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                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 555                 if (empty($parent['uri-id'])) {
 556                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 557                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 558                         }
 559                 }
 560
 561                 if (!empty($parent['uri-id'])) {
 562                         return $parent['uri-id'];
 563                 }
 564
 565                 return null;
 566         }
 567
 568         /**
 569          * Add a post to the "Featured" collection
 570          *
 571          * @param array $activity
 572          */
 573         public static function addToFeaturedCollection(array $activity)
 574         {
 575                 $uriid = self::getUriIdForFeaturedCollection($activity);
 576                 if (empty($uriid)) {
 577                         return;
 578                 }
 579
 580                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 581
 582                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 583                 Queue::remove($activity);
 584         }
 585
 586         /**
 587          * Remove a post to the "Featured" collection
 588          *
 589          * @param array $activity
 590          */
 591         public static function removeFromFeaturedCollection(array $activity)
 592         {
 593                 $uriid = self::getUriIdForFeaturedCollection($activity);
 594                 if (empty($uriid)) {
 595                         return;
 596                 }
 597
 598                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 599
 600                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 601                 Queue::remove($activity);
 602         }
 603
 604         /**
 605          * Create an event
 606          *
 607          * @param array $activity Activity array
 608          * @param array $item
 609          *
 610          * @return int event id
 611          * @throws \Exception
 612          */
 613         public static function createEvent(array $activity, array $item): int
 614         {
 615                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 616                 $event['desc']      = HTML::toBBCode($activity['content']);
 617                 if (!empty($activity['start-time'])) {
 618                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 619                 }
 620                 if (!empty($activity['end-time'])) {
 621                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 622                 }
 623                 $event['nofinish']  = empty($event['finish']);
 624                 $event['location']  = $activity['location'];
 625                 $event['cid']       = $item['contact-id'];
 626                 $event['uid']       = $item['uid'];
 627                 $event['uri']       = $item['uri'];
 628                 $event['edited']    = $item['edited'];
 629                 $event['private']   = $item['private'];
 630                 $event['guid']      = $item['guid'];
 631                 $event['plink']     = $item['plink'];
 632                 $event['network']   = $item['network'];
 633                 $event['protocol']  = $item['protocol'];
 634                 $event['direction'] = $item['direction'];
 635                 $event['source']    = $item['source'];
 636
 637                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 638                 if (DBA::isResult($ev)) {
 639                         $event['id'] = $ev['id'];
 640                 }
 641
 642                 $event_id = Event::store($event);
 643
 644                 Logger::info('Event was stored', ['id' => $event_id]);
 645
 646                 return $event_id;
 647         }
 648
 649         /**
 650          * Process the content
 651          *
 652          * @param array $activity Activity array
 653          * @param array $item
 654          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 655          * @throws \Exception
 656          */
 657         private static function processContent(array $activity, array $item)
 658         {
 659                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 660                         $item['title'] = strip_tags($activity['name']);
 661                         $content = Markdown::toBBCode($activity['content']);
 662                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 663                         $item['title'] = $activity['name'];
 664                         $content = $activity['content'];
 665                 } else {
 666                         // By default assume "text/html"
 667                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 668                         $content = HTML::toBBCode($activity['content'] ?? '');
 669                 }
 670
 671                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 672
 673                 if (!empty($activity['languages'])) {
 674                         $item['language'] = self::processLanguages($activity['languages']);
 675                 }
 676
 677                 if (!empty($activity['emojis'])) {
 678                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 679                 }
 680
 681                 $content = self::addMentionLinks($content, $activity['tags']);
 682
 683                 if (!empty($activity['source'])) {
 684                         $item['body'] = $activity['source'];
 685                         $item['raw-body'] = $content;
 686                         $item['body'] = Item::improveSharedDataInBody($item);
 687                 } else {
 688                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 689                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 690                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 691                                 if (!DBA::isResult($parent)) {
 692                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 693                                         return false;
 694                                 }
 695                                 if (($item['private'] == Item::PRIVATE) && ($parent['private'] != Item::PRIVATE)) {
 696                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 697                                         return false;
 698                                 }
 699
 700                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 701                         }
 702                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 703                         $item['raw-body'] = $item['body'] = $content;
 704                 }
 705
 706                 self::storeFromBody($item);
 707                 self::storeTags($item['uri-id'], $activity['tags']);
 708
 709                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 710
 711                 $item['location'] = $activity['location'];
 712
 713                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 714                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 715                 }
 716
 717                 $item['app'] = $activity['generator'];
 718
 719                 return $item;
 720         }
 721
 722         /**
 723          * Store hashtags and mentions
 724          *
 725          * @param array $item
 726          */
 727         private static function storeFromBody(array $item)
 728         {
 729                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 730                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 731
 732                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 733         }
 734
 735         /**
 736          * Generate a GUID out of an URL of an ActivityPub post.
