src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Text\BBCode;
  25 use Friendica\Content\Text\HTML;
  26 use Friendica\Content\Text\Markdown;
  27 use Friendica\Core\Logger;
  28 use Friendica\Core\Protocol;
  29 use Friendica\Core\System;
  30 use Friendica\Core\Worker;
  31 use Friendica\Database\DBA;
  32 use Friendica\DI;
  33 use Friendica\Model\APContact;
  34 use Friendica\Model\Contact;
  35 use Friendica\Model\Conversation;
  36 use Friendica\Model\Event;
  37 use Friendica\Model\GServer;
  38 use Friendica\Model\Item;
  39 use Friendica\Model\ItemURI;
  40 use Friendica\Model\Mail;
  41 use Friendica\Model\Tag;
  42 use Friendica\Model\User;
  43 use Friendica\Model\Post;
  44 use Friendica\Protocol\Activity;
  45 use Friendica\Protocol\ActivityPub;
  46 use Friendica\Protocol\Relay;
  47 use Friendica\Util\DateTimeFormat;
  48 use Friendica\Util\JsonLD;
  49 use Friendica\Util\Strings;
  50 use Friendica\Worker\Delivery;
  51
  52 /**
  53  * ActivityPub Processor Protocol class
  54  */
  55 class Processor
  56 {
  57         /**
  58          * Extracts the tag character (#, @, !) from mention links
  59          *
  60          * @param string $body
  61          * @return string
  62          */
  63         protected static function normalizeMentionLinks(string $body): string
  64         {
  65                 return preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  66         }
  67
  68         /**
  69          * Convert the language array into a language JSON
  70          *
  71          * @param array $languages
  72          * @return string language JSON
  73          */
  74         private static function processLanguages(array $languages): string
  75         {
  76                 $codes = array_keys($languages);
  77                 $lang = [];
  78                 foreach ($codes as $code) {
  79                         $lang[$code] = 1;
  80                 }
  81
  82                 if (empty($lang)) {
  83                         return '';
  84                 }
  85
  86                 return json_encode($lang);
  87         }
  88         /**
  89          * Replaces emojis in the body
  90          *
  91          * @param int $uri_id
  92          * @param string $body
  93          * @param array $emojis
  94          *
  95          * @return string with replaced emojis
  96          */
  97         private static function replaceEmojis(int $uri_id, string $body, array $emojis): string
  98         {
  99                 $body = strtr($body,
 100                         array_combine(
 101                                 array_column($emojis, 'name'),
 102                                 array_map(function ($emoji) {
 103                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 104                                 }, $emojis)
 105                         )
 106                 );
 107
 108                 // We store the emoji here to be able to avoid storing it in the media
 109                 foreach ($emojis as $emoji) {
 110                         Post\Link::getByLink($uri_id, $emoji['href']);
 111                 }
 112                 return $body;
 113         }
 114
 115         /**
 116          * Store attached media files in the post-media table
 117          *
 118          * @param int $uriid
 119          * @param array $attachment
 120          * @return void
 121          */
 122         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 123         {
 124                 if (empty($attachment['url'])) {
 125                         return;
 126                 }
 127
 128                 $data = ['uri-id' => $uriid];
 129                 $data['type'] = Post\Media::UNKNOWN;
 130                 $data['url'] = $attachment['url'];
 131                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 132                 $data['height'] = $attachment['height'] ?? null;
 133                 $data['width'] = $attachment['width'] ?? null;
 134                 $data['size'] = $attachment['size'] ?? null;
 135                 $data['preview'] = $attachment['image'] ?? null;
 136                 $data['description'] = $attachment['name'] ?? null;
 137
 138                 Post\Media::insert($data);
 139         }
 140
 141         /**
 142          * Stire attachment data
 143          *
 144          * @param array   $activity
 145          * @param array   $item
 146          */
 147         private static function storeAttachments(array $activity, array $item)
 148         {
 149                 if (empty($activity['attachments'])) {
 150                         return;
 151                 }
 152
 153                 foreach ($activity['attachments'] as $attach) {
 154                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 155                 }
 156         }
 157
 158         /**
 159          * Store attachment data
 160          *
 161          * @param array   $activity
 162          * @param array   $item
 163          */
 164         private static function storeQuestion(array $activity, array $item)
 165         {
 166                 if (empty($activity['question'])) {
 167                         return;
 168                 }
 169                 $question = ['multiple' => $activity['question']['multiple']];
 170
 171                 if (!empty($activity['question']['voters'])) {
 172                         $question['voters'] = $activity['question']['voters'];
 173                 }
 174
 175                 if (!empty($activity['question']['end-time'])) {
 176                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 177                 }
 178
 179                 Post\Question::update($item['uri-id'], $question);
 180
 181                 foreach ($activity['question']['options'] as $key => $option) {
 182                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 183                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 184                 }
 185
 186                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 187         }
 188
 189         /**
 190          * Updates a message
 191          *
 192          * @param FetchQueue $fetchQueue
 193          * @param array      $activity   Activity array
 194          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 195          * @throws \ImagickException
 196          */
 197         public static function updateItem(FetchQueue $fetchQueue, array $activity)
 198         {
 199                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 200                 if (!DBA::isResult($item)) {
 201                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 202                         $item = self::createItem($fetchQueue, $activity);
 203                         if (empty($item)) {
 204                                 return;
 205                         }
 206
 207                         self::postItem($activity, $item);
 208                         return;
 209                 }
 210
 211                 $item['changed'] = DateTimeFormat::utcNow();
 212                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 213
 214                 $item = self::processContent($activity, $item);
 215
 216                 self::storeAttachments($activity, $item);
 217                 self::storeQuestion($activity, $item);
 218
 219                 if (empty($item)) {
 220                         return;
 221                 }
 222
 223                 Post\History::add($item['uri-id'], $item);
 224                 Item::update($item, ['uri' => $activity['id']]);
 225
 226                 DBA::delete('inbox-queue', ['url' => $item['uri']]);
 227
 228                 if ($activity['object_type'] == 'as:Event') {
 229                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 230                         while ($post = DBA::fetch($posts)) {
