src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Text\BBCode;
  25 use Friendica\Content\Text\HTML;
  26 use Friendica\Content\Text\Markdown;
  27 use Friendica\Core\Logger;
  28 use Friendica\Core\Protocol;
  29 use Friendica\Core\System;
  30 use Friendica\Core\Worker;
  31 use Friendica\Database\DBA;
  32 use Friendica\DI;
  33 use Friendica\Model\APContact;
  34 use Friendica\Model\Contact;
  35 use Friendica\Model\Conversation;
  36 use Friendica\Model\Event;
  37 use Friendica\Model\GServer;
  38 use Friendica\Model\Item;
  39 use Friendica\Model\ItemURI;
  40 use Friendica\Model\Mail;
  41 use Friendica\Model\Tag;
  42 use Friendica\Model\User;
  43 use Friendica\Model\Post;
  44 use Friendica\Protocol\Activity;
  45 use Friendica\Protocol\ActivityPub;
  46 use Friendica\Protocol\Relay;
  47 use Friendica\Util\DateTimeFormat;
  48 use Friendica\Util\HTTPSignature;
  49 use Friendica\Util\JsonLD;
  50 use Friendica\Util\Network;
  51 use Friendica\Util\Strings;
  52 use Friendica\Worker\Delivery;
  53
  54 /**
  55  * ActivityPub Processor Protocol class
  56  */
  57 class Processor
  58 {
  59         /**
  60          * Extracts the tag character (#, @, !) from mention links
  61          *
  62          * @param string $body
  63          * @return string
  64          */
  65         protected static function normalizeMentionLinks(string $body): string
  66         {
  67                 return preg_replace('%\[url=([^\[\]]*)]([#@!])(.*?)\[/url]%ism', '$2[url=$1]$3[/url]', $body);
  68         }
  69
  70         /**
  71          * Convert the language array into a language JSON
  72          *
  73          * @param array $languages
  74          * @return string language JSON
  75          */
  76         private static function processLanguages(array $languages): string
  77         {
  78                 $codes = array_keys($languages);
  79                 $lang = [];
  80                 foreach ($codes as $code) {
  81                         $lang[$code] = 1;
  82                 }
  83
  84                 if (empty($lang)) {
  85                         return '';
  86                 }
  87
  88                 return json_encode($lang);
  89         }
  90         /**
  91          * Replaces emojis in the body
  92          *
  93          * @param int $uri_id
  94          * @param string $body
  95          * @param array $emojis
  96          *
  97          * @return string with replaced emojis
  98          */
  99         private static function replaceEmojis(int $uri_id, string $body, array $emojis): string
 100         {
 101                 $body = strtr($body,
 102                         array_combine(
 103                                 array_column($emojis, 'name'),
 104                                 array_map(function ($emoji) {
 105                                         return '[emoji=' . $emoji['href'] . ']' . $emoji['name'] . '[/emoji]';
 106                                 }, $emojis)
 107                         )
 108                 );
 109
 110                 // We store the emoji here to be able to avoid storing it in the media
 111                 foreach ($emojis as $emoji) {
 112                         Post\Link::getByLink($uri_id, $emoji['href']);
 113                 }
 114                 return $body;
 115         }
 116
 117         /**
 118          * Store attached media files in the post-media table
 119          *
 120          * @param int $uriid
 121          * @param array $attachment
 122          * @return void
 123          */
 124         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
 125         {
 126                 if (empty($attachment['url'])) {
 127                         return;
 128                 }
 129
 130                 $data = ['uri-id' => $uriid];
 131                 $data['type'] = Post\Media::UNKNOWN;
 132                 $data['url'] = $attachment['url'];
 133                 $data['mimetype'] = $attachment['mediaType'] ?? null;
 134                 $data['height'] = $attachment['height'] ?? null;
 135                 $data['width'] = $attachment['width'] ?? null;
 136                 $data['size'] = $attachment['size'] ?? null;
 137                 $data['preview'] = $attachment['image'] ?? null;
 138                 $data['description'] = $attachment['name'] ?? null;
 139
 140                 Post\Media::insert($data);
 141         }
 142
 143         /**
 144          * Stire attachment data
 145          *
 146          * @param array   $activity
 147          * @param array   $item
 148          */
 149         private static function storeAttachments(array $activity, array $item)
 150         {
 151                 if (empty($activity['attachments'])) {
 152                         return;
 153                 }
 154
 155                 foreach ($activity['attachments'] as $attach) {
 156                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 157                 }
 158         }
 159
 160         /**
 161          * Store attachment data
 162          *
 163          * @param array   $activity
 164          * @param array   $item
 165          */
 166         private static function storeQuestion(array $activity, array $item)
 167         {
 168                 if (empty($activity['question'])) {
 169                         return;
 170                 }
 171                 $question = ['multiple' => $activity['question']['multiple']];
 172
 173                 if (!empty($activity['question']['voters'])) {
 174                         $question['voters'] = $activity['question']['voters'];
 175                 }
 176
 177                 if (!empty($activity['question']['end-time'])) {
 178                         $question['end-time'] = DateTimeFormat::utc($activity['question']['end-time']);
 179                 }
 180
 181                 Post\Question::update($item['uri-id'], $question);
 182
 183                 foreach ($activity['question']['options'] as $key => $option) {
 184                         $option = ['name' => $option['name'], 'replies' => $option['replies']];
 185                         Post\QuestionOption::update($item['uri-id'], $key, $option);
 186                 }
 187
 188                 Logger::debug('Storing incoming question', ['type' => $activity['type'], 'uri-id' => $item['uri-id'], 'question' => $activity['question']]);
 189         }
 190
 191         /**
 192          * Updates a message
 193          *
 194          * @param array      $activity   Activity array
 195          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 196          * @throws \ImagickException
 197          */
 198         public static function updateItem(array $activity)
 199         {
 200                 $item = Post::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity', 'post-type'], ['uri' => $activity['id']]);
 201                 if (!DBA::isResult($item)) {
 202                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 203                         $item = self::createItem($activity);
 204                         if (empty($item)) {
 205                                 return;
 206                         }
 207
 208                         self::postItem($activity, $item);
 209                         return;
 210                 }
 211
 212                 $item['changed'] = DateTimeFormat::utcNow();
 213                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 214
 215                 $item = self::processContent($activity, $item);
 216
 217                 self::storeAttachments($activity, $item);
 218                 self::storeQuestion($activity, $item);
 219
 220                 if (empty($item)) {
 221                         return;
 222                 }
 223
 224                 Post\History::add($item['uri-id'], $item);
 225                 Item::update($item, ['uri' => $activity['id']]);
 226
 227                 Queue::remove($activity);
 228
 229                 if ($activity['object_type'] == 'as:Event') {
 230                         $posts = Post::select(['event-id', 'uid'], ["`uri` = ? AND `event-id` > ?", $activity['id'], 0]);
 231                         while ($post = DBA::fetch($posts)) {
 232                                 self::updateEvent($post['event-id'], $activity);
 233                         }
 234                 }
 235         }
 236
 237         /**
 238          * Update an existing event
 239          *
 240          * @param int $event_id
 241          * @param array $activity
