localrace.id] = localrace.H[localrace.id]; // join race
	localrace.H = ri.horses;  // update info
	//System.out.println("passpermit call accepted, notifying...");
	notify();
    }
    
    public synchronized void block() throws Exception
    {
	localinfo.horses = localrace.H;
	localinfo.seq += 1;
	//System.out.println("preparing to call passpermit from block()");
	if (localrace.id!=0) initialization = false;
	if (!initialization || localrace.id==0)
	    {
  	      neighbor.passpermit(localinfo);
	      //System.out.println("after passpermit returned; from block()");
	    }
	wait();
    }

    // args[0] is name of horse, args[1] is number of racers,
    // args[2] horse id, args[3] is neighbor ip, and args[4] is self ip
    // and args[5] is delaytime (not so critical this time)
  public static void main(String[] args) throws Exception
  {
	
       	System.setProperty("java.security.policy",
			   "server.policy");
	System.setSecurityManager(
	     new RMISecurityManager());

    hrdisplay session  = new hrdisplay();
    if (args.length>5) session.FRAMEDELAY = Integer.parseInt(args[5]);
    session.HN = Integer.parseInt(args[1]); // number of horses in race
    session.H = new horse[session.HN]; // create empty array
    session.id = (byte)Integer.parseInt(args[2]);
    // make local horse object
    session.H[session.id] = 
	new horse(true,0,(session.id*session.LW)+session.LW,args[0]);

    dhrclient me = new dhrclient();
    me.localrace = session;
    session.mydhr = me;
    me.localinfo = new raceinfo(session.H);

    // bind me to local registry:
    Naming.rebind("//"+args[4]+"/dhracer",me); // change to your real ip

    // lookup neighbor racer
    // loop needed because initially nobody's bound:
         boolean tryagain = true;
	 System.out.println("finding neighbor ...");
         while (tryagain || me.neighbor==null)
	  {  try 
             {
	       me.neighbor = (dhr)Naming.lookup("//"+args[3]+"/dhracer");
	       tryagain = false;
	     } catch (Exception ie)   { tryagain = true;}
	  }  

    session.addWindowListener(new WindowAdapter() {
              public void windowClosing(WindowEvent e) {System.exit(0);} });
    System.out.println("initializing race");
    session.init(args);
    Naming.unbind("//127.0.0.1/dhracer"); // invalidate bind
  } // main

} // dhrclient