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