 242          */
 243         private static function updateEvent(int $event_id, array $activity)
 244         {
 245                 $event = DBA::selectFirst('event', [], ['id' => $event_id]);
 246
 247                 $event['edited']   = DateTimeFormat::utc($activity['updated']);
 248                 $event['summary']  = HTML::toBBCode($activity['name']);
 249                 $event['desc']     = HTML::toBBCode($activity['content']);
 250                 if (!empty($activity['start-time'])) {
 251                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 252                 }
 253                 if (!empty($activity['end-time'])) {
 254                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 255                 }
 256                 $event['nofinish'] = empty($event['finish']);
 257                 $event['location'] = $activity['location'];
 258
 259                 Logger::info('Updating event', ['uri' => $activity['id'], 'id' => $event_id]);
 260                 Event::store($event);
 261         }
 262
 263         /**
 264          * Prepares data for a message
 265          *
 266          * @param array      $activity   Activity array
 267          * @return array Internal item
 268          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 269          * @throws \ImagickException
 270          */
 271         public static function createItem(array $activity): array
 272         {
 273                 $item = [];
 274                 $item['verb'] = Activity::POST;
 275                 $item['thr-parent'] = $activity['reply-to-id'];
 276
 277                 if ($activity['reply-to-id'] == $activity['id']) {
 278                         $item['gravity'] = GRAVITY_PARENT;
 279                         $item['object-type'] = Activity\ObjectType::NOTE;
 280                 } else {
 281                         $item['gravity'] = GRAVITY_COMMENT;
 282                         $item['object-type'] = Activity\ObjectType::COMMENT;
 283                 }
 284
 285                 if (!empty($activity['context'])) {
 286                         $item['conversation'] = $activity['context'];
 287                 } elseif (!empty($activity['conversation'])) {
 288                         $item['conversation'] = $activity['conversation'];
 289                 }
 290
 291                 if (!empty($item['conversation'])) {
 292                         $conversation = Post::selectFirstThread(['uri'], ['conversation' => $item['conversation']]);
 293                         if (!empty($conversation)) {
 294                                 Logger::debug('Got conversation', ['conversation' => $item['conversation'], 'parent' => $conversation]);
 295                                 $item['parent-uri'] = $conversation['uri'];
 296                         }
 297                 } else {
 298                         $conversation = [];
 299                 }
 300
 301                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Post::exists(['uri' => $activity['reply-to-id']])) {
 302                         $recursion_depth = $activity['recursion-depth'] ?? 0;
 303                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 304                         if ($recursion_depth < 10) {
 305                                 $result = self::fetchMissingActivity($activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 306                                 if (empty($result) && self::isActivityGone($activity['reply-to-id'])) {
 307                                         // Recursively delete this and all depending entries
 308                                         Queue::deleteById($activity['entry-id']);
 309                                         return [];
 310                                 }
 311                                 $fetch_by_worker = empty($result);
 312                         } else {
 313                                 Logger::notice('Recursion level is too high.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 314                                 $fetch_by_worker = true;
 315                         }
 316
 317                         if ($fetch_by_worker && Queue::hasWorker($activity)) {
 318                                 Logger::notice('There is already a worker task to fetch the post.', ['id' => $activity['id'], 'parent' => $activity['reply-to-id']]);
 319                                 $fetch_by_worker = false;
 320                                 if (!empty($conversation)) {
 321                                         return [];
 322                                 }
 323                         }
 324
 325                         if ($fetch_by_worker) {
 326                                 Logger::notice('Fetching is done by worker.', ['parent' => $activity['reply-to-id'], 'recursion-depth' => $recursion_depth]);
 327                                 $activity['recursion-depth'] = 0;
 328                                 $wid = Worker::add(PRIORITY_HIGH, 'FetchMissingActivity', $activity['reply-to-id'], $activity, '', Receiver::COMPLETION_AUTO);
 329                                 Queue::setWorkerId($activity, $wid);
 330                                 if (!empty($conversation)) {
 331                                         return [];
 332                                 }
 333                         } elseif (!empty($result)) {
 334                                 if (($item['thr-parent'] != $result) && Post::exists(['uri' => $result])) {
 335                                         $item['thr-parent'] = $result;
 336                                 }
 337                         }
 338                 }
 339
 340                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 341
 342                 if (empty($conversation) && empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Post::exists(['uri' => $item['thr-parent']])) {
 343                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 344                         return [];
 345                 }
 346
 347                 $item['network'] = Protocol::ACTIVITYPUB;
 348                 $item['author-link'] = $activity['author'];
 349                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 350                 $item['owner-link'] = $activity['actor'];
 351                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 352
 353                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 354                         $item['private'] = Item::UNLISTED;
 355                 } elseif (in_array(0, $activity['receiver'])) {
 356                         $item['private'] = Item::PUBLIC;
 357                 } else {
 358                         $item['private'] = Item::PRIVATE;
 359                 }
 360
 361                 if (!empty($activity['raw'])) {
 362                         $item['source'] = $activity['raw'];
 363                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 364
 365                         if (isset($activity['push'])) {
 366                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 367                         }
 368                 }
 369
 370                 if (!empty($activity['from-relay'])) {
 371                         $item['direction'] = Conversation::RELAY;
 372                 }
 373
 374                 if ($activity['object_type'] == 'as:Article') {
 375                         $item['post-type'] = Item::PT_ARTICLE;
 376                 } elseif ($activity['object_type'] == 'as:Audio') {
 377                         $item['post-type'] = Item::PT_AUDIO;
 378                 } elseif ($activity['object_type'] == 'as:Document') {
 379                         $item['post-type'] = Item::PT_DOCUMENT;
 380                 } elseif ($activity['object_type'] == 'as:Event') {
 381                         $item['post-type'] = Item::PT_EVENT;
 382                 } elseif ($activity['object_type'] == 'as:Image') {
 383                         $item['post-type'] = Item::PT_IMAGE;
 384                 } elseif ($activity['object_type'] == 'as:Page') {
 385                         $item['post-type'] = Item::PT_PAGE;
 386                 } elseif ($activity['object_type'] == 'as:Question') {
 387                         $item['post-type'] = Item::PT_POLL;
 388                 } elseif ($activity['object_type'] == 'as:Video') {
 389                         $item['post-type'] = Item::PT_VIDEO;
 390                 } else {
 391                         $item['post-type'] = Item::PT_NOTE;
