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\Cache\Enum\Duration;
  28 use Friendica\Core\Logger;
  29 use Friendica\Core\Protocol;
  30 use Friendica\Core\System;
  31 use Friendica\Core\Worker;
  32 use Friendica\Database\DBA;
  33 use Friendica\DI;
  34 use Friendica\Model\APContact;
  35 use Friendica\Model\Contact;
  36 use Friendica\Model\Conversation;
  37 use Friendica\Model\Event;
  38 use Friendica\Model\GServer;
  39 use Friendica\Model\Item;
  40 use Friendica\Model\ItemURI;
  41 use Friendica\Model\Mail;
  42 use Friendica\Model\Tag;
  43 use Friendica\Model\User;
  44 use Friendica\Model\Post;
  45 use Friendica\Protocol\Activity;
  46 use Friendica\Protocol\ActivityPub;
  47 use Friendica\Protocol\Relay;
  48 use Friendica\Util\DateTimeFormat;
  49 use Friendica\Util\HTTPSignature;
  50 use Friendica\Util\JsonLD;
  51 use Friendica\Util\Network;
  52 use Friendica\Util\Strings;
  53 use Friendica\Worker\Delivery;
  54
  55 /**
  56  * ActivityPub Processor Protocol class
  57  */
  58 class Processor
  59 {
  60         const CACHEKEY_FETCH_ACTIVITY = 'processor:fetchMissingActivity:';
  61         /**
  62          * Extracts the tag character (#, @, !) from mention links
  63          *
  64          * @param string $body
  65          * @return string
  66          */
  67         protected static function normalizeMentionLinks(string $body): string
  68         {
  69                 return preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  70         }
  71
  72         /**
  73          * Convert the language array into a language JSON
  74          *
  75          * @param array $languages
  76          * @return string language JSON
  77          */
  78         private static function processLanguages(array $languages): string
  79         {
  80                 $codes = array_keys($languages);
  81                 $lang = [];
  82                 foreach ($codes as $code) {
  83                         $lang[$code] = 1;
  84                 }
  85
  86                 if (empty($lang)) {
  87                         return '';
  88                 }
  89
  90                 return json_encode($lang);
  91         }
  92         /**
  93          * Replaces emojis in the body
  94          *
  95          * @param int $uri_id
  96          * @param string $body
  97          * @param array $emojis
  98          *
  99          * @return string with replaced emojis
 100          */
 101         private static function replaceEmojis(int $uri_id, string $body, array $emojis): string
 102         {
 103                 $body = strtr($body,
 104                         array_combine(
 105                                 array_column($emojis, 'name'),
 106                                 array_map(function ($emoji) {
 107                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 108                                 }, $emojis)
 109                         )
 110                 );
 111
 112                 // We store the emoji here to be able to avoid storing it in the media
 113                 foreach ($emojis as $emoji) {
 114                         Post\Link::getByLink($uri_id, $emoji['href']);
 115                 }
 116                 return $body;
 117         }
 118
 119         /**
 120          * Store attached media files in the post-media table
 121          *
 122          * @param int $uriid
 123          * @param array $attachment
 124          * @return void
 125          */
 126         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 127         {
 128                 if (empty($attachment['url'])) {
 129                         return;
 130                 }
 131
 132                 $data = ['uri-id' => $uriid];
 133                 $data['type'] = Post\Media::UNKNOWN;
 134                 $data['url'] = $attachment['url'];
 135                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 136                 $data['height'] = $attachment['height'] ?? null;
 137                 $data['width'] = $attachment['width'] ?? null;
 138                 $data['size'] = $attachment['size'] ?? null;
 139                 $data['preview'] = $attachment['image'] ?? null;
 140                 $data['description'] = $attachment['name'] ?? null;
 141
 142                 Post\Media::insert($data);
 143         }
 144
 145         /**
 146          * Stire attachment data
 147          *
 148          * @param array   $activity
 149          * @param array   $item
 150          */
 151         private static function storeAttachments(array $activity, array $item)
 152         {
 153                 if (empty($activity['attachments'])) {
 154                         return;
 155                 }
 156
 157                 foreach ($activity['attachments'] as $attach) {
 158                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 159                 }
 160         }
 161
 162         /**
 163          * Store attachment data
 164          *
 165          * @param array   $activity
 166          * @param array   $item
 167          */
 168         private static function storeQuestion(array $activity, array $item)
 169         {
 170                 if (empty($activity['question'])) {
 171                         return;
 172                 }
 173                 $question = ['multiple' => $activity['question']['multiple']];
 174
 175                 if (!empty($activity['question']['voters'])) {
 176                         $question['voters'] = $activity['question']['voters'];
 177                 }
 178
 179                 if (!empty($activity['question']['end-time'])) {
 180                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 181                 }
 182
 183                 Post\Question::update($item['uri-id'], $question);
 184
 185                 foreach ($activity['question']['options'] as $key => $option) {
 186                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 187                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 188                 }
 189
 190                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 191         }
 192
 193         /**
 194          * Updates a message
 195          *
 196          * @param array      $activity   Activity array
 197          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 198          * @throws \ImagickException
 199          */
 200         public static function updateItem(array $activity)
 201         {
 202                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 203                 if (!DBA::isResult($item)) {
 204                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 205                         $item = self::createItem($activity);
 206                         if (empty($item)) {
 207                                 return;
 208                         }
 209
 210                         self::postItem($activity, $item);
 211                         return;
 212                 }
 213
 214                 $item['changed'] = DateTimeFormat::utcNow();
 215                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 216
 217                 $item = self::processContent($activity, $item);
 218
 219                 self::storeAttachments($activity, $item);
 220                 self::storeQuestion($activity, $item);
 221
 222                 if (empty($item)) {
 223                         return;
 224                 }
 225
 226                 Post\History::add($item['uri-id'], $item);
 227                 Item::update($item, ['uri' => $activity['id']]);
 228
 229                 Queue::remove($activity);
 230
 231                 if ($activity['object_type'] == 'as:Event') {
 232                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 233                         while ($post = DBA::fetch($posts)) {
 234                                 self::updateEvent($post['event-id'], $activity);
 235                         }
 236                 }
 237         }
 238
 239         /**
 240          * Update an existing event
 241          *
 242          * @param int $event_id
