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, $item);
 218                 if (empty($item)) {
 219                         return;
 220                 }
 221
 222                 self::storeAttachments($activity, $item);
 223                 self::storeQuestion($activity, $item);
 224
 225                 Post\History::add($item['uri-id'], $item);
 226                 Item::update($item, ['uri' => $activity['id']]);
 227
 228                 Queue::remove($activity);
 229
 230                 if ($activity['object_type'] == 'as:Event') {
 231                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 232                         while ($post = DBA::fetch($posts)) {
 233                                 self::updateEvent($post['event-id'], $activity);
 234                         }
 235                 }
 236         }
 237
 238         /**
 239          * Update an existing event
 240          *
 241          * @param int $event_id
 242          * @param array $activity
 243          */
 244         private static function updateEvent(int $event_id, array $activity)
 245         {
 246                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 247
 248                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 249                 $event['summary']  = HTML::toBBCode($activity['name']);
 250                 $event['desc']     = HTML::toBBCode($activity['content']);
 251                 if (!empty($activity['start-time'])) {
 252                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 253                 }
 254                 if (!empty($activity['end-time'])) {
 255                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 256                 }
 257                 $event['nofinish'] = empty($event['finish']);
 258                 $event['location'] = $activity['location'];
 259
 260                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 261                 Event::store($event);
 262         }
 263
 264         /**
 265          * Prepares data for a message
 266          *
 267          * @param array      $activity   Activity array
 268          * @return array Internal item
 269          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 270          * @throws \ImagickException
 271          */
 272         public static function createItem(array $activity): array
 273         {
 274                 $item = [];
 275                 $item['verb'] = Activity::POST;
 276                 $item['thr-parent'] = $activity['reply-to-id'];
 277
 278                 if ($activity['reply-to-id'] == $activity['id']) {
 279                         $item['gravity'] = GRAVITY_PARENT;
 280                         $item['object-type'] = Activity\ObjectType::NOTE;
 281                 } else {
 282                         $item['gravity'] = GRAVITY_COMMENT;
 283                         $item['object-type'] = Activity\ObjectType::COMMENT;
 284                 }
 285
 286                 if (!empty($activity['context'])) {
 287                         $item['conversation'] = $activity['context'];
 288                 } elseif (!empty($activity['conversation'])) {
 289                         $item['conversation'] = $activity['conversation'];
 290                 }
 291
 292                 if (!empty($item['conversation'])) {
 293                         $conversation = Post::selectFirstThread(['uri'], ['conversation' => $item['conversation']]);
 294                         if (!empty($conversation)) {
 295                                 Logger::debug('Got conversation', ['conversation' => $item['conversation'], 'parent' => $conversation]);
 296                                 $item['parent-uri'] = $conversation['uri'];
 297                         }
 298                 } else {
 299                         $conversation = [];
 300                 }
 301
 302                 if (empty($activity['author']) && empty($activity['actor'])) {
 303                         Logger::notice('Missing author and actor. We quit here.', ['activity' => $activity]);
 304                         return [];
 305                 }
 306
 307                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 308                         $recursion_depth = $activity['recursion-depth'] ?? 0;
 309                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 310                         if ($recursion_depth < DI::config()->get('system', 'max_recursion_depth')) {
 311                                 $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 312                                 if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 313                                         // Recursively delete this and all depending entries
 314                                         if (!empty($activity['entry-id'])) {
 315                                                 Queue::deleteById($activity['entry-id']);
 316                                         }
 317                                         return [];
 318                                 }
 319                                 $fetch_by_worker = empty($result);
 320                         } else {
 321                                 Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 322                                 $fetch_by_worker = true;
 323                         }
 324
 325                         if ($fetch_by_worker && Queue::hasWorker($activity)) {
 326                                 Logger::notice('There is already a worker task to fetch the post.', ['id' => $activity['id'], 'parent' => $activity['reply-to-id']]);
 327                                 $fetch_by_worker = false;
 328                                 if (!empty($conversation)) {
 329                                         return [];
 330                                 }
 331                         }
 332
 333                         if ($fetch_by_worker) {
 334                                 Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 335                                 $activity['recursion-depth'] = 0;
 336                                 if (!Fetch::hasWorker($activity['reply-to-id'])) {
 337                                         Fetch::add($activity['reply-to-id']);
 338                                         $wid = Worker::add(PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 339                                         Fetch::setWorkerId($activity['reply-to-id'], $wid);
 340                                         Queue::setWorkerId($activity, $wid);
 341                                 } else {
 342                                         Logger::debug('Activity is already in the fetching process', ['url' => $activity['reply-to-id']]);
 343                                 }
 344                                 if (!empty($conversation)) {
 345                                         return [];
 346                                 }
 347                         } elseif (!empty($result)) {
 348                                 if (($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 349                                         $item['thr-parent'] = $result;
 350                                 }
 351                         }
 352                 }
 353
 354                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 355
 356                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 357                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 358                         return [];
 359                 }
 360
 361                 $item['network'] = Protocol::ACTIVITYPUB;
 362                 $item['author-link'] = $activity['author'];
 363                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 364                 $item['owner-link'] = $activity['actor'];
 365                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 366
 367                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 368                         $item['private'] = Item::UNLISTED;
 369                 } elseif (in_array(0, $activity['receiver'])) {
 370                         $item['private'] = Item::PUBLIC;
 371                 } else {
 372                         $item['private'] = Item::PRIVATE;
 373                 }
 374
 375                 if (!empty($activity['raw'])) {
 376                         $item['source'] = $activity['raw'];
 377                 }
 378
 379                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 380
 381                 if (isset($activity['push'])) {
 382                         $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 383                 }
 384
 385                 if (!empty($activity['from-relay'])) {
 386                         $item['direction'] = Conversation::RELAY;
 387                 }
 388
 389                 if ($activity['object_type'] == 'as:Article') {
 390                         $item['post-type'] = Item::PT_ARTICLE;
 391                 } elseif ($activity['object_type'] == 'as:Audio') {
