/* Simulation of a CarWash */
/* coding:  Holger Uhlig   */
/*          20.1.1997      */
/* changed: 16.4.1997      */

import java.awt.*;
import java.lang.*;
import java.net.URL;

/* class to store events sorted by time-index */
class EventList extends java.lang.Object {
  int eNr;
  float eTime;
  EventList next;
  
  public EventList (float eventTime) {
    eNr=0;
    eTime=eventTime;
    next=null;
  }

  /* insert event into list */
  public void insertEvent (int eventNr, float eventTime) {
    EventList hEL;
    if (eventTime <= eTime) 
      if (next == null) {
                         next=new EventList(eventTime);
                         next.eNr=eventNr;
                         next.next=null;
                        }
      else
        if (eventTime < next.eTime) next.insertEvent(eventNr, eventTime);
        else {
              hEL=next;
              next=new EventList(eventTime);
              next.eNr=eventNr;
              next.next=hEL;
             }
    else {
          hEL=next;
          next=new EventList(eTime);
          next.eNr=eNr;
          next.next=hEL;
          eNr=eventNr;
          eTime=eventTime;
         }
  }

  /* get event with next time-index */
  public EventList nextEvent () {
    EventList hEL1;
    EventList hEL2;
    hEL1=this;
    hEL2=this;
    while (hEL1.next != null) {
                               hEL2=hEL1;
                               hEL1=hEL1.next;
                              }
    hEL2.next=null;
    return hEL1;
  }

}

/* class to show animations */
class AnimationPanel extends java.awt.Panel {
  Graphics backGraphics;
  Graphics carWashFrontGraphics;
  Image backImage;
  Image carWashImage;
  Image carWashFrontImage;
  Image carImage;
  Image wheelImage[];
  MediaTracker tracker1;
  boolean animationOn;

  public AnimationPanel (SimCarWash parent) {
    backImage=parent.createImage(533, 247);
    backGraphics=backImage.getGraphics();
    backGraphics.drawString("loading images", 100, 100);
    repaint();
    tracker1=new MediaTracker(this);
    carWashImage=parent.getImage(parent.getDocumentBase(), "CARWASH.GIF");
    tracker1.addImage (carWashImage, 0);
    carImage=parent.getImage(parent.getDocumentBase(), "CAR.GIF");
    tracker1.addImage (carImage, 0);
    wheelImage=new Image[4];
    for (int i=0; i<4; i++) {
      wheelImage[i]=parent.getImage(parent.getDocumentBase(), "WHEEL"+i+".GIF");
      tracker1.addImage (wheelImage[i], 0);
    }
    try {tracker1.waitForAll();}
    catch (InterruptedException e) { };
    backGraphics.clearRect(0, 0, 533, 247);
    if (tracker1.isErrorAny()) {
				animationOn=false;
                                backGraphics.drawString("animation not available", 100, 100);
                               }
    else {
	  animationOn=true;
          backGraphics.drawImage(carWashImage, 0, 0, this);
         }
    repaint();
    carWashFrontImage=parent.createImage(512, 247);
    carWashFrontGraphics=carWashFrontImage.getGraphics();
    carWashFrontGraphics.drawImage(carWashImage, 0, 0, this);
    carWashFrontGraphics.dispose();
  }
 
  /* show animation of car arriving at carwash */
  public void carToCarWash (long frameTime) {
    if (animationOn) {
      backGraphics.clearRect(0, 0, 533, 247);
      backGraphics.drawImage(carWashImage, 472, 0, this);
      for (int i=0; i<10; i++) {
        backGraphics.clearRect(-361+(i*40), 112, 394, 125);
        backGraphics.drawImage(carImage, -321+(i*40), 112, this);
        backGraphics.drawImage(wheelImage[i % 4], -321+70+(i*40), 184, this);
        backGraphics.drawImage(wheelImage[i % 4], -321+291+(i*40), 184, this);
        repaint();
        pause(frameTime);
      }
    }
    else pause(10*frameTime);
  }
  
