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