/**
 * {@link <a href=
 * "https://[Log in to view URL]"
 * target= "_blank"></a>}
 * 
 * @author itammb ( Italia Massimiliano Buscati )
 * @version JDK 1.15
 *
 */
class Main {

	interface Command {
	    public void executeDraw();
	    public void executeErase();
	}
	
	public static class ShapeConcreteCommand implements Command {
		final Receiver logic; // business logic
		final String shape;   // parametro metodo
	    
	    public ShapeConcreteCommand(Receiver logic, String shape) {
	        this.logic = logic;
	        this.shape = shape;
	    }
	    
	    public void executeDraw() {
	    	logic.draw(shape); // trasforma una chiamata a una logica, come un oggetto autonomo
	    }
	    
	    public void executeErase() {
	    	logic.erase(shape);
	    }
	}
	
	public static class Receiver {
		
	    // business logic
	    
	    public void draw(String shape) {
	        System.out.println("Drawing " + shape);
	    }
	    
	    public void erase(String shape) {
	        System.out.println("Erasing " + shape);
	    }
	}
	
	public static class Invoker {  
	    Command command;
	    
	    public void setCommand(Command command) {
	        this.command = command;
	    }
	    
	    // avvia la richiesta del client
	    
	    public void draw() {
	        command.executeDraw();
	    }
	    
	    public void erase() {
	       command.executeErase();
	    }
	}
	

	public static void main(String args[]) {
		// Unit test - uso del design pattern: Command
		
		// invocker: avvia una richieta [Command]
		Invoker sketchBoard = new Invoker();  
		    
		// receiver: business logic
		Receiver drawShape = new Receiver();  
		    
		// Command: esegue una richiesta [receiver, parametri]
		ShapeConcreteCommand commad = new ShapeConcreteCommand(drawShape, "circle");   
		
		sketchBoard.setCommand(commad);   
		sketchBoard.draw();           
		sketchBoard.erase();
	}
}