/*
--- CSU213 Fall 2006 Lecture Notes ---------
Copyright 2006 Viera K. Proulx

Lecture 12: October 2, 2006
Part 1: Using Libraries
*/

import draw.*;
import colors.*;
import geometry.*;
import java.util.Random;

/*
                 +------------------------+                    
                 | LoStars                |<------------------+
                 +------------------------+                   |
                 +------------------------+                   |
                 | LoStars moveFixed()    |                   |
                 | LoStars move()         |                   |
                 | boolean draw(Canvas x) |                   |
                 +------------------------+                   |
                             |                                |
                            / \                               |
                            ---                               |
                             |                                |
              -------------------------------                 |
              |                             |                 |
  +------------------------+    +------------------------+    |
  | MTLoStars              |    | ConsLoStars            |    |
  +------------------------+    +------------------------+    |
  +------------------------+  +-| Star first             |    |
  | LoStars moveFixed()    |  | | LoStars rest           |-+  |
  | LoStars move()         |  | +------------------------+ |  |
  | boolean draw(Canvas x) |  | | LoStars moveFixed()    | |  |
  +------------------------+  | | LoStars move()         | |  |
                              | | boolean draw(Canvas x) | |  |
                              | +------------------------+ |  |
                              |                            |  |
                              |                            +--+
                              v
                  +------------------------+
                  | Star                   |
                  +------------------------+
                  | Posn loc               |
                  | int lifespan           |
                  +------------------------+
                  | Star moveFixed()       |
                  | Star move()            |
                  | boolean draw(Canvas c) |
                  | int randomX()          |
                  | int randomY()          |
                  +------------------------+


*/

//-------------------------------------------------------------------------
//-------------------------------------------------------------------------
// to represent a shooting star
class Star {
  Posn loc;
  int lifespan;

  Star(Posn loc, int lifespan) {
    this.loc = loc;
    this.lifespan = lifespan;
  }

  // move this star down 3 pixels if alive, 4 pixels if burned
  Star moveFixed(){
    if (lifespan > 0)
      return new Star(new Posn(this.loc.x, 
                               this.loc.y + 3), 
                               this.lifespan - 1);
    else
      return new Star(new Posn(this.loc.x, 
                               this.loc.y + 4), 
                               this.lifespan);
  }

  // move this star down
  Star move(){
    if (lifespan > 0)
      return new Star(new Posn(this.loc.x + this.randomX(), 
                               this.loc.y + this.randomY()), 
                               this.lifespan - 1);
    else
      return new Star(new Posn(this.loc.x, 
                               this.loc.y + 4), 
                               this.lifespan);
  }

  // draw this star on the given canvas
  boolean draw(Canvas c){
    if (this.lifespan > 0)
      return c.drawDisk(this.loc, 4, new White());
    else
      return c.drawDisk(this.loc, 3, new Black());
  }

    // produce a random distance to move left or right
  int randomX(){
    return 2 - new Random().nextInt() % 5;
  }

    // produce a random distance to fall down
  int randomY(){
    return new Random().nextInt() % 5;
  }
}


//-------------------------------------------------------------------------
//-------------------------------------------------------------------------
// to represent shooting stars in our world
interface LoStars {
  // move the stars  in this list down a fixed distance
  LoStars moveFixed();

  // move the stars  in this list down
  LoStars move();

  // draw the stars in this list
  boolean draw(Canvas x);
}

//-------------------------------------------------------------------------
//-------------------------------------------------------------------------
// to represent an empty list of stars
class MTLoStars implements LoStars {

  MTLoStars() {
  }

  // move the stars  in this list down a fixed distance
  LoStars moveFixed() {
    return this;
  }

  // move the stars  in this list down
  LoStars move() {
    return this;
  }

  // draw the stars in this list
  boolean draw(Canvas x) {
    return true;
  }

}

//-------------------------------------------------------------------------
//-------------------------------------------------------------------------
// to represent a nonempty list of stars
class ConsLoStars implements LoStars {
  Star first;
  LoStars rest;

  ConsLoStars(Star first, LoStars rest) {
    this.first = first;
    this.rest = rest;
  }

/*
  // ** DRAFT TEMPLATE ** Edit as needed.
  LoStars move() {
    ... this.first ...
    ... this.rest.move(...) ...
    ... this.rest.draw(...) ...
  }
*/

  // move the stars  in this list down a fixed distance
  LoStars moveFixed() {
    return new ConsLoStars(this.first.moveFixed(),
                           this.rest.moveFixed());
  }

  // move the stars  in this list down
  LoStars move() {
    return new ConsLoStars(this.first.move(),
                           this.rest.move());
  }

  // draw the stars in this list
  boolean draw(Canvas c) {
    return this.first.draw(c) &&
           this.rest.draw(c);
  }

}

//-------------------------------------------------------------------------
//-------------------------------------------------------------------------
// the world of shooting stars
class StarWorld extends World{
  LoStars stars;

  StarWorld(LoStars stars){
    this.stars = stars;
  }

  World onTick(){
    return new StarWorld(this.stars.move());
  }

  World onKeyEvent(String ke){
    return this;
  }

  boolean draw(){
    return theCanvas.drawRect(new Posn(0, 0), 200, 300, new Blue()) &&
           this.stars.draw(this.theCanvas);
  }

  boolean erase(){
    return theCanvas.drawRect(new Posn(0, 0), 200, 300, new Blue());
  }
}

class Examples{
  Examples() {}

  Star s1 = new Star(new Posn(30, 0), 30);
  Star s2 = new Star(new Posn(40, 10), 20);
  Star s3 = new Star(new Posn(70, 20), 40);
  Star s4 = new Star(new Posn(50, 60), 20);
  Star s5 = new Star(new Posn(80, 30), 40);
  Star s6 = new Star(new Posn(20, 20), 50);
  Star s7 = new Star(new Posn(40, 40), 50);
  Star s8 = new Star(new Posn(70, 30), 30);
  Star s9 = new Star(new Posn(10, 40), 10);
  Star s10 = new Star(new Posn(60, 40), 20);
  Star burned = new Star(new Posn(60, 40), 0);

  LoStars mtstars = new MTLoStars();
  LoStars stars  = new ConsLoStars(this.s1,  
                   new ConsLoStars(this.s2,  
                   new ConsLoStars(this.s3,  
                   new ConsLoStars(this.s4,  
                   new ConsLoStars(this.s5,  
                   new ConsLoStars(this.s6,  
                   new ConsLoStars(this.s7,  
                   new ConsLoStars(this.s8,  
                   new ConsLoStars(this.s9,  
                   new ConsLoStars(this.s10, this.mtstars)))))))))); 

  LoStars starsx = new ConsLoStars(this.s1,  
                   new ConsLoStars(this.burned,  
                   new ConsLoStars(this.s3, this.mtstars))); 
 
  // test the method move in the class Star
  boolean testMoveFixedStar =     
    (check this.s1.moveFixed() expect new Star(new Posn(30, 3), 29)) &&
    (check this.burned.moveFixed() expect new Star(new Posn(60, 44), 0));


  // test the method move in the class LoStars
  boolean testMoveFixedLoStars =     
    (check this.mtstars.moveFixed() expect this.mtstars) &&
    (check this.starsx.moveFixed() 
        expect new ConsLoStars(new Star(new Posn(30, 3), 29),  
               new ConsLoStars(new Star(new Posn(60, 44), 0),  
               new ConsLoStars(new Star(new Posn(70, 23), 39), this.mtstars))));


  StarWorld sw = new StarWorld(this.stars);
  boolean go = sw.bigBang(200, 300, 0.1);
}