 243          * @param array $activity
 244          */
 245         private static function updateEvent(int $event_id, array $activity)
 246         {
 247                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 248
 249                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 250                 $event['summary']  = HTML::toBBCode($activity['name']);
 251                 $event['desc']     = HTML::toBBCode($activity['content']);
 252                 if (!empty($activity['start-time'])) {
 253                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 254                 }
 255                 if (!empty($activity['end-time'])) {
 256                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 257                 }
 258                 $event['nofinish'] = empty($event['finish']);
 259                 $event['location'] = $activity['location'];
 260
 261                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 262                 Event::store($event);
 263         }
 264
 265         /**
 266          * Prepares data for a message
 267          *
 268          * @param array      $activity   Activity array
 269          * @return array Internal item
 270          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 271          * @throws \ImagickException
 272          */
 273         public static function createItem(array $activity): array
 274         {
 275                 $item = [];
 276                 $item['verb'] = Activity::POST;
 277                 $item['thr-parent'] = $activity['reply-to-id'];
 278
 279                 if ($activity['reply-to-id'] == $activity['id']) {
 280                         $item['gravity'] = GRAVITY_PARENT;
 281                         $item['object-type'] = Activity\ObjectType::NOTE;
 282                 } else {
 283                         $item['gravity'] = GRAVITY_COMMENT;
 284                         $item['object-type'] = Activity\ObjectType::COMMENT;
 285                 }
 286
 287                 if (!empty($activity['context'])) {
 288                         $item['conversation'] = $activity['context'];
 289                 } elseif (!empty($activity['conversation'])) {
 290                         $item['conversation'] = $activity['conversation'];
 291                 }
 292
 293                 if (!empty($item['conversation'])) {
 294                         $conversation = Post::selectFirstThread(['uri'], ['conversation' => $item['conversation']]);
 295                         if (!empty($conversation)) {
 296                                 Logger::debug('Got conversation', ['conversation' => $item['conversation'], 'parent' => $conversation]);
 297                                 $item['parent-uri'] = $conversation['uri'];
 298                         }
 299                 } else {
 300                         $conversation = [];
 301                 }
 302
 303                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 304                         $recursion_depth = $activity['recursion-depth'] ?? 0;
 305                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 306                         if ($recursion_depth < 10) {
 307                                 $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 308                                 if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 309                                         // Recursively delete this and all depending entries
 310                                         Queue::deleteById($activity['entry-id']);
 311                                         return [];
 312                                 }
 313                                 $fetch_by_worker = empty($result);
 314                         } else {
 315                                 Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 316                                 $fetch_by_worker = true;
 317                         }
 318
 319                         if ($fetch_by_worker && Queue::hasWorker($activity)) {
 320                                 Logger::notice('There is already a worker task to fetch the post.', ['id' => $activity['id'], 'parent' => $activity['reply-to-id']]);
 321                                 $fetch_by_worker = false;
 322                                 if (!empty($conversation)) {
 323                                         return [];
 324                                 }
 325                         }
 326
 327                         if ($fetch_by_worker) {
 328                                 Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 329                                 $activity['recursion-depth'] = 0;
 330                                 $wid = Worker::add(PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 331                                 Queue::setWorkerId($activity, $wid);
 332                                 if (!empty($conversation)) {
 333                                         return [];
 334                                 }
 335                         } elseif (!empty($result)) {
 336                                 if (($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 337                                         $item['thr-parent'] = $result;
 338                                 }
 339                         }
 340                 }
 341
 342                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 343
 344                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 345                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 346                         return [];
 347                 }
 348
 349                 $item['network'] = Protocol::ACTIVITYPUB;
 350                 $item['author-link'] = $activity['author'];
 351                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 352                 $item['owner-link'] = $activity['actor'];
 353                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 354
 355                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 356                         $item['private'] = Item::UNLISTED;
 357                 } elseif (in_array(0, $activity['receiver'])) {
 358                         $item['private'] = Item::PUBLIC;
 359                 } else {
 360                         $item['private'] = Item::PRIVATE;
 361                 }
 362
 363                 if (!empty($activity['raw'])) {
 364                         $item['source'] = $activity['raw'];
 365                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 366
 367                         if (isset($activity['push'])) {
 368                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 369                         }
 370                 }
 371
 372                 if (!empty($activity['from-relay'])) {
 373                         $item['direction'] = Conversation::RELAY;
 374                 }
 375
 376                 if ($activity['object_type'] == 'as:Article') {
 377                         $item['post-type'] = Item::PT_ARTICLE;
 378                 } elseif ($activity['object_type'] == 'as:Audio') {
 379                         $item['post-type'] = Item::PT_AUDIO;
 380                 } elseif ($activity['object_type'] == 'as:Document') {
 381                         $item['post-type'] = Item::PT_DOCUMENT;
 382                 } elseif ($activity['object_type'] == 'as:Event') {
 383                         $item['post-type'] = Item::PT_EVENT;
 384                 } elseif ($activity['object_type'] == 'as:Image') {
 385                         $item['post-type'] = Item::PT_IMAGE;
 386                 } elseif ($activity['object_type'] == 'as:Page') {
 387                         $item['post-type'] = Item::PT_PAGE;
 388                 } elseif ($activity['object_type'] == 'as:Question') {
 389                         $item['post-type'] = Item::PT_POLL;
 390                 } elseif ($activity['object_type'] == 'as:Video') {
 391                         $item['post-type'] = Item::PT_VIDEO;
 392                 } else {
 393                         $item['post-type'] = Item::PT_NOTE;
 394                 }
 395
