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 $item;
 136                 }
 137
 138                 foreach ($activity['attachments'] as $attach) {
 139                         switch ($attach['type']) {
 140                                 case 'link':
 141                                         $data = [
 142                                                 'url'      => $attach['url'],
 143                                                 'type'     => $attach['type'],
 144                                                 'title'    => $attach['title'] ?? '',
 145                                                 'text'     => $attach['desc']  ?? '',
 146                                                 'image'    => $attach['image'] ?? '',
 147                                                 'images'   => [],
 148                                                 'keywords' => [],
 149                                         ];
 150                                         $item['body'] = PageInfo::appendDataToBody($item['body'], $data);
 151                                         break;
 152                                 default:
 153                                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 154
 155                                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 156                                         if ($filetype == 'image') {
 157                                                 if (!empty($activity['source'])) {
 158                                                         foreach ([0, 1, 2] as $size) {
 159                                                                 if (preg_match('#/photo/.*-' . $size . '\.#ism', $attach['url']) &&
 160                                                                         strpos(preg_replace('#(/photo/.*)-[012]\.#ism', '$1-' . $size . '.', $activity['source']), $attach['url'])) {
 161                                                                         continue 3;
 162                                                                 }
 163                                                         }
 164                                                         if (strpos($activity['source'], $attach['url'])) {
 165                                                                 continue 2;
 166                                                         }
 167                                                 }
 168
 169                                                 $item['body'] .= "\n";
 170
 171                                                 // image is the preview/thumbnail URL
 172                                                 if (!empty($attach['image'])) {
 173                                                         $item['body'] .= '[url=' . $attach['url'] . ']';
 174                                                         $attach['url'] = $attach['image'];
 175                                                 }
 176
 177                                                 if (empty($attach['name'])) {
 178                                                         $item['body'] .= '[img]' . $attach['url'] . '[/img]';
 179                                                 } else {
 180                                                         $item['body'] .= '[img=' . $attach['url'] . ']' . $attach['name'] . '[/img]';
 181                                                 }
 182
 183                                                 if (!empty($attach['image'])) {
 184                                                         $item['body'] .= '[/url]';
 185                                                 }
 186                                         } elseif ($filetype == 'audio') {
 187                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 188                                                         continue 2;
 189                                                 }
 190
 191                                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 192                                         } elseif ($filetype == 'video') {
 193                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 194                                                         continue 2;
 195                                                 }
 196
 197                                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 198                                         }
 199                         }
 200                 }
 201
 202                 return $item;
 203         }
 204
 205         /**
 206          * Updates a message
 207          *
 208          * @param array $activity Activity array
 209          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 210          */
 211         public static function updateItem($activity)
 212         {
 213                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 214                 if (!DBA::isResult($item)) {
 215                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 216                         $item = self::createItem($activity);
 217                         self::postItem($activity, $item);
 218                         return;
 219                 }
 220
 221                 $item['changed'] = DateTimeFormat::utcNow();
 222                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 223
 224                 $item = self::processContent($activity, $item);
 225
 226                 $item = self::constructAttachList($activity, $item);
 227
 228                 if (empty($item)) {
 229                         return;
 230                 }
 231
 232                 Item::update($item, ['uri' => $activity['id']]);
 233         }
 234
 235         /**
 236          * Prepares data for a message
 237          *
 238          * @param array $activity Activity array
 239          * @return array Internal item
 240          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 241          * @throws \ImagickException
 242          */
 243         public static function createItem($activity)
 244         {
 245                 $item = [];
 246                 $item['verb'] = Activity::POST;
 247                 $item['thr-parent'] = $activity['reply-to-id'];
 248
 249                 if ($activity['reply-to-id'] == $activity['id']) {
 250                         $item['gravity'] = GRAVITY_PARENT;
 251                         $item['object-type'] = Activity\ObjectType::NOTE;
 252                 } else {
 253                         $item['gravity'] = GRAVITY_COMMENT;
 254                         $item['object-type'] = Activity\ObjectType::COMMENT;
 255                 }
 256
 257                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 258                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 259                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 260                 }
 261
 262                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 263
 264                 /// @todo What to do with $activity['context']?