 392                         $item['post-type'] = Item::PT_AUDIO;
 393                 } elseif ($activity['object_type'] == 'as:Document') {
 394                         $item['post-type'] = Item::PT_DOCUMENT;
 395                 } elseif ($activity['object_type'] == 'as:Event') {
 396                         $item['post-type'] = Item::PT_EVENT;
 397                 } elseif ($activity['object_type'] == 'as:Image') {
 398                         $item['post-type'] = Item::PT_IMAGE;
 399                 } elseif ($activity['object_type'] == 'as:Page') {
 400                         $item['post-type'] = Item::PT_PAGE;
 401                 } elseif ($activity['object_type'] == 'as:Question') {
 402                         $item['post-type'] = Item::PT_POLL;
 403                 } elseif ($activity['object_type'] == 'as:Video') {
 404                         $item['post-type'] = Item::PT_VIDEO;
 405                 } else {
 406                         $item['post-type'] = Item::PT_NOTE;
 407                 }
 408
 409                 $item['isForum'] = false;
 410
 411                 if (!empty($activity['thread-completion'])) {
 412                         if ($activity['thread-completion'] != $item['owner-id']) {
 413                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 414                                 $item['causer-link'] = $actor['url'];
 415                                 $item['causer-id'] = $activity['thread-completion'];
 416                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 417                         } else {
 418                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 419                                 $item['causer-link'] = $item['owner-link'];
 420                                 $item['causer-id']   = $item['owner-id'];
 421                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 422                         }
 423
 424                         $item['owner-link'] = $item['author-link'];
 425                         $item['owner-id'] = $item['author-id'];
 426                 } else {
 427                         $actor = APContact::getByURL($item['owner-link'], false);
 428                         $item['isForum'] = ($actor['type'] == 'Group');
 429                 }
 430
 431                 $item['uri'] = $activity['id'];
 432
 433                 if (empty($activity['published']) || empty($activity['updated'])) {
 434                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 435                 }
 436
 437                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 438                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 439                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 440                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 441
 442                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 443                 if (empty($item['uri-id'])) {
 444                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 445                         return [];
 446                 }
 447
 448                 $item = self::processContent($activity, $item);
 449                 if (empty($item)) {
 450                         Logger::info('Message was not processed');
 451                         return [];
 452                 }
 453
 454                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 455
 456                 self::storeAttachments($activity, $item);
 457                 self::storeQuestion($activity, $item);
 458
 459                 // We received the post via AP, so we set the protocol of the server to AP
 460                 $contact = Contact::getById($item['author-id'], ['gsid']);
 461                 if (!empty($contact['gsid'])) {
 462                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 463                 }
 464
 465                 if ($item['author-id'] != $item['owner-id']) {
 466                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 467                         if (!empty($contact['gsid'])) {
 468                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 469                         }
 470                 }
 471
 472                 return $item;
 473         }
 474
 475         /**
 476          * Check if a given activity is no longer available
 477          *
 478          * @param string $url
 479          *
 480          * @return boolean
 481          */
 482         public static function isActivityGone(string $url): bool
 483         {
 484                 $curlResult = HTTPSignature::fetchRaw($url, 0);
 485
 486                 if (Network::isUrlBlocked($url)) {
 487                         return true;
 488                 }
 489
 490                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 491                 if (in_array($curlResult->getReturnCode(), [404])) {
 492                         return true;
 493                 }
 494
 495                 $object = json_decode($curlResult->getBody(), true);
 496                 if (!empty($object)) {
 497                         $activity = JsonLD::compact($object);
 498                         if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 499                                 return true;
 500                         }
 501                 }
 502
 503                 return false;
 504         }
 505         /**
 506          * Delete items
 507          *
 508          * @param array $activity
 509          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 510          * @throws \ImagickException
 511          */
 512         public static function deleteItem(array $activity)
 513         {
 514                 $owner = Contact::getIdForURL($activity['actor']);
 515
 516                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 517                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 518                 Queue::remove($activity);
 519         }
 520
 521         /**
 522          * Prepare the item array for an activity
 523          *
 524          * @param array $activity Activity array
 525          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 526          * @throws \ImagickException
 527          */
 528         public static function addTag(array $activity)
 529         {
 530                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 531                         return;
 532                 }
 533
 534                 foreach ($activity['receiver'] as $receiver) {
 535                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 536                         if (!DBA::isResult($item)) {
 537                                 // We don't fetch missing content for this purpose
 538                                 continue;
 539                         }
 540
 541                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 542                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 543                                 continue;
 544                         }
 545
 546                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 547                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 548                 }
 549         }
 550
 551         /**
 552          * Prepare the item array for an activity
 553          *
 554          * @param array      $activity   Activity array
 555          * @param string     $verb       Activity verb
 556          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 557          * @throws \ImagickException
 558          */
 559         public static function createActivity(array $activity, string $verb)
 560         {
 561                 $activity['reply-to-id'] = $activity['object_id'];
 562                 $item = self::createItem($activity);
 563                 if (empty($item)) {
 564                         return;
 565                 }
 566
 567                 $item['verb'] = $verb;
 568                 $item['thr-parent'] = $activity['object_id'];
 569                 $item['gravity'] = GRAVITY_ACTIVITY;
 570                 unset($item['post-type']);
 571                 $item['object-type'] = Activity\ObjectType::NOTE;
 572
 573                 if (!empty($activity['content'])) {
 574                         $item['body'] = HTML::toBBCode($activity['content']);
 575                 }
 576
 577                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 578
 579                 self::postItem($activity, $item);
 580         }
 581
 582         /**
 583          * Fetch the Uri-Id of a post for the "featured" collection
 584          *
 585          * @param array $activity
 586          * @return null|int
 587          */
 588         private static function getUriIdForFeaturedCollection(array $activity)
 589         {
 590                 $actor = APContact::getByURL($activity['actor']);
 591                 if (empty($actor)) {
 592                         return null;
 593                 }
 594
 595                 // Refetch the account when the "featured" collection is missing.