 396                 $item['isForum'] = false;
 397
 398                 if (!empty($activity['thread-completion'])) {
 399                         if ($activity['thread-completion'] != $item['owner-id']) {
 400                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 401                                 $item['causer-link'] = $actor['url'];
 402                                 $item['causer-id'] = $activity['thread-completion'];
 403                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 404                         } else {
 405                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 406                                 $item['causer-link'] = $item['owner-link'];
 407                                 $item['causer-id']   = $item['owner-id'];
 408                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 409                         }
 410
 411                         $item['owner-link'] = $item['author-link'];
 412                         $item['owner-id'] = $item['author-id'];
 413                 } else {
 414                         $actor = APContact::getByURL($item['owner-link'], false);
 415                         $item['isForum'] = ($actor['type'] == 'Group');
 416                 }
 417
 418                 $item['uri'] = $activity['id'];
 419
 420                 if (empty($activity['published']) || empty($activity['updated'])) {
 421                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 422                 }
 423
 424                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 425                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 426                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 427                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 428
 429                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 430                 if (empty($item['uri-id'])) {
 431                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 432                         return [];
 433                 }
 434
 435                 $item = self::processContent($activity, $item);
 436                 if (empty($item)) {
 437                         Logger::info('Message was not processed');
 438                         return [];
 439                 }
 440
 441                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 442
 443                 self::storeAttachments($activity, $item);
 444                 self::storeQuestion($activity, $item);
 445
 446                 // We received the post via AP, so we set the protocol of the server to AP
 447                 $contact = Contact::getById($item['author-id'], ['gsid']);
 448                 if (!empty($contact['gsid'])) {
 449                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 450                 }
 451
 452                 if ($item['author-id'] != $item['owner-id']) {
 453                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 454                         if (!empty($contact['gsid'])) {
 455                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 456                         }
 457                 }
 458
 459                 return $item;
 460         }
 461
 462         /**
 463          * Check if a given activity is no longer available
 464          *
 465          * @param string $url
 466          *
 467          * @return boolean
 468          */
 469         public static function isActivityGone(string $url): bool
 470         {
 471                 $curlResult = HTTPSignature::fetchRaw($url, 0);
 472
 473                 if (Network::isUrlBlocked($url)) {
 474                         return true;
 475                 }
 476
 477                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 478                 if (in_array($curlResult->getReturnCode(), [404])) {
 479                         return true;
 480                 }
 481
 482                 $object = json_decode($curlResult->getBody(), true);
 483                 if (!empty($object)) {
 484                         $activity = JsonLD::compact($object);
 485                         if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 486                                 return true;
 487                         }
 488                 }
 489
 490                 return false;
 491         }
 492         /**
 493          * Delete items
 494          *
 495          * @param array $activity
 496          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 497          * @throws \ImagickException
 498          */
 499         public static function deleteItem(array $activity)
 500         {
 501                 $owner = Contact::getIdForURL($activity['actor']);
 502
 503                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 504                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 505                 Queue::remove($activity);
 506         }
 507
 508         /**
 509          * Prepare the item array for an activity
 510          *
 511          * @param array $activity Activity array
 512          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 513          * @throws \ImagickException
 514          */
 515         public static function addTag(array $activity)
 516         {
 517                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 518                         return;
 519                 }
 520
 521                 foreach ($activity['receiver'] as $receiver) {
 522                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 523                         if (!DBA::isResult($item)) {
 524                                 // We don't fetch missing content for this purpose
 525                                 continue;
 526                         }
 527
 528                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 529                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 530                                 continue;
 531                         }
 532
 533                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 534                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 535                 }
 536         }
 537
 538         /**
 539          * Prepare the item array for an activity
 540          *
 541          * @param array      $activity   Activity array
 542          * @param string     $verb       Activity verb
 543          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 544          * @throws \ImagickException
 545          */
 546         public static function createActivity(array $activity, string $verb)
 547         {
 548                 $activity['reply-to-id'] = $activity['object_id'];
 549                 $item = self::createItem($activity);
 550                 if (empty($item)) {
 551                         return;
 552                 }
 553
 554                 $item['verb'] = $verb;
 555                 $item['thr-parent'] = $activity['object_id'];
 556                 $item['gravity'] = GRAVITY_ACTIVITY;
 557                 unset($item['post-type']);
 558                 $item['object-type'] = Activity\ObjectType::NOTE;
 559
 560                 if (!empty($activity['content'])) {
 561                         $item['body'] = HTML::toBBCode($activity['content']);
 562                 }
 563
 564                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 565
 566                 self::postItem($activity, $item);
 567         }
 568
 569         /**
 570          * Fetch the Uri-Id of a post for the "featured" collection
 571          *
 572          * @param array $activity
 573          * @return null|int
 574          */
 575         private static function getUriIdForFeaturedCollection(array $activity)
 576         {
 577                 $actor = APContact::getByURL($activity['actor']);
 578                 if (empty($actor)) {
 579                         return null;
 580                 }
 581
 582                 // Refetch the account when the "featured" collection is missing.
 583                 // This can be removed in a future version (end of 2022 should be good).