 231                                 self::updateEvent($post['event-id'], $activity);
 232                         }
 233                 }
 234         }
 235
 236         /**
 237          * Update an existing event
 238          *
 239          * @param int $event_id
 240          * @param array $activity
 241          */
 242         private static function updateEvent(int $event_id, array $activity)
 243         {
 244                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 245
 246                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 247                 $event['summary']  = HTML::toBBCode($activity['name']);
 248                 $event['desc']     = HTML::toBBCode($activity['content']);
 249                 if (!empty($activity['start-time'])) {
 250                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 251                 }
 252                 if (!empty($activity['end-time'])) {
 253                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 254                 }
 255                 $event['nofinish'] = empty($event['finish']);
 256                 $event['location'] = $activity['location'];
 257
 258                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 259                 Event::store($event);
 260         }
 261
 262         /**
 263          * Prepares data for a message
 264          *
 265          * @param FetchQueue $fetchQueue
 266          * @param array      $activity   Activity array
 267          * @return array Internal item
 268          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 269          * @throws \ImagickException
 270          */
 271         public static function createItem(FetchQueue $fetchQueue, array $activity): array
 272         {
 273                 $item = [];
 274                 $item['verb'] = Activity::POST;
 275                 $item['thr-parent'] = $activity['reply-to-id'];
 276
 277                 if ($activity['reply-to-id'] == $activity['id']) {
 278                         $item['gravity'] = GRAVITY_PARENT;
 279                         $item['object-type'] = Activity\ObjectType::NOTE;
 280                 } else {
 281                         $item['gravity'] = GRAVITY_COMMENT;
 282                         $item['object-type'] = Activity\ObjectType::COMMENT;
 283                 }
 284
 285                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 286                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 287                         /**
 288                          * Instead of calling recursively self::fetchMissingActivity which can hit PHP's default function nesting
 289                          * limit of 256 recursive calls, we push the parent activity fetch parameters in this queue. The initial
 290                          * caller is responsible for processing the remaining queue once the original activity has been processed.
 291                          */
 292                         $fetchQueue->push(new FetchQueueItem($activity['reply-to-id'], $activity));
 293                 }
 294
 295                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 296
 297                 /// @todo What to do with $activity['context']?
 298                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 299                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 300                         return [];
 301                 }
 302
 303                 $item['network'] = Protocol::ACTIVITYPUB;
 304                 $item['author-link'] = $activity['author'];
 305                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 306                 $item['owner-link'] = $activity['actor'];
 307                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 308
 309                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 310                         $item['private'] = Item::UNLISTED;
 311                 } elseif (in_array(0, $activity['receiver'])) {
 312                         $item['private'] = Item::PUBLIC;
 313                 } else {
 314                         $item['private'] = Item::PRIVATE;
 315                 }
 316
 317                 if (!empty($activity['raw'])) {
 318                         $item['source'] = $activity['raw'];
 319                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 320                         $item['conversation-href'] = $activity['context'] ?? '';
 321                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 322
 323                         if (isset($activity['push'])) {
 324                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 325                         }
 326                 }
 327
 328                 if (!empty($activity['from-relay'])) {
 329                         $item['direction'] = Conversation::RELAY;
 330                 }
 331
 332                 if ($activity['object_type'] == 'as:Article') {
 333                         $item['post-type'] = Item::PT_ARTICLE;
 334                 } elseif ($activity['object_type'] == 'as:Audio') {
 335                         $item['post-type'] = Item::PT_AUDIO;
 336                 } elseif ($activity['object_type'] == 'as:Document') {
 337                         $item['post-type'] = Item::PT_DOCUMENT;
 338                 } elseif ($activity['object_type'] == 'as:Event') {
 339                         $item['post-type'] = Item::PT_EVENT;
 340                 } elseif ($activity['object_type'] == 'as:Image') {
 341                         $item['post-type'] = Item::PT_IMAGE;
 342                 } elseif ($activity['object_type'] == 'as:Page') {
 343                         $item['post-type'] = Item::PT_PAGE;
 344                 } elseif ($activity['object_type'] == 'as:Question') {
 345                         $item['post-type'] = Item::PT_POLL;
 346                 } elseif ($activity['object_type'] == 'as:Video') {
 347                         $item['post-type'] = Item::PT_VIDEO;
 348                 } else {
 349                         $item['post-type'] = Item::PT_NOTE;
 350                 }
 351
 352                 $item['isForum'] = false;
 353
 354                 if (!empty($activity['thread-completion'])) {
 355                         if ($activity['thread-completion'] != $item['owner-id']) {
 356                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 357                                 $item['causer-link'] = $actor['url'];
 358                                 $item['causer-id'] = $activity['thread-completion'];
 359                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 360                         } else {
 361                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 362                                 $item['causer-link'] = $item['owner-link'];
 363                                 $item['causer-id']   = $item['owner-id'];
 364                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 365                         }
 366
 367                         $item['owner-link'] = $item['author-link'];
 368                         $item['owner-id'] = $item['author-id'];
 369                 } else {
 370                         $actor = APContact::getByURL($item['owner-link'], false);
 371                         $item['isForum'] = ($actor['type'] == 'Group');
 372                 }
 373
 374                 $item['uri'] = $activity['id'];
 375
 376                 if (empty($activity['published']) || empty($activity['updated'])) {
 377                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 378                 }
 379
 380                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 381                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 382                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 383                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 384
