/**
 * This is class implements a clock, which can display time is various 
 * formats. Specifically it displays Greenwich Mean Time (UTC),
 * local time (e.g. EST), or the local sidereal time, based on your
 * longitude.
 * Note that this class uses some of the depreciated interfaces to the
 * java.util.Date class.
 *
 * @version $Id: jlstclk.java,v 3.10 2003/09/25 15:56:17 jbrandt Exp jbrandt $
 * @author Joe Brandt, National Radio Astronomy Observatory, jbrandt@nrao.edu
 * @see http://www.gb.nrao.edu/~jbrandt
 *
 */
 
 /**
 * This class can be run either as an application, or as an applet, although
 * the latter is not well tested.
 * Available parameters are:
 *     lstfmt : A @see DateFormat style string, defaults to "HH:mm:ss 'LST'".
 *         If yyyyy is specified, the Modified Julian Day is displayed.
 *     utcfmt : Same as above, for UTC time display
 *     localfmt: Same as above for local time display
 *     longitude: A decimal and fraction of the degrees West of Greenwich, England.
 *     font : A name of the desired font. Defaults to "TimesRoman".
 *     mode : The initial time display mode. Defaults to "lst".
 *     fontsize : The font size number (e.g. 12, 14 etc.)
 *     foregroundcolor : A color name for the text display
 *     backgroundcolor : The background color name
 *
 */
 

import java.awt.*;
import java.awt.event.*;
import java.util.Date;
import java.util.TimeZone;
import java.text.*;

public class jlstclk extends java.applet.Applet 
    implements Runnable, MouseListener, KeyListener, ActionListener
{

    Font theFont;
    Date theDate;
    Date lstDate;
    Double longitude;
    double longitudeRads;
    Thread runner;
    int xposition;
    int yposition;
    String xcoord;
    String ycoord;
    String localZone;
    Image offscreenImage;
    Graphics offscreenGraphics;
    static boolean initialzed = false;
    String mainArgs[];
    static boolean inAnApplet = true;
    Frame f;
    SimpleDateFormat utcFormat;
    SimpleDateFormat lstFormat;
    SimpleDateFormat localFormat;
    String longitudeStr;
    String utcfmtStr;
    String lstfmtStr;
    String localfmtStr;
    String modeStr;
    String bgcolor;
    String fgcolor;
    String theFontName;
    String fontSizeStr;
    FontMetrics fontMetrics;
	int displayMode = 1;
	int curWidth = 0;
	int curHeight = 0;
	int theFontSize;
	PopupMenu menu;
	
    public jlstclk()
    {
        // sane defaults
        lstfmtStr=" HH:mm:ss 'LST' ";
        utcfmtStr=" HH:mm:ss 'UTC' ";
        localfmtStr=" HH:mm:ss ";
        // inAnApplet = true;
        displayMode = 1;
        modeStr = "lst";
        curWidth = 0;
        curHeight = 0;
    }


  public void init()
  {
    addMouseListener(this);
    addKeyListener(this);

    // Set the background and foreground colors
    if(inAnApplet)
    {
        bgcolor = getParameter("backgroundcolor");
        fgcolor = getParameter("foregroundcolor");
        modeStr = getParameter("mode");
        lstfmtStr=getParameter("lstfmt");
        if(lstfmtStr == null)
            lstfmtStr=" HH:mm:ss 'LST' ";
        utcfmtStr=getParameter("utcfmt");
        if(utcfmtStr == null)
            utcfmtStr=" HH:mm:ss 'UTC' ";
        localfmtStr=getParameter("localfmt");
        if(localfmtStr == null)
            localfmtStr=" HH:mm:ss ";
    }
    else
    {
        bgcolor="white";
        fgcolor="red";
    }
    
    if(modeStr == null)
    {
        displayMode=1;
    }
    else if(modeStr.equals("lst"))
    {
        displayMode=1;
    }
    else if(modeStr.equals("utc"))
    {
        displayMode=2;
    }
    else if(modeStr.equals("local"))
    {
        displayMode=3;
    }
    else
        displayMode=1;