 596                 // This can be removed in a future version (end of 2022 should be good).
 597                 if (empty($actor['featured'])) {
 598                         $actor = APContact::getByURL($activity['actor'], true);
 599                         if (empty($actor)) {
 600                                 return null;
 601                         }
 602                 }
 603
 604                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 605                 if (empty($parent['uri-id'])) {
 606                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 607                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 608                         }
 609                 }
 610
 611                 if (!empty($parent['uri-id'])) {
 612                         return $parent['uri-id'];
 613                 }
 614
 615                 return null;
 616         }
 617
 618         /**
 619          * Add a post to the "Featured" collection
 620          *
 621          * @param array $activity
 622          */
 623         public static function addToFeaturedCollection(array $activity)
 624         {
 625                 $uriid = self::getUriIdForFeaturedCollection($activity);
 626                 if (empty($uriid)) {
 627                         return;
 628                 }
 629
 630                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 631
 632                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 633                 Queue::remove($activity);
 634         }
 635
 636         /**
 637          * Remove a post to the "Featured" collection
 638          *
 639          * @param array $activity
 640          */
 641         public static function removeFromFeaturedCollection(array $activity)
 642         {
 643                 $uriid = self::getUriIdForFeaturedCollection($activity);
 644                 if (empty($uriid)) {
 645                         return;
 646                 }
 647
 648                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 649
 650                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 651                 Queue::remove($activity);
 652         }
 653
 654         /**
 655          * Create an event
 656          *
 657          * @param array $activity Activity array
 658          * @param array $item
 659          *
 660          * @return int event id
 661          * @throws \Exception
 662          */
 663         public static function createEvent(array $activity, array $item): int
 664         {
 665                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 666                 $event['desc']      = HTML::toBBCode($activity['content']);
 667                 if (!empty($activity['start-time'])) {
 668                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 669                 }
 670                 if (!empty($activity['end-time'])) {
 671                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 672                 }
 673                 $event['nofinish']  = empty($event['finish']);
 674                 $event['location']  = $activity['location'];
 675                 $event['cid']       = $item['contact-id'];
 676                 $event['uid']       = $item['uid'];
 677                 $event['uri']       = $item['uri'];
 678                 $event['edited']    = $item['edited'];
 679                 $event['private']   = $item['private'];
 680                 $event['guid']      = $item['guid'];
 681                 $event['plink']     = $item['plink'];
 682                 $event['network']   = $item['network'];
 683                 $event['protocol']  = $item['protocol'];
 684                 $event['direction'] = $item['direction'];
 685                 $event['source']    = $item['source'];
 686
 687                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 688                 if (DBA::isResult($ev)) {
 689                         $event['id'] = $ev['id'];
 690                 }
 691
 692                 $event_id = Event::store($event);
 693
 694                 Logger::info('Event was stored', ['id' => $event_id]);
 695
 696                 return $event_id;
 697         }
 698
 699         /**
 700          * Process the content
 701          *
 702          * @param array $activity Activity array
 703          * @param array $item
 704          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 705          * @throws \Exception
 706          */
 707         private static function processContent(array $activity, array $item)
 708         {
 709                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 710                         $item['title'] = strip_tags($activity['name']);
 711                         $content = Markdown::toBBCode($activity['content']);
 712                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 713                         $item['title'] = $activity['name'];
 714                         $content = $activity['content'];
 715                 } else {
 716                         // By default assume "text/html"
 717                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 718                         $content = HTML::toBBCode($activity['content'] ?? '');
 719                 }
 720
 721                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 722
 723                 if (!empty($activity['languages'])) {
 724                         $item['language'] = self::processLanguages($activity['languages']);
 725                 }
 726
 727                 if (!empty($activity['emojis'])) {
 728                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 729                 }
 730
 731                 $content = self::addMentionLinks($content, $activity['tags']);
 732
 733                 if (!empty($activity['source'])) {
 734                         $item['body'] = $activity['source'];
 735                         $item['raw-body'] = $content;
 736                         $item['body'] = Item::improveSharedDataInBody($item);
 737                 } else {
 738                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 739                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 740                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 741                                 if (!DBA::isResult($parent)) {
 742                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 743                                         return false;
 744                                 }
 745                                 if (($item['private'] == Item::PRIVATE) && ($parent['private'] != Item::PRIVATE)) {
 746                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 747                                         return false;
 748                                 }
 749
 750                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 751                         }
 752                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 753                         $item['raw-body'] = $item['body'] = $content;
 754                 }
 755
 756                 self::storeFromBody($item);
 757                 self::storeTags($item['uri-id'], $activity['tags']);
 758
 759                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 760
 761                 $item['location'] = $activity['location'];
 762
 763                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 764                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 765                 }
 766
 767                 $item['app'] = $activity['generator'];
 768
 769                 return $item;
 770         }
 771
 772         /**
 773          * Store hashtags and mentions
 774          *
 775          * @param array $item
 776          */
 777         private static function storeFromBody(array $item)
 778         {
 779                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 780                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 781
 782                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 783         }
 784
 785         /**
 786          * Generate a GUID out of an URL of an ActivityPub post.
