src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   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\PageInfo;
  25 use Friendica\Content\Text\BBCode;
  26 use Friendica\Content\Text\HTML;
  27 use Friendica\Core\Logger;
  28 use Friendica\Core\Protocol;
  29 use Friendica\Database\DBA;
  30 use Friendica\DI;
  31 use Friendica\Model\APContact;
  32 use Friendica\Model\Contact;
  33 use Friendica\Model\Conversation;
  34 use Friendica\Model\Event;
  35 use Friendica\Model\Item;
  36 use Friendica\Model\ItemURI;
  37 use Friendica\Model\Mail;
  38 use Friendica\Model\Tag;
  39 use Friendica\Model\User;
  40 use Friendica\Model\Post;
  41 use Friendica\Protocol\Activity;
  42 use Friendica\Protocol\ActivityPub;
  43 use Friendica\Protocol\Relay;
  44 use Friendica\Util\DateTimeFormat;
  45 use Friendica\Util\JsonLD;
  46 use Friendica\Util\Strings;
  47
  48 /**
  49  * ActivityPub Processor Protocol class
  50  */
  51 class Processor
  52 {
  53         /**
  54          * Converts mentions from Pleroma into the Friendica format
  55          *
  56          * @param string $body
  57          *
  58          * @return string converted body
  59          */
  60         private static function convertMentions($body)
  61         {
  62                 $URLSearchString = "^\[\]";
  63                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
  64
  65                 return $body;
  66         }
  67
  68         /**
  69          * Replaces emojis in the body
  70          *
  71          * @param array $emojis
  72          * @param string $body
  73          *
  74          * @return string with replaced emojis
  75          */
  76         private static function replaceEmojis($body, array $emojis)
  77         {
  78                 foreach ($emojis as $emoji) {
  79                         $replace = '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
  80                         $body = str_replace($emoji['name'], $replace, $body);
  81                 }
  82                 return $body;
  83         }
  84
  85         /**
  86          * Store attached media files in the post-media table
  87          *
  88          * @param int $uriid
  89          * @param array $attachment
  90          * @return void
  91          */
  92         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
  93         {
  94                 if (empty($attachment['url'])) {
  95                         return;
  96                 }
  97
  98                 $data = ['uri-id' => $uriid];
  99
 100                 $filetype = strtolower(substr($attachment['mediaType'], 0, strpos($attachment['mediaType'], '/')));
 101                 if ($filetype == 'image') {
 102                         $data['type'] = Post\Media::IMAGE;
 103                 } elseif ($filetype == 'video') {
 104                         $data['type'] = Post\Media::VIDEO;
 105                 } elseif ($filetype == 'audio') {
 106                         $data['type'] = Post\Media::AUDIO;
 107                 } elseif (in_array($attachment['mediaType'], ['application/x-bittorrent', 'application/x-bittorrent;x-scheme-handler/magnet'])) {
 108                         $data['type'] = Post\Media::TORRENT;
 109                 } else {
 110                         Logger::info('Unknown type', ['attachment' => $attachment]);
 111                         return;
 112                 }
 113
 114                 $data['url'] = $attachment['url'];
 115                 $data['mimetype'] = $attachment['mediaType'];
 116                 $data['height'] = $attachment['height'] ?? null;
 117                 $data['size'] = $attachment['size'] ?? null;
 118                 $data['preview'] = $attachment['image'] ?? null;
 119                 $data['description'] = $attachment['name'] ?? null;
 120
 121                 Post\Media::insert($data);
 122         }
 123
 124         /**
 125          * Add attachment data to the item array
 126          *
 127          * @param array   $activity
 128          * @param array   $item
 129          *
 130          * @return array array
 131          */
 132         private static function constructAttachList($activity, $item)
 133         {
 134                 if (empty($activity['attachments'])) {
 135                         return $item;
 136                 }
 137
 138                 $item['attach'] = '';
 139
 140                 foreach ($activity['attachments'] as $attach) {
 141                         switch ($attach['type']) {
 142                                 case 'link':
 143                                         $data = [
 144                                                 'url'      => $attach['url'],
 145                                                 'type'     => $attach['type'],
 146                                                 'title'    => $attach['title'] ?? '',
 147                                                 'text'     => $attach['desc']  ?? '',
 148                                                 'image'    => $attach['image'] ?? '',
 149                                                 'images'   => [],
 150                                                 'keywords' => [],
 151                                         ];
 152                                         $item['body'] = PageInfo::appendDataToBody($item['body'], $data);
 153                                         break;
 154                                 default:
 155                                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 156