 385                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 386                 if (empty($item['uri-id'])) {
 387                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 388                         return [];
 389                 }
 390
 391                 $item = self::processContent($activity, $item);
 392                 if (empty($item)) {
 393                         Logger::info('Message was not processed');
 394                         return [];
 395                 }
 396
 397                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 398
 399                 self::storeAttachments($activity, $item);
 400                 self::storeQuestion($activity, $item);
 401
 402                 // We received the post via AP, so we set the protocol of the server to AP
 403                 $contact = Contact::getById($item['author-id'], ['gsid']);
 404                 if (!empty($contact['gsid'])) {
 405                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 406                 }
 407
 408                 if ($item['author-id'] != $item['owner-id']) {
 409                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 410                         if (!empty($contact['gsid'])) {
 411                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 412                         }
 413                 }
 414
 415                 return $item;
 416         }
 417
 418         /**
 419          * Delete items
 420          *
 421          * @param array $activity
 422          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 423          * @throws \ImagickException
 424          */
 425         public static function deleteItem(array $activity)
 426         {
 427                 $owner = Contact::getIdForURL($activity['actor']);
 428
 429                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 430                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 431         }
 432
 433         /**
 434          * Prepare the item array for an activity
 435          *
 436          * @param array $activity Activity array
 437          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 438          * @throws \ImagickException
 439          */
 440         public static function addTag(array $activity)
 441         {
 442                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 443                         return;
 444                 }
 445
 446                 foreach ($activity['receiver'] as $receiver) {
 447                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 448                         if (!DBA::isResult($item)) {
 449                                 // We don't fetch missing content for this purpose
 450                                 continue;
 451                         }
 452
 453                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 454                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 455                                 continue;
 456                         }
 457
 458                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 459                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 460                 }
 461         }
 462
 463         /**
 464          * Prepare the item array for an activity
 465          *
 466          * @param FetchQueue $fetchQueue
 467          * @param array      $activity   Activity array
 468          * @param string     $verb       Activity verb
 469          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 470          * @throws \ImagickException
 471          */
 472         public static function createActivity(FetchQueue $fetchQueue, array $activity, string $verb)
 473         {
 474                 $item = self::createItem($fetchQueue, $activity);
 475                 if (empty($item)) {
 476                         return;
 477                 }
 478
 479                 $item['verb'] = $verb;
 480                 $item['thr-parent'] = $activity['object_id'];
 481                 $item['gravity'] = GRAVITY_ACTIVITY;
 482                 unset($item['post-type']);
 483                 $item['object-type'] = Activity\ObjectType::NOTE;
 484
 485                 if (!empty($activity['content'])) {
 486                         $item['body'] = HTML::toBBCode($activity['content']);
 487                 }
 488
 489                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 490
 491                 self::postItem($activity, $item);
 492         }
 493
 494         /**
 495          * Fetch the Uri-Id of a post for the "featured" collection
 496          *
 497          * @param array $activity
 498          * @return null|int
 499          */
 500         private static function getUriIdForFeaturedCollection(array $activity)
 501         {
 502                 $actor = APContact::getByURL($activity['actor']);
 503                 if (empty($actor)) {
 504                         return null;
 505                 }
 506
 507                 // Refetch the account when the "featured" collection is missing.
 508                 // This can be removed in a future version (end of 2022 should be good).
 509                 if (empty($actor['featured'])) {
 510                         $actor = APContact::getByURL($activity['actor'], true);
 511                         if (empty($actor)) {
 512                                 return null;
 513                         }
 514                 }
 515
 516                 if ($activity['target_id'] != $actor['featured']) {
 517                         return null;
 518                 }
 519
 520                 $id = Contact::getIdForURL($activity['actor']);
 521                 if (empty($id)) {
 522                         return null;
 523                 }
 524
 525                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id'], 'author-id' => $id]);
 526                 if (!empty($parent['uri-id'])) {
 527                         return $parent['uri-id'];
 528                 }
 529
 530                 return null;
 531         }
 532
 533         /**
 534          * Add a post to the "Featured" collection
 535          *
 536          * @param array $activity
 537          */
 538         public static function addToFeaturedCollection(array $activity)
 539         {
 540                 $uriid = self::getUriIdForFeaturedCollection($activity);
 541                 if (empty($uriid)) {
 542                         return;
 543                 }
 544
 545                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 546
 547                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 548         }
 549
 550         /**
 551          * Remove a post to the "Featured" collection
 552          *
 553          * @param array $activity
 554          */
 555         public static function removeFromFeaturedCollection(array $activity)
 556         {
 557                 $uriid = self::getUriIdForFeaturedCollection($activity);
 558                 if (empty($uriid)) {
 559                         return;
 560                 }
 561
 562                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 563
 564                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 565         }
 566
 567         /**
 568          * Create an event
 569          *
 570          * @param array $activity Activity array
 571          * @param array $item
 572          *
 573          * @return int event id
 574          * @throws \Exception
 575          */
 576         public static function createEvent(array $activity, array $item): int
 577         {
 578                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 579                 $event['desc']      = HTML::toBBCode($activity['content']);
 580                 if (!empty($activity['start-time'])) {
