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[friendica.git] / src / Protocol / ActivityPub / Processor.php
1 <?php
2 /**
3  * @copyright Copyright (C) 2010-2022, the Friendica project
4  *
5  * @license GNU AGPL version 3 or any later version
6  *
7  * This program is free software: you can redistribute it and/or modify
8  * it under the terms of the GNU Affero General Public License as
9  * published by the Free Software Foundation, either version 3 of the
10  * License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU Affero General Public License for more details.
16  *
17  * You should have received a copy of the GNU Affero General Public License
18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
19  *
20  */
21
22 namespace Friendica\Protocol\ActivityPub;
23
24 use Friendica\Content\Text\BBCode;
25 use Friendica\Content\Text\HTML;
26 use Friendica\Content\Text\Markdown;
27 use Friendica\Core\Logger;
28 use Friendica\Core\Protocol;
29 use Friendica\Core\System;
30 use Friendica\Core\Worker;
31 use Friendica\Database\DBA;
32 use Friendica\DI;
33 use Friendica\Model\APContact;
34 use Friendica\Model\Contact;
35 use Friendica\Model\Conversation;
36 use Friendica\Model\Event;
37 use Friendica\Model\GServer;
38 use Friendica\Model\Item;
39 use Friendica\Model\ItemURI;
40 use Friendica\Model\Mail;
41 use Friendica\Model\Tag;
42 use Friendica\Model\User;
43 use Friendica\Model\Post;
44 use Friendica\Protocol\Activity;
45 use Friendica\Protocol\ActivityPub;
46 use Friendica\Protocol\Relay;
47 use Friendica\Util\DateTimeFormat;
48 use Friendica\Util\JsonLD;
49 use Friendica\Util\Strings;
50 use Friendica\Worker\Delivery;
51
52 /**
53  * ActivityPub Processor Protocol class
54  */
55 class Processor
56 {
57         /**
58          * Extracts the tag character (#, @, !) from mention links
59          *
60          * @param string $body
61          * @return string
62          */
63         protected static function normalizeMentionLinks(string $body): string
64         {
65                 return preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
66         }
67
68         /**
69          * Convert the language array into a language JSON
70          *
71          * @param array $languages
72          * @return string language JSON
73          */
74         private static function processLanguages(array $languages)
75         {
76                 $codes = array_keys($languages);
77                 $lang = [];
78                 foreach ($codes as $code) {
79                         $lang[$code] = 1;
80                 }
81
82                 if (empty($lang)) {
83                         return '';
84                 }
85
86                 return json_encode($lang);
87         }
88         /**
89          * Replaces emojis in the body
90          *
91          * @param array $emojis
92          * @param string $body
93          *
94          * @return string with replaced emojis
95          */
96         private static function replaceEmojis(int $uri_id, $body, array $emojis)
97         {
98                 $body = strtr($body,
99                         array_combine(
100                                 array_column($emojis, 'name'),
101                                 array_map(function ($emoji) {
102                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
103                                 }, $emojis)
104                         )
105                 );
106
107                 // We store the emoji here to be able to avoid storing it in the media
108                 foreach ($emojis as $emoji) {
109                         Post\Link::getByLink($uri_id, $emoji['href']);
110                 }
111                 return $body;
112         }
113
114         /**
115          * Store attached media files in the post-media table
116          *
117          * @param int $uriid
118          * @param array $attachment
119          * @return void
120          */
121         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
122         {
123                 if (empty($attachment['url'])) {
124                         return;
125                 }
126
127                 $data = ['uri-id' => $uriid];
128                 $data['type'] = Post\Media::UNKNOWN;
129                 $data['url'] = $attachment['url'];
130                 $data['mimetype'] = $attachment['mediaType'] ?? null;
131                 $data['height'] = $attachment['height'] ?? null;
132                 $data['width'] = $attachment['width'] ?? null;
133                 $data['size'] = $attachment['size'] ?? null;
134                 $data['preview'] = $attachment['image'] ?? null;
135                 $data['description'] = $attachment['name'] ?? null;
136
137                 Post\Media::insert($data);
138         }
139
140         /**
141          * Stire attachment data
142          *
143          * @param array   $activity
144          * @param array   $item
145          */
146         private static function storeAttachments($activity, $item)
147         {
148                 if (empty($activity['attachments'])) {
149                         return;
150                 }
151
152                 foreach ($activity['attachments'] as $attach) {
153                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
154                 }
155         }
156
157         /**
158          * Store attachment data
159          *
160          * @param array   $activity
161          * @param array   $item
162          */
163         private static function storeQuestion($activity, $item)
164         {
165                 if (empty($activity['question'])) {
166                         return;
167                 }
168                 $question = ['multiple' => $activity['question']['multiple']];
169
170                 if (!empty($activity['question']['voters'])) {
171                         $question['voters'] = $activity['question']['voters'];
172                 }
173
174                 if (!empty($activity['question']['end-time'])) {
175                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
176                 }
177
178                 Post\Question::update($item['uri-id'], $question);
179
180                 foreach ($activity['question']['options'] as $key => $option) {
181                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
182                         Post\QuestionOption::update($item['uri-id'], $key, $option);
183                 }
184
185                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
186         }
187
188         /**
189          * Updates a message
190          *
191          * @param array $activity Activity array
192          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
193          */
194         public static function updateItem($activity)
195         {
196                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
197                 if (!DBA::isResult($item)) {
198                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
199                         $item = self::createItem($activity);
200                         if (empty($item)) {
201                                 return;
202                         }
203
204                         self::postItem($activity, $item);
205                         return;
206                 }
207
208                 $item['changed'] = DateTimeFormat::utcNow();
209                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
210
211                 $item = self::processContent($activity, $item);
212
213                 self::storeAttachments($activity, $item);
214                 self::storeQuestion($activity, $item);
215