 157                                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 158                                         if ($filetype == 'image') {
 159                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 160                                                         continue 2;
 161                                                 }
 162
 163                                                 $item['body'] .= "\n";
 164
 165                                                 // image is the preview/thumbnail URL
 166                                                 if (!empty($attach['image'])) {
 167                                                         $item['body'] .= '[url=' . $attach['url'] . ']';
 168                                                         $attach['url'] = $attach['image'];
 169                                                 }
 170
 171                                                 if (empty($attach['name'])) {
 172                                                         $item['body'] .= '[img]' . $attach['url'] . '[/img]';
 173                                                 } else {
 174                                                         $item['body'] .= '[img=' . $attach['url'] . ']' . $attach['name'] . '[/img]';
 175                                                 }
 176
 177                                                 if (!empty($attach['image'])) {
 178                                                         $item['body'] .= '[/url]';
 179                                                 }
 180                                         } elseif ($filetype == 'audio') {
 181                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 182                                                         continue 2;
 183                                                 }
 184
 185                                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 186                                         } elseif ($filetype == 'video') {
 187                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 188                                                         continue 2;
 189                                                 }
 190
 191                                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 192                                         } else {
 193                                                 if (!empty($item['attach'])) {
 194                                                         $item['attach'] .= ',';
 195                                                 } else {
 196                                                         $item['attach'] = '';
 197                                                 }
 198
 199                                                 $item['attach'] .= Post\Media::getAttachElement($attach['url'],
 200                                                         $attach['length'] ?? 0, $attach['mediaType'], $attach['name'] ?? '');
 201                                         }
 202                         }
 203                 }
 204
 205                 return $item;
 206         }
 207
 208         /**
 209          * Updates a message
 210          *
 211          * @param array $activity Activity array
 212          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 213          */
 214         public static function updateItem($activity)
 215         {
 216                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 217                 if (!DBA::isResult($item)) {
 218                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 219                         $item = self::createItem($activity);
 220                         self::postItem($activity, $item);
 221                         return;
 222                 }
 223
 224                 $item['changed'] = DateTimeFormat::utcNow();
 225                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 226
 227                 $item = self::processContent($activity, $item);
 228
 229                 $item = self::constructAttachList($activity, $item);
 230
 231                 if (empty($item)) {
 232                         return;
 233                 }
 234
 235                 Item::update($item, ['uri' => $activity['id']]);
 236         }
 237
 238         /**
 239          * Prepares data for a message
 240          *
 241          * @param array $activity Activity array
 242          * @return array Internal item
 243          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 244          * @throws \ImagickException
 245          */
 246         public static function createItem($activity)
 247         {
 248                 $item = [];
 249                 $item['verb'] = Activity::POST;
 250                 $item['thr-parent'] = $activity['reply-to-id'];
 251
 252                 if ($activity['reply-to-id'] == $activity['id']) {
 253                         $item['gravity'] = GRAVITY_PARENT;
 254                         $item['object-type'] = Activity\ObjectType::NOTE;
 255                 } else {
 256                         $item['gravity'] = GRAVITY_COMMENT;
 257                         $item['object-type'] = Activity\ObjectType::COMMENT;
 258                 }
 259
 260                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 261                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 262                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 263                 }
 264
 265                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 266
 267                 /// @todo What to do with $activity['context']?
