"""
Attach additional responsibilities to an object dynamically. Decorators
provide a flexible alternative to subclassing for extending
functionality.
"""

import abc


class Component(metaclass=abc.ABCMeta):
    """
    Define the interface for objects that can have responsibilities
    added to them dynamically.
    """

    @abc.abstractmethod
    def operation(self):
        pass


class Decorator(Component, metaclass=abc.ABCMeta):
    """
    Maintain a reference to a Component object and define an interface
    that conforms to Component's interface.
    """

    def __init__(self, component):
        self._component = component

    @abc.abstractmethod
    def operation(self):
        pass


class ConcreteDecoratorA(Decorator):
    """
    Add responsibilities to the component.
    """

    def operation(self):
        # ...
        self._component.operation()
        # ...


class ConcreteDecoratorB(Decorator):
    """
    Add responsibilities to the component.
    """

    def operation(self):
        # ...
        self._component.operation()
        # ...


class ConcreteComponent(Component):
    """
    Define an object to which additional responsibilities can be
    attached.
    """

    def operation(self):
        pass


def main():
    concrete_component = ConcreteComponent()
    concrete_decorator_a = ConcreteDecoratorA(concrete_component)
    concrete_decorator_b = ConcreteDecoratorB(concrete_decorator_a)
    concrete_decorator_b.operation()


if __name__ == "__main__":
    main()    	
    	

    	
    		
class Book {
    private $author;
    private $title;
    function __construct($title_in, $author_in) {
        $this->author = $author_in;
        $this->title  = $title_in;
    }
    function getAuthor() {
        return $this->author;
    }
    function getTitle() {
        return $this->title;
    }
    function getAuthorAndTitle() {
      return $this->getTitle().' by '.$this->getAuthor();
    }
}

class BookTitleDecorator {
    protected $book;
    protected $title;
    public function __construct(Book $book_in) {
        $this->book = $book_in;
        $this->resetTitle();
    }   
    //doing this so original object is not altered
    function resetTitle() {
        $this->title = $this->book->getTitle();
    }
    function showTitle() {
        return $this->title;
    }
}

class BookTitleExclaimDecorator extends BookTitleDecorator {
    private $btd;
    public function __construct(BookTitleDecorator $btd_in) {
        $this->btd = $btd_in;
    }
    function exclaimTitle() {
        $this->btd->title = "!" . $this->btd->title . "!";
    }
}

class BookTitleStarDecorator extends BookTitleDecorator {
    private $btd;
    public function __construct(BookTitleDecorator $btd_in) {
        $this->btd = $btd_in;
    }
    function starTitle() {
        $this->btd->title = Str_replace(" ","*",$this->btd->title);
    }
}

  writeln('BEGIN TESTING DECORATOR PATTERN');
  writeln('');

  $patternBook = new Book('Gamma, Helm, Johnson, and Vlissides', 'Design Patterns');
 
  $decorator = new BookTitleDecorator($patternBook);
  $starDecorator = new BookTitleStarDecorator($decorator);
  $exclaimDecorator = new BookTitleExclaimDecorator($decorator);
 
  writeln('showing title : ');
  writeln($decorator->showTitle());
  writeln('');
 
  writeln('showing title after two exclaims added : ');
  $exclaimDecorator->exclaimTitle();
  $exclaimDecorator->exclaimTitle();
  writeln($decorator->showTitle());
  writeln('');
 
  writeln('showing title after star added : ');
  $starDecorator->starTitle();
  writeln($decorator->showTitle());
  writeln('');
 
  writeln('showing title after reset: ');
  writeln($decorator->resetTitle());
  writeln($decorator->showTitle());
  writeln('');

  writeln('END TESTING DECORATOR PATTERN');

  function writeln($line_in) {
    echo $line_in."
";
  }
    	
    	

    	
    		
// 1. "lowest common denominator"
interface Widget {
    void draw();
}

// 3. "Core" class with "is a" relationship
class TextField implements Widget {
    private int width, height;

    public TextField(int width, int height) {
        this.width = width;
        this.height = height;
    }
    public void draw() {
        System.out.println("TextField: " + width + ", " + height);
    }
}

// 2. Second level base class with "isa" relationship
abstract class Decorator implements Widget {
    // 4. "has a" relationship
    private Widget widget;

    public Decorator(Widget widget) {
        this.widget = widget;
    }

    // 5. Delegation
    public void draw() {
        widget.draw();
    }
}

// 6. Optional embellishment
class BorderDecorator extends Decorator {
    public BorderDecorator(Widget widget) {
        super(widget);
    }
    public void draw() {
        // 7. Delegate to base class and add extra stuff
        super.draw();
        System.out.println("  BorderDecorator");
    }
}

// 6. Optional embellishment
class ScrollDecorator extends Decorator {
    public ScrollDecorator(Widget widget) {
        super(widget);
    }
    public void draw() {
        super.draw(); // 7. Delegate to base class and add extra stuff
        System.out.println("  ScrollDecorator");
    }
}

public class DecoratorDemo {
    public static void main(String[] args) {
        // 8. Client has the responsibility to compose desired configurations
        Widget widget = new BorderDecorator(new BorderDecorator(new ScrollDecorator(new TextField(80, 24))));
        widget.draw();
    }
}