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[friendica.git] / src / Protocol / ActivityPub / Transmitter.php
1 <?php
2 /**
3  * @copyright Copyright (C) 2020, Friendica
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\Feature;
25 use Friendica\Content\Text\BBCode;
26 use Friendica\Content\Text\Plaintext;
27 use Friendica\Core\Cache\Duration;
28 use Friendica\Core\Logger;
29 use Friendica\Core\Protocol;
30 use Friendica\Core\System;
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\GServer;
37 use Friendica\Model\Item;
38 use Friendica\Model\ItemURI;
39 use Friendica\Model\Profile;
40 use Friendica\Model\Photo;
41 use Friendica\Model\Post;
42 use Friendica\Model\Tag;
43 use Friendica\Model\User;
44 use Friendica\Protocol\Activity;
45 use Friendica\Protocol\ActivityPub;
46 use Friendica\Protocol\Relay;
47 use Friendica\Util\DateTimeFormat;
48 use Friendica\Util\HTTPSignature;
49 use Friendica\Util\JsonLD;
50 use Friendica\Util\LDSignature;
51 use Friendica\Util\Map;
52 use Friendica\Util\Network;
53 use Friendica\Util\XML;
54
55 /**
56  * ActivityPub Transmitter Protocol class
57  *
58  * To-Do:
59  * @todo Undo Announce
60  */
61 class Transmitter
62 {
63         /**
64          * Add relay servers to the list of inboxes
65          *
66          * @param array $inboxes
67          * @return array inboxes with added relay servers
68          */
69         public static function addRelayServerInboxes(array $inboxes = [])
70         {
71                 $contacts = DBA::select('apcontact', ['inbox'],
72                         ["`type` = ? AND `url` IN (SELECT `url` FROM `contact` WHERE `uid` = ? AND `rel` = ?)",
73                                 'Application', 0, Contact::FRIEND]);
74                 while ($contact = DBA::fetch($contacts)) {
75                         $inboxes[$contact['inbox']] = $contact['inbox'];
76                 }
77                 DBA::close($contacts);
78
79                 return $inboxes;
80         }
81
82         /**
83          * Add relay servers to the list of inboxes
84          *
85          * @param array $inboxes
86          * @return array inboxes with added relay servers
87          */
88         public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = [])
89         {
90                 $item = Post::selectFirst(['uid'], ['id' => $item_id]);
91                 if (empty($item)) {
92                         return $inboxes;
93                 }
94
95                 $relays = Relay::getList($item_id, [], [Protocol::ACTIVITYPUB]);
96                 if (empty($relays)) {
97                         return $inboxes;
98                 }
99
100                 foreach ($relays as $relay) {
101                         $contact = Contact::getByURLForUser($relay['url'], $item['uid'], false, ['id']);
102                         $inboxes[$relay['batch']][] = $contact['id'] ?? 0;
103                 }
104                 return $inboxes;
105         }
106
107         /**
108          * Subscribe to a relay
109          *
110          * @param string $url Subscribe actor url
111          * @return bool success
112          */
113         public static function sendRelayFollow(string $url)
114         {
115                 $contact = Contact::getByURL($url);
116                 if (empty($contact)) {
117                         return false;
118                 }
119
120                 $activity_id = ActivityPub\Transmitter::activityIDFromContact($contact['id']);
121                 $success = ActivityPub\Transmitter::sendActivity('Follow', $url, 0, $activity_id);
122                 if ($success) {
123                         DBA::update('contact', ['rel' => Contact::FRIEND], ['id' => $contact['id']]);
124                 }
125
126                 return $success;
127         }
128
129         /**
130          * Unsubscribe from a relay
131          *
132          * @param string $url   Subscribe actor url
133          * @param bool   $force Set the relay status as non follower even if unsubscribe hadn't worked
134          * @return bool success
135          */
136         public static function sendRelayUndoFollow(string $url, bool $force = false)
137         {
138                 $contact = Contact::getByURL($url);
139                 if (empty($contact)) {
140                         return false;
141                 }
142
143                 $success = self::sendContactUndo($url, $contact['id'], 0);
144                 if ($success || $force) {
145                         DBA::update('contact', ['rel' => Contact::NOTHING], ['id' => $contact['id']]);
146                 }
147
148                 return $success;
149         }
150         
151         /**
152          * Collects a list of contacts of the given owner
153          *
154          * @param array     $owner  Owner array
155          * @param int|array $rel    The relevant value(s) contact.rel should match
156          * @param string    $module The name of the relevant AP endpoint module (followers|following)
157          * @param integer   $page   Page number
158          *
159          * @return array of owners
160          * @throws \Exception
161          */
162         public static function getContacts($owner, $rel, $module, $page = null)
163         {
164                 $parameters = [
165                         'rel' => $rel,
166                         'uid' => $owner['uid'],
167                         'self' => false,
168                         'deleted' => false,
169                         'hidden' => false,
170                         'archive' => false,
171                         'pending' => false,
172                         'blocked' => false,
173                 ];
174                 $condition = DBA::buildCondition($parameters);
175
176                 $sql = "SELECT COUNT(*) as `count`
177                         FROM `contact`
178                         JOIN `apcontact` ON `apcontact`.`url` = `contact`.`url`
179                         " . $condition;
180
181                 $contacts = DBA::fetchFirst($sql, ...$parameters);
182
183                 $modulePath = '/' . $module . '/';
184
185                 $data = ['@context' => ActivityPub::CONTEXT];
186                 $data['id'] = DI::baseUrl() . $modulePath . $owner['nickname'];
187                 $data['type'] = 'OrderedCollection';
188                 $data['totalItems'] = $contacts['count'];
189
190                 // When we hide our friends we will only show the pure number but don't allow more.
191                 $profile = Profile::getByUID($owner['uid']);
192                 if (!empty($profile['hide-friends'])) {
193                         return $data;
194                 }
195
196                 if (empty($page)) {
197                         $data['first'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=1';
198                 } else {
199                         $data['type'] = 'OrderedCollectionPage';
200                         $list = [];
201
202                         $sql = "SELECT `contact`.`url`
203                                 FROM `contact`
204                                 JOIN `apcontact` ON `apcontact`.`url` = `contact`.`url`
205                                 " . $condition . "
206                                 LIMIT ?, ?";
207
208                         $parameters[] = ($page - 1) * 100;
209                         $parameters[] = 100;
210
211                         $contacts = DBA::p($sql, ...$parameters);
212                         while ($contact = DBA::fetch($contacts)) {
213                                 $list[] = $contact['url'];
214                         }
215                         DBA::close($contacts);
216
217                         if (!empty($list)) {
218                                 $data['next'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=' . ($page + 1);
219                         }
220
221                         $data['partOf'] = DI::baseUrl() . $modulePath . $owner['nickname'];
222
223                         $data['orderedItems'] = $list;
224                 }
225
226                 return $data;
227         }
228
229         /**
230          * Public posts for the given owner
231          *
232          * @param array   $owner     Owner array
233          * @param integer $page      Page number
234          * @param string  $requester URL of requesting account
235          *
236          * @return array of posts
237          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
238          * @throws \ImagickException
239          */
240         public static function getOutbox($owner, $page = null, $requester = '')
241         {
242                 $public_contact = Contact::getIdForURL($owner['url']);
243                 $condition = ['uid' => 0, 'contact-id' => $public_contact,
244                         'private' => [Item::PUBLIC, Item::UNLISTED]];
245
246                 if (!empty($requester)) {
247                         $requester_id = Contact::getIdForURL($requester, $owner['uid']);
248                         if (!empty($requester_id)) {
249                                 $permissionSets = DI::permissionSet()->selectByContactId($requester_id, $owner['uid']);
250                                 if (!empty($permissionSets)) {
251                                         $condition = ['uid' => $owner['uid'], 'origin' => true,
252                                                 'psid' => array_merge($permissionSets->column('id'),
253                                                         [DI::permissionSet()->getIdFromACL($owner['uid'], '', '', '', '')])];
254                                 }
255                         }
256                 }
257
258                 $condition = array_merge($condition,
259                         ['author-id' => $public_contact,
260                         'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT],
261                         'deleted' => false, 'visible' => true]);
262
263                 $count = Post::count($condition);
264
265                 $data = ['@context' => ActivityPub::CONTEXT];
266                 $data['id'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
267                 $data['type'] = 'OrderedCollection';
268                 $data['totalItems'] = $count;
269
270                 if (empty($page)) {
271                         $data['first'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
272                 } else {
273                         $data['type'] = 'OrderedCollectionPage';
274                         $list = [];
275
276                         $condition['parent-network'] = Protocol::NATIVE_SUPPORT;
277
278                         $items = Post::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
279                         while ($item = Post::fetch($items)) {
280                                 $activity = self::createActivityFromItem($item['id'], true);
281                                 $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
282
283                                 // Only list "Create" activity objects here, no reshares
284                                 if (!empty($activity['object']) && ($activity['type'] == 'Create')) {
285                                         $list[] = $activity['object'];
286                                 }
287                         }
288                         DBA::close($items);
289
290                         if (!empty($list)) {