  /* show animation of car going into carwash */
  public void carInCarWash (long frameTime) {
    if (animationOn) {
      backGraphics.clearRect(0, 0, 533, 247);
      backGraphics.drawImage(carImage, 39, 112, this);
      for (int i=0; i<12; i++) {
        backGraphics.drawImage(wheelImage[i % 4], 109, 184, this);
        backGraphics.drawImage(wheelImage[i % 4], 330, 184, this);
        backGraphics.drawImage(carWashImage, 472-(i*40), 0, this);
        repaint();
        pause(frameTime);
      }
    }
    else pause(12*frameTime);
  }

  /* show animation of car arriving at end of waiting queue */
  public void carToCar (long frameTime) {
    if (animationOn) {
      backGraphics.clearRect(0, 0, 533, 247);
      backGraphics.drawImage(carImage, 472, 112, this);
      for (int i=0; i<10; i++) {
        backGraphics.clearRect(-361+(i*40), 112, 394, 125);
        backGraphics.drawImage(carImage, -321+(i*40), 112, this);
        backGraphics.drawImage(wheelImage[i % 4], -321+70+(i*40), 184, this);
        backGraphics.drawImage(wheelImage[i % 4], -321+291+(i*40), 184, this);
        repaint();
        pause(frameTime);
      }
    }
    else pause(10*frameTime);
  }

  /* show animation of car leaving carwash */
  public void carOffCarWash (long frameTime) {
    if (animationOn) {
      backGraphics.clearRect(0, 0, 533, 247);
      for (int i=0; i<29; i++) {
        backGraphics.clearRect(-361+(i*40), 112, 394, 125);
        backGraphics.drawImage(carWashImage, -472, 0, this);
        backGraphics.drawImage(carImage, -321+(i*40), 112, this);
        backGraphics.drawImage(wheelImage[i %4], -321+70+(i*40), 184, this);
        backGraphics.drawImage(wheelImage[i %4], -321+291+(i*40), 184, this);
        backGraphics.drawImage(carWashFrontImage, -472, 0, this);
        repaint();
        pause(frameTime);
      }
    }
    else pause(29*frameTime);
  }

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

  public void pause (long duration) {
    try { Thread.sleep(duration); }
    catch (InterruptedException e) { }
  }

  public void paint (Graphics g) {
    g.drawImage(backImage, (size().width-533)/2, (size().height-247)/2, this);
  }

}

/* class to show Pictogram of waitingQueue */
class PictogramPanel extends java.awt.Panel {
  Graphics backGraphics;
  Image backImage;
  Image pictoImage[];
  MediaTracker tracker1;
  boolean animationOn;

  public PictogramPanel (SimCarWash parent){
    backImage=parent.createImage(533, 26);
    backGraphics=backImage.getGraphics();
    tracker1=new MediaTracker(this);
    pictoImage=new Image[3];
    for (int i=1; i<4; i++) {
      pictoImage[i-1]=parent.getImage(parent.getDocumentBase(), "PICTO"+i+".GIF");
      tracker1.addImage (pictoImage[i-1], 0);
    }
    try {tracker1.waitForAll();}
    catch (InterruptedException e) { };
    if (tracker1.isErrorAny()) {
                                animationOn=false;
                                backGraphics.drawString("pictogram not available", 100, 10);
                               }
    else {
          animationOn=true;
         }
    repaint();
  }

  public void drawCarPictogram (int position, int number) {
    backGraphics.drawImage (pictoImage[0], 477-position*53, 7, this);
    backGraphics.setXORMode (Color.white);
    String numberStr=number+"";
    backGraphics.drawString (numberStr, 501-position*53-(backGraphics.getFontMetrics().stringWidth(numberStr)/2), 18);
    backGraphics.setPaintMode ();
  }

