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 array      $activity   Activity array
 193          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 194          * @throws \ImagickException
 195          */
 196         public static function updateItem(array $activity)
 197         {
 198                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 199                 if (!DBA::isResult($item)) {
 200                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 201                         $item = self::createItem($activity);
 202                         if (empty($item)) {
 203                                 return;
 204                         }
 205
 206                         self::postItem($activity, $item);
 207                         return;
 208                 }
 209
 210                 $item['changed'] = DateTimeFormat::utcNow();
 211                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 212
 213                 $item = self::processContent($activity, $item);
 214
 215                 self::storeAttachments($activity, $item);
 216                 self::storeQuestion($activity, $item);
 217
 218                 if (empty($item)) {
 219                         return;
 220                 }
 221
 222                 Post\History::add($item['uri-id'], $item);
 223                 Item::update($item, ['uri' => $activity['id']]);
 224
 225                 Queue::remove($activity);
 226
 227                 if ($activity['object_type'] == 'as:Event') {
 228                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 229                         while ($post = DBA::fetch($posts)) {
 230                                 self::updateEvent($post['event-id'], $activity);
 231                         }
 232                 }
 233         }
 234
 235         /**
 236          * Update an existing event
 237          *
 238          * @param int $event_id
 239          * @param array $activity
 240          */
 241         private static function updateEvent(int $event_id, array $activity)
 242         {
 243                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 244
 245                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 246                 $event['summary']  = HTML::toBBCode($activity['name']);
 247                 $event['desc']     = HTML::toBBCode($activity['content']);
 248                 if (!empty($activity['start-time'])) {
 249                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 250                 }
 251                 if (!empty($activity['end-time'])) {
 252                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 253                 }
 254                 $event['nofinish'] = empty($event['finish']);
 255                 $event['location'] = $activity['location'];
 256
 257                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 258                 Event::store($event);
 259         }
 260
 261         /**
 262          * Prepares data for a message
 263          *
 264          * @param array      $activity   Activity array
 265          * @return array Internal item
 266          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 267          * @throws \ImagickException
 268          */
 269         public static function createItem(array $activity): array
 270         {
 271                 $item = [];
 272                 $item['verb'] = Activity::POST;
 273                 $item['thr-parent'] = $activity['reply-to-id'];
 274
 275                 if ($activity['reply-to-id'] == $activity['id']) {
 276                         $item['gravity'] = GRAVITY_PARENT;
 277                         $item['object-type'] = Activity\ObjectType::NOTE;
 278                 } else {
 279                         $item['gravity'] = GRAVITY_COMMENT;
 280                         $item['object-type'] = Activity\ObjectType::COMMENT;
 281                 }
 282
 283                 if (!empty($activity['context'])) {
 284                         $item['conversation'] = $activity['context'];
 285                 } elseif (!empty($activity['conversation'])) {
 286                         $item['conversation'] = $activity['conversation'];
 287                 }
 288
 289                 if (!empty($item['conversation'])) {
 290                         $conversation = Post::selectFirstThread(['uri'], ['conversation' => $item['conversation']]);
 291                         if (!empty($conversation)) {
 292                                 Logger::debug('Got conversation', ['conversation' => $item['conversation'], 'parent' => $conversation]);
 293                                 $item['parent-uri'] = $conversation['uri'];
 294                         }
 295                 } else {
 296                         $conversation = [];
 297                 }
 298
 299                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 300                         $recursion_depth = $activity['recursion-depth'] ?? 0;
 301                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 302                         if ($recursion_depth < 10) {
 303                                 $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 304                                 $fetch_by_worker = empty($result);
 305                         } else {
 306                                 Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 307                                 $fetch_by_worker = true;
 308                         }
 309
 310                         if ($fetch_by_worker && Queue::hasWorker($activity)) {
 311                                 Logger::notice('There is already a worker task to fetch the post.', ['id' => $activity['id'], 'parent' => $activity['reply-to-id']]);
 312                                 $fetch_by_worker = false;
 313                                 if (!empty($conversation)) {
 314                                         return [];
 315                                 }
 316                         }
 317
 318                         if ($fetch_by_worker) {
 319                                 Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 320                                 $activity['recursion-depth'] = 0;
 321                                 $wid = Worker::add(PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 322                                 Queue::setWorkerId($activity, $wid);
 323                                 if (!empty($conversation)) {
 324                                         return [];
 325                                 }
 326                         } elseif (!empty($result)) {
 327                                 if (($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 328                                         $item['thr-parent'] = $result;
 329                                 }
 330                         }
 331                 }
 332
 333                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 334
 335                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 336                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 337                         return [];
 338                 }
 339
 340                 $item['network'] = Protocol::ACTIVITYPUB;
 341                 $item['author-link'] = $activity['author'];
 342                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 343                 $item['owner-link'] = $activity['actor'];
 344                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 345
 346                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 347                         $item['private'] = Item::UNLISTED;
 348                 } elseif (in_array(0, $activity['receiver'])) {
 349                         $item['private'] = Item::PUBLIC;
 350                 } else {
 351                         $item['private'] = Item::PRIVATE;
 352                 }
 353
 354                 if (!empty($activity['raw'])) {
 355                         $item['source'] = $activity['raw'];
 356                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 357                         $item['conversation-href'] = $activity['context'] ?? '';
 358                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 359
 360                         if (isset($activity['push'])) {
 361                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 362                         }