 584                 if (empty($actor['featured'])) {
 585                         $actor = APContact::getByURL($activity['actor'], true);
 586                         if (empty($actor)) {
 587                                 return null;
 588                         }
 589                 }
 590
 591                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 592                 if (empty($parent['uri-id'])) {
 593                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 594                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 595                         }
 596                 }
 597
 598                 if (!empty($parent['uri-id'])) {
 599                         return $parent['uri-id'];
 600                 }
 601
 602                 return null;
 603         }
 604
 605         /**
 606          * Add a post to the "Featured" collection
 607          *
 608          * @param array $activity
 609          */
 610         public static function addToFeaturedCollection(array $activity)
 611         {
 612                 $uriid = self::getUriIdForFeaturedCollection($activity);
 613                 if (empty($uriid)) {
 614                         return;
 615                 }
 616
 617                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 618
 619                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 620                 Queue::remove($activity);
 621         }
 622
 623         /**
 624          * Remove a post to the "Featured" collection
 625          *
 626          * @param array $activity
 627          */
 628         public static function removeFromFeaturedCollection(array $activity)
 629         {
 630                 $uriid = self::getUriIdForFeaturedCollection($activity);
 631                 if (empty($uriid)) {
 632                         return;
 633                 }
 634
 635                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 636
 637                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 638                 Queue::remove($activity);
 639         }
 640
 641         /**
 642          * Create an event
 643          *
 644          * @param array $activity Activity array
 645          * @param array $item
 646          *
 647          * @return int event id
 648          * @throws \Exception
 649          */
 650         public static function createEvent(array $activity, array $item): int
 651         {
 652                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 653                 $event['desc']      = HTML::toBBCode($activity['content']);
 654                 if (!empty($activity['start-time'])) {
 655                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 656                 }
 657                 if (!empty($activity['end-time'])) {
 658                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 659                 }
 660                 $event['nofinish']  = empty($event['finish']);
 661                 $event['location']  = $activity['location'];
 662                 $event['cid']       = $item['contact-id'];
 663                 $event['uid']       = $item['uid'];
 664                 $event['uri']       = $item['uri'];
 665                 $event['edited']    = $item['edited'];
 666                 $event['private']   = $item['private'];
 667                 $event['guid']      = $item['guid'];
 668                 $event['plink']     = $item['plink'];
 669                 $event['network']   = $item['network'];
 670                 $event['protocol']  = $item['protocol'];
 671                 $event['direction'] = $item['direction'];
 672                 $event['source']    = $item['source'];
 673
 674                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 675                 if (DBA::isResult($ev)) {
 676                         $event['id'] = $ev['id'];
 677                 }
 678
 679                 $event_id = Event::store($event);
 680
 681                 Logger::info('Event was stored', ['id' => $event_id]);
 682
 683                 return $event_id;
 684         }
 685
 686         /**
 687          * Process the content
 688          *
 689          * @param array $activity Activity array
 690          * @param array $item
 691          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 692          * @throws \Exception
 693          */
 694         private static function processContent(array $activity, array $item)
 695         {
 696                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 697                         $item['title'] = strip_tags($activity['name']);
 698                         $content = Markdown::toBBCode($activity['content']);
 699                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 700                         $item['title'] = $activity['name'];
 701                         $content = $activity['content'];
 702                 } else {
 703                         // By default assume "text/html"
 704                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 705                         $content = HTML::toBBCode($activity['content'] ?? '');
 706                 }
 707
 708                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 709
 710                 if (!empty($activity['languages'])) {
 711                         $item['language'] = self::processLanguages($activity['languages']);
 712                 }
 713
 714                 if (!empty($activity['emojis'])) {
 715                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 716                 }
 717
 718                 $content = self::addMentionLinks($content, $activity['tags']);
 719
 720                 if (!empty($activity['source'])) {
 721                         $item['body'] = $activity['source'];
 722                         $item['raw-body'] = $content;
 723                         $item['body'] = Item::improveSharedDataInBody($item);
 724                 } else {
 725                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 726                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 727                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 728                                 if (!DBA::isResult($parent)) {
 729                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 730                                         return false;
 731                                 }
 732                                 if (($item['private'] == Item::PRIVATE) && ($parent['private'] != Item::PRIVATE)) {
 733                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 734                                         return false;
 735                                 }
 736
 737                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 738                         }
 739                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 740                         $item['raw-body'] = $item['body'] = $content;
 741                 }
 742
 743                 self::storeFromBody($item);
 744                 self::storeTags($item['uri-id'], $activity['tags']);
 745
 746                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 747
 748                 $item['location'] = $activity['location'];
 749
 750                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 751                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 752                 }
 753
 754                 $item['app'] = $activity['generator'];
 755
 756                 return $item;
 757         }
 758
 759         /**
 760          * Store hashtags and mentions
 761          *
 762          * @param array $item
 763          */
 764         private static function storeFromBody(array $item)
 765         {
 766                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 767                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 768
 769                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 770         }
 771
 772         /**
 773          * Generate a GUID out of an URL of an ActivityPub post.
 774          *
 775          * @param string $url message URL
 776          * @return string with GUID
 777          */
 778         private static function getGUIDByURL(string $url): string
 779         {
 780                 $parsed = parse_url($url);
 781
 782                 $host_hash = hash('crc32', $parsed['host']);
 783
 784                 unset($parsed["scheme"]);
 785                 unset($parsed["host"]);
 786
 787                 $path = implode("/", $parsed);
 788
 789                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 790         }
 791
 792         /**
 793          * Checks if an incoming message is wanted
 794          *
 795          * @param array $activity
 796          * @param array $item
 797          * @return boolean Is the message wanted?
 798          */
 799         private static function isSolicitedMessage(array $activity, array $item): bool
 800         {
 801                 // The checks are split to improve the support when searching why a message was accepted.
 802                 if (count($activity['receiver']) != 1) {
 803                         // The message has more than one receiver, so it is wanted.
 804                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 805                         return true;
 806                 }
 807
 808                 if ($item['private'] == Item::PRIVATE) {
 809                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 810                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 811                         return true;
 812                 }
 813
 814                 if (!empty($activity['from-relay'])) {
 815                         // We check relay posts at another place. When it arrived here, the message is already checked.
 816                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 817                         return true;
 818                 }
 819
 820                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 821                         // Manual completions and completions caused by reshares are allowed without any further checks.
 822                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 823                         return true;
 824                 }
 825
 826                 if ($item['gravity'] != GRAVITY_PARENT) {
 827                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 828                         // This can possibly be improved in the future.
