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          * Create an event
 444          *
 445          * @param array $activity Activity array
 446          * @param array $item
 447          *
 448          * @return int event id
 449          * @throws \Exception
 450          */
 451         public static function createEvent($activity, $item)
 452         {
 453                 $event['summary']   = HTML::toBBCode($activity['name'] ?: $activity['summary']);
 454                 $event['desc']      = HTML::toBBCode($activity['content']);
 455                 $event['start']     = $activity['start-time'];
 456                 $event['finish']    = $activity['end-time'];
 457                 $event['nofinish']  = empty($event['finish']);
 458                 $event['location']  = $activity['location'];
 459                 $event['cid']       = $item['contact-id'];
 460                 $event['uid']       = $item['uid'];
 461                 $event['uri']       = $item['uri'];
 462                 $event['edited']    = $item['edited'];
 463                 $event['private']   = $item['private'];
 464                 $event['guid']      = $item['guid'];
 465                 $event['plink']     = $item['plink'];
 466                 $event['network']   = $item['network'];
 467                 $event['protocol']  = $item['protocol'];
 468                 $event['direction'] = $item['direction'];
 469                 $event['source']    = $item['source'];
 470
 471                 $ev = DBA::selectFirst('event', ['id'], ['uri' => $item['uri'], 'uid' => $item['uid']]);
 472                 if (DBA::isResult($ev)) {
 473                         $event['id'] = $ev['id'];
 474                 }
 475
 476                 $event_id = Event::store($event);
 477
 478                 Logger::info('Event was stored', ['id' => $event_id]);
 479
 480                 return $event_id;
 481         }
 482
 483         /**
 484          * Process the content
 485          *
 486          * @param array $activity Activity array
 487          * @param array $item
 488          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 489          * @throws \Exception
 490          */
 491         private static function processContent($activity, $item)
 492         {
 493                 if (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/markdown')) {
 494                         $item['title'] = Markdown::toBBCode($activity['name']);
 495                         $content = Markdown::toBBCode($activity['content']);
 496                 } elseif (!empty($activity['mediatype']) && ($activity['mediatype'] == 'text/bbcode')) {
 497                         $item['title'] = $activity['name'];
 498                         $content = $activity['content'];
 499                 } else {
 500                         // By default assume "text/html"
 501                         $item['title'] = HTML::toBBCode($activity['name']);
 502                         $content = HTML::toBBCode($activity['content']);
 503                 }
 504
 505                 if (!empty($activity['languages'])) {
 506                         $item['language'] = self::processLanguages($activity['languages']);
 507                 }
 508
 509                 if (!empty($activity['emojis'])) {
 510                         $content = self::replaceEmojis($item['uri-id'], $content, $activity['emojis']);
 511                 }
 512
 513                 $content = self::addMentionLinks($content, $activity['tags']);
 514
 515                 if (!empty($activity['source'])) {
 516                         $item['body'] = $activity['source'];
 517                         $item['raw-body'] = $content;
 518                         $item['body'] = Item::improveSharedDataInBody($item);
 519                 } else {
 520                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 521                                 $item_private = !in_array(0, $activity['item_receiver']);
 522                                 $parent = Post::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 523                                 if (!DBA::isResult($parent)) {
 524                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 525                                         return false;
 526                                 }
 527                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 528                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 529                                         return false;
 530                                 }
 531
 532                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 533                         }
 534                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 535                         $item['raw-body'] = $item['body'] = $content;
 536                 }
 537
 538                 self::storeFromBody($item);
 539                 self::storeTags($item['uri-id'], $activity['tags']);
 540
 541                 self::storeReceivers($item['uri-id'], $activity['receiver_urls'] ?? []);
 542
 543                 $item['location'] = $activity['location'];
 544
 545                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 546                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 547                 }
 548
 549                 $item['app'] = $activity['generator'];
 550
 551                 return $item;
 552         }
 553
 554         /**
 555          * Store hashtags and mentions
 556          *
 557          * @param array $item
 558          */
 559         private static function storeFromBody(array $item)
 560         {
 561                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 562                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 563
 564                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 565         }
 566
 567         /**
 568          * Generate a GUID out of an URL of an ActivityPub post.
