/**
 * AstroFormat<p>
 *
 * Various static methods.
 *
 * Algorithm 46 and 47 from "Practical Astronomy with Your Calculator"
 * (3rd Edition), by Patrick Duffett-Smith ISBN 0-521-35699-7
 *
 * Copyright &copy; 1996-1998 Martin Minow. All Rights Reserved.<p>
 *
 * Permission to use, copy, modify, and redistribute this software and its
 * documentation for personal, non-commercial use is hereby granted provided that
 * this copyright notice and appropriate documentation appears in all copies. This
 * software may not be distributed for fee or as part of commercial, "shareware,"
 * and/or not-for-profit endevors including, but not limited to, CD-ROM collections,
 * online databases, and subscription services without specific license.<p>
 *
 * @author <a href="mailto:minow@merrymeet.com">Martin Minow</a>
 * @version 1.0
 * Set tabs every 4 characters.
 */
// package Classes;

import java.util.*;
import java.text.*;

public class AstroFormat implements Constants
{
    public static final boolean CIVIL_FORMAT		= true;
    public static final boolean ASTRO_FORMAT		= false;
	/*
	 * We want to display the degree sign, but this presumes
	 * that the compiler and Applet Runner properly -- and
	 * consistently -- converts the Macintosh degree character
	 * to/from Unicode. For now, we'll use 'd', 'm' and 's'
	 */
	private static final char degreeSign			= '\u00B0'; // 'd';
	private static final char minuteSign			= '\'';		// 'm';
	private static final char secondSign			= '"';		// 's';

	/**
	 * Return the date string for the system TimeZone
	 */
	public static String getLocalDateString(
			Date			instant
		)
	{
		DateFormat			dateFormat	= DateFormat.getDateTimeInstance();
		return (dateFormat.format(instant));
	}
	/**
	 * Return the date string for a user-specified TimeZone.
	 */
	public static String getLocalDateString(
			Date			instant,
			TimeZone		timeZone
		)
	{
		DateFormat			dateFormat = DateFormat.getDateTimeInstance();
		dateFormat.setTimeZone(timeZone);
		return (dateFormat.format(instant));
	}
	public static String getGMTDateString(
			Date			instant
		)
	{
		try {
			SimpleTimeZone		tzGMT		= (SimpleTimeZone) TimeZone.getTimeZone("GMT");
			SimpleDateFormat	dateFormat 	= new SimpleDateFormat("yyyy.MM.dd HH:mm zz");
			dateFormat.setTimeZone(tzGMT);
			return(dateFormat.format(instant));
		}
		catch (Exception e) {
			return ("");
		}
	}
    /**
     * Convert degree, minute, second to degree.fraction.
     * By convention, if degrees is zero, a negative sign, if any,
     * is attached attached to the minute value.
     * @param	degree			Degrees (West is negative)
     * @param	minute			Minutes
     * @param	second			Seconds
     * @return	The corresponding value. For example, 0,-30,0 yields -0.5
     */
    public static double dms(
    		int					degree,
    		int					minute,
    		int					second
    	)
    {
    	return (hms(degree, minute, second));
    }
    /**
     * Convert hours, minute, second to hours.fraction.
     * @param	hours			Hours
     * @param	minute			Minutes
     * @param	second			Seconds
     * @return	The corresponding value. For example, 6,30,0 yields 6.5
     */
    public static double hms(
    		int					hour,
    		int					minute,
    		int					second
    	)
    {
    	return (hms(hour, minute, (double) second));
    }
    /**
     * Convert hours, minute, second to hours.fraction.
     * @param	hours			Hours
     * @param	minute			Minutes
     * @param	second			Seconds
     * @return	The corresponding value. For example, 6,30,0 yields 6.5
     */
    public static double hms(
    		int					hour,
    		int					minute,
    		double				second
    	)
    {
    	return (
    			((double) hour)
    		+	(((double) minute) / 60.0)
    		+	(second / 3600.0)
    		);
    }
    /**
     * Convert a fractional degree value to its string representation.
     * @param value		A fractional degree.
     * @param tag		Either "WE" or "NS"
     * @result			The string representation. For example, 90.5
     *					yields N90Á30'"
     */
	public static String dm(
    		double				value,
    		String				tag
    	)
	{
		StringBuffer text = new StringBuffer(dm(Math.abs(value)));
		if (value == 0.0)
			;
		else if (value > 0.0)
			text.insert(0, tag.charAt(0));
		else {
			text.insert(0, tag.charAt(1));
		}
		return (text.toString());
	}
    /**
     * Convert a fractional degree value to its string representation.
     * @param value		A fractional degree.
     * @param tag		Either "WE" or "NS"
     * @result			The string representation. For example, 90.5
     *					yields W90Á30'00"
     */
	public static String dms(
    		double				value,
    		String				tag
    	)
	{
		StringBuffer text = new StringBuffer(dms(Math.abs(value)));
		if (value == 0.0)
			;
		else if (value > 0.0)
			text.insert(0, tag.charAt(0));
		else {
			text.insert(0, tag.charAt(1));
		}
		return (text.toString());
	}
    /**
     * Convert a fractional degree value to its string representation.
     * @param value	A fractional degree.
     * @result		The string representation. For example, 90.5
     *			yields 90Á30'"
     */
    public static String dm(
    		double				value
    	)
    {
		boolean			isNegative = (value < 0.0);
		if (isNegative)
			value = (-value);
		int	degree			= (int) Math.floor(value);
		value 				= (value - ((double) degree)) * 60.0;
		int	minute			= (int) Math.floor(value);
		int	second			= (int) ((value - (double) minute) * 60.0);
		if (second > 30 || second == 30 && (minute & 0x01) == 1) {
			++minute;
		}
		if (minute >= 60) {
			++degree;
			minute -= 60;
		}
		if (isNegative) {
			if (degree > 0)
				degree = (-degree);
			else if (minute > 0)
				minute = (-minute);
		}
		StringBuffer	result = new StringBuffer()
			.append(Format.format(degree, ' ', 4, 0, degreeSign))
			.append(Format.format(minute, '0', 2, 0, minuteSign)); 
		return (result.toString());
	}
    /**
     * Convert a fractional degree value to its string representation.
     * @param value		A fractional degree.
     * @result			The string representation. For example, 90.5
     *					yields 90Á30'00"
     */
    public static String dms(
    		double				value
    	)
    {
		boolean			isNegative = (value < 0.0);
		if (isNegative)
			value = (-value);
		int	degree		= (int) Math.floor(value);
		value 			= (value - (double) degree) * 60.0;
		int	minute		= (int) Math.floor(value);
		int	second		= (int) ((value - (double) minute) * 60.0);
		if (isNegative) {
			if (degree > 0)
				degree = (-degree);
			else if (minute > 0)
				minute = (-minute);
			else second = (-second);
		}