 392                 }
 393
 394                 $item['isForum'] = false;
 395
 396                 if (!empty($activity['thread-completion'])) {
 397                         if ($activity['thread-completion'] != $item['owner-id']) {
 398                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 399                                 $item['causer-link'] = $actor['url'];
 400                                 $item['causer-id'] = $activity['thread-completion'];
 401                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 402                         } else {
 403                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 404                                 $item['causer-link'] = $item['owner-link'];
 405                                 $item['causer-id']   = $item['owner-id'];
 406                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 407                         }
 408
 409                         $item['owner-link'] = $item['author-link'];
 410                         $item['owner-id'] = $item['author-id'];
 411                 } else {
 412                         $actor = APContact::getByURL($item['owner-link'], false);
 413                         $item['isForum'] = ($actor['type'] == 'Group');
 414                 }
 415
 416                 $item['uri'] = $activity['id'];
 417
 418                 if (empty($activity['published']) || empty($activity['updated'])) {
 419                         DI::logger()->notice('published or updated keys are empty for activity', ['activity' => $activity, 'callstack' => System::callstack(10)]);
 420                 }
 421
 422                 $item['created'] = DateTimeFormat::utc($activity['published'] ?? 'now');
 423                 $item['edited'] = DateTimeFormat::utc($activity['updated'] ?? 'now');
 424                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 425                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 426
 427                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 428                 if (empty($item['uri-id'])) {
 429                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 430                         return [];
 431                 }
 432
 433                 $item = self::processContent($activity, $item);
 434                 if (empty($item)) {
 435                         Logger::info('Message was not processed');
 436                         return [];
 437                 }
 438
 439                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 440
 441                 self::storeAttachments($activity, $item);
 442                 self::storeQuestion($activity, $item);
 443
 444                 // We received the post via AP, so we set the protocol of the server to AP
 445                 $contact = Contact::getById($item['author-id'], ['gsid']);
 446                 if (!empty($contact['gsid'])) {
 447                         GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 448                 }
 449
 450                 if ($item['author-id'] != $item['owner-id']) {
 451                         $contact = Contact::getById($item['owner-id'], ['gsid']);
 452                         if (!empty($contact['gsid'])) {
 453                                 GServer::setProtocol($contact['gsid'], Post\DeliveryData::ACTIVITYPUB);
 454                         }
 455                 }
 456
 457                 return $item;
 458         }
 459
 460         /**
 461          * Check if a given activity is no longer available
 462          *
 463          * @param string $url
 464          *
 465          * @return boolean
 466          */
 467         public static function isActivityGone(string $url): bool
 468         {
 469                 $curlResult = HTTPSignature::fetchRaw($url, 0);
 470
 471                 if (Network::isUrlBlocked($url)) {
 472                         return true;
 473                 }
 474
 475                 // @todo To ensure that the remote system is working correctly, we can check if the "Content-Type" contains JSON
 476                 if (in_array($curlResult->getReturnCode(), [404])) {
 477                         return true;
 478                 }
 479
 480                 $object = json_decode($curlResult->getBody(), true);
 481                 if (!empty($object)) {
 482                         $activity = JsonLD::compact($object);
 483                         if (JsonLD::fetchElement($activity, '@type') == 'as:Tombstone') {
 484                                 return true;
 485                         }
 486                 }
 487
 488                 return false;
 489         }
 490         /**
 491          * Delete items
 492          *
 493          * @param array $activity
 494          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 495          * @throws \ImagickException
 496          */
 497         public static function deleteItem(array $activity)
 498         {
 499                 $owner = Contact::getIdForURL($activity['actor']);
 500
 501                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 502                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 503                 Queue::remove($activity);
 504         }
 505
 506         /**
 507          * Prepare the item array for an activity
 508          *
 509          * @param array $activity Activity array
 510          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 511          * @throws \ImagickException
 512          */
 513         public static function addTag(array $activity)
 514         {
 515                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 516                         return;
 517                 }
 518
 519                 foreach ($activity['receiver'] as $receiver) {
 520                         $item = Post::selectFirst(['id', 'uri-id', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 521                         if (!DBA::isResult($item)) {
 522                                 // We don't fetch missing content for this purpose
 523                                 continue;
 524                         }
 525
 526                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 527                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 528                                 continue;
 529                         }
 530
 531                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 532                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 533                 }
 534         }
 535
 536         /**
 537          * Prepare the item array for an activity
 538          *
 539          * @param array      $activity   Activity array
 540          * @param string     $verb       Activity verb
 541          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 542          * @throws \ImagickException
 543          */
 544         public static function createActivity(array $activity, string $verb)
 545         {
 546                 $activity['reply-to-id'] = $activity['object_id'];
 547                 $item = self::createItem($activity);
 548                 if (empty($item)) {
 549                         return;
 550                 }
 551
 552                 $item['verb'] = $verb;
 553                 $item['thr-parent'] = $activity['object_id'];
 554                 $item['gravity'] = GRAVITY_ACTIVITY;
 555                 unset($item['post-type']);
 556                 $item['object-type'] = Activity\ObjectType::NOTE;
 557
 558                 if (!empty($activity['content'])) {
 559                         $item['body'] = HTML::toBBCode($activity['content']);
 560                 }
 561
 562                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 563
 564                 self::postItem($activity, $item);
 565         }
 566
 567         /**
 568          * Fetch the Uri-Id of a post for the "featured" collection
 569          *
 570          * @param array $activity
 571          * @return null|int
 572          */
 573         private static function getUriIdForFeaturedCollection(array $activity)
 574         {
 575                 $actor = APContact::getByURL($activity['actor']);
 576                 if (empty($actor)) {
 577                         return null;
 578                 }
 579
 580                 // Refetch the account when the "featured" collection is missing.
 581                 // This can be removed in a future version (end of 2022 should be good).