 569          *
 570          * @param string $url message URL
 571          * @return string with GUID
 572          */
 573         private static function getGUIDByURL(string $url)
 574         {
 575                 $parsed = parse_url($url);
 576
 577                 $host_hash = hash('crc32', $parsed['host']);
 578
 579                 unset($parsed["scheme"]);
 580                 unset($parsed["host"]);
 581
 582                 $path = implode("/", $parsed);
 583
 584                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 585         }
 586
 587         /**
 588          * Checks if an incoming message is wanted
 589          *
 590          * @param array $activity
 591          * @param array $item
 592          * @return boolean Is the message wanted?
 593          */
 594         private static function isSolicitedMessage(array $activity, array $item)
 595         {
 596                 // The checks are split to improve the support when searching why a message was accepted.
 597                 if (count($activity['receiver']) != 1) {
 598                         // The message has more than one receiver, so it is wanted.
 599                         Logger::debug('Message has got several receivers - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 600                         return true;
 601                 }
 602
 603                 if ($item['private'] == Item::PRIVATE) {
 604                         // We only look at public posts here. Private posts are expected to be intentionally posted to the single receiver.
 605                         Logger::debug('Message is private - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 606                         return true;
 607                 }
 608
 609                 if (!empty($activity['from-relay'])) {
 610                         // We check relay posts at another place. When it arrived here, the message is already checked.
 611                         Logger::debug('Message is a relay post that is already checked - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 612                         return true;
 613                 }
 614
 615                 if (in_array($activity['completion-mode'] ?? Receiver::COMPLETION_NONE, [Receiver::COMPLETION_MANUAL, Receiver::COMPLETION_ANNOUCE])) {
 616                         // Manual completions and completions caused by reshares are allowed without any further checks.
 617                         Logger::debug('Message is in completion mode - accepted', ['mode' => $activity['completion-mode'], 'uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 618                         return true;
 619                 }
 620
 621                 if ($item['gravity'] != GRAVITY_PARENT) {
 622                         // We cannot reliably check at this point if a comment or activity belongs to an accepted post or needs to be fetched
 623                         // This can possibly be improved in the future.
 624                         Logger::debug('Message is no parent - accepted', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 625                         return true;
 626                 }
 627
 628                 $tags = array_column(Tag::getByURIId($item['uri-id'], [Tag::HASHTAG]), 'name');
 629                 if (Relay::isSolicitedPost($tags, $item['body'], $item['author-id'], $item['uri'], Protocol::ACTIVITYPUB)) {
 630                         Logger::debug('Post is accepted because of the relay settings', ['uri-id' => $item['uri-id'], 'guid' => $item['guid'], 'url' => $item['uri']]);
 631                         return true;
 632                 } else {
 633                         return false;
 634                 }
 635         }
 636
 637         /**
 638          * Creates an item post
 639          *
 640          * @param array $activity Activity data
 641          * @param array $item     item array
 642          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 643          * @throws \ImagickException
 644          */
 645         public static function postItem(array $activity, array $item)
 646         {
 647                 if (empty($item)) {
 648                         return;
 649                 }
 650
 651                 $stored = false;
 652                 ksort($activity['receiver']);
 653
 654                 if (!self::isSolicitedMessage($activity, $item)) {
 655                         DBA::delete('item-uri', ['id' => $item['uri-id']]);
 656                         return;
 657                 }
 658
 659                 foreach ($activity['receiver'] as $receiver) {
 660                         if ($receiver == -1) {
 661                                 continue;
 662                         }
 663
 664                         $item['uid'] = $receiver;
 665
 666                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 667                         switch($type) {
 668                                 case Receiver::TARGET_TO:
 669                                         $item['post-reason'] = Item::PR_TO;
 670                                         break;
 671                                 case Receiver::TARGET_CC:
 672                                         $item['post-reason'] = Item::PR_CC;
 673                                         break;
 674                                 case Receiver::TARGET_BTO:
 675                                         $item['post-reason'] = Item::PR_BTO;
 676                                         break;
 677                                 case Receiver::TARGET_BCC:
 678                                         $item['post-reason'] = Item::PR_BCC;
 679                                         break;
 680                                 case Receiver::TARGET_FOLLOWER:
 681                                         $item['post-reason'] = Item::PR_FOLLOWER;
 682                                         break;
 683                                 case Receiver::TARGET_ANSWER:
 684                                         $item['post-reason'] = Item::PR_COMMENT;
 685                                         break;
 686                                 case Receiver::TARGET_GLOBAL:
 687                                         $item['post-reason'] = Item::PR_GLOBAL;
 688                                         break;
 689                                 default:
 690                                         $item['post-reason'] = Item::PR_NONE;
 691                         }
 692
 693                         if (!empty($activity['from-relay'])) {
 694                                 $item['post-reason'] = Item::PR_RELAY;
 695                         } elseif (!empty($activity['thread-completion'])) {
 696                                 $item['post-reason'] = Item::PR_FETCHED;
 697                         }
 698
 699                         if ($item['isForum'] ?? false) {
 700                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 701                         } else {
 702                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 703                         }
 704
 705                         if (($receiver != 0) && empty($item['contact-id'])) {
 706                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 707                         }
 708
 709                         if (!empty($activity['directmessage'])) {
 710                                 self::postMail($activity, $item);
 711                                 continue;
 712                         }
 713
 714                         if (!($item['isForum'] ?? false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT) && !Contact::isSharingByURL($activity['author'], $receiver)) {
 715                                 if ($item['post-reason'] == Item::PR_BCC) {
 716                                         Logger::info('Top level post via BCC from a non sharer, ignoring', ['uid' => $receiver, 'contact' => $item['contact-id']]);
 717                                         continue;
 718                                 }
 719
 720                                 if (
 721                                         !empty($activity['thread-children-type'])
 722                                         && in_array($activity['thread-children-type'], Receiver::ACTIVITY_TYPES)
 723                                         && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') != Item::COMPLETION_LIKE
 724                                 ) {
 725                                         Logger::info('Top level post from thread completion from a non sharer had been initiated via an activity, ignoring',
 726                                                 ['type' => $activity['thread-children-type'], 'user' => $item['uid'], 'causer' => $item['causer-link'], 'author' => $activity['author'], 'url' => $item['uri']]);
 727                                         continue;
 728                                 }
 729                         }
 730
 731                         $is_forum = false;
 732
 733                         if ($receiver != 0) {
 734                                 $user = User::getById($receiver, ['account-type']);
 735                                 if (!empty($user['account-type'])) {
 736                                         $is_forum = ($user['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
 737                                 }
 738                         }
 739
 740                         if (!$is_forum && DI::pConfig()->get($receiver, 'system', 'accept_only_sharer') == Item::COMPLETION_NONE && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 741                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 742
 743                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 744                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 745                                 }
 746
 747                                 if ($skip) {
 748                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 749                                         continue;
 750                                 }
 751
 752                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 753                         }
 754
 755                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 756                                 $event_id = self::createEvent($activity, $item);
 757
 758                                 $item = Event::getItemArrayForImportedId($event_id, $item);
 759                         }
 760
 761                         $item_id = Item::insert($item);
 762                         if ($item_id) {
 763                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 764                         } else {
 765                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 766                         }
 767
 768                         if ($item['uid'] == 0) {
 769                                 $stored = $item_id;
 770                         }
 771                 }
 772
 773                 // Store send a follow request for every reshare - but only when the item had been stored
 774                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 775                         $author = APContact::getByURL($item['owner-link'], false);
 776                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 777                         if ($author['type'] != 'Group') {
 778                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 779                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 780                         }
 781                 }
 782         }
 783
 784         /**
 785          * Store tags and mentions into the tag table
 786          *
 787          * @param integer $uriid
 788          * @param array $tags
 789          */
 790         private static function storeTags(int $uriid, array $tags = null)
 791         {
 792                 foreach ($tags as $tag) {
 793                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 794                                 continue;
 795                         }
 796
 797                         $hash = substr($tag['name'], 0, 1);
 798
 799                         if ($tag['type'] == 'Mention') {
 800                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 801                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 802                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 803                                         $tag['name'] = substr($tag['name'], 1);
