import java.util.HashMap;

/**
 * Ball Class
 * - Tracking ball as well as basic example of Voronoi Diagram
 *  to work out goal shots and passing. Provides hashmap to hold all the
 *  ball position data and also has methods to work out distance for
 *  goals and passing
 * @author Akbar Sherwani
 * @date 27th November
 * @version 0.1
 */

public class Ball {

	public double posx; // Position x
	public double posy; // Position y
	public double velx; // Velocity x
	public double vely; // Velocity y
	private HashMap<Integer, Position> touches; // Touches Hashmap for ball pos

	/**
	 * Constructor
	 * Intialises ball class
	 */

	public Ball()
	{
		// Initialise 
		posx = 0.0;
		posy = 0.0;
		velx = 0.0;
		vely = 0.0;

		touches = new HashMap<Integer , Position>();
	}

	/**
	 * Set
	 * Sets ball position and velocity
	 * @param posx sets postion x
	 * @param posy sets postion y
	 * @param velx sets velocity x
	 * @param vely sets velocity y
	 */
	public void set(double posx, double posy, double velx, double vely)
	{
		this.posx = posx;
		this.posy = posy;
		this.velx = velx;
		this.vely = vely;
	}

	/**
	 * Ball kicked 
	 * Sets ball position and velocity into a position class
	 * which is then added to the touches hashmap
	 * @param player player number
	 */
	public void BallKicked(int player)
	{
		//get ball position and add to hashmap
		Position pos = new Position(posx, posy);
		touches.put(player, pos);
	}

	/**
	 * Ball passed 
	 * Find pass distance
	 * @param playera player who passed
	 * @param playerb player who recieved ball
	 * @return goal distance string
	 */
	public int BallPass(int playera, int playerb)
	{
		Position posa = (Position) touches.get(playera);
		Position posb = (Position) touches.get(playerb);

		//Get Distance between two positions
		double passl = Distance(posa, posb);
		int dis = (int) passl;
		return dis;
	}

	/**
	 * Ball shot 
	 * Find shot distance
	 * @param playera player who shot
	 * @param playerb goalkeeper who saved
	 * @return goal distance string
	 */
	public int BallShot(int playera, int playerb)
	{
		Position posa = (Position) touches.get(playera);
		Position posb = (Position) touches.get(playerb);

		//Get Distance between two positions
		double passl = Distance(posa, posb);
		int dis = (int) passl;
		return dis;
	}

	/**
	 * Goal shot 
	 * Find shot distance to center of goal
	 * @param playera player who shot
	 * @return goal distance string
	 */
	public int BallGoal(int playera)
	{
		Position posa = (Position) touches.get(playera);
		Position posb;
		// Depends on which goal posts are you aiming for below
		// Or remove all negatives
		if(playera > 11)
		{
			posb = new Position(-53,0);
		}
		else
		{
			posb = new Position(53,0);
		}

		//Get Distance between two positions
		double passl = Distance(posa, posb);
		int dis = (int) passl;
		return dis;
	}

	/**
	 * Goal Player Position 
	 * Find shot distance to center of goal
	 * @param playera player who shot
	 * @return goal distance string
	 */
	public Position BallGoalPlayer(int playera)
	{
		Position posa = (Position) touches.get(playera);
		return posa;
	}

	/**
	 * Ball Distance
	 * Find pass distance
	 * @param a position of each
	 * @param b position of each
	 * @return distance between the two points
	 */

	public double Distance(Position a, Position b)
	{
		if(a != null || b != null)
		{
			double diffx = Math.abs(a.getPosx() - b.getPosx());
			double diffy = Math.abs(a.getPosy() - b.getPosy());
			//System.out.println(pythag(diffx, diffy));
			return pythag(diffx, diffy);
		}
		else
		{
			return 0;
		}
	}

	/**
	 * Pythag
	 * Find pass distance
	 * @param a position of each
	 * @param b position of each
	 * @return pythag value of the two points
	 */

	public double pythag(double a, double b)
	{
		double absa,absb;
		absa=Math.abs(a);
		absb=Math.abs(b);
		if(absa > absb)
			return absa*Math.sqrt(1.+Math.pow((absb/absa),2));
		else
			if(absb==0.)
				return 0.;
			else
				return absb*Math.sqrt(1.+Math.pow((absa/absb),2));
	}

	/** 
	 * Get method for posx
	 * @return position x of the ball
	 */
	public double getPosx() {
		return posx;
	}

	/** 
	 * Get method for posy
	 * @return position y of the ball
	 */
	public double getPosy() {
		return posy;
	}

	/** 
	 * Get final ball position
	 * @return position x of the ball
	 */
	public Position getBallPos() {
		Position pos = new Position(posx, posy);
		return pos;
	}




}