 582                 if (empty($actor['featured'])) {
 583                         $actor = APContact::getByURL($activity['actor'], true);
 584                         if (empty($actor)) {
 585                                 return null;
 586                         }
 587                 }
 588
 589                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 590                 if (empty($parent['uri-id'])) {
 591                         if (self::fetchMissingActivity($activity['object_id'], $activity, '', Receiver::COMPLETION_AUTO)) {
 592                                 $parent = Post::selectFirst(['uri-id'], ['uri' => $activity['object_id']]);
 593                         }
 594                 }
 595
 596                 if (!empty($parent['uri-id'])) {
 597                         return $parent['uri-id'];
 598                 }
 599
 600                 return null;
 601         }
 602
 603         /**
 604          * Add a post to the "Featured" collection
 605          *
 606          * @param array $activity
 607          */
 608         public static function addToFeaturedCollection(array $activity)
 609         {
 610                 $uriid = self::getUriIdForFeaturedCollection($activity);
 611                 if (empty($uriid)) {
 612                         return;
 613                 }
 614
 615                 Logger::debug('Add post to featured collection', ['uri-id' => $uriid]);
 616
 617                 Post\Collection::add($uriid, Post\Collection::FEATURED);
 618                 Queue::remove($activity);
 619         }
 620
 621         /**
 622          * Remove a post to the "Featured" collection
 623          *
 624          * @param array $activity
 625          */
 626         public static function removeFromFeaturedCollection(array $activity)
 627         {
 628                 $uriid = self::getUriIdForFeaturedCollection($activity);
 629                 if (empty($uriid)) {
 630                         return;
 631                 }
 632
 633                 Logger::debug('Remove post from featured collection', ['uri-id' => $uriid]);
 634
 635                 Post\Collection::remove($uriid, Post\Collection::FEATURED);
 636                 Queue::remove($activity);
 637         }
 638
 639         /**
 640          * Create an event
 641          *
 642          * @param array $activity Activity array
 643          * @param array $item
 644          *
 645          * @return int event id
 646          * @throws \Exception
 647          */
 648         public static function createEvent(array $activity, array $item): int
 649         {
 650                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 651                 $event['desc']      = HTML::toBBCode($activity['content']);
 652                 if (!empty($activity['start-time'])) {
 653                         $event['start']  = DateTimeFormat::utc($activity['start-time']);
 654                 }
 655                 if (!empty($activity['end-time'])) {
 656                         $event['finish'] = DateTimeFormat::utc($activity['end-time']);
 657                 }
 658                 $event['nofinish']  = empty($event['finish']);
 659                 $event['location']  = $activity['location'];
 660                 $event['cid']       = $item['contact-id'];
 661                 $event['uid']       = $item['uid'];
 662                 $event['uri']       = $item['uri'];
 663                 $event['edited']    = $item['edited'];
 664                 $event['private']   = $item['private'];
 665                 $event['guid']      = $item['guid'];
 666                 $event['plink']     = $item['plink'];
 667                 $event['network']   = $item['network'];
 668                 $event['protocol']  = $item['protocol'];
 669                 $event['direction'] = $item['direction'];
 670                 $event['source']    = $item['source'];
 671
 672                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 673                 if (DBA::isResult($ev)) {
 674                         $event['id'] = $ev['id'];
 675                 }
 676
 677                 $event_id = Event::store($event);
 678
 679                 Logger::info('Event was stored', ['id' => $event_id]);
 680
 681                 return $event_id;
 682         }
 683
 684         /**
 685          * Process the content
 686          *
 687          * @param array $activity Activity array
 688          * @param array $item
 689          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 690          * @throws \Exception
 691          */
 692         private static function processContent(array $activity, array $item)
 693         {
 694                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 695                         $item['title'] = strip_tags($activity['name']);
 696                         $content = Markdown::toBBCode($activity['content']);
 697                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 698                         $item['title'] = $activity['name'];
 699                         $content = $activity['content'];
 700                 } else {
 701                         // By default assume "text/html"
 702                         $item['title'] = HTML::toBBCode($activity['name'] ?? '');
 703                         $content = HTML::toBBCode($activity['content'] ?? '');
 704                 }
 705
 706                 $item['title'] = trim(BBCode::toPlaintext($item['title']));
 707
 708                 if (!empty($activity['languages'])) {
 709                         $item['language'] = self::processLanguages($activity['languages']);
 710                 }
 711
 712                 if (!empty($activity['emojis'])) {
 713                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 714                 }
 715
 716                 $content = self::addMentionLinks($content, $activity['tags']);
 717
 718                 if (!empty($activity['source'])) {
 719                         $item['body'] = $activity['source'];
 720                         $item['raw-body'] = $content;
 721                         $item['body'] = Item::improveSharedDataInBody($item);
 722                 } else {
 723                         $parent_uri = $item['parent-uri'] ?? $item['thr-parent'];
 724                         if (empty($activity['directmessage']) && ($parent_uri != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 725                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $parent_uri]);
 726                                 if (!DBA::isResult($parent)) {
 727                                         Logger::warning('Unknown parent item.', ['uri' => $parent_uri]);
 728                                         return false;
 729                                 }
 730                                 if (($item['private'] == Item::PRIVATE) && ($parent['private'] != Item::PRIVATE)) {
 731                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 732                                         return false;
 733                                 }
 734
 735                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 736                         }
 737                         $item['content-warning'] = HTML::toBBCode($activity['summary'] ?? '');
 738                         $item['raw-body'] = $item['body'] = $content;
 739                 }
 740
 741                 self::storeFromBody($item);
 742                 self::storeTags($item['uri-id'], $activity['tags']);
 743
 744                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 745
 746                 $item['location'] = $activity['location'];
 747
 748                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 749                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 750                 }
 751
 752                 $item['app'] = $activity['generator'];
 753
 754                 return $item;
 755         }
 756
 757         /**
 758          * Store hashtags and mentions
 759          *
 760          * @param array $item
 761          */
 762         private static function storeFromBody(array $item)
 763         {
 764                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 765                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 766
 767                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 768         }
 769
 770         /**
 771          * Generate a GUID out of an URL of an ActivityPub post.
 772          *
 773          * @param string $url message URL
 774          * @return string with GUID
 775          */
 776         private static function getGUIDByURL(string $url): string
 777         {
 778                 $parsed = parse_url($url);
 779
 780                 $host_hash = hash('crc32', $parsed['host']);
 781
 782                 unset($parsed["scheme"]);
 783                 unset($parsed["host"]);
 784
 785                 $path = implode("/", $parsed);
 786
 787                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 788         }
 789
 790         /**
 791          * Checks if an incoming message is wanted
 792          *
 793          * @param array $activity
 794          * @param array $item
 795          * @return boolean Is the message wanted?
 796          */
 797         private static function isSolicitedMessage(array $activity, array $item): bool
 798         {
 799                 // The checks are split to improve the support when searching why a message was accepted.
 800                 if (count($activity['receiver']) != 1) {
 801                         // The message has more than one receiver, so it is wanted.
 802                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 803                         return true;
 804                 }
 805
 806                 if ($item['private'] == Item::PRIVATE) {
 807                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 808                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 809                         return true;
 810                 }
 811
 812                 if (!empty($activity['from-relay'])) {
 813                         // We check relay posts at another place. When it arrived here, the message is already checked.
 814                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 815                         return true;
 816                 }
 817
 818                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 819                         // Manual completions and completions caused by reshares are allowed without any further checks.
 820                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 821                         return true;
 822                 }
 823
 824                 if ($item['gravity'] != GRAVITY_PARENT) {
 825                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 826                         // This can possibly be improved in the future.