 268                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 269                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 270                         return [];
 271                 }
 272
 273                 $item['network'] = Protocol::ACTIVITYPUB;
 274                 $item['author-link'] = $activity['author'];
 275                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 276                 $item['owner-link'] = $activity['actor'];
 277                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 278
 279                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 280                         $item['private'] = Item::UNLISTED;
 281                 } elseif (in_array(0, $activity['receiver'])) {
 282                         $item['private'] = Item::PUBLIC;
 283                 } else {
 284                         $item['private'] = Item::PRIVATE;
 285                 }
 286
 287                 if (!empty($activity['raw'])) {
 288                         $item['source'] = $activity['raw'];
 289                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 290                         $item['conversation-href'] = $activity['context'] ?? '';
 291                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 292
 293                         if (isset($activity['push'])) {
 294                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 295                         }
 296                 }
 297
 298                 $item['isForum'] = false;
 299
 300                 if (!empty($activity['thread-completion'])) {
 301                         if ($activity['thread-completion'] != $item['owner-id']) {
 302                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 303                                 $item['causer-link'] = $actor['url'];
 304                                 $item['causer-id'] = $activity['thread-completion'];
 305                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 306                         } else {
 307                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 308                                 $item['causer-link'] = $item['owner-link'];
 309                                 $item['causer-id'] = $item['owner-id'];
 310                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 311                         }
 312
 313                         $item['owner-link'] = $item['author-link'];
 314                         $item['owner-id'] = $item['author-id'];
 315                 } else {
 316                         $actor = APContact::getByURL($item['owner-link'], false);
 317                         $item['isForum'] = ($actor['type'] == 'Group');
 318                 }
 319
 320                 $item['uri'] = $activity['id'];
 321
 322                 $item['created'] = DateTimeFormat::utc($activity['published']);
 323                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 324                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 325                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 326
 327                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 328
 329                 $item = self::processContent($activity, $item);
 330                 if (empty($item)) {
 331                         Logger::info('Message was not processed');
 332                         return [];
 333                 }
 334
 335                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 336
 337                 $item = self::constructAttachList($activity, $item);
 338
 339                 return $item;
 340         }
 341
 342         /**
 343          * Delete items
 344          *
 345          * @param array $activity
 346          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 347          * @throws \ImagickException
 348          */
 349         public static function deleteItem($activity)
 350         {
 351                 $owner = Contact::getIdForURL($activity['actor']);
 352
 353                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 354                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 355         }
 356
 357         /**
 358          * Prepare the item array for an activity
 359          *
 360          * @param array $activity Activity array
 361          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 362          * @throws \ImagickException
 363          */
 364         public static function addTag($activity)
 365         {
 366                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 367                         return;
 368                 }
 369
 370                 foreach ($activity['receiver'] as $receiver) {
 371                         $item = Item::selectFirst(['id', 'uri-id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 372                         if (!DBA::isResult($item)) {
 373                                 // We don't fetch missing content for this purpose
 374                                 continue;
 375                         }
 376
 377                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 378                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 379                                 continue;
 380                         }
 381
 382                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 383                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 384                 }
 385         }
 386
 387         /**
 388          * Prepare the item array for an activity
 389          *
 390          * @param array  $activity Activity array
 391          * @param string $verb     Activity verb
 392          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 393          * @throws \ImagickException
 394          */
 395         public static function createActivity($activity, $verb)
 396         {
 397                 $item = self::createItem($activity);
 398                 $item['verb'] = $verb;
 399                 $item['thr-parent'] = $activity['object_id'];
 400                 $item['gravity'] = GRAVITY_ACTIVITY;
 401                 $item['object-type'] = Activity\ObjectType::NOTE;
 402
 403                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 404
 405                 self::postItem($activity, $item);
 406         }
 407
 408         /**
 409          * Create an event
 410          *
 411          * @param array $activity Activity array
 412          * @param array $item