 804                                 }
 805                                 $type = Tag::IMPLICIT_MENTION;
 806
 807                                 if (!empty($tag['href'])) {
 808                                         $apcontact = APContact::getByURL($tag['href']);
 809                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 810                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 811                                         }
 812                                 }
 813                         } elseif ($tag['type'] == 'Hashtag') {
 814                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 815                                         $tag['name'] = substr($tag['name'], 1);
 816                                 }
 817                                 $type = Tag::HASHTAG;
 818                         }
 819
 820                         if (empty($tag['name'])) {
 821                                 continue;
 822                         }
 823
 824                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 825                 }
 826         }
 827
 828         public static function storeReceivers(int $uriid, array $receivers)
 829         {
 830                 foreach (['as:to' => Tag::TO, 'as:cc' => Tag::CC, 'as:bto' => Tag::BTO, 'as:bcc' => Tag::BCC] as $element => $type) {
 831                         if (!empty($receivers[$element])) {
 832                                 foreach ($receivers[$element] as $receiver) {
 833                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
 834                                                 $name = Receiver::PUBLIC_COLLECTION;
 835                                         } else {
 836                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
 837                                         }
 838                                         Tag::store($uriid, $type, $name, $receiver);
 839                                 }
 840                         }
 841                 }
 842         }
 843
 844         /**
 845          * Creates an mail post
 846          *
 847          * @param array $activity Activity data
 848          * @param array $item     item array
 849          * @return int|bool New mail table row id or false on error
 850          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 851          */
 852         private static function postMail($activity, $item)
 853         {
 854                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 855                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 856                         return false;
 857                 }
 858
 859                 Logger::info('Direct Message', $item);
 860
 861                 $msg = [];
 862                 $msg['uid'] = $item['uid'];
 863
 864                 $msg['contact-id'] = $item['contact-id'];
 865
 866                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 867                 $msg['from-name'] = $contact['name'];
 868                 $msg['from-url'] = $contact['url'];
 869                 $msg['from-photo'] = $contact['photo'];
 870
 871                 $msg['uri'] = $item['uri'];
 872                 $msg['created'] = $item['created'];
 873
 874                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 875                 if (DBA::isResult($parent)) {
 876                         $msg['parent-uri'] = $parent['parent-uri'];
 877                         $msg['title'] = $parent['title'];
 878                 } else {
 879                         $msg['parent-uri'] = $item['thr-parent'];
 880
 881                         if (!empty($item['title'])) {
 882                                 $msg['title'] = $item['title'];
 883                         } elseif (!empty($item['content-warning'])) {
 884                                 $msg['title'] = $item['content-warning'];
 885                         } else {
 886                                 // Trying to generate a title out of the body
 887                                 $title = $item['body'];
 888
 889                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 890                                         $title = $matches[3];
 891                                 }
 892
 893                                 $title = trim(BBCode::toPlaintext($title));
 894
 895                                 if (strlen($title) > 20) {
 896                                         $title = substr($title, 0, 20) . '...';
 897                                 }
 898
 899                                 $msg['title'] = $title;
 900                         }
 901                 }
 902                 $msg['body'] = $item['body'];
 903
 904                 return Mail::insert($msg);
 905         }
 906
 907         /**
 908          * Fetches missing posts
 909          *
 910          * @param string $url         message URL
 911          * @param array  $child       activity array with the child of this message
 912          * @param string $relay_actor Relay actor
 913          * @param int    $completion  Completion mode, see Receiver::COMPLETION_*
 914          * @return string fetched message URL
 915          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 916          */
 917         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '', int $completion = Receiver::COMPLETION_MANUAL)
 918         {
 919                 if (!empty($child['receiver'])) {
 920                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 921                 } else {
 922                         $uid = 0;
 923                 }
 924
 925                 $object = ActivityPub::fetchContent($url, $uid);
 926                 if (empty($object)) {
 927                         Logger::notice('Activity was not fetchable, aborting.', ['url' => $url]);
 928                         return '';
 929                 }
 930
 931                 if (empty($object['id'])) {
 932                         Logger::notice('Activity has got not id, aborting. ', ['url' => $url, 'object' => $object]);