 363                 }
 364
 365                 if (!empty($activity['from-relay'])) {
 366                         $item['direction'] = Conversation::RELAY;
 367                 }
 368
 369                 if ($activity['object_type'] == 'as:Article') {
 370                         $item['post-type'] = Item::PT_ARTICLE;
 371                 } elseif ($activity['object_type'] == 'as:Audio') {
 372                         $item['post-type'] = Item::PT_AUDIO;
 373                 } elseif ($activity['object_type'] == 'as:Document') {
 374                         $item['post-type'] = Item::PT_DOCUMENT;
 375                 } elseif ($activity['object_type'] == 'as:Event') {
 376                         $item['post-type'] = Item::PT_EVENT;
 377                 } elseif ($activity['object_type'] == 'as:Image') {
 378                         $item['post-type'] = Item::PT_IMAGE;
 379                 } elseif ($activity['object_type'] == 'as:Page') {
 380                         $item['post-type'] = Item::PT_PAGE;
 381                 } elseif ($activity['object_type'] == 'as:Question') {
 382                         $item['post-type'] = Item::PT_POLL;
 383                 } elseif ($activity['object_type'] == 'as:Video') {
 384                         $item['post-type'] = Item::PT_VIDEO;
 385                 } else {
 386                         $item['post-type'] = Item::PT_NOTE;
 387                 }
 388
 389                 $item['isForum'] = false;
 390
 391                 if (!empty($activity['thread-completion'])) {
 392                         if ($activity['thread-completion'] != $item['owner-id']) {
 393                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 394                                 $item['causer-link'] = $actor['url'];
 395                                 $item['causer-id'] = $activity['thread-completion'];
 396                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 397                         } else {
 398                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 399                                 $item['causer-link'] = $item['owner-link'];
 400                                 $item['causer-id']   = $item['owner-id'];
 401                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 402                         }
 403
 404                         $item['owner-link'] = $item['author-link'];
 405                         $item['owner-id'] = $item['author-id'];
 406                 } else {
 407                         $actor = APContact::getByURL($item['owner-link'], false);
 408                         $item['isForum'] = ($actor['type'] == 'Group');
 409                 }
 410
 411                 $item['uri'] = $activity['id'];
 412
 413                 if (empty($activity['published']) || empty($activity['updated'])) {
 414                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 415                 }
 416
 417                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 418                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 419                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 420                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 421
 422                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 423                 if (empty($item['uri-id'])) {
 424                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 425                         return [];
 426                 }
 427
 428                 $item = self::processContent($activity, $item);
 429                 if (empty($item)) {
 430                         Logger::info('Message was not processed');
 431                         return [];
 432                 }
 433
 434                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 435
 436                 self::storeAttachments($activity, $item);
 437                 self::storeQuestion($activity, $item);
 438
 439                 // We received the post via AP, so we set the protocol of the server to AP
 440                 $contact = Contact::getById($item['author-id'], ['gsid']);
 441                 if (!empty($contact['gsid'])) {
 442                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 443                 }
 444
 445                 if ($item['author-id'] != $item['owner-id']) {
 446                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 447                         if (!empty($contact['gsid'])) {
 448                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 449                         }
 450                 }
 451
 452                 return $item;
 453         }
 454
 455         /**
 456          * Delete items
 457          *
 458          * @param array $activity
 459          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 460          * @throws \ImagickException
 461          */
 462         public static function deleteItem(array $activity)
 463         {
 464                 $owner = Contact::getIdForURL($activity['actor']);
 465
 466                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 467                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 468                 Queue::remove($activity);
 469         }
 470
 471         /**
 472          * Prepare the item array for an activity
 473          *
 474          * @param array $activity Activity array
 475          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 476          * @throws \ImagickException
 477          */
 478         public static function addTag(array $activity)
 479         {
 480                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 481                         return;
 482                 }
 483
 484                 foreach ($activity['receiver'] as $receiver) {
 485                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 486                         if (!DBA::isResult($item)) {
 487                                 // We don't fetch missing content for this purpose
 488                                 continue;
 489                         }
 490
 491                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 492                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 493                                 continue;
 494                         }
 495
 496                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 497                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 498                 }
 499         }
 500
 501         /**
 502          * Prepare the item array for an activity
 503          *
 504          * @param array      $activity   Activity array
 505          * @param string     $verb       Activity verb
 506          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 507          * @throws \ImagickException
 508          */
 509         public static function createActivity(array $activity, string $verb)
 510         {
 511                 $activity['reply-to-id'] = $activity['object_id'];
 512                 $item = self::createItem($activity);
 513                 if (empty($item)) {
 514                         return;
 515                 }
 516
 517                 $item['verb'] = $verb;
 518                 $item['thr-parent'] = $activity['object_id'];
 519                 $item['gravity'] = GRAVITY_ACTIVITY;
 520                 unset($item['post-type']);
 521                 $item['object-type'] = Activity\ObjectType::NOTE;
 522
 523                 if (!empty($activity['content'])) {
 524                         $item['body'] = HTML::toBBCode($activity['content']);
 525                 }
 526
 527                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 528
 529                 self::postItem($activity, $item);
 530         }
 531
 532         /**
 533          * Fetch the Uri-Id of a post for the "featured" collection
 534          *
 535          * @param array $activity
 536          * @return null|int
 537          */
 538         private static function getUriIdForFeaturedCollection(array $activity)
 539         {
 540                 $actor = APContact::getByURL($activity['actor']);
 541                 if (empty($actor)) {
 542                         return null;
 543                 }
 544
 545                 // Refetch the account when the "featured" collection is missing.