 413          * @throws \Exception
 414          */
 415         public static function createEvent($activity, $item)
 416         {
 417                 $event['summary']  = HTML::toBBCode($activity['name']);
 418                 $event['desc']     = HTML::toBBCode($activity['content']);
 419                 $event['start']    = $activity['start-time'];
 420                 $event['finish']   = $activity['end-time'];
 421                 $event['nofinish'] = empty($event['finish']);
 422                 $event['location'] = $activity['location'];
 423                 $event['adjust']   = true;
 424                 $event['cid']      = $item['contact-id'];
 425                 $event['uid']      = $item['uid'];
 426                 $event['uri']      = $item['uri'];
 427                 $event['edited']   = $item['edited'];
 428                 $event['private']  = $item['private'];
 429                 $event['guid']     = $item['guid'];
 430                 $event['plink']    = $item['plink'];
 431
 432                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 433                 $ev = DBA::selectFirst('event', ['id'], $condition);
 434                 if (DBA::isResult($ev)) {
 435                         $event['id'] = $ev['id'];
 436                 }
 437
 438                 $event_id = Event::store($event);
 439                 Logger::info('Event was stored', ['id' => $event_id]);
 440         }
 441
 442         /**
 443          * Process the content
 444          *
 445          * @param array $activity Activity array
 446          * @param array $item
 447          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 448          * @throws \Exception
 449          */
 450         private static function processContent($activity, $item)
 451         {
 452                 $item['title'] = HTML::toBBCode($activity['name']);
 453
 454                 $content = HTML::toBBCode($activity['content']);
 455
 456                 if (!empty($activity['emojis'])) {
 457                         $content = self::replaceEmojis($content, $activity['emojis']);
 458                 }
 459
 460                 $content = self::convertMentions($content);
 461
 462                 if (!empty($activity['source'])) {
 463                         $item['body'] = $activity['source'];
 464                         $item['raw-body'] = $content;
 465                 } else {
 466                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 467                                 $item_private = !in_array(0, $activity['item_receiver']);
 468                                 $parent = Item::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 469                                 if (!DBA::isResult($parent)) {
 470                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 471                                         return false;
 472                                 }
 473                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 474                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 475                                         return false;
 476                                 }
 477
 478                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 479                         }
 480                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 481                         $item['raw-body'] = $item['body'] = $content;
 482                 }
 483
 484                 self::storeFromBody($item);
 485                 self::storeTags($item['uri-id'], $activity['tags']);
 486
 487                 $item['location'] = $activity['location'];
 488
 489                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 490                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 491                 }
 492
 493                 $item['app'] = $activity['generator'];
 494
 495                 return $item;
 496         }
 497
 498         /**
 499          * Store hashtags and mentions
 500          *
 501          * @param array $item
 502          */
 503         private static function storeFromBody(array $item)
 504         {
 505                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 506                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 507
 508                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 509         }
 510
 511         /**
 512          * Generate a GUID out of an URL
 513          *
 514          * @param string $url message URL
 515          * @return string with GUID
 516          */
 517         private static function getGUIDByURL(string $url)
 518         {
 519                 $parsed = parse_url($url);
 520
 521                 $host_hash = hash('crc32', $parsed['host']);
 522
 523                 unset($parsed["scheme"]);
 524                 unset($parsed["host"]);
 525
 526                 $path = implode("/", $parsed);
 527
 528                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 529         }
 530
 531         /**
 532          * Creates an item post
 533          *
 534          * @param array $activity Activity data
 535          * @param array $item     item array
 536          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 537          * @throws \ImagickException
 538          */
 539         public static function postItem(array $activity, array $item)
 540         {
 541                 if (empty($item)) {
 542                         return;
 543                 }
 544
 545                 $stored = false;
 546                 ksort($activity['receiver']);
 547
 548                 foreach ($activity['receiver'] as $receiver) {
 549                         if ($receiver == -1) {
 550                                 continue;
 551                         }
 552
 553                         $item['uid'] = $receiver;
 554
 555                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 556                         switch($type) {
 557                                 case Receiver::TARGET_TO:
 558                                         $item['post-type'] = Item::PT_TO;
 559                                         break;
 560                                 case Receiver::TARGET_CC:
 561                                         $item['post-type'] = Item::PT_CC;
 562                                         break;
 563                                 case Receiver::TARGET_BTO:
 564                                         $item['post-type'] = Item::PT_BTO;