 581                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 582                 }
 583                 if (!empty($activity['end-time'])) {
 584                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 585                 }
 586                 $event['nofinish']  = empty($event['finish']);
 587                 $event['location']  = $activity['location'];
 588                 $event['cid']       = $item['contact-id'];
 589                 $event['uid']       = $item['uid'];
 590                 $event['uri']       = $item['uri'];
 591                 $event['edited']    = $item['edited'];
 592                 $event['private']   = $item['private'];
 593                 $event['guid']      = $item['guid'];
 594                 $event['plink']     = $item['plink'];
 595                 $event['network']   = $item['network'];
 596                 $event['protocol']  = $item['protocol'];
 597                 $event['direction'] = $item['direction'];
 598                 $event['source']    = $item['source'];
 599
 600                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 601                 if (DBA::isResult($ev)) {
 602                         $event['id'] = $ev['id'];
 603                 }
 604
 605                 $event_id = Event::store($event);
 606
 607                 Logger::info('Event was stored', ['id' => $event_id]);
 608
 609                 return $event_id;
 610         }
 611
 612         /**
 613          * Process the content
 614          *
 615          * @param array $activity Activity array
 616          * @param array $item
 617          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 618          * @throws \Exception
 619          */
 620         private static function processContent(array $activity, array $item)
 621         {
 622                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 623                         $item['title'] = strip_tags($activity['name']);
 624                         $content = Markdown::toBBCode($activity['content']);
 625                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 626                         $item['title'] = $activity['name'];
 627                         $content = $activity['content'];
 628                 } else {
 629                         // By default assume "text/html"
 630                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 631                         $content = HTML::toBBCode($activity['content'] ?? '');
 632                 }
 633
 634                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 635
 636                 if (!empty($activity['languages'])) {
 637                         $item['language'] = self::processLanguages($activity['languages']);
 638                 }
 639
 640                 if (!empty($activity['emojis'])) {
 641                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 642                 }
 643
 644                 $content = self::addMentionLinks($content, $activity['tags']);
 645
 646                 if (!empty($activity['source'])) {
 647                         $item['body'] = $activity['source'];
 648                         $item['raw-body'] = $content;
 649                         $item['body'] = Item::improveSharedDataInBody($item);
 650                 } else {
 651                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 652                                 $item_private = !in_array(0, $activity['item_receiver']);
 653                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 654                                 if (!DBA::isResult($parent)) {
 655                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 656                                         return false;
 657                                 }
 658                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 659                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 660                                         return false;
 661                                 }
 662
 663                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 664                         }
 665                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 666                         $item['raw-body'] = $item['body'] = $content;
 667                 }
 668
 669                 self::storeFromBody($item);
 670                 self::storeTags($item['uri-id'], $activity['tags']);
 671
 672                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 673
 674                 $item['location'] = $activity['location'];
 675
 676                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 677                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 678                 }
 679
 680                 $item['app'] = $activity['generator'];
 681
 682                 return $item;
 683         }
 684
 685         /**
 686          * Store hashtags and mentions
 687          *
 688          * @param array $item
 689          */
 690         private static function storeFromBody(array $item)
 691         {
 692                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 693                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 694
 695                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 696         }
 697
 698         /**
 699          * Generate a GUID out of an URL of an ActivityPub post.
 700          *
 701          * @param string $url message URL
 702          * @return string with GUID
 703          */
 704         private static function getGUIDByURL(string $url): string
 705         {
 706                 $parsed = parse_url($url);
 707
 708                 $host_hash = hash('crc32', $parsed['host']);
 709
 710                 unset($parsed["scheme"]);
 711                 unset($parsed["host"]);
 712
 713                 $path = implode("/", $parsed);
 714
 715                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 716         }
 717
 718         /**
 719          * Checks if an incoming message is wanted
 720          *
 721          * @param array $activity
 722          * @param array $item
 723          * @return boolean Is the message wanted?
 724          */
 725         private static function isSolicitedMessage(array $activity, array $item): bool
 726         {
 727                 // The checks are split to improve the support when searching why a message was accepted.
 728                 if (count($activity['receiver']) != 1) {
 729                         // The message has more than one receiver, so it is wanted.
 730                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 731                         return true;
 732                 }
 733
 734                 if ($item['private'] == Item::PRIVATE) {
 735                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 736                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 737                         return true;
 738                 }
 739
 740                 if (!empty($activity['from-relay'])) {
 741                         // We check relay posts at another place. When it arrived here, the message is already checked.
 742                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 743                         return true;
 744                 }
 745
 746                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 747                         // Manual completions and completions caused by reshares are allowed without any further checks.
 748                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 749                         return true;
 750                 }
 751
 752                 if ($item['gravity'] != GRAVITY_PARENT) {
 753                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 754                         // This can possibly be improved in the future.
