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         const CACHEKEY_JUST_FETCHED   = 'processor:isJustFetched:';
  62         /**
  63          * Extracts the tag character (#, @, !) from mention links
  64          *
  65          * @param string $body
  66          * @return string
  67          */
  68         protected static function normalizeMentionLinks(string $body): string
  69         {
  70                 return preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  71         }
  72
  73         /**
  74          * Convert the language array into a language JSON
  75          *
  76          * @param array $languages
  77          * @return string language JSON
  78          */
  79         private static function processLanguages(array $languages): string
  80         {
  81                 $codes = array_keys($languages);
  82                 $lang = [];
  83                 foreach ($codes as $code) {
  84                         $lang[$code] = 1;
  85                 }
  86
  87                 if (empty($lang)) {
  88                         return '';
  89                 }
  90
  91                 return json_encode($lang);
  92         }
  93         /**
  94          * Replaces emojis in the body
  95          *
  96          * @param int $uri_id
  97          * @param string $body
  98          * @param array $emojis
  99          *
 100          * @return string with replaced emojis
 101          */
 102         private static function replaceEmojis(int $uri_id, string $body, array $emojis): string
 103         {
 104                 $body = strtr($body,
 105                         array_combine(
 106                                 array_column($emojis, 'name'),
 107                                 array_map(function ($emoji) {
 108                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 109                                 }, $emojis)
 110                         )
 111                 );
 112
 113                 // We store the emoji here to be able to avoid storing it in the media
 114                 foreach ($emojis as $emoji) {
 115                         Post\Link::getByLink($uri_id, $emoji['href']);
 116                 }
 117                 return $body;
 118         }
 119
 120         /**
 121          * Store attached media files in the post-media table
 122          *
 123          * @param int $uriid
 124          * @param array $attachment
 125          * @return void
 126          */
 127         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 128         {
 129                 if (empty($attachment['url'])) {
 130                         return;
 131                 }
 132
 133                 $data = ['uri-id' => $uriid];
 134                 $data['type'] = Post\Media::UNKNOWN;
 135                 $data['url'] = $attachment['url'];
 136                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 137                 $data['height'] = $attachment['height'] ?? null;
 138                 $data['width'] = $attachment['width'] ?? null;
 139                 $data['size'] = $attachment['size'] ?? null;
 140                 $data['preview'] = $attachment['image'] ?? null;
 141                 $data['description'] = $attachment['name'] ?? null;
 142
 143                 Post\Media::insert($data);
 144         }
 145
 146         /**
 147          * Stire attachment data
 148          *
 149          * @param array   $activity
 150          * @param array   $item
 151          */
 152         private static function storeAttachments(array $activity, array $item)
 153         {
 154                 if (empty($activity['attachments'])) {
 155                         return;
 156                 }
 157
 158                 foreach ($activity['attachments'] as $attach) {
 159                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 160                 }
 161         }
 162
 163         /**
 164          * Store attachment data
 165          *
 166          * @param array   $activity
 167          * @param array   $item
 168          */
 169         private static function storeQuestion(array $activity, array $item)
 170         {
 171                 if (empty($activity['question'])) {
 172                         return;
 173                 }
 174                 $question = ['multiple' => $activity['question']['multiple']];
 175
 176                 if (!empty($activity['question']['voters'])) {
 177                         $question['voters'] = $activity['question']['voters'];
 178                 }
 179
 180                 if (!empty($activity['question']['end-time'])) {
 181                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 182                 }
 183
 184                 Post\Question::update($item['uri-id'], $question);
 185
 186                 foreach ($activity['question']['options'] as $key => $option) {
 187                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 188                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 189                 }
 190
 191                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 192         }
 193
 194         /**
 195          * Updates a message
 196          *
 197          * @param array      $activity   Activity array
 198          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 199          * @throws \ImagickException
 200          */
 201         public static function updateItem(array $activity)
 202         {
 203                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 204                 if (!DBA::isResult($item)) {
 205                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 206                         $item = self::createItem($activity);
 207                         if (empty($item)) {
 208                                 return;
 209                         }
 210
 211                         self::postItem($activity, $item);
 212                         return;
 213                 }
 214
 215                 $item['changed'] = DateTimeFormat::utcNow();
 216                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 217
 218                 $item = self::processContent($activity, $item);
 219                 if (empty($item)) {
 220                         return;
 221                 }
 222
 223                 self::storeAttachments($activity, $item);
 224                 self::storeQuestion($activity, $item);
 225
 226                 Post\History::add($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['author']) && empty($activity['actor'])) {
 304                         Logger::notice('Missing author and actor. We quit here.', ['activity' => $activity]);
 305                         return [];
 306                 }
 307
 308                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 309                         if (self::hasJustBeenFetched($activity['reply-to-id'])) {
 310                                 Logger::notice('We just have tried to fetch this activity. We don\'t try it again.', ['parent' => $activity['reply-to-id']]);
 311                                 $fetch_by_worker = false;
 312                                 if (empty($conversation)) {
 313                                         return [];
 314                                 }
 315                         } else {
 316                                 $recursion_depth = $activity['recursion-depth'] ?? 0;
 317                                 Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 318                                 if ($recursion_depth < DI::config()->get('system', 'max_recursion_depth')) {
 319                                         $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 320                                         $fetch_by_worker = empty($result);
 321                                         if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 322                                                 if (!empty($activity['entry-id'])) {
 323                                                         Queue::deleteById($activity['entry-id']);
 324                                                 }
 325                                                 if (empty($conversation)) {
 326                                                         return [];
 327                                                 }
 328                                         }
 329                                 } else {
 330                                         Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 331                                         $fetch_by_worker = true;
 332                                 }
 333                         }
 334
 335                         if ($fetch_by_worker && Queue::hasWorker($activity)) {
 336                                 Logger::notice('There is already a worker task to fetch the post.', ['id' => $activity['id'], 'parent' => $activity['reply-to-id']]);
 337                                 $fetch_by_worker = false;
 338                                 if (empty($conversation)) {
 339                                         return [];
 340                                 }
 341                         }
 342
 343                         if ($fetch_by_worker && DI::config()->get('system', 'fetch_by_worker')) {
