//
// $Id$
// From Philippe Le Hegaret (Philippe.Le_Hegaret@sophia.inria.fr)
//
// (c) COPYRIGHT MIT and INRIA, 1997.
// Please first read the full copyright statement in file COPYRIGHT.html
// DateThread.java
// $Id$
// From Yves Lafon (ylafon@w3.org)
//
// (c) COPYRIGHT MIT and INRIA, 1997.
// Please first read the full copyright statement in file COPYRIGHT.html

package org.w3c.css.util;

import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;

public class Date {
    protected static String days[] = {"Sun", "Mon", "Tue", "Wed",
            "Thu", "Fri", "Sat"};
    protected static String months[] = {"Jan", "Feb", "Mar", "Apr",
            "May", "Jun", "Jul", "Aug",
            "Sep", "Oct", "Nov", "Dec"};
    String date = "";
    String logDate = "";
    private TimeZone tz;

    /**
     * Create a new Date
     */
    public Date() {
        tz = TimeZone.getTimeZone("GMT"); // should be UTC
    }

    /**
     * Give the Date in HTTP/1.1 preferred format
     *
     * @return A String giving the date in the right format
     */
    public synchronized String getDate() {
        computeDate();
        return date;
    }

    public synchronized String getLogDate() {
        computeDate();
        return logDate;
    }

    /**
     * Returns a string representation of the object.
     */
    public String toString() {
        computeDate();
        return date;
    }

    /**
     * The main loop which calculate the date every second
     */

    private void computeDate() {
        int day;
        int hr, mn, sec;
        StringBuilder sbdate, ldate;
        Calendar cal;

        sbdate = new StringBuilder(30);
        ldate = new StringBuilder(30);

        cal = new GregorianCalendar(tz, Locale.getDefault());
        day = cal.get(Calendar.DAY_OF_MONTH);
        hr = cal.get(Calendar.HOUR_OF_DAY);
        mn = cal.get(Calendar.MINUTE);
        sec = cal.get(Calendar.SECOND);

        // construct date according to the http/1.1 format
        sbdate.append(days[cal.get(Calendar.DAY_OF_WEEK) - 1]);
        sbdate.append(", ");
        if (day < 10)
            sbdate.append('0');
        sbdate.append(day);
        sbdate.append(' ');
        sbdate.append(months[cal.get(Calendar.MONTH)]);
        sbdate.append(' ');
        sbdate.append(cal.get(Calendar.YEAR));
        sbdate.append(' ');
        if (hr < 10)
            sbdate.append('0');
        sbdate.append(hr);
        sbdate.append(':');
        if (mn < 10)
            sbdate.append('0');
        sbdate.append(mn);
        sbdate.append(':');
        if (sec < 10)
            sbdate.append('0');
        sbdate.append(sec);
        sbdate.append(" GMT");

        // construct date according to the log date format
        if (day < 10)
            ldate.append('0');
        ldate.append(day);
        ldate.append('/');
        ldate.append(months[cal.get(Calendar.MONTH)]);
        ldate.append('/');
        ldate.append(cal.get(Calendar.YEAR));
        ldate.append(':');
        if (hr < 10)
            ldate.append('0');
        ldate.append(hr);
        ldate.append(':');
        if (mn < 10)
            ldate.append('0');
        ldate.append(mn);
        ldate.append(':');
        if (sec < 10)
            ldate.append('0');
        ldate.append(sec);
        ldate.append(" +0");


        synchronized (this) {
            date = sbdate.toString();
            logDate = ldate.toString();
        }
    }

}