216                 if (empty($item)) {
217                         return;
218                 }
219
220                 Post\History::add($item['uri-id'], $item);
221                 Item::update($item, ['uri' => $activity['id']]);
222
223                 if ($activity['object_type'] == 'as:Event') {
224                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
225                         while ($post = DBA::fetch($posts)) {
226                                 self::updateEvent($post['event-id'], $activity);
227                         }
228                 }
229         }
230
231         /**
232          * Update an existing event
233          *
234          * @param int $event_id
235          * @param array $activity
236          */
237         private static function updateEvent(int $event_id, array $activity)
238         {
239                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
240
241                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
242                 $event['summary']  = HTML::toBBCode($activity['name']);
243                 $event['desc']     = HTML::toBBCode($activity['content']);
244                 if (!empty($activity['start-time'])) {
245                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
246                 }
247                 if (!empty($activity['end-time'])) {
248                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
249                 }
250                 $event['nofinish'] = empty($event['finish']);
251                 $event['location'] = $activity['location'];
252
253                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
254                 Event::store($event);
255         }
256
257         /**
258          * Prepares data for a message
259          *
260          * @param array $activity Activity array
261          * @return array Internal item
262          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
263          * @throws \ImagickException
264          */
265         public static function createItem($activity)
266         {
267                 $item = [];
268                 $item['verb'] = Activity::POST;
269                 $item['thr-parent'] = $activity['reply-to-id'];
270
271                 if ($activity['reply-to-id'] == $activity['id']) {
272                         $item['gravity'] = GRAVITY_PARENT;
273                         $item['object-type'] = Activity\ObjectType::NOTE;
274                 } else {
275                         $item['gravity'] = GRAVITY_COMMENT;
276                         $item['object-type'] = Activity\ObjectType::COMMENT;
277                 }
278
279                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
280                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
281                         self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
282                 }
283
284                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
285
286                 /// @todo What to do with $activity['context']?
287                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
288                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
289                         return [];
290                 }
291
292                 $item['network'] = Protocol::ACTIVITYPUB;
293                 $item['author-link'] = $activity['author'];
294                 $item['author-id'] = Contact::getIdForURL($activity['author']);
295                 $item['owner-link'] = $activity['actor'];
296                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
297
298                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
299                         $item['private'] = Item::UNLISTED;
300                 } elseif (in_array(0, $activity['receiver'])) {
301                         $item['private'] = Item::PUBLIC;
302                 } else {
303                         $item['private'] = Item::PRIVATE;
304                 }
305
306                 if (!empty($activity['raw'])) {
307                         $item['source'] = $activity['raw'];
308                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
309                         $item['conversation-href'] = $activity['context'] ?? '';
310                         $item['conversation-uri'] = $activity['conversation'] ?? '';
311
312                         if (isset($activity['push'])) {
313                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
314                         }
315                 }
316
317                 if (!empty($activity['from-relay'])) {
318                         $item['direction'] = Conversation::RELAY;
319                 }
320
321                 if ($activity['object_type'] == 'as:Article') {
322                         $item['post-type'] = Item::PT_ARTICLE;
323                 } elseif ($activity['object_type'] == 'as:Audio') {
324                         $item['post-type'] = Item::PT_AUDIO;
325                 } elseif ($activity['object_type'] == 'as:Document') {
326                         $item['post-type'] = Item::PT_DOCUMENT;
327                 } elseif ($activity['object_type'] == 'as:Event') {
328                         $item['post-type'] = Item::PT_EVENT;
329                 } elseif ($activity['object_type'] == 'as:Image') {
330                         $item['post-type'] = Item::PT_IMAGE;
331                 } elseif ($activity['object_type'] == 'as:Page') {
332                         $item['post-type'] = Item::PT_PAGE;
333                 } elseif ($activity['object_type'] == 'as:Question') {
334                         $item['post-type'] = Item::PT_POLL;
335                 } elseif ($activity['object_type'] == 'as:Video') {
336                         $item['post-type'] = Item::PT_VIDEO;
337                 } else {
338                         $item['post-type'] = Item::PT_NOTE;
339                 }
340
341                 $item['isForum'] = false;
342
343                 if (!empty($activity['thread-completion'])) {
344                         if ($activity['thread-completion'] != $item['owner-id']) {
345                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
346                                 $item['causer-link'] = $actor['url'];
347                                 $item['causer-id'] = $activity['thread-completion'];
348                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
349                         } else {
350                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
351                                 $item['causer-link'] = $item['owner-link'];
352                                 $item['causer-id']   = $item['owner-id'];
353                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
354                         }
355
356                         $item['owner-link'] = $item['author-link'];
357                         $item['owner-id'] = $item['author-id'];
358                 } else {
359                         $actor = APContact::getByURL($item['owner-link'], false);
360                         $item['isForum'] = ($actor['type'] == 'Group');
361                 }
362
363                 $item['uri'] = $activity['id'];
364
365                 if (empty($activity['published']) || empty($activity['updated'])) {
366                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
367                 }
368
369                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
370                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
371                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
372                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