 344                                 Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 345                                 $activity['recursion-depth'] = 0;
 346                                 if (!Fetch::hasWorker($activity['reply-to-id'])) {
 347                                         Fetch::add($activity['reply-to-id']);
 348                                         $wid = Worker::add(PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 349                                         Fetch::setWorkerId($activity['reply-to-id'], $wid);
 350                                         Queue::setWorkerId($activity, $wid);
 351                                 } else {
 352                                         Logger::debug('Activity will already be fetched via a worker.', ['url' => $activity['reply-to-id']]);
 353                                 }
 354                                 if (empty($conversation)) {
 355                                         return [];
 356                                 }
 357                         } elseif (!empty($result)) {
 358                                 if (($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 359                                         $item['thr-parent'] = $result;
 360                                 }
 361                         }
 362                 }
 363
 364                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 365
 366                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 367                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 368                         return [];
 369                 }
 370
 371                 $item['network'] = Protocol::ACTIVITYPUB;
 372                 $item['author-link'] = $activity['author'];
 373                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 374                 $item['owner-link'] = $activity['actor'];
 375                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 376
 377                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 378                         $item['private'] = Item::UNLISTED;
 379                 } elseif (in_array(0, $activity['receiver'])) {
 380                         $item['private'] = Item::PUBLIC;
 381                 } else {
 382                         $item['private'] = Item::PRIVATE;
 383                 }
 384
 385                 if (!empty($activity['raw'])) {
 386                         $item['source'] = $activity['raw'];
 387                 }
 388
 389                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 390
 391                 if (isset($activity['push'])) {
 392                         $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 393                 }
 394
 395                 if (!empty($activity['from-relay'])) {
 396                         $item['direction'] = Conversation::RELAY;
 397                 }
 398
 399                 if ($activity['object_type'] == 'as:Article') {
 400                         $item['post-type'] = Item::PT_ARTICLE;
 401                 } elseif ($activity['object_type'] == 'as:Audio') {
 402                         $item['post-type'] = Item::PT_AUDIO;
 403                 } elseif ($activity['object_type'] == 'as:Document') {
 404                         $item['post-type'] = Item::PT_DOCUMENT;
 405                 } elseif ($activity['object_type'] == 'as:Event') {
 406                         $item['post-type'] = Item::PT_EVENT;
 407                 } elseif ($activity['object_type'] == 'as:Image') {
 408                         $item['post-type'] = Item::PT_IMAGE;
 409                 } elseif ($activity['object_type'] == 'as:Page') {
 410                         $item['post-type'] = Item::PT_PAGE;
 411                 } elseif ($activity['object_type'] == 'as:Question') {
 412                         $item['post-type'] = Item::PT_POLL;
 413                 } elseif ($activity['object_type'] == 'as:Video') {
 414                         $item['post-type'] = Item::PT_VIDEO;
 415                 } else {
 416                         $item['post-type'] = Item::PT_NOTE;
 417                 }
 418
 419                 $item['isForum'] = false;
 420
 421                 if (!empty($activity['thread-completion'])) {
 422                         if ($activity['thread-completion'] != $item['owner-id']) {
 423                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 424                                 $item['causer-link'] = $actor['url'];
 425                                 $item['causer-id'] = $activity['thread-completion'];
 426                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 427                         } else {
 428                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 429                                 $item['causer-link'] = $item['owner-link'];
 430                                 $item['causer-id']   = $item['owner-id'];
 431                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 432                         }
 433
 434                         $item['owner-link'] = $item['author-link'];
 435                         $item['owner-id'] = $item['author-id'];
 436                 } else {
 437                         $actor = APContact::getByURL($item['owner-link'], false);
 438                         $item['isForum'] = ($actor['type'] == 'Group');
 439                 }
 440
 441                 $item['uri'] = $activity['id'];
 442
 443                 if (empty($activity['published']) || empty($activity['updated'])) {
 444                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 445                 }
 446
 447                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 448                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 449                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 450                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 451
 452                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 453                 if (empty($item['uri-id'])) {
 454                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 455                         return [];
 456                 }
 457
 458                 $item = self::processContent($activity, $item);
 459                 if (empty($item)) {
 460                         Logger::info('Message was not processed');
 461                         return [];
 462                 }
 463
 464                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 465
 466                 self::storeAttachments($activity, $item);
 467                 self::storeQuestion($activity, $item);
 468
 469                 // We received the post via AP, so we set the protocol of the server to AP
 470                 $contact = Contact::getById($item['author-id'], ['gsid']);
 471                 if (!empty($contact['gsid'])) {
 472                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 473                 }
 474
 475                 if ($item['author-id'] != $item['owner-id']) {
 476                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 477                         if (!empty($contact['gsid'])) {
 478                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 479                         }
 480                 }
 481
 482                 return $item;
 483         }
 484
 485         /**
 486          * Check if a given activity has recently been fetched
 487          *
 488          * @param string $url
 489          * @return boolean
 490          */
 491         private static function hasJustBeenFetched(string $url): bool
 492         {
 493                 $cachekey = self::CACHEKEY_JUST_FETCHED . $url;
 494                 $time = DI::cache()->get($cachekey);
 495                 if (is_null($time)) {
 496                         DI::cache()->set($cachekey, time(), Duration::FIVE_MINUTES);
 497                         return false;
 498                 }
 499                 return ($time + 300) > time();
 500         }
 501
 502         /**
 503          * Check if a given activity is no longer available
 504          *
 505          * @param string $url
 506          *
 507          * @return boolean
 508          */
 509         public static function isActivityGone(string $url): bool
 510         {
 511                 $curlResult = HTTPSignature::fetchRaw($url, 0);
 512
 513                 if (Network::isUrlBlocked($url)) {
 514                         return true;
 515                 }
 516
 517                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 518                 if (in_array($curlResult->getReturnCode(), [404])) {
 519                         return true;
 520                 }
 521
 522                 $object = json_decode($curlResult->getBody(), true);
 523                 if (!empty($object)) {
 524                         $activity = JsonLD::compact($object);
 525                         if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 526                                 return true;
 527                         }
 528                 }
 529
 530                 return false;
 531         }
 532         /**
 533          * Delete items
 534          *
 535          * @param array $activity
 536          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 537          * @throws \ImagickException
 538          */