 546                 // This can be removed in a future version (end of 2022 should be good).
 547                 if (empty($actor['featured'])) {
 548                         $actor = APContact::getByURL($activity['actor'], true);
 549                         if (empty($actor)) {
 550                                 return null;
 551                         }
 552                 }
 553
 554                 if ($activity['target_id'] != $actor['featured']) {
 555                         return null;
 556                 }
 557
 558                 $id = Contact::getIdForURL($activity['actor']);
 559                 if (empty($id)) {
 560                         return null;
 561                 }
 562
 563                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id'], 'author-id' => $id]);
 564                 if (!empty($parent['uri-id'])) {
 565                         return $parent['uri-id'];
 566                 }
 567
 568                 return null;
 569         }
 570
 571         /**
 572          * Add a post to the "Featured" collection
 573          *
 574          * @param array $activity
 575          */
 576         public static function addToFeaturedCollection(array $activity)
 577         {
 578                 $uriid = self::getUriIdForFeaturedCollection($activity);
 579                 if (empty($uriid)) {
 580                         return;
 581                 }
 582
 583                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 584
 585                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 586                 Queue::remove($activity);
 587         }
 588
 589         /**
 590          * Remove a post to the "Featured" collection
 591          *
 592          * @param array $activity
 593          */
 594         public static function removeFromFeaturedCollection(array $activity)
 595         {
 596                 $uriid = self::getUriIdForFeaturedCollection($activity);
 597                 if (empty($uriid)) {
 598                         return;
 599                 }
 600
 601                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 602
 603                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 604                 Queue::remove($activity);
 605         }
 606
 607         /**
 608          * Create an event
 609          *
 610          * @param array $activity Activity array
 611          * @param array $item
 612          *
 613          * @return int event id
 614          * @throws \Exception
 615          */
 616         public static function createEvent(array $activity, array $item): int
 617         {
 618                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 619                 $event['desc']      = HTML::toBBCode($activity['content']);
 620                 if (!empty($activity['start-time'])) {
 621                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 622                 }
 623                 if (!empty($activity['end-time'])) {
 624                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 625                 }
 626                 $event['nofinish']  = empty($event['finish']);
 627                 $event['location']  = $activity['location'];
 628                 $event['cid']       = $item['contact-id'];
 629                 $event['uid']       = $item['uid'];
 630                 $event['uri']       = $item['uri'];
 631                 $event['edited']    = $item['edited'];
 632                 $event['private']   = $item['private'];
 633                 $event['guid']      = $item['guid'];
 634                 $event['plink']     = $item['plink'];
 635                 $event['network']   = $item['network'];
 636                 $event['protocol']  = $item['protocol'];
 637                 $event['direction'] = $item['direction'];
 638                 $event['source']    = $item['source'];
 639
 640                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 641                 if (DBA::isResult($ev)) {
 642                         $event['id'] = $ev['id'];
 643                 }
 644
 645                 $event_id = Event::store($event);
 646
 647                 Logger::info('Event was stored', ['id' => $event_id]);
 648
 649                 return $event_id;
 650         }
 651
 652         /**
 653          * Process the content
 654          *
 655          * @param array $activity Activity array
 656          * @param array $item
 657          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 658          * @throws \Exception
 659          */
 660         private static function processContent(array $activity, array $item)
 661         {
 662                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 663                         $item['title'] = strip_tags($activity['name']);
 664                         $content = Markdown::toBBCode($activity['content']);
 665                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 666                         $item['title'] = $activity['name'];
 667                         $content = $activity['content'];
 668                 } else {
 669                         // By default assume "text/html"
 670                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 671                         $content = HTML::toBBCode($activity['content'] ?? '');
 672                 }
 673
 674                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 675
 676                 if (!empty($activity['languages'])) {
 677                         $item['language'] = self::processLanguages($activity['languages']);
 678                 }
 679
 680                 if (!empty($activity['emojis'])) {
 681                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 682                 }
 683
 684                 $content = self::addMentionLinks($content, $activity['tags']);
 685
 686                 if (!empty($activity['source'])) {
 687                         $item['body'] = $activity['source'];
 688                         $item['raw-body'] = $content;
 689                         $item['body'] = Item::improveSharedDataInBody($item);
 690                 } else {
 691                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 692                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 693                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 694                                 if (!DBA::isResult($parent)) {
 695                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 696                                         return false;
 697                                 }
 698                                 if (($item['private'] == Item::PRIVATE) && ($parent['private'] != Item::PRIVATE)) {
 699                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 700                                         return false;
 701                                 }
 702
 703                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 704                         }
 705                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 706                         $item['raw-body'] = $item['body'] = $content;
 707                 }
 708
 709                 self::storeFromBody($item);
 710                 self::storeTags($item['uri-id'], $activity['tags']);
 711
 712                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 713
 714                 $item['location'] = $activity['location'];
 715
 716                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 717                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 718                 }
 719
 720                 $item['app'] = $activity['generator'];
 721
 722                 return $item;
 723         }
 724
 725         /**
 726          * Store hashtags and mentions
 727          *
 728          * @param array $item
 729          */
 730         private static function storeFromBody(array $item)
 731         {
 732                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 733                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 734
 735                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 736         }
 737
 738         /**
 739          * Generate a GUID out of an URL of an ActivityPub post.