373
374                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
375                 if (empty($item['uri-id'])) {
376                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
377                         return [];
378                 }
379
380                 $item = self::processContent($activity, $item);
381                 if (empty($item)) {
382                         Logger::info('Message was not processed');
383                         return [];
384                 }
385
386                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
387
388                 self::storeAttachments($activity, $item);
389                 self::storeQuestion($activity, $item);
390
391                 // We received the post via AP, so we set the protocol of the server to AP
392                 $contact = Contact::getById($item['author-id'], ['gsid']);
393                 if (!empty($contact['gsid'])) {
394                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
395                 }
396
397                 if ($item['author-id'] != $item['owner-id']) {
398                         $contact = Contact::getById($item['owner-id'], ['gsid']);
399                         if (!empty($contact['gsid'])) {
400                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
401                         }
402                 }
403
404                 return $item;
405         }
406
407         /**
408          * Delete items
409          *
410          * @param array $activity
411          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
412          * @throws \ImagickException
413          */
414         public static function deleteItem($activity)
415         {
416                 $owner = Contact::getIdForURL($activity['actor']);
417
418                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
419                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
420         }
421
422         /**
423          * Prepare the item array for an activity
424          *
425          * @param array $activity Activity array
426          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
427          * @throws \ImagickException
428          */
429         public static function addTag($activity)
430         {
431                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
432                         return;
433                 }
434
435                 foreach ($activity['receiver'] as $receiver) {
436                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
437                         if (!DBA::isResult($item)) {
438                                 // We don't fetch missing content for this purpose
439                                 continue;
440                         }
441
442                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
443                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
444                                 continue;
445                         }
446
447                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
448                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
449                 }
450         }
451
452         /**
453          * Prepare the item array for an activity
454          *
455          * @param array  $activity Activity array
456          * @param string $verb     Activity verb
457          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
458          * @throws \ImagickException
459          */
460         public static function createActivity($activity, $verb)
461         {
462                 $item = self::createItem($activity);
463                 if (empty($item)) {
464                         return;
465                 }
466
467                 $item['verb'] = $verb;
468                 $item['thr-parent'] = $activity['object_id'];
469                 $item['gravity'] = GRAVITY_ACTIVITY;
470                 unset($item['post-type']);
471                 $item['object-type'] = Activity\ObjectType::NOTE;
472
473                 if (!empty($activity['content'])) {
474                         $item['body'] = HTML::toBBCode($activity['content']);
475                 }
476
477                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
478
479                 self::postItem($activity, $item);
480         }
481
482         /**
483          * Fetch the Uri-Id of a post for the "featured" collection
484          *
485          * @param array $activity
486          * @return null|int
487          */
488         private static function getUriIdForFeaturedCollection(array $activity)
489         {
490                 $actor = APContact::getByURL($activity['actor']);
491                 if (empty($actor)) {
492                         return null;
493                 }
494
495                 // Refetch the account when the "featured" collection is missing.
496                 // This can be removed in a future version (end of 2022 should be good).
497                 if (empty($actor['featured'])) {
498                         $actor = APContact::getByURL($activity['actor'], true);
499                         if (empty($actor)) {
500                                 return null;
501                         }
502                 }
503
504                 if ($activity['target_id'] != $actor['featured']) {
505                         return null;
506                 }
507
508                 $id = Contact::getIdForURL($activity['actor']);
509                 if (empty($id)) {
510                         return null;
511                 }
512
513                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id'], 'author-id' => $id]);
514                 if (!empty($parent['uri-id'])) {
515                         return $parent['uri-id'];
516                 }
517
518                 return null;
519         }
520
521         /**
522          * Add a post to the "Featured" collection
523          *
524          * @param array $activity
525          */
526         public static function addToFeaturedCollection(array $activity)
527         {
528                 $uriid = self::getUriIdForFeaturedCollection($activity);
529                 if (empty($uriid)) {
530                         return;
531                 }
532
533                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
534
535                 Post\Collection::add($uriid, Post\Collection::FEATURED);
536         }
537
538         /**
539          * Remove a post to the "Featured" collection
540          *
541          * @param array $activity
542          */
543         public static function removeFromFeaturedCollection(array $activity)
544         {
545                 $uriid = self::getUriIdForFeaturedCollection($activity);
546                 if (empty($uriid)) {
547                         return;
548                 }
549
550                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
551
552                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
553         }
554
555         /**
556          * Create an event
557          *
558          * @param array $activity Activity array
559          * @param array $item
560          *
561          * @return int event id
562          * @throws \Exception
563          */
564         public static function createEvent($activity, $item)
565         {
566                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
567                 $event['desc']      = HTML::toBBCode($activity['content']);
568                 if (!empty($activity['start-time'])) {
569                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
570                 }