 265                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 266                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 267                         return [];
 268                 }
 269
 270                 $item['network'] = Protocol::ACTIVITYPUB;
 271                 $item['author-link'] = $activity['author'];
 272                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 273                 $item['owner-link'] = $activity['actor'];
 274                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 275
 276                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 277                         $item['private'] = Item::UNLISTED;
 278                 } elseif (in_array(0, $activity['receiver'])) {
 279                         $item['private'] = Item::PUBLIC;
 280                 } else {
 281                         $item['private'] = Item::PRIVATE;
 282                 }
 283
 284                 if (!empty($activity['raw'])) {
 285                         $item['source'] = $activity['raw'];
 286                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 287                         $item['conversation-href'] = $activity['context'] ?? '';
 288                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 289
 290                         if (isset($activity['push'])) {
 291                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 292                         }
 293                 }
 294
 295                 $item['isForum'] = false;
 296
 297                 if (!empty($activity['thread-completion'])) {
 298                         if ($activity['thread-completion'] != $item['owner-id']) {
 299                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 300                                 $item['causer-link'] = $actor['url'];
 301                                 $item['causer-id'] = $activity['thread-completion'];
 302                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 303                         } else {
 304                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 305                                 $item['causer-link'] = $item['owner-link'];
 306                                 $item['causer-id'] = $item['owner-id'];
 307                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 308                         }
 309
 310                         $item['owner-link'] = $item['author-link'];
 311                         $item['owner-id'] = $item['author-id'];
 312                 } else {
 313                         $actor = APContact::getByURL($item['owner-link'], false);
 314                         $item['isForum'] = ($actor['type'] == 'Group');
 315                 }
 316
 317                 $item['uri'] = $activity['id'];
 318
 319                 $item['created'] = DateTimeFormat::utc($activity['published']);
 320                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 321                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 322                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 323
 324                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 325
 326                 $item = self::processContent($activity, $item);
 327                 if (empty($item)) {
 328                         Logger::info('Message was not processed');
 329                         return [];
 330                 }
 331
 332                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 333
 334                 $item = self::constructAttachList($activity, $item);
 335
 336                 return $item;
 337         }
 338
 339         /**
 340          * Delete items
 341          *
 342          * @param array $activity
 343          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 344          * @throws \ImagickException
 345          */
 346         public static function deleteItem($activity)
 347         {
 348                 $owner = Contact::getIdForURL($activity['actor']);
 349
 350                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 351                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 352         }
 353
 354         /**
 355          * Prepare the item array for an activity
 356          *
 357          * @param array $activity Activity array
 358          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 359          * @throws \ImagickException
 360          */
 361         public static function addTag($activity)
 362         {
 363                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 364                         return;
 365                 }
 366
 367                 foreach ($activity['receiver'] as $receiver) {
 368                         $item = Item::selectFirst(['id', 'uri-id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 369                         if (!DBA::isResult($item)) {
 370                                 // We don't fetch missing content for this purpose
 371                                 continue;
 372                         }
 373
 374                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 375                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 376                                 continue;
 377                         }
 378
 379                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 380                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 381                 }
 382         }
 383
 384         /**
 385          * Prepare the item array for an activity
 386          *
 387          * @param array  $activity Activity array
 388          * @param string $verb     Activity verb
 389          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 390          * @throws \ImagickException
 391          */
 392         public static function createActivity($activity, $verb)
 393         {
 394                 $item = self::createItem($activity);
 395                 $item['verb'] = $verb;
 396                 $item['thr-parent'] = $activity['object_id'];
 397                 $item['gravity'] = GRAVITY_ACTIVITY;
 398                 $item['object-type'] = Activity\ObjectType::NOTE;
 399
 400                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 401
 402                 self::postItem($activity, $item);
 403         }
 404
 405         /**
 406          * Create an event
 407          *
 408          * @param array $activity Activity array
 409          * @param array $item
 410          * @throws \Exception
 411          */