 827                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 828                         return true;
 829                 }
 830
 831                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 832                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 833                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 834                         return true;
 835                 } else {
 836                         return false;
 837                 }
 838         }
 839
 840         /**
 841          * Creates an item post
 842          *
 843          * @param array $activity Activity data
 844          * @param array $item     item array
 845          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 846          * @throws \ImagickException
 847          */
 848         public static function postItem(array $activity, array $item)
 849         {
 850                 if (empty($item)) {
 851                         return;
 852                 }
 853
 854                 $stored = false;
 855                 $success = false;
 856                 ksort($activity['receiver']);
 857
 858                 if (!self::isSolicitedMessage($activity, $item)) {
 859                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 860                         return;
 861                 }
 862
 863                 foreach ($activity['receiver'] as $receiver) {
 864                         if ($receiver == -1) {
 865                                 continue;
 866                         }
 867
 868                         $item['uid'] = $receiver;
 869
 870                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 871                         switch($type) {
 872                                 case Receiver::TARGET_TO:
 873                                         $item['post-reason'] = Item::PR_TO;
 874                                         break;
 875                                 case Receiver::TARGET_CC:
 876                                         $item['post-reason'] = Item::PR_CC;
 877                                         break;
 878                                 case Receiver::TARGET_BTO:
 879                                         $item['post-reason'] = Item::PR_BTO;
 880                                         break;
 881                                 case Receiver::TARGET_BCC:
 882                                         $item['post-reason'] = Item::PR_BCC;
 883                                         break;
 884                                 case Receiver::TARGET_FOLLOWER:
 885                                         $item['post-reason'] = Item::PR_FOLLOWER;
 886                                         break;
 887                                 case Receiver::TARGET_ANSWER:
 888                                         $item['post-reason'] = Item::PR_COMMENT;
 889                                         break;
 890                                 case Receiver::TARGET_GLOBAL:
 891                                         $item['post-reason'] = Item::PR_GLOBAL;
 892                                         break;
 893                                 default:
 894                                         $item['post-reason'] = Item::PR_NONE;
 895                         }
 896
 897                         if (!empty($activity['from-relay'])) {
 898                                 $item['post-reason'] = Item::PR_RELAY;
 899                         } elseif (!empty($activity['thread-completion'])) {
 900                                 $item['post-reason'] = Item::PR_FETCHED;
 901                         }
 902
 903                         if ($item['isForum'] ?? false) {
 904                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 905                         } else {
 906                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 907                         }
 908
 909                         if (($receiver != 0) && empty($item['contact-id'])) {
 910                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 911                         }
 912
 913                         if (!empty($activity['directmessage'])) {
 914                                 self::postMail($activity, $item);
 915                                 continue;
 916                         }
 917
 918                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 919                                 if ($item['post-reason'] == Item::PR_BCC) {
 920                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 921                                         continue;
 922                                 }
 923
 924                                 if (
 925                                         !empty($activity['thread-children-type'])
 926                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 927                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 928                                 ) {
 929                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 930                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 931                                         continue;
 932                                 }
 933                         }
 934
 935                         $is_forum = false;
 936
 937                         if ($receiver != 0) {
 938                                 $user = User::getById($receiver, ['account-type']);
 939                                 if (!empty($user['account-type'])) {
 940                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 941                                 }
 942                         }
 943
 944                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 945                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 946
 947                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 948                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 949                                 }
 950
 951                                 if ($skip) {
 952                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 953                                         continue;
 954                                 }
 955
 956                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 957                         }
 958
 959                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 960                                 $event_id = self::createEvent($activity, $item);
 961
 962                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 963                         }
 964
 965                         $item_id = Item::insert($item);
 966                         if ($item_id) {
 967                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 968                                 $success = true;
 969                         } else {
 970                                 Logger::notice('Item insertion aborted', ['uri' => $item['uri'], 'uid' => $item['uid']]);
 971                                 if (Item::isTooOld($item) || !Item::isValid($item)) {
 972                                         Queue::remove($activity);
 973                                 }
 974                         }
 975
 976                         if ($item['uid'] == 0) {
 977                                 $stored = $item_id;
 978                         }
 979                 }
 980
 981                 if ($success) {
 982                         Queue::remove($activity);
 983
 984                         if (Queue::hasChildren($item['uri'])) {
 985                                 Worker::add(PRIORITY_HIGH, 'ProcessReplyByUri', $item['uri']);
 986                         }
 987                 }
 988
 989                 // Store send a follow request for every reshare - but only when the item had been stored
 990                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && !empty($item['author-link']) && ($item['author-link'] != $item['owner-link'])) {
 991                         $author = APContact::getByURL($item['owner-link'], false);
 992                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 993                         if ($author['type'] != 'Group') {
 994                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 995                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 996                         }
 997                 }
 998         }
 999
1000         /**
1001          * Store tags and mentions into the tag table
1002          *
1003          * @param integer $uriid
1004          * @param array $tags
1005          */
1006         private static function storeTags(int $uriid, array $tags = null)
1007         {
1008                 foreach ($tags as $tag) {
1009                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1010                                 continue;
1011                         }
1012
1013                         $hash = substr($tag['name'], 0, 1);
1014
1015                         if ($tag['type'] == 'Mention') {
1016                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
1017                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
1018                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
1019                                         $tag['name'] = substr($tag['name'], 1);
1020                                 }
1021                                 $type = Tag::IMPLICIT_MENTION;
1022
1023                                 if (!empty($tag['href'])) {
1024                                         $apcontact = APContact::getByURL($tag['href']);
1025                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
1026                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
1027                                         }
1028                                 }
1029                         } elseif ($tag['type'] == 'Hashtag') {
1030                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
1031                                         $tag['name'] = substr($tag['name'], 1);
1032                                 }
1033                                 $type = Tag::HASHTAG;
1034                         }
1035
1036                         if (empty($tag['name'])) {
1037                                 continue;
1038                         }
1039
1040                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
1041                 }
1042         }
1043
1044         public static function storeReceivers(int $uriid, array $receivers)
