package org.calum.joggerlogger;

import java.util.Calendar;
import java.util.Date;
import java.util.TimeZone;

public class ISO8601 {

    /**
     * Returns an ISO8601 valid form timestamp as a String.
     * The format is year-month-dateThour:min:sec.milliZ
     * @param timestamp the desired timestamp in milliseconds
     * @return a String.
     */
    public static String getISO8610String(long timestamp) {
        Calendar c  = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
        c.setTime(new Date(timestamp));

        String year     = String.valueOf(c.get(Calendar.YEAR));
        String month    = String.valueOf(c.get(Calendar.MONTH));
        String date     = String.valueOf(c.get(Calendar.DATE));
        String hour     = String.valueOf(c.get(Calendar.HOUR_OF_DAY));
        String min      = String.valueOf(c.get(Calendar.MINUTE));
        String sec      = String.valueOf(c.get(Calendar.SECOND));
        String milli    = String.valueOf(c.get(Calendar.MILLISECOND));

        if ( month.length() == 1 ) {
            month   = new String("0".concat(month));
        }

        if ( date.length() == 1 ) {
            date    = new String("0".concat(date));
        }

        if ( hour.length() == 1 ) {
            hour    = new String("0".concat(hour));
        }

        if ( min.length() == 1 ) {
            min     = new String("0".concat(min));
        }

        if ( sec.length() == 1 ) {
            sec     = new String("0".concat(sec));
        }

        return year + "-" + month + "-" + date + "T" + hour + ":" + min + ":" + sec + "." + milli + "Z";
    }

}