 412         public static function createEvent($activity, $item)
 413         {
 414                 $event['summary']  = HTML::toBBCode($activity['name']);
 415                 $event['desc']     = HTML::toBBCode($activity['content']);
 416                 $event['start']    = $activity['start-time'];
 417                 $event['finish']   = $activity['end-time'];
 418                 $event['nofinish'] = empty($event['finish']);
 419                 $event['location'] = $activity['location'];
 420                 $event['adjust']   = true;
 421                 $event['cid']      = $item['contact-id'];
 422                 $event['uid']      = $item['uid'];
 423                 $event['uri']      = $item['uri'];
 424                 $event['edited']   = $item['edited'];
 425                 $event['private']  = $item['private'];
 426                 $event['guid']     = $item['guid'];
 427                 $event['plink']    = $item['plink'];
 428
 429                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 430                 $ev = DBA::selectFirst('event', ['id'], $condition);
 431                 if (DBA::isResult($ev)) {
 432                         $event['id'] = $ev['id'];
 433                 }
 434
 435                 $event_id = Event::store($event);
 436                 Logger::info('Event was stored', ['id' => $event_id]);
 437         }
 438
 439         /**
 440          * Process the content
 441          *
 442          * @param array $activity Activity array
 443          * @param array $item
 444          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 445          * @throws \Exception
 446          */
 447         private static function processContent($activity, $item)
 448         {
 449                 $item['title'] = HTML::toBBCode($activity['name']);
 450
 451                 $content = HTML::toBBCode($activity['content']);
 452
 453                 if (!empty($activity['emojis'])) {
 454                         $content = self::replaceEmojis($content, $activity['emojis']);
 455                 }
 456
 457                 $content = self::convertMentions($content);
 458
 459                 if (!empty($activity['source'])) {
 460                         $item['body'] = $activity['source'];
 461                         $item['raw-body'] = $content;
 462                 } else {
 463                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 464                                 $item_private = !in_array(0, $activity['item_receiver']);
 465                                 $parent = Item::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 466                                 if (!DBA::isResult($parent)) {
 467                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 468                                         return false;
 469                                 }
 470                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 471                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 472                                         return false;
 473                                 }
 474
 475                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 476                         }
 477                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 478                         $item['raw-body'] = $item['body'] = $content;
 479                 }
 480
 481                 self::storeFromBody($item);
 482                 self::storeTags($item['uri-id'], $activity['tags']);
 483
 484                 $item['location'] = $activity['location'];
 485
 486                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 487                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 488                 }
 489
 490                 $item['app'] = $activity['generator'];
 491
 492                 return $item;
 493         }
 494
 495         /**
 496          * Store hashtags and mentions
 497          *
 498          * @param array $item
 499          */
 500         private static function storeFromBody(array $item)
 501         {
 502                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 503                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 504
 505                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 506         }
 507
 508         /**
 509          * Generate a GUID out of an URL
 510          *
 511          * @param string $url message URL
 512          * @return string with GUID
 513          */
 514         private static function getGUIDByURL(string $url)
 515         {
 516                 $parsed = parse_url($url);
 517
 518                 $host_hash = hash('crc32', $parsed['host']);
 519
 520                 unset($parsed["scheme"]);
 521                 unset($parsed["host"]);
 522
 523                 $path = implode("/", $parsed);
 524
 525                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 526         }
 527
 528         /**
 529          * Creates an item post
 530          *
 531          * @param array $activity Activity data
 532          * @param array $item     item array
 533          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 534          * @throws \ImagickException
 535          */
 536         public static function postItem(array $activity, array $item)
 537         {
 538                 if (empty($item)) {
 539                         return;
 540                 }
 541
 542                 $stored = false;
 543                 ksort($activity['receiver']);
 544
 545                 foreach ($activity['receiver'] as $receiver) {
 546                         if ($receiver == -1) {
 547                                 continue;
 548                         }
 549
 550                         $item['uid'] = $receiver;
 551
 552                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 553                         switch($type) {
 554                                 case Receiver::TARGET_TO:
 555                                         $item['post-type'] = Item::PT_TO;
 556                                         break;
 557                                 case Receiver::TARGET_CC:
 558                                         $item['post-type'] = Item::PT_CC;
 559                                         break;
 560                                 case Receiver::TARGET_BTO:
 561                                         $item['post-type'] = Item::PT_BTO;
 562                                         break;
 563                                 case Receiver::TARGET_BCC:
 564                                         $item['post-type'] = Item::PT_BCC;
 565                                         break;
 566                                 case Receiver::TARGET_FOLLOWER:
 567                                         $item['post-type'] = Item::PT_FOLLOWER;
 568                                         break;
 569                                 case Receiver::TARGET_ANSWER:
 570                                         $item['post-type'] = Item::PT_COMMENT;
 571                                         break;
 572                                 case Receiver::TARGET_GLOBAL:
 573                                         $item['post-type'] = Item::PT_GLOBAL;
 574                                         break;
 575                                 default:
 576                                         $item['post-type'] = Item::PT_ARTICLE;
 577                         }
 578
 579                         if (!empty($activity['from-relay'])) {
 580                                 $item['post-type'] = Item::PT_RELAY;
 581                         } elseif (!empty($activity['thread-completion'])) {
 582                                 $item['post-type'] = Item::PT_FETCHED;
 583                         }
 584
 585                         if ($item['isForum'] ?? false) {
 586                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 587                         } else {
 588                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 589                         }
 590
 591                         if (($receiver != 0) && empty($item['contact-id'])) {
 592                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 593                         }
 594
 595                         if (!empty($activity['directmessage'])) {
 596                                 self::postMail($activity, $item);
 597                                 continue;
 598                         }
 599
 600                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 601                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 602
 603                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 604                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 605                                 }
 606
 607                                 if ($skip) {
 608                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 609                                         continue;
 610                                 }
 611
 612                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 613                         }
 614
 615                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 616                                 self::createEvent($activity, $item);
 617                         }
 618
 619                         $item_id = Item::insert($item);
 620                         if ($item_id) {
 621                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 622                         } else {
 623                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 624                         }
 625
 626                         if ($item['uid'] == 0) {
 627                                 $stored = $item_id;
 628                         }
 629                 }
 630
 631                 // Store send a follow request for every reshare - but only when the item had been stored
 632                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 633                         $author = APContact::getByURL($item['owner-link'], false);
 634                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 635                         if ($author['type'] != 'Group') {
 636                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 637                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 638                         }
 639                 }
 640         }
 641
 642         /**
 643          * Store tags and mentions into the tag table
 644          *
 645          * @param integer $uriid
 646          * @param array $tags
 647          */
 648         private static function storeTags(int $uriid, array $tags = null)
 649         {
 650                 foreach ($tags as $tag) {
 651                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 652                                 continue;
 653                         }
 654
 655                         $hash = substr($tag['name'], 0, 1);
 656
 657                         if ($tag['type'] == 'Mention') {
 658                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 659                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 660                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 661                                         $tag['name'] = substr($tag['name'], 1);
 662                                 }
 663                                 $type = Tag::IMPLICIT_MENTION;
 664
 665                                 if (!empty($tag['href'])) {
 666                                         $apcontact = APContact::getByURL($tag['href']);
 667                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 668                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 669                                         }
 670                                 }
 671                         } elseif ($tag['type'] == 'Hashtag') {
 672                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 673                                         $tag['name'] = substr($tag['name'], 1);
 674                                 }
 675                                 $type = Tag::HASHTAG;
 676                         }
 677
 678                         if (empty($tag['name'])) {
 679                                 continue;
 680                         }
 681
 682                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 683                 }
 684         }
 685
 686         /**
 687          * Creates an mail post
 688          *
 689          * @param array $activity Activity data
 690          * @param array $item     item array
 691          * @return int|bool New mail table row id or false on error
 692          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 693          */
 694         private static function postMail($activity, $item)
 695         {
 696                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 697                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 698                         return false;
 699                 }
 700