 737          *
 738          * @param string $url message URL
 739          * @return string with GUID
 740          */
 741         private static function getGUIDByURL(string $url): string
 742         {
 743                 $parsed = parse_url($url);
 744
 745                 $host_hash = hash('crc32', $parsed['host']);
 746
 747                 unset($parsed["scheme"]);
 748                 unset($parsed["host"]);
 749
 750                 $path = implode("/", $parsed);
 751
 752                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 753         }
 754
 755         /**
 756          * Checks if an incoming message is wanted
 757          *
 758          * @param array $activity
 759          * @param array $item
 760          * @return boolean Is the message wanted?
 761          */
 762         private static function isSolicitedMessage(array $activity, array $item): bool
 763         {
 764                 // The checks are split to improve the support when searching why a message was accepted.
 765                 if (count($activity['receiver']) != 1) {
 766                         // The message has more than one receiver, so it is wanted.
 767                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 768                         return true;
 769                 }
 770
 771                 if ($item['private'] == Item::PRIVATE) {
 772                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 773                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 774                         return true;
 775                 }
 776
 777                 if (!empty($activity['from-relay'])) {
 778                         // We check relay posts at another place. When it arrived here, the message is already checked.
 779                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 780                         return true;
 781                 }
 782
 783                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 784                         // Manual completions and completions caused by reshares are allowed without any further checks.
 785                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 786                         return true;
 787                 }
 788
 789                 if ($item['gravity'] != GRAVITY_PARENT) {
 790                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 791                         // This can possibly be improved in the future.
 792                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 793                         return true;
 794                 }
 795
 796                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 797                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 798                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 799                         return true;
 800                 } else {
 801                         return false;
 802                 }
 803         }
 804
 805         /**
 806          * Creates an item post
 807          *
 808          * @param array $activity Activity data
 809          * @param array $item     item array
 810          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 811          * @throws \ImagickException
 812          */
 813         public static function postItem(array $activity, array $item)
 814         {
 815                 if (empty($item)) {
 816                         return;
 817                 }
 818
 819                 $stored = false;
 820                 $success = false;
 821                 ksort($activity['receiver']);
 822
 823                 if (!self::isSolicitedMessage($activity, $item)) {
 824                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 825                         return;
 826                 }
 827
 828                 foreach ($activity['receiver'] as $receiver) {
 829                         if ($receiver == -1) {
 830                                 continue;
 831                         }
 832
 833                         $item['uid'] = $receiver;
 834
 835                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 836                         switch($type) {
 837                                 case Receiver::TARGET_TO:
 838                                         $item['post-reason'] = Item::PR_TO;
 839                                         break;
 840                                 case Receiver::TARGET_CC:
 841                                         $item['post-reason'] = Item::PR_CC;
 842                                         break;
 843                                 case Receiver::TARGET_BTO:
 844                                         $item['post-reason'] = Item::PR_BTO;
 845                                         break;
 846                                 case Receiver::TARGET_BCC:
 847                                         $item['post-reason'] = Item::PR_BCC;
 848                                         break;
 849                                 case Receiver::TARGET_FOLLOWER:
 850                                         $item['post-reason'] = Item::PR_FOLLOWER;
 851                                         break;
 852                                 case Receiver::TARGET_ANSWER:
 853                                         $item['post-reason'] = Item::PR_COMMENT;
 854                                         break;
 855                                 case Receiver::TARGET_GLOBAL:
 856                                         $item['post-reason'] = Item::PR_GLOBAL;
 857                                         break;
 858                                 default:
 859                                         $item['post-reason'] = Item::PR_NONE;
 860                         }
 861
 862                         if (!empty($activity['from-relay'])) {
 863                                 $item['post-reason'] = Item::PR_RELAY;
 864                         } elseif (!empty($activity['thread-completion'])) {
 865                                 $item['post-reason'] = Item::PR_FETCHED;
 866                         }
 867