 933                         return '';
 934                 }
 935
 936                 if (!empty($object['actor'])) {
 937                         $object_actor = $object['actor'];
 938                 } elseif (!empty($object['attributedTo'])) {
 939                         $object_actor = $object['attributedTo'];
 940                         if (is_array($object_actor)) {
 941                                 $compacted = JsonLD::compact($object);
 942                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
 943                         }
 944                 } else {
 945                         // Shouldn't happen
 946                         $object_actor = '';
 947                 }
 948
 949                 $signer = [$object_actor];
 950
 951                 if (!empty($child['author'])) {
 952                         $actor = $child['author'];
 953                         $signer[] = $actor;
 954                 } else {
 955                         $actor = $object_actor;
 956                 }
 957
 958                 if (!empty($object['published'])) {
 959                         $published = $object['published'];
 960                 } elseif (!empty($child['published'])) {
 961                         $published = $child['published'];
 962                 } else {
 963                         $published = DateTimeFormat::utcNow();
 964                 }
 965
 966                 $activity = [];
 967                 $activity['@context'] = $object['@context'] ?? ActivityPub::CONTEXT;
 968                 unset($object['@context']);
 969                 $activity['id'] = $object['id'];
 970                 $activity['to'] = $object['to'] ?? [];
 971                 $activity['cc'] = $object['cc'] ?? [];
 972                 $activity['actor'] = $actor;
 973                 $activity['object'] = $object;
 974                 $activity['published'] = $published;
 975                 $activity['type'] = 'Create';
 976
 977                 $ldactivity = JsonLD::compact($activity);
 978
 979                 if (!empty($relay_actor)) {
 980                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 981                         $ldactivity['completion-mode']   = Receiver::COMPLETION_RELAY;
 982                 } elseif (!empty($child['thread-completion'])) {
 983                         $ldactivity['thread-completion'] = $child['thread-completion'];
 984                         $ldactivity['completion-mode']   = $child['completion-mode'] ?? Receiver::COMPLETION_NONE;
 985                 } else {
 986                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
 987                         $ldactivity['completion-mode']   = $completion;
 988                 }
 989
 990                 if (!empty($child['type'])) {
 991                         $ldactivity['thread-children-type'] = $child['type'];
 992                 }
 993
 994                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 995                         return '';
 996                 }
 997
 998                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 999
1000                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
1001
1002                 return $activity['id'];
1003         }
1004
1005         /**
1006          * Test if incoming relay messages should be accepted
1007          *
1008          * @param array $activity activity array
1009          * @param string $id      object ID
1010          * @return boolean true if message is accepted
1011          */
1012         private static function acceptIncomingMessage(array $activity, string $id)
1013         {
1014                 if (empty($activity['as:object'])) {
1015                         Logger::info('No object field in activity - accepted', ['id' => $id]);
1016                         return true;
1017                 }
1018
1019                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
1020                 $uriid = ItemURI::getIdByURI($replyto);
1021                 if (Post::exists(['uri-id' => $uriid])) {
1022                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'uri-id' => $uriid, 'replyto' => $replyto]);
1023                         return true;
1024                 }
1025
1026                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
1027                 $authorid = Contact::getIdForURL($attributed_to);
1028
1029                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
1030
1031                 $messageTags = [];
1032                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
1033                 if (!empty($tags)) {
1034                         foreach ($tags as $tag) {
1035                                 if ($tag['type'] != 'Hashtag') {
1036                                         continue;
1037                                 }
1038                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
1039                         }
1040                 }
1041
1042                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
1043         }
1044
1045         /**
1046          * perform a "follow" request
1047          *
1048          * @param array $activity
1049          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1050          * @throws \ImagickException
1051          */
1052         public static function followUser($activity)
1053         {
1054                 $uid = User::getIdForURL($activity['object_id']);
1055                 if (empty($uid)) {
1056                         return;
1057                 }
1058
1059                 $owner = User::getOwnerDataById($uid);
1060                 if (empty($owner)) {
1061                         return;
1062                 }
1063
1064                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1065                 if (!empty($cid)) {
1066                         self::switchContact($cid);
1067                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1068                 }
1069
1070                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
1071                         'author-link' => $activity['actor']];
1072