 701                 Logger::info('Direct Message', $item);
 702
 703                 $msg = [];
 704                 $msg['uid'] = $item['uid'];
 705
 706                 $msg['contact-id'] = $item['contact-id'];
 707
 708                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 709                 $msg['from-name'] = $contact['name'];
 710                 $msg['from-url'] = $contact['url'];
 711                 $msg['from-photo'] = $contact['photo'];
 712
 713                 $msg['uri'] = $item['uri'];
 714                 $msg['created'] = $item['created'];
 715
 716                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 717                 if (DBA::isResult($parent)) {
 718                         $msg['parent-uri'] = $parent['parent-uri'];
 719                         $msg['title'] = $parent['title'];
 720                 } else {
 721                         $msg['parent-uri'] = $item['thr-parent'];
 722
 723                         if (!empty($item['title'])) {
 724                                 $msg['title'] = $item['title'];
 725                         } elseif (!empty($item['content-warning'])) {
 726                                 $msg['title'] = $item['content-warning'];
 727                         } else {
 728                                 // Trying to generate a title out of the body
 729                                 $title = $item['body'];
 730
 731                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 732                                         $title = $matches[3];
 733                                 }
 734
 735                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, BBCode::API, true), 0));
 736
 737                                 if (strlen($title) > 20) {
 738                                         $title = substr($title, 0, 20) . '...';
 739                                 }
 740
 741                                 $msg['title'] = $title;
 742                         }
 743                 }
 744                 $msg['body'] = $item['body'];
 745
 746                 return Mail::insert($msg);
 747         }
 748
 749         /**
 750          * Fetches missing posts
 751          *
 752          * @param string $url         message URL
 753          * @param array  $child       activity array with the child of this message
 754          * @param string $relay_actor Relay actor
 755          * @return string fetched message URL
 756          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 757          */
 758         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
 759         {
 760                 if (!empty($child['receiver'])) {
 761                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 762                 } else {
 763                         $uid = 0;
 764                 }
 765
 766                 $object = ActivityPub::fetchContent($url, $uid);
 767                 if (empty($object)) {
 768                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 769                         return '';
 770                 }
 771
 772                 if (empty($object['id'])) {
 773                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 774                         return '';
 775                 }
 776
 777                 if (!empty($object['actor'])) {
 778                         $object_actor = $object['actor'];
 779                 } elseif (!empty($object['attributedTo'])) {
 780                         $object_actor = $object['attributedTo'];
 781                         if (is_array($object_actor)) {
 782                                 $compacted = JsonLD::compact($object);
 783                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
 784                         }
 785                 } else {
 786                         // Shouldn't happen
 787                         $object_actor = '';
 788                 }
 789
 790                 $signer = [$object_actor];
 791
 792                 if (!empty($child['author'])) {
 793                         $actor = $child['author'];
 794                         $signer[] = $actor;
 795                 } else {
 796                         $actor = $object_actor;
 797                 }
 798
 799                 if (!empty($object['published'])) {
 800                         $published = $object['published'];
 801                 } elseif (!empty($child['published'])) {
 802                         $published = $child['published'];
 803                 } else {
 804                         $published = DateTimeFormat::utcNow();
 805                 }
 806
 807                 $activity = [];
 808                 $activity['@context'] = $object['@context'];
 809                 unset($object['@context']);
 810                 $activity['id'] = $object['id'];
 811                 $activity['to'] = $object['to'] ?? [];
 812                 $activity['cc'] = $object['cc'] ?? [];
 813                 $activity['actor'] = $actor;
 814                 $activity['object'] = $object;
 815                 $activity['published'] = $published;
 816                 $activity['type'] = 'Create';
 817
 818                 $ldactivity = JsonLD::compact($activity);
 819
 820                 if (!empty($relay_actor)) {
 821                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 822                 } elseif (!empty($child['thread-completion'])) {
 823                         $ldactivity['thread-completion'] = $child['thread-completion'];
 824                 } else {
 825                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
 826                 }
 827
 828                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 829                         return '';
 830                 }
 831
 832                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 833
 834                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 835
 836                 return $activity['id'];
 837         }
 838
 839         /**
 840          * Test if incoming relay messages should be accepted
 841          *
 842          * @param array $activity activity array
 843          * @param string $id      object ID
 844          * @return boolean true if message is accepted
 845          */
 846         private static function acceptIncomingMessage(array $activity, string $id)
 847         {
 848                 if (empty($activity['as:object'])) {
 849                         Logger::info('No object field in activity - accepted', ['id' => $id]);