    utcFormat = new SimpleDateFormat(utcfmtStr);
    utcFormat.setTimeZone(TimeZone.getTimeZone("GMT"));
    // DEBUG utcFormat.setTimeZone(TimeZone.getDefault());
    // Set the LST one to the local zone, so no offset are made
    lstFormat = new SimpleDateFormat(lstfmtStr);
    lstFormat.setTimeZone(TimeZone.getDefault());
    localFormat = new SimpleDateFormat(localfmtStr);
    localFormat.setTimeZone(TimeZone.getDefault());
    
    
    // setup defaults
    setBackground(Color.white);
    setForeground(Color.black);

    if (bgcolor.equals("white"))
        setBackground(Color.white);

    if (bgcolor.equals("black"))
        setBackground(Color.black);

    if (bgcolor.equals("red"))
        setBackground(Color.red);

    if (bgcolor.equals("green"))
        setBackground(Color.green);

    if (bgcolor.equals("blue"))
        setBackground(Color.blue);

    if (bgcolor.equals("yellow"))
        setBackground(Color.yellow);

    if (fgcolor.equals("white"))
        setForeground(Color.white);

    if (fgcolor.equals("black"))
        setForeground(Color.black);

    if (fgcolor.equals("red"))
        setForeground(Color.red);

    if (fgcolor.equals("green"))
        setForeground(Color.green);

    if (fgcolor.equals("blue"))
        setForeground(Color.blue);

    if (fgcolor.equals("yellow"))
        setForeground(Color.yellow);

    // Get font info from the APPLET Tag and assign

    if(inAnApplet)
    {
        theFontName = getParameter("fontname");
    }

    if (theFontName == null)
        theFontName = "TimesRoman";

    if(inAnApplet)
        fontSizeStr = getParameter("fontsize");

    if (fontSizeStr == null)
        theFontSize = 12;
    else
        theFontSize = Integer.parseInt(fontSizeStr);

    theFont = new Font(theFontName, Font.BOLD, theFontSize);

    // Get x y coordinate info from applet tag and assign

    if(inAnApplet)
    {
        xcoord = getParameter("xcoord");
        ycoord = getParameter("ycoord");
    }
    else
    {
        xcoord = "center";
        ycoord = "center";
    }

    // Get longitude for LST calculations and convert to radians
    if(inAnApplet)
    {
        longitudeStr = getParameter("longitude");
    }

    if(longitudeStr != null)
    {
        longitude = Double.valueOf(longitudeStr);
    }
    else
    {
        longitude = Double.valueOf("0.0");
    }

    longitudeRads = Math.PI*longitude.doubleValue()/180.0;

    // Get the local Time zone string
    localZone = TimeZone.getDefault().getID();
    if(localZone == null)
        localZone = " ";

    fontMetrics = getFontMetrics(theFont);

    int tWidth1 = 0, tWidth2=0, tWidth3=0;
    int tHeight = fontMetrics.getHeight();
    if(utcfmtStr != null)
        tWidth1 = fontMetrics.stringWidth(utcfmtStr);
    if(lstfmtStr != null)
        tWidth2 = fontMetrics.stringWidth(lstfmtStr);
    if(localfmtStr != null)
        tWidth3 = fontMetrics.stringWidth(localfmtStr);

    tWidth1=Math.max(tWidth1,Math.max(tWidth2, tWidth3));
    tWidth1 += 50;
    tHeight += 30;
    // System.out.println("wxH " + Integer.toString(tWidth1) + " " + Integer.toString(tHeight));
    doResize(tWidth1, tHeight);
    
    setVisible(true);
    if(!inAnApplet)
    {
        menu = new PopupMenu();
        menu.add("Display LST");
        menu.add("Display UTC");
        menu.add("Display Local");
        menu.add("Exit");
        f.add(menu);
        menu.addActionListener(this);
        menu.addNotify();
    }
    initialzed = true; 
  }
         

  public static void main(String[] argv) {
    jlstclk.inAnApplet = false;
    jlstclk v = new jlstclk();
    v.mainArgs = argv;

    v.f = new Frame("jLSTclock $Revision: 3.10 $");
    v.f.add("Center", v);
    v.f.setSize(200,100);
    v.f.setVisible(true);

    int i;
    