		StringBuffer	result = new StringBuffer()
			.append(Format.format(degree, ' ', 4, degreeSign))
			.append(Format.format(minute, '0', 2, minuteSign))
			.append(Format.format(second, '0', 4, secondSign)); 
		return (result.toString());
	}
    /**
     * Convert a fractional hour value to its string representation.
     * @param value		A fractional hour.
     * @result			The string representation. For example, 12.5
     *					yields 12:30:00
     */
	public static String hms(
			double			value
		)
	{
		return (hms(value, 0, CIVIL_FORMAT));
	}
    /**
     * Convert a fractional hour value to its string representation
     * using an astronomical format convention.
     * @param value		A fractional hour.
     * @result			The string representation. For example, 12.5
     *					yields 12h30m00.0s
     */
	public static String hmsAstro(
			double			value
		)
	{
		return (hms(value, 1, ASTRO_FORMAT));
	}
    /**
     * Convert a fractional hour value to its string representation
     * using either a civil or astronomical format convention.
     * @param value		A fractional hour.
     * @param secondPrecision The number of digits of precision for the
     *					seconds.
     * @param isCivil	Either Astro.CIVIL_FORMAT or Astro.ASTRO_FORMAT
     *					to distingish between 12:00:00 and 12h00m00s.
     * @result			The string representation.
     */
	public static String hms(
			double			value,
			int				secondPrecision,
			boolean			isCivil
		)
	{
		int		second		= (int) Math.floor(value * 3600.0);
		double	fract		= (value * 3600.0) - (double) second;
		if (secondPrecision == 0) {
			if (fract > 0.5 || fract == 0.5 && (second & 0x01) == 1) {
				++second;
			}
		}
		int		hour		= second / 1440;
				second		%= 1440;
		int		minute		= second / 60;
				second		%= 60;
		char	hourChar	= (isCivil) ? ':' : 'h';
		char	minuteChar	= (isCivil) ? ':' : 'm';
		char	secondChar	= (isCivil) ? Format.NO_CHAR : 's';		
		StringBuffer	result = new StringBuffer()
			.append(Format.format(hour,	'0', 2, hourChar))
			.append(Format.format(minute,	'0', 2, minuteChar));
		if (secondPrecision == 0) {
			result.append(Format.format(second,	'0', 2, secondChar));
		}
		else {
			fract += (double) second;
			result.append(Format.format(fract, '0', 2, secondPrecision, secondChar));
		}
		return (result.toString());
	}
    /**
     * Convert a fractional hour value to its string representation
     * @param value		A fractional hour.
     * @result			The string representation (hours and minutes only)
     */
	public static String hm(
			double			value
		)
	{
		if (value == ABOVE_HORIZON)
			return ("above");
		else if (value == BELOW_HORIZON)
			return ("below");
		else {
			int		hour		= (int) Math.floor(value);
			value				= (value - (double) hour) * 60.0;
			int		minute		= (int) (value + 0.5);
			if (minute >= 60) {
				++hour;
				minute -= 60;
			}
			if (hour >= 24) {
				hour -= 24;
			}
			StringBuffer	result = new StringBuffer()
				.append(Format.format(hour,	'0', 2, ':'))
				.append(Format.format(minute,	'0', 2, Format.NO_CHAR));
			return (result.toString());
		}
	}
	/**
	 * Convert a timezone offset to its string representation.
	 * @param	timezone	The timezone value (msec offset from Greenwich)
	 * @result				The string representation in hours and minutes
	 */
	public static String timeZoneString(
			long				timezone
		)
	{
		StringBuffer	result = new StringBuffer();
		timezone	/=	60000;
		if (timezone > 0) {
			result.append(Format.format(timezone / 60, '0', 2, 0, ':'))
				.append(Format.format(timezone % 60, '0', 2))
				.append(" East");
		}
		else if (timezone == 0)
			result.append("00:00");
		else {
			timezone = (-timezone);
			result.append(Format.format(timezone / 60, '0', 2, 0, ':'))
				.append(Format.format(timezone % 60, '0', 2))
				.append(" West");
		}
		return (result.toString());
	}
};