 539         public static function deleteItem(array $activity)
 540         {
 541                 $owner = Contact::getIdForURL($activity['actor']);
 542
 543                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 544                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 545                 Queue::remove($activity);
 546         }
 547
 548         /**
 549          * Prepare the item array for an activity
 550          *
 551          * @param array $activity Activity array
 552          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 553          * @throws \ImagickException
 554          */
 555         public static function addTag(array $activity)
 556         {
 557                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 558                         return;
 559                 }
 560
 561                 foreach ($activity['receiver'] as $receiver) {
 562                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 563                         if (!DBA::isResult($item)) {
 564                                 // We don't fetch missing content for this purpose
 565                                 continue;
 566                         }
 567
 568                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 569                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 570                                 continue;
 571                         }
 572
 573                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 574                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 575                 }
 576         }
 577
 578         /**
 579          * Prepare the item array for an activity
 580          *
 581          * @param array      $activity   Activity array
 582          * @param string     $verb       Activity verb
 583          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 584          * @throws \ImagickException
 585          */
 586         public static function createActivity(array $activity, string $verb)
 587         {
 588                 $activity['reply-to-id'] = $activity['object_id'];
 589                 $item = self::createItem($activity);
 590                 if (empty($item)) {
 591                         return;
 592                 }
 593
 594                 $item['verb'] = $verb;
 595                 $item['thr-parent'] = $activity['object_id'];
 596                 $item['gravity'] = GRAVITY_ACTIVITY;
 597                 unset($item['post-type']);
 598                 $item['object-type'] = Activity\ObjectType::NOTE;
 599
 600                 if (!empty($activity['content'])) {
 601                         $item['body'] = HTML::toBBCode($activity['content']);
 602                 }
 603
 604                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 605
 606                 self::postItem($activity, $item);
 607         }
 608
 609         /**
 610          * Fetch the Uri-Id of a post for the "featured" collection
 611          *
 612          * @param array $activity
 613          * @return null|int
 614          */
 615         private static function getUriIdForFeaturedCollection(array $activity)
 616         {
 617                 $actor = APContact::getByURL($activity['actor']);
 618                 if (empty($actor)) {
 619                         return null;
 620                 }
 621
 622                 // Refetch the account when the "featured" collection is missing.
 623                 // This can be removed in a future version (end of 2022 should be good).
 624                 if (empty($actor['featured'])) {
 625                         $actor = APContact::getByURL($activity['actor'], true);
 626                         if (empty($actor)) {
 627                                 return null;
 628                         }
 629                 }
 630
 631                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 632                 if (empty($parent['uri-id'])) {
 633                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 634                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 635                         }
 636                 }
 637
 638                 if (!empty($parent['uri-id'])) {
 639                         return $parent['uri-id'];
 640                 }
 641
 642                 return null;
 643         }
 644
 645         /**
 646          * Add a post to the "Featured" collection
 647          *
 648          * @param array $activity
 649          */
 650         public static function addToFeaturedCollection(array $activity)
 651         {
 652                 $uriid = self::getUriIdForFeaturedCollection($activity);
 653                 if (empty($uriid)) {
 654                         return;
 655                 }
 656
 657                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 658
 659                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 660                 Queue::remove($activity);
 661         }
 662
 663         /**
 664          * Remove a post to the "Featured" collection
 665          *
 666          * @param array $activity
 667          */
 668         public static function removeFromFeaturedCollection(array $activity)
 669         {
 670                 $uriid = self::getUriIdForFeaturedCollection($activity);
 671                 if (empty($uriid)) {
 672                         return;
 673                 }
 674
 675                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 676
 677                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 678                 Queue::remove($activity);
 679         }
 680
 681         /**
 682          * Create an event
 683          *
 684          * @param array $activity Activity array
 685          * @param array $item
 686          *
 687          * @return int event id
 688          * @throws \Exception
 689          */
 690         public static function createEvent(array $activity, array $item): int
 691         {
 692                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 693                 $event['desc']      = HTML::toBBCode($activity['content']);
 694                 if (!empty($activity['start-time'])) {
 695                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 696                 }
 697                 if (!empty($activity['end-time'])) {
 698                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 699                 }
 700                 $event['nofinish']  = empty($event['finish']);
 701                 $event['location']  = $activity['location'];
 702                 $event['cid']       = $item['contact-id'];
 703                 $event['uid']       = $item['uid'];
 704                 $event['uri']       = $item['uri'];
 705                 $event['edited']    = $item['edited'];
 706                 $event['private']   = $item['private'];
 707                 $event['guid']      = $item['guid'];
 708                 $event['plink']     = $item['plink'];
 709                 $event['network']   = $item['network'];
 710                 $event['protocol']  = $item['protocol'];
 711                 $event['direction'] = $item['direction'];
 712                 $event['source']    = $item['source'];
 713
 714                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 715                 if (DBA::isResult($ev)) {
 716                         $event['id'] = $ev['id'];
 717                 }
 718
 719                 $event_id = Event::store($event);
 720
 721                 Logger::info('Event was stored', ['id' => $event_id]);
 722
 723                 return $event_id;
 724         }
 725
 726         /**
 727          * Process the content
 728          *
 729          * @param array $activity Activity array
 730          * @param array $item
 731          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 732          * @throws \Exception
 733          */
 734         private static function processContent(array $activity, array $item)
 735         {
 736                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 737                         $item['title'] = strip_tags($activity['name']);
 738                         $content = Markdown::toBBCode($activity['content']);
 739                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 740                         $item['title'] = $activity['name'];
 741                         $content = $activity['content'];
 742                 } else {
 743                         // By default assume "text/html"
 744                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 745                         $content = HTML::toBBCode($activity['content'] ?? '');
 746                 }
 747
 748                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 749
 750                 if (!empty($activity['languages'])) {
 751                         $item['language'] = self::processLanguages($activity['languages']);
 752                 }
 753
 754                 if (!empty($activity['emojis'])) {
 755                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 756                 }
 757
 758                 $content = self::addMentionLinks($content, $activity['tags']);
 759
 760                 if (!empty($activity['source'])) {
 761                         $item['body'] = $activity['source'];
