/**
 * SunClockData holds the data that controls all displays.<p>
 *
 * 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 1.2
 * 1996.09.27
 * Set tabs every 4 characters.
 */

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

public class SunClockData extends Observable implements Constants
{
	/**
	 * This hack is needed to pass the applet to a dialog via
	 * an ActionListener.
	 */
	SunClockApplet		sunClockApplet;
	/**
	 * The current instant is defined by two values: the Java date
	 * as returned by the operating system and the actual timezone
	 * offset, initialized to the system timezone and, potentially,
	 * overriden by the applet page or user dialog.
	 */
	private Date		javaDate	= new Date();
	private TimeZone	timeZone	= TimeZone.getDefault();
	/**
	 * The current observer's location. North latitude and East longitude
	 * are positive, South and West are negative. locationName is null
	 * if the location is unknown.
	 */
	private double	latitude		= 0.0;
	private double	longitude		= 0.0;
	private String	locationName	= "A Wet Spot in the Middle of the Atlantic Ocean";

	/**
	 * Layout information (here, so it's in one place).
	 */
	private Font		displayFont		= new Font("SansSerif", Font.PLAIN, 10);
	
	/**
	 * This may be set true to supress the hour chime.
	 */
	private boolean		silentFlag		= false;
	
	/**
	 * lastMoonChange and lastSunChange are the times (Java epoch)
	 * when the object was last updated. These values are not exported.
	 */
	private long	lastMoonChange	= 0;
	private long	lastSunChange	= 0;
	
	/*
	 * These parameters determine display update frequency. They are in
	 * getTime values (milliseconds)
	 */
	private static final long	MOON_INTERVAL	=  4L * 60L * 60000L;	/* Four hours	*/
	private static final double SUN_INTERVAL	=       15L * 60000L;	/* 15 minutes	*/

	public SunClockData(
			SunClockApplet		sunClockApplet
		)
	{
		super();
		this.sunClockApplet	= sunClockApplet;
	}
	public SunClockApplet	getSunClockApplet()
	{
		return (sunClockApplet);
	}
	public void setDisplayFont(
			Font			displayFont
		)
	{
		this.displayFont	= displayFont;
		setChanged();
		notifyObservers(new Integer(DISPLAY_FONT_CHANGED));
	}
	public Font	getDisplayFont()
	{
		return (displayFont);
	}
	public void setSilentFlag(
			boolean			silentFlag
		)
	{
		this.silentFlag		= silentFlag;
	}
	public boolean getSilentFlag()
	{
		return (silentFlag);
	}
	/**
	 * setLocation (called by SunImageCanvas)
	 */
	public void setLocation(
			double			latitude,
			double			longitude
		)
	{
		TimeZone newZone	= CityList.findNearestTimezone(
					latitude, longitude
				);
		if (newZone == null) {
			newZone			= timeZone;
		}
		setLocation(null, latitude, longitude, newZone);
	}
	public void setLocation(
			String			locationName,
			double			latitude,
			double			longitude,
			TimeZone		timeZone
		)
	{
		this.locationName		= locationName;
		this.latitude			= latitude;
		this.longitude			= longitude;
		if (timeZone == null) {
			timeZone			= TimeZone.getDefault();
		}
		this.timeZone			= timeZone;
		setChanged();
		notifyObservers(new Integer(LOCATION_CHANGED | TIME_CHANGED));
	}
	public void setDate(
			Date			javaDate
		)
	{
		this.javaDate		= javaDate;
		long now			= javaDate.getTime();
		int whatChanged		= TIME_CHANGED;
		if ((now - lastMoonChange) >= MOON_INTERVAL) {
			whatChanged		|= MOON_UPDATE_NEEDED;
			lastMoonChange = now;
		}
		if ((now - lastSunChange) >= SUN_INTERVAL) {
			whatChanged		|= SUN_UPDATE_NEEDED;
			lastSunChange = now;

		}
		setChanged();
		notifyObservers(new Integer(whatChanged));
	}
	/**
	 * The stop method will shut down all child processes. It
	 * is called from stop() in the applet.
	 */
	public void stop()
	{
		setChanged();
		notifyObservers(new Integer(STOP_NOW));
	}
	public double getLatitude()
	{
		return (latitude);
	}
	public double getLongitude()
	{
		return (longitude);
	}
	public String getLocationName()
	{
		if (locationName == null)
			return ("");
		else {
			return (locationName);
		}
	}
	/**
	 * Return the timezone offset in msec East of Greenwich.
	 */
	public long getTimeZoneOffset()
	{
		return (Astro.getTimeZoneOffset(javaDate, timeZone));
	}
	/**
	 * Return the Java date.
	 */
	public Date getJavaDate()
	{
		return (javaDate);
	}
	/**
	 * Return the selected timezone
	 */
	public TimeZone getTimeZone()
	{
		return (timeZone);
	}
	public String getTimeZoneID()
	{
		return (timeZone.getID());
	}
	/**
	 * Change the timezone
	 */
	public void setTimeZone(
			TimeZone		timeZone
		)
	{
		this.timeZone		= timeZone;
		setChanged();
		notifyObservers(new Integer(TIME_CHANGED));
	}	
	/**
	 * Return the date for the user-specified timezone
	 */
	public String getLocalDateString()
	{
		return (AstroFormat.getLocalDateString(javaDate, timeZone));
	}
	public String getGMTDateString()
	{
		return (AstroFormat.getGMTDateString(javaDate));
	}
	public String getLatLongString()
	{
		String locationText =
			((locationName == null) ? "" : locationName + ": ")
			+ AstroFormat.dm(latitude, "NS")
			+ " "
			+ AstroFormat.dm(longitude, "EW")
			+ ", timezone  "
			+ AstroFormat.timeZoneString(getTimeZoneOffset())
			+ " (" + timeZone.getID() + ")"
			;
		return (locationText.toString());
	}
	public String toString()
	{
		return (getLatLongString() + ", " + getLocalDateString());
	}
}