 755                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 756                         return true;
 757                 }
 758
 759                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 760                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 761                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 762                         return true;
 763                 } else {
 764                         return false;
 765                 }
 766         }
 767
 768         /**
 769          * Creates an item post
 770          *
 771          * @param array $activity Activity data
 772          * @param array $item     item array
 773          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 774          * @throws \ImagickException
 775          */
 776         public static function postItem(array $activity, array $item)
 777         {
 778                 if (empty($item)) {
 779                         return;
 780                 }
 781
 782                 $stored = false;
 783                 ksort($activity['receiver']);
 784
 785                 if (!self::isSolicitedMessage($activity, $item)) {
 786                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 787                         return;
 788                 }
 789
 790                 foreach ($activity['receiver'] as $receiver) {
 791                         if ($receiver == -1) {
 792                                 continue;
 793                         }
 794
 795                         $item['uid'] = $receiver;
 796
 797                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 798                         switch($type) {
 799                                 case Receiver::TARGET_TO:
 800                                         $item['post-reason'] = Item::PR_TO;
 801                                         break;
 802                                 case Receiver::TARGET_CC:
 803                                         $item['post-reason'] = Item::PR_CC;
 804                                         break;
 805                                 case Receiver::TARGET_BTO:
 806                                         $item['post-reason'] = Item::PR_BTO;
 807                                         break;
 808                                 case Receiver::TARGET_BCC:
 809                                         $item['post-reason'] = Item::PR_BCC;
 810                                         break;
 811                                 case Receiver::TARGET_FOLLOWER:
 812                                         $item['post-reason'] = Item::PR_FOLLOWER;
 813                                         break;
 814                                 case Receiver::TARGET_ANSWER:
 815                                         $item['post-reason'] = Item::PR_COMMENT;
 816                                         break;
 817                                 case Receiver::TARGET_GLOBAL:
 818                                         $item['post-reason'] = Item::PR_GLOBAL;
 819                                         break;
 820                                 default:
 821                                         $item['post-reason'] = Item::PR_NONE;
 822                         }
 823
 824                         if (!empty($activity['from-relay'])) {
 825                                 $item['post-reason'] = Item::PR_RELAY;
 826                         } elseif (!empty($activity['thread-completion'])) {
 827                                 $item['post-reason'] = Item::PR_FETCHED;
 828                         }
 829
 830                         if ($item['isForum'] ?? false) {
 831                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 832                         } else {
 833                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 834                         }
 835
 836                         if (($receiver != 0) && empty($item['contact-id'])) {
 837                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 838                         }
 839
 840                         if (!empty($activity['directmessage'])) {
 841                                 self::postMail($activity, $item);
 842                                 continue;
 843                         }
 844
 845                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 846                                 if ($item['post-reason'] == Item::PR_BCC) {
 847                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 848                                         continue;
 849                                 }
 850
 851                                 if (
 852                                         !empty($activity['thread-children-type'])
 853                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 854                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 855                                 ) {
 856                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 857                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 858                                         continue;
 859                                 }
 860                         }
 861
 862                         $is_forum = false;
 863
 864                         if ($receiver != 0) {
 865                                 $user = User::getById($receiver, ['account-type']);
 866                                 if (!empty($user['account-type'])) {
 867                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 868                                 }
 869                         }
 870
 871                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 872                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 873
 874                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 875                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 876                                 }
 877
 878                                 if ($skip) {
 879                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 880                                         continue;
 881                                 }
 882
 883                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 884                         }
 885
 886                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 887                                 $event_id = self::createEvent($activity, $item);
 888
 889                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 890                         }
 891
 892                         $item_id = Item::insert($item);
 893                         if ($item_id) {
 894                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 895                                 DBA::delete('inbox-queue', ['url' => $item['uri']]);
 896                         } else {
 897                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 898                         }
 899
 900                         if ($item['uid'] == 0) {
 901                                 $stored = $item_id;
 902                         }
 903                 }
 904
 905                 // Store send a follow request for every reshare - but only when the item had been stored
 906                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
 907                         $author = APContact::getByURL($item['owner-link'], false);
 908                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 909                         if ($author['type'] != 'Group') {
 910                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 911                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 912                         }
 913                 }
 914         }
 915
 916         /**
 917          * Store tags and mentions into the tag table
 918          *
 919          * @param integer $uriid
 920          * @param array $tags
 921          */
 922         private static function storeTags(int $uriid, array $tags = null)
 923         {
 924                 foreach ($tags as $tag) {
 925                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 926                                 continue;
 927                         }
 928
 929                         $hash = substr($tag['name'], 0, 1);
 930
 931                         if ($tag['type'] == 'Mention') {
 932                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 933                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 934                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 935                                         $tag['name'] = substr($tag['name'], 1);
 936                                 }
 937                                 $type = Tag::IMPLICIT_MENTION;
 938
 939                                 if (!empty($tag['href'])) {
 940                                         $apcontact = APContact::getByURL($tag['href']);
 941                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 942                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 943                                         }
 944                                 }
 945                         } elseif ($tag['type'] == 'Hashtag') {
 946                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 947                                         $tag['name'] = substr($tag['name'], 1);
 948                                 }
 949                                 $type = Tag::HASHTAG;
 950                         }
 951
 952                         if (empty($tag['name'])) {
 953                                 continue;
 954                         }
 955
 956                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 957                 }
 958         }
 959
 960         public static function storeReceivers(int $uriid, array $receivers)
 961         {
 962                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
