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| 1 | +<?php |
| 2 | + |
| 3 | +declare(strict_types=1); |
| 4 | + |
| 5 | +/** |
| 6 | + * @copyright 2022 Anna Larch <[email protected]> |
| 7 | + * |
| 8 | + * @author 2022 Anna Larch <[email protected]> |
| 9 | + * |
| 10 | + * @license GNU AGPL version 3 or any later version |
| 11 | + * |
| 12 | + * This program is free software: you can redistribute it and/or modify |
| 13 | + * it under the terms of the GNU Affero General Public License as |
| 14 | + * published by the Free Software Foundation, either version 3 of the |
| 15 | + * License, or (at your option) any later version. |
| 16 | + * |
| 17 | + * This program is distributed in the hope that it will be useful, |
| 18 | + * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 19 | + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 20 | + * GNU Affero General Public License for more details. |
| 21 | + * |
| 22 | + * You should have received a copy of the GNU Affero General Public License |
| 23 | + * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 24 | + * |
| 25 | + */ |
| 26 | +namespace OCA\DAV\CalDAV; |
| 27 | + |
| 28 | +use OCA\DAV\AppInfo\Application; |
| 29 | +use OCA\DAV\CalDAV\Schedule\IMipService; |
| 30 | +use OCP\AppFramework\Utility\ITimeFactory; |
| 31 | +use OCP\IConfig; |
| 32 | +use Sabre\VObject\Component\VCalendar; |
| 33 | +use Sabre\VObject\Component\VEvent; |
| 34 | +use Sabre\VObject\Component\VTimeZone; |
| 35 | +use Sabre\VObject\Component\VTodo; |
| 36 | +use function max; |
| 37 | + |
| 38 | +class EventComparisonService { |
| 39 | + |
| 40 | + /** @var string[] */ |
| 41 | + private const EVENT_DIFF = [ |
| 42 | + 'RECURRENCE-ID', |
| 43 | + 'RRULE', |
| 44 | + 'SEQUENCE', |
| 45 | + 'LAST-MODIFIED' |
| 46 | + ]; |
| 47 | + |
| 48 | + |
| 49 | + /** |
| 50 | + * If found, remove the event from $eventsToFilter that |
| 51 | + * is identical to the passed $filterEvent |
| 52 | + * and return whether an identical event was found |
| 53 | + * |
| 54 | + * This function takes into account the SEQUENCE, |
| 55 | + * RRULE, RECURRENCE-ID and LAST-MODIFIED parameters |
| 56 | + * |
| 57 | + * @param VEvent $filterEvent |
| 58 | + * @param array $eventsToFilter |
| 59 | + * @return bool true if there was an identical event found and removed, false if there wasn't |
| 60 | + */ |
| 61 | + private function removeIfUnchanged(VEvent $filterEvent, array &$eventsToFilter): bool { |
| 62 | + $filterEventData = []; |
| 63 | + foreach(self::EVENT_DIFF as $eventDiff) { |
| 64 | + $filterEventData[] = IMipService::readPropertyWithDefault($filterEvent, $eventDiff, ''); |
| 65 | + } |
| 66 | + |
| 67 | + /** @var VEvent $component */ |
| 68 | + foreach ($eventsToFilter as $k => $eventToFilter) { |
| 69 | + $eventToFilterData = []; |
| 70 | + foreach(self::EVENT_DIFF as $eventDiff) { |
| 71 | + $eventToFilterData[] = IMipService::readPropertyWithDefault($eventToFilter, $eventDiff, ''); |
| 72 | + } |
| 73 | + // events are identical and can be removed |
| 74 | + if (empty(array_diff($filterEventData, $eventToFilterData))) { |
| 75 | + unset($eventsToFilter[$k]); |
| 76 | + return true; |
| 77 | + } |
| 78 | + } |
| 79 | + return false; |
| 80 | + } |
| 81 | + |
| 82 | + /** |
| 83 | + * Compare two VCalendars with each other and find all changed elements |
| 84 | + * |
| 85 | + * Returns an array of old and new events |
| 86 | + * |
| 87 | + * Old events are only detected if they are also changed |
| 88 | + * If there is no corresponding old event for a VEvent, it |
| 89 | + * has been newly created |
| 90 | + * |
| 91 | + * @param VCalendar $new |
| 92 | + * @param VCalendar|null $old |
| 93 | + * @return array<string, VEvent[]> |
| 94 | + */ |
| 95 | + public function findModified(VCalendar $new, ?VCalendar $old): array { |
| 96 | + $newEventComponents = $new->getComponents(); |
| 97 | + |
| 98 | + foreach ($newEventComponents as $k => $event) { |
| 99 | + if(!$event instanceof VEvent) { |
| 100 | + unset($newEventComponents[$k]); |
| 101 | + } |
| 102 | + } |
| 103 | + |
| 104 | + if(empty($old)) { |
| 105 | + return ['old' => null, 'new' => $newEventComponents]; |
| 106 | + } |
| 107 | + |
| 108 | + $oldEventComponents = $old->getComponents(); |
| 109 | + if(is_array($oldEventComponents) && !empty($oldEventComponents)) { |
| 110 | + foreach ($oldEventComponents as $k => $event) { |
| 111 | + if(!$event instanceof VEvent) { |
| 112 | + unset($oldEventComponents[$k]); |
| 113 | + continue; |
| 114 | + } |
| 115 | + if($this->removeIfUnchanged($event, $newEventComponents)) { |
| 116 | + unset($oldEventComponents[$k]); |
| 117 | + } |
| 118 | + } |
| 119 | + } |
| 120 | + |
| 121 | + return ['old' => array_values($oldEventComponents), 'new' => array_values($newEventComponents)]; |
| 122 | + } |
| 123 | +} |
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