 740          *
 741          * @param string $url message URL
 742          * @return string with GUID
 743          */
 744         private static function getGUIDByURL(string $url): string
 745         {
 746                 $parsed = parse_url($url);
 747
 748                 $host_hash = hash('crc32', $parsed['host']);
 749
 750                 unset($parsed["scheme"]);
 751                 unset($parsed["host"]);
 752
 753                 $path = implode("/", $parsed);
 754
 755                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 756         }
 757
 758         /**
 759          * Checks if an incoming message is wanted
 760          *
 761          * @param array $activity
 762          * @param array $item
 763          * @return boolean Is the message wanted?
 764          */
 765         private static function isSolicitedMessage(array $activity, array $item): bool
 766         {
 767                 // The checks are split to improve the support when searching why a message was accepted.
 768                 if (count($activity['receiver']) != 1) {
 769                         // The message has more than one receiver, so it is wanted.
 770                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 771                         return true;
 772                 }
 773
 774                 if ($item['private'] == Item::PRIVATE) {
 775                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 776                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 777                         return true;
 778                 }
 779
 780                 if (!empty($activity['from-relay'])) {
 781                         // We check relay posts at another place. When it arrived here, the message is already checked.
 782                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 783                         return true;
 784                 }
 785
 786                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 787                         // Manual completions and completions caused by reshares are allowed without any further checks.
 788                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 789                         return true;
 790                 }
 791
 792                 if ($item['gravity'] != GRAVITY_PARENT) {
 793                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 794                         // This can possibly be improved in the future.
 795                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 796                         return true;
 797                 }
 798
 799                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 800                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 801                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 802                         return true;
 803                 } else {
 804                         return false;
 805                 }
 806         }
 807
 808         /**
 809          * Creates an item post
 810          *
 811          * @param array $activity Activity data
 812          * @param array $item     item array
 813          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 814          * @throws \ImagickException
 815          */
 816         public static function postItem(array $activity, array $item)
 817         {
 818                 if (empty($item)) {
 819                         return;
 820                 }
 821
 822                 $stored = false;
 823                 $success = false;
 824                 ksort($activity['receiver']);
 825
 826                 if (!self::isSolicitedMessage($activity, $item)) {
 827                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 828                         return;
 829                 }
 830
 831                 foreach ($activity['receiver'] as $receiver) {
 832                         if ($receiver == -1) {
 833                                 continue;
 834                         }
 835
 836                         $item['uid'] = $receiver;
 837
 838                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 839                         switch($type) {
 840                                 case Receiver::TARGET_TO:
 841                                         $item['post-reason'] = Item::PR_TO;
 842                                         break;
 843                                 case Receiver::TARGET_CC:
 844                                         $item['post-reason'] = Item::PR_CC;
 845                                         break;
 846                                 case Receiver::TARGET_BTO:
 847                                         $item['post-reason'] = Item::PR_BTO;
 848                                         break;
 849                                 case Receiver::TARGET_BCC:
 850                                         $item['post-reason'] = Item::PR_BCC;
 851                                         break;
 852                                 case Receiver::TARGET_FOLLOWER:
 853                                         $item['post-reason'] = Item::PR_FOLLOWER;
 854                                         break;
 855                                 case Receiver::TARGET_ANSWER:
 856                                         $item['post-reason'] = Item::PR_COMMENT;
 857                                         break;
 858                                 case Receiver::TARGET_GLOBAL:
 859                                         $item['post-reason'] = Item::PR_GLOBAL;
 860                                         break;
 861                                 default:
 862                                         $item['post-reason'] = Item::PR_NONE;
 863                         }
 864
 865                         if (!empty($activity['from-relay'])) {
 866                                 $item['post-reason'] = Item::PR_RELAY;
 867                         } elseif (!empty($activity['thread-completion'])) {
 868                                 $item['post-reason'] = Item::PR_FETCHED;
 869                         }
 870
 871                         if ($item['isForum'] ?? false) {
 872                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 873                         } else {
 874                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 875                         }
 876
 877                         if (($receiver != 0) && empty($item['contact-id'])) {
 878                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 879                         }
 880
 881                         if (!empty($activity['directmessage'])) {
 882                                 self::postMail($activity, $item);
 883                                 continue;
 884                         }
 885
 886                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 887                                 if ($item['post-reason'] == Item::PR_BCC) {
 888                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 889                                         continue;
 890                                 }
 891
 892                                 if (
 893                                         !empty($activity['thread-children-type'])
 894                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 895                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 896                                 ) {
 897                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 898                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 899                                         continue;
 900                                 }
 901                         }
 902
 903                         $is_forum = false;
 904
 905                         if ($receiver != 0) {
 906                                 $user = User::getById($receiver, ['account-type']);
 907                                 if (!empty($user['account-type'])) {
 908                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 909                                 }
 910                         }
 911
 912                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 913                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 914
 915                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 916                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 917                                 }
 918
 919                                 if ($skip) {