 963                         if (!empty($receivers[$element])) {
 964                                 foreach ($receivers[$element] as $receiver) {
 965                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
 966                                                 $name = Receiver::PUBLIC_COLLECTION;
 967                                         } else {
 968                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
 969                                         }
 970
 971                                         $target = Tag::getTargetType($receiver);
 972                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
 973                                         Tag::store($uriid, $type, $name, $receiver, $target);
 974                                 }
 975                         }
 976                 }
 977         }
 978
 979         /**
 980          * Creates an mail post
 981          *
 982          * @param array $activity Activity data
 983          * @param array $item     item array
 984          * @return int|bool New mail table row id or false on error
 985          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 986          */
 987         private static function postMail(array $activity, array $item)
 988         {
 989                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 990                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 991                         return false;
 992                 }
 993
 994                 Logger::info('Direct Message', $item);
 995
 996                 $msg = [];
 997                 $msg['uid'] = $item['uid'];
 998
 999                 $msg['contact-id'] = $item['contact-id'];
1000
1001                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1002                 $msg['from-name'] = $contact['name'];
1003                 $msg['from-url'] = $contact['url'];
1004                 $msg['from-photo'] = $contact['photo'];
1005
1006                 $msg['uri'] = $item['uri'];
1007                 $msg['created'] = $item['created'];
1008
1009                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1010                 if (DBA::isResult($parent)) {
1011                         $msg['parent-uri'] = $parent['parent-uri'];
1012                         $msg['title'] = $parent['title'];
1013                 } else {
1014                         $msg['parent-uri'] = $item['thr-parent'];
1015
1016                         if (!empty($item['title'])) {
1017                                 $msg['title'] = $item['title'];
1018                         } elseif (!empty($item['content-warning'])) {
1019                                 $msg['title'] = $item['content-warning'];
1020                         } else {
1021                                 // Trying to generate a title out of the body
1022                                 $title = $item['body'];
1023
1024                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1025                                         $title = $matches[3];
1026                                 }
1027
1028                                 $title = trim(BBCode::toPlaintext($title));
1029
1030                                 if (strlen($title) > 20) {
1031                                         $title = substr($title, 0, 20) . '...';
1032                                 }
1033
1034                                 $msg['title'] = $title;
1035                         }
1036                 }
1037                 $msg['body'] = $item['body'];
1038
1039                 return Mail::insert($msg);
1040         }
1041
1042         /**
1043          * Fetch featured posts from a contact with the given url
1044          *
1045          * @param string $url
1046          * @return void
1047          */
1048         public static function fetchFeaturedPosts(string $url)
1049         {
1050                 Logger::info('Fetch featured posts', ['contact' => $url]);
1051
1052                 $apcontact = APContact::getByURL($url);
1053                 if (empty($apcontact['featured'])) {
1054                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1055                         return;
1056                 }
1057
1058                 $pcid = Contact::getIdForURL($url, 0, false);
1059                 if (empty($pcid)) {
1060                         Logger::info('Contact not found', ['contact' => $url]);
1061                         return;
1062                 }
1063
1064                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1065                 if (!empty($posts)) {
1066                         $old_featured = array_column($posts, 'uri-id');
1067                 } else {
1068                         $old_featured = [];
1069                 }
1070
1071                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1072                 if (empty($featured)) {
1073                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1074
1075                         foreach ($old_featured as $uri_id) {
1076                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1077                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1078                         }
1079                         return;
1080                 }
1081
1082                 $new = 0;
1083                 $old = 0;
1084
1085                 foreach ($featured as $post) {
1086                         if (empty($post['id'])) {
1087                                 continue;
1088                         }
1089                         $id = Item::fetchByLink($post['id']);
1090                         if (!empty($id)) {
1091                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1092                                 if (!empty($item['uri-id'])) {
1093                                         if (!$item['featured']) {
1094                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1095                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1096                                                 $new++;
1097                                         } else {
1098                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1099                                                 $old++;
1100                                         }
1101
1102                                         $index = array_search($item['uri-id'], $old_featured);
1103                                         if (!($index === false)) {
1104                                                 unset($old_featured[$index]);
1105                                         }
1106                                 }
1107                         }
1108                 }
1109
1110                 foreach ($old_featured as $uri_id) {
1111                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1112                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1113                 }
1114
1115                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1116         }
1117
1118         /**
1119          * Fetches missing posts
1120          *
1121          * @param FetchQueue $fetchQueue
1122          * @param string     $url         message URL
1123          * @param array      $child       activity array with the child of this message
1124          * @param string     $relay_actor Relay actor
1125          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1126          * @return string fetched message URL
1127          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1128          * @throws \ImagickException
1129          */
1130         public static function fetchMissingActivity(FetchQueue $fetchQueue, string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL): string
1131         {
1132                 if (!empty($child['receiver'])) {
1133                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1134                 } else {
1135                         $uid = 0;
1136                 }
1137
1138                 $object = ActivityPub::fetchContent($url, $uid);
1139                 if (empty($object)) {
1140                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url]);
1141                         return '';
1142                 }
1143
1144                 if (empty($object['id'])) {
1145                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1146                         return '';
1147                 }
1148
1149                 if (!empty($object['actor'])) {
1150                         $object_actor = $object['actor'];
1151                 } elseif (!empty($object['attributedTo'])) {
1152                         $object_actor = $object['attributedTo'];
1153                         if (is_array($object_actor)) {
1154                                 $compacted = JsonLD::compact($object);
1155                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1156                         }
1157                 } else {
1158                         // Shouldn't happen
1159                         $object_actor = '';
1160                 }
1161
1162                 $signer = [$object_actor];
1163
1164                 if (!empty($child['author'])) {
1165                         $actor = $child['author'];
1166                         $signer[] = $actor;
1167                 } else {
1168                         $actor = $object_actor;
1169                 }
1170
1171                 if (!empty($object['published'])) {
1172                         $published = $object['published'];
1173                 } elseif (!empty($child['published'])) {
1174                         $published = $child['published'];
1175                 } else {
1176                         $published = DateTimeFormat::utcNow();
1177                 }
1178
1179                 $activity = [];
1180                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1181                 unset($object['@context']);