 868                         if ($item['isForum'] ?? false) {
 869                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 870                         } else {
 871                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 872                         }
 873
 874                         if (($receiver != 0) && empty($item['contact-id'])) {
 875                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 876                         }
 877
 878                         if (!empty($activity['directmessage'])) {
 879                                 self::postMail($activity, $item);
 880                                 continue;
 881                         }
 882
 883                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 884                                 if ($item['post-reason'] == Item::PR_BCC) {
 885                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 886                                         continue;
 887                                 }
 888
 889                                 if (
 890                                         !empty($activity['thread-children-type'])
 891                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 892                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 893                                 ) {
 894                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 895                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 896                                         continue;
 897                                 }
 898                         }
 899
 900                         $is_forum = false;
 901
 902                         if ($receiver != 0) {
 903                                 $user = User::getById($receiver, ['account-type']);
 904                                 if (!empty($user['account-type'])) {
 905                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 906                                 }
 907                         }
 908
 909                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 910                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 911
 912                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 913                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 914                                 }
 915
 916                                 if ($skip) {
 917                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 918                                         continue;
 919                                 }
 920
 921                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 922                         }
 923
 924                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 925                                 $event_id = self::createEvent($activity, $item);
 926
 927                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 928                         }
 929
 930                         $item_id = Item::insert($item);
 931                         if ($item_id) {
 932                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 933                                 $success = true;
 934                         } else {
 935                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
 936                         }
 937
 938                         if ($item['uid'] == 0) {
 939                                 $stored = $item_id;
 940                         }
 941                 }
 942
 943                 if ($success) {
 944                         Queue::remove($activity);
 945                         Queue::processReplyByUri($item['uri']);
 946                 }
 947
 948                 // Store send a follow request for every reshare - but only when the item had been stored
 949                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
 950                         $author = APContact::getByURL($item['owner-link'], false);
 951                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 952                         if ($author['type'] != 'Group') {
 953                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 954                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 955                         }
 956                 }
 957         }
 958
 959         /**
 960          * Store tags and mentions into the tag table
 961          *
 962          * @param integer $uriid
 963          * @param array $tags
 964          */
 965         private static function storeTags(int $uriid, array $tags = null)
 966         {
 967                 foreach ($tags as $tag) {
 968                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 969                                 continue;
 970                         }
 971
 972                         $hash = substr($tag['name'], 0, 1);
 973
 974                         if ($tag['type'] == 'Mention') {
 975                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 976                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 977                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 978                                         $tag['name'] = substr($tag['name'], 1);
 979                                 }
 980                                 $type = Tag::IMPLICIT_MENTION;
 981
 982                                 if (!empty($tag['href'])) {
 983                                         $apcontact = APContact::getByURL($tag['href']);
 984                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 985                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 986                                         }
 987                                 }
 988                         } elseif ($tag['type'] == 'Hashtag') {
 989                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 990                                         $tag['name'] = substr($tag['name'], 1);
 991                                 }
 992                                 $type = Tag::HASHTAG;
 993                         }
 994
 995                         if (empty($tag['name'])) {