1045         {
1046                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
1047                         if (!empty($receivers[$element])) {
1048                                 foreach ($receivers[$element] as $receiver) {
1049                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
1050                                                 $name = Receiver::PUBLIC_COLLECTION;
1051                                         } else {
1052                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
1053                                         }
1054
1055                                         $target = Tag::getTargetType($receiver);
1056                                         Logger::debug('Got target type', ['type' => $target, 'url' => $receiver]);
1057                                         Tag::store($uriid, $type, $name, $receiver, $target);
1058                                 }
1059                         }
1060                 }
1061         }
1062
1063         /**
1064          * Creates an mail post
1065          *
1066          * @param array $activity Activity data
1067          * @param array $item     item array
1068          * @return int|bool New mail table row id or false on error
1069          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1070          */
1071         private static function postMail(array $activity, array $item)
1072         {
1073                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
1074                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
1075                         return false;
1076                 }
1077
1078                 Logger::info('Direct Message', $item);
1079
1080                 $msg = [];
1081                 $msg['uid'] = $item['uid'];
1082
1083                 $msg['contact-id'] = $item['contact-id'];
1084
1085                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
1086                 $msg['from-name'] = $contact['name'];
1087                 $msg['from-url'] = $contact['url'];
1088                 $msg['from-photo'] = $contact['photo'];
1089
1090                 $msg['uri'] = $item['uri'];
1091                 $msg['created'] = $item['created'];
1092
1093                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
1094                 if (DBA::isResult($parent)) {
1095                         $msg['parent-uri'] = $parent['parent-uri'];
1096                         $msg['title'] = $parent['title'];
1097                 } else {
1098                         $msg['parent-uri'] = $item['thr-parent'];
1099
1100                         if (!empty($item['title'])) {
1101                                 $msg['title'] = $item['title'];
1102                         } elseif (!empty($item['content-warning'])) {
1103                                 $msg['title'] = $item['content-warning'];
1104                         } else {
1105                                 // Trying to generate a title out of the body
1106                                 $title = $item['body'];
1107
1108                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
1109                                         $title = $matches[3];
1110                                 }
1111
1112                                 $title = trim(BBCode::toPlaintext($title));
1113
1114                                 if (strlen($title) > 20) {
1115                                         $title = substr($title, 0, 20) . '...';
1116                                 }
1117
1118                                 $msg['title'] = $title;
1119                         }
1120                 }
1121                 $msg['body'] = $item['body'];
1122
1123                 return Mail::insert($msg);
1124         }
1125
1126         /**
1127          * Fetch featured posts from a contact with the given url
1128          *
1129          * @param string $url
1130          * @return void
1131          */
1132         public static function fetchFeaturedPosts(string $url)
1133         {
1134                 Logger::info('Fetch featured posts', ['contact' => $url]);
1135
1136                 $apcontact = APContact::getByURL($url);
1137                 if (empty($apcontact['featured'])) {
1138                         Logger::info('Contact does not have a featured collection', ['contact' => $url]);
1139                         return;
1140                 }
1141
1142                 $pcid = Contact::getIdForURL($url, 0, false);
1143                 if (empty($pcid)) {
1144                         Logger::info('Contact not found', ['contact' => $url]);
1145                         return;
1146                 }
1147
1148                 $posts = Post\Collection::selectToArrayForContact($pcid, Post\Collection::FEATURED);
1149                 if (!empty($posts)) {
1150                         $old_featured = array_column($posts, 'uri-id');
1151                 } else {
1152                         $old_featured = [];
1153                 }
1154
1155                 $featured = ActivityPub::fetchItems($apcontact['featured']);
1156                 if (empty($featured)) {
1157                         Logger::info('Contact does not have featured posts', ['contact' => $url]);
1158
1159                         foreach ($old_featured as $uri_id) {
1160                                 Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1161                                 Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1162                         }
1163                         return;
1164                 }
1165
1166                 $new = 0;
1167                 $old = 0;
1168
1169                 foreach ($featured as $post) {
1170                         if (empty($post['id'])) {
1171                                 continue;
1172                         }
1173                         $id = Item::fetchByLink($post['id']);
1174                         if (!empty($id)) {
1175                                 $item = Post::selectFirst(['uri-id', 'featured'], ['id' => $id]);
1176                                 if (!empty($item['uri-id'])) {
1177                                         if (!$item['featured']) {
1178                                                 Post\Collection::add($item['uri-id'], Post\Collection::FEATURED);
1179                                                 Logger::debug('Added featured post', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1180                                                 $new++;
1181                                         } else {
1182                                                 Logger::debug('Post already had been featured', ['uri-id' => $item['uri-id'], 'contact' => $url]);
1183                                                 $old++;
1184                                         }
1185
1186                                         $index = array_search($item['uri-id'], $old_featured);
1187                                         if (!($index === false)) {
1188                                                 unset($old_featured[$index]);
1189                                         }
1190                                 }
1191                         }
1192                 }
1193
1194                 foreach ($old_featured as $uri_id) {
1195                         Post\Collection::remove($uri_id, Post\Collection::FEATURED);
1196                         Logger::debug('Removed no longer featured post', ['uri-id' => $uri_id, 'contact' => $url]);
1197                 }
1198
1199                 Logger::info('Fetched featured posts', ['new' => $new, 'old' => $old, 'contact' => $url]);
1200         }
1201
1202         /**
1203          * Fetches missing posts
1204          *
1205          * @param string     $url         message URL
1206          * @param array      $child       activity array with the child of this message
1207          * @param string     $relay_actor Relay actor
1208          * @param int        $completion  Completion mode, see Receiver::COMPLETION_*
1209          * @return string fetched message URL
1210          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1211          * @throws \ImagickException
1212          */
1213         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL): string
1214         {
1215                 if (!empty($child['receiver'])) {
1216                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
1217                 } else {
1218                         $uid = 0;
1219                 }
1220
1221                 $object = ActivityPub::fetchContent($url, $uid);
1222                 if (empty($object)) {
1223                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
1224                         return '';
1225                 }
1226
1227                 if (empty($object['id'])) {
1228                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
1229                         return '';
1230                 }
1231
1232                 $signer = [];
1233
1234                 if (!empty($object['attributedTo'])) {
1235                         $attributed_to = $object['attributedTo'];
1236                         if (is_array($attributed_to)) {
1237                                 $compacted = JsonLD::compact($object);
1238                                 $attributed_to = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
1239                         }
1240                         $signer[] = $attributed_to;
1241                 }
1242
1243                 if (!empty($object['actor'])) {
1244                         $object_actor = $object['actor'];
1245                 } elseif (!empty($attributed_to)) {
1246                         $object_actor = $attributed_to;
1247                 } else {
1248                         // Shouldn't happen
1249                         $object_actor = '';
1250                 }
1251
1252                 $signer[] = $object_actor;
1253
1254                 if (!empty($child['author'])) {
1255                         $actor = $child['author'];
1256                         $signer[] = $actor;
1257                 } else {
1258                         $actor = $object_actor;
1259                 }
1260
1261                 if (!empty($object['published'])) {
1262                         $published = $object['published'];
1263                 } elseif (!empty($child['published'])) {
1264                         $published = $child['published'];
1265                 } else {
1266                         $published = DateTimeFormat::utcNow();