 920                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 921                                         continue;
 922                                 }
 923
 924                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 925                         }
 926
 927                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 928                                 $event_id = self::createEvent($activity, $item);
 929
 930                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 931                         }
 932
 933                         $item_id = Item::insert($item);
 934                         if ($item_id) {
 935                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 936                                 $success = true;
 937                         } else {
 938                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 939                         }
 940
 941                         if ($item['uid'] == 0) {
 942                                 $stored = $item_id;
 943                         }
 944                 }
 945
 946                 if ($success) {
 947                         Queue::remove($activity);
 948                         Queue::processReplyByUri($item['uri']);
 949                 }
 950
 951                 // Store send a follow request for every reshare - but only when the item had been stored
 952                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
 953                         $author = APContact::getByURL($item['owner-link'], false);
 954                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 955                         if ($author['type'] != 'Group') {
 956                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 957                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 958                         }
 959                 }
 960         }
 961
 962         /**
 963          * Store tags and mentions into the tag table
 964          *
 965          * @param integer $uriid
 966          * @param array $tags
 967          */
 968         private static function storeTags(int $uriid, array $tags = null)
 969         {
 970                 foreach ($tags as $tag) {
 971                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 972                                 continue;
 973                         }
 974
 975                         $hash = substr($tag['name'], 0, 1);
 976
 977                         if ($tag['type'] == 'Mention') {
 978                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 979                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 980                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 981                                         $tag['name'] = substr($tag['name'], 1);
 982                                 }
 983                                 $type = Tag::IMPLICIT_MENTION;
 984
 985                                 if (!empty($tag['href'])) {
 986                                         $apcontact = APContact::getByURL($tag['href']);
 987                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 988                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 989                                         }
 990                                 }
 991                         } elseif ($tag['type'] == 'Hashtag') {
 992                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 993                                         $tag['name'] = substr($tag['name'], 1);
 994                                 }
 995                                 $type = Tag::HASHTAG;
 996                         }
 997
 998                         if (empty($tag['name'])) {
 999                                 continue;
1000                         }
1001
1002                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1003                 }
1004         }
1005
1006         public static function storeReceivers(int $uriid, array $receivers)
1007         {
1008                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
1009                         if (!empty($receivers[$element])) {
1010                                 foreach ($receivers[$element] as $receiver) {
1011                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1012                                                 $name = Receiver::PUBLIC_COLLECTION;
1013                                         } else {
1014                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
1015                                         }
1016
1017                                         $target = Tag::getTargetType($receiver);
1018                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1019                                         Tag::store($uriid, $type, $name, $receiver, $target);
1020                                 }
1021                         }
1022                 }
1023         }
1024
1025         /**
1026          * Creates an mail post
1027          *
1028          * @param array $activity Activity data
1029          * @param array $item     item array
1030          * @return int|bool New mail table row id or false on error
1031          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1032          */
1033         private static function postMail(array $activity, array $item)
1034         {
1035                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1036                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1037                         return false;
1038                 }
1039
1040                 Logger::info('Direct Message', $item);
1041
1042                 $msg = [];
1043                 $msg['uid'] = $item['uid'];
1044
1045                 $msg['contact-id'] = $item['contact-id'];
1046
1047                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1048                 $msg['from-name'] = $contact['name'];
1049                 $msg['from-url'] = $contact['url'];
1050                 $msg['from-photo'] = $contact['photo'];
1051
1052                 $msg['uri'] = $item['uri'];
1053                 $msg['created'] = $item['created'];
1054
1055                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1056                 if (DBA::isResult($parent)) {
1057                         $msg['parent-uri'] = $parent['parent-uri'];
1058                         $msg['title'] = $parent['title'];
1059                 } else {
1060                         $msg['parent-uri'] = $item['thr-parent'];
1061
1062                         if (!empty($item['title'])) {
1063                                 $msg['title'] = $item['title'];
1064                         } elseif (!empty($item['content-warning'])) {
1065                                 $msg['title'] = $item['content-warning'];
1066                         } else {
1067                                 // Trying to generate a title out of the body
1068                                 $title = $item['body'];
1069
1070                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1071                                         $title = $matches[3];
1072                                 }
1073
1074                                 $title = trim(BBCode::toPlaintext($title));
1075
1076                                 if (strlen($title) > 20) {
1077                                         $title = substr($title, 0, 20) . '...';
1078                                 }
1079
1080                                 $msg['title'] = $title;
1081                         }
1082                 }
1083                 $msg['body'] = $item['body'];
1084
1085                 return Mail::insert($msg);
1086         }
1087
1088         /**
1089          * Fetch featured posts from a contact with the given url
1090          *
1091          * @param string $url
1092          * @return void
1093          */
1094         public static function fetchFeaturedPosts(string $url)
1095         {
1096                 Logger::info('Fetch featured posts', ['contact' => $url]);
1097
1098                 $apcontact = APContact::getByURL($url);
1099                 if (empty($apcontact['featured'])) {
1100                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1101                         return;
1102                 }
1103
1104                 $pcid = Contact::getIdForURL($url, 0, false);
1105                 if (empty($pcid)) {
1106                         Logger::info('Contact not found', ['contact' => $url]);
1107                         return;