 787          *
 788          * @param string $url message URL
 789          * @return string with GUID
 790          */
 791         private static function getGUIDByURL(string $url): string
 792         {
 793                 $parsed = parse_url($url);
 794
 795                 $host_hash = hash('crc32', $parsed['host']);
 796
 797                 unset($parsed["scheme"]);
 798                 unset($parsed["host"]);
 799
 800                 $path = implode("/", $parsed);
 801
 802                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 803         }
 804
 805         /**
 806          * Checks if an incoming message is wanted
 807          *
 808          * @param array $activity
 809          * @param array $item
 810          * @return boolean Is the message wanted?
 811          */
 812         private static function isSolicitedMessage(array $activity, array $item): bool
 813         {
 814                 // The checks are split to improve the support when searching why a message was accepted.
 815                 if (count($activity['receiver']) != 1) {
 816                         // The message has more than one receiver, so it is wanted.
 817                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 818                         return true;
 819                 }
 820
 821                 if ($item['private'] == Item::PRIVATE) {
 822                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 823                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 824                         return true;
 825                 }
 826
 827                 if (!empty($activity['from-relay'])) {
 828                         // We check relay posts at another place. When it arrived here, the message is already checked.
 829                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 830                         return true;
 831                 }
 832
 833                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 834                         // Manual completions and completions caused by reshares are allowed without any further checks.
 835                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 836                         return true;
 837                 }
 838
 839                 if ($item['gravity'] != GRAVITY_PARENT) {
 840                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 841                         // This can possibly be improved in the future.
 842                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 843                         return true;
 844                 }
 845
 846                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 847                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 848                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 849                         return true;
 850                 } else {
 851                         return false;
 852                 }
 853         }
 854
 855         /**
 856          * Creates an item post
 857          *
 858          * @param array $activity Activity data
 859          * @param array $item     item array
 860          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 861          * @throws \ImagickException
 862          */
 863         public static function postItem(array $activity, array $item)
 864         {
 865                 if (empty($item)) {
 866                         return;
 867                 }
 868
 869                 $stored = false;
 870                 $success = false;
 871                 ksort($activity['receiver']);
 872
 873                 if (!self::isSolicitedMessage($activity, $item)) {
 874                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 875                         return;
 876                 }
 877
 878                 foreach ($activity['receiver'] as $receiver) {
 879                         if ($receiver == -1) {
 880                                 continue;
 881                         }
 882
 883                         $item['uid'] = $receiver;
 884
 885                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 886                         switch($type) {
 887                                 case Receiver::TARGET_TO:
 888                                         $item['post-reason'] = Item::PR_TO;
 889                                         break;
 890                                 case Receiver::TARGET_CC:
 891                                         $item['post-reason'] = Item::PR_CC;
 892                                         break;
 893                                 case Receiver::TARGET_BTO:
 894                                         $item['post-reason'] = Item::PR_BTO;
 895                                         break;
 896                                 case Receiver::TARGET_BCC:
 897                                         $item['post-reason'] = Item::PR_BCC;
 898                                         break;
 899                                 case Receiver::TARGET_FOLLOWER:
 900                                         $item['post-reason'] = Item::PR_FOLLOWER;
 901                                         break;
 902                                 case Receiver::TARGET_ANSWER:
 903                                         $item['post-reason'] = Item::PR_COMMENT;
 904                                         break;
 905                                 case Receiver::TARGET_GLOBAL:
 906                                         $item['post-reason'] = Item::PR_GLOBAL;
 907                                         break;
 908                                 default:
 909                                         $item['post-reason'] = Item::PR_NONE;
 910                         }
 911
 912                         if (!empty($activity['from-relay'])) {
 913                                 $item['post-reason'] = Item::PR_RELAY;
 914                         } elseif (!empty($activity['thread-completion'])) {
 915                                 $item['post-reason'] = Item::PR_FETCHED;
 916                         } elseif (in_array($item['post-reason'], [Item::PR_GLOBAL, Item::PR_NONE]) && !empty($activity['push'])) {
 917                                 $item['post-reason'] = Item::PR_PUSHED;
 918                         }
 919
 920                         if ($item['isForum'] ?? false) {
 921                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 922                         } else {
 923                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 924                         }
 925
 926                         if (($receiver != 0) && empty($item['contact-id'])) {
 927                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 928                         }
 929
 930                         if (!empty($activity['directmessage'])) {
 931                                 self::postMail($activity, $item);
 932                                 continue;
 933                         }
 934
 935                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 936                                 if ($item['post-reason'] == Item::PR_BCC) {
 937                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 938                                         continue;
 939                                 }
 940
 941                                 if (
 942                                         !empty($activity['thread-children-type'])
 943                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 944                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 945                                 ) {
 946                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 947                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 948                                         continue;
 949                                 }
 950                         }
 951
 952                         $is_forum = false;
 953
 954                         if ($receiver != 0) {
 955                                 $user = User::getById($receiver, ['account-type']);
 956                                 if (!empty($user['account-type'])) {
 957                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 958                                 }
 959                         }
 960
 961                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 962                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 963
 964                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 965                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 966                                 }
 967
 968                                 if ($skip) {
 969                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 970                                         continue;
 971                                 }
 972