 565                                         break;
 566                                 case Receiver::TARGET_BCC:
 567                                         $item['post-type'] = Item::PT_BCC;
 568                                         break;
 569                                 case Receiver::TARGET_FOLLOWER:
 570                                         $item['post-type'] = Item::PT_FOLLOWER;
 571                                         break;
 572                                 case Receiver::TARGET_ANSWER:
 573                                         $item['post-type'] = Item::PT_COMMENT;
 574                                         break;
 575                                 case Receiver::TARGET_GLOBAL:
 576                                         $item['post-type'] = Item::PT_GLOBAL;
 577                                         break;
 578                                 default:
 579                                         $item['post-type'] = Item::PT_ARTICLE;
 580                         }
 581
 582                         if (!empty($activity['from-relay'])) {
 583                                 $item['post-type'] = Item::PT_RELAY;
 584                         } elseif (!empty($activity['thread-completion'])) {
 585                                 $item['post-type'] = Item::PT_FETCHED;
 586                         }
 587
 588                         if ($item['isForum'] ?? false) {
 589                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 590                         } else {
 591                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 592                         }
 593
 594                         if (($receiver != 0) && empty($item['contact-id'])) {
 595                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 596                         }
 597
 598                         if (!empty($activity['directmessage'])) {
 599                                 self::postMail($activity, $item);
 600                                 continue;
 601                         }
 602
 603                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 604                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 605
 606                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 607                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 608                                 }
 609
 610                                 if ($skip) {
 611                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 612                                         continue;
 613                                 }
 614
 615                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 616                         }
 617
 618                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 619                                 self::createEvent($activity, $item);
 620                         }
 621
 622                         $item_id = Item::insert($item);
 623                         if ($item_id) {
 624                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 625                         } else {
 626                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 627                         }
 628
 629                         if ($item['uid'] == 0) {
 630                                 $stored = $item_id;
 631                         }
 632                 }
 633
 634                 // Store send a follow request for every reshare - but only when the item had been stored
 635                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 636                         $author = APContact::getByURL($item['owner-link'], false);
 637                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 638                         if ($author['type'] != 'Group') {
 639                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 640                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 641                         }
 642                 }
 643         }
 644
 645         /**
 646          * Store tags and mentions into the tag table
 647          *
 648          * @param integer $uriid
 649          * @param array $tags
 650          */
 651         private static function storeTags(int $uriid, array $tags = null)
 652         {
 653                 foreach ($tags as $tag) {
 654                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 655                                 continue;
 656                         }
 657
 658                         $hash = substr($tag['name'], 0, 1);
 659
 660                         if ($tag['type'] == 'Mention') {
 661                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 662                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 663                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 664                                         $tag['name'] = substr($tag['name'], 1);
 665                                 }
 666                                 $type = Tag::IMPLICIT_MENTION;
 667
 668                                 if (!empty($tag['href'])) {
 669                                         $apcontact = APContact::getByURL($tag['href']);
 670                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 671                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 672                                         }
 673                                 }
 674                         } elseif ($tag['type'] == 'Hashtag') {
 675                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 676                                         $tag['name'] = substr($tag['name'], 1);
 677                                 }
 678                                 $type = Tag::HASHTAG;
 679                         }
 680
 681                         if (empty($tag['name'])) {
 682                                 continue;
 683                         }
 684
 685                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 686                 }
 687         }
 688
 689         /**
 690          * Creates an mail post
 691          *
 692          * @param array $activity Activity data
 693          * @param array $item     item array
 694          * @return int|bool New mail table row id or false on error
 695          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 696          */
 697         private static function postMail($activity, $item)
 698         {