1182                 $activity['id'] = $object['id'];
1183                 $activity['to'] = $object['to'] ?? [];
1184                 $activity['cc'] = $object['cc'] ?? [];
1185                 $activity['actor'] = $actor;
1186                 $activity['object'] = $object;
1187                 $activity['published'] = $published;
1188                 $activity['type'] = 'Create';
1189
1190                 $ldactivity = JsonLD::compact($activity);
1191
1192                 if (!empty($relay_actor)) {
1193                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1194                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1195                 } elseif (!empty($child['thread-completion'])) {
1196                         $ldactivity['thread-completion'] = $child['thread-completion'];
1197                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1198                 } else {
1199                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1200                         $ldactivity['completion-mode']   = $completion;
1201                 }
1202
1203                 if (!empty($child['type'])) {
1204                         $ldactivity['thread-children-type'] = $child['type'];
1205                 }
1206
1207                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1208                         return '';
1209                 }
1210
1211                 ActivityPub\Receiver::processActivity($fetchQueue, $ldactivity, json_encode($activity), $uid, true, false, $signer);
1212
1213                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1214
1215                 return $activity['id'];
1216         }
1217
1218         /**
1219          * Test if incoming relay messages should be accepted
1220          *
1221          * @param array $activity activity array
1222          * @param string $id      object ID
1223          * @return boolean true if message is accepted
1224          */
1225         private static function acceptIncomingMessage(array $activity, string $id): bool
1226         {
1227                 if (empty($activity['as:object'])) {
1228                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1229                         return true;
1230                 }
1231
1232                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1233                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1234                 if (Post::exists(['uri-id' => $uriid])) {
1235                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1236                         return true;
1237                 }
1238
1239                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1240                 $authorid = Contact::getIdForURL($attributed_to);
1241
1242                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1243
1244                 $messageTags = [];
1245                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1246                 if (!empty($tags)) {
1247                         foreach ($tags as $tag) {
1248                                 if ($tag['type'] != 'Hashtag') {
1249                                         continue;
1250                                 }
1251                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1252                         }
1253                 }
1254
1255                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1256         }
1257
1258         /**
1259          * perform a "follow" request
1260          *
1261          * @param array $activity
1262          * @return void
1263          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1264          * @throws \ImagickException
1265          */
1266         public static function followUser(array $activity)
1267         {
1268                 $uid = User::getIdForURL($activity['object_id']);
1269                 if (empty($uid)) {
1270                         return;
1271                 }
1272
1273                 $owner = User::getOwnerDataById($uid);
1274                 if (empty($owner)) {
1275                         return;
1276                 }
1277
1278                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1279                 if (!empty($cid)) {
1280                         self::switchContact($cid);
1281                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1282                 }
1283
1284                 $item = [
1285                         'author-id' => Contact::getIdForURL($activity['actor']),
1286                         'author-link' => $activity['actor'],
1287                 ];
1288
1289                 // Ensure that the contact has got the right network type
1290                 self::switchContact($item['author-id']);
1291
1292                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1293                 if ($result === true) {
1294                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1295                 }
1296
1297                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1298                 if (empty($cid)) {
1299                         return;
1300                 }
1301
1302                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1303                         self::transmitPendingEvents($cid, $owner['uid']);
1304                 }
1305
1306                 if (empty($contact)) {
1307                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1308                 }
1309
1310                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1311         }
1312
1313         /**
1314          * Transmit pending events to the new follower
1315          *
1316          * @param integer $cid Contact id
1317          * @param integer $uid User id
1318          * @return void
1319          */
1320         private static function transmitPendingEvents(int $cid, int $uid)
1321         {
1322                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1323                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1324
1325                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1326                 while ($event = DBA::fetch($events)) {
1327                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1328                         if (empty($post)) {
1329                                 continue;
1330                         }
1331                         if (DI::config()->get('system', 'bulk_delivery')) {
1332                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1333                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1334                         } else {
1335                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1336                         }
1337                 }
1338         }
1339
1340         /**
1341          * Update the given profile
1342          *
1343          * @param array $activity
1344          * @throws \Exception
1345          */
1346         public static function updatePerson(array $activity)
1347         {
1348                 if (empty($activity['object_id'])) {
1349                         return;
1350                 }
1351
1352                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1353                 Contact::updateFromProbeByURL($activity['object_id']);
1354         }
1355
1356         /**
1357          * Delete the given profile
1358          *
1359          * @param array $activity
1360          * @return void
1361          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1362          */
1363         public static function deletePerson(array $activity)
1364         {
1365                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1366                         Logger::info('Empty object id or actor.');
1367                         return;
1368                 }
1369
1370                 if ($activity['object_id'] != $activity['actor']) {
1371                         Logger::info('Object id does not match actor.');
1372                         return;
1373                 }
1374
1375                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1376                 while ($contact = DBA::fetch($contacts)) {
1377                         Contact::remove($contact['id']);
1378                 }
1379                 DBA::close($contacts);
1380
1381                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1382         }
1383
1384         /**
1385          * Blocks the user by the contact
1386          *
1387          * @param array $activity
1388          * @return void
1389          * @throws \Exception
1390          */
1391         public static function blockAccount(array $activity)
1392         {
1393                 $cid = Contact::getIdForURL($activity['actor']);
1394                 if (empty($cid)) {
1395                         return;
1396                 }
1397
1398                 $uid = User::getIdForURL($activity['object_id']);
1399                 if (empty($uid)) {
1400                         return;
1401                 }
1402
1403                 Contact\User::setIsBlocked($cid, $uid, true);
1404
1405                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1406         }
1407
1408         /**
1409          * Unblocks the user by the contact
1410          *
1411          * @param array $activity
1412          * @return void
1413          * @throws \Exception
1414          */
1415         public static function unblockAccount(array $activity)
1416         {
1417                 $cid = Contact::getIdForURL($activity['actor']);
1418                 if (empty($cid)) {
1419                         return;
1420                 }
1421
1422                 $uid = User::getIdForURL($activity['object_object']);
1423                 if (empty($uid)) {
1424                         return;
1425                 }
1426
1427                 Contact\User::setIsBlocked($cid, $uid, false);