 762                         $item['raw-body'] = $content;
 763                         $item['body'] = Item::improveSharedDataInBody($item);
 764                 } else {
 765                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 766                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 767                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 768                                 if (!DBA::isResult($parent)) {
 769                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 770                                         return false;
 771                                 }
 772                                 if (($item['private'] == Item::PRIVATE) && ($parent['private'] != Item::PRIVATE)) {
 773                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 774                                         return false;
 775                                 }
 776
 777                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 778                         }
 779                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 780                         $item['raw-body'] = $item['body'] = $content;
 781                 }
 782
 783                 self::storeFromBody($item);
 784                 self::storeTags($item['uri-id'], $activity['tags']);
 785
 786                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 787
 788                 $item['location'] = $activity['location'];
 789
 790                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 791                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 792                 }
 793
 794                 $item['app'] = $activity['generator'];
 795
 796                 return $item;
 797         }
 798
 799         /**
 800          * Store hashtags and mentions
 801          *
 802          * @param array $item
 803          */
 804         private static function storeFromBody(array $item)
 805         {
 806                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 807                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 808
 809                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 810         }
 811
 812         /**
 813          * Generate a GUID out of an URL of an ActivityPub post.
 814          *
 815          * @param string $url message URL
 816          * @return string with GUID
 817          */
 818         private static function getGUIDByURL(string $url): string
 819         {
 820                 $parsed = parse_url($url);
 821
 822                 $host_hash = hash('crc32', $parsed['host']);
 823
 824                 unset($parsed["scheme"]);
 825                 unset($parsed["host"]);
 826
 827                 $path = implode("/", $parsed);
 828
 829                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 830         }
 831
 832         /**
 833          * Checks if an incoming message is wanted
 834          *
 835          * @param array $activity
 836          * @param array $item
 837          * @return boolean Is the message wanted?
 838          */
 839         private static function isSolicitedMessage(array $activity, array $item): bool
 840         {
 841                 // The checks are split to improve the support when searching why a message was accepted.
 842                 if (count($activity['receiver']) != 1) {
 843                         // The message has more than one receiver, so it is wanted.
 844                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 845                         return true;
 846                 }
 847
 848                 if ($item['private'] == Item::PRIVATE) {
 849                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 850                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 851                         return true;
 852                 }
 853
 854                 if (!empty($activity['from-relay'])) {
 855                         // We check relay posts at another place. When it arrived here, the message is already checked.
 856                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 857                         return true;
 858                 }
 859
 860                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 861                         // Manual completions and completions caused by reshares are allowed without any further checks.
 862                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 863                         return true;
 864                 }
 865
 866                 if ($item['gravity'] != GRAVITY_PARENT) {
 867                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 868                         // This can possibly be improved in the future.
 869                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 870                         return true;
 871                 }
 872
 873                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 874                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 875                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 876                         return true;
 877                 } else {
 878                         return false;
 879                 }
 880         }
 881
 882         /**
 883          * Creates an item post
 884          *
 885          * @param array $activity Activity data
 886          * @param array $item     item array
 887          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 888          * @throws \ImagickException
 889          */
 890         public static function postItem(array $activity, array $item)
 891         {
 892                 if (empty($item)) {
 893                         return;
 894                 }
 895
 896                 $stored = false;
 897                 $success = false;
 898                 ksort($activity['receiver']);
 899
 900                 if (!self::isSolicitedMessage($activity, $item)) {
 901                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 902                         return;
 903                 }
 904
 905                 foreach ($activity['receiver'] as $receiver) {
 906                         if ($receiver == -1) {
 907                                 continue;
 908                         }
 909
 910                         $item['uid'] = $receiver;
 911
 912                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 913                         switch($type) {
 914                                 case Receiver::TARGET_TO:
 915                                         $item['post-reason'] = Item::PR_TO;
 916                                         break;
 917                                 case Receiver::TARGET_CC:
 918                                         $item['post-reason'] = Item::PR_CC;
 919                                         break;
 920                                 case Receiver::TARGET_BTO:
 921                                         $item['post-reason'] = Item::PR_BTO;
 922                                         break;
 923                                 case Receiver::TARGET_BCC:
 924                                         $item['post-reason'] = Item::PR_BCC;
 925                                         break;
 926                                 case Receiver::TARGET_FOLLOWER:
 927                                         $item['post-reason'] = Item::PR_FOLLOWER;
 928                                         break;
 929                                 case Receiver::TARGET_ANSWER:
 930                                         $item['post-reason'] = Item::PR_COMMENT;
 931                                         break;
 932                                 case Receiver::TARGET_GLOBAL:
 933                                         $item['post-reason'] = Item::PR_GLOBAL;
 934                                         break;
 935                                 default:
 936                                         $item['post-reason'] = Item::PR_NONE;
 937                         }
 938
 939                         if (!empty($activity['from-relay'])) {
 940                                 $item['post-reason'] = Item::PR_RELAY;
 941                         } elseif (!empty($activity['thread-completion'])) {
 942                                 $item['post-reason'] = Item::PR_FETCHED;
 943                         } elseif (in_array($item['post-reason'], [Item::PR_GLOBAL, Item::PR_NONE]) && !empty($activity['push'])) {
 944                                 $item['post-reason'] = Item::PR_PUSHED;
 945                         }
 946
 947                         if ($item['isForum'] ?? false) {
 948                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 949                         } else {
 950                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 951                         }
 952
 953                         if (($receiver != 0) && empty($item['contact-id'])) {
 954                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 955                         }
 956
 957                         if (!empty($activity['directmessage'])) {
 958                                 self::postMail($activity, $item);
 959                                 continue;
 960                         }
 961