    // Parse command line options
    for(i=0; i<argv.length; i++)
    {
        // System.out.println(argv[i]);

        if(argv[i].startsWith("longitude="))
        {
            v.longitudeStr=argv[i].substring(10);
        }
        else if(argv[i].startsWith("utcfmt="))
        {
            v.utcfmtStr=argv[i].substring(7);
            v.utcfmtStr=v.utcfmtStr.replace('_', (char)0x27);
        }
        else if(argv[i].startsWith("lstfmt="))
        {
            v.lstfmtStr=argv[i].substring(7);
            v.lstfmtStr=v.lstfmtStr.replace((char)0x5f, (char)0x27);
        }
        else if(argv[i].startsWith("mode="))
        {
            v.modeStr=argv[i].substring(5);
        }
        else if(argv[i].startsWith("font="))
        {
            v.theFontName=argv[i].substring(5);
        }
        else if(argv[i].startsWith("fontsize="))
        {
            v.fontSizeStr=argv[i].substring(9);
        }
        else if(argv[i].startsWith("background="))
        {
            v.bgcolor=argv[i].substring(11);
        }
        else if(argv[i].startsWith("foreground="))
        {
            v.fgcolor=argv[i].substring(11);
        }
	else if(argv[i].equals("lstonly"))
	{
	    v.lstfmtStr=" HH:mm:ss 'LST' ";
	    v.utcfmtStr=" HH:mm:ss 'UTC' ";
	    v.localfmtStr=" HH:mm:ss ";
	}
        else
        {
System.out.println("jlstclk: understands the following flags");
System.out.println("\t[longitude=xx.xx] optional, in degrees west");
System.out.println("\t[utcfmt=formatspec] (if null no utc display)");
System.out.println("\t[lstfmt=formatspec] (if null no lst display)");
System.out.println("\t[mode=(lst|utc|local)] (if null lst displayed)");
System.out.println("\t[font=name] optional e.g. TimesRoman");
System.out.println("\t[fontsize=size] optional e.g. 18");
System.out.println("\t[background=color] optional e.g. white");
System.out.println("\t[foreground=color] optional e.g. red");
            System.exit(0);
        }
    }

    v.init();
    v.start();
  }


public String getAppletInfo()
{
    return "LST Clock Applet, $Revision: 3.10 $ by J. Brandt";
}


public void start()
{
    // Create a new thread
    if (runner == null); {
        runner = new Thread(this);
        runner.start();
    }
}

public void stop()
{
    //set the thread to null for garbage collector
    if (runner != null); {
        runner.stop();
        runner = null;
    }
}

public void run()
{
    Thread me = Thread.currentThread();

    me.setPriority(Thread.MIN_PRIORITY);
    
    // Loop infinitely every second and paint current date time to the container evry loop

    while (true)
    {
        if(initialzed == true)
            repaint();
        try
        {
            Thread.sleep(1000);
        }
        catch (InterruptedException e)
        {
        }
    }
}

public void doResize(int w, int h)
{
    // Create the offscreen image to implement double buffering
    offscreenImage = createImage(w, h);
    offscreenGraphics = offscreenImage.getGraphics();
    curWidth = w;
    curHeight = h;
}

public void paint(Graphics g)
{
    // This method called by repaint, which is called by run
    int utcwidth;
    int utcheight;
    int x2pos;
    int offset;

    theDate = new Date();
    String dateStr;
    
    offset = theDate.getTimezoneOffset();
    // Convert to UTC
    // theDate = new Date(offset * 60000 + theDate.getTime());
    