 973                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 974                         }
 975
 976                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 977                                 $event_id = self::createEvent($activity, $item);
 978
 979                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 980                         }
 981
 982                         $item_id = Item::insert($item);
 983                         if ($item_id) {
 984                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 985                                 $success = true;
 986                         } else {
 987                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
 988                         }
 989
 990                         if ($item['uid'] == 0) {
 991                                 $stored = $item_id;
 992                         }
 993                 }
 994
 995                 Queue::remove($activity);
 996
 997                 if ($success && Queue::hasChildren($item['uri'])) {
 998                         Worker::add(PRIORITY_HIGH, 'ProcessReplyByUri', $item['uri']);
 999                 }
1000
1001                 // Store send a follow request for every reshare - but only when the item had been stored
1002                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
1003                         $author = APContact::getByURL($item['owner-link'], false);
1004                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
1005                         if ($author['type'] != 'Group') {
1006                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
1007                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
1008                         }
1009                 }
1010         }
1011
1012         /**
1013          * Store tags and mentions into the tag table
1014          *
1015          * @param integer $uriid
1016          * @param array $tags
1017          */
1018         private static function storeTags(int $uriid, array $tags = null)
1019         {
1020                 foreach ($tags as $tag) {
1021                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1022                                 continue;
1023                         }
1024
1025                         $hash = substr($tag['name'], 0, 1);
1026
1027                         if ($tag['type'] == 'Mention') {
1028                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1029                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1030                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1031                                         $tag['name'] = substr($tag['name'], 1);
1032                                 }
1033                                 $type = Tag::IMPLICIT_MENTION;
1034
1035                                 if (!empty($tag['href'])) {
1036                                         $apcontact = APContact::getByURL($tag['href']);
1037                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1038                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1039                                         }
1040                                 }
1041                         } elseif ($tag['type'] == 'Hashtag') {
1042                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1043                                         $tag['name'] = substr($tag['name'], 1);
1044                                 }
1045                                 $type = Tag::HASHTAG;
1046                         }
1047
1048                         if (empty($tag['name'])) {
1049                                 continue;
1050                         }
1051
1052                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1053                 }
1054         }
1055
1056         public static function storeReceivers(int $uriid, array $receivers)
1057         {
1058                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
1059                         if (!empty($receivers[$element])) {
1060                                 foreach ($receivers[$element] as $receiver) {
1061                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1062                                                 $name = Receiver::PUBLIC_COLLECTION;
1063                                         } else {
1064                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
1065                                         }
1066
1067                                         $target = Tag::getTargetType($receiver);
1068                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1069                                         Tag::store($uriid, $type, $name, $receiver, $target);
1070                                 }
1071                         }
1072                 }
1073         }
1074
1075         /**
1076          * Creates an mail post
1077          *
1078          * @param array $activity Activity data
1079          * @param array $item     item array
1080          * @return int|bool New mail table row id or false on error
1081          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1082          */
1083         private static function postMail(array $activity, array $item)
1084         {
1085                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1086                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1087                         return false;
1088                 }
1089
1090                 Logger::info('Direct Message', $item);
1091
1092                 $msg = [];
1093                 $msg['uid'] = $item['uid'];
1094
1095                 $msg['contact-id'] = $item['contact-id'];
1096
1097                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1098                 $msg['from-name'] = $contact['name'];
1099                 $msg['from-url'] = $contact['url'];
1100                 $msg['from-photo'] = $contact['photo'];
1101
1102                 $msg['uri'] = $item['uri'];
1103                 $msg['created'] = $item['created'];
1104
1105                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1106                 if (DBA::isResult($parent)) {
1107                         $msg['parent-uri'] = $parent['parent-uri'];
1108                         $msg['title'] = $parent['title'];
1109                 } else {
1110                         $msg['parent-uri'] = $item['thr-parent'];
1111
1112                         if (!empty($item['title'])) {
1113                                 $msg['title'] = $item['title'];
1114                         } elseif (!empty($item['content-warning'])) {
1115                                 $msg['title'] = $item['content-warning'];
1116                         } else {
1117                                 // Trying to generate a title out of the body
1118                                 $title = $item['body'];
1119
1120                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1121                                         $title = $matches[3];
1122                                 }
1123
1124                                 $title = trim(BBCode::toPlaintext($title));
1125
1126                                 if (strlen($title) > 20) {
1127                                         $title = substr($title, 0, 20) . '...';
1128                                 }
1129
1130                                 $msg['title'] = $title;
1131                         }
1132                 }
1133                 $msg['body'] = $item['body'];
1134
1135                 return Mail::insert($msg);
1136         }
1137
1138         /**
1139          * Fetch featured posts from a contact with the given url
1140          *
1141          * @param string $url
1142          * @return void
1143          */
1144         public static function fetchFeaturedPosts(string $url)
1145         {
1146                 Logger::info('Fetch featured posts', ['contact' => $url]);
1147
1148                 $apcontact = APContact::getByURL($url);
1149                 if (empty($apcontact['featured'])) {
1150                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1151                         return;
1152                 }
1153
1154                 $pcid = Contact::getIdForURL($url, 0, false);
1155                 if (empty($pcid)) {
1156                         Logger::info('Contact not found', ['contact' => $url]);
1157                         return;
1158                 }
1159
1160                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1161                 if (!empty($posts)) {
1162                         $old_featured = array_column($posts, 'uri-id');
1163                 } else {
1164                         $old_featured = [];
1165                 }
1166
1167                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1168                 if (empty($featured)) {