291                                 $data['next'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
292                         }
293
294                         $data['partOf'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
295
296                         $data['orderedItems'] = $list;
297                 }
298
299                 return $data;
300         }
301
302         /**
303          * Return the service array containing information the used software and it's url
304          *
305          * @return array with service data
306          */
307         private static function getService()
308         {
309                 return ['type' => 'Service',
310                         'name' =>  FRIENDICA_PLATFORM . " '" . FRIENDICA_CODENAME . "' " . FRIENDICA_VERSION . '-' . DB_UPDATE_VERSION,
311                         'url' => DI::baseUrl()->get()];
312         }
313
314         /**
315          * Return the ActivityPub profile of the given user
316          *
317          * @param integer $uid User ID
318          * @return array with profile data
319          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
320          */
321         public static function getProfile($uid)
322         {
323                 if ($uid != 0) {
324                         $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
325                                 'account_removed' => false, 'verified' => true];
326                         $fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
327                         $user = DBA::selectFirst('user', $fields, $condition);
328                         if (!DBA::isResult($user)) {
329                                 return [];
330                         }
331
332                         $fields = ['locality', 'region', 'country-name'];
333                         $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid]);
334                         if (!DBA::isResult($profile)) {
335                                 return [];
336                         }
337
338                         $fields = ['name', 'url', 'location', 'about', 'avatar', 'photo'];
339                         $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
340                         if (!DBA::isResult($contact)) {
341                                 return [];
342                         }
343                 } else {
344                         $contact = User::getSystemAccount();
345                         $user = ['guid' => '', 'nickname' => $contact['nick'], 'pubkey' => $contact['pubkey'],
346                                 'account-type' => $contact['contact-type'], 'page-flags' => User::PAGE_FLAGS_NORMAL];
347                         $profile = ['locality' => '', 'region' => '', 'country-name' => ''];
348                 }
349
350                 $data = ['@context' => ActivityPub::CONTEXT];
351                 $data['id'] = $contact['url'];
352
353                 if (!empty($user['guid'])) {
354                         $data['diaspora:guid'] = $user['guid'];
355                 }
356
357                 $data['type'] = ActivityPub::ACCOUNT_TYPES[$user['account-type']];
358                 
359                 if ($uid != 0) {
360                         $data['following'] = DI::baseUrl() . '/following/' . $user['nickname'];
361                         $data['followers'] = DI::baseUrl() . '/followers/' . $user['nickname'];
362                         $data['inbox'] = DI::baseUrl() . '/inbox/' . $user['nickname'];
363                         $data['outbox'] = DI::baseUrl() . '/outbox/' . $user['nickname'];
364                 } else {
365                         $data['inbox'] = DI::baseUrl() . '/friendica/inbox';
366                 }
367
368                 $data['preferredUsername'] = $user['nickname'];
369                 $data['name'] = $contact['name'];
370
371                 if (!empty($profile['country-name'] . $profile['region'] . $profile['locality'])) {
372                         $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
373                                 'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
374                 }
375
376                 if (!empty($contact['about'])) {
377                         $data['summary'] = BBCode::convert($contact['about'], false);
378                 }
379
380                 $data['url'] = $contact['url'];
381                 $data['manuallyApprovesFollowers'] = in_array($user['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
382                 $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
383                         'owner' => $contact['url'],
384                         'publicKeyPem' => $user['pubkey']];
385                 $data['endpoints'] = ['sharedInbox' => DI::baseUrl() . '/inbox'];
386                 $data['icon'] = ['type' => 'Image',
387                         'url' => $contact['photo']];
388
389                 $data['generator'] = self::getService();
390
391                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
392                 return $data;
393         }
394
395         /**
396          * @param string $username
397          * @return array
398          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
399          */
400         public static function getDeletedUser($username)
401         {
402                 return [
403                         '@context' => ActivityPub::CONTEXT,
404                         'id' => DI::baseUrl() . '/profile/' . $username,
405                         'type' => 'Tombstone',
406                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
407                         'updated' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
408                         'deleted' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
409                 ];
410         }
411
412         /**
413          * Returns an array with permissions of a given item array
414          *
415          * @param array $item
416          *
417          * @return array with permissions
418          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
419          * @throws \ImagickException
420          */
421         private static function fetchPermissionBlockFromConversation($item)
422         {
423                 if (empty($item['thr-parent'])) {
424                         return [];
425                 }
426
427                 $condition = ['item-uri' => $item['thr-parent'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
428                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
429                 if (!DBA::isResult($conversation)) {
430                         return [];
431                 }
432
433                 $activity = json_decode($conversation['source'], true);
434
435                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
436                 if (!empty($actor)) {
437                         $permissions['to'][] = $actor;
438                         $profile = APContact::getByURL($actor);
439                 } else {
440                         $profile = [];
441                 }
442
443                 $item_profile = APContact::getByURL($item['author-link']);
444                 $exclude[] = $item['author-link'];
445
446                 if ($item['gravity'] == GRAVITY_PARENT) {
447                         $exclude[] = $item['owner-link'];
448                 }
449
450                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
451                         if (empty($activity[$element])) {
452                                 continue;
453                         }
454                         if (is_string($activity[$element])) {
455                                 $activity[$element] = [$activity[$element]];
456                         }
457
458                         foreach ($activity[$element] as $receiver) {
459                                 if (empty($receiver)) {
460                                         continue;
461                                 }
462
463                                 if (!empty($profile['followers']) && $receiver == $profile['followers'] && !empty($item_profile['followers'])) {
464                                         $permissions[$element][] = $item_profile['followers'];
465                                 } elseif (!in_array($receiver, $exclude)) {
466                                         $permissions[$element][] = $receiver;
467                                 }
468                         }
469                 }
470                 return $permissions;
471         }
472
473         /**
474          * Check if the given item id is from ActivityPub
475          *
476          * @param integer $item_id
477          * @return boolean "true" if the post is from ActivityPub
478          */
479         private static function isAPPost(int $item_id)
480         {
481                 if (empty($item_id)) {
482                         return false;
483                 }
484
485                 return Post::exists(['id' => $item_id, 'network' => Protocol::ACTIVITYPUB]);
486         }
487
488         /**
489          * Creates an array of permissions from an item thread
490          *
491          * @param array   $item       Item array
492          * @param boolean $blindcopy  addressing via "bcc" or "cc"?
493          * @param integer $last_id    Last item id for adding receivers
494          * @param boolean $forum_mode "true" means that we are sending content to a forum
495          *
496          * @return array with permission data
497          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
498          * @throws \ImagickException
499          */
500         private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0, $forum_mode = false)
501         {
502                 if ($last_id == 0) {
503                         $last_id = $item['id'];
504                 }
505
506                 $always_bcc = false;
507
508                 // Check if we should always deliver our stuff via BCC
509                 if (!empty($item['uid'])) {
510                         $profile = User::getOwnerDataById($item['uid']);
511                         if (!empty($profile)) {
512                                 $always_bcc = $profile['hide-friends'];
513                         }
514                 }
515
516                 if (DI::config()->get('system', 'ap_always_bcc')) {
517                         $always_bcc = true;
518                 }
519
520                 if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery') || self::isAPPost($last_id)) {
521                         // Will be activated in a later step
522                         $networks = Protocol::FEDERATED;
523                 } else {
524                         // For now only send to these contacts:
525                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
526                 }
527
528                 $data = ['to' => [], 'cc' => [], 'bcc' => []];
529
530                 if ($item['gravity'] == GRAVITY_PARENT) {
531                         $actor_profile = APContact::getByURL($item['owner-link']);
532                 } else {
533                         $actor_profile = APContact::getByURL($item['author-link']);
534                 }
535
536                 $terms = Tag::getByURIId($item['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
537
538                 if ($item['private'] != Item::PRIVATE) {
539                         // Directly mention the original author upon a quoted reshare.
