//: c17:GameEnvironment.java
// From Thinking in Java, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// An example of the Abstract Factory pattern

interface Obstacle {
  void action();
}

interface Player {
  void interactWith(Obstacle o);
}

class Kitty implements Player {
  public void interactWith(Obstacle ob) {
    System.out.print("Kitty has encountered a ");
    ob.action();
  }
}

class KungFuGuy implements Player {
  public void interactWith(Obstacle ob) {
    System.out.print("KungFuGuy now battles a ");
    ob.action();
  }
}

class Puzzle implements Obstacle {
  public void action() { 
    System.out.println("Puzzle"); 
  }
}

class NastyWeapon implements Obstacle {
  public void action() { 
    System.out.println("NastyWeapon"); 
  }
}

// The Abstract Factory:
interface GameElementFactory {
  Player makePlayer();
  Obstacle makeObstacle();
}

// Concrete factories:
class KittiesAndPuzzles 
implements GameElementFactory {
  public Player makePlayer() { 
    return new Kitty();
  }
  public Obstacle makeObstacle() {
    return new Puzzle();
  }
}

class KillAndDismember 
implements GameElementFactory {
  public Player makePlayer() { 
    return new KungFuGuy();
  }
  public Obstacle makeObstacle() {
    return new NastyWeapon();
  }
}

public class GameEnvironment {
  private GameElementFactory gef;
  private Player p;
  private Obstacle ob;
  public GameEnvironment(
    GameElementFactory factory) {
    gef = factory;
    p = factory.makePlayer(); 
    ob = factory.makeObstacle();
  }
  public void play() {
    p.interactWith(ob);
  }
  public static void main(String args[]) {
    GameElementFactory
      kp = new KittiesAndPuzzles(),
      kd = new KillAndDismember();
    GameEnvironment 
      g1 = new GameEnvironment(kp),
      g2 = new GameEnvironment(kd);
    g1.play();
    g2.play();
  }
} ///:~