/**
* returns next occurrence _ignoring exceptions_ or NULL if there is none/not computable
*
* NOTE: an ongoing event during $from [start, end[ is considered as next
* NOTE: for previous events on ongoing event is considered as previous
*
* NOTE: computing the next occurrence of an open end rrule can be dangerous, as it might result
* in a endless loop. Therefore we only make a limited number of attempts before giving up.
*
* @param Calendar_Model_Event $_event
* @param Tinebase_Record_RecordSet $_exceptions
* @param Tinebase_DateTime $_from
* @param Int $_which
* @return Calendar_Model_Event|NULL
*/
public static function computeNextOccurrence($_event, $_exceptions, $_from, $_which = 1)
{
if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . ' $from = ' . $_from->toString());
}
if ($_which === 0 || $_event->dtstart >= $_from && $_event->dtend > $_from) {
return $_event;
}
$freqMap = array(self::FREQ_DAILY => Tinebase_DateTime::MODIFIER_DAY, self::FREQ_WEEKLY => Tinebase_DateTime::MODIFIER_WEEK, self::FREQ_MONTHLY => Tinebase_DateTime::MODIFIER_MONTH, self::FREQ_YEARLY => Tinebase_DateTime::MODIFIER_YEAR);
$rrule = new Calendar_Model_Rrule(NULL, TRUE);
$rrule->setFromString($_event->rrule);
$from = clone $_from;
$until = clone $from;
$interval = $_which * $rrule->interval;
// we don't want to compute ourself
$ownEvent = clone $_event;
$ownEvent->setRecurId($_event->getId());
$exceptions = clone $_exceptions;
$exceptions->addRecord($ownEvent);
$recurSet = new Tinebase_Record_RecordSet('Calendar_Model_Event');
if ($_from->isEarlier($_event->dtstart)) {
if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . ' from is ealier dtstart -> given event is next occurrence');
}
return $_event;
}
$rangeDate = $_which > 0 ? $until : $from;
if (!isset($freqMap[$rrule->freq])) {
if (Tinebase_Core::isLogLevel(Zend_Log::ERR)) {
Tinebase_Core::getLogger()->err(__METHOD__ . '::' . __LINE__ . ' Invalid RRULE:' . print_r($rrule->toArray(), true));
}
throw new Calendar_Exception('Invalid freq in RRULE: ' . $rrule->freq);
}
$rangeDate->add($interval, $freqMap[$rrule->freq]);
$attempts = 0;
if ($_event->rrule_until instanceof DateTime && Tinebase_Core::isLogLevel(Zend_Log::TRACE)) {
Tinebase_Core::getLogger()->trace(__METHOD__ . '::' . __LINE__ . ' Event rrule_until: ' . $_event->rrule_until->toString());
}
while (TRUE) {
if (Tinebase_Core::isLogLevel(Zend_Log::TRACE)) {
Tinebase_Core::getLogger()->trace(__METHOD__ . '::' . __LINE__ . ' trying to find next occurrence from ' . $from->toString());
}
if ($_event->rrule_until instanceof DateTime && $from->isLater($_event->rrule_until)) {
if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . ' passed rrule_until -> no further occurrences');
}
return NULL;
}
$until = $_event->rrule_until instanceof DateTime && $until->isLater($_event->rrule_until) ? clone $_event->rrule_until : $until;
$recurSet->merge(self::computeRecurrenceSet($_event, $exceptions, $from, $until));
$attempts++;
// NOTE: computeRecurrenceSet also returns events during $from in some cases, but we need
// to events later than $from.
$recurSet = $recurSet->filter(function ($event) use($from) {
return $event->dtstart >= $from;
});
if (count($recurSet) >= abs($_which)) {
if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . " found next occurrence after {$attempts} attempt(s)");
}
break;
}
if ($attempts > count($exceptions) + 5) {
if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . " could not find the next occurrence after {$attempts} attempts, giving up");
}
return NULL;
}
$from->add($interval, $freqMap[$rrule->freq]);
$until->add($interval, $freqMap[$rrule->freq]);
}
$recurSet->sort('dtstart', $_which > 0 ? 'ASC' : 'DESC');
$nextOccurrence = $recurSet[abs($_which) - 1];
if (Tinebase_Core::isLogLevel(Zend_Log::DEBUG)) {
Tinebase_Core::getLogger()->debug(__METHOD__ . '::' . __LINE__ . ' $nextOccurrence->dtstart = ' . $nextOccurrence->dtstart->toString());
}
return $nextOccurrence;
}