540                         // Else just ensure that the original author receives the reshare.
541                         $announce = self::getAnnounceArray($item);
542                         if (!empty($announce['comment'])) {
543                                 $data['to'][] = $announce['actor']['url'];
544                         } elseif (!empty($announce)) {
545                                 $data['cc'][] = $announce['actor']['url'];
546                         }
547
548                         $data = array_merge($data, self::fetchPermissionBlockFromConversation($item));
549
550                         // Check if the item is completely public or unlisted
551                         if ($item['private'] == Item::PUBLIC) {
552                                 $data['to'][] = ActivityPub::PUBLIC_COLLECTION;
553                         } else {
554                                 $data['cc'][] = ActivityPub::PUBLIC_COLLECTION;
555                         }
556
557                         foreach ($terms as $term) {
558                                 $profile = APContact::getByURL($term['url'], false);
559                                 if (!empty($profile)) {
560                                         $data['to'][] = $profile['url'];
561                                 }
562                         }
563                 } else {
564                         $receiver_list = Item::enumeratePermissions($item, true);
565
566                         foreach ($terms as $term) {
567                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
568                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
569                                         $contact = DBA::selectFirst('contact', ['url', 'network', 'protocol', 'gsid'], ['id' => $cid, 'network' => Protocol::FEDERATED]);
570                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
571                                                 continue;
572                                         }
573
574                                         if (!empty($profile = APContact::getByURL($contact['url'], false))) {
575                                                 $data['to'][] = $profile['url'];
576                                         }
577                                 }
578                         }
579
580                         foreach ($receiver_list as $receiver) {
581                                 $contact = DBA::selectFirst('contact', ['url', 'hidden', 'network', 'protocol', 'gsid'], ['id' => $receiver, 'network' => Protocol::FEDERATED]);
582                                 if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
583                                         continue;
584                                 }
585
586                                 if (!empty($profile = APContact::getByURL($contact['url'], false))) {
587                                         if ($contact['hidden'] || $always_bcc) {
588                                                 $data['bcc'][] = $profile['url'];
589                                         } else {
590                                                 $data['cc'][] = $profile['url'];
591                                         }
592                                 }
593                         }
594                 }
595
596                 if (!empty($item['parent'])) {
597                         $parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']]);
598                         while ($parent = Post::fetch($parents)) {
599                                 if ($parent['gravity'] == GRAVITY_PARENT) {
600                                         $profile = APContact::getByURL($parent['owner-link'], false);
601                                         if (!empty($profile)) {
602                                                 if ($item['gravity'] != GRAVITY_PARENT) {
603                                                         // Comments to forums are directed to the forum
604                                                         // But comments to forums aren't directed to the followers collection
605                                                         // This rule is only valid when the actor isn't the forum.
606                                                         // The forum needs to transmit their content to their followers.
607                                                         if (($profile['type'] == 'Group') && ($profile['url'] != $actor_profile['url'])) {
608                                                                 $data['to'][] = $profile['url'];
609                                                         } else {
610                                                                 $data['cc'][] = $profile['url'];
611                                                                 if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])) {
612                                                                         $data['cc'][] = $actor_profile['followers'];
613                                                                 }
614                                                         }
615                                                 } else {
616                                                         // Public thread parent post always are directed to the followers
617                                                         if (($item['private'] != Item::PRIVATE) && !$forum_mode) {
618                                                                 $data['cc'][] = $actor_profile['followers'];
619                                                         }
620                                                 }
621                                         }
622                                 }
623
624                                 // Don't include data from future posts
625                                 if ($parent['id'] >= $last_id) {
626                                         continue;
627                                 }
628
629                                 $profile = APContact::getByURL($parent['author-link'], false);
630                                 if (!empty($profile)) {
631                                         if (($profile['type'] == 'Group') || ($parent['uri'] == $item['thr-parent'])) {
632                                                 $data['to'][] = $profile['url'];
633                                         } else {
634                                                 $data['cc'][] = $profile['url'];
635                                         }
636                                 }
637                         }
638                         DBA::close($parents);
639                 }
640
641                 $data['to'] = array_unique($data['to']);
642                 $data['cc'] = array_unique($data['cc']);
643                 $data['bcc'] = array_unique($data['bcc']);
644
645                 if (($key = array_search($item['author-link'], $data['to'])) !== false) {
646                         unset($data['to'][$key]);
647                 }
648
649                 if (($key = array_search($item['author-link'], $data['cc'])) !== false) {
650                         unset($data['cc'][$key]);
651                 }
652
653                 if (($key = array_search($item['author-link'], $data['bcc'])) !== false) {
654                         unset($data['bcc'][$key]);
655                 }
656
657                 foreach ($data['to'] as $to) {
658                         if (($key = array_search($to, $data['cc'])) !== false) {
659                                 unset($data['cc'][$key]);
660                         }
661
662                         if (($key = array_search($to, $data['bcc'])) !== false) {
663                                 unset($data['bcc'][$key]);
664                         }
665                 }
666
667                 foreach ($data['cc'] as $cc) {
668                         if (($key = array_search($cc, $data['bcc'])) !== false) {
669                                 unset($data['bcc'][$key]);
670                         }
671                 }
672
673                 $receivers = ['to' => array_values($data['to']), 'cc' => array_values($data['cc']), 'bcc' => array_values($data['bcc'])];
674
675                 if (!$blindcopy) {
676                         unset($receivers['bcc']);
677                 }
678
679                 return $receivers;
680         }
681
682         /**
683          * Check if an inbox is archived
684          *
685          * @param string $url Inbox url
686          *
687          * @return boolean "true" if inbox is archived
688          */
689         public static function archivedInbox($url)
690         {
691                 return DBA::exists('inbox-status', ['url' => $url, 'archive' => true]);
692         }
693
694         /**
695          * Check if a given contact should be delivered via AP
696          *
697          * @param array $contact 
698          * @param array $networks 
699          * @return bool 
700          * @throws Exception 
701          */
702         private static function isAPContact(array $contact, array $networks)
703         {
704                 if (in_array($contact['network'], $networks) || ($contact['protocol'] == Protocol::ACTIVITYPUB)) {
705                         return true;
706                 }
707
708                 return GServer::getProtocol($contact['gsid'] ?? 0) == Post\DeliveryData::ACTIVITYPUB;
709         }
710
711         /**
712          * Fetches a list of inboxes of followers of a given user
713          *
714          * @param integer $uid      User ID
715          * @param boolean $personal fetch personal inboxes
716          * @param boolean $all_ap   Retrieve all AP enabled inboxes
717          *
718          * @return array of follower inboxes
719          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
720          * @throws \ImagickException
721          */
722         public static function fetchTargetInboxesforUser($uid, $personal = false, bool $all_ap = false)
723         {
724                 $inboxes = [];
725
726                 $isforum = false;
727
728                 if (!empty($item['uid'])) {
729                         $profile = User::getOwnerDataById($item['uid']);
730                         if (!empty($profile)) {
731                                 $isforum = $profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY;
732                         }
733                 }
734
735                 if (DI::config()->get('debug', 'total_ap_delivery') || $all_ap) {
736                         // Will be activated in a later step
737                         $networks = Protocol::FEDERATED;
738                 } else {
739                         // For now only send to these contacts:
740                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
741                 }
742
743                 $condition = ['uid' => $uid, 'archive' => false, 'pending' => false, 'blocked' => false, 'network' => Protocol::FEDERATED];
744
745                 if (!empty($uid)) {
746                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
747                 }
748
749                 $contacts = DBA::select('contact', ['id', 'url', 'network', 'protocol', 'gsid'], $condition);
750                 while ($contact = DBA::fetch($contacts)) {
751                         if (Contact::isLocal($contact['url'])) {
752                                 continue;
753                         }
754
755                         if (!self::isAPContact($contact, $networks)) {
756                                 continue;
757                         }
758
759                         if ($isforum && ($contact['network'] == Protocol::DFRN)) {
760                                 continue;
761                         }
762
763                         if (Network::isUrlBlocked($contact['url'])) {
764                                 continue;
765                         }
766
767                         $profile = APContact::getByURL($contact['url'], false);