 996                                 continue;
 997                         }
 998
 999                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1000                 }
1001         }
1002
1003         public static function storeReceivers(int $uriid, array $receivers)
1004         {
1005                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
1006                         if (!empty($receivers[$element])) {
1007                                 foreach ($receivers[$element] as $receiver) {
1008                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1009                                                 $name = Receiver::PUBLIC_COLLECTION;
1010                                         } else {
1011                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
1012                                         }
1013
1014                                         $target = Tag::getTargetType($receiver);
1015                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1016                                         Tag::store($uriid, $type, $name, $receiver, $target);
1017                                 }
1018                         }
1019                 }
1020         }
1021
1022         /**
1023          * Creates an mail post
1024          *
1025          * @param array $activity Activity data
1026          * @param array $item     item array
1027          * @return int|bool New mail table row id or false on error
1028          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1029          */
1030         private static function postMail(array $activity, array $item)
1031         {
1032                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1033                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1034                         return false;
1035                 }
1036
1037                 Logger::info('Direct Message', $item);
1038
1039                 $msg = [];
1040                 $msg['uid'] = $item['uid'];
1041
1042                 $msg['contact-id'] = $item['contact-id'];
1043
1044                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1045                 $msg['from-name'] = $contact['name'];
1046                 $msg['from-url'] = $contact['url'];
1047                 $msg['from-photo'] = $contact['photo'];
1048
1049                 $msg['uri'] = $item['uri'];
1050                 $msg['created'] = $item['created'];
1051
1052                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1053                 if (DBA::isResult($parent)) {
1054                         $msg['parent-uri'] = $parent['parent-uri'];
1055                         $msg['title'] = $parent['title'];
1056                 } else {
1057                         $msg['parent-uri'] = $item['thr-parent'];
1058
1059                         if (!empty($item['title'])) {
1060                                 $msg['title'] = $item['title'];
1061                         } elseif (!empty($item['content-warning'])) {
1062                                 $msg['title'] = $item['content-warning'];
1063                         } else {
1064                                 // Trying to generate a title out of the body
1065                                 $title = $item['body'];
1066
1067                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1068                                         $title = $matches[3];
1069                                 }
1070
1071                                 $title = trim(BBCode::toPlaintext($title));
1072
1073                                 if (strlen($title) > 20) {
1074                                         $title = substr($title, 0, 20) . '...';
1075                                 }
1076
1077                                 $msg['title'] = $title;
1078                         }
1079                 }
1080                 $msg['body'] = $item['body'];
1081
1082                 return Mail::insert($msg);
1083         }
1084
1085         /**
1086          * Fetch featured posts from a contact with the given url
1087          *
1088          * @param string $url
1089          * @return void
1090          */
1091         public static function fetchFeaturedPosts(string $url)
1092         {
1093                 Logger::info('Fetch featured posts', ['contact' => $url]);
1094
1095                 $apcontact = APContact::getByURL($url);
1096                 if (empty($apcontact['featured'])) {
1097                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1098                         return;
1099                 }
1100
1101                 $pcid = Contact::getIdForURL($url, 0, false);
1102                 if (empty($pcid)) {
1103                         Logger::info('Contact not found', ['contact' => $url]);
1104                         return;
1105                 }
1106
1107                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1108                 if (!empty($posts)) {
1109                         $old_featured = array_column($posts, 'uri-id');
1110                 } else {
1111                         $old_featured = [];
1112                 }
1113
1114                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1115                 if (empty($featured)) {
1116                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1117
1118                         foreach ($old_featured as $uri_id) {
1119                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1120                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1121                         }
1122                         return;
1123                 }
1124
1125                 $new = 0;
1126                 $old = 0;
1127
1128                 foreach ($featured as $post) {
1129                         if (empty($post['id'])) {
1130                                 continue;
1131                         }
1132                         $id = Item::fetchByLink($post['id']);
1133                         if (!empty($id)) {
1134                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1135                                 if (!empty($item['uri-id'])) {
