package org.stwing.jrank.bug.gpsemulator.impl;

import org.osgi.framework.BundleContext;
import org.stwing.jrank.bug.gpsemulator.GpsEmulator;

import com.buglabs.bug.module.gps.pub.LatLon;
import com.buglabs.util.StringUtil;

/**
 * 

 * Plots a straight path from an initial point along a specific angle and with a
 * specific velocity.
 * 
 * 

 * Properties (see also {@link GpsEmulator}}:
 * 

 * 
org.stwing.jrank.bug.gpsemulator.angle - The angle or travel
 * from the initial point in degrees. Defaults to 0.
 * 
 * 

 * 
 * @author Jacob Rank
 * 
 */
public class StraightLinePath extends GpsEmulator {

	private static final String KEY_ANGLE = "org.stwing.jrank.bug.gpsemulator.angle";

	// Default property values
	private double angle = 0.0;		// degrees
	
	public void initialize(BundleContext context) {
		super.initialize(context);
		
		String value;
		
		value = context.getProperty(KEY_ANGLE);
		if (value != null) {
			angle = Double.parseDouble(value);
		}
	}

	public LatLon getLatitudeLongitude() {
		LatLon latLon = new LatLon();
		
		// Determine distance
		double elapsedTime = getNextTime();
		double distance = elapsedTime / 1000.0 * velocity;
		
		// Determine theta
		double theta = converter.degreeToRadian(angle);
		
		// Convert distance and theta to UTM offsets
		double utmNorthingDelta = distance * Math.sin(theta);
		double utmEastingDelta = distance * Math.cos(theta);
		
		// Get current position in UTM
		String[] utmPosition = StringUtil.split(converter.latLon2UTM(initialLatitude, initialLongitude), " ");
		double utmNorthing = Long.parseLong(utmPosition[2]);
		double utmEasting = Long.parseLong(utmPosition[3]);
		
		// Update UTM position and convert back to lat/lon
		utmNorthing += utmNorthingDelta;
		utmEasting += utmEastingDelta;
		double[] newLatLon = converter.utm2LatLon(utmPosition[0] + " " + utmPosition[1] + " " + utmNorthing + " " + utmEasting);
		
		latLon.latitude = newLatLon[0];
		latLon.longitude = newLatLon[1];
		
		return latLon;
	}
}