 829                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 830                         return true;
 831                 }
 832
 833                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 834                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 835                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 836                         return true;
 837                 } else {
 838                         return false;
 839                 }
 840         }
 841
 842         /**
 843          * Creates an item post
 844          *
 845          * @param array $activity Activity data
 846          * @param array $item     item array
 847          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 848          * @throws \ImagickException
 849          */
 850         public static function postItem(array $activity, array $item)
 851         {
 852                 if (empty($item)) {
 853                         return;
 854                 }
 855
 856                 $stored = false;
 857                 $success = false;
 858                 ksort($activity['receiver']);
 859
 860                 if (!self::isSolicitedMessage($activity, $item)) {
 861                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 862                         return;
 863                 }
 864
 865                 foreach ($activity['receiver'] as $receiver) {
 866                         if ($receiver == -1) {
 867                                 continue;
 868                         }
 869
 870                         $item['uid'] = $receiver;
 871
 872                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 873                         switch($type) {
 874                                 case Receiver::TARGET_TO:
 875                                         $item['post-reason'] = Item::PR_TO;
 876                                         break;
 877                                 case Receiver::TARGET_CC:
 878                                         $item['post-reason'] = Item::PR_CC;
 879                                         break;
 880                                 case Receiver::TARGET_BTO:
 881                                         $item['post-reason'] = Item::PR_BTO;
 882                                         break;
 883                                 case Receiver::TARGET_BCC:
 884                                         $item['post-reason'] = Item::PR_BCC;
 885                                         break;
 886                                 case Receiver::TARGET_FOLLOWER:
 887                                         $item['post-reason'] = Item::PR_FOLLOWER;
 888                                         break;
 889                                 case Receiver::TARGET_ANSWER:
 890                                         $item['post-reason'] = Item::PR_COMMENT;
 891                                         break;
 892                                 case Receiver::TARGET_GLOBAL:
 893                                         $item['post-reason'] = Item::PR_GLOBAL;
 894                                         break;
 895                                 default:
 896                                         $item['post-reason'] = Item::PR_NONE;
 897                         }
 898
 899                         if (!empty($activity['from-relay'])) {
 900                                 $item['post-reason'] = Item::PR_RELAY;
 901                         } elseif (!empty($activity['thread-completion'])) {
 902                                 $item['post-reason'] = Item::PR_FETCHED;
 903                         }
 904
 905                         if ($item['isForum'] ?? false) {
 906                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 907                         } else {
 908                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 909                         }
 910
 911                         if (($receiver != 0) && empty($item['contact-id'])) {
 912                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 913                         }
 914
 915                         if (!empty($activity['directmessage'])) {
 916                                 self::postMail($activity, $item);
 917                                 continue;
 918                         }
 919
 920                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 921                                 if ($item['post-reason'] == Item::PR_BCC) {
 922                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 923                                         continue;
 924                                 }
 925
 926                                 if (
 927                                         !empty($activity['thread-children-type'])
 928                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 929                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 930                                 ) {
 931                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 932                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 933                                         continue;
 934                                 }
 935                         }
 936
 937                         $is_forum = false;
 938
 939                         if ($receiver != 0) {
 940                                 $user = User::getById($receiver, ['account-type']);
 941                                 if (!empty($user['account-type'])) {
 942                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 943                                 }
 944                         }
 945
 946                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 947                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 948
 949                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 950                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 951                                 }
 952
 953                                 if ($skip) {
 954                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 955                                         continue;
 956                                 }
 957
 958                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 959                         }
 960
 961                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 962                                 $event_id = self::createEvent($activity, $item);
 963
 964                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 965                         }
 966
 967                         $item_id = Item::insert($item);
 968                         if ($item_id) {
 969                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 970                                 $success = true;
 971                         } else {
 972                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
 973                                 if (Item::isTooOld($item) || !Item::isValid($item)) {
 974                                         Queue::remove($activity);
 975                                 }
 976                         }
 977
 978                         if ($item['uid'] == 0) {
 979                                 $stored = $item_id;
 980                         }
 981                 }
 982
 983                 if ($success) {
 984                         Queue::remove($activity);
 985
 986                         if (Queue::hasChildren($item['uri'])) {
 987                                 Worker::add(PRIORITY_HIGH, 'ProcessReplyByUri', $item['uri']);
 988                         }
 989                 }
 990
 991                 // Store send a follow request for every reshare - but only when the item had been stored
 992                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
 993                         $author = APContact::getByURL($item['owner-link'], false);
 994                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 995                         if ($author['type'] != 'Group') {
 996                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 997                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 998                         }
 999                 }
1000         }
1001
1002         /**
1003          * Store tags and mentions into the tag table
1004          *
1005          * @param integer $uriid
1006          * @param array $tags
1007          */
1008         private static function storeTags(int $uriid, array $tags = null)
1009         {
1010                 foreach ($tags as $tag) {
1011                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1012                                 continue;
1013                         }
1014
1015                         $hash = substr($tag['name'], 0, 1);
1016
1017                         if ($tag['type'] == 'Mention') {
1018                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1019                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1020                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1021                                         $tag['name'] = substr($tag['name'], 1);
1022                                 }
1023                                 $type = Tag::IMPLICIT_MENTION;
1024
1025                                 if (!empty($tag['href'])) {
1026                                         $apcontact = APContact::getByURL($tag['href']);
1027                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1028                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1029                                         }
1030                                 }
1031                         } elseif ($tag['type'] == 'Hashtag') {
1032                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1033                                         $tag['name'] = substr($tag['name'], 1);
1034                                 }
1035                                 $type = Tag::HASHTAG;
1036                         }
1037
1038                         if (empty($tag['name'])) {
1039                                 continue;
1040                         }
1041
1042                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1043                 }
1044         }
1045