 962                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 963                                 if ($item['post-reason'] == Item::PR_BCC) {
 964                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 965                                         continue;
 966                                 }
 967
 968                                 if (
 969                                         !empty($activity['thread-children-type'])
 970                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 971                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 972                                 ) {
 973                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 974                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 975                                         continue;
 976                                 }
 977                         }
 978
 979                         $is_forum = false;
 980
 981                         if ($receiver != 0) {
 982                                 $user = User::getById($receiver, ['account-type']);
 983                                 if (!empty($user['account-type'])) {
 984                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 985                                 }
 986                         }
 987
 988                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 989                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 990
 991                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 992                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 993                                 }
 994
 995                                 if ($skip) {
 996                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 997                                         continue;
 998                                 }
 999
1000                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
1001                         }
1002
1003                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
1004                                 $event_id = self::createEvent($activity, $item);
1005
1006                                 $item = Event::getItemArrayForImportedId($event_id, $item);
1007                         }
1008
1009                         $item_id = Item::insert($item);
1010                         if ($item_id) {
1011                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
1012                                 $success = true;
1013                         } else {
1014                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
1015                         }
1016
1017                         if ($item['uid'] == 0) {
1018                                 $stored = $item_id;
1019                         }
1020                 }
1021
1022                 Queue::remove($activity);
1023
1024                 if ($success && Queue::hasChildren($item['uri'])) {
1025                         Worker::add(PRIORITY_HIGH, 'ProcessReplyByUri', $item['uri']);
1026                 }
1027
1028                 // Store send a follow request for every reshare - but only when the item had been stored
1029                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
1030                         $author = APContact::getByURL($item['owner-link'], false);
1031                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
1032                         if ($author['type'] != 'Group') {
1033                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
1034                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
1035                         }
1036                 }
1037         }
1038
1039         /**
1040          * Store tags and mentions into the tag table
1041          *
1042          * @param integer $uriid
1043          * @param array $tags
1044          */
1045         private static function storeTags(int $uriid, array $tags = null)
1046         {
1047                 foreach ($tags as $tag) {
1048                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1049                                 continue;
1050                         }
1051
1052                         $hash = substr($tag['name'], 0, 1);
1053
1054                         if ($tag['type'] == 'Mention') {
1055                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1056                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1057                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1058                                         $tag['name'] = substr($tag['name'], 1);
1059                                 }
1060                                 $type = Tag::IMPLICIT_MENTION;
1061
1062                                 if (!empty($tag['href'])) {
1063                                         $apcontact = APContact::getByURL($tag['href']);
1064                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1065                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1066                                         }
1067                                 }
1068                         } elseif ($tag['type'] == 'Hashtag') {
1069                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1070                                         $tag['name'] = substr($tag['name'], 1);
1071                                 }
1072                                 $type = Tag::HASHTAG;
1073                         }
1074
1075                         if (empty($tag['name'])) {
1076                                 continue;
1077                         }
1078
1079                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1080                 }
1081         }
1082
1083         public static function storeReceivers(int $uriid, array $receivers)
1084         {
1085                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
1086                         if (!empty($receivers[$element])) {
1087                                 foreach ($receivers[$element] as $receiver) {
1088                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1089                                                 $name = Receiver::PUBLIC_COLLECTION;
1090                                         } else {
1091                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
1092                                         }
1093
1094                                         $target = Tag::getTargetType($receiver);
1095                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1096                                         Tag::store($uriid, $type, $name, $receiver, $target);
1097                                 }
1098                         }
1099                 }
1100         }
1101
1102         /**
1103          * Creates an mail post
1104          *
1105          * @param array $activity Activity data
1106          * @param array $item     item array
1107          * @return int|bool New mail table row id or false on error
1108          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1109          */
1110         private static function postMail(array $activity, array $item)
1111         {
1112                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1113                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1114                         return false;
1115                 }
1116
1117                 Logger::info('Direct Message', $item);
1118
1119                 $msg = [];
1120                 $msg['uid'] = $item['uid'];
1121
1122                 $msg['contact-id'] = $item['contact-id'];
1123
1124                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1125                 $msg['from-name'] = $contact['name'];
1126                 $msg['from-url'] = $contact['url'];
1127                 $msg['from-photo'] = $contact['photo'];
1128
1129                 $msg['uri'] = $item['uri'];
1130                 $msg['created'] = $item['created'];
1131
1132                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1133                 if (DBA::isResult($parent)) {
1134                         $msg['parent-uri'] = $parent['parent-uri'];
1135                         $msg['title'] = $parent['title'];
1136                 } else {
1137                         $msg['parent-uri'] = $item['thr-parent'];
1138
1139                         if (!empty($item['title'])) {
1140                                 $msg['title'] = $item['title'];
1141                         } elseif (!empty($item['content-warning'])) {
1142                                 $msg['title'] = $item['content-warning'];
1143                         } else {
1144                                 // Trying to generate a title out of the body
1145                                 $title = $item['body'];
1146
1147                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1148                                         $title = $matches[3];
1149                                 }
1150
1151                                 $title = trim(BBCode::toPlaintext($title));
1152
1153                                 if (strlen($title) > 20) {
1154                                         $title = substr($title, 0, 20) . '...';
1155                                 }
1156
1157                                 $msg['title'] = $title;
1158                         }
1159                 }
