/**
 * Class to work with locations, and lat/lon pairs.
 * @version 2009-03-31 18:33
 * @url http://code.calum.org/
 * @author calum
 */
public class LocationUtils {


    /**
     * Gets the distance in miles between two javax.microedition.location.Locations
     * Just a wrapper that extracts the lat and lon from the Locations, and calls getDistanceInMiles(oldlat, oldlon, newlat, newlon)
     * @param lastLocation The previous location
     * @param currentLocation The current location
     * @return null if either location is null, or there's a problem
     */
    public static Double getDistanceInMiles(javax.microedition.location.Location lastLocation,
            javax.microedition.location.Location currentLocation) {
        if (lastLocation == null || currentLocation == null) {
            System.err.println("getDistanceInMiles(Location, Location) - one of the Locations is null");
            return null;
        }
        double oldlat = lastLocation.getQualifiedCoordinates().getLatitude();
        double oldlon = lastLocation.getQualifiedCoordinates().getLongitude();
        double newlat = currentLocation.getQualifiedCoordinates().getLatitude();
        double newlon = currentLocation.getQualifiedCoordinates().getLongitude();
        System.out.println("getdistanceInMiles from  " + newlat + ", " + newlon + ", " + oldlat + ", " + oldlon);
        return getDistanceInMiles(oldlat, oldlon, newlat, newlon);
    }


    /**
     * Calculates the distance in miles between two sets of lat, lon coordinates.
     * @param oldlat The old lat
     * @param oldlon The old lon
     * @param newlat The new lat
     * @param newlon The new lon
     * @return The distance in miles from the old lat,lon to the new lat,lon
     */
    public static Double getDistanceInMiles(double oldlat, double oldlon, double newlat, double newlon) {
        System.out.println("getDistanceInMiles(" + oldlat + "," + oldlon + " to " + newlat + "," + newlon + ")");
        //DebugForm_old.getInstance().debug("getdistance " + newlat + ", " + newlon + ", " + oldlat + ", " + oldlon, 1);

//     acos(
//    cos(radians($1)) * cos(radians($2))    *cos(radians($3)) * cos(radians($4)) +
//      cos(radians($1))*sin(radians($2))    *cos(radians($3))*sin(radians($4)) +
//        sin(radians($1))*sin(radians($3))
//  ) * 3963.1

        double dnewlatrads = java.lang.Math.toRadians(newlat);
        double dnewlonrads = java.lang.Math.toRadians(newlon);
        double doldlatrads = java.lang.Math.toRadians(oldlat);
        double doldlonrads = java.lang.Math.toRadians(oldlon);

        double milesd = mMath.acos(
                java.lang.Math.cos(dnewlatrads) * java.lang.Math.cos(dnewlonrads) * java.lang.Math.cos(doldlatrads) * java.lang.Math.cos(doldlonrads) +
                java.lang.Math.cos(dnewlatrads) * java.lang.Math.sin(dnewlonrads) * java.lang.Math.cos(doldlatrads) * java.lang.Math.sin(doldlonrads) +
                java.lang.Math.sin(dnewlatrads) * java.lang.Math.sin(doldlatrads)) * 3963.1f;

        Double miles = new Double(milesd);

        System.out.println("getDistanceInMiles(lat, lon, lat, lon) is returning " + miles + " miles.");
        return miles;
    }

    /**
     * Gets the speed in MPH between two javax.microedition.location.Locations
     * @param lastLocation The previous location (used for elapsed time calculations)
     * @param currentLocation The current location (used for elapsed time calculations)
     * @param distanceMiles the distance travelled in said time
     * @return null if either location is null, or there's a problem
     */
    public static Double getCalcedSpeedMPH(
            javax.microedition.location.Location lastLocation,
            javax.microedition.location.Location currentLocation,
            Double distanceMiles) {
        if (lastLocation == null || currentLocation == null) {
            return null;
        }
        double hours = (currentLocation.getTimestamp() - lastLocation.getTimestamp()) / 3600000D;
        return new Double(distanceMiles.doubleValue() / hours);
    }

    /**
     * This is some of Nicky's wizardry.
     * It calculates the heading from 1 lat/lon to another lat/lon
     */
    public static int getHeading(double oldlat, double oldlon, double newlat, double newlon) {
        System.out.println("Called with " + Double.toString(newlat) + "," + Double.toString(newlon) +
                " : " + Double.toString(oldlat) + "," + Double.toString(oldlon));

        if (newlon == oldlon) {
            if (newlat < oldlat) {
                return 180;
            } else {
                return 0;
            }
        }

        if (newlat == oldlat) {
            if (newlon > oldlon) {
                return 90;
            } else if (newlon < oldlon) {
                return 270;
            }
        }

        if ((newlat > oldlat) && (newlon > oldlon)) {
            double difflat = java.lang.Math.abs(newlat - oldlat);
            double difflon = java.lang.Math.abs(newlon - oldlon);
            double ratio = difflon / difflat;
            double tmp = mMath.atan(ratio);
            return (int) java.lang.Math.toDegrees(tmp);
        } else if ((newlon > oldlon) && (newlat < oldlat)) {
            return 180 - (int) java.lang.Math.toDegrees(mMath.atan(java.lang.Math.abs(newlon - oldlon) / java.lang.Math.abs(newlat - oldlat)));
        } else if ((newlat < oldlat) && (newlon < oldlon)) {
            double difflat = java.lang.Math.abs(newlat - oldlat);
            double difflon = java.lang.Math.abs(newlon - oldlon);
            double ratio = difflon / difflat;
            double tmp = mMath.atan(ratio);
            return 180 + (int) java.lang.Math.toDegrees(tmp);
        } else {
            double difflat = java.lang.Math.abs(newlat - oldlat);
            double difflon = java.lang.Math.abs(newlon - oldlon);
            double ratio = difflon / difflat;
            double tmp = mMath.atan(ratio);
            return 360 - (int) java.lang.Math.toDegrees(tmp);
        }

    }

    /**
     * Returns a friendly heading - e.g. SouthWest
     * @param degrees The heading to convert
     */
    public static String getFriendlyHeadingString(int degrees) {
        if (degrees == -999) {
            return "?";
        }
        if (degrees >= 337 || degrees < 22) {
            return "N";
        }
        if (degrees >= 22 && degrees < 67) {
            return "NE";
        }
        if (degrees >= 67 && degrees < 112) {
            return "E";
        }
        if (degrees >= 112 && degrees < 157) {
            return "SE";
        }
        if (degrees >= 157 && degrees < 202) {
            return "S";
        }
        if (degrees >= 202 && degrees < 247) {
            return "SW";
        }
        if (degrees >= 247 && degrees < 292) {
            return "W";
        }
        if (degrees >= 292 && degrees < 337) {
            return "NW";
        }
        return "?" + degrees;
    }

    public static double calumround(double arg, int places) {
        //System.out.println("calumround("+ Double.toString(arg) +"," + Integer.toString(places)+ ")");
        double tmp = (double) arg * (pow(10, places));
        int tmp1 = (int) Math.floor(tmp + 0.5);
        double tmp2 = (double) tmp1 / (pow(10, places));
        return tmp2;
    }

    public static int pow(int arg, int times) {
        int ret = 1;
        for (int i = 1; i <= times; i++) {
            ret = ret * arg;
        }
        return ret;
    }


}