1046         public static function storeReceivers(int $uriid, array $receivers)
1047         {
1048                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
1049                         if (!empty($receivers[$element])) {
1050                                 foreach ($receivers[$element] as $receiver) {
1051                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1052                                                 $name = Receiver::PUBLIC_COLLECTION;
1053                                         } else {
1054                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
1055                                         }
1056
1057                                         $target = Tag::getTargetType($receiver);
1058                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1059                                         Tag::store($uriid, $type, $name, $receiver, $target);
1060                                 }
1061                         }
1062                 }
1063         }
1064
1065         /**
1066          * Creates an mail post
1067          *
1068          * @param array $activity Activity data
1069          * @param array $item     item array
1070          * @return int|bool New mail table row id or false on error
1071          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1072          */
1073         private static function postMail(array $activity, array $item)
1074         {
1075                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1076                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1077                         return false;
1078                 }
1079
1080                 Logger::info('Direct Message', $item);
1081
1082                 $msg = [];
1083                 $msg['uid'] = $item['uid'];
1084
1085                 $msg['contact-id'] = $item['contact-id'];
1086
1087                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1088                 $msg['from-name'] = $contact['name'];
1089                 $msg['from-url'] = $contact['url'];
1090                 $msg['from-photo'] = $contact['photo'];
1091
1092                 $msg['uri'] = $item['uri'];
1093                 $msg['created'] = $item['created'];
1094
1095                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1096                 if (DBA::isResult($parent)) {
1097                         $msg['parent-uri'] = $parent['parent-uri'];
1098                         $msg['title'] = $parent['title'];
1099                 } else {
1100                         $msg['parent-uri'] = $item['thr-parent'];
1101
1102                         if (!empty($item['title'])) {
1103                                 $msg['title'] = $item['title'];
1104                         } elseif (!empty($item['content-warning'])) {
1105                                 $msg['title'] = $item['content-warning'];
1106                         } else {
1107                                 // Trying to generate a title out of the body
1108                                 $title = $item['body'];
1109
1110                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1111                                         $title = $matches[3];
1112                                 }
1113
1114                                 $title = trim(BBCode::toPlaintext($title));
1115
1116                                 if (strlen($title) > 20) {
1117                                         $title = substr($title, 0, 20) . '...';
1118                                 }
1119
1120                                 $msg['title'] = $title;
1121                         }
1122                 }
1123                 $msg['body'] = $item['body'];
1124
1125                 return Mail::insert($msg);
1126         }
1127
1128         /**
1129          * Fetch featured posts from a contact with the given url
1130          *
1131          * @param string $url
1132          * @return void
1133          */
1134         public static function fetchFeaturedPosts(string $url)
1135         {
1136                 Logger::info('Fetch featured posts', ['contact' => $url]);
1137
1138                 $apcontact = APContact::getByURL($url);
1139                 if (empty($apcontact['featured'])) {
1140                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1141                         return;
1142                 }
1143
1144                 $pcid = Contact::getIdForURL($url, 0, false);
1145                 if (empty($pcid)) {
1146                         Logger::info('Contact not found', ['contact' => $url]);
1147                         return;
1148                 }
1149
1150                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1151                 if (!empty($posts)) {
1152                         $old_featured = array_column($posts, 'uri-id');
1153                 } else {
1154                         $old_featured = [];
1155                 }
1156
1157                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1158                 if (empty($featured)) {
1159                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1160
1161                         foreach ($old_featured as $uri_id) {
1162                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1163                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1164                         }
1165                         return;
1166                 }
1167
1168                 $new = 0;
1169                 $old = 0;
1170
1171                 foreach ($featured as $post) {
1172                         if (empty($post['id'])) {
1173                                 continue;
1174                         }
1175                         $id = Item::fetchByLink($post['id']);
1176                         if (!empty($id)) {
1177                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1178                                 if (!empty($item['uri-id'])) {
1179                                         if (!$item['featured']) {
1180                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1181                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1182                                                 $new++;
1183                                         } else {
1184                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1185                                                 $old++;
1186                                         }
1187
1188                                         $index = array_search($item['uri-id'], $old_featured);
1189                                         if (!($index === false)) {
1190                                                 unset($old_featured[$index]);
1191                                         }
1192                                 }
1193                         }
1194                 }
1195
1196                 foreach ($old_featured as $uri_id) {
1197                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1198                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1199                 }
1200
1201                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1202         }
1203
1204         public static function fetchCachedActivity(string $url, int $uid): array
1205         {
1206                 $cachekey = self::CACHEKEY_FETCH_ACTIVITY . $uid . ':' . $url;
1207                 $object = DI::cache()->get($cachekey);
1208
1209                 if (!is_null($object)) {
1210                         Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
1211                         return $object;
1212                 }
1213
1214                 $object = ActivityPub::fetchContent($url, $uid);
1215                 if (empty($object)) {
1216                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1217                         return [];
1218                 }
1219
1220                 if (empty($object['id'])) {
1221                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1222                         return [];
1223                 }
1224                 DI::cache()->set($cachekey, $object, Duration::FIVE_MINUTES);
1225
1226                 Logger::debug('Activity was fetched successfully', ['url' => $url, 'uid' => $uid]);
1227
1228                 return $object;
1229         }
1230
1231         /**
1232          * Fetches missing posts
1233          *
1234          * @param string     $url         message URL
1235          * @param array      $child       activity array with the child of this message
1236          * @param string     $relay_actor Relay actor
1237          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1238          * @return string fetched message URL
1239          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1240          * @throws \ImagickException
1241          */
1242         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL): string
1243         {
1244                 if (!empty($child['receiver'])) {
1245                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1246                 } else {
1247                         $uid = 0;
1248                 }
1249
1250                 $object = self::fetchCachedActivity($url, $uid);
1251                 if (empty($object)) {
1252                         return '';
1253                 }
1254
1255                 $signer = [];
1256
1257                 if (!empty($object['attributedTo'])) {
1258                         $attributed_to = $object['attributedTo'];
1259                         if (is_array($attributed_to)) {
1260                                 $compacted = JsonLD::compact($object);
1261                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1262                         }
1263                         $signer[] = $attributed_to;
1264                 }
1265
1266                 if (!empty($object['actor'])) {
1267                         $object_actor = $object['actor'];
1268                 } elseif (!empty($attributed_to)) {
1269                         $object_actor = $attributed_to;
1270                 } else {
1271                         // Shouldn't happen
1272                         $object_actor = '';
1273                 }
1274
1275                 $signer[] = $object_actor;
1276
1277                 if (!empty($child['author'])) {
1278                         $actor = $child['author'];