1267                 }
1268
1269                 $activity = [];
1270                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
1271                 unset($object['@context']);
1272                 $activity['id'] = $object['id'];
1273                 $activity['to'] = $object['to'] ?? [];
1274                 $activity['cc'] = $object['cc'] ?? [];
1275                 $activity['actor'] = $actor;
1276                 $activity['object'] = $object;
1277                 $activity['published'] = $published;
1278                 $activity['type'] = 'Create';
1279
1280                 $ldactivity = JsonLD::compact($activity);
1281
1282                 $ldactivity['recursion-depth'] = !empty($child['recursion-depth']) ? $child['recursion-depth'] + 1 : 1;
1283
1284                 if (!empty($relay_actor)) {
1285                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
1286                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
1287                 } elseif (!empty($child['thread-completion'])) {
1288                         $ldactivity['thread-completion'] = $child['thread-completion'];
1289                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
1290                 } else {
1291                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
1292                         $ldactivity['completion-mode']   = $completion;
1293                 }
1294
1295                 if (!empty($child['type'])) {
1296                         $ldactivity['thread-children-type'] = $child['type'];
1297                 }
1298
1299                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
1300                         return '';
1301                 }
1302
1303                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
1304
1305                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1306
1307                 return $activity['id'];
1308         }
1309
1310         /**
1311          * Test if incoming relay messages should be accepted
1312          *
1313          * @param array $activity activity array
1314          * @param string $id      object ID
1315          * @return boolean true if message is accepted
1316          */
1317         private static function acceptIncomingMessage(array $activity, string $id): bool
1318         {
1319                 if (empty($activity['as:object'])) {
1320                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1321                         return true;
1322                 }
1323
1324                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1325                 $uriid = ItemURI::getIdByURI($replyto ?? '');
1326                 if (Post::exists(['uri-id' => $uriid])) {
1327                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1328                         return true;
1329                 }
1330
1331                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1332                 $authorid = Contact::getIdForURL($attributed_to);
1333
1334                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value') ?? '');
1335
1336                 $messageTags = [];
1337                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1338                 if (!empty($tags)) {
1339                         foreach ($tags as $tag) {
1340                                 if ($tag['type'] != 'Hashtag') {
1341                                         continue;
1342                                 }
1343                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1344                         }
1345                 }
1346
1347                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1348         }
1349
1350         /**
1351          * perform a "follow" request
1352          *
1353          * @param array $activity
1354          * @return void
1355          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1356          * @throws \ImagickException
1357          */
1358         public static function followUser(array $activity)
1359         {
1360                 $uid = User::getIdForURL($activity['object_id']);
1361                 if (empty($uid)) {
1362                         Queue::remove($activity);
1363                         return;
1364                 }
1365
1366                 $owner = User::getOwnerDataById($uid);
1367                 if (empty($owner)) {
1368                         return;
1369                 }
1370
1371                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1372                 if (!empty($cid)) {
1373                         self::switchContact($cid);
1374                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1375                 }
1376
1377                 $item = [
1378                         'author-id' => Contact::getIdForURL($activity['actor']),
1379                         'author-link' => $activity['actor'],
1380                 ];
1381
1382                 // Ensure that the contact has got the right network type
1383                 self::switchContact($item['author-id']);
1384
1385                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1386                 if ($result === true) {
1387                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1388                 }
1389
1390                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1391                 if (empty($cid)) {
1392                         return;
1393                 }
1394
1395                 if ($result && DI::config()->get('system', 'transmit_pending_events') && ($owner['contact-type'] == Contact::TYPE_COMMUNITY)) {
1396                         self::transmitPendingEvents($cid, $owner['uid']);
1397                 }
1398
1399                 if (empty($contact)) {
1400                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1401                 }
1402                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1403                 Queue::remove($activity);
1404         }
1405
1406         /**
1407          * Transmit pending events to the new follower
1408          *
1409          * @param integer $cid Contact id
1410          * @param integer $uid User id
1411          * @return void
1412          */
1413         private static function transmitPendingEvents(int $cid, int $uid)
1414         {
1415                 $account = DBA::selectFirst('account-user-view', ['ap-inbox', 'ap-sharedinbox'], ['id' => $cid]);
1416                 $inbox = $account['ap-sharedinbox'] ?: $account['ap-inbox'];
1417
1418                 $events = DBA::select('event', ['id'], ["`uid` = ? AND `start` > ? AND `type` != ?", $uid, DateTimeFormat::utcNow(), 'birthday']);
1419                 while ($event = DBA::fetch($events)) {
1420                         $post = Post::selectFirst(['id', 'uri-id', 'created'], ['event-id' => $event['id']]);
1421                         if (empty($post)) {
1422                                 continue;
1423                         }
1424                         if (DI::config()->get('system', 'bulk_delivery')) {
1425                                 Post\Delivery::add($post['uri-id'], $uid, $inbox, $post['created'], Delivery::POST, [$cid]);
1426                                 Worker::add(PRIORITY_HIGH, 'APDelivery', '', 0, $inbox, 0);
1427                         } else {
1428                                 Worker::add(PRIORITY_HIGH, 'APDelivery', Delivery::POST, $post['id'], $inbox, $uid, [$cid], $post['uri-id']);
1429                         }
1430                 }
1431         }
1432
1433         /**
1434          * Update the given profile
1435          *
1436          * @param array $activity
1437          * @throws \Exception
1438          */
1439         public static function updatePerson(array $activity)
1440         {
1441                 if (empty($activity['object_id'])) {
1442                         return;
1443                 }
1444
1445                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1446                 Contact::updateFromProbeByURL($activity['object_id']);
1447                 Queue::remove($activity);
1448         }
1449
1450         /**
1451          * Delete the given profile
1452          *
1453          * @param array $activity
1454          * @return void
1455          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1456          */
1457         public static function deletePerson(array $activity)
1458         {
1459                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1460                         Logger::info('Empty object id or actor.');
1461                         return;
1462                 }
1463
1464                 if ($activity['object_id'] != $activity['actor']) {
1465                         Logger::info('Object id does not match actor.');
1466                         return;
1467                 }
1468
1469                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1470                 while ($contact = DBA::fetch($contacts)) {
1471                         Contact::remove($contact['id']);
1472                 }
1473                 DBA::close($contacts);
1474
1475                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1476                 Queue::remove($activity);
1477         }
1478
1479         /**
1480          * Blocks the user by the contact
1481          *
1482          * @param array $activity
1483          * @return void
1484          * @throws \Exception
1485          */
1486         public static function blockAccount(array $activity)
1487         {
1488                 $cid = Contact::getIdForURL($activity['actor']);
1489                 if (empty($cid)) {
1490                         return;
1491                 }
1492
1493                 $uid = User::getIdForURL($activity['object_id']);
1494                 if (empty($uid)) {
1495                         return;
1496                 }
1497
1498                 Contact\User::setIsBlocked($cid, $uid, true);
1499
1500                 Logger::info('Contact blocked user', ['contact' => $cid, 'user' => $uid]);
1501                 Queue::remove($activity);
1502         }
1503
1504         /**
1505          * Unblocks the user by the contact
1506          *
1507          * @param array $activity
1508          * @return void
1509          * @throws \Exception
1510          */
1511         public static function unblockAccount(array $activity)
1512         {
1513                 $cid = Contact::getIdForURL($activity['actor']);
1514                 if (empty($cid)) {