1160                 $msg['body'] = $item['body'];
1161
1162                 return Mail::insert($msg);
1163         }
1164
1165         /**
1166          * Fetch featured posts from a contact with the given url
1167          *
1168          * @param string $url
1169          * @return void
1170          */
1171         public static function fetchFeaturedPosts(string $url)
1172         {
1173                 Logger::info('Fetch featured posts', ['contact' => $url]);
1174
1175                 $apcontact = APContact::getByURL($url);
1176                 if (empty($apcontact['featured'])) {
1177                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1178                         return;
1179                 }
1180
1181                 $pcid = Contact::getIdForURL($url, 0, false);
1182                 if (empty($pcid)) {
1183                         Logger::info('Contact not found', ['contact' => $url]);
1184                         return;
1185                 }
1186
1187                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1188                 if (!empty($posts)) {
1189                         $old_featured = array_column($posts, 'uri-id');
1190                 } else {
1191                         $old_featured = [];
1192                 }
1193
1194                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1195                 if (empty($featured)) {
1196                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1197
1198                         foreach ($old_featured as $uri_id) {
1199                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1200                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1201                         }
1202                         return;
1203                 }
1204
1205                 $new = 0;
1206                 $old = 0;
1207
1208                 foreach ($featured as $post) {
1209                         if (empty($post['id'])) {
1210                                 continue;
1211                         }
1212                         $id = Item::fetchByLink($post['id']);
1213                         if (!empty($id)) {
1214                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1215                                 if (!empty($item['uri-id'])) {
1216                                         if (!$item['featured']) {
1217                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1218                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1219                                                 $new++;
1220                                         } else {
1221                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1222                                                 $old++;
1223                                         }
1224
1225                                         $index = array_search($item['uri-id'], $old_featured);
1226                                         if (!($index === false)) {
1227                                                 unset($old_featured[$index]);
1228                                         }
1229                                 }
1230                         }
1231                 }
1232
1233                 foreach ($old_featured as $uri_id) {
1234                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1235                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1236                 }
1237
1238                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1239         }
1240
1241         public static function fetchCachedActivity(string $url, int $uid): array
1242         {
1243                 $cachekey = self::CACHEKEY_FETCH_ACTIVITY . $uid . ':' . $url;
1244                 $object = DI::cache()->get($cachekey);
1245
1246                 if (!is_null($object)) {
1247                         if (!empty($object)) {
1248                                 Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
1249                         } else {
1250                                 Logger::debug('Fetch from negative cache', ['url' => $url, 'uid' => $uid]);
1251                         }
1252                         return $object;
1253                 }
1254
1255                 $object = ActivityPub::fetchContent($url, $uid);
1256                 if (empty($object)) {
1257                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1258                         // We perform negative caching.
1259                         DI::cache()->set($cachekey, [], Duration::FIVE_MINUTES);
1260                         return [];
1261                 }
1262
1263                 if (empty($object['id'])) {
1264                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1265                         return [];
1266                 }
1267                 DI::cache()->set($cachekey, $object, Duration::FIVE_MINUTES);
1268
1269                 Logger::debug('Activity was fetched successfully', ['url' => $url, 'uid' => $uid]);
1270
1271                 return $object;
1272         }
1273
1274         /**
1275          * Fetches missing posts
1276          *
1277          * @param string     $url         message URL
1278          * @param array      $child       activity array with the child of this message
1279          * @param string     $relay_actor Relay actor
1280          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1281          * @return string fetched message URL
1282          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1283          * @throws \ImagickException
1284          */
1285         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL): string
1286         {
1287                 if (!empty($child['receiver'])) {
1288                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1289                 } else {
1290                         $uid = 0;
1291                 }
1292
1293                 $object = self::fetchCachedActivity($url, $uid);
1294                 if (empty($object)) {
1295                         return '';
1296                 }
1297
1298                 $signer = [];
1299
1300                 if (!empty($object['attributedTo'])) {
1301                         $attributed_to = $object['attributedTo'];
1302                         if (is_array($attributed_to)) {
1303                                 $compacted = JsonLD::compact($object);
1304                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1305                         }
1306                         $signer[] = $attributed_to;
1307                 }
1308
1309                 if (!empty($object['actor'])) {
1310                         $object_actor = $object['actor'];
1311                 } elseif (!empty($attributed_to)) {
1312                         $object_actor = $attributed_to;
1313                 } else {
1314                         // Shouldn't happen
1315                         $object_actor = '';
1316                 }
1317
1318                 $signer[] = $object_actor;
1319
1320                 if (!empty($child['author'])) {
1321                         $actor = $child['author'];
1322                         $signer[] = $actor;
1323                 } else {
1324                         $actor = $object_actor;
1325                 }
1326
1327                 if (!empty($object['published'])) {
1328                         $published = $object['published'];
1329                 } elseif (!empty($child['published'])) {
1330                         $published = $child['published'];
1331                 } else {
1332                         $published = DateTimeFormat::utcNow();
1333                 }
1334
1335                 $activity = [];
1336                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1337                 unset($object['@context']);
1338                 $activity['id'] = $object['id'];
1339                 $activity['to'] = $object['to'] ?? [];
1340                 $activity['cc'] = $object['cc'] ?? [];
1341                 $activity['actor'] = $actor;
1342                 $activity['object'] = $object;
1343                 $activity['published'] = $published;
1344                 $activity['type'] = 'Create';
1345
1346                 $ldactivity = JsonLD::compact($activity);
1347
1348                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 1;
1349
1350                 if (!empty($relay_actor)) {
1351                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1352                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1353                 } elseif (!empty($child['thread-completion'])) {
1354                         $ldactivity['thread-completion'] = $child['thread-completion'];
1355                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1356                 } else {
1357                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1358                         $ldactivity['completion-mode']   = $completion;
1359                 }
1360
1361                 if (!empty($child['type'])) {
1362                         $ldactivity['thread-children-type'] = $child['type'];
1363                 }
1364
1365                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1366                         return '';
1367                 }
1368
1369                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1370
