import draw.*;


class LightWorld extends World {

   Posn redCenter, yellowCenter, greenCenter;
   int height, width, radius;

   LightWorld(int width, int height) {
     this.height = height;
     this.width = width;
     this.radius = width/2;
     this.redCenter = new Posn(radius, (height/3 - radius));
     this.yellowCenter = new Posn(radius, (height/2));
     this.greenCenter = new Posn(radius, ((2 * height/3) + radius));
   }

   //Draws a traffic signal of the specified size. assumes that it's a vertical, not horizontal light
   boolean draw() {
     // redCenter ... yellowCenter ... greenCenter ... height ... width ... radius ... theCanvas
     return this.theCanvas.start(width,height) &&
     this.theCanvas.drawDisk(redCenter,radius,new Red()) &&
     this.theCanvas.drawCircle(yellowCenter,radius,new Yellow()) &&
     this.theCanvas.drawCircle(greenCenter,radius,new Green());
   }

   //To draw a Disk for the specified light, of the given color
   boolean On(Posn light, Color c) {
     // redCenter ... yellowCenter ... greenCenter ... height ... width ... radius ... theCanvas
     return this.theCanvas.drawDisk(light,radius,c);
   }
   
   //To color over the Disk at the specified light, and leave an outline of it's On color
   boolean Off(Posn light, Color c) {
     // redCenter ... yellowCenter ... greenCenter ... height ... width ... radius ... theCanvas
     return this.theCanvas.drawDisk(light,radius,new White()) &&
            this.theCanvas.drawCircle(light,radius,c);
   }

   // Methods to turn On and Off specific lights
   boolean redOn() { return On(redCenter, new Red()); }
   boolean redOff() { return Off(redCenter, new Red()); }
   boolean yellowOn() { return On(yellowCenter, new Yellow()); }
   boolean yellowOff() { return Off(yellowCenter, new Yellow()); }
   boolean greenOn() { return On(greenCenter, new Green()); }
   boolean greenOff() { return Off(greenCenter, new Green()); }

   //The following methods are used to make animations
   boolean erase() {
     return true;
   }
   World onKeyEvent(String key) {
     return this;
   }
   World onTick() {
     return this;
   }
}

class TrafficLight {
  boolean red, yellow, green;
  LightWorld trafficLight;

  TrafficLight() {
    this.red = true;
    this.yellow = false;
    this.green = false;
    this.trafficLight = new LightWorld(50,150);
  }

  //To display the traffic light graphically
  void displayLight() {
    this.trafficLight.draw();
  }
     
  //new TrafficLight().change() -> void
  // To change the lights in the US fashion for this TrafficLight
  // Note, will modify the booleans red, yellow, and green
  void change() {
    // this.red... this.yellow ... this.green ... trafficLight.LightWorldMethod()
    if (this.red) {
      this.red = false;
      this.trafficLight.redOff();
      this.green = true;
      this.trafficLight.greenOn();
    } else if (this.yellow) {
      this.red = true;
      this.trafficLight.redOn();
      this.yellow = false;
      this.trafficLight.yellowOff();
    } else {
      this.green = false;
      this.trafficLight.greenOff();
      this.yellow = true;
      this.trafficLight.yellowOn();
   } 
 }

  //new TrafficLight().change() -> void
  // To change the lights in the British fashion for this TrafficLight
  // Note, will modify the booleans red, yellow, and green
  void changeBritishStyle() {
    // this.red... this.yellow ... this.green ... this.trafficLight.LightWorldMethod() ...
    if (this.red && !this.yellow) {
      this.yellow = true;
      this.trafficLight.yellowOn();
    } else if (this.red && this.yellow) {
      this.red = false;
      this.trafficLight.redOff();
      this.yellow = false;
      this.trafficLight.yellowOff();
      this.green = true;
      this.trafficLight.greenOn();
    } else if (this.green && !this.yellow) {
      this.yellow = true;
      this.trafficLight.yellowOn();
    } else if (this.green && this.yellow) {
      this.green = false;
      this.trafficLight.greenOff();
    } else {
      this.red = true;
      this.trafficLight.redOn();
      this.yellow = false;
      this.trafficLight.yellowOff();
    }
  }

      
      

}