 699                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 700                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 701                         return false;
 702                 }
 703
 704                 Logger::info('Direct Message', $item);
 705
 706                 $msg = [];
 707                 $msg['uid'] = $item['uid'];
 708
 709                 $msg['contact-id'] = $item['contact-id'];
 710
 711                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 712                 $msg['from-name'] = $contact['name'];
 713                 $msg['from-url'] = $contact['url'];
 714                 $msg['from-photo'] = $contact['photo'];
 715
 716                 $msg['uri'] = $item['uri'];
 717                 $msg['created'] = $item['created'];
 718
 719                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 720                 if (DBA::isResult($parent)) {
 721                         $msg['parent-uri'] = $parent['parent-uri'];
 722                         $msg['title'] = $parent['title'];
 723                 } else {
 724                         $msg['parent-uri'] = $item['thr-parent'];
 725
 726                         if (!empty($item['title'])) {
 727                                 $msg['title'] = $item['title'];
 728                         } elseif (!empty($item['content-warning'])) {
 729                                 $msg['title'] = $item['content-warning'];
 730                         } else {
 731                                 // Trying to generate a title out of the body
 732                                 $title = $item['body'];
 733
 734                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 735                                         $title = $matches[3];
 736                                 }
 737
 738                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, BBCode::API, true), 0));
 739
 740                                 if (strlen($title) > 20) {
 741                                         $title = substr($title, 0, 20) . '...';
 742                                 }
 743
 744                                 $msg['title'] = $title;
 745                         }
 746                 }
 747                 $msg['body'] = $item['body'];
 748
 749                 return Mail::insert($msg);
 750         }
 751
 752         /**
 753          * Fetches missing posts
 754          *
 755          * @param string $url         message URL
 756          * @param array  $child       activity array with the child of this message
 757          * @param string $relay_actor Relay actor
 758          * @return string fetched message URL
 759          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 760          */
 761         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
 762         {
 763                 if (!empty($child['receiver'])) {
 764                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 765                 } else {
 766                         $uid = 0;
 767                 }
 768
 769                 $object = ActivityPub::fetchContent($url, $uid);
 770                 if (empty($object)) {
 771                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 772                         return '';
 773                 }
 774
 775                 if (empty($object['id'])) {
 776                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 777                         return '';
 778                 }
 779
 780                 if (!empty($object['actor'])) {
 781                         $object_actor = $object['actor'];
 782                 } elseif (!empty($object['attributedTo'])) {
 783                         $object_actor = $object['attributedTo'];
 784                 } else {
 785                         // Shouldn't happen
 786                         $object_actor = '';
 787                 }
 788
 789                 $signer = [$object_actor];
 790
 791                 if (!empty($child['author'])) {
 792                         $actor = $child['author'];
 793                         $signer[] = $actor;
 794                 } else {
 795                         $actor = $object_actor;
 796                 }
 797
 798                 if (!empty($object['published'])) {
 799                         $published = $object['published'];
 800                 } elseif (!empty($child['published'])) {
 801                         $published = $child['published'];
 802                 } else {
 803                         $published = DateTimeFormat::utcNow();
 804                 }
 805
 806                 $activity = [];
 807                 $activity['@context'] = $object['@context'];
 808                 unset($object['@context']);
 809                 $activity['id'] = $object['id'];
 810                 $activity['to'] = $object['to'] ?? [];
 811                 $activity['cc'] = $object['cc'] ?? [];
 812                 $activity['actor'] = $actor;
 813                 $activity['object'] = $object;
 814                 $activity['published'] = $published;
 815                 $activity['type'] = 'Create';
 816
 817                 $ldactivity = JsonLD::compact($activity);
 818
 819                 if (!empty($relay_actor)) {
 820                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 821                 } elseif (!empty($child['thread-completion'])) {
 822                         $ldactivity['thread-completion'] = $child['thread-completion'];
 823                 } else {
 824                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
 825                 }
 826
 827                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 828                         return '';
 829                 }
 830
 831                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 832
 833                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 834
 835                 return $activity['id'];
 836         }
 837
 838         /**
 839          * Test if incoming relay messages should be accepted
 840          *
 841          * @param array $activity activity array
 842          * @param string $id      object ID
 843          * @return boolean true if message is accepted
 844          */
 845         private static function acceptIncomingMessage(array $activity, string $id)
 846         {
 847                 if (empty($activity['as:object'])) {
 848                         Logger::info('No object field in activity - accepted', ['id' => $id]);
 849                         return true;