    // If we get here prior to the run loop, some data members
    // don't exist yet. So simply return without refering to them.
    // (Fixes NULL pointer exception on some systems.)
    if(initialzed == false)
        return;

    if(curWidth != g.getClipBounds().width || 
       curHeight != g.getClipBounds().height)
    {
       doResize(g.getClipBounds().width, g.getClipBounds().height); 
    }
    // Make theFont the current font of the off screen image
    offscreenGraphics.setFont(theFont);

    //Make the applet background color the current offscreen graphic color, then
    //paint the entire rectangle
    offscreenGraphics.setColor(getBackground());
    offscreenGraphics.fillRect(0,0,getSize().width,getSize().height);
    
    switch(displayMode)
    {
        case 1: // LST display
	    lstDate = lmst(theDate, longitudeRads);
	    dateStr = lstFormat.format(lstDate);
	break;
	case 2: // UTC display
	    dateStr = utcFormat.format(theDate);
	break;
	case 3: // Local time display
	    dateStr = localFormat.format(theDate) + localZone;
	break;
	default:
	    dateStr = "'Unknown Mode'";
	break;

    }
    xposition = (curWidth - fontMetrics.stringWidth(dateStr)) / 2;
    yposition = (curHeight/2) + (fontMetrics.getHeight()/4);

    // Now make the applet foreground color the current offscreen 
    // graphic color (in prep for painting the String)
    offscreenGraphics.setColor(getForeground());
    // draw the string on the offscreen graphic
    offscreenGraphics.drawString(dateStr, xposition,yposition);

    //paint over the applet container with the offscreen graphic
    g.drawImage(offscreenImage,0,0,this);
}

public void update(Graphics g)
{
    //Override the update method
    paint(g);
}

// Event handling section
// Implement MouseListener interface
public void mouseClicked(MouseEvent e) {}
public void mousePressed(MouseEvent e) {
    if(!inAnApplet)
        menu.show(f, 5, 5);
}
public void mouseReleased(MouseEvent e) {}
public void mouseEntered(MouseEvent e) 
{
    if(inAnApplet)
        showStatus(getAppletInfo());
    // else
        // System.out.println("LSTclock $Revision: 3.10 $ by Joe Brandt\n");
    
}
public void mouseExited(MouseEvent e) 
{
    if(inAnApplet)
        showStatus("");
    // else
        // System.out.println("LSTclock\n");
}

public void actionPerformed(ActionEvent e) {
    String cmd = e.getActionCommand();
    if(cmd.equals("Display LST")) {
        displayMode = 1;
    } else if(cmd.equals("Display UTC")) {
        displayMode = 2;
    } else if(cmd.equals("Display Local")) {
        displayMode = 3;
    } else if(cmd.equals("Exit")) {
        System.exit(0);
    }
}

// Implement KeyListener interface
public void keyPressed(KeyEvent e) 
{
    int tWidth1 = 0, tWidth2=0, tWidth3=0;
    int tHeight = fontMetrics.getHeight();

    switch(e.getKeyChar())
    {
    case 'q':
    case 'Q':
        System.exit(0);
    break;
    case 'r':
    if(utcfmtStr != null)
        tWidth1 = fontMetrics.stringWidth(utcfmtStr);
    if(lstfmtStr != null)
        tWidth2 = fontMetrics.stringWidth(lstfmtStr);
    if(localfmtStr != null)
        tWidth3 = fontMetrics.stringWidth(localfmtStr);

