import greenfoot.*;

/**
 *  A user-controlled spaceship that can be teleported from one portal to another
 *  This class uses a somewhat make-shift move algorithm with drift slowing to stop
 *  (although, in space, this kind of slowing is not present)
 */
public class Ship extends Actor
{
    int speed = 5;
    /**
     * Method act: move spaceship and check teleporting status
     */
    public void act() 
    {
        move();
    }

    /**
     * Method move: checks for keystrokes and applies the changes, then moves the ship.
     * I applied a bit of slowing to the ship's speed (so it would be drifting to a stop)
     */
    private void move()
    {
        int dz = 0;
        if (Greenfoot.isKeyDown("d")) dz++;
        if (Greenfoot.isKeyDown("a")) dz--;
        setRotation(getRotation() + dz * 5);
        int ds = -1;
        if (Greenfoot.isKeyDown("w")) ds += 2;
        speed += ds;
        if (speed < 0) speed = 0;
        if (speed > 90) speed = 90;
        if (speed >= 200) move(speed / 100);
        if (Greenfoot.isKeyDown("s")) ds += 5;
        speed += ds;
        if (speed < 5) speed = 5;
        if (speed > 200) speed = 200;
        if (speed >= 20) move(speed / 10);
    }
}