768                         if (!empty($profile)) {
769                                 if (empty($profile['sharedinbox']) || $personal) {
770                                         $target = $profile['inbox'];
771                                 } else {
772                                         $target = $profile['sharedinbox'];
773                                 }
774                                 if (!self::archivedInbox($target)) {
775                                         $inboxes[$target][] = $contact['id'];
776                                 }
777                         }
778                 }
779                 DBA::close($contacts);
780
781                 return $inboxes;
782         }
783
784         /**
785          * Fetches an array of inboxes for the given item and user
786          *
787          * @param array   $item       Item array
788          * @param integer $uid        User ID
789          * @param boolean $personal   fetch personal inboxes
790          * @param integer $last_id    Last item id for adding receivers
791          * @param boolean $forum_mode "true" means that we are sending content to a forum
792          * @return array with inboxes
793          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
794          * @throws \ImagickException
795          */
796         public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0, $forum_mode = false)
797         {
798                 $permissions = self::createPermissionBlockForItem($item, true, $last_id, $forum_mode);
799                 if (empty($permissions)) {
800                         return [];
801                 }
802
803                 $inboxes = [];
804
805                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
806                         $item_profile = APContact::getByURL($item['author-link'], false);
807                 } else {
808                         $item_profile = APContact::getByURL($item['owner-link'], false);
809                 }
810
811                 if (empty($item_profile)) {
812                         return [];
813                 }
814
815                 $profile_uid = User::getIdForURL($item_profile['url']);
816
817                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
818                         if (empty($permissions[$element])) {
819                                 continue;
820                         }
821
822                         $blindcopy = in_array($element, ['bto', 'bcc']);
823
824                         foreach ($permissions[$element] as $receiver) {
825                                 if (empty($receiver) || Network::isUrlBlocked($receiver)) {
826                                         continue;
827                                 }
828
829                                 if ($item_profile && ($receiver == $item_profile['followers']) && ($uid == $profile_uid)) {
830                                         $inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal, self::isAPPost($last_id)));
831                                 } else {
832                                         if (Contact::isLocal($receiver)) {
833                                                 continue;
834                                         }
835
836                                         $profile = APContact::getByURL($receiver, false);
837                                         if (!empty($profile)) {
838                                                 $contact = Contact::getByURLForUser($receiver, $uid, false, ['id']);
839
840                                                 if (empty($profile['sharedinbox']) || $personal || $blindcopy) {
841                                                         $target = $profile['inbox'];
842                                                 } else {
843                                                         $target = $profile['sharedinbox'];
844                                                 }
845                                                 if (!self::archivedInbox($target)) {
846                                                         $inboxes[$target][] = $contact['id'] ?? 0;
847                                                 }
848                                         }
849                                 }
850                         }
851                 }
852
853                 return $inboxes;
854         }
855
856         /**
857          * Creates an array in the structure of the item table for a given mail id
858          *
859          * @param integer $mail_id
860          *
861          * @return array
862          * @throws \Exception
863          */
864         public static function ItemArrayFromMail($mail_id)
865         {
866                 $mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
867                 if (!DBA::isResult($mail)) {
868                         return [];
869                 }
870
871                 $mail['uri-id'] = ItemURI::insert(['uri' => $mail['uri'], 'guid' => $mail['guid']]);
872
873                 $reply = DBA::selectFirst('mail', ['uri'], ['parent-uri' => $mail['parent-uri'], 'reply' => false]);
874
875                 // Making the post more compatible for Mastodon by:
876                 // - Making it a note and not an article (no title)
877                 // - Moving the title into the "summary" field that is used as a "content warning"
878                 $mail['body'] = '[abstract]' . $mail['title'] . "[/abstract]\n" . $mail['body'];
879                 $mail['title'] = '';
880
881                 $mail['author-link'] = $mail['owner-link'] = $mail['from-url'];
882                 $mail['allow_cid'] = '<'.$mail['contact-id'].'>';
883                 $mail['allow_gid'] = '';
884                 $mail['deny_cid'] = '';
885                 $mail['deny_gid'] = '';
886                 $mail['private'] = true;
887                 $mail['deleted'] = false;
888                 $mail['edited'] = $mail['created'];
889                 $mail['plink'] = $mail['uri'];
890                 $mail['thr-parent'] = $reply['uri'];
891                 $mail['gravity'] = ($mail['reply'] ? GRAVITY_COMMENT: GRAVITY_PARENT);
892
893                 $mail['event-type'] = '';
894
895                 $mail['parent'] = 0;
896
897                 return $mail;
898         }
899
900         /**
901          * Creates an activity array for a given mail id
902          *
903          * @param integer $mail_id
904          * @param boolean $object_mode Is the activity item is used inside another object?
905          *
906          * @return array of activity
907          * @throws \Exception
908          */
909         public static function createActivityFromMail($mail_id, $object_mode = false)
910         {
911                 $mail = self::ItemArrayFromMail($mail_id);
912                 if (empty($mail)) {
913                         return [];
914                 }
915                 $object = self::createNote($mail);
916
917                 if (!$object_mode) {
918                         $data = ['@context' => ActivityPub::CONTEXT];
919                 } else {
920                         $data = [];
921                 }
922
923                 $data['id'] = $mail['uri'] . '/Create';
924                 $data['type'] = 'Create';
925                 $data['actor'] = $mail['author-link'];
926                 $data['published'] = DateTimeFormat::utc($mail['created'] . '+00:00', DateTimeFormat::ATOM);
927                 $data['instrument'] = self::getService();
928                 $data = array_merge($data, self::createPermissionBlockForItem($mail, true));
929
930                 if (empty($data['to']) && !empty($data['cc'])) {
931                         $data['to'] = $data['cc'];
932                 }
933
934                 if (empty($data['to']) && !empty($data['bcc'])) {
935                         $data['to'] = $data['bcc'];
936                 }
937
938                 unset($data['cc']);
939                 unset($data['bcc']);
940
941                 $object['to'] = $data['to'];
942                 $object['tag'] = [['type' => 'Mention', 'href' => $object['to'][0], 'name' => '']];
943
944                 unset($object['cc']);
945                 unset($object['bcc']);
946
947                 $data['directMessage'] = true;
948
949                 $data['object'] = $object;
950
951                 $owner = User::getOwnerDataById($mail['uid']);
952
953                 if (!$object_mode && !empty($owner)) {
954                         return LDSignature::sign($data, $owner);
955                 } else {
956                         return $data;
957                 }
958         }
959
960         /**
961          * Returns the activity type of a given item
962          *
963          * @param array $item
964          *
965          * @return string with activity type
966          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
967          * @throws \ImagickException
968          */
969         private static function getTypeOfItem($item)
970         {
971                 $reshared = false;
972
973                 // Only check for a reshare, if it is a real reshare and no quoted reshare
974                 if (strpos($item['body'], "[share") === 0) {
975                         $announce = self::getAnnounceArray($item);
976                         $reshared = !empty($announce);
977                 }
978
979                 if ($reshared) {
980                         $type = 'Announce';
981                 } elseif ($item['verb'] == Activity::POST) {
982                         if ($item['created'] == $item['edited']) {
983                                 $type = 'Create';
984                         } else {
985                                 $type = 'Update';
986                         }
987                 } elseif ($item['verb'] == Activity::LIKE) {
988                         $type = 'Like';
989                 } elseif ($item['verb'] == Activity::DISLIKE) {
990                         $type = 'Dislike';
991                 } elseif ($item['verb'] == Activity::ATTEND) {
992                         $type = 'Accept';
993                 } elseif ($item['verb'] == Activity::ATTENDNO) {
994                         $type = 'Reject';
995                 } elseif ($item['verb'] == Activity::ATTENDMAYBE) {
996                         $type = 'TentativeAccept';
997                 } elseif ($item['verb'] == Activity::FOLLOW) {
998                         $type = 'Follow';
999                 } elseif ($item['verb'] == Activity::TAG) {
1000                         $type = 'Add';
1001                 } elseif ($item['verb'] == Activity::ANNOUNCE) {
1002                         $type = 'Announce';
1003                 } else {
1004                         $type = '';
1005                 }
1006
1007                 return $type;
1008         }
1009
1010         /**
1011          * Creates the activity or fetches it from the cache
1012          *
1013          * @param integer $item_id
1014          * @param boolean $force Force new cache entry
1015          *
1016          * @return array with the activity
1017          * @throws \Exception
1018          */
1019         public static function createCachedActivityFromItem($item_id, $force = false)
1020         {
1021                 $cachekey = 'APDelivery:createActivity:' . $item_id;
1022
1023                 if (!$force) {
1024                         $data = DI::cache()->get($cachekey);
1025                         if (!is_null($data)) {
1026                                 return $data;
1027                         }
1028                 }
1029
1030                 $data = self::createActivityFromItem($item_id);
1031
1032                 DI::cache()->set($cachekey, $data, Duration::QUARTER_HOUR);
1033                 return $data;
1034         }
1035
1036         /**
1037          * Creates an activity array for a given item id
1038          *
1039          * @param integer $item_id
1040          * @param boolean $object_mode Is the activity item is used inside another object?
