Club Drupal

<?php

/*********************************************************************************/

/*          Additional functions to use with vtimezone components                */

/*********************************************************************************/

/**

 * For use with

 * iCalcreator (kigkonsult.se/iCalcreator/index.php)

 * copyright (c) 2011 Yitzchok Lavi

 * icalcreator@onebigsystem.com

 * @version   2.22

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

/**

 * Additional functions to use with vtimezone components

 *

 * Before calling the functions, set time zone 'GMT' ('date_default_timezone_set')!

 *

 * @author Yitzchok Lavi <icalcreator@onebigsystem.com>

 *         adjusted for iCalcreator Kjell-Inge Gustafsson, kigkonsult <ical@kigkonsult.se>

 * @version 1.0.2 - 2011-02-24

 *

 */

/**

 * Returns array with the offset information from UTC for a (UTC) datetime/timestamp in the

 * timezone, according to the VTIMEZONE information in the input array.

 *

 * @param array  $timezonesarray  output from function getTimezonesAsDateArrays (below)

 * @param string $tzid            time zone identifier

 * @param mixed  $timestamp       timestamp or a UTC datetime (in array format)

 * @return array                  time zone data with keys for 'offsetHis', 'offsetSec' and 'tzname'

 *

 */

function getTzOffsetForDate($timezonesarray, $tzid, $timestamp) {

    if( is_array( $timestamp )) {

//$disp = sprintf( '%04d%02d%02d %02d%02d%02d', $timestamp['year'], $timestamp['month'], $timestamp['day'], $timestamp['hour'], $timestamp['min'], $timestamp['sec'] ); // test ###

      $timestamp = gmmktime(

            $timestamp['hour'],

            $timestamp['min'],

            $timestamp['sec'],

            $timestamp['month'],

            $timestamp['day'],

            $timestamp['year']

            ) ;

    }

    $tzoffset = array();

    // something to return if all goes wrong (such as if $tzid doesn't find us an array of dates)

    $tzoffset['offsetHis'] = '+0000';

    $tzoffset['offsetSec'] = 0;

    $tzoffset['tzname']    = '?';

    if( !isset( $timezonesarray[$tzid] ))

      return $tzoffset;

    $tzdatearray = $timezonesarray[$tzid];

    if ( is_array($tzdatearray) ) {

        sort($tzdatearray); // just in case

        if ( $timestamp < $tzdatearray[0]['timestamp'] ) {

            // our date is before the first change

            $tzoffset['offsetHis'] = $tzdatearray[0]['tzbefore']['offsetHis'] ;

            $tzoffset['offsetSec'] = $tzdatearray[0]['tzbefore']['offsetSec'] ;

            $tzoffset['tzname']    = $tzdatearray[0]['tzbefore']['offsetHis'] ; // we don't know the tzname in this case

        } elseif ( $timestamp >= $tzdatearray[count($tzdatearray)-1]['timestamp'] ) {

            // our date is after the last change (we do this so our scan can stop at the last record but one)

            $tzoffset['offsetHis'] = $tzdatearray[count($tzdatearray)-1]['tzafter']['offsetHis'] ;

            $tzoffset['offsetSec'] = $tzdatearray[count($tzdatearray)-1]['tzafter']['offsetSec'] ;

            $tzoffset['tzname']    = $tzdatearray[count($tzdatearray)-1]['tzafter']['tzname'] ;

        } else {

            // our date somewhere in between

            // loop through the list of dates and stop at the one where the timestamp is before our date and the next one is after it

            // we don't include the last date in our loop as there isn't one after it to check

            for ( $i = 0 ; $i <= count($tzdatearray)-2 ; $i++ ) {

                if(( $timestamp >= $tzdatearray[$i]['timestamp'] ) && ( $timestamp < $tzdatearray[$i+1]['timestamp'] )) {

                    $tzoffset['offsetHis'] = $tzdatearray[$i]['tzafter']['offsetHis'] ;

                    $tzoffset['offsetSec'] = $tzdatearray[$i]['tzafter']['offsetSec'] ;

                    $tzoffset['tzname']    = $tzdatearray[$i]['tzafter']['tzname'] ;

                    break;

                }

            }

        }

    }

    return $tzoffset;

}

/**

 * Returns an array containing all the timezone data in the vcalendar object

 *

 * @param object $vcalendar  iCalcreator calendar instance

 * @return array             time zone transition timestamp, array before(offsetHis, offsetSec), array after(offsetHis, offsetSec, tzname)

 *                           based on the timezone data in the vcalendar object

 *

 */

function getTimezonesAsDateArrays($vcalendar) {

    $timezonedata = array();

    while( $vtz = $vcalendar->getComponent( 'vtimezone' )) {

        $tzid       = $vtz->getProperty('tzid');

