Sun.java

/**
 *  C-Nery - A home automation web application for C-Bus.
 *  Copyright (C) 2008,2009,2012  Dave Oxley <dave@daveoxley.co.uk>.
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as
 *  published by the Free Software Foundation, either version 3 of the
 *  License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package com.daveoxley.cnery.util;

import java.io.Serializable;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;
import org.jboss.seam.annotations.In;
import org.jboss.seam.annotations.Name;
import uk.me.jstott.coordconv.LatitudeLongitude;
import uk.me.jstott.sun.Time;
import uk.me.jstott.util.JulianDateConverter;

/**
 *
 * @author Dave Oxley <dave@daveoxley.co.uk>
 */
@Name("sun")
public class Sun implements Serializable {

    @In
    private LatitudeLongitude position;

    public String getNextSunriseDisplay() {
        SimpleDateFormat formatter = new SimpleDateFormat("HH:mm:ss");

        try {
            GregorianCalendar currentTime = new GregorianCalendar();
            GregorianCalendar sunriseTime = nextSunrise(currentTime);

            String sunriseString = "Today at ";
            if (sunriseTime.get(Calendar.DAY_OF_YEAR) > currentTime.get(Calendar.DAY_OF_YEAR))
                sunriseString = "Tomorrow at ";
            sunriseString += formatter.format(sunriseTime.getTime());

            return sunriseString;
        } catch (Exception ex) {
            return "error";
        }
    }

    public String getNextSunsetDisplay() {
        SimpleDateFormat formatter = new SimpleDateFormat("HH:mm:ss");

        try {
            GregorianCalendar currentTime = new GregorianCalendar();
            GregorianCalendar sunsetTime = nextSunset(currentTime);

            String sunsetString = "Today at ";
            if (sunsetTime.get(Calendar.DAY_OF_YEAR) > currentTime.get(Calendar.DAY_OF_YEAR))
                sunsetString = "Tomorrow at ";
            sunsetString += formatter.format(sunsetTime.getTime());

            return sunsetString;
        } catch (Exception ex) {
            return "error";
        }
    }

    public GregorianCalendar nextSunrise(GregorianCalendar currentTime) {

        currentTime = (GregorianCalendar)currentTime.clone();

        TimeZone currentTimezone = currentTime.getTimeZone();
        boolean dst = currentTimezone.inDaylightTime(currentTime.getTime());
        double currentJulian = JulianDateConverter.dateToJulian(currentTime);

        Time time = uk.me.jstott.sun.Sun.sunriseTime(currentJulian, position, currentTimezone, dst);
        GregorianCalendar sunriseTime = getGregorianCalendar(currentTime, time);

        if (!currentTime.after(sunriseTime))
            return sunriseTime;

        currentTime.add(Calendar.DAY_OF_YEAR, 1);
        currentJulian = JulianDateConverter.dateToJulian(currentTime);

        time = uk.me.jstott.sun.Sun.sunriseTime(currentJulian, position, currentTimezone, dst);

        return getGregorianCalendar(currentTime, time);
    }

    public GregorianCalendar previousSunrise(GregorianCalendar currentTime) {

        currentTime = (GregorianCalendar)currentTime.clone();

        TimeZone currentTimezone = currentTime.getTimeZone();
        boolean dst = currentTimezone.inDaylightTime(currentTime.getTime());
        double currentJulian = JulianDateConverter.dateToJulian(currentTime);

        Time time = uk.me.jstott.sun.Sun.sunriseTime(currentJulian, position, currentTimezone, dst);
        GregorianCalendar sunriseTime = getGregorianCalendar(currentTime, time);

        if (currentTime.after(sunriseTime))
            return sunriseTime;

        currentTime.add(Calendar.DAY_OF_YEAR, -1);
        currentJulian = JulianDateConverter.dateToJulian(currentTime);

        time = uk.me.jstott.sun.Sun.sunriseTime(currentJulian, position, currentTimezone, dst);

        return getGregorianCalendar(currentTime, time);
    }

    public GregorianCalendar nextSunset(GregorianCalendar currentTime) {

        currentTime = (GregorianCalendar)currentTime.clone();

        TimeZone currentTimezone = currentTime.getTimeZone();
        boolean dst = currentTimezone.inDaylightTime(currentTime.getTime());
        double currentJulian = JulianDateConverter.dateToJulian(currentTime);

        Time time = uk.me.jstott.sun.Sun.sunsetTime(currentJulian, position, currentTimezone, dst);
        GregorianCalendar sunsetTime = getGregorianCalendar(currentTime, time);

        if (!currentTime.after(sunsetTime))
            return sunsetTime;

        currentTime.add(Calendar.DAY_OF_YEAR, 1);
        currentJulian = JulianDateConverter.dateToJulian(currentTime);

        time = uk.me.jstott.sun.Sun.sunsetTime(currentJulian, position, currentTimezone, dst);

        return getGregorianCalendar(currentTime, time);
    }

    public GregorianCalendar previousSunset(GregorianCalendar currentTime) {

        currentTime = (GregorianCalendar)currentTime.clone();

        TimeZone currentTimezone = currentTime.getTimeZone();
        boolean dst = currentTimezone.inDaylightTime(currentTime.getTime());
        double currentJulian = JulianDateConverter.dateToJulian(currentTime);

        Time time = uk.me.jstott.sun.Sun.sunsetTime(currentJulian, position, currentTimezone, dst);
        GregorianCalendar sunsetTime = getGregorianCalendar(currentTime, time);

        if (currentTime.after(sunsetTime))
            return sunsetTime;

        currentTime.add(Calendar.DAY_OF_YEAR, -1);
        currentJulian = JulianDateConverter.dateToJulian(currentTime);

        time = uk.me.jstott.sun.Sun.sunsetTime(currentJulian, position, currentTimezone, dst);

        return getGregorianCalendar(currentTime, time);
    }

    private GregorianCalendar getGregorianCalendar(GregorianCalendar gc, Time time) {

        gc = (GregorianCalendar)gc.clone();

        gc.set(Calendar.HOUR_OF_DAY, time.getHours());
        gc.set(Calendar.MINUTE, time.getMinutes());

        int seconds = (int)Math.floor(time.getSeconds());
        int ms = (int)Math.round(time.getSeconds() - seconds) * 1000;
        gc.set(Calendar.SECOND, seconds);
        // Set ms to 0 and add in case the rounding set ms to 1000ms
        gc.set(Calendar.MILLISECOND, 0);
        gc.add(Calendar.MILLISECOND, ms);

        return gc;
    }
}