1041          *
1042          * @return false|array
1043          * @throws \Exception
1044          */
1045         public static function createActivityFromItem(int $item_id, bool $object_mode = false)
1046         {
1047                 Logger::info('Fetching activity', ['item' => $item_id]);
1048                 $item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
1049                 if (!DBA::isResult($item)) {
1050                         return false;
1051                 }
1052
1053                 // In case of a forum post ensure to return the original post if author and forum are on the same machine
1054                 if (($item['gravity'] == GRAVITY_PARENT) && !empty($item['forum_mode'])) {
1055                         $author = Contact::getById($item['author-id'], ['nurl']);
1056                         if (!empty($author['nurl'])) {
1057                                 $self = Contact::selectFirst(['uid'], ['nurl' => $author['nurl'], 'self' => true]);
1058                                 if (!empty($self['uid'])) {
1059                                         $forum_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['uri-id' => $item['uri-id'], 'uid' => $self['uid']]);
1060                                         if (DBA::isResult($forum_item)) {
1061                                                 $item = $forum_item; 
1062                                         }
1063                                 }
1064                         }
1065                 }
1066
1067                 if (empty($item['uri-id'])) {
1068                         Logger::warning('Item without uri-id', ['item' => $item]);
1069                         return false;
1070                 }
1071
1072                 $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
1073                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
1074                 if (!$item['origin'] && DBA::isResult($conversation)) {
1075                         $data = json_decode($conversation['source'], true);
1076                         if (!empty($data['type'])) {
1077                                 if (in_array($data['type'], ['Create', 'Update'])) {
1078                                         if ($object_mode) {
1079                                                 unset($data['@context']);
1080                                                 unset($data['signature']);
1081                                         }
1082                                         Logger::info('Return stored conversation', ['item' => $item_id]);
1083                                         return $data;
1084                                 } elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
1085                                         if (!empty($data['@context'])) {
1086                                                 $context = $data['@context'];
1087                                                 unset($data['@context']);
1088                                         }
1089                                         unset($data['actor']);
1090                                         $object = $data;
1091                                 }
1092                         }
1093                 }
1094
1095                 $type = self::getTypeOfItem($item);
1096
1097                 if (!$object_mode) {
1098                         $data = ['@context' => $context ?? ActivityPub::CONTEXT];
1099
1100                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
1101                                 $type = 'Undo';
1102                         } elseif ($item['deleted']) {
1103                                 $type = 'Delete';
1104                         }
1105                 } else {
1106                         $data = [];
1107                 }
1108
1109                 if (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
1110                         $data['id'] = $item['uri'];
1111                 } else {
1112                         $data['id'] = $item['uri'] . '/' . $type;
1113                 }
1114
1115                 $data['type'] = $type;
1116
1117                 if (($type != 'Announce') || ($item['gravity'] != GRAVITY_PARENT)) {
1118                         $data['actor'] = $item['author-link'];
1119                 } else {
1120                         $data['actor'] = $item['owner-link'];
1121                 }
1122
1123                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1124
1125                 $data['instrument'] = self::getService();
1126
1127                 $data = array_merge($data, self::createPermissionBlockForItem($item, false));
1128
1129                 if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
1130                         $data['object'] = $object ?? self::createNote($item);
1131                 } elseif ($data['type'] == 'Add') {
1132                         $data = self::createAddTag($item, $data);
1133                 } elseif ($data['type'] == 'Announce') {
1134                         if ($item['verb'] == ACTIVITY::ANNOUNCE) {
1135                                 $data['object'] = $item['thr-parent'];
1136                         } else {
1137                                 $data = self::createAnnounce($item, $data);
1138                         }
1139                 } elseif ($data['type'] == 'Follow') {
1140                         $data['object'] = $item['parent-uri'];
1141                 } elseif ($data['type'] == 'Undo') {
1142                         $data['object'] = self::createActivityFromItem($item_id, true);
1143                 } else {
1144                         $data['diaspora:guid'] = $item['guid'];
1145                         if (!empty($item['signed_text'])) {
1146                                 $data['diaspora:like'] = $item['signed_text'];
1147                         }
1148                         $data['object'] = $item['thr-parent'];
1149                 }
1150
1151                 if (!empty($item['contact-uid'])) {
1152                         $uid = $item['contact-uid'];
1153                 } else {
1154                         $uid = $item['uid'];
1155                 }
1156
1157                 $owner = User::getOwnerDataById($uid);
1158
1159                 Logger::info('Fetched activity', ['item' => $item_id, 'uid' => $uid]);
1160
1161                 // We don't sign if we aren't the actor. This is important for relaying content especially for forums
1162                 if (!$object_mode && !empty($owner) && ($data['actor'] == $owner['url'])) {
1163                         return LDSignature::sign($data, $owner);
1164                 } else {
1165                         return $data;
1166                 }
1167
1168                 /// @todo Create "conversation" entry
1169         }
1170
1171         /**
1172          * Creates a location entry for a given item array
1173          *
1174          * @param array $item
1175          *
1176          * @return array with location array
1177          */
1178         private static function createLocation($item)
1179         {
1180                 $location = ['type' => 'Place'];
1181
1182                 if (!empty($item['location'])) {
1183                         $location['name'] = $item['location'];
1184                 }
1185
1186                 $coord = [];
1187
1188                 if (empty($item['coord'])) {
1189                         $coord = Map::getCoordinates($item['location']);
1190                 } else {
1191                         $coords = explode(' ', $item['coord']);
1192                         if (count($coords) == 2) {
1193                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
1194                         }
1195                 }
1196
1197                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
1198                         $location['latitude'] = $coord['lat'];
1199                         $location['longitude'] = $coord['lon'];
1200                 }
1201
1202                 return $location;
1203         }
1204
1205         /**
1206          * Returns a tag array for a given item array
1207          *
1208          * @param array $item
1209          *
1210          * @return array of tags
1211          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1212          */
1213         private static function createTagList($item)
1214         {
1215                 $tags = [];
1216
1217                 $terms = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG, Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1218                 foreach ($terms as $term) {
1219                         if ($term['type'] == Tag::HASHTAG) {
1220                                 $url = DI::baseUrl() . '/search?tag=' . urlencode($term['name']);
1221                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['name']];
1222                         } else {
1223                                 $contact = Contact::getByURL($term['url'], false, ['addr']);
1224                                 if (empty($contact)) {
1225                                         continue;
1226                                 }
1227                                 if (!empty($contact['addr'])) {
1228                                         $mention = '@' . $contact['addr'];
1229                                 } else {
1230                                         $mention = '@' . $term['url'];
1231                                 }
1232
1233                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
1234                         }
1235                 }
1236
1237                 $announce = self::getAnnounceArray($item);
1238                 // Mention the original author upon commented reshares
1239                 if (!empty($announce['comment'])) {
1240                         $tags[] = ['type' => 'Mention', 'href' => $announce['actor']['url'], 'name' => '@' . $announce['actor']['addr']];
1241                 }
1242
1243                 return $tags;
1244         }
1245
1246         /**
1247          * Adds attachment data to the JSON document
1248          *
1249          * @param array  $item Data of the item that is to be posted
1250          * @param string $type Object type
1251          *
1252          * @return array with attachment data
1253          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1254          */
1255         private static function createAttachmentList($item, $type)
1256         {
1257                 $attachments = [];
1258
1259                 // Currently deactivated, since it creates side effects on Mastodon and Pleroma.
