import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)

public class Zombie extends Actor
{
    private GreenfootImage zombieleft;
    private GreenfootImage zombieright;
    
    public Zombie()
    {
        System.out.println("Zombie created.");
        zombieleft = new GreenfootImage("image_zombie_left.png");
        zombieright = new GreenfootImage("image_zombie_right.png");
    }
    
    public void act() 
    {
        if (getOneIntersectingObject(Building.class) == null)
        {
            chasePlayer();
        }
        else
        {
            pathing();
        }
    }
    
    public void chasePlayer()
    {
        Player player = (Player)getWorld().getObjects(Player.class).get(0);
        
        int pX = player.getX();
        int pY = player.getY();
        
        int dx = 1;
        int dy = 1;
        
        if (getX() > pX)
        {
            dx = -1;
            setImage(zombieleft);
        }
        else
        {
            setImage(zombieright);
        }
        
        if (getY() > pY)
        {
            dy = -1;
        }

        setLocation(getX() + dx, getY() + dy);
    }
    
    public void pathing()
    {
        Player player = (Player)getWorld().getObjects(Player.class).get(0);
        Building building = (Building)getWorld().getObjects(Building.class).get(0);
        
        
        int pX = player.getX();
        int pY = player.getY();
        
        int bX = building.getX();
        int bY = building.getY();
        
        int deltaX = player.getX() - getX();
        int deltaY = player.getY() - getY();
        
        // if player is to the right or left of the zombie, the zombie will only move up or down to clear the building
        if ((getX() + 1 == bX) || (getX() - 1 == bX))
            {
                if (deltaY < 0)
                {
                    setLocation(getX(), getY() - 1);
                }
                else
                {
                    setLocation(getX(), getY() + 1);
                }
            }
        
        // if player is above or below the zombie, the zombie will only move left or right to clear the building
        if ((getY() + 1 == bY) || (getY() + 1 == bY))
           {
               if (deltaX < 0)
                {
                    setLocation(getX() + 1, getY());
                }
                else
                {
                    setLocation(getX() - 1, getY());
                }
           }
    }
}