        $alltzdates = array();

        while ( $vtzc = $vtz->getComponent( 'standard' )) {

            $newtzdates = expandTimezoneDates($vtzc);

            $alltzdates = array_merge($alltzdates, $newtzdates);

        }

        while ( $vtzc = $vtz->getComponent( 'daylight' )) {

            $newtzdates = expandTimezoneDates($vtzc);

            $alltzdates = array_merge($alltzdates, $newtzdates);

        }

        sort($alltzdates);

        $timezonedata[$tzid] = $alltzdates;

    }

    return $timezonedata;

}

/**

 * Returns an array containing time zone data from vtimezone standard/daylight instances

 *

 * @param object $vtzc   an iCalcreator calendar standard/daylight instance

 * @return array         time zone data; array before(offsetHis, offsetSec), array after(offsetHis, offsetSec, tzname)

 *

 */

function expandTimezoneDates($vtzc) {

    $tzdates = array();

    // prepare time zone "description" to attach to each change

    $tzbefore = array();

    $tzbefore['offsetHis']  = $vtzc->getProperty('tzoffsetfrom') ;

    $tzbefore['offsetSec'] = iCalUtilityFunctions::_tz2offset($tzbefore['offsetHis']);

    if(( '-' != substr( (string) $tzbefore['offsetSec'], 0, 1 )) && ( '+' != substr( (string) $tzbefore['offsetSec'], 0, 1 )))

      $tzbefore['offsetSec'] = '+'.$tzbefore['offsetSec'];

    $tzafter = array();

    $tzafter['offsetHis']   = $vtzc->getProperty('tzoffsetto') ;

    $tzafter['offsetSec']  = iCalUtilityFunctions::_tz2offset($tzafter['offsetHis']);

    if(( '-' != substr( (string) $tzafter['offsetSec'], 0, 1 )) && ( '+' != substr( (string) $tzafter['offsetSec'], 0, 1 )))

      $tzafter['offsetSec'] = '+'.$tzafter['offsetSec'];

    if( FALSE === ( $tzafter['tzname'] = $vtzc->getProperty('tzname')))

      $tzafter['tzname'] = $tzafter['offsetHis'];

    // find out where to start from

    $dtstart = $vtzc->getProperty('dtstart');

    $dtstarttimestamp = mktime(

            $dtstart['hour'],

            $dtstart['min'],

            $dtstart['sec'],

            $dtstart['month'],

            $dtstart['day'],

            $dtstart['year']

            ) ;

    if( !isset( $dtstart['unparsedtext'] )) // ??

      $dtstart['unparsedtext'] = sprintf( '%04d%02d%02dT%02d%02d%02d', $dtstart['year'], $dtstart['month'], $dtstart['day'], $dtstart['hour'], $dtstart['min'], $dtstart['sec'] );

    if ( $dtstarttimestamp == 0 ) {

        // it seems that the dtstart string may not have parsed correctly

        // let's set a timestamp starting from 1902, using the time part of the original string

        // so that the time will change at the right time of day

        // at worst we'll get midnight again

        $origdtstartsplit = explode('T',$dtstart['unparsedtext']) ;

        $dtstarttimestamp = strtotime("19020101",0);

        $dtstarttimestamp = strtotime($origdtstartsplit[1],$dtstarttimestamp);

    }

    // the date (in dtstart and opt RDATE/RRULE) is ALWAYS LOCAL (not utc!!), adjust from 'utc' to 'local' timestamp

    $diff  = -1 * $tzbefore['offsetSec'];

    $dtstarttimestamp += $diff;

                // add this (start) change to the array of changes

    $tzdates[] = array(

        'timestamp' => $dtstarttimestamp,

        'tzbefore'  => $tzbefore,

        'tzafter'   => $tzafter

        );

    $datearray = getdate($dtstarttimestamp);

    // save original array to use time parts, because strtotime (used below) apparently loses the time

    $changetime = $datearray ;

    // generate dates according to an RRULE line

    $rrule = $vtzc->getProperty('rrule') ;

    if ( is_array($rrule) ) {

        if ( $rrule['FREQ'] == 'YEARLY' ) {

            // calculate transition dates starting from DTSTART

            $offsetchangetimestamp = $dtstarttimestamp;

            // calculate transition dates until 10 years in the future

            $stoptimestamp = strtotime("+10 year",time());

            // if UNTIL is set, calculate until then (however far ahead)

            if ( isset( $rrule['UNTIL'] ) && ( $rrule['UNTIL'] != '' )) {

                $stoptimestamp = mktime(

                    $rrule['UNTIL']['hour'],

                    $rrule['UNTIL']['min'],

                    $rrule['UNTIL']['sec'],

                    $rrule['UNTIL']['month'],

                    $rrule['UNTIL']['day'],

                    $rrule['UNTIL']['year']