1279                         $signer[] = $actor;
1280                 } else {
1281                         $actor = $object_actor;
1282                 }
1283
1284                 if (!empty($object['published'])) {
1285                         $published = $object['published'];
1286                 } elseif (!empty($child['published'])) {
1287                         $published = $child['published'];
1288                 } else {
1289                         $published = DateTimeFormat::utcNow();
1290                 }
1291
1292                 $activity = [];
1293                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1294                 unset($object['@context']);
1295                 $activity['id'] = $object['id'];
1296                 $activity['to'] = $object['to'] ?? [];
1297                 $activity['cc'] = $object['cc'] ?? [];
1298                 $activity['actor'] = $actor;
1299                 $activity['object'] = $object;
1300                 $activity['published'] = $published;
1301                 $activity['type'] = 'Create';
1302
1303                 $ldactivity = JsonLD::compact($activity);
1304
1305                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 1;
1306
1307                 if (!empty($relay_actor)) {
1308                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1309                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1310                 } elseif (!empty($child['thread-completion'])) {
1311                         $ldactivity['thread-completion'] = $child['thread-completion'];
1312                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1313                 } else {
1314                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1315                         $ldactivity['completion-mode']   = $completion;
1316                 }
1317
1318                 if (!empty($child['type'])) {
1319                         $ldactivity['thread-children-type'] = $child['type'];
1320                 }
1321
1322                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1323                         return '';
1324                 }
1325
1326                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1327
1328                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1329
1330                 return $activity['id'];
1331         }
1332
1333         /**
1334          * Test if incoming relay messages should be accepted
1335          *
1336          * @param array $activity activity array
1337          * @param string $id      object ID
1338          * @return boolean true if message is accepted
1339          */
1340         private static function acceptIncomingMessage(array $activity, string $id): bool
1341         {
1342                 if (empty($activity['as:object'])) {
1343                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1344                         return true;
1345                 }
1346
1347                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1348                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1349                 if (Post::exists(['uri-id' => $uriid])) {
1350                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1351                         return true;
1352                 }
1353
1354                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1355                 $authorid = Contact::getIdForURL($attributed_to);
1356
1357                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1358
1359                 $messageTags = [];
1360                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1361                 if (!empty($tags)) {
1362                         foreach ($tags as $tag) {
1363                                 if ($tag['type'] != 'Hashtag') {
1364                                         continue;
1365                                 }
1366                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1367                         }
1368                 }
1369
1370                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1371         }
1372
1373         /**
1374          * perform a "follow" request
1375          *
1376          * @param array $activity
1377          * @return void
1378          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1379          * @throws \ImagickException
1380          */
1381         public static function followUser(array $activity)
1382         {
1383                 $uid = User::getIdForURL($activity['object_id']);
1384                 if (empty($uid)) {
1385                         Queue::remove($activity);
1386                         return;
1387                 }
1388
1389                 $owner = User::getOwnerDataById($uid);
1390                 if (empty($owner)) {
1391                         return;
1392                 }
1393
1394                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1395                 if (!empty($cid)) {
1396                         self::switchContact($cid);
1397                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1398                 }
1399
1400                 $item = [
1401                         'author-id' => Contact::getIdForURL($activity['actor']),
1402                         'author-link' => $activity['actor'],
1403                 ];
1404
1405                 // Ensure that the contact has got the right network type
1406                 self::switchContact($item['author-id']);
1407
1408                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1409                 if ($result === true) {
1410                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1411                 }
1412
1413                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1414                 if (empty($cid)) {
1415                         return;
1416                 }
1417
1418                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1419                         self::transmitPendingEvents($cid, $owner['uid']);
1420                 }
1421
1422                 if (empty($contact)) {
1423                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1424                 }
1425                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1426                 Queue::remove($activity);
1427         }
1428
1429         /**
1430          * Transmit pending events to the new follower
1431          *
1432          * @param integer $cid Contact id
1433          * @param integer $uid User id
1434          * @return void
1435          */
1436         private static function transmitPendingEvents(int $cid, int $uid)
1437         {
1438                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1439                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1440
1441                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1442                 while ($event = DBA::fetch($events)) {
1443                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1444                         if (empty($post)) {
1445                                 continue;
1446                         }
1447                         if (DI::config()->get('system', 'bulk_delivery')) {
1448                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1449                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1450                         } else {
1451                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1452                         }
1453                 }
1454         }
1455
1456         /**
1457          * Update the given profile
1458          *
1459          * @param array $activity
1460          * @throws \Exception
1461          */
1462         public static function updatePerson(array $activity)
1463         {
1464                 if (empty($activity['object_id'])) {
1465                         return;
1466                 }
1467
1468                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1469                 Contact::updateFromProbeByURL($activity['object_id']);
1470                 Queue::remove($activity);
1471         }
1472
1473         /**
1474          * Delete the given profile
1475          *
1476          * @param array $activity
1477          * @return void
1478          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1479          */
1480         public static function deletePerson(array $activity)
1481         {
1482                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1483                         Logger::info('Empty object id or actor.');
1484                         return;
1485                 }
1486
1487                 if ($activity['object_id'] != $activity['actor']) {
1488                         Logger::info('Object id does not match actor.');
1489                         return;
1490                 }
1491
1492                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1493                 while ($contact = DBA::fetch($contacts)) {
1494                         Contact::remove($contact['id']);
1495                 }
1496                 DBA::close($contacts);
1497
1498                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1499                 Queue::remove($activity);
1500         }
1501
1502         /**
1503          * Blocks the user by the contact
1504          *
1505          * @param array $activity
1506          * @return void
1507          * @throws \Exception
1508          */
1509         public static function blockAccount(array $activity)
1510         {
1511                 $cid = Contact::getIdForURL($activity['actor']);
1512                 if (empty($cid)) {
1513                         return;
1514                 }
1515
1516                 $uid = User::getIdForURL($activity['object_id']);
1517                 if (empty($uid)) {
1518                         return;
1519                 }
1520
1521                 Contact\User::setIsBlocked($cid, $uid, true);
1522
1523                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1524                 Queue::remove($activity);
1525         }
1526
1527         /**
1528          * Unblocks the user by the contact
1529          *
1530          * @param array $activity
1531          * @return void
1532          * @throws \Exception