1428
1429                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1430         }
1431
1432         /**
1433          * Accept a follow request
1434          *
1435          * @param array $activity
1436          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1437          * @throws \ImagickException
1438          */
1439         public static function acceptFollowUser(array $activity)
1440         {
1441                 $uid = User::getIdForURL($activity['object_actor']);
1442                 if (empty($uid)) {
1443                         return;
1444                 }
1445
1446                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1447                 if (empty($cid)) {
1448                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1449                         return;
1450                 }
1451
1452                 self::switchContact($cid);
1453
1454                 $fields = ['pending' => false];
1455
1456                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1457                 if ($contact['rel'] == Contact::FOLLOWER) {
1458                         $fields['rel'] = Contact::FRIEND;
1459                 }
1460
1461                 $condition = ['id' => $cid];
1462                 Contact::update($fields, $condition);
1463                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1464         }
1465
1466         /**
1467          * Reject a follow request
1468          *
1469          * @param array $activity
1470          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1471          * @throws \ImagickException
1472          */
1473         public static function rejectFollowUser(array $activity)
1474         {
1475                 $uid = User::getIdForURL($activity['object_actor']);
1476                 if (empty($uid)) {
1477                         return;
1478                 }
1479
1480                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1481                 if (empty($cid)) {
1482                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1483                         return;
1484                 }
1485
1486                 self::switchContact($cid);
1487
1488                 $contact = Contact::getById($cid, ['rel']);
1489                 if ($contact['rel'] == Contact::SHARING) {
1490                         Contact::remove($cid);
1491                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1492                 } elseif ($contact['rel'] == Contact::FRIEND) {
1493                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1494                 } else {
1495                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1496                 }
1497         }
1498
1499         /**
1500          * Undo activity like "like" or "dislike"
1501          *
1502          * @param array $activity
1503          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1504          * @throws \ImagickException
1505          */
1506         public static function undoActivity(array $activity)
1507         {
1508                 if (empty($activity['object_id'])) {
1509                         return;
1510                 }
1511
1512                 if (empty($activity['object_actor'])) {
1513                         return;
1514                 }
1515
1516                 $author_id = Contact::getIdForURL($activity['object_actor']);
1517                 if (empty($author_id)) {
1518                         return;
1519                 }
1520
1521                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1522         }
1523
1524         /**
1525          * Activity to remove a follower
1526          *
1527          * @param array $activity
1528          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1529          * @throws \ImagickException
1530          */
1531         public static function undoFollowUser(array $activity)
1532         {
1533                 $uid = User::getIdForURL($activity['object_object']);
1534                 if (empty($uid)) {
1535                         return;
1536                 }
1537
1538                 $owner = User::getOwnerDataById($uid);
1539                 if (empty($owner)) {
1540                         return;
1541                 }
1542
1543                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1544                 if (empty($cid)) {
1545                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1546                         return;
1547                 }
1548
1549                 self::switchContact($cid);
1550
1551                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1552                 if (!DBA::isResult($contact)) {
1553                         return;
1554                 }
1555
1556                 Contact::removeFollower($contact);
1557                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1558         }
1559
1560         /**
1561          * Switches a contact to AP if needed
1562          *
1563          * @param integer $cid Contact ID
1564          * @return void
1565          * @throws \Exception
1566          */
1567         private static function switchContact(int $cid)
1568         {
1569                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1570                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1571                         return;
1572                 }
1573
1574                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1575                 Contact::updateFromProbe($cid);
1576         }
1577
1578         /**
1579          * Collects implicit mentions like:
1580          * - the author of the parent item
1581          * - all the mentioned conversants in the parent item
1582          *
1583          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1584          * @return array
1585          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1586          */
1587         private static function getImplicitMentionList(array $parent): array
1588         {
1589                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1590
1591                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1592
1593                 $implicit_mentions = [];
1594                 if (empty($parent_author['url'])) {
1595                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1596                 } else {
1597                         $implicit_mentions[] = $parent_author['url'];
1598                         $implicit_mentions[] = $parent_author['nurl'];
1599                         $implicit_mentions[] = $parent_author['alias'];
1600                 }
1601
1602                 if (!empty($parent['alias'])) {
1603                         $implicit_mentions[] = $parent['alias'];
1604                 }
1605
1606                 foreach ($parent_terms as $term) {
1607                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1608                         if (!empty($contact['url'])) {
1609                                 $implicit_mentions[] = $contact['url'];
1610                                 $implicit_mentions[] = $contact['nurl'];
1611                                 $implicit_mentions[] = $contact['alias'];
1612                         }
1613                 }
1614
1615                 return $implicit_mentions;
1616         }
1617
1618         /**
1619          * Strips from the body prepended implicit mentions
1620          *
1621          * @param string $body
1622          * @param array $parent
1623          * @return string
1624          */
1625         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
1626         {
1627                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1628                         return $body;
1629                 }
1630
1631                 $potential_mentions = self::getImplicitMentionList($parent);
1632
1633                 $kept_mentions = [];
1634
1635                 // Extract one prepended mention at a time from the body
1636                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1637                         if (!in_array($matches[2], $potential_mentions)) {
1638                                 $kept_mentions[] = $matches[1];
1639                         }
1640
1641                         $body = $matches[3];
1642                 }
1643
1644                 // Re-appending the kept mentions to the body after extraction
1645                 $kept_mentions[] = $body;
1646
1647                 return implode('', $kept_mentions);
1648         }
1649
1650         /**
1651          * Adds links to string mentions
1652          *
1653          * @param string $body
1654          * @param array  $tags
1655          * @return string
1656          */
1657         protected static function addMentionLinks(string $body, array $tags): string
1658         {
1659                 // This prevents links to be added again to Pleroma-style mention links
1660                 $body = self::normalizeMentionLinks($body);
1661
1662                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1663                         foreach ($tags as $tag) {
1664                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1665                                         continue;
1666                                 }
1667
1668                                 $hash = substr($tag['name'], 0, 1);
1669                                 $name = substr($tag['name'], 1);
1670                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1671                                         $hash = '';
1672                                         $name = $tag['name'];
1673                                 }
1674
1675                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1676                         }
1677
1678                         return $body;
1679                 });
1680
1681                 return $body;
1682         }
1683 }