1073                 // Ensure that the contact has got the right network type
1074                 self::switchContact($item['author-id']);
1075
1076                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
1077                 if ($result === true) {
1078                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
1079                 }
1080
1081                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1082                 if (empty($cid)) {
1083                         return;
1084                 }
1085
1086                 if (empty($contact)) {
1087                         Contact::update(['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
1088                 }
1089
1090                 Logger::notice('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1091         }
1092
1093         /**
1094          * Update the given profile
1095          *
1096          * @param array $activity
1097          * @throws \Exception
1098          */
1099         public static function updatePerson($activity)
1100         {
1101                 if (empty($activity['object_id'])) {
1102                         return;
1103                 }
1104
1105                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
1106                 Contact::updateFromProbeByURL($activity['object_id']);
1107         }
1108
1109         /**
1110          * Delete the given profile
1111          *
1112          * @param array $activity
1113          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1114          */
1115         public static function deletePerson($activity)
1116         {
1117                 if (empty($activity['object_id']) || empty($activity['actor'])) {
1118                         Logger::info('Empty object id or actor.');
1119                         return;
1120                 }
1121
1122                 if ($activity['object_id'] != $activity['actor']) {
1123                         Logger::info('Object id does not match actor.');
1124                         return;
1125                 }
1126
1127                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
1128                 while ($contact = DBA::fetch($contacts)) {
1129                         Contact::remove($contact['id']);
1130                 }
1131                 DBA::close($contacts);
1132
1133                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
1134         }
1135
1136         /**
1137          * Accept a follow request
1138          *
1139          * @param array $activity
1140          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1141          * @throws \ImagickException
1142          */
1143         public static function acceptFollowUser($activity)
1144         {
1145                 $uid = User::getIdForURL($activity['object_actor']);
1146                 if (empty($uid)) {
1147                         return;
1148                 }
1149
1150                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1151                 if (empty($cid)) {
1152                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1153                         return;
1154                 }
1155
1156                 self::switchContact($cid);
1157
1158                 $fields = ['pending' => false];
1159
1160                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1161                 if ($contact['rel'] == Contact::FOLLOWER) {
1162                         $fields['rel'] = Contact::FRIEND;
1163                 }
1164
1165                 $condition = ['id' => $cid];
1166                 Contact::update($fields, $condition);
1167                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1168         }
1169
1170         /**
1171          * Reject a follow request
1172          *
1173          * @param array $activity
1174          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1175          * @throws \ImagickException
1176          */
1177         public static function rejectFollowUser($activity)
1178         {
1179                 $uid = User::getIdForURL($activity['object_actor']);
1180                 if (empty($uid)) {
1181                         return;
1182                 }
1183
1184                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1185                 if (empty($cid)) {
1186                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1187                         return;
1188                 }
1189
1190                 self::switchContact($cid);
1191
1192                 $contact = Contact::getById($cid, ['rel']);
1193                 if ($contact['rel'] == Contact::SHARING) {
1194                         Contact::remove($cid);
1195                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1196                 } elseif ($contact['rel'] == Contact::FRIEND) {
1197                         Contact::update(['rel' => Contact::FOLLOWER], ['id' => $cid]);
1198                 } else {
1199                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1200                 }
1201         }
1202
1203         /**
1204          * Undo activity like "like" or "dislike"
1205          *
1206          * @param array $activity
1207          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1208          * @throws \ImagickException
1209          */
1210         public static function undoActivity($activity)
1211         {
1212                 if (empty($activity['object_id'])) {
1213                         return;
1214                 }
1215
1216                 if (empty($activity['object_actor'])) {
1217                         return;
1218                 }
1219
1220                 $author_id = Contact::getIdForURL($activity['object_actor']);
1221                 if (empty($author_id)) {
1222                         return;
1223                 }
1224
1225                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1226         }
1227
1228         /**
1229          * Activity to remove a follower
1230          *
1231          * @param array $activity
1232          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1233          * @throws \ImagickException
1234          */
1235         public static function undoFollowUser($activity)