1108                 }
1109
1110                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1111                 if (!empty($posts)) {
1112                         $old_featured = array_column($posts, 'uri-id');
1113                 } else {
1114                         $old_featured = [];
1115                 }
1116
1117                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1118                 if (empty($featured)) {
1119                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1120
1121                         foreach ($old_featured as $uri_id) {
1122                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1123                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1124                         }
1125                         return;
1126                 }
1127
1128                 $new = 0;
1129                 $old = 0;
1130
1131                 foreach ($featured as $post) {
1132                         if (empty($post['id'])) {
1133                                 continue;
1134                         }
1135                         $id = Item::fetchByLink($post['id']);
1136                         if (!empty($id)) {
1137                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1138                                 if (!empty($item['uri-id'])) {
1139                                         if (!$item['featured']) {
1140                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1141                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1142                                                 $new++;
1143                                         } else {
1144                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1145                                                 $old++;
1146                                         }
1147
1148                                         $index = array_search($item['uri-id'], $old_featured);
1149                                         if (!($index === false)) {
1150                                                 unset($old_featured[$index]);
1151                                         }
1152                                 }
1153                         }
1154                 }
1155
1156                 foreach ($old_featured as $uri_id) {
1157                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1158                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1159                 }
1160
1161                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1162         }
1163
1164         /**
1165          * Fetches missing posts
1166          *
1167          * @param string     $url         message URL
1168          * @param array      $child       activity array with the child of this message
1169          * @param string     $relay_actor Relay actor
1170          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1171          * @return string fetched message URL
1172          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1173          * @throws \ImagickException
1174          */
1175         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL): string
1176         {
1177                 if (!empty($child['receiver'])) {
1178                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1179                 } else {
1180                         $uid = 0;
1181                 }
1182
1183                 $object = ActivityPub::fetchContent($url, $uid);
1184                 if (empty($object)) {
1185                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1186                         return '';
1187                 }
1188
1189                 if (empty($object['id'])) {
1190                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1191                         return '';
1192                 }
1193
1194                 if (!empty($object['actor'])) {
1195                         $object_actor = $object['actor'];
1196                 } elseif (!empty($object['attributedTo'])) {
1197                         $object_actor = $object['attributedTo'];
1198                         if (is_array($object_actor)) {
1199                                 $compacted = JsonLD::compact($object);
1200                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1201                         }
1202                 } else {
1203                         // Shouldn't happen
1204                         $object_actor = '';
1205                 }
1206
1207                 $signer = [$object_actor];
1208
1209                 if (!empty($child['author'])) {
1210                         $actor = $child['author'];
1211                         $signer[] = $actor;
1212                 } else {
1213                         $actor = $object_actor;
1214                 }
1215
1216                 if (!empty($object['published'])) {
1217                         $published = $object['published'];
1218                 } elseif (!empty($child['published'])) {
1219                         $published = $child['published'];
1220                 } else {
1221                         $published = DateTimeFormat::utcNow();
1222                 }
1223
1224                 $activity = [];
1225                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1226                 unset($object['@context']);
1227                 $activity['id'] = $object['id'];
1228                 $activity['to'] = $object['to'] ?? [];
1229                 $activity['cc'] = $object['cc'] ?? [];
1230                 $activity['actor'] = $actor;
1231                 $activity['object'] = $object;
1232                 $activity['published'] = $published;
1233                 $activity['type'] = 'Create';
1234
1235                 $ldactivity = JsonLD::compact($activity);
1236
1237                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 1;
1238
1239                 if (!empty($relay_actor)) {
1240                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1241                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1242                 } elseif (!empty($child['thread-completion'])) {
1243                         $ldactivity['thread-completion'] = $child['thread-completion'];
1244                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1245                 } else {
1246                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1247                         $ldactivity['completion-mode']   = $completion;
1248                 }
1249
1250                 if (!empty($child['type'])) {
1251                         $ldactivity['thread-children-type'] = $child['type'];
1252                 }
1253
1254                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1255                         return '';
1256                 }
1257
1258                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1259
1260                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1261
1262                 return $activity['id'];
1263         }
1264
1265         /**
1266          * Test if incoming relay messages should be accepted
1267          *
1268          * @param array $activity activity array
1269          * @param string $id      object ID
1270          * @return boolean true if message is accepted
1271          */
1272         private static function acceptIncomingMessage(array $activity, string $id): bool
1273         {
1274                 if (empty($activity['as:object'])) {
1275                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1276                         return true;
1277                 }
1278
1279                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1280                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1281                 if (Post::exists(['uri-id' => $uriid])) {
1282                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1283                         return true;
1284                 }
1285
1286                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1287                 $authorid = Contact::getIdForURL($attributed_to);
1288
1289                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1290
1291                 $messageTags = [];
1292                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1293                 if (!empty($tags)) {
1294                         foreach ($tags as $tag) {
1295                                 if ($tag['type'] != 'Hashtag') {
1296                                         continue;