1371                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1372
1373                 return $activity['id'];
1374         }
1375
1376         /**
1377          * Test if incoming relay messages should be accepted
1378          *
1379          * @param array $activity activity array
1380          * @param string $id      object ID
1381          * @return boolean true if message is accepted
1382          */
1383         private static function acceptIncomingMessage(array $activity, string $id): bool
1384         {
1385                 if (empty($activity['as:object'])) {
1386                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1387                         return true;
1388                 }
1389
1390                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1391                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1392                 if (Post::exists(['uri-id' => $uriid])) {
1393                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1394                         return true;
1395                 }
1396
1397                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1398                 $authorid = Contact::getIdForURL($attributed_to);
1399
1400                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1401
1402                 $messageTags = [];
1403                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1404                 if (!empty($tags)) {
1405                         foreach ($tags as $tag) {
1406                                 if ($tag['type'] != 'Hashtag') {
1407                                         continue;
1408                                 }
1409                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1410                         }
1411                 }
1412
1413                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1414         }
1415
1416         /**
1417          * perform a "follow" request
1418          *
1419          * @param array $activity
1420          * @return void
1421          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1422          * @throws \ImagickException
1423          */
1424         public static function followUser(array $activity)
1425         {
1426                 $uid = User::getIdForURL($activity['object_id']);
1427                 if (empty($uid)) {
1428                         Queue::remove($activity);
1429                         return;
1430                 }
1431
1432                 $owner = User::getOwnerDataById($uid);
1433                 if (empty($owner)) {
1434                         return;
1435                 }
1436
1437                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1438                 if (!empty($cid)) {
1439                         self::switchContact($cid);
1440                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1441                 }
1442
1443                 $item = [
1444                         'author-id' => Contact::getIdForURL($activity['actor']),
1445                         'author-link' => $activity['actor'],
1446                 ];
1447
1448                 // Ensure that the contact has got the right network type
1449                 self::switchContact($item['author-id']);
1450
1451                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1452                 if ($result === true) {
1453                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1454                 }
1455
1456                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1457                 if (empty($cid)) {
1458                         return;
1459                 }
1460
1461                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1462                         self::transmitPendingEvents($cid, $owner['uid']);
1463                 }
1464
1465                 if (empty($contact)) {
1466                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1467                 }
1468                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1469                 Queue::remove($activity);
1470         }
1471
1472         /**
1473          * Transmit pending events to the new follower
1474          *
1475          * @param integer $cid Contact id
1476          * @param integer $uid User id
1477          * @return void
1478          */
1479         private static function transmitPendingEvents(int $cid, int $uid)
1480         {
1481                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1482                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1483
1484                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1485                 while ($event = DBA::fetch($events)) {
1486                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1487                         if (empty($post)) {
1488                                 continue;
1489                         }
1490                         if (DI::config()->get('system', 'bulk_delivery')) {
1491                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1492                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1493                         } else {
1494                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1495                         }
1496                 }
1497         }
1498
1499         /**
1500          * Update the given profile
1501          *
1502          * @param array $activity
1503          * @throws \Exception
1504          */
1505         public static function updatePerson(array $activity)
1506         {
1507                 if (empty($activity['object_id'])) {
1508                         return;
1509                 }
1510
1511                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1512                 Contact::updateFromProbeByURL($activity['object_id']);
1513                 Queue::remove($activity);
1514         }
1515
1516         /**
1517          * Delete the given profile
1518          *
1519          * @param array $activity
1520          * @return void
1521          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1522          */
1523         public static function deletePerson(array $activity)
1524         {
1525                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1526                         Logger::info('Empty object id or actor.');
1527                         return;
1528                 }
1529
1530                 if ($activity['object_id'] != $activity['actor']) {
1531                         Logger::info('Object id does not match actor.');
1532                         return;
1533                 }
1534
1535                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1536                 while ($contact = DBA::fetch($contacts)) {
1537                         Contact::remove($contact['id']);
1538                 }
1539                 DBA::close($contacts);
1540
1541                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1542                 Queue::remove($activity);
1543         }
1544
1545         /**
1546          * Blocks the user by the contact
1547          *
1548          * @param array $activity
1549          * @return void
1550          * @throws \Exception
1551          */
1552         public static function blockAccount(array $activity)
1553         {
1554                 $cid = Contact::getIdForURL($activity['actor']);
1555                 if (empty($cid)) {
1556                         return;
1557                 }
1558
1559                 $uid = User::getIdForURL($activity['object_id']);
1560                 if (empty($uid)) {
1561                         return;
1562                 }
1563
1564                 Contact\User::setIsBlocked($cid, $uid, true);
1565
1566                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1567                 Queue::remove($activity);
1568         }
1569
1570         /**
1571          * Unblocks the user by the contact
1572          *
1573          * @param array $activity
1574          * @return void
1575          * @throws \Exception
1576          */
1577         public static function unblockAccount(array $activity)
1578         {
1579                 $cid = Contact::getIdForURL($activity['actor']);
1580                 if (empty($cid)) {
1581                         return;
1582                 }
1583
1584                 $uid = User::getIdForURL($activity['object_object']);
1585                 if (empty($uid)) {
1586                         return;
1587                 }
1588
1589                 Contact\User::setIsBlocked($cid, $uid, false);
1590
1591                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1592                 Queue::remove($activity);
1593         }
1594
1595         /**
1596          * Accept a follow request
1597          *
1598          * @param array $activity
1599          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1600          * @throws \ImagickException
1601          */
1602         public static function acceptFollowUser(array $activity)
1603         {
1604                 $uid = User::getIdForURL($activity['object_actor']);
1605                 if (empty($uid)) {
1606                         return;
1607                 }
1608
1609                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1610                 if (empty($cid)) {
