package LandThePlane;

import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
import java.util.List;
import java.util.ArrayList;

/**
 * An AntiAirGuns main goal is to kill the plane.
 * It tries to do this by following the planes and if the gun is loaded shoots a bullet.
 * The loadtime is defined in the shootInterval variable.
 * Guns get inactive when a message is displayed, this means either the player landed or died.
 * 
 * @author Kevin van Oosterhout
 * @version 1.0
 */
public class AntiAirGun extends Actor
{
    private List<Plane> planes = new ArrayList();
    private int counter = 0;
    private int shootInterval;
    private boolean active = true;
    
    /**
     * initiate the gun.
     */
    public AntiAirGun(int shootInterval) {
        this.shootInterval = shootInterval;
        setImage("AntiAirGun.png");
    }
    /**
     * Use the method findPlane to follow the plane and kill it.
     */
    public void act() 
    {
        if(active == true) {
            findPlane();
        }
    }    
    
    /**
     * First we read all planes in a List called planes. We follow one, this is not random,
     * but we don't really care which one we follow, in our game, we'll mostly have just one plane,
     * and if we have more, we're comfortable with the gun just following the last one in the List.
     * Last, we call the shoot method.
     */
    private void findPlane() {
        planes = getWorld().getObjects(Plane.class);
        for (int i=0; i < planes.size(); i++) {
            Plane plane = planes.get(i);
            int px = plane.getX();
            int py = plane.getY();
            turnTowards(px,py);
            shoot(px,py);
        }
    }
    
    /**
     * We need to shoot the plane in order to kill it. 
     * First we check wether the Gun is loaded, this is the case when the counter is 
     * equal to or higher than the shootInterval.
     * If so, we create a new Bullet and give it the correct rotation/heading, 
     * and place it in the world where the position of this object is. We set the counter to 0.
     * 
     * If not, we add up 1 to our counter.
     */
    private void shoot(int x, int y) {
        if (counter >= shootInterval) {
            getWorld().addObject(new Bullet(getRotation()),getX(), getY());
            counter = 0;
        } else {
            counter++;
        }
    }
    
    /**
     * When a message is displayed, it will set the gun to inactive, we do this here.
     */
    public void setInactive() {
        active = false;
    }
}