1297                                 }
1298                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1299                         }
1300                 }
1301
1302                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1303         }
1304
1305         /**
1306          * perform a "follow" request
1307          *
1308          * @param array $activity
1309          * @return void
1310          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1311          * @throws \ImagickException
1312          */
1313         public static function followUser(array $activity)
1314         {
1315                 $uid = User::getIdForURL($activity['object_id']);
1316                 if (empty($uid)) {
1317                         return;
1318                 }
1319
1320                 $owner = User::getOwnerDataById($uid);
1321                 if (empty($owner)) {
1322                         return;
1323                 }
1324
1325                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1326                 if (!empty($cid)) {
1327                         self::switchContact($cid);
1328                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1329                 }
1330
1331                 $item = [
1332                         'author-id' => Contact::getIdForURL($activity['actor']),
1333                         'author-link' => $activity['actor'],
1334                 ];
1335
1336                 // Ensure that the contact has got the right network type
1337                 self::switchContact($item['author-id']);
1338
1339                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1340                 if ($result === true) {
1341                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1342                 }
1343
1344                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1345                 if (empty($cid)) {
1346                         return;
1347                 }
1348
1349                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1350                         self::transmitPendingEvents($cid, $owner['uid']);
1351                 }
1352
1353                 if (empty($contact)) {
1354                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1355                 }
1356                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1357                 Queue::remove($activity);
1358         }
1359
1360         /**
1361          * Transmit pending events to the new follower
1362          *
1363          * @param integer $cid Contact id
1364          * @param integer $uid User id
1365          * @return void
1366          */
1367         private static function transmitPendingEvents(int $cid, int $uid)
1368         {
1369                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1370                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1371
1372                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1373                 while ($event = DBA::fetch($events)) {
1374                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1375                         if (empty($post)) {
1376                                 continue;
1377                         }
1378                         if (DI::config()->get('system', 'bulk_delivery')) {
1379                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1380                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1381                         } else {
1382                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1383                         }
1384                 }
1385         }
1386
1387         /**
1388          * Update the given profile
1389          *
1390          * @param array $activity
1391          * @throws \Exception
1392          */
1393         public static function updatePerson(array $activity)
1394         {
1395                 if (empty($activity['object_id'])) {
1396                         return;
1397                 }
1398
1399                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1400                 Contact::updateFromProbeByURL($activity['object_id']);
1401                 Queue::remove($activity);
1402         }
1403
1404         /**
1405          * Delete the given profile
1406          *
1407          * @param array $activity
1408          * @return void
1409          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1410          */
1411         public static function deletePerson(array $activity)
1412         {
1413                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1414                         Logger::info('Empty object id or actor.');
1415                         return;
1416                 }
1417
1418                 if ($activity['object_id'] != $activity['actor']) {
1419                         Logger::info('Object id does not match actor.');
1420                         return;
1421                 }
1422
1423                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1424                 while ($contact = DBA::fetch($contacts)) {
1425                         Contact::remove($contact['id']);
1426                 }
1427                 DBA::close($contacts);
1428
1429                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1430                 Queue::remove($activity);
1431         }
1432
1433         /**
1434          * Blocks the user by the contact
1435          *
1436          * @param array $activity
1437          * @return void
1438          * @throws \Exception
1439          */
1440         public static function blockAccount(array $activity)
1441         {
1442                 $cid = Contact::getIdForURL($activity['actor']);
1443                 if (empty($cid)) {
1444                         return;
1445                 }
1446
1447                 $uid = User::getIdForURL($activity['object_id']);
1448                 if (empty($uid)) {
1449                         return;
1450                 }
1451
1452                 Contact\User::setIsBlocked($cid, $uid, true);
1453
1454                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1455                 Queue::remove($activity);
1456         }
1457
1458         /**
1459          * Unblocks the user by the contact
1460          *
1461          * @param array $activity
1462          * @return void
1463          * @throws \Exception
1464          */
1465         public static function unblockAccount(array $activity)
1466         {
1467                 $cid = Contact::getIdForURL($activity['actor']);
1468                 if (empty($cid)) {
1469                         return;
1470                 }
1471
1472                 $uid = User::getIdForURL($activity['object_object']);
1473                 if (empty($uid)) {
1474                         return;
1475                 }
1476
1477                 Contact\User::setIsBlocked($cid, $uid, false);
1478
1479                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1480                 Queue::remove($activity);
1481         }
1482
1483         /**
1484          * Accept a follow request
1485          *
1486          * @param array $activity
1487          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1488          * @throws \ImagickException
1489          */
1490         public static function acceptFollowUser(array $activity)
1491         {
1492                 $uid = User::getIdForURL($activity['object_actor']);
1493                 if (empty($uid)) {
1494                         return;
1495                 }
1496
1497                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1498                 if (empty($cid)) {
1499                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1500                         return;
1501                 }
1502
1503                 self::switchContact($cid);
1504
1505                 $fields = ['pending' => false];
1506
1507                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1508                 if ($contact['rel'] == Contact::FOLLOWER) {
1509                         $fields['rel'] = Contact::FRIEND;
1510                 }
1511
1512                 $condition = ['id' => $cid];
1513                 Contact::update($fields, $condition);
1514                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1515                 Queue::remove($activity);
1516         }
1517
1518         /**
1519          * Reject a follow request
1520          *
1521          * @param array $activity