  public void drawPictogram (int carCount, boolean busy) {
    if (animationOn) {
      backGraphics.clearRect (0, 0, 533, 26);
      backGraphics.fillRect (477, 3, 533, 22);
      if (busy) backGraphics.drawImage (pictoImage[1], 480, 7, this);
      if (carCount<10) {
        for (int i=1; i<=carCount; i++) drawCarPictogram(i, i);
                              }
      else {
        for (int i=1; i<5; i++) drawCarPictogram(i, i);
        backGraphics.drawImage (pictoImage[2], 212, 7, this);
        for (int i=6; i<10; i++) drawCarPictogram(i, carCount-9+i);
             }
      repaint();
    }
  }

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

  public void paint (Graphics g) {
    g.drawImage(backImage, (size().width-533)/2, (size().height-26)/2, this);
  }

}

/* main class - simulation of carwash */
public class SimCarWash extends java.applet.Applet implements Runnable {
  AnimationPanel panel1;
  PictogramPanel panel3;
  Panel panel2;
  Panel panel4;
  Button button1;
  Choice choice1;
  TextField textf1;
  TextField textf2;
  TextField textf3;
  Thread simulation;
  float simduration;
  float arrivingRate;
  float washingRate;
  float throuput;
  EventList eventList1;
  int waitingCars;
  int washedCars;
  int speed;
  boolean carWashBusy;
  float simTime;
  Label label1;
  Label label2;
  Label label3;
    
  public void init () {
    this.setLayout (new BorderLayout ());
    panel1=new AnimationPanel(this);
    panel1.setLayout (new GridLayout (1, 1, 0, 0));
    panel3=new PictogramPanel(this);
    panel3.setLayout (new GridLayout (1, 1, 0, 0));
    panel4=new Panel();
    panel4.setLayout (new GridLayout(2, 1, 0, 0));
    panel4.add (new Label("CarWash - Simulation", Label.CENTER));
    panel4.add (panel3);
    add ("North", panel4);
    add ("Center", panel1);
    panel2=new Panel();
    panel2.setLayout (new GridLayout (7, 2));
    button1=new Button("Start");
    choice1=new Choice();
    choice1.addItem("realtime");
    choice1.addItem("doublespeed");
    choice1.addItem("quadspeed");
    choice1.addItem("fullspeed");
    simduration=1;
    arrivingRate=8;
    washingRate=8;
    speed=1;
    textf1=new TextField (""+simduration);
    textf2=new TextField (""+arrivingRate);
    textf3=new TextField (""+washingRate);
    label1=new Label("0 cars", Label.RIGHT);
    label2=new Label("0 cars/min", Label.RIGHT);
    label3=new Label("0 cars", Label.RIGHT);
    panel2.add (button1);
    panel2.add (choice1);
    panel2.add (new Label("simulationtime (hours):"));
    panel2.add (textf1);
    panel2.add (new Label("arrivingrate (cars/min):"));
    panel2.add (textf2);
    panel2.add (new Label("washingrate (cars/min):"));
    panel2.add (textf3);
    panel2.add (new Label("washed cars:"));
    panel2.add (label1);
    panel2.add (new Label("throuput:"));
    panel2.add (label2);
    panel2.add (new Label("waiting cars:"));
    panel2.add (label3);
    add ("South", panel2);
  }

  /* create exponential distributed number */
  public float exponDistributed (float lambda) {
    return ((float)(-(1/lambda)*Math.log(Math.random())));
  }
 
  public void stop () {
   if (simulation != null) {
                            simulation.stop();
                            simulation=null;
		       button1.setLabel("Start");
                           }
  }

  public void pause (long duration) {
    try { Thread.sleep(duration); }
    catch (InterruptedException e) { }
  }