1260                 // It will be reactivated, once this cleared.
1261                 /*
1262                 $attach_data = BBCode::getAttachmentData($item['body']);
1263                 if (!empty($attach_data['url'])) {
1264                         $attachment = ['type' => 'Page',
1265                                 'mediaType' => 'text/html',
1266                                 'url' => $attach_data['url']];
1267
1268                         if (!empty($attach_data['title'])) {
1269                                 $attachment['name'] = $attach_data['title'];
1270                         }
1271
1272                         if (!empty($attach_data['description'])) {
1273                                 $attachment['summary'] = $attach_data['description'];
1274                         }
1275
1276                         if (!empty($attach_data['image'])) {
1277                                 $imgdata = Images::getInfoFromURLCached($attach_data['image']);
1278                                 if ($imgdata) {
1279                                         $attachment['icon'] = ['type' => 'Image',
1280                                                 'mediaType' => $imgdata['mime'],
1281                                                 'width' => $imgdata[0],
1282                                                 'height' => $imgdata[1],
1283                                                 'url' => $attach_data['image']];
1284                                 }
1285                         }
1286
1287                         $attachments[] = $attachment;
1288                 }
1289                 */
1290                 foreach (Post\Media::getByURIId($item['uri-id'], [Post\Media::DOCUMENT, Post\Media::TORRENT, Post\Media::UNKNOWN]) as $attachment) {
1291                         $attachments[] = ['type' => 'Document',
1292                                 'mediaType' => $attachment['mimetype'],
1293                                 'url' => $attachment['url'],
1294                                 'name' => $attachment['description']];
1295                 }
1296
1297                 if ($type != 'Note') {
1298                         return $attachments;
1299                 }
1300
1301                 foreach (Post\Media::getByURIId($item['uri-id'], [Post\Media::AUDIO, Post\Media::IMAGE, Post\Media::VIDEO]) as $attachment) {
1302                         $attachments[] = ['type' => 'Document',
1303                                 'mediaType' => $attachment['mimetype'],
1304                                 'url' => $attachment['url'],
1305                                 'name' => $attachment['description']];
1306                 }
1307
1308                 return $attachments;
1309         }
1310
1311         /**
1312          * Callback function to replace a Friendica style mention in a mention that is used on AP
1313          *
1314          * @param array $match Matching values for the callback
1315          * @return string Replaced mention
1316          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1317          */
1318         private static function mentionCallback($match)
1319         {
1320                 if (empty($match[1])) {
1321                         return '';
1322                 }
1323
1324                 $data = Contact::getByURL($match[1], false, ['url', 'alias', 'nick']);
1325                 if (empty($data['nick'])) {
1326                         return $match[0];
1327                 }
1328
1329                 return '[url=' . ($data['alias'] ?: $data['url']) . ']@' . $data['nick'] . '[/url]';
1330         }
1331
1332         /**
1333          * Remove image elements since they are added as attachment
1334          *
1335          * @param string $body
1336          *
1337          * @return string with removed images
1338          */
1339         private static function removePictures($body)
1340         {
1341                 // Simplify image codes
1342                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
1343                 $body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
1344
1345                 // Now remove local links
1346                 $body = preg_replace_callback(
1347                         '/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi',
1348                         function ($match) {
1349                                 // We remove the link when it is a link to a local photo page
1350                                 if (Photo::isLocalPage($match[1])) {
1351                                         return '';
1352                                 }
1353                                 // otherwise we just return the link
1354                                 return '[url]' . $match[1] . '[/url]';
1355                         },
1356                         $body
1357                 );
1358
1359                 // Remove all pictures
1360                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '', $body);
1361
1362                 return $body;
1363         }
1364
1365         /**
1366          * Fetches the "context" value for a givem item array from the "conversation" table
1367          *
1368          * @param array $item
1369          *
1370          * @return string with context url
1371          * @throws \Exception
1372          */
1373         private static function fetchContextURLForItem($item)
1374         {
1375                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
1376                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
1377                         $context_uri = $conversation['conversation-href'];
1378                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
1379                         $context_uri = $conversation['conversation-uri'];
1380                 } else {
1381                         $context_uri = $item['parent-uri'] . '#context';
1382                 }
1383                 return $context_uri;
1384         }
1385
1386         /**
1387          * Returns if the post contains sensitive content ("nsfw")
1388          *
1389          * @param integer $uri_id
1390          *
1391          * @return boolean
1392          * @throws \Exception
1393          */
1394         private static function isSensitive($uri_id)
1395         {
1396                 return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw']);
1397         }
1398
1399         /**
1400          * Creates event data
1401          *
1402          * @param array $item
1403          *
1404          * @return array with the event data
1405          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1406          */
1407         public static function createEvent($item)
1408         {
1409                 $event = [];
1410                 $event['name'] = $item['event-summary'];
1411                 $event['content'] = BBCode::convert($item['event-desc'], false, BBCode::ACTIVITYPUB);
1412                 $event['startTime'] = DateTimeFormat::utc($item['event-start'] . '+00:00', DateTimeFormat::ATOM);
1413
1414                 if (!$item['event-nofinish']) {
1415                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'] . '+00:00', DateTimeFormat::ATOM);
1416                 }
1417
1418                 if (!empty($item['event-location'])) {
1419                         $item['location'] = $item['event-location'];
1420                         $event['location'] = self::createLocation($item);
1421                 }
1422
1423                 return $event;
1424         }
1425
1426         /**
1427          * Creates a note/article object array
1428          *
1429          * @param array $item
1430          *
1431          * @return array with the object data
1432          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1433          * @throws \ImagickException
1434          */
1435         public static function createNote($item)
1436         {
1437                 if (empty($item)) {
1438                         return [];
1439                 }
1440
1441                 if ($item['event-type'] == 'event') {
1442                         $type = 'Event';
1443                 } elseif (!empty($item['title'])) {
1444                         $type = 'Article';
1445                 } else {
1446                         $type = 'Note';
1447                 }
1448
1449                 if ($item['deleted']) {
1450                         $type = 'Tombstone';
1451                 }
1452
1453                 $data = [];
1454                 $data['id'] = $item['uri'];
1455                 $data['type'] = $type;
1456
1457                 if ($item['deleted']) {
1458                         return $data;
1459                 }
1460
1461                 $data['summary'] = BBCode::toPlaintext(BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB));
1462
1463                 if ($item['uri'] != $item['thr-parent']) {
1464                         $data['inReplyTo'] = $item['thr-parent'];
1465                 } else {
1466                         $data['inReplyTo'] = null;
1467                 }
1468
1469                 $data['diaspora:guid'] = $item['guid'];
1470                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1471
1472                 if ($item['created'] != $item['edited']) {
1473                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1474                 }
1475
1476                 $data['url'] = $item['plink'];
1477                 $data['attributedTo'] = $item['author-link'];
1478                 $data['sensitive'] = self::isSensitive($item['uri-id']);
1479                 $data['context'] = self::fetchContextURLForItem($item);
1480
1481                 if (!empty($item['title'])) {
1482                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1483                 }
1484
1485                 $permission_block = self::createPermissionBlockForItem($item, false);
1486
1487                 $body = $item['body'];
1488
1489                 if ($type == 'Note') {
1490                         $body = $item['raw-body'] ?? self::removePictures($body);
1491                 } elseif (($type == 'Article') && empty($data['summary'])) {
1492                         $data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($body), 1000));
1493                 }
1494
1495                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1496                         $body = self::prependMentions($body, $item['uri-id'], $item['author-link']);
1497                 }
1498
1499                 if ($type == 'Event') {
1500                         $data = array_merge($data, self::createEvent($item));
1501                 } else {
1502                         $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1503                         $body = preg_replace_callback($regexp, ['self', 'mentionCallback'], $body);
1504
1505                         $data['content'] = BBCode::convert($body, false, BBCode::ACTIVITYPUB);
1506                 }
1507
1508                 // The regular "content" field does contain a minimized HTML. This is done since systems like
1509                 // Mastodon has got problems with - for example - embedded pictures.
1510                 // The contentMap does contain the unmodified HTML.