1169                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1170
1171                         foreach ($old_featured as $uri_id) {
1172                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1173                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1174                         }
1175                         return;
1176                 }
1177
1178                 $new = 0;
1179                 $old = 0;
1180
1181                 foreach ($featured as $post) {
1182                         if (empty($post['id'])) {
1183                                 continue;
1184                         }
1185                         $id = Item::fetchByLink($post['id']);
1186                         if (!empty($id)) {
1187                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1188                                 if (!empty($item['uri-id'])) {
1189                                         if (!$item['featured']) {
1190                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1191                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1192                                                 $new++;
1193                                         } else {
1194                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1195                                                 $old++;
1196                                         }
1197
1198                                         $index = array_search($item['uri-id'], $old_featured);
1199                                         if (!($index === false)) {
1200                                                 unset($old_featured[$index]);
1201                                         }
1202                                 }
1203                         }
1204                 }
1205
1206                 foreach ($old_featured as $uri_id) {
1207                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1208                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1209                 }
1210
1211                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1212         }
1213
1214         public static function fetchCachedActivity(string $url, int $uid): array
1215         {
1216                 $cachekey = self::CACHEKEY_FETCH_ACTIVITY . $uid . ':' . $url;
1217                 $object = DI::cache()->get($cachekey);
1218
1219                 if (!is_null($object)) {
1220                         if (!empty($object)) {
1221                                 Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
1222                         } else {
1223                                 Logger::debug('Fetch from negative cache', ['url' => $url, 'uid' => $uid]);
1224                         }
1225                         return $object;
1226                 }
1227
1228                 $object = ActivityPub::fetchContent($url, $uid);
1229                 if (empty($object)) {
1230                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1231                         // We perform negative caching.
1232                         DI::cache()->set($cachekey, [], Duration::FIVE_MINUTES);
1233                         return [];
1234                 }
1235
1236                 if (empty($object['id'])) {
1237                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1238                         return [];
1239                 }
1240                 DI::cache()->set($cachekey, $object, Duration::FIVE_MINUTES);
1241
1242                 Logger::debug('Activity was fetched successfully', ['url' => $url, 'uid' => $uid]);
1243
1244                 return $object;
1245         }
1246
1247         /**
1248          * Fetches missing posts
1249          *
1250          * @param string     $url         message URL
1251          * @param array      $child       activity array with the child of this message
1252          * @param string     $relay_actor Relay actor
1253          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1254          * @return string fetched message URL
1255          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1256          * @throws \ImagickException
1257          */
1258         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL): string
1259         {
1260                 if (!empty($child['receiver'])) {
1261                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1262                 } else {
1263                         $uid = 0;
1264                 }
1265
1266                 $object = self::fetchCachedActivity($url, $uid);
1267                 if (empty($object)) {
1268                         return '';
1269                 }
1270
1271                 $signer = [];
1272
1273                 if (!empty($object['attributedTo'])) {
1274                         $attributed_to = $object['attributedTo'];
1275                         if (is_array($attributed_to)) {
1276                                 $compacted = JsonLD::compact($object);
1277                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1278                         }
1279                         $signer[] = $attributed_to;
1280                 }
1281
1282                 if (!empty($object['actor'])) {
1283                         $object_actor = $object['actor'];
1284                 } elseif (!empty($attributed_to)) {
1285                         $object_actor = $attributed_to;
1286                 } else {
1287                         // Shouldn't happen
1288                         $object_actor = '';
1289                 }
1290
1291                 $signer[] = $object_actor;
1292
1293                 if (!empty($child['author'])) {
1294                         $actor = $child['author'];
1295                         $signer[] = $actor;
1296                 } else {
1297                         $actor = $object_actor;
1298                 }
1299
1300                 if (!empty($object['published'])) {
1301                         $published = $object['published'];
1302                 } elseif (!empty($child['published'])) {
1303                         $published = $child['published'];
1304                 } else {
1305                         $published = DateTimeFormat::utcNow();
1306                 }
1307
1308                 $activity = [];
1309                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1310                 unset($object['@context']);
1311                 $activity['id'] = $object['id'];
1312                 $activity['to'] = $object['to'] ?? [];
1313                 $activity['cc'] = $object['cc'] ?? [];
1314                 $activity['actor'] = $actor;
1315                 $activity['object'] = $object;
1316                 $activity['published'] = $published;
1317                 $activity['type'] = 'Create';
1318
1319                 $ldactivity = JsonLD::compact($activity);
1320
1321                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 1;
1322
1323                 if (!empty($relay_actor)) {
1324                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1325                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1326                 } elseif (!empty($child['thread-completion'])) {
1327                         $ldactivity['thread-completion'] = $child['thread-completion'];
1328                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1329                 } else {
1330                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1331                         $ldactivity['completion-mode']   = $completion;
1332                 }
1333
1334                 if (!empty($child['type'])) {
1335                         $ldactivity['thread-children-type'] = $child['type'];
1336                 }
1337
1338                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1339                         return '';
1340                 }
1341
1342                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1343
1344                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1345
1346                 return $activity['id'];
1347         }
1348
1349         /**
1350          * Test if incoming relay messages should be accepted
1351          *
1352          * @param array $activity activity array
1353          * @param string $id      object ID
1354          * @return boolean true if message is accepted
1355          */
1356         private static function acceptIncomingMessage(array $activity, string $id): bool
1357         {
1358                 if (empty($activity['as:object'])) {
1359                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1360                         return true;
1361                 }
1362
1363                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1364                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1365                 if (Post::exists(['uri-id' => $uriid])) {