 850                 }
 851
 852                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
 853                 if (Item::exists(['uri' => $replyto])) {
 854                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'replyto' => $replyto]);
 855                         return true;
 856                 }
 857
 858                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
 859                 $authorid = Contact::getIdForURL($attributed_to);
 860
 861                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
 862
 863                 $messageTags = [];
 864                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
 865                 if (!empty($tags)) {
 866                         foreach ($tags as $tag) {
 867                                 if ($tag['type'] != 'Hashtag') {
 868                                         continue;
 869                                 }
 870                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
 871                         }
 872                 }
 873
 874                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
 875         }
 876
 877         /**
 878          * perform a "follow" request
 879          *
 880          * @param array $activity
 881          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 882          * @throws \ImagickException
 883          */
 884         public static function followUser($activity)
 885         {
 886                 $uid = User::getIdForURL($activity['object_id']);
 887                 if (empty($uid)) {
 888                         return;
 889                 }
 890
 891                 $owner = User::getOwnerDataById($uid);
 892                 if (empty($owner)) {
 893                         return;
 894                 }
 895
 896                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 897                 if (!empty($cid)) {
 898                         self::switchContact($cid);
 899                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 900                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 901                 } else {
 902                         $contact = [];
 903                 }
 904
 905                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 906                         'author-link' => $activity['actor']];
 907
 908                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 909
 910                 // Ensure that the contact has got the right network type
 911                 self::switchContact($item['author-id']);
 912
 913                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 914                 if ($result === true) {
 915                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 916                 }
 917
 918                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 919                 if (empty($cid)) {
 920                         return;
 921                 }
 922
 923                 if (empty($contact)) {
 924                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 925                 }
 926
 927                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 928         }
 929
 930         /**
 931          * Update the given profile
 932          *
 933          * @param array $activity
 934          * @throws \Exception
 935          */
 936         public static function updatePerson($activity)
 937         {
 938                 if (empty($activity['object_id'])) {
 939                         return;
 940                 }
 941
 942                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 943                 Contact::updateFromProbeByURL($activity['object_id']);
 944         }
 945
 946         /**
 947          * Delete the given profile
 948          *
 949          * @param array $activity
 950          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 951          */
 952         public static function deletePerson($activity)
 953         {
 954                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 955                         Logger::info('Empty object id or actor.');
 956                         return;
 957                 }
 958
 959                 if ($activity['object_id'] != $activity['actor']) {
 960                         Logger::info('Object id does not match actor.');
 961                         return;
 962                 }
 963
 964                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 965                 while ($contact = DBA::fetch($contacts)) {
 966                         Contact::remove($contact['id']);
 967                 }
 968                 DBA::close($contacts);
 969
 970                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 971         }
 972
 973         /**
 974          * Accept a follow request
 975          *
 976          * @param array $activity
 977          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 978          * @throws \ImagickException
 979          */
 980         public static function acceptFollowUser($activity)
 981         {
 982                 $uid = User::getIdForURL($activity['object_actor']);
 983                 if (empty($uid)) {
 984                         return;
 985                 }
 986
 987                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 988                 if (empty($cid)) {
 989                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 990                         return;
 991                 }
 992
 993                 self::switchContact($cid);
 994
 995                 $fields = ['pending' => false];
 996
 997                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 998                 if ($contact['rel'] == Contact::FOLLOWER) {
 999                         $fields['rel'] = Contact::FRIEND;
1000                 }
1001
1002                 $condition = ['id' => $cid];
1003                 DBA::update('contact', $fields, $condition);
1004                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1005         }
1006
1007         /**
1008          * Reject a follow request
1009          *
1010          * @param array $activity
1011          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1012          * @throws \ImagickException
1013          */
1014         public static function rejectFollowUser($activity)
1015         {
1016                 $uid = User::getIdForURL($activity['object_actor']);