                    ) ;

            }

            $count = 0 ;

            $stopcount = isset( $rrule['COUNT'] ) ? $rrule['COUNT'] : 0 ;

            $daynames = array(

                        'SU' => 'Sunday',

                        'MO' => 'Monday',

                        'TU' => 'Tuesday',

                        'WE' => 'Wednesday',

                        'TH' => 'Thursday',

                        'FR' => 'Friday',

                        'SA' => 'Saturday'

                        );

            // repeat so long as we're between DTSTART and UNTIL, or we haven't prepared COUNT dates

            while ( $offsetchangetimestamp < $stoptimestamp && ( $stopcount == 0 || $count < $stopcount ) ) {

                // break up the timestamp into its parts

                $datearray = getdate($offsetchangetimestamp);

                if ( isset( $rrule['BYMONTH'] ) && ( $rrule['BYMONTH'] != 0 )) {

                    // set the month

                    $datearray['mon'] = $rrule['BYMONTH'] ;

                }

                if ( isset( $rrule['BYMONTHDAY'] ) && ( $rrule['BYMONTHDAY'] != 0 )) {

                    // set specific day of month

                    $datearray['mday']  = $rrule['BYMONTHDAY'];

                } elseif ( is_array($rrule['BYDAY']) ) {

                    // find the Xth WKDAY in the month

                    // the starting point for this process is the first of the month set above

                    $datearray['mday'] = 1 ;

                    // turn $datearray as it is now back into a timestamp

                    $offsetchangetimestamp = mktime(

                        $datearray['hours'],

                        $datearray['minutes'],

                        $datearray['seconds'],

                        $datearray['mon'],

                        $datearray['mday'],

                        $datearray['year']

                            );

                    if ($rrule['BYDAY'][0] > 0) {

                        // to find Xth WKDAY in month, we find last WKDAY in month before

                        // we do that by finding first WKDAY in this month and going back one week

                        // then we add X weeks (below)

                        $offsetchangetimestamp = strtotime($daynames[$rrule['BYDAY']['DAY']],$offsetchangetimestamp);

                        $offsetchangetimestamp = strtotime("-1 week",$offsetchangetimestamp);

                    } else {

                        // to find Xth WKDAY before the end of the month, we find the first WKDAY in the following month

                        // we do that by going forward one month and going to WKDAY there

                        // then we subtract X weeks (below)

                        $offsetchangetimestamp = strtotime("+1 month",$offsetchangetimestamp);

                        $offsetchangetimestamp = strtotime($daynames[$rrule['BYDAY']['DAY']],$offsetchangetimestamp);

                    }

                    // now move forward or back the appropriate number of weeks, into the month we want

                    $offsetchangetimestamp = strtotime($rrule['BYDAY'][0] . " week",$offsetchangetimestamp);

                    $datearray = getdate($offsetchangetimestamp);

                }

                // convert the date parts back into a timestamp, setting the time parts according to the

                // original time data which we stored

                $offsetchangetimestamp = mktime(

                    $changetime['hours'],

                    $changetime['minutes'],

                    $changetime['seconds'] + $diff,

                    $datearray['mon'],

                    $datearray['mday'],

                    $datearray['year']

                        );

                // add this change to the array of changes

                $tzdates[] = array(

                    'timestamp' => $offsetchangetimestamp,

                    'tzbefore'  => $tzbefore,

                    'tzafter'   => $tzafter

                    );

                // update counters (timestamp and count)

                $offsetchangetimestamp = strtotime("+" . (( isset( $rrule['INTERVAL'] ) && ( $rrule['INTERVAL'] != 0 )) ? $rrule['INTERVAL'] : 1 ) . " year",$offsetchangetimestamp);

                $count += 1 ;

            }

        }

    }

    // generate dates according to RDATE lines

    while ($rdates = $vtzc->getProperty('rdate')) {

        if ( is_array($rdates) ) {

            foreach ( $rdates as $rdate ) {

                // convert the explicit change date to a timestamp

                $offsetchangetimestamp = mktime(

                        $rdate['hour'],

                        $rdate['min'],

                        $rdate['sec'] + $diff,

                        $rdate['month'],

                        $rdate['day'],

                        $rdate['year']

                        ) ;

                // add this change to the array of changes

                $tzdates[] = array(

                    'timestamp' => $offsetchangetimestamp,

                    'tzbefore'  => $tzbefore,

                    'tzafter'   => $tzafter

                    );

            }

        }

    }

    return $tzdates;

}