1366                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1367                         return true;
1368                 }
1369
1370                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1371                 $authorid = Contact::getIdForURL($attributed_to);
1372
1373                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1374
1375                 $messageTags = [];
1376                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1377                 if (!empty($tags)) {
1378                         foreach ($tags as $tag) {
1379                                 if ($tag['type'] != 'Hashtag') {
1380                                         continue;
1381                                 }
1382                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1383                         }
1384                 }
1385
1386                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1387         }
1388
1389         /**
1390          * perform a "follow" request
1391          *
1392          * @param array $activity
1393          * @return void
1394          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1395          * @throws \ImagickException
1396          */
1397         public static function followUser(array $activity)
1398         {
1399                 $uid = User::getIdForURL($activity['object_id']);
1400                 if (empty($uid)) {
1401                         Queue::remove($activity);
1402                         return;
1403                 }
1404
1405                 $owner = User::getOwnerDataById($uid);
1406                 if (empty($owner)) {
1407                         return;
1408                 }
1409
1410                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1411                 if (!empty($cid)) {
1412                         self::switchContact($cid);
1413                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1414                 }
1415
1416                 $item = [
1417                         'author-id' => Contact::getIdForURL($activity['actor']),
1418                         'author-link' => $activity['actor'],
1419                 ];
1420
1421                 // Ensure that the contact has got the right network type
1422                 self::switchContact($item['author-id']);
1423
1424                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1425                 if ($result === true) {
1426                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1427                 }
1428
1429                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1430                 if (empty($cid)) {
1431                         return;
1432                 }
1433
1434                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1435                         self::transmitPendingEvents($cid, $owner['uid']);
1436                 }
1437
1438                 if (empty($contact)) {
1439                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1440                 }
1441                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1442                 Queue::remove($activity);
1443         }
1444
1445         /**
1446          * Transmit pending events to the new follower
1447          *
1448          * @param integer $cid Contact id
1449          * @param integer $uid User id
1450          * @return void
1451          */
1452         private static function transmitPendingEvents(int $cid, int $uid)
1453         {
1454                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1455                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1456
1457                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1458                 while ($event = DBA::fetch($events)) {
1459                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1460                         if (empty($post)) {
1461                                 continue;
1462                         }
1463                         if (DI::config()->get('system', 'bulk_delivery')) {
1464                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1465                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1466                         } else {
1467                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1468                         }
1469                 }
1470         }
1471
1472         /**
1473          * Update the given profile
1474          *
1475          * @param array $activity
1476          * @throws \Exception
1477          */
1478         public static function updatePerson(array $activity)
1479         {
1480                 if (empty($activity['object_id'])) {
1481                         return;
1482                 }
1483
1484                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1485                 Contact::updateFromProbeByURL($activity['object_id']);
1486                 Queue::remove($activity);
1487         }
1488
1489         /**
1490          * Delete the given profile
1491          *
1492          * @param array $activity
1493          * @return void
1494          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1495          */
1496         public static function deletePerson(array $activity)
1497         {
1498                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1499                         Logger::info('Empty object id or actor.');
1500                         return;
1501                 }
1502
1503                 if ($activity['object_id'] != $activity['actor']) {
1504                         Logger::info('Object id does not match actor.');
1505                         return;
1506                 }
1507
1508                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1509                 while ($contact = DBA::fetch($contacts)) {
1510                         Contact::remove($contact['id']);
1511                 }
1512                 DBA::close($contacts);
1513
1514                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1515                 Queue::remove($activity);
1516         }
1517
1518         /**
1519          * Blocks the user by the contact
1520          *
1521          * @param array $activity
1522          * @return void
1523          * @throws \Exception
1524          */
1525         public static function blockAccount(array $activity)
1526         {
1527                 $cid = Contact::getIdForURL($activity['actor']);
1528                 if (empty($cid)) {
1529                         return;
1530                 }
1531
1532                 $uid = User::getIdForURL($activity['object_id']);
1533                 if (empty($uid)) {
1534                         return;
1535                 }
1536
1537                 Contact\User::setIsBlocked($cid, $uid, true);
1538
1539                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1540                 Queue::remove($activity);
1541         }
1542
1543         /**
1544          * Unblocks the user by the contact
1545          *
1546          * @param array $activity
1547          * @return void
1548          * @throws \Exception
1549          */
1550         public static function unblockAccount(array $activity)
1551         {
1552                 $cid = Contact::getIdForURL($activity['actor']);
1553                 if (empty($cid)) {
1554                         return;
1555                 }
1556
1557                 $uid = User::getIdForURL($activity['object_object']);
1558                 if (empty($uid)) {
1559                         return;
1560                 }
1561
1562                 Contact\User::setIsBlocked($cid, $uid, false);
1563
1564                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1565                 Queue::remove($activity);
1566         }
1567
1568         /**
1569          * Accept a follow request
1570          *
1571          * @param array $activity
1572          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1573          * @throws \ImagickException
1574          */
1575         public static function acceptFollowUser(array $activity)
1576         {
1577                 $uid = User::getIdForURL($activity['object_actor']);
1578                 if (empty($uid)) {
1579                         return;
1580                 }
1581
1582                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1583                 if (empty($cid)) {
1584                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1585                         return;
1586                 }
1587
1588                 self::switchContact($cid);
1589
1590                 $fields = ['pending' => false];
1591
1592                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1593                 if ($contact['rel'] == Contact::FOLLOWER) {
1594                         $fields['rel'] = Contact::FRIEND;
1595                 }
1596