  /* simulation run */
  public void run () {
    int frames=1;
    int animation=1;
    float restTime;
    float animTime;
    float frameTime;
    try {simduration=new Float(textf1.getText()).floatValue();}
    catch (NumberFormatException e1) {}
    textf1.setText(""+simduration);
    try {arrivingRate=new Float(textf2.getText()).floatValue();}
    catch (NumberFormatException e1) {}
    textf2.setText(""+arrivingRate);
    try {washingRate=new Float(textf3.getText()).floatValue();}
    catch (NumberFormatException e1) {}
    textf3.setText(""+washingRate);
    simTime=0;
    waitingCars=0;
    washedCars=0;
    throuput=0;
    label1.setText(washedCars+" cars");
    label2.setText(throuput+" cars/min");
    label3.setText(waitingCars+" cars");
    carWashBusy=false;
    eventList1=new EventList(simduration*60);
    eventList1.insertEvent(1, exponDistributed(arrivingRate));
    EventList cEvent=eventList1.nextEvent();
    restTime=cEvent.eTime;
    panel3.drawPictogram(waitingCars, carWashBusy);
    while (cEvent.eNr != 0) {
      if (speed != 0) pause ((long)restTime);
      else pause (10);
      simTime=cEvent.eTime;
      switch (cEvent.eNr) {
       case 1: if (carWashBusy) {
                                 frames=10;
                                 if (waitingCars == 0) animation=2;
                                 else animation=3;
                                 waitingCars++;
                                }
               else {
                     carWashBusy=true;
                     eventList1.insertEvent(2, simTime+exponDistributed(washingRate));
                     frames=22;
                     animation=1;
                    }
               eventList1.insertEvent(1, simTime+exponDistributed(arrivingRate));
               break;
       case 2: if (waitingCars == 0) {
                                      carWashBusy=false;
                                      frames=31;
                                      animation=4;
                                     }
               else {
                     waitingCars--;
                     eventList1.insertEvent(2, simTime+exponDistributed(washingRate));
                     frames=41;
                     animation=5;
                    }
               washedCars++;
               throuput=washedCars/simTime;
               break;
      }
      cEvent=eventList1.nextEvent();
      if (speed != 0) animTime=(cEvent.eTime-simTime)*60000/speed;
      else animTime=0;
      frameTime=animTime/frames;
      if (frameTime>100) {
			  frameTime=100;
                          restTime=animTime-(frameTime*frames);
                         }
      else restTime=0;
      if (frameTime<10) restTime=animTime;
      else {switch (animation) {
              case 1: panel1.carToCarWash((long)frameTime);
                      panel1.carInCarWash((long)frameTime);
                      break;
              case 2: panel1.carToCarWash((long)frameTime);
                      break;
              case 3: panel1.carToCar((long)frameTime);
                      break;
              case 4: panel1.carOffCarWash((long)frameTime);
                      break;
              case 5: panel1.carOffCarWash((long)frameTime);
                      panel1.carInCarWash((long)frameTime);
                      break;
           }
                                     }
      label1.setText(washedCars+" cars");
      label2.setText(throuput+" cars/min");
      label3.setText(waitingCars+" cars");
      panel3.drawPictogram(waitingCars, carWashBusy);
                         }
    button1.setLabel("Start");
  }

  public boolean action (Event e, Object arg) {
    if (e.target == button1) {
      if (button1.getLabel() == "Start") {
        if (simulation != null) {
                                 simulation.stop();
                                 simulation=null;
                                }
        simulation=new Thread(this);
        simulation.start();
        button1.setLabel("Stop");
      }
      else {
            simulation.stop();
            simulation=null;
            button1.setLabel("Start");
           }
      return true;
    }
    if (e.target == choice1) {
                              switch (choice1.getSelectedIndex()) {
                                case 0: speed=1;
                                        break;
                                case 1: speed=2;
                                        break;
                                case 2: speed=4;
                                        break;
                                case 3: speed=0;
                                        break;
                              }
                              return true;
                             }
    return false;
  }
}