1511                 $language = self::getLanguage($item);
1512                 if (!empty($language)) {
1513                         $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1514                         $richbody = preg_replace_callback($regexp, ['self', 'mentionCallback'], $item['body']);
1515                         $richbody = BBCode::removeAttachment($richbody);
1516
1517                         $data['contentMap'][$language] = BBCode::convert($richbody, false);
1518                 }
1519
1520                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1521
1522                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1523                         $data['diaspora:comment'] = $item['signed_text'];
1524                 }
1525
1526                 $data['attachment'] = self::createAttachmentList($item, $type);
1527                 $data['tag'] = self::createTagList($item);
1528
1529                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1530                         $data['location'] = self::createLocation($item);
1531                 }
1532
1533                 if (!empty($item['app'])) {
1534                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1535                 }
1536
1537                 $data = array_merge($data, $permission_block);
1538
1539                 return $data;
1540         }
1541
1542         /**
1543          * Fetches the language from the post, the user or the system.
1544          *
1545          * @param array $item
1546          *
1547          * @return string language string
1548          */
1549         private static function getLanguage(array $item)
1550         {
1551                 // Try to fetch the language from the post itself
1552                 if (!empty($item['language'])) {
1553                         $languages = array_keys(json_decode($item['language'], true));
1554                         if (!empty($languages[0])) {
1555                                 return $languages[0];
1556                         }
1557                 }
1558
1559                 // Otherwise use the user's language
1560                 if (!empty($item['uid'])) {
1561                         $user = DBA::selectFirst('user', ['language'], ['uid' => $item['uid']]);
1562                         if (!empty($user['language'])) {
1563                                 return $user['language'];
1564                         }
1565                 }
1566
1567                 // And finally just use the system language
1568                 return DI::config()->get('system', 'language');
1569         }
1570
1571         /**
1572          * Creates an an "add tag" entry
1573          *
1574          * @param array $item
1575          * @param array $data activity data
1576          *
1577          * @return array with activity data for adding tags
1578          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1579          * @throws \ImagickException
1580          */
1581         private static function createAddTag($item, $data)
1582         {
1583                 $object = XML::parseString($item['object']);
1584                 $target = XML::parseString($item["target"]);
1585
1586                 $data['diaspora:guid'] = $item['guid'];
1587                 $data['actor'] = $item['author-link'];
1588                 $data['target'] = (string)$target->id;
1589                 $data['summary'] = BBCode::toPlaintext($item['body']);
1590                 $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
1591
1592                 return $data;
1593         }
1594
1595         /**
1596          * Creates an announce object entry
1597          *
1598          * @param array $item
1599          * @param array $data activity data
1600          *
1601          * @return array with activity data
1602          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1603          * @throws \ImagickException
1604          */
1605         private static function createAnnounce($item, $data)
1606         {
1607                 $orig_body = $item['body'];
1608                 $announce = self::getAnnounceArray($item);
1609                 if (empty($announce)) {
1610                         $data['type'] = 'Create';
1611                         $data['object'] = self::createNote($item);
1612                         return $data;
1613                 }
1614
1615                 if (empty($announce['comment'])) {
1616                         // Pure announce, without a quote
1617                         $data['type'] = 'Announce';
1618                         $data['object'] = $announce['object']['uri'];
1619                         return $data;
1620                 }
1621
1622                 // Quote
1623                 $data['type'] = 'Create';
1624                 $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
1625                 $data['object'] = self::createNote($item);
1626
1627                 /// @todo Finally descide how to implement this in AP. This is a possible way:
1628                 $data['object']['attachment'][] = self::createNote($announce['object']);
1629
1630                 $data['object']['source']['content'] = $orig_body;
1631                 return $data;
1632         }
1633
1634         /**
1635          * Return announce related data if the item is an annunce
1636          *
1637          * @param array $item
1638          *
1639          * @return array
1640          */
1641         public static function getAnnounceArray($item)
1642         {
1643                 $reshared = Item::getShareArray($item);
1644                 if (empty($reshared['guid'])) {
1645                         return [];
1646                 }
1647
1648                 $reshared_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['guid' => $reshared['guid']]);
1649                 if (!DBA::isResult($reshared_item)) {
1650                         return [];
1651                 }
1652
1653                 if (!in_array($reshared_item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
1654                         return [];
1655                 }
1656
1657                 $profile = APContact::getByURL($reshared_item['author-link'], false);
1658                 if (empty($profile)) {
1659                         return [];
1660                 }
1661
1662                 return ['object' => $reshared_item, 'actor' => $profile, 'comment' => $reshared['comment']];
1663         }
1664
1665         /**
1666          * Checks if the provided item array is an announce
1667          *
1668          * @param array $item
1669          *
1670          * @return boolean
1671          */
1672         public static function isAnnounce($item)
1673         {
1674                 if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
1675                         return true;
1676                 }
1677
1678                 $announce = self::getAnnounceArray($item);
1679                 if (empty($announce)) {
1680                         return false;
1681                 }
1682
1683                 return empty($announce['comment']);
1684         }
1685
1686         /**
1687          * Creates an activity id for a given contact id
1688          *
1689          * @param integer $cid Contact ID of target
1690          *
1691          * @return bool|string activity id
1692          */
1693         public static function activityIDFromContact($cid)
1694         {
1695                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1696                 if (!DBA::isResult($contact)) {
1697                         return false;
1698                 }
1699
1700                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1701                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1702                 return DI::baseUrl() . '/activity/' . $uuid;
1703         }
1704
1705         /**
1706          * Transmits a contact suggestion to a given inbox
1707          *
1708          * @param integer $uid           User ID
1709          * @param string  $inbox         Target inbox
1710          * @param integer $suggestion_id Suggestion ID
1711          *
1712          * @return boolean was the transmission successful?
1713          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1714          */
1715         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1716         {
1717                 $owner = User::getOwnerDataById($uid);
1718
1719                 $suggestion = DI::fsuggest()->getById($suggestion_id);
1720
1721                 $data = ['@context' => ActivityPub::CONTEXT,
1722                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1723                         'type' => 'Announce',
1724                         'actor' => $owner['url'],
1725                         'object' => $suggestion->url,
1726                         'content' => $suggestion->note,
1727                         'instrument' => self::getService(),
1728                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1729                         'cc' => []];
1730
1731                 $signed = LDSignature::sign($data, $owner);
1732
1733                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1734                 return HTTPSignature::transmit($signed, $inbox, $uid);
1735         }
1736
1737         /**
1738          * Transmits a profile relocation to a given inbox
1739          *
1740          * @param integer $uid   User ID
1741          * @param string  $inbox Target inbox
1742          *
1743          * @return boolean was the transmission successful?
1744          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1745          */
1746         public static function sendProfileRelocation($uid, $inbox)
1747         {
1748                 $owner = User::getOwnerDataById($uid);
1749
1750                 $data = ['@context' => ActivityPub::CONTEXT,
1751                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1752                         'type' => 'dfrn:relocate',
1753                         'actor' => $owner['url'],
1754                         'object' => $owner['url'],
1755                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1756                         'instrument' => self::getService(),
1757                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1758                         'cc' => []];
1759
1760                 $signed = LDSignature::sign($data, $owner);
1761
1762                 Logger::log('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1763                 return HTTPSignature::transmit($signed, $inbox, $uid);
1764         }
1765
1766         /**
1767          * Transmits a profile deletion to a given inbox
1768          *
1769          * @param integer $uid   User ID
1770          * @param string  $inbox Target inbox
1771          *
1772          * @return boolean was the transmission successful?
1773          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1774          */
1775         public static function sendProfileDeletion($uid, $inbox)
1776         {
1777                 $owner = User::getOwnerDataById($uid);
1778
1779                 if (empty($owner)) {
1780                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1781                         return false;
1782                 }
1783
1784                 if (empty($owner['uprvkey'])) {
1785                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1786                         return false;
1787                 }
1788
1789                 $data = ['@context' => ActivityPub::CONTEXT,
1790                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1791                         'type' => 'Delete',
1792                         'actor' => $owner['url'],
1793                         'object' => $owner['url'],
1794                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1795                         'instrument' => self::getService(),
1796                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1797                         'cc' => []];
1798
1799                 $signed = LDSignature::sign($data, $owner);
1800
1801                 Logger::log('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1802                 return HTTPSignature::transmit($signed, $inbox, $uid);
1803         }
1804
1805         /**
1806          * Transmits a profile change to a given inbox
1807          *
1808          * @param integer $uid   User ID
1809          * @param string  $inbox Target inbox
1810          *
1811          * @return boolean was the transmission successful?