1597                 $condition = ['id' => $cid];
1598                 Contact::update($fields, $condition);
1599                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1600                 Queue::remove($activity);
1601         }
1602
1603         /**
1604          * Reject a follow request
1605          *
1606          * @param array $activity
1607          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1608          * @throws \ImagickException
1609          */
1610         public static function rejectFollowUser(array $activity)
1611         {
1612                 $uid = User::getIdForURL($activity['object_actor']);
1613                 if (empty($uid)) {
1614                         return;
1615                 }
1616
1617                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1618                 if (empty($cid)) {
1619                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1620                         return;
1621                 }
1622
1623                 self::switchContact($cid);
1624
1625                 $contact = Contact::getById($cid, ['rel']);
1626                 if ($contact['rel'] == Contact::SHARING) {
1627                         Contact::remove($cid);
1628                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1629                 } elseif ($contact['rel'] == Contact::FRIEND) {
1630                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1631                 } else {
1632                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1633                 }
1634                 Queue::remove($activity);
1635         }
1636
1637         /**
1638          * Undo activity like "like" or "dislike"
1639          *
1640          * @param array $activity
1641          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1642          * @throws \ImagickException
1643          */
1644         public static function undoActivity(array $activity)
1645         {
1646                 if (empty($activity['object_id'])) {
1647                         return;
1648                 }
1649
1650                 if (empty($activity['object_actor'])) {
1651                         return;
1652                 }
1653
1654                 $author_id = Contact::getIdForURL($activity['object_actor']);
1655                 if (empty($author_id)) {
1656                         return;
1657                 }
1658
1659                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1660                 Queue::remove($activity);
1661         }
1662
1663         /**
1664          * Activity to remove a follower
1665          *
1666          * @param array $activity
1667          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1668          * @throws \ImagickException
1669          */
1670         public static function undoFollowUser(array $activity)
1671         {
1672                 $uid = User::getIdForURL($activity['object_object']);
1673                 if (empty($uid)) {
1674                         return;
1675                 }
1676
1677                 $owner = User::getOwnerDataById($uid);
1678                 if (empty($owner)) {
1679                         return;
1680                 }
1681
1682                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1683                 if (empty($cid)) {
1684                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1685                         return;
1686                 }
1687
1688                 self::switchContact($cid);
1689
1690                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1691                 if (!DBA::isResult($contact)) {
1692                         return;
1693                 }
1694
1695                 Contact::removeFollower($contact);
1696                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1697                 Queue::remove($activity);
1698         }
1699
1700         /**
1701          * Switches a contact to AP if needed
1702          *
1703          * @param integer $cid Contact ID
1704          * @return void
1705          * @throws \Exception
1706          */
1707         private static function switchContact(int $cid)
1708         {
1709                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1710                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1711                         return;
1712                 }
1713
1714                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1715                 Contact::updateFromProbe($cid);
1716         }
1717
1718         /**
1719          * Collects implicit mentions like:
1720          * - the author of the parent item
1721          * - all the mentioned conversants in the parent item
1722          *
1723          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1724          * @return array
1725          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1726          */
1727         private static function getImplicitMentionList(array $parent): array
1728         {
1729                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1730
1731                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1732
1733                 $implicit_mentions = [];
1734                 if (empty($parent_author['url'])) {
1735                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1736                 } else {
1737                         $implicit_mentions[] = $parent_author['url'];
1738                         $implicit_mentions[] = $parent_author['nurl'];
1739                         $implicit_mentions[] = $parent_author['alias'];
1740                 }
1741
1742                 if (!empty($parent['alias'])) {
1743                         $implicit_mentions[] = $parent['alias'];
1744                 }
1745
1746                 foreach ($parent_terms as $term) {
1747                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1748                         if (!empty($contact['url'])) {
1749                                 $implicit_mentions[] = $contact['url'];
1750                                 $implicit_mentions[] = $contact['nurl'];
1751                                 $implicit_mentions[] = $contact['alias'];
1752                         }
1753                 }
1754
1755                 return $implicit_mentions;
1756         }
1757
1758         /**
1759          * Strips from the body prepended implicit mentions
1760          *
1761          * @param string $body
1762          * @param array $parent
1763          * @return string
1764          */
1765         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
1766         {
1767                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1768                         return $body;
1769                 }
1770
1771                 $potential_mentions = self::getImplicitMentionList($parent);
1772
1773                 $kept_mentions = [];
1774
1775                 // Extract one prepended mention at a time from the body
1776                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1777                         if (!in_array($matches[2], $potential_mentions)) {
1778                                 $kept_mentions[] = $matches[1];
1779                         }
1780
1781                         $body = $matches[3];
1782                 }
1783
1784                 // Re-appending the kept mentions to the body after extraction
1785                 $kept_mentions[] = $body;
1786
1787                 return implode('', $kept_mentions);
1788         }
1789
1790         /**
1791          * Adds links to string mentions
1792          *
1793          * @param string $body
1794          * @param array  $tags
1795          * @return string
1796          */
1797         protected static function addMentionLinks(string $body, array $tags): string
1798         {
1799                 // This prevents links to be added again to Pleroma-style mention links
1800                 $body = self::normalizeMentionLinks($body);
1801
1802                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1803                         foreach ($tags as $tag) {
1804                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1805                                         continue;
1806                                 }
1807
1808                                 $hash = substr($tag['name'], 0, 1);
1809                                 $name = substr($tag['name'], 1);
1810                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1811                                         $hash = '';
1812                                         $name = $tag['name'];
1813                                 }
1814
1815                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1816                         }
1817
1818                         return $body;
1819                 });
1820
1821                 return $body;
1822         }
1823 }