571                 if (!empty($activity['end-time'])) {
572                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
573                 }
574                 $event['nofinish']  = empty($event['finish']);
575                 $event['location']  = $activity['location'];
576                 $event['cid']       = $item['contact-id'];
577                 $event['uid']       = $item['uid'];
578                 $event['uri']       = $item['uri'];
579                 $event['edited']    = $item['edited'];
580                 $event['private']   = $item['private'];
581                 $event['guid']      = $item['guid'];
582                 $event['plink']     = $item['plink'];
583                 $event['network']   = $item['network'];
584                 $event['protocol']  = $item['protocol'];
585                 $event['direction'] = $item['direction'];
586                 $event['source']    = $item['source'];
587
588                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
589                 if (DBA::isResult($ev)) {
590                         $event['id'] = $ev['id'];
591                 }
592
593                 $event_id = Event::store($event);
594
595                 Logger::info('Event was stored', ['id' => $event_id]);
596
597                 return $event_id;
598         }
599
600         /**
601          * Process the content
602          *
603          * @param array $activity Activity array
604          * @param array $item
605          * @return array|bool Returns the item array or false if there was an unexpected occurrence
606          * @throws \Exception
607          */
608         private static function processContent($activity, $item)
609         {
610                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
611                         $item['title'] = Markdown::toBBCode($activity['name']);
612                         $content = Markdown::toBBCode($activity['content']);
613                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
614                         $item['title'] = $activity['name'];
615                         $content = $activity['content'];
616                 } else {
617                         // By default assume "text/html"
618                         $item['title'] = HTML::toBBCode($activity['name']);
619                         $content = HTML::toBBCode($activity['content']);
620                 }
621
622                 if (!empty($activity['languages'])) {
623                         $item['language'] = self::processLanguages($activity['languages']);
624                 }
625
626                 if (!empty($activity['emojis'])) {
627                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
628                 }
629
630                 $content = self::addMentionLinks($content, $activity['tags']);
631
632                 if (!empty($activity['source'])) {
633                         $item['body'] = $activity['source'];
634                         $item['raw-body'] = $content;
635                         $item['body'] = Item::improveSharedDataInBody($item);
636                 } else {
637                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
638                                 $item_private = !in_array(0, $activity['item_receiver']);
639                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
640                                 if (!DBA::isResult($parent)) {
641                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
642                                         return false;
643                                 }
644                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
645                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
646                                         return false;
647                                 }
648
649                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
650                         }
651                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
652                         $item['raw-body'] = $item['body'] = $content;
653                 }
654
655                 self::storeFromBody($item);
656                 self::storeTags($item['uri-id'], $activity['tags']);
657
658                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
659
660                 $item['location'] = $activity['location'];
661
662                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
663                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
664                 }
665
666                 $item['app'] = $activity['generator'];
667
668                 return $item;
669         }
670
671         /**
672          * Store hashtags and mentions
673          *
674          * @param array $item
675          */
676         private static function storeFromBody(array $item)
677         {
678                 // Make sure to delete all existing tags (can happen when called via the update functionality)
679                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
680
681                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
682         }
683
684         /**
685          * Generate a GUID out of an URL of an ActivityPub post.
686          *
687          * @param string $url message URL
688          * @return string with GUID
689          */
690         private static function getGUIDByURL(string $url)
691         {
692                 $parsed = parse_url($url);
693
694                 $host_hash = hash('crc32', $parsed['host']);
695
696                 unset($parsed["scheme"]);
697                 unset($parsed["host"]);
698
699                 $path = implode("/", $parsed);
700
701                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
702         }
703
704         /**
705          * Checks if an incoming message is wanted
706          *
707          * @param array $activity
708          * @param array $item
709          * @return boolean Is the message wanted?
710          */
711         private static function isSolicitedMessage(array $activity, array $item)
712         {
713                 // The checks are split to improve the support when searching why a message was accepted.
714                 if (count($activity['receiver']) != 1) {
715                         // The message has more than one receiver, so it is wanted.
716                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
717                         return true;
718                 }
719
720                 if ($item['private'] == Item::PRIVATE) {
721                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
722                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
723                         return true;
724                 }
725
726                 if (!empty($activity['from-relay'])) {
727                         // We check relay posts at another place. When it arrived here, the message is already checked.
728                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
729                         return true;
730                 }
731
732                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
733                         // Manual completions and completions caused by reshares are allowed without any further checks.
734                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
735                         return true;
736                 }
737
738                 if ($item['gravity'] != GRAVITY_PARENT) {
739                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
740                         // This can possibly be improved in the future.