1017                 if (empty($uid)) {
1018                         return;
1019                 }
1020
1021                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1022                 if (empty($cid)) {
1023                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1024                         return;
1025                 }
1026
1027                 self::switchContact($cid);
1028
1029                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
1030                         Contact::remove($cid);
1031                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1032                 } else {
1033                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1034                 }
1035         }
1036
1037         /**
1038          * Undo activity like "like" or "dislike"
1039          *
1040          * @param array $activity
1041          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1042          * @throws \ImagickException
1043          */
1044         public static function undoActivity($activity)
1045         {
1046                 if (empty($activity['object_id'])) {
1047                         return;
1048                 }
1049
1050                 if (empty($activity['object_actor'])) {
1051                         return;
1052                 }
1053
1054                 $author_id = Contact::getIdForURL($activity['object_actor']);
1055                 if (empty($author_id)) {
1056                         return;
1057                 }
1058
1059                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1060         }
1061
1062         /**
1063          * Activity to remove a follower
1064          *
1065          * @param array $activity
1066          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1067          * @throws \ImagickException
1068          */
1069         public static function undoFollowUser($activity)
1070         {
1071                 $uid = User::getIdForURL($activity['object_object']);
1072                 if (empty($uid)) {
1073                         return;
1074                 }
1075
1076                 $owner = User::getOwnerDataById($uid);
1077                 if (empty($owner)) {
1078                         return;
1079                 }
1080
1081                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1082                 if (empty($cid)) {
1083                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1084                         return;
1085                 }
1086
1087                 self::switchContact($cid);
1088
1089                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1090                 if (!DBA::isResult($contact)) {
1091                         return;
1092                 }
1093
1094                 Contact::removeFollower($owner, $contact);
1095                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1096         }
1097
1098         /**
1099          * Switches a contact to AP if needed
1100          *
1101          * @param integer $cid Contact ID
1102          * @throws \Exception
1103          */
1104         private static function switchContact($cid)
1105         {
1106                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1107                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1108                         return;
1109                 }
1110
1111                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1112                 Contact::updateFromProbe($cid);
1113         }
1114
1115         /**
1116          * Collects implicit mentions like:
1117          * - the author of the parent item
1118          * - all the mentioned conversants in the parent item
1119          *
1120          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1121          * @return array
1122          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1123          */
1124         private static function getImplicitMentionList(array $parent)
1125         {
1126                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1127
1128                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1129
1130                 $implicit_mentions = [];
1131                 if (empty($parent_author['url'])) {
1132                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1133                 } else {
1134                         $implicit_mentions[] = $parent_author['url'];
1135                         $implicit_mentions[] = $parent_author['nurl'];
1136                         $implicit_mentions[] = $parent_author['alias'];
1137                 }
1138
1139                 if (!empty($parent['alias'])) {
1140                         $implicit_mentions[] = $parent['alias'];
1141                 }
1142
1143                 foreach ($parent_terms as $term) {
1144                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1145                         if (!empty($contact['url'])) {
1146                                 $implicit_mentions[] = $contact['url'];
1147                                 $implicit_mentions[] = $contact['nurl'];
1148                                 $implicit_mentions[] = $contact['alias'];
1149                         }
1150                 }
1151
1152                 return $implicit_mentions;
1153         }
1154
1155         /**
1156          * Strips from the body prepended implicit mentions
1157          *
1158          * @param string $body
1159          * @param array $parent
1160          * @return string
1161          */
1162         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1163         {
1164                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1165                         return $body;
1166                 }
1167
1168                 $potential_mentions = self::getImplicitMentionList($parent);
1169
1170                 $kept_mentions = [];
1171
1172                 // Extract one prepended mention at a time from the body
1173                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1174                         if (!in_array($matches[2], $potential_mentions)) {
1175                                 $kept_mentions[] = $matches[1];
1176                         }
1177
1178                         $body = $matches[3];
1179                 }
1180
1181                 // Re-appending the kept mentions to the body after extraction
1182                 $kept_mentions[] = $body;
1183
1184                 return implode('', $kept_mentions);
1185         }
1186 }