/**
 * AbstractVehicle.java
 *
 * @author Zuo Yan
 * @version 1.0
 */

package vehicle;

import java.awt.Graphics2D;

import world.World;

/**
 * An AbstractVehicle has the current World and a MovementTracker.<p>
 * 
 * Any subclass must implement the createShapes(), update(), and draw() methods.<p>
 * The createShapes() method is called from this constructor. It should instantiate
 * all necessary geometrical shapes associated with this vehicle and register it with the
 * MovementTracker of this object.<br>
 * The draw() method is called whenever it's time to paint/repaint the screen. This can happen at any time.
 * State changes should not occur in this method. Presumably, this method should just set the color of the different
 * shapes created in createShapes() and call the necessary methods in the graphics module.<br>
 * The update() method is called by the world whenever it's time to update the state of the world.
 * This occurs onces World.FPS times per second. Any changes to the state of this vehicle such as moving
 * should occur in this method.
 */
public abstract class AbstractVehicle {
    protected World theWorld; // The world we are in
    protected MovementTracker mvTrack; // Movement tracker

    /**
     * Initialize variables for the vehicle.
     * 
     * @param world the World this vehicle is in
     */
    public AbstractVehicle(World ourWorld) {
        this.theWorld = ourWorld;
        
        mvTrack = new MovementTracker();
        
        //Some advice: in each subclass, write a createShapes method
        //call it in the subclass constructor:
        //createShapes();
        //such a method would create all the shapes needed by the vehicle.
    }

    /**
     * Returns the current x position of the center point
     * of all the shapes contained in this tracker.
     * 
     * @return x-coordinate of the shapes' center
     */
    public double getX(){
        return mvTrack.getX();
    }
    
    /**
     * Returns the current y position of the center point
     * of all the shapes contained in this tracker.
     * 
     * @return y-coordinate of the shapes' center
     */
    public double getY(){
        return mvTrack.getY();
    }
    
    /**
     * Gets the orientation changed from the inital drawing
     * 
     * @return the angle in radians
     */
    public double getOrientation() {
        return mvTrack.getOrientation();
    }
    
    /**
     * Set the current orientation with postive sign meaning clockwise.
     * 
     * @param theta the angle in radians
     */
    public void setOrientation(double theta) {
        mvTrack.setRotation(theta);
    }
    
    /**
     * Rotate shapes by theta with postive sign meaning clockwise
     * 
     * @param theta the angle in radians
     */
    public void rotateBy(double theta) {
        mvTrack.rotateBy(theta);
    }
    
    /**
     * Move to (x, y) in the world.
     * 
     * @param x the x-coordinate to move to
     * @param y the y-coordinate to move to
     */
    public void moveTo(double x, double y) {
        mvTrack.moveTo(x, y);
    }
    
    /**
     * Move by xoffset and yoffset pixels.
     * 
     * @param xoffset the number of pixels to move in the x-axis direction
     * @param yoffset the number of pixelse to move in the y-axis direction
     */
    public void moveBy(double xoffset, double yoffset) {
        mvTrack.moveBy(xoffset, yoffset);
    }
    
    /**
     * Retrieves the MovementTracker.
     * 
     * @return the MovementTracker associated with this vehicle
     */
    public MovementTracker getTracker(){
        return mvTrack;
    }
    
    /**
     * Handles a collision with another vehicle.
     * The default is to do nothing.
     * Note:  The method is not required.
     * 
     * @param av the other vehicle
     */
    public void handleCollision(AbstractVehicle av) {
        //System.out.println("Collision occured at around: (" + getX() + ", " + getY() + ")");
    }
    
    /**
     * Called by World when it's time to update.
     * Any state changes to this vehicle should occur here.
     */
    public abstract void update();

    /**
     * Use the graphics system to actually paint the shapes
     * we have created.
     * 
     * @param g the graphics system to use
     */
    public abstract void draw(Graphics2D g);
}