741                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
742                         return true;
743                 }
744
745                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
746                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
747                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
748                         return true;
749                 } else {
750                         return false;
751                 }
752         }
753
754         /**
755          * Creates an item post
756          *
757          * @param array $activity Activity data
758          * @param array $item     item array
759          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
760          * @throws \ImagickException
761          */
762         public static function postItem(array $activity, array $item)
763         {
764                 if (empty($item)) {
765                         return;
766                 }
767
768                 $stored = false;
769                 ksort($activity['receiver']);
770
771                 if (!self::isSolicitedMessage($activity, $item)) {
772                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
773                         return;
774                 }
775
776                 foreach ($activity['receiver'] as $receiver) {
777                         if ($receiver == -1) {
778                                 continue;
779                         }
780
781                         $item['uid'] = $receiver;
782
783                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
784                         switch($type) {
785                                 case Receiver::TARGET_TO:
786                                         $item['post-reason'] = Item::PR_TO;
787                                         break;
788                                 case Receiver::TARGET_CC:
789                                         $item['post-reason'] = Item::PR_CC;
790                                         break;
791                                 case Receiver::TARGET_BTO:
792                                         $item['post-reason'] = Item::PR_BTO;
793                                         break;
794                                 case Receiver::TARGET_BCC:
795                                         $item['post-reason'] = Item::PR_BCC;
796                                         break;
797                                 case Receiver::TARGET_FOLLOWER:
798                                         $item['post-reason'] = Item::PR_FOLLOWER;
799                                         break;
800                                 case Receiver::TARGET_ANSWER:
801                                         $item['post-reason'] = Item::PR_COMMENT;
802                                         break;
803                                 case Receiver::TARGET_GLOBAL:
804                                         $item['post-reason'] = Item::PR_GLOBAL;
805                                         break;
806                                 default:
807                                         $item['post-reason'] = Item::PR_NONE;
808                         }
809
810                         if (!empty($activity['from-relay'])) {
811                                 $item['post-reason'] = Item::PR_RELAY;
812                         } elseif (!empty($activity['thread-completion'])) {
813                                 $item['post-reason'] = Item::PR_FETCHED;
814                         }
815
816                         if ($item['isForum'] ?? false) {
817                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
818                         } else {
819                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
820                         }
821
822                         if (($receiver != 0) && empty($item['contact-id'])) {
823                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
824                         }
825
826                         if (!empty($activity['directmessage'])) {
827                                 self::postMail($activity, $item);
828                                 continue;
829                         }
830
831                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
832                                 if ($item['post-reason'] == Item::PR_BCC) {
833                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
834                                         continue;
835                                 }
836
837                                 if (
838                                         !empty($activity['thread-children-type'])
839                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
840                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
841                                 ) {
842                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
843                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
844                                         continue;
845                                 }
846                         }
847
848                         $is_forum = false;
849
850                         if ($receiver != 0) {
851                                 $user = User::getById($receiver, ['account-type']);
852                                 if (!empty($user['account-type'])) {
853                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
854                                 }
855                         }
856
857                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
858                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
859
860                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
861                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
862                                 }
863
864                                 if ($skip) {
865                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
866                                         continue;
867                                 }
868
869                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
870                         }
871
872                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
873                                 $event_id = self::createEvent($activity, $item);
874
875                                 $item = Event::getItemArrayForImportedId($event_id, $item);
876                         }
877
878                         $item_id = Item::insert($item);
879                         if ($item_id) {
880                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
881                         } else {
882                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
883                         }
884
885                         if ($item['uid'] == 0) {
886                                 $stored = $item_id;
887                         }
888                 }
889
890                 // Store send a follow request for every reshare - but only when the item had been stored
891                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
892                         $author = APContact::getByURL($item['owner-link'], false);
893                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
894                         if ($author['type'] != 'Group') {
895                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
896                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
897                         }
898                 }
899         }
900
901         /**
902          * Store tags and mentions into the tag table
903          *
904          * @param integer $uriid
905          * @param array $tags
906          */
907         private static function storeTags(int $uriid, array $tags = null)
908         {
909                 foreach ($tags as $tag) {
910                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
911                                 continue;
912                         }
913
914                         $hash = substr($tag['name'], 0, 1);
915
916                         if ($tag['type'] == 'Mention') {
917                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
918                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
919                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
920                                         $tag['name'] = substr($tag['name'], 1);
921                                 }
922                                 $type = Tag::IMPLICIT_MENTION;
923
924                                 if (!empty($tag['href'])) {
925                                         $apcontact = APContact::getByURL($tag['href']);
926                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
927                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
928                                         }
929                                 }
930                         } elseif ($tag['type'] == 'Hashtag') {
931                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
932                                         $tag['name'] = substr($tag['name'], 1);
933                                 }
934                                 $type = Tag::HASHTAG;
935                         }
936
937                         if (empty($tag['name'])) {
938                                 continue;
939                         }
940
941                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
942                 }
943         }
944
945         public static function storeReceivers(int $uriid, array $receivers)
946         {
947                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