1522          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1523          * @throws \ImagickException
1524          */
1525         public static function rejectFollowUser(array $activity)
1526         {
1527                 $uid = User::getIdForURL($activity['object_actor']);
1528                 if (empty($uid)) {
1529                         return;
1530                 }
1531
1532                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1533                 if (empty($cid)) {
1534                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1535                         return;
1536                 }
1537
1538                 self::switchContact($cid);
1539
1540                 $contact = Contact::getById($cid, ['rel']);
1541                 if ($contact['rel'] == Contact::SHARING) {
1542                         Contact::remove($cid);
1543                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1544                 } elseif ($contact['rel'] == Contact::FRIEND) {
1545                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1546                 } else {
1547                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1548                 }
1549                 Queue::remove($activity);
1550         }
1551
1552         /**
1553          * Undo activity like "like" or "dislike"
1554          *
1555          * @param array $activity
1556          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1557          * @throws \ImagickException
1558          */
1559         public static function undoActivity(array $activity)
1560         {
1561                 if (empty($activity['object_id'])) {
1562                         return;
1563                 }
1564
1565                 if (empty($activity['object_actor'])) {
1566                         return;
1567                 }
1568
1569                 $author_id = Contact::getIdForURL($activity['object_actor']);
1570                 if (empty($author_id)) {
1571                         return;
1572                 }
1573
1574                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1575                 Queue::remove($activity);
1576         }
1577
1578         /**
1579          * Activity to remove a follower
1580          *
1581          * @param array $activity
1582          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1583          * @throws \ImagickException
1584          */
1585         public static function undoFollowUser(array $activity)
1586         {
1587                 $uid = User::getIdForURL($activity['object_object']);
1588                 if (empty($uid)) {
1589                         return;
1590                 }
1591
1592                 $owner = User::getOwnerDataById($uid);
1593                 if (empty($owner)) {
1594                         return;
1595                 }
1596
1597                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1598                 if (empty($cid)) {
1599                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1600                         return;
1601                 }
1602
1603                 self::switchContact($cid);
1604
1605                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1606                 if (!DBA::isResult($contact)) {
1607                         return;
1608                 }
1609
1610                 Contact::removeFollower($contact);
1611                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1612                 Queue::remove($activity);
1613         }
1614
1615         /**
1616          * Switches a contact to AP if needed
1617          *
1618          * @param integer $cid Contact ID
1619          * @return void
1620          * @throws \Exception
1621          */
1622         private static function switchContact(int $cid)
1623         {
1624                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1625                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1626                         return;
1627                 }
1628
1629                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1630                 Contact::updateFromProbe($cid);
1631         }
1632
1633         /**
1634          * Collects implicit mentions like:
1635          * - the author of the parent item
1636          * - all the mentioned conversants in the parent item
1637          *
1638          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1639          * @return array
1640          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1641          */
1642         private static function getImplicitMentionList(array $parent): array
1643         {
1644                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1645
1646                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1647
1648                 $implicit_mentions = [];
1649                 if (empty($parent_author['url'])) {
1650                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1651                 } else {
1652                         $implicit_mentions[] = $parent_author['url'];
1653                         $implicit_mentions[] = $parent_author['nurl'];
1654                         $implicit_mentions[] = $parent_author['alias'];
1655                 }
1656
1657                 if (!empty($parent['alias'])) {
1658                         $implicit_mentions[] = $parent['alias'];
1659                 }
1660
1661                 foreach ($parent_terms as $term) {
1662                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1663                         if (!empty($contact['url'])) {
1664                                 $implicit_mentions[] = $contact['url'];
1665                                 $implicit_mentions[] = $contact['nurl'];
1666                                 $implicit_mentions[] = $contact['alias'];
1667                         }
1668                 }
1669
1670                 return $implicit_mentions;
1671         }
1672
1673         /**
1674          * Strips from the body prepended implicit mentions
1675          *
1676          * @param string $body
1677          * @param array $parent
1678          * @return string
1679          */
1680         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
1681         {
1682                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1683                         return $body;
1684                 }
1685
1686                 $potential_mentions = self::getImplicitMentionList($parent);
1687
1688                 $kept_mentions = [];
1689
1690                 // Extract one prepended mention at a time from the body
1691                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1692                         if (!in_array($matches[2], $potential_mentions)) {
1693                                 $kept_mentions[] = $matches[1];
1694                         }
1695
1696                         $body = $matches[3];
1697                 }
1698
1699                 // Re-appending the kept mentions to the body after extraction
1700                 $kept_mentions[] = $body;
1701
1702                 return implode('', $kept_mentions);
1703         }
1704
1705         /**
1706          * Adds links to string mentions
1707          *
1708          * @param string $body
1709          * @param array  $tags
1710          * @return string
1711          */
1712         protected static function addMentionLinks(string $body, array $tags): string
1713         {
1714                 // This prevents links to be added again to Pleroma-style mention links
1715                 $body = self::normalizeMentionLinks($body);
1716
1717                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1718                         foreach ($tags as $tag) {
1719                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1720                                         continue;
1721                                 }
1722
1723                                 $hash = substr($tag['name'], 0, 1);
1724                                 $name = substr($tag['name'], 1);
1725                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1726                                         $hash = '';
1727                                         $name = $tag['name'];
1728                                 }
1729
1730                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1731                         }
1732
1733                         return $body;
1734                 });
1735
1736                 return $body;
1737         }
1738 }