1136                                         if (!$item['featured']) {
1137                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1138                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1139                                                 $new++;
1140                                         } else {
1141                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1142                                                 $old++;
1143                                         }
1144
1145                                         $index = array_search($item['uri-id'], $old_featured);
1146                                         if (!($index === false)) {
1147                                                 unset($old_featured[$index]);
1148                                         }
1149                                 }
1150                         }
1151                 }
1152
1153                 foreach ($old_featured as $uri_id) {
1154                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1155                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1156                 }
1157
1158                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1159         }
1160
1161         /**
1162          * Fetches missing posts
1163          *
1164          * @param string     $url         message URL
1165          * @param array      $child       activity array with the child of this message
1166          * @param string     $relay_actor Relay actor
1167          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1168          * @return string fetched message URL
1169          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1170          * @throws \ImagickException
1171          */
1172         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL): string
1173         {
1174                 if (!empty($child['receiver'])) {
1175                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1176                 } else {
1177                         $uid = 0;
1178                 }
1179
1180                 $object = ActivityPub::fetchContent($url, $uid);
1181                 if (empty($object)) {
1182                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1183                         return '';
1184                 }
1185
1186                 if (empty($object['id'])) {
1187                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1188                         return '';
1189                 }
1190
1191                 $signer = [];
1192
1193                 if (!empty($object['attributedTo'])) {
1194                         $attributed_to = $object['attributedTo'];
1195                         if (is_array($attributed_to)) {
1196                                 $compacted = JsonLD::compact($object);
1197                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1198                         }
1199                         $signer[] = $attributed_to;
1200                 }
1201
1202                 if (!empty($object['actor'])) {
1203                         $object_actor = $object['actor'];
1204                 } elseif (!empty($attributed_to)) {
1205                         $object_actor = $attributed_to;
1206                 } else {
1207                         // Shouldn't happen
1208                         $object_actor = '';
1209                 }
1210
1211                 $signer[] = $object_actor;
1212
1213                 if (!empty($child['author'])) {
1214                         $actor = $child['author'];
1215                         $signer[] = $actor;
1216                 } else {
1217                         $actor = $object_actor;
1218                 }
1219
1220                 if (!empty($object['published'])) {
1221                         $published = $object['published'];
1222                 } elseif (!empty($child['published'])) {
1223                         $published = $child['published'];
1224                 } else {
1225                         $published = DateTimeFormat::utcNow();
1226                 }
1227
1228                 $activity = [];
1229                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1230                 unset($object['@context']);
1231                 $activity['id'] = $object['id'];
1232                 $activity['to'] = $object['to'] ?? [];
1233                 $activity['cc'] = $object['cc'] ?? [];
1234                 $activity['actor'] = $actor;
1235                 $activity['object'] = $object;
1236                 $activity['published'] = $published;
1237                 $activity['type'] = 'Create';
1238
1239                 $ldactivity = JsonLD::compact($activity);
1240
1241                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 1;
1242
1243                 if (!empty($relay_actor)) {
1244                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1245                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1246                 } elseif (!empty($child['thread-completion'])) {
1247                         $ldactivity['thread-completion'] = $child['thread-completion'];
1248                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1249                 } else {
1250                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1251                         $ldactivity['completion-mode']   = $completion;
1252                 }
1253
1254                 if (!empty($child['type'])) {
1255                         $ldactivity['thread-children-type'] = $child['type'];
1256                 }
1257
1258                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1259                         return '';
1260                 }
1261
1262                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1263
1264                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1265
1266                 return $activity['id'];
1267         }
1268
1269         /**
1270          * Test if incoming relay messages should be accepted
1271          *
1272          * @param array $activity activity array