948                         if (!empty($receivers[$element])) {
949                                 foreach ($receivers[$element] as $receiver) {
950                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
951                                                 $name = Receiver::PUBLIC_COLLECTION;
952                                         } else {
953                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
954                                         }
955
956                                         $target = Tag::getTargetType($receiver);
957                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
958                                         Tag::store($uriid, $type, $name, $receiver, $target);
959                                 }
960                         }
961                 }
962         }
963
964         /**
965          * Creates an mail post
966          *
967          * @param array $activity Activity data
968          * @param array $item     item array
969          * @return int|bool New mail table row id or false on error
970          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
971          */
972         private static function postMail($activity, $item)
973         {
974                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
975                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
976                         return false;
977                 }
978
979                 Logger::info('Direct Message', $item);
980
981                 $msg = [];
982                 $msg['uid'] = $item['uid'];
983
984                 $msg['contact-id'] = $item['contact-id'];
985
986                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
987                 $msg['from-name'] = $contact['name'];
988                 $msg['from-url'] = $contact['url'];
989                 $msg['from-photo'] = $contact['photo'];
990
991                 $msg['uri'] = $item['uri'];
992                 $msg['created'] = $item['created'];
993
994                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
995                 if (DBA::isResult($parent)) {
996                         $msg['parent-uri'] = $parent['parent-uri'];
997                         $msg['title'] = $parent['title'];
998                 } else {
999                         $msg['parent-uri'] = $item['thr-parent'];
1000
1001                         if (!empty($item['title'])) {
1002                                 $msg['title'] = $item['title'];
1003                         } elseif (!empty($item['content-warning'])) {
1004                                 $msg['title'] = $item['content-warning'];
1005                         } else {
1006                                 // Trying to generate a title out of the body
1007                                 $title = $item['body'];
1008
1009                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1010                                         $title = $matches[3];
1011                                 }
1012
1013                                 $title = trim(BBCode::toPlaintext($title));
1014
1015                                 if (strlen($title) > 20) {
1016                                         $title = substr($title, 0, 20) . '...';
1017                                 }
1018
1019                                 $msg['title'] = $title;
1020                         }
1021                 }
1022                 $msg['body'] = $item['body'];
1023
1024                 return Mail::insert($msg);
1025         }
1026
1027         /**
1028          * Fetch featured posts from a contact with the given url
1029          *
1030          * @param string $url
1031          * @return void
1032          */
1033         public static function fetchFeaturedPosts(string $url)
1034         {
1035                 Logger::info('Fetch featured posts', ['contact' => $url]);
1036
1037                 $apcontact = APContact::getByURL($url);
1038                 if (empty($apcontact['featured'])) {
1039                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1040                         return;
1041                 }
1042
1043                 $pcid = Contact::getIdForURL($url, 0, false);
1044                 if (empty($pcid)) {
1045                         Logger::info('Contact not found', ['contact' => $url]);
1046                         return;
1047                 }
1048
1049                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1050                 if (!empty($posts)) {
1051                         $old_featured = array_column($posts, 'uri-id');
1052                 } else {
1053                         $old_featured = [];
1054                 }
1055
1056                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1057                 if (empty($featured)) {
1058                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1059
1060                         foreach ($old_featured as $uri_id) {
1061                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1062                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1063                         }
1064                         return;
1065                 }
1066
1067                 $new = 0;
1068                 $old = 0;
1069
1070                 foreach ($featured as $post) {
1071                         if (empty($post['id'])) {
1072                                 continue;
1073                         }
1074                         $id = Item::fetchByLink($post['id']);
1075                         if (!empty($id)) {
1076                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1077                                 if (!empty($item['uri-id'])) {
1078                                         if (!$item['featured']) {
1079                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1080                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1081                                                 $new++;
1082                                         } else {
1083                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1084                                                 $old++;
1085                                         }
1086
1087                                         $index = array_search($item['uri-id'], $old_featured);
1088                                         if (!($index === false)) {
1089                                                 unset($old_featured[$index]);
1090                                         }
1091                                 }
1092                         }
1093                 }
1094
1095                 foreach ($old_featured as $uri_id) {
1096                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1097                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1098                 }
1099
1100                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1101         }
1102
1103         /**
1104          * Fetches missing posts
1105          *
1106          * @param string $url         message URL
1107          * @param array  $child       activity array with the child of this message
1108          * @param string $relay_actor Relay actor
1109          * @param int    $completion  Completion mode, see Receiver::COMPLETION_*
1110          * @return string fetched message URL
1111          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1112          */
1113         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL)
1114         {
1115                 if (!empty($child['receiver'])) {
1116                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1117                 } else {
1118                         $uid = 0;
1119                 }
1120
1121                 $object = ActivityPub::fetchContent($url, $uid);
1122                 if (empty($object)) {
1123                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url]);
1124                         return '';
1125                 }
1126
1127                 if (empty($object['id'])) {
1128                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1129                         return '';
1130                 }
1131
1132                 if (!empty($object['actor'])) {
1133                         $object_actor = $object['actor'];
1134                 } elseif (!empty($object['attributedTo'])) {
1135                         $object_actor = $object['attributedTo'];
1136                         if (is_array($object_actor)) {
1137                                 $compacted = JsonLD::compact($object);
1138                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1139                         }
1140                 } else {
1141                         // Shouldn't happen
1142                         $object_actor = '';
1143                 }
1144
1145                 $signer = [$object_actor];
1146
1147                 if (!empty($child['author'])) {
1148                         $actor = $child['author'];
1149                         $signer[] = $actor;
1150                 } else {
1151                         $actor = $object_actor;
1152                 }
1153
1154                 if (!empty($object['published'])) {
1155                         $published = $object['published'];
1156                 } elseif (!empty($child['published'])) {
1157                         $published = $child['published'];
1158                 } else {
1159                         $published = DateTimeFormat::utcNow();
1160                 }
1161
1162                 $activity = [];
1163                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1164                 unset($object['@context']);