1236         {
1237                 $uid = User::getIdForURL($activity['object_object']);
1238                 if (empty($uid)) {
1239                         return;
1240                 }
1241
1242                 $owner = User::getOwnerDataById($uid);
1243                 if (empty($owner)) {
1244                         return;
1245                 }
1246
1247                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1248                 if (empty($cid)) {
1249                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1250                         return;
1251                 }
1252
1253                 self::switchContact($cid);
1254
1255                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1256                 if (!DBA::isResult($contact)) {
1257                         return;
1258                 }
1259
1260                 Contact::removeFollower($contact);
1261                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1262         }
1263
1264         /**
1265          * Switches a contact to AP if needed
1266          *
1267          * @param integer $cid Contact ID
1268          * @throws \Exception
1269          */
1270         private static function switchContact($cid)
1271         {
1272                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1273                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1274                         return;
1275                 }
1276
1277                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1278                 Contact::updateFromProbe($cid);
1279         }
1280
1281         /**
1282          * Collects implicit mentions like:
1283          * - the author of the parent item
1284          * - all the mentioned conversants in the parent item
1285          *
1286          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1287          * @return array
1288          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1289          */
1290         private static function getImplicitMentionList(array $parent)
1291         {
1292                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1293
1294                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1295
1296                 $implicit_mentions = [];
1297                 if (empty($parent_author['url'])) {
1298                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'parent-id' => $parent['id']]);
1299                 } else {
1300                         $implicit_mentions[] = $parent_author['url'];
1301                         $implicit_mentions[] = $parent_author['nurl'];
1302                         $implicit_mentions[] = $parent_author['alias'];
1303                 }
1304
1305                 if (!empty($parent['alias'])) {
1306                         $implicit_mentions[] = $parent['alias'];
1307                 }
1308
1309                 foreach ($parent_terms as $term) {
1310                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1311                         if (!empty($contact['url'])) {
1312                                 $implicit_mentions[] = $contact['url'];
1313                                 $implicit_mentions[] = $contact['nurl'];
1314                                 $implicit_mentions[] = $contact['alias'];
1315                         }
1316                 }
1317
1318                 return $implicit_mentions;
1319         }
1320
1321         /**
1322          * Strips from the body prepended implicit mentions
1323          *
1324          * @param string $body
1325          * @param array $parent
1326          * @return string
1327          */
1328         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1329         {
1330                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1331                         return $body;
1332                 }
1333
1334                 $potential_mentions = self::getImplicitMentionList($parent);
1335
1336                 $kept_mentions = [];
1337
1338                 // Extract one prepended mention at a time from the body
1339                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1340                         if (!in_array($matches[2], $potential_mentions)) {
1341                                 $kept_mentions[] = $matches[1];
1342                         }
1343
1344                         $body = $matches[3];
1345                 }
1346
1347                 // Re-appending the kept mentions to the body after extraction
1348                 $kept_mentions[] = $body;
1349
1350                 return implode('', $kept_mentions);
1351         }
1352
1353         /**
1354          * Adds links to string mentions
1355          *
1356          * @param string $body
1357          * @param array  $tags
1358          * @return string
1359          */
1360         protected static function addMentionLinks(string $body, array $tags): string
1361         {
1362                 // This prevents links to be added again to Pleroma-style mention links
1363                 $body = self::normalizeMentionLinks($body);
1364
1365                 $body = BBCode::performWithEscapedTags($body, ['url'], function ($body) use ($tags) {
1366                         foreach ($tags as $tag) {
1367                                 if (empty($tag['name']) || empty($tag['type']) || empty($tag['href']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
1368                                         continue;
1369                                 }
1370
1371                                 $hash = substr($tag['name'], 0, 1);
1372                                 $name = substr($tag['name'], 1);
1373                                 if (!in_array($hash, Tag::TAG_CHARACTER)) {
1374                                         $hash = '';
1375                                         $name = $tag['name'];
1376                                 }
1377
1378                                 $body = str_replace($tag['name'], $hash . '[url=' . $tag['href'] . ']' . $name . '[/url]', $body);
1379                         }
1380
1381                         return $body;
1382                 });
1383
1384                 return $body;
1385         }
1386 }