1273          * @param string $id      object ID
1274          * @return boolean true if message is accepted
1275          */
1276         private static function acceptIncomingMessage(array $activity, string $id): bool
1277         {
1278                 if (empty($activity['as:object'])) {
1279                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1280                         return true;
1281                 }
1282
1283                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1284                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1285                 if (Post::exists(['uri-id' => $uriid])) {
1286                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1287                         return true;
1288                 }
1289
1290                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1291                 $authorid = Contact::getIdForURL($attributed_to);
1292
1293                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1294
1295                 $messageTags = [];
1296                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1297                 if (!empty($tags)) {
1298                         foreach ($tags as $tag) {
1299                                 if ($tag['type'] != 'Hashtag') {
1300                                         continue;
1301                                 }
1302                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1303                         }
1304                 }
1305
1306                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1307         }
1308
1309         /**
1310          * perform a "follow" request
1311          *
1312          * @param array $activity
1313          * @return void
1314          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1315          * @throws \ImagickException
1316          */
1317         public static function followUser(array $activity)
1318         {
1319                 $uid = User::getIdForURL($activity['object_id']);
1320                 if (empty($uid)) {
1321                         return;
1322                 }
1323
1324                 $owner = User::getOwnerDataById($uid);
1325                 if (empty($owner)) {
1326                         return;
1327                 }
1328
1329                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1330                 if (!empty($cid)) {
1331                         self::switchContact($cid);
1332                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1333                 }
1334
1335                 $item = [
1336                         'author-id' => Contact::getIdForURL($activity['actor']),
1337                         'author-link' => $activity['actor'],
1338                 ];
1339
1340                 // Ensure that the contact has got the right network type
1341                 self::switchContact($item['author-id']);
1342
1343                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1344                 if ($result === true) {
1345                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1346                 }
1347
1348                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1349                 if (empty($cid)) {
1350                         return;
1351                 }
1352
1353                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1354                         self::transmitPendingEvents($cid, $owner['uid']);
1355                 }
1356
1357                 if (empty($contact)) {
1358                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1359                 }
1360                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1361                 Queue::remove($activity);
1362         }
1363
1364         /**
1365          * Transmit pending events to the new follower
1366          *
1367          * @param integer $cid Contact id
1368          * @param integer $uid User id
1369          * @return void
1370          */
1371         private static function transmitPendingEvents(int $cid, int $uid)
1372         {
1373                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1374                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1375
1376                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1377                 while ($event = DBA::fetch($events)) {
1378                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1379                         if (empty($post)) {
1380                                 continue;
1381                         }
1382                         if (DI::config()->get('system', 'bulk_delivery')) {
1383                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1384                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1385                         } else {
1386                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1387                         }
1388                 }
1389         }
1390
1391         /**
1392          * Update the given profile
1393          *
1394          * @param array $activity
1395          * @throws \Exception
1396          */
1397         public static function updatePerson(array $activity)
1398         {
1399                 if (empty($activity['object_id'])) {
1400                         return;
1401                 }
1402
1403                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1404                 Contact::updateFromProbeByURL($activity['object_id']);
1405                 Queue::remove($activity);
1406         }
1407
1408         /**
1409          * Delete the given profile
1410          *
1411          * @param array $activity
1412          * @return void
1413          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1414          */
1415         public static function deletePerson(array $activity)
1416         {
1417                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1418                         Logger::info('Empty object id or actor.');
1419                         return;
1420                 }
1421
1422                 if ($activity['object_id'] != $activity['actor']) {
