import swisseph.*;

/**
* This class calculates some nakshatra starting and ending dates
* for february 1986 in India (time zone offset 5.5 hours).
*
* It calculates topocentric (for Bangalore) and geocentric dates,
* even though geocentric seems to be normally used in India.
*/
public class NakshatraDates {

	final static double TZ_OFFSET_HOURS = 5.5;	// IST

	final static String[] nakshatraNames = new String[] {
		"Ashvini",
		"Bharani",
		"Krittika",
		"Rohini",
		"Mrigashirsha",
		"Ardra",
		"Punarvasu",
		"Pushya",
		"Ashlesha",
		"Magha",
		"Purva Phalguni",
		"Uttar Phalguni",
		"Hasta",
		"Chitra",
		"Svati",
		"Vishakha",
		"Anuradha",
		"Jyeshtha",
		"Mula",
		"Purvashadha",
		"Uttarashadha",
		"Shravan",
		"Shravishtha",
		"Shatabhisha",
		"Purva Bhadrapada",
		"Uttara Bhadrapada",
		"Revati",
	};
/*
	final static String[] nakshatraNames = new String[] {
		"अश्विनि",
		"भरणी",
		"क्रृत्तिका",
		"रोहिणी",
		"म्रृगशीर्षा",
		"आर्द्रा",
		"पुनर्वसु",
		"पुष्य",
		"आश्लेषा",
		"मघा",
		"पूर्व फाल्गुनी",
		"उत्तर फाल्गुनी",
		"हस्त",
		"चित्रा",
		"स्वाति",
		"विशाखा",
		"अनुराधा",
		"ज्येष्ठा",
		"मूल",
		"पूर्वाषाढ़ा",
		"उत्तराषाढ़ा",
		"श्रावण",
		"श्रविष्ठा",
		"शतभिषा",
		"पूर्व भाद्रपदा",
		"उत्तर भाद्रपदा",
		"रेवती",
	};
*/

	SwissEph sw = new SwissEph("./ephe");

	public static void main(String[] p) {
		NakshatraDates sj = new NakshatraDates();
		SweDate sd = new SweDate();

		sd.setDate(1986, 1, 1, -TZ_OFFSET_HOURS);

		System.out.println("Some nakshatras for Bangalore (77.5667E 12.9667N) starting with Ashvini in January 1986.");
		for(int naksh = 0; naksh < 27; naksh++) {	// Nakshatra number zero based
			double nakshStart = sj.getNextNakshatraStart(sd.getJulDay(), naksh, true);
			double nakshEnd = sj.getNextNakshatraEnd(sd.getJulDay(), naksh, true);
			System.out.println(String.format("topocentric %-20s: %s - %s",
					nakshatraNames[naksh],
					sj.toDateString(nakshStart, TZ_OFFSET_HOURS),
					sj.toDateString(nakshEnd, TZ_OFFSET_HOURS)));

			// Same with geocentric positions:
			nakshStart = sj.getNextNakshatraStart(sd.getJulDay(), naksh, false);
			nakshEnd = sj.getNextNakshatraEnd(sd.getJulDay(), naksh, false);
			System.out.println(String.format(" geocentric %-20s: %s - %s\n",
					nakshatraNames[naksh],
					sj.toDateString(nakshStart, TZ_OFFSET_HOURS),
					sj.toDateString(nakshEnd, TZ_OFFSET_HOURS)));
		}
	}

	double getNextNakshatraStart(double juld, int nakshatra, boolean topoctr) {
		double geopos[] = new double[] {77.5667, 12.9667, 0};

		sw.swe_set_sid_mode(SweConst.SE_SIDM_LAHIRI, 0, 0);
		sw.swe_set_topo(geopos[0], geopos[1], 0);
		int flags = SweConst.SEFLG_SWIEPH |
				SweConst.SEFLG_TRANSIT_LONGITUDE |
				SweConst.SEFLG_SIDEREAL;
		if (topoctr) {
			flags |= SweConst.SEFLG_TOPOCTR;
		}

		TransitCalculator tc = new TCPlanet(
				sw,
				SweConst.SE_MOON,
				flags,
				nakshatra * (360. / 27.));

		return sw.getTransitUT(tc, juld, false);
	}
	double getNextNakshatraEnd(double juld, int nakshatra, boolean topoctr) {
		return getNextNakshatraStart(juld, (nakshatra + 1) % 27, topoctr);
	}

	String toDateString(double d, double tzHours) {
		SweDate sd = new SweDate(d + tzHours / 24. + 0.5/24./3600. /* round to second */);
		double hour = sd.getHour();
		return String.format(java.util.Locale.US, "%4d/%02d/%02d, %2d:%02d:%02dh",
			sd.getYear(),
			sd.getMonth(),
			sd.getDay(),
			(int)hour,
			(int)((hour-(int)hour)*60),
			(int)((hour*60-(int)(hour*60))*60));
	}
}