1533          */
1534         public static function unblockAccount(array $activity)
1535         {
1536                 $cid = Contact::getIdForURL($activity['actor']);
1537                 if (empty($cid)) {
1538                         return;
1539                 }
1540
1541                 $uid = User::getIdForURL($activity['object_object']);
1542                 if (empty($uid)) {
1543                         return;
1544                 }
1545
1546                 Contact\User::setIsBlocked($cid, $uid, false);
1547
1548                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1549                 Queue::remove($activity);
1550         }
1551
1552         /**
1553          * Accept a follow request
1554          *
1555          * @param array $activity
1556          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1557          * @throws \ImagickException
1558          */
1559         public static function acceptFollowUser(array $activity)
1560         {
1561                 $uid = User::getIdForURL($activity['object_actor']);
1562                 if (empty($uid)) {
1563                         return;
1564                 }
1565
1566                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1567                 if (empty($cid)) {
1568                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1569                         return;
1570                 }
1571
1572                 self::switchContact($cid);
1573
1574                 $fields = ['pending' => false];
1575
1576                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1577                 if ($contact['rel'] == Contact::FOLLOWER) {
1578                         $fields['rel'] = Contact::FRIEND;
1579                 }
1580
1581                 $condition = ['id' => $cid];
1582                 Contact::update($fields, $condition);
1583                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1584                 Queue::remove($activity);
1585         }
1586
1587         /**
1588          * Reject a follow request
1589          *
1590          * @param array $activity
1591          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1592          * @throws \ImagickException
1593          */
1594         public static function rejectFollowUser(array $activity)
1595         {
1596                 $uid = User::getIdForURL($activity['object_actor']);
1597                 if (empty($uid)) {
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                 $contact = Contact::getById($cid, ['rel']);
1610                 if ($contact['rel'] == Contact::SHARING) {
1611                         Contact::remove($cid);
1612                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1613                 } elseif ($contact['rel'] == Contact::FRIEND) {
1614                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1615                 } else {
1616                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1617                 }
1618                 Queue::remove($activity);
1619         }
1620
1621         /**
1622          * Undo activity like "like" or "dislike"
1623          *
1624          * @param array $activity
1625          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1626          * @throws \ImagickException
1627          */
1628         public static function undoActivity(array $activity)
1629         {
1630                 if (empty($activity['object_id'])) {
1631                         return;
1632                 }
1633
1634                 if (empty($activity['object_actor'])) {
1635                         return;
1636                 }
1637
1638                 $author_id = Contact::getIdForURL($activity['object_actor']);
1639                 if (empty($author_id)) {
1640                         return;
1641                 }
1642
1643                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1644                 Queue::remove($activity);
1645         }
1646
1647         /**
1648          * Activity to remove a follower
1649          *
1650          * @param array $activity
1651          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1652          * @throws \ImagickException
1653          */
1654         public static function undoFollowUser(array $activity)
1655         {
1656                 $uid = User::getIdForURL($activity['object_object']);
1657                 if (empty($uid)) {
1658                         return;
1659                 }
1660
1661                 $owner = User::getOwnerDataById($uid);
1662                 if (empty($owner)) {
1663                         return;
1664                 }
1665
1666                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1667                 if (empty($cid)) {
1668                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1669                         return;
1670                 }
1671
1672                 self::switchContact($cid);
1673
1674                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1675                 if (!DBA::isResult($contact)) {
1676                         return;
1677                 }
1678
1679                 Contact::removeFollower($contact);
1680                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1681                 Queue::remove($activity);
1682         }
1683
1684         /**
1685          * Switches a contact to AP if needed
1686          *
1687          * @param integer $cid Contact ID
1688          * @return void
1689          * @throws \Exception
1690          */
1691         private static function switchContact(int $cid)
1692         {
1693                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1694                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1695                         return;
1696                 }
1697
1698                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1699                 Contact::updateFromProbe($cid);
1700         }
1701
1702         /**
1703          * Collects implicit mentions like:
1704          * - the author of the parent item
1705          * - all the mentioned conversants in the parent item
1706          *
1707          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1708          * @return array
1709          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1710          */
1711         private static function getImplicitMentionList(array $parent): array
1712         {
1713                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1714
1715                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1716
1717                 $implicit_mentions = [];
1718                 if (empty($parent_author['url'])) {
1719                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1720                 } else {
1721                         $implicit_mentions[] = $parent_author['url'];
1722                         $implicit_mentions[] = $parent_author['nurl'];
1723                         $implicit_mentions[] = $parent_author['alias'];
1724                 }
1725
1726                 if (!empty($parent['alias'])) {
1727                         $implicit_mentions[] = $parent['alias'];
1728                 }
1729
1730                 foreach ($parent_terms as $term) {
1731                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1732                         if (!empty($contact['url'])) {
1733                                 $implicit_mentions[] = $contact['url'];
1734                                 $implicit_mentions[] = $contact['nurl'];
1735                                 $implicit_mentions[] = $contact['alias'];
1736                         }
1737                 }
1738
1739                 return $implicit_mentions;
1740         }
1741
1742         /**
1743          * Strips from the body prepended implicit mentions
1744          *
1745          * @param string $body
1746          * @param array $parent
1747          * @return string
1748          */
1749         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
1750         {
1751                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1752                         return $body;
1753                 }
1754
1755                 $potential_mentions = self::getImplicitMentionList($parent);
1756
1757                 $kept_mentions = [];
1758
1759                 // Extract one prepended mention at a time from the body
1760                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1761                         if (!in_array($matches[2], $potential_mentions)) {
1762                                 $kept_mentions[] = $matches[1];
1763                         }
1764
1765                         $body = $matches[3];
1766                 }
1767
1768                 // Re-appending the kept mentions to the body after extraction
1769                 $kept_mentions[] = $body;
1770
1771                 return implode('', $kept_mentions);
1772         }
1773
1774         /**
1775          * Adds links to string mentions
1776          *
1777          * @param string $body
1778          * @param array  $tags
1779          * @return string
1780          */
1781         protected static function addMentionLinks(string $body, array $tags): string
1782         {
1783                 // This prevents links to be added again to Pleroma-style mention links
1784                 $body = self::normalizeMentionLinks($body);
1785
1786                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1787                         foreach ($tags as $tag) {
1788                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1789                                         continue;
1790                                 }
1791
1792                                 $hash = substr($tag['name'], 0, 1);
1793                                 $name = substr($tag['name'], 1);
1794                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1795                                         $hash = '';
1796                                         $name = $tag['name'];
1797                                 }
1798
1799                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1800                         }
1801
1802                         return $body;
1803                 });
1804
1805                 return $body;
1806         }
1807 }