1423                         Logger::info('Object id does not match actor.');
1424                         return;
1425                 }
1426
1427                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1428                 while ($contact = DBA::fetch($contacts)) {
1429                         Contact::remove($contact['id']);
1430                 }
1431                 DBA::close($contacts);
1432
1433                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1434                 Queue::remove($activity);
1435         }
1436
1437         /**
1438          * Blocks the user by the contact
1439          *
1440          * @param array $activity
1441          * @return void
1442          * @throws \Exception
1443          */
1444         public static function blockAccount(array $activity)
1445         {
1446                 $cid = Contact::getIdForURL($activity['actor']);
1447                 if (empty($cid)) {
1448                         return;
1449                 }
1450
1451                 $uid = User::getIdForURL($activity['object_id']);
1452                 if (empty($uid)) {
1453                         return;
1454                 }
1455
1456                 Contact\User::setIsBlocked($cid, $uid, true);
1457
1458                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1459                 Queue::remove($activity);
1460         }
1461
1462         /**
1463          * Unblocks the user by the contact
1464          *
1465          * @param array $activity
1466          * @return void
1467          * @throws \Exception
1468          */
1469         public static function unblockAccount(array $activity)
1470         {
1471                 $cid = Contact::getIdForURL($activity['actor']);
1472                 if (empty($cid)) {
1473                         return;
1474                 }
1475
1476                 $uid = User::getIdForURL($activity['object_object']);
1477                 if (empty($uid)) {
1478                         return;
1479                 }
1480
1481                 Contact\User::setIsBlocked($cid, $uid, false);
1482
1483                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1484                 Queue::remove($activity);
1485         }
1486
1487         /**
1488          * Accept a follow request
1489          *
1490          * @param array $activity
1491          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1492          * @throws \ImagickException
1493          */
1494         public static function acceptFollowUser(array $activity)
1495         {
1496                 $uid = User::getIdForURL($activity['object_actor']);
1497                 if (empty($uid)) {
1498                         return;
1499                 }
1500
1501                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1502                 if (empty($cid)) {
1503                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1504                         return;
1505                 }
1506
1507                 self::switchContact($cid);
1508
1509                 $fields = ['pending' => false];
1510
1511                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1512                 if ($contact['rel'] == Contact::FOLLOWER) {
1513                         $fields['rel'] = Contact::FRIEND;
1514                 }
1515
1516                 $condition = ['id' => $cid];
1517                 Contact::update($fields, $condition);
1518                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1519                 Queue::remove($activity);
1520         }
1521
1522         /**
1523          * Reject a follow request
1524          *
1525          * @param array $activity
1526          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1527          * @throws \ImagickException
1528          */
1529         public static function rejectFollowUser(array $activity)
1530         {
1531                 $uid = User::getIdForURL($activity['object_actor']);
1532                 if (empty($uid)) {
1533                         return;
1534                 }
1535
1536                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1537                 if (empty($cid)) {
1538                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1539                         return;
1540                 }
1541
1542                 self::switchContact($cid);
1543
1544                 $contact = Contact::getById($cid, ['rel']);
1545                 if ($contact['rel'] == Contact::SHARING) {
1546                         Contact::remove($cid);
1547                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1548                 } elseif ($contact['rel'] == Contact::FRIEND) {
1549                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1550                 } else {
1551                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1552                 }
1553                 Queue::remove($activity);
1554         }
1555
1556         /**
1557          * Undo activity like "like" or "dislike"
1558          *
1559          * @param array $activity
1560          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1561          * @throws \ImagickException
1562          */
1563         public static function undoActivity(array $activity)
1564         {
1565                 if (empty($activity['object_id'])) {
1566                         return;
1567                 }
1568
1569                 if (empty($activity['object_actor'])) {
1570                         return;
1571                 }
1572
1573                 $author_id = Contact::getIdForURL($activity['object_actor']);
1574                 if (empty($author_id)) {
1575                         return;
1576                 }
1577
1578                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1579                 Queue::remove($activity);
1580         }
1581
1582         /**
1583          * Activity to remove a follower
1584          *
1585          * @param array $activity
1586          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1587          * @throws \ImagickException
1588          */