1812          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1813          * @throws \ImagickException
1814          */
1815         public static function sendProfileUpdate($uid, $inbox)
1816         {
1817                 $owner = User::getOwnerDataById($uid);
1818                 $profile = APContact::getByURL($owner['url']);
1819
1820                 $data = ['@context' => ActivityPub::CONTEXT,
1821                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1822                         'type' => 'Update',
1823                         'actor' => $owner['url'],
1824                         'object' => self::getProfile($uid),
1825                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1826                         'instrument' => self::getService(),
1827                         'to' => [$profile['followers']],
1828                         'cc' => []];
1829
1830                 $signed = LDSignature::sign($data, $owner);
1831
1832                 Logger::log('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub', Logger::DEBUG);
1833                 return HTTPSignature::transmit($signed, $inbox, $uid);
1834         }
1835
1836         /**
1837          * Transmits a given activity to a target
1838          *
1839          * @param string  $activity Type name
1840          * @param string  $target   Target profile
1841          * @param integer $uid      User ID
1842          * @return bool
1843          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1844          * @throws \ImagickException
1845          * @throws \Exception
1846          */
1847         public static function sendActivity($activity, $target, $uid, $id = '')
1848         {
1849                 $profile = APContact::getByURL($target);
1850                 if (empty($profile['inbox'])) {
1851                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1852                         return;
1853                 }
1854
1855                 $owner = User::getOwnerDataById($uid);
1856
1857                 if (empty($id)) {
1858                         $id = DI::baseUrl() . '/activity/' . System::createGUID();
1859                 }
1860
1861                 $data = ['@context' => ActivityPub::CONTEXT,
1862                         'id' => $id,
1863                         'type' => $activity,
1864                         'actor' => $owner['url'],
1865                         'object' => $profile['url'],
1866                         'instrument' => self::getService(),
1867                         'to' => [$profile['url']]];
1868
1869                 Logger::log('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1870
1871                 $signed = LDSignature::sign($data, $owner);
1872                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1873         }
1874
1875         /**
1876          * Transmits a "follow object" activity to a target
1877          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
1878          *
1879          * @param string  $object Object URL
1880          * @param string  $target Target profile
1881          * @param integer $uid    User ID
1882          * @return bool
1883          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1884          * @throws \ImagickException
1885          * @throws \Exception
1886          */
1887         public static function sendFollowObject($object, $target, $uid = 0)
1888         {
1889                 $profile = APContact::getByURL($target);
1890                 if (empty($profile['inbox'])) {
1891                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1892                         return;
1893                 }
1894
1895                 if (empty($uid)) {
1896                         // Fetch the list of administrators
1897                         $admin_mail = explode(',', str_replace(' ', '', DI::config()->get('config', 'admin_email')));
1898
1899                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
1900                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
1901                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
1902                         $uid = $first_user['uid'];
1903                 }
1904
1905                 $condition = ['verb' => Activity::FOLLOW, 'uid' => 0, 'parent-uri' => $object,
1906                         'author-id' => Contact::getPublicIdByUserId($uid)];
1907                 if (Post::exists($condition)) {
1908                         Logger::log('Follow for ' . $object . ' for user ' . $uid . ' does already exist.', Logger::DEBUG);
1909                         return false;
1910                 }
1911
1912                 $owner = User::getOwnerDataById($uid);
1913
1914                 $data = ['@context' => ActivityPub::CONTEXT,
1915                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1916                         'type' => 'Follow',
1917                         'actor' => $owner['url'],
1918                         'object' => $object,
1919                         'instrument' => self::getService(),
1920                         'to' => [$profile['url']]];
1921
1922                 Logger::log('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid, Logger::DEBUG);
1923
1924                 $signed = LDSignature::sign($data, $owner);
1925                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1926         }
1927
1928         /**
1929          * Transmit a message that the contact request had been accepted
1930          *
1931          * @param string  $target Target profile
1932          * @param         $id
1933          * @param integer $uid    User ID
1934          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1935          * @throws \ImagickException
1936          */
1937         public static function sendContactAccept($target, $id, $uid)
1938         {
1939                 $profile = APContact::getByURL($target);
1940                 if (empty($profile['inbox'])) {
1941                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1942                         return;
1943                 }
1944
1945                 $owner = User::getOwnerDataById($uid);
1946                 $data = ['@context' => ActivityPub::CONTEXT,
1947                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1948                         'type' => 'Accept',
1949                         'actor' => $owner['url'],
1950                         'object' => [
1951                                 'id' => (string)$id,
1952                                 'type' => 'Follow',
1953                                 'actor' => $profile['url'],
1954                                 'object' => $owner['url']
1955                         ],
1956                         'instrument' => self::getService(),
1957                         'to' => [$profile['url']]];
1958
1959                 Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
1960
1961                 $signed = LDSignature::sign($data, $owner);
1962                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1963         }
1964
1965         /**
1966          * Reject a contact request or terminates the contact relation
1967          *
1968          * @param string  $target Target profile
1969          * @param         $id
1970          * @param integer $uid    User ID
1971          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1972          * @throws \ImagickException
1973          */
1974         public static function sendContactReject($target, $id, $uid)
1975         {
1976                 $profile = APContact::getByURL($target);
1977                 if (empty($profile['inbox'])) {
1978                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1979                         return;
1980                 }
1981
1982                 $owner = User::getOwnerDataById($uid);
1983                 $data = ['@context' => ActivityPub::CONTEXT,
1984                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1985                         'type' => 'Reject',
1986                         'actor' => $owner['url'],
1987                         'object' => [
1988                                 'id' => (string)$id,
1989                                 'type' => 'Follow',
1990                                 'actor' => $profile['url'],
1991                                 'object' => $owner['url']
1992                         ],
1993                         'instrument' => self::getService(),
1994                         'to' => [$profile['url']]];
1995
1996                 Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
1997
1998                 $signed = LDSignature::sign($data, $owner);
1999                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2000         }
2001
2002         /**
2003          * Transmits a message that we don't want to follow this contact anymore
2004          *
2005          * @param string  $target Target profile
2006          * @param integer $uid    User ID
2007          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2008          * @throws \ImagickException
2009          * @throws \Exception
2010          * @return bool success
2011          */
2012         public static function sendContactUndo($target, $cid, $uid)
2013         {
2014                 $profile = APContact::getByURL($target);
2015                 if (empty($profile['inbox'])) {
2016                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2017                         return false;
2018                 }
2019
2020                 $object_id = self::activityIDFromContact($cid);
2021                 if (empty($object_id)) {
2022                         return false;
2023                 }
2024
2025                 $id = DI::baseUrl() . '/activity/' . System::createGUID();
2026
2027                 $owner = User::getOwnerDataById($uid);
2028                 $data = ['@context' => ActivityPub::CONTEXT,
2029                         'id' => $id,
2030                         'type' => 'Undo',
2031                         'actor' => $owner['url'],
2032                         'object' => ['id' => $object_id, 'type' => 'Follow',
2033                                 'actor' => $owner['url'],
2034                                 'object' => $profile['url']],
2035                         'instrument' => self::getService(),
2036                         'to' => [$profile['url']]];
2037
2038                 Logger::log('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, Logger::DEBUG);
2039
2040                 $signed = LDSignature::sign($data, $owner);
2041                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2042         }
2043
2044         private static function prependMentions($body, int $uriid, string $authorLink)
2045         {
2046                 $mentions = [];
2047
2048                 foreach (Tag::getByURIId($uriid, [Tag::IMPLICIT_MENTION]) as $tag) {
2049                         $profile = Contact::getByURL($tag['url'], false, ['addr', 'contact-type', 'nick']);
2050                         if (!empty($profile['addr'])
2051                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
2052                                 && !strstr($body, $profile['addr'])
2053                                 && !strstr($body, $tag['url'])
2054                                 && $tag['url'] !== $authorLink
2055                         ) {
2056                                 $mentions[] = '@[url=' . $tag['url'] . ']' . $profile['nick'] . '[/url]';
2057                         }
2058                 }
2059
2060                 $mentions[] = $body;
2061
2062                 return implode(' ', $mentions);
2063         }
2064 }