1165                 $activity['id'] = $object['id'];
1166                 $activity['to'] = $object['to'] ?? [];
1167                 $activity['cc'] = $object['cc'] ?? [];
1168                 $activity['actor'] = $actor;
1169                 $activity['object'] = $object;
1170                 $activity['published'] = $published;
1171                 $activity['type'] = 'Create';
1172
1173                 $ldactivity = JsonLD::compact($activity);
1174
1175                 if (!empty($relay_actor)) {
1176                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1177                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1178                 } elseif (!empty($child['thread-completion'])) {
1179                         $ldactivity['thread-completion'] = $child['thread-completion'];
1180                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1181                 } else {
1182                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1183                         $ldactivity['completion-mode']   = $completion;
1184                 }
1185
1186                 if (!empty($child['type'])) {
1187                         $ldactivity['thread-children-type'] = $child['type'];
1188                 }
1189
1190                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1191                         return '';
1192                 }
1193
1194                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1195
1196                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1197
1198                 return $activity['id'];
1199         }
1200
1201         /**
1202          * Test if incoming relay messages should be accepted
1203          *
1204          * @param array $activity activity array
1205          * @param string $id      object ID
1206          * @return boolean true if message is accepted
1207          */
1208         private static function acceptIncomingMessage(array $activity, string $id)
1209         {
1210                 if (empty($activity['as:object'])) {
1211                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1212                         return true;
1213                 }
1214
1215                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1216                 $uriid = ItemURI::getIdByURI($replyto);
1217                 if (Post::exists(['uri-id' => $uriid])) {
1218                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1219                         return true;
1220                 }
1221
1222                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1223                 $authorid = Contact::getIdForURL($attributed_to);
1224
1225                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
1226
1227                 $messageTags = [];
1228                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1229                 if (!empty($tags)) {
1230                         foreach ($tags as $tag) {
1231                                 if ($tag['type'] != 'Hashtag') {
1232                                         continue;
1233                                 }
1234                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1235                         }
1236                 }
1237
1238                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1239         }
1240
1241         /**
1242          * perform a "follow" request
1243          *
1244          * @param array $activity
1245          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1246          * @throws \ImagickException
1247          */
1248         public static function followUser($activity)
1249         {
1250                 $uid = User::getIdForURL($activity['object_id']);
1251                 if (empty($uid)) {
1252                         return;
1253                 }
1254
1255                 $owner = User::getOwnerDataById($uid);
1256                 if (empty($owner)) {
1257                         return;
1258                 }
1259
1260                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1261                 if (!empty($cid)) {
1262                         self::switchContact($cid);
1263                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1264                 }
1265
1266                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
1267                         'author-link' => $activity['actor']];
1268
1269                 // Ensure that the contact has got the right network type
1270                 self::switchContact($item['author-id']);
1271
1272                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1273                 if ($result === true) {
1274                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1275                 }
1276
1277                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1278                 if (empty($cid)) {
1279                         return;
1280                 }
1281
1282                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1283                         self::transmitPendingEvents($cid, $owner['uid']);
1284                 }
1285
1286                 if (empty($contact)) {
1287                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1288                 }
1289
1290                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1291         }
1292
1293         /**
1294          * Transmit pending events to the new follower
1295          *
1296          * @param integer $cid
1297          * @param integer $uid
1298          * @return void
1299          */
1300         private static function transmitPendingEvents(int $cid, int $uid)
1301         {
1302                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1303                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1304
1305                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1306                 while ($event = DBA::fetch($events)) {
1307                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1308                         if (empty($post)) {
1309                                 continue;
1310                         }
1311                         if (DI::config()->get('system', 'bulk_delivery')) {
1312                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1313                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1314                         } else {
1315                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1316                         }
1317                 }
1318         }
1319
1320         /**
1321          * Update the given profile
1322          *
1323          * @param array $activity
1324          * @throws \Exception
1325          */
1326         public static function updatePerson($activity)
1327         {
1328                 if (empty($activity['object_id'])) {
1329                         return;
1330                 }
1331
1332                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1333                 Contact::updateFromProbeByURL($activity['object_id']);
1334         }
1335
1336         /**
1337          * Delete the given profile
1338          *
1339          * @param array $activity
1340          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1341          */
1342         public static function deletePerson($activity)
1343         {
1344                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1345                         Logger::info('Empty object id or actor.');
1346                         return;
1347                 }
1348
1349                 if ($activity['object_id'] != $activity['actor']) {
1350                         Logger::info('Object id does not match actor.');
1351                         return;
1352                 }
1353
1354                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1355                 while ($contact = DBA::fetch($contacts)) {
1356                         Contact::remove($contact['id']);
1357                 }
1358                 DBA::close($contacts);
1359
1360                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1361         }
1362
1363         /**
1364          * Blocks the user by the contact
1365          *
1366          * @param array $activity
1367          * @throws \Exception
1368          */
1369         public static function blockAccount($activity)
1370         {
1371                 $cid = Contact::getIdForURL($activity['actor']);
1372                 if (empty($cid)) {
1373                         return;
1374                 }
1375
1376                 $uid = User::getIdForURL($activity['object_id']);
1377                 if (empty($uid)) {
1378                         return;
1379                 }
1380
1381                 Contact\User::setIsBlocked($cid, $uid, true);
1382
1383                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1384         }
1385
1386         /**
1387          * Unblocks the user by the contact
1388          *
1389          * @param array $activity
1390          * @throws \Exception
1391          */
1392         public static function unblockAccount($activity)
1393         {
1394                 $cid = Contact::getIdForURL($activity['actor']);
1395                 if (empty($cid)) {
1396                         return;
1397                 }
1398
1399                 $uid = User::getIdForURL($activity['object_object']);
1400                 if (empty($uid)) {
1401                         return;
1402                 }
1403
1404                 Contact\User::setIsBlocked($cid, $uid, false);
1405
1406                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1407         }
1408
1409         /**
1410          * Accept a follow request