1611                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1612                         return;
1613                 }
1614
1615                 self::switchContact($cid);
1616
1617                 $fields = ['pending' => false];
1618
1619                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1620                 if ($contact['rel'] == Contact::FOLLOWER) {
1621                         $fields['rel'] = Contact::FRIEND;
1622                 }
1623
1624                 $condition = ['id' => $cid];
1625                 Contact::update($fields, $condition);
1626                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1627                 Queue::remove($activity);
1628         }
1629
1630         /**
1631          * Reject a follow request
1632          *
1633          * @param array $activity
1634          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1635          * @throws \ImagickException
1636          */
1637         public static function rejectFollowUser(array $activity)
1638         {
1639                 $uid = User::getIdForURL($activity['object_actor']);
1640                 if (empty($uid)) {
1641                         return;
1642                 }
1643
1644                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1645                 if (empty($cid)) {
1646                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1647                         return;
1648                 }
1649
1650                 self::switchContact($cid);
1651
1652                 $contact = Contact::getById($cid, ['rel']);
1653                 if ($contact['rel'] == Contact::SHARING) {
1654                         Contact::remove($cid);
1655                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1656                 } elseif ($contact['rel'] == Contact::FRIEND) {
1657                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1658                 } else {
1659                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1660                 }
1661                 Queue::remove($activity);
1662         }
1663
1664         /**
1665          * Undo activity like "like" or "dislike"
1666          *
1667          * @param array $activity
1668          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1669          * @throws \ImagickException
1670          */
1671         public static function undoActivity(array $activity)
1672         {
1673                 if (empty($activity['object_id'])) {
1674                         return;
1675                 }
1676
1677                 if (empty($activity['object_actor'])) {
1678                         return;
1679                 }
1680
1681                 $author_id = Contact::getIdForURL($activity['object_actor']);
1682                 if (empty($author_id)) {
1683                         return;
1684                 }
1685
1686                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1687                 Queue::remove($activity);
1688         }
1689
1690         /**
1691          * Activity to remove a follower
1692          *
1693          * @param array $activity
1694          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1695          * @throws \ImagickException
1696          */
1697         public static function undoFollowUser(array $activity)
1698         {
1699                 $uid = User::getIdForURL($activity['object_object']);
1700                 if (empty($uid)) {
1701                         return;
1702                 }
1703
1704                 $owner = User::getOwnerDataById($uid);
1705                 if (empty($owner)) {
1706                         return;
1707                 }
1708
1709                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1710                 if (empty($cid)) {
1711                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1712                         return;
1713                 }
1714
1715                 self::switchContact($cid);
1716
1717                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1718                 if (!DBA::isResult($contact)) {
1719                         return;
1720                 }
1721
1722                 Contact::removeFollower($contact);
1723                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1724                 Queue::remove($activity);
1725         }
1726
1727         /**
1728          * Switches a contact to AP if needed
1729          *
1730          * @param integer $cid Contact ID
1731          * @return void
1732          * @throws \Exception
1733          */
1734         private static function switchContact(int $cid)
1735         {
1736                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1737                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1738                         return;
1739                 }
1740
1741                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1742                 Contact::updateFromProbe($cid);
1743         }
1744
1745         /**
1746          * Collects implicit mentions like:
1747          * - the author of the parent item
1748          * - all the mentioned conversants in the parent item
1749          *
1750          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1751          * @return array
1752          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1753          */
1754         private static function getImplicitMentionList(array $parent): array
1755         {
1756                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1757
1758                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1759
1760                 $implicit_mentions = [];
1761                 if (empty($parent_author['url'])) {
1762                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1763                 } else {
1764                         $implicit_mentions[] = $parent_author['url'];
1765                         $implicit_mentions[] = $parent_author['nurl'];
1766                         $implicit_mentions[] = $parent_author['alias'];
1767                 }
1768
1769                 if (!empty($parent['alias'])) {
1770                         $implicit_mentions[] = $parent['alias'];
1771                 }
1772
1773                 foreach ($parent_terms as $term) {
1774                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1775                         if (!empty($contact['url'])) {
1776                                 $implicit_mentions[] = $contact['url'];
1777                                 $implicit_mentions[] = $contact['nurl'];
1778                                 $implicit_mentions[] = $contact['alias'];
1779                         }
1780                 }
1781
1782                 return $implicit_mentions;
1783         }
1784
1785         /**
1786          * Strips from the body prepended implicit mentions
1787          *
1788          * @param string $body
1789          * @param array $parent
1790          * @return string
1791          */
1792         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
1793         {
1794                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1795                         return $body;
1796                 }
1797
1798                 $potential_mentions = self::getImplicitMentionList($parent);
1799
1800                 $kept_mentions = [];
1801
1802                 // Extract one prepended mention at a time from the body
1803                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1804                         if (!in_array($matches[2], $potential_mentions)) {
1805                                 $kept_mentions[] = $matches[1];
1806                         }
1807
1808                         $body = $matches[3];
1809                 }
1810
1811                 // Re-appending the kept mentions to the body after extraction
1812                 $kept_mentions[] = $body;
1813
1814                 return implode('', $kept_mentions);
1815         }
1816
1817         /**
1818          * Adds links to string mentions
1819          *
1820          * @param string $body
1821          * @param array  $tags
1822          * @return string
1823          */
1824         protected static function addMentionLinks(string $body, array $tags): string
1825         {
1826                 // This prevents links to be added again to Pleroma-style mention links
1827                 $body = self::normalizeMentionLinks($body);
1828
1829                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1830                         foreach ($tags as $tag) {
1831                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1832                                         continue;
1833                                 }
1834
1835                                 $hash = substr($tag['name'], 0, 1);
1836                                 $name = substr($tag['name'], 1);
1837                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1838                                         $hash = '';
1839                                         $name = $tag['name'];
1840                                 }
1841
1842                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1843                         }
1844
1845                         return $body;
1846                 });
1847
1848                 return $body;
1849         }
1850 }