package seng302.Model;

import org.geotools.referencing.GeodeticCalculator;
import seng302.Constants;
import seng302.Controllers.RaceController;
import seng302.GPSCoordinate;

import java.awt.geom.Point2D;
import java.util.ArrayList;

/**
 * Created by cbt24 on 6/03/17.
 */
public class ConstantVelocityRace extends Race {

    /**
     * Initialiser for a constant velocity race
     *
     * @param startingBoats in race
     * @param legs in race
     * @param controller of race
     * @param scaleFactor of race
     */
    public ConstantVelocityRace(BoatInRace[] startingBoats, ArrayList<Leg> legs, RaceController controller, int scaleFactor) {
        super(startingBoats, legs, controller, scaleFactor);
    }


    /**
     * Calculates the distance a boat has travelled and updates its current position according to this value.
     *
     * @param boat to be updated
     * @param millisecondsElapsed since last update
     */
    protected void updatePosition(BoatInRace boat, int millisecondsElapsed) {

        //distanceTravelled = velocity (nm p hr) * time taken to update loop
        double distanceTravelled = (boat.getScaledVelocity() * millisecondsElapsed) / 3600000;

        double totalDistanceTravelled = distanceTravelled + boat.getDistanceTravelledInLeg();

        boolean finish = boat.getCurrentLeg().getName().equals("Finish");
        if (!finish) {
            //update boat's distance travelled
            boat.setDistanceTravelledInLeg(totalDistanceTravelled);
            //Calculate boat's new position by adding the distance travelled onto the start point of the leg
            boat.setCurrentPosition(calculatePosition(boat.getCurrentLeg().getStartMarker().getAverageGPSCoordinate(),
                    totalDistanceTravelled, boat.calculateAzimuth()));
        }
    }

    /**
     * Calculates the boats next GPS position based on its distance travelled and heading
     *
     * @param oldCoordinates    GPS coordinates of the boat's starting position
     * @param distanceTravelled distance in nautical miles
     * @param azimuth           boat's current direction. Value between -180 and 180
     * @return The boat's new coordinate
     */
    public static GPSCoordinate calculatePosition(GPSCoordinate oldCoordinates, double distanceTravelled, double azimuth) {

        //Find new coordinate using current heading and distance

        GeodeticCalculator geodeticCalculator = new GeodeticCalculator();
        //Load start point into calculator
        Point2D startPoint = new Point2D.Double(oldCoordinates.getLongitude(), oldCoordinates.getLatitude());
        geodeticCalculator.setStartingGeographicPoint(startPoint);
        //load direction and distance tranvelled into calculator
        geodeticCalculator.setDirection(azimuth, distanceTravelled * Constants.NMToMetersConversion);
        //get new point
        Point2D endPoint = geodeticCalculator.getDestinationGeographicPoint();

        return new GPSCoordinate(endPoint.getY(), endPoint.getX());
    }

}