1411          *
1412          * @param array $activity
1413          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1414          * @throws \ImagickException
1415          */
1416         public static function acceptFollowUser($activity)
1417         {
1418                 $uid = User::getIdForURL($activity['object_actor']);
1419                 if (empty($uid)) {
1420                         return;
1421                 }
1422
1423                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1424                 if (empty($cid)) {
1425                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1426                         return;
1427                 }
1428
1429                 self::switchContact($cid);
1430
1431                 $fields = ['pending' => false];
1432
1433                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1434                 if ($contact['rel'] == Contact::FOLLOWER) {
1435                         $fields['rel'] = Contact::FRIEND;
1436                 }
1437
1438                 $condition = ['id' => $cid];
1439                 Contact::update($fields, $condition);
1440                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1441         }
1442
1443         /**
1444          * Reject a follow request
1445          *
1446          * @param array $activity
1447          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1448          * @throws \ImagickException
1449          */
1450         public static function rejectFollowUser($activity)
1451         {
1452                 $uid = User::getIdForURL($activity['object_actor']);
1453                 if (empty($uid)) {
1454                         return;
1455                 }
1456
1457                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1458                 if (empty($cid)) {
1459                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1460                         return;
1461                 }
1462
1463                 self::switchContact($cid);
1464
1465                 $contact = Contact::getById($cid, ['rel']);
1466                 if ($contact['rel'] == Contact::SHARING) {
1467                         Contact::remove($cid);
1468                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1469                 } elseif ($contact['rel'] == Contact::FRIEND) {
1470                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1471                 } else {
1472                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1473                 }
1474         }
1475
1476         /**
1477          * Undo activity like "like" or "dislike"
1478          *
1479          * @param array $activity
1480          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1481          * @throws \ImagickException
1482          */
1483         public static function undoActivity($activity)
1484         {
1485                 if (empty($activity['object_id'])) {
1486                         return;
1487                 }
1488
1489                 if (empty($activity['object_actor'])) {
1490                         return;
1491                 }
1492
1493                 $author_id = Contact::getIdForURL($activity['object_actor']);
1494                 if (empty($author_id)) {
1495                         return;
1496                 }
1497
1498                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1499         }
1500
1501         /**
1502          * Activity to remove a follower
1503          *
1504          * @param array $activity
1505          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1506          * @throws \ImagickException
1507          */
1508         public static function undoFollowUser($activity)
1509         {
1510                 $uid = User::getIdForURL($activity['object_object']);
1511                 if (empty($uid)) {
1512                         return;
1513                 }
1514
1515                 $owner = User::getOwnerDataById($uid);
1516                 if (empty($owner)) {
1517                         return;
1518                 }
1519
1520                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1521                 if (empty($cid)) {
1522                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1523                         return;
1524                 }
1525
1526                 self::switchContact($cid);
1527
1528                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1529                 if (!DBA::isResult($contact)) {
1530                         return;
1531                 }
1532
1533                 Contact::removeFollower($contact);
1534                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1535         }
1536
1537         /**
1538          * Switches a contact to AP if needed
1539          *
1540          * @param integer $cid Contact ID
1541          * @throws \Exception
1542          */
1543         private static function switchContact($cid)
1544         {
1545                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1546                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1547                         return;
1548                 }
1549
1550                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1551                 Contact::updateFromProbe($cid);
1552         }
1553
1554         /**
1555          * Collects implicit mentions like:
1556          * - the author of the parent item
1557          * - all the mentioned conversants in the parent item
1558          *
1559          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1560          * @return array
1561          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1562          */
1563         private static function getImplicitMentionList(array $parent)
1564         {
1565                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1566
1567                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1568
1569                 $implicit_mentions = [];
1570                 if (empty($parent_author['url'])) {
1571                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1572                 } else {
1573                         $implicit_mentions[] = $parent_author['url'];
1574                         $implicit_mentions[] = $parent_author['nurl'];
1575                         $implicit_mentions[] = $parent_author['alias'];
1576                 }
1577
1578                 if (!empty($parent['alias'])) {
1579                         $implicit_mentions[] = $parent['alias'];
1580                 }
1581
1582                 foreach ($parent_terms as $term) {
1583                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1584                         if (!empty($contact['url'])) {
1585                                 $implicit_mentions[] = $contact['url'];
1586                                 $implicit_mentions[] = $contact['nurl'];
1587                                 $implicit_mentions[] = $contact['alias'];
1588                         }
1589                 }
1590
1591                 return $implicit_mentions;
1592         }
1593
1594         /**
1595          * Strips from the body prepended implicit mentions
1596          *
1597          * @param string $body
1598          * @param array $parent
1599          * @return string
1600          */
1601         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1602         {
1603                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1604                         return $body;
1605                 }
1606
1607                 $potential_mentions = self::getImplicitMentionList($parent);
1608
1609                 $kept_mentions = [];
1610
1611                 // Extract one prepended mention at a time from the body
1612                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1613                         if (!in_array($matches[2], $potential_mentions)) {
1614                                 $kept_mentions[] = $matches[1];
1615                         }
1616
1617                         $body = $matches[3];
1618                 }
1619
1620                 // Re-appending the kept mentions to the body after extraction
1621                 $kept_mentions[] = $body;
1622
1623                 return implode('', $kept_mentions);
1624         }
1625
1626         /**
1627          * Adds links to string mentions
1628          *
1629          * @param string $body
1630          * @param array  $tags
1631          * @return string
1632          */
1633         protected static function addMentionLinks(string $body, array $tags): string
1634         {
1635                 // This prevents links to be added again to Pleroma-style mention links
1636                 $body = self::normalizeMentionLinks($body);
1637
1638                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1639                         foreach ($tags as $tag) {
1640                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1641                                         continue;
1642                                 }
1643
1644                                 $hash = substr($tag['name'], 0, 1);
1645                                 $name = substr($tag['name'], 1);
1646                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1647                                         $hash = '';
1648                                         $name = $tag['name'];
1649                                 }
1650
1651                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1652                         }
1653
1654                         return $body;
1655                 });
1656
1657                 return $body;
1658         }
1659 }