Astro.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */
package org.openhab.action.astro.internal;

import java.util.Calendar;
import java.util.Date;

import org.openhab.binding.astro.internal.calc.SunCalc;
import org.openhab.binding.astro.internal.model.Sun;
import org.openhab.core.scriptengine.action.ActionDoc;
import org.openhab.core.scriptengine.action.ParamDoc;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This class provides static methods that can be used in automation rules for
 * calculating astronomical data.
 *
 * @author Gerhard Riegler
 * @since 1.7.0
 */
public class Astro {
    private static final Logger logger = LoggerFactory.getLogger(Astro.class);

    private static final SunCalc sunCalc = new SunCalc();
    // simple microcache
    private static AstroConfig lastConfig;
    private static Sun lastSun;

    @ActionDoc(text = "Returns the sunrise start for the given date and coordinates")
    public static Calendar getAstroSunriseStart(
            @ParamDoc(name = "date", text = "The date to calculate the sunrise") Date date,
            @ParamDoc(name = "latitude", text = "The latitude") double latitude,
            @ParamDoc(name = "longitude", text = "The longitude") double longitude) {
        return getSun(date, latitude, longitude).getRise().getStart();
    }

    @ActionDoc(text = "Returns the sunrise end for the given date and coordinates")
    public static Calendar getAstroSunriseEnd(
            @ParamDoc(name = "date", text = "The date to calculate the sunrise") Date date,
            @ParamDoc(name = "latitude", text = "The latitude") double latitude,
            @ParamDoc(name = "longitude", text = "The longitude") double longitude) {
        return getSun(date, latitude, longitude).getRise().getEnd();
    }

    @ActionDoc(text = "Returns the sunset start for the given date and coordinates")
    public static Calendar getAstroSunsetStart(
            @ParamDoc(name = "date", text = "The date to calculate the sunset") Date date,
            @ParamDoc(name = "latitude", text = "The latitude") double latitude,
            @ParamDoc(name = "longitude", text = "The longitude") double longitude) {
        return getSun(date, latitude, longitude).getSet().getStart();
    }

    @ActionDoc(text = "Returns the sunset end for the given date and coordinates")
    public static Calendar getAstroSunsetEnd(
            @ParamDoc(name = "date", text = "The date to calculate the sunset") Date date,
            @ParamDoc(name = "latitude", text = "The latitude") double latitude,
            @ParamDoc(name = "longitude", text = "The longitude") double longitude) {
        return getSun(date, latitude, longitude).getSet().getEnd();
    }

    /**
     * Calculates the sun data.
     */
    private static Sun getSun(Date date, double latitude, double longitude) {
        if (date == null) {
            logger.warn("Unknown date: {}, using current date", date);
            date = new Date();
        }
        AstroConfig config = new AstroConfig(date, latitude, longitude);
        if (lastConfig == null || !lastConfig.equals(config)) {
            Calendar cal = Calendar.getInstance();
            cal.setTime(date);
            lastSun = sunCalc.getSunInfo(cal, latitude, longitude);
            lastConfig = config;
        }
        return lastSun;
    }
}