1589         public static function undoFollowUser(array $activity)
1590         {
1591                 $uid = User::getIdForURL($activity['object_object']);
1592                 if (empty($uid)) {
1593                         return;
1594                 }
1595
1596                 $owner = User::getOwnerDataById($uid);
1597                 if (empty($owner)) {
1598                         return;
1599                 }
1600
1601                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1602                 if (empty($cid)) {
1603                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1604                         return;
1605                 }
1606
1607                 self::switchContact($cid);
1608
1609                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1610                 if (!DBA::isResult($contact)) {
1611                         return;
1612                 }
1613
1614                 Contact::removeFollower($contact);
1615                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1616                 Queue::remove($activity);
1617         }
1618
1619         /**
1620          * Switches a contact to AP if needed
1621          *
1622          * @param integer $cid Contact ID
1623          * @return void
1624          * @throws \Exception
1625          */
1626         private static function switchContact(int $cid)
1627         {
1628                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1629                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1630                         return;
1631                 }
1632
1633                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1634                 Contact::updateFromProbe($cid);
1635         }
1636
1637         /**
1638          * Collects implicit mentions like:
1639          * - the author of the parent item
1640          * - all the mentioned conversants in the parent item
1641          *
1642          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1643          * @return array
1644          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1645          */
1646         private static function getImplicitMentionList(array $parent): array
1647         {
1648                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1649
1650                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1651
1652                 $implicit_mentions = [];
1653                 if (empty($parent_author['url'])) {
1654                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1655                 } else {
1656                         $implicit_mentions[] = $parent_author['url'];
1657                         $implicit_mentions[] = $parent_author['nurl'];
1658                         $implicit_mentions[] = $parent_author['alias'];
1659                 }
1660
1661                 if (!empty($parent['alias'])) {
1662                         $implicit_mentions[] = $parent['alias'];
1663                 }
1664
1665                 foreach ($parent_terms as $term) {
1666                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1667                         if (!empty($contact['url'])) {
1668                                 $implicit_mentions[] = $contact['url'];
1669                                 $implicit_mentions[] = $contact['nurl'];
1670                                 $implicit_mentions[] = $contact['alias'];
1671                         }
1672                 }
1673
1674                 return $implicit_mentions;
1675         }
1676
1677         /**
1678          * Strips from the body prepended implicit mentions
1679          *
1680          * @param string $body
1681          * @param array $parent
1682          * @return string
1683          */
1684         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
1685         {
1686                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1687                         return $body;
1688                 }
1689
1690                 $potential_mentions = self::getImplicitMentionList($parent);
1691
1692                 $kept_mentions = [];
1693
1694                 // Extract one prepended mention at a time from the body
1695                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1696                         if (!in_array($matches[2], $potential_mentions)) {
1697                                 $kept_mentions[] = $matches[1];
1698                         }
1699
1700                         $body = $matches[3];
1701                 }
1702
1703                 // Re-appending the kept mentions to the body after extraction
1704                 $kept_mentions[] = $body;
1705
1706                 return implode('', $kept_mentions);
1707         }
1708
1709         /**
1710          * Adds links to string mentions
1711          *
1712          * @param string $body
1713          * @param array  $tags
1714          * @return string
1715          */
1716         protected static function addMentionLinks(string $body, array $tags): string
1717         {
1718                 // This prevents links to be added again to Pleroma-style mention links
1719                 $body = self::normalizeMentionLinks($body);
1720
1721                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1722                         foreach ($tags as $tag) {
1723                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1724                                         continue;
1725                                 }
1726
1727                                 $hash = substr($tag['name'], 0, 1);
1728                                 $name = substr($tag['name'], 1);
1729                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1730                                         $hash = '';
1731                                         $name = $tag['name'];
1732                                 }
1733
1734                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1735                         }
1736
1737                         return $body;
1738                 });
1739
1740                 return $body;
1741         }
1742 }