1515                         return;
1516                 }
1517
1518                 $uid = User::getIdForURL($activity['object_object']);
1519                 if (empty($uid)) {
1520                         return;
1521                 }
1522
1523                 Contact\User::setIsBlocked($cid, $uid, false);
1524
1525                 Logger::info('Contact unblocked user', ['contact' => $cid, 'user' => $uid]);
1526                 Queue::remove($activity);
1527         }
1528
1529         /**
1530          * Accept a follow request
1531          *
1532          * @param array $activity
1533          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1534          * @throws \ImagickException
1535          */
1536         public static function acceptFollowUser(array $activity)
1537         {
1538                 $uid = User::getIdForURL($activity['object_actor']);
1539                 if (empty($uid)) {
1540                         return;
1541                 }
1542
1543                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1544                 if (empty($cid)) {
1545                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1546                         return;
1547                 }
1548
1549                 self::switchContact($cid);
1550
1551                 $fields = ['pending' => false];
1552
1553                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1554                 if ($contact['rel'] == Contact::FOLLOWER) {
1555                         $fields['rel'] = Contact::FRIEND;
1556                 }
1557
1558                 $condition = ['id' => $cid];
1559                 Contact::update($fields, $condition);
1560                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1561                 Queue::remove($activity);
1562         }
1563
1564         /**
1565          * Reject a follow request
1566          *
1567          * @param array $activity
1568          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1569          * @throws \ImagickException
1570          */
1571         public static function rejectFollowUser(array $activity)
1572         {
1573                 $uid = User::getIdForURL($activity['object_actor']);
1574                 if (empty($uid)) {
1575                         return;
1576                 }
1577
1578                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1579                 if (empty($cid)) {
1580                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1581                         return;
1582                 }
1583
1584                 self::switchContact($cid);
1585
1586                 $contact = Contact::getById($cid, ['rel']);
1587                 if ($contact['rel'] == Contact::SHARING) {
1588                         Contact::remove($cid);
1589                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1590                 } elseif ($contact['rel'] == Contact::FRIEND) {
1591                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1592                 } else {
1593                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1594                 }
1595                 Queue::remove($activity);
1596         }
1597
1598         /**
1599          * Undo activity like "like" or "dislike"
1600          *
1601          * @param array $activity
1602          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1603          * @throws \ImagickException
1604          */
1605         public static function undoActivity(array $activity)
1606         {
1607                 if (empty($activity['object_id'])) {
1608                         return;
1609                 }
1610
1611                 if (empty($activity['object_actor'])) {
1612                         return;
1613                 }
1614
1615                 $author_id = Contact::getIdForURL($activity['object_actor']);
1616                 if (empty($author_id)) {
1617                         return;
1618                 }
1619
1620                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1621                 Queue::remove($activity);
1622         }
1623
1624         /**
1625          * Activity to remove a follower
1626          *
1627          * @param array $activity
1628          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1629          * @throws \ImagickException
1630          */
1631         public static function undoFollowUser(array $activity)
1632         {
1633                 $uid = User::getIdForURL($activity['object_object']);
1634                 if (empty($uid)) {
1635                         return;
1636                 }
1637
1638                 $owner = User::getOwnerDataById($uid);
1639                 if (empty($owner)) {
1640                         return;
1641                 }
1642
1643                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1644                 if (empty($cid)) {
1645                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1646                         return;
1647                 }
1648
1649                 self::switchContact($cid);
1650
1651                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1652                 if (!DBA::isResult($contact)) {
1653                         return;
1654                 }
1655
1656                 Contact::removeFollower($contact);
1657                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1658                 Queue::remove($activity);
1659         }
1660
1661         /**
1662          * Switches a contact to AP if needed
1663          *
1664          * @param integer $cid Contact ID
1665          * @return void
1666          * @throws \Exception
1667          */
1668         private static function switchContact(int $cid)
1669         {
1670                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1671                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1672                         return;
1673                 }
1674
1675                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1676                 Contact::updateFromProbe($cid);
1677         }
1678
1679         /**
1680          * Collects implicit mentions like:
1681          * - the author of the parent item
1682          * - all the mentioned conversants in the parent item
1683          *
1684          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1685          * @return array
1686          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1687          */
1688         private static function getImplicitMentionList(array $parent): array
1689         {
1690                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1691
1692                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1693
1694                 $implicit_mentions = [];
1695                 if (empty($parent_author['url'])) {
1696                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1697                 } else {
1698                         $implicit_mentions[] = $parent_author['url'];
1699                         $implicit_mentions[] = $parent_author['nurl'];
1700                         $implicit_mentions[] = $parent_author['alias'];
1701                 }
1702
1703                 if (!empty($parent['alias'])) {
1704                         $implicit_mentions[] = $parent['alias'];
1705                 }
1706
1707                 foreach ($parent_terms as $term) {
1708                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1709                         if (!empty($contact['url'])) {
1710                                 $implicit_mentions[] = $contact['url'];
1711                                 $implicit_mentions[] = $contact['nurl'];
1712                                 $implicit_mentions[] = $contact['alias'];
1713                         }
1714                 }
1715
1716                 return $implicit_mentions;
1717         }
1718
1719         /**
1720          * Strips from the body prepended implicit mentions
1721          *
1722          * @param string $body
1723          * @param array $parent
1724          * @return string
1725          */
1726         private static function removeImplicitMentionsFromBody(string $body, array $parent): string
1727         {
1728                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1729                         return $body;
1730                 }
1731
1732                 $potential_mentions = self::getImplicitMentionList($parent);
1733
1734                 $kept_mentions = [];
1735
1736                 // Extract one prepended mention at a time from the body
1737                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1738                         if (!in_array($matches[2], $potential_mentions)) {
1739                                 $kept_mentions[] = $matches[1];
1740                         }
1741
1742                         $body = $matches[3];
1743                 }
1744
1745                 // Re-appending the kept mentions to the body after extraction
1746                 $kept_mentions[] = $body;
1747
1748                 return implode('', $kept_mentions);
1749         }
1750
1751         /**
1752          * Adds links to string mentions
1753          *
1754          * @param string $body
1755          * @param array  $tags
1756          * @return string
1757          */
1758         protected static function addMentionLinks(string $body, array $tags): string
1759         {
1760                 // This prevents links to be added again to Pleroma-style mention links
1761                 $body = self::normalizeMentionLinks($body);
1762
1763                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1764                         foreach ($tags as $tag) {
1765                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1766                                         continue;
1767                                 }
1768
1769                                 $hash = substr($tag['name'], 0, 1);
1770                                 $name = substr($tag['name'], 1);
1771                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1772                                         $hash = '';
1773                                         $name = $tag['name'];
1774                                 }
1775
1776                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1777                         }
1778
1779                         return $body;
1780                 });
1781
1782                 return $body;
1783         }
1784 }