    tWidth1=Math.max(tWidth1,Math.max(tWidth2, tWidth3));
    tWidth1 += 50;
    tHeight += 30;
    doResize(tWidth1, tHeight);
    break;
    case 'l':
    case 'L':
        displayMode = 1;
	if(lstfmtStr == null)
	    lstfmtStr = " HH:mm:ss 'LST' ";
    break;
    case 'u':
    case 'U':
        displayMode = 2;
	if(utcfmtStr == null)
	    utcfmtStr = " HH:mm:ss 'UTC' ";
    break;
    case 't':
    case 'T':
        displayMode = 3;
	if(localfmtStr == null)
	    localfmtStr = " HH:mm:ss " + "'" + localZone + "'";
    break;
    case '+':
        theFontSize += 2;
        theFont = new Font(theFontName, Font.BOLD, theFontSize);
	if(theFont == null)
	{
	    theFontSize -= 2;
	    theFont = new Font(theFontName, Font.BOLD, theFontSize);
	}
	fontMetrics = getFontMetrics(theFont);
	offscreenGraphics.setFont(theFont);
    break;
    case '-':
        if(theFontSize > 2)
            theFontSize -= 2;
        theFont = new Font(theFontName, Font.BOLD, theFontSize);
	if(theFont == null)
	{
	    theFontSize -= 2;
	    theFont = new Font(theFontName, Font.BOLD, theFontSize);
	}
	fontMetrics = getFontMetrics(theFont);
	offscreenGraphics.setFont(theFont);
    break;
    default:
    break;
    }
}
public void keyReleased(KeyEvent e) {}
public void keyTyped(KeyEvent e) {}

// Return local siderial time in radians
public Date
lmst(Date localDate, double observerLongitude)
{
    double tu;
    double gmst;
    double LST;
    double ut1;
    double dmjd;
    long imjd;
    int offset;
    int hours, day, month, year;
    Date lstTime;

    // Get correction in minutes between local and GMT time
    // (e.g. calculate UTC from Civil time)
    offset = localDate.getTimezoneOffset();

    imjd = mjd(localDate);

    // get ut1 (really UTC) in turns
    ut1 = (localDate.getSeconds() + (localDate.getMinutes() + offset) * 60 +
           localDate.getHours()*3600)/86400.0;



    // If ut rolled over, means UTC on next day
    if(ut1 > 1.0)
    {
        ut1 -= 1.0;
        imjd += 1;
    }

    dmjd = (double)imjd + ut1;
    lstTime = localDate;

    // Julian centuries from fundamental epoch J2000 to this UT
    tu = (dmjd - 51544.5) / 36525.0;

    // tu is in turns
    // GMST at this UT in radians
    gmst = ( ut1 * (2.0*Math.PI) +
             ( 24110.54841 +
             ( 8640184.812866 +
             ( 0.093104 - ( 6.2e-6 * tu ) ) * tu ) * tu ) * Math.PI/43200.0 );

    // correct for observer longitude
    LST = gmst - observerLongitude;

    // assure a positive answer, between 0 and 2PI
    while(LST < 0.0) {
        LST += 2.0*Math.PI;
    }
    while(LST > 2.0*Math.PI) {
        LST -= 2.0*Math.PI;
    }

    // Convert from radians to seconds
    LST = LST * 43200.0/Math.PI;

    lstTime.setSeconds((int)LST%60);
    lstTime.setMinutes(((int)LST/60)%60);
    lstTime.setHours(((int)LST/3600));

    // A true hack but it is useful.
    // We use the year to hold the MJD value, but the formatter
    // will add 1900 to it before display, so offset it here
    lstTime.setYear((int)imjd - 1900);

    return(lstTime);
}

public long mjd(Date date)
{
long year;
long month;
long day;
long jy, jm, ja, jday;

    // getMonth range is 0..11
    month = 1 + date.getMonth();
    day = date.getDate();
    year = date.getYear() + 1900;

    jy = year;

    // Garbage in, garbage out ...
    if (jy == 0)
        return(0);

    if (jy < 0)
        ++jy;
    if (month > 2) {
        jm=month+1;
    } else {
        --jy;
        jm=month+13;
    }
    jday = (long)(Math.floor(365.25*jy)+Math.floor(30.6001*jm)+day+1720995);

    // switch over to gregorian calendar
    if (day+31L*(month+12L*year) >= (15+31L*(10+12L*1582))) {
        ja=(long)(0.01*jy);
        jday += 2-ja+(long) (0.25*ja);
    }
    return(jday-2400001);

}

// End class jlstclk
}