package lab;

import static java.lang.System.out;

public class ChrismasTreeDemo {
    public static void main (String[] args) {
        ChrismasTreeComponent t =
            new Gift( new Bell( new Candy(new ChrismasTree()) ) );
        t.sing();
    }
}

abstract class ChrismasTreeComponent {
    abstract public void sing();
}

class ChrismasTree extends ChrismasTreeComponent {
    @Override
    public void sing() {
        out.println("I am a Chrismas tree");
    }
}

abstract class ChrismasTreeDecorator extends ChrismasTreeComponent {

    ChrismasTreeComponent c;

    public ChrismasTreeDecorator(ChrismasTreeComponent c) {
        this.c = c;
    }
    @Override
    public void sing() {
        this.decoratorsSing();
        out.print(", ");
        c.sing();
    }
    abstract void decoratorsSing();
}

class Bell extends ChrismasTreeDecorator {
    public Bell(ChrismasTreeComponent c) {
        super(c);
    }

    @Override
    void decoratorsSing() {
        out.print("I have a bell");
    }
}

class Candy extends ChrismasTreeDecorator {
    public Candy(ChrismasTreeComponent c) {
        super(c);
    }
    @Override
    void decoratorsSing() {
        out.print("I have a bell");
    }
}

class Gift extends ChrismasTreeDecorator {
    public Gift(ChrismasTreeComponent c) {
        super(c);
    }
    @Override
    void decoratorsSing() {
        out.print("I have a gift");
    }
}