 850                         return true;
 851                 }
 852
 853                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
 854                 if (Item::exists(['uri' => $replyto])) {
 855                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'replyto' => $replyto]);
 856                         return true;
 857                 }
 858
 859                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
 860                 $authorid = Contact::getIdForURL($attributed_to);
 861
 862                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
 863
 864                 $messageTags = [];
 865                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
 866                 if (!empty($tags)) {
 867                         foreach ($tags as $tag) {
 868                                 if ($tag['type'] != 'Hashtag') {
 869                                         continue;
 870                                 }
 871                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
 872                         }
 873                 }
 874
 875                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
 876         }
 877
 878         /**
 879          * perform a "follow" request
 880          *
 881          * @param array $activity
 882          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 883          * @throws \ImagickException
 884          */
 885         public static function followUser($activity)
 886         {
 887                 $uid = User::getIdForURL($activity['object_id']);
 888                 if (empty($uid)) {
 889                         return;
 890                 }
 891
 892                 $owner = User::getOwnerDataById($uid);
 893                 if (empty($owner)) {
 894                         return;
 895                 }
 896
 897                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 898                 if (!empty($cid)) {
 899                         self::switchContact($cid);
 900                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 901                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 902                 } else {
 903                         $contact = [];
 904                 }
 905
 906                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 907                         'author-link' => $activity['actor']];
 908
 909                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 910
 911                 // Ensure that the contact has got the right network type
 912                 self::switchContact($item['author-id']);
 913
 914                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 915                 if ($result === true) {
 916                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 917                 }
 918
 919                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 920                 if (empty($cid)) {
 921                         return;
 922                 }
 923
 924                 if (empty($contact)) {
 925                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 926                 }
 927
 928                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 929         }
 930
 931         /**
 932          * Update the given profile
 933          *
 934          * @param array $activity
 935          * @throws \Exception
 936          */
 937         public static function updatePerson($activity)
 938         {
 939                 if (empty($activity['object_id'])) {
 940                         return;
 941                 }
 942
 943                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 944                 Contact::updateFromProbeByURL($activity['object_id']);
 945         }
 946
 947         /**
 948          * Delete the given profile
 949          *
 950          * @param array $activity
 951          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 952          */
 953         public static function deletePerson($activity)
 954         {
 955                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 956                         Logger::info('Empty object id or actor.');
 957                         return;
 958                 }
 959
 960                 if ($activity['object_id'] != $activity['actor']) {
 961                         Logger::info('Object id does not match actor.');
 962                         return;
 963                 }
 964
 965                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 966                 while ($contact = DBA::fetch($contacts)) {
 967                         Contact::remove($contact['id']);
 968                 }
 969                 DBA::close($contacts);
 970
 971                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 972         }
 973
 974         /**
 975          * Accept a follow request
 976          *
 977          * @param array $activity
 978          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 979          * @throws \ImagickException
 980          */
 981         public static function acceptFollowUser($activity)
 982         {
 983                 $uid = User::getIdForURL($activity['object_actor']);
 984                 if (empty($uid)) {
 985                         return;
 986                 }
 987
 988                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 989                 if (empty($cid)) {
 990                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 991                         return;
 992                 }
 993
 994                 self::switchContact($cid);
 995
 996                 $fields = ['pending' => false];
 997
 998                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 999                 if ($contact['rel'] == Contact::FOLLOWER) {
1000                         $fields['rel'] = Contact::FRIEND;
1001                 }
1002
1003                 $condition = ['id' => $cid];
1004                 DBA::update('contact', $fields, $condition);
1005                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1006         }
1007
1008         /**
1009          * Reject a follow request
1010          *
1011          * @param array $activity
1012          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1013          * @throws \ImagickException
1014          */
1015         public static function rejectFollowUser($activity)
1016         {
1017                 $uid = User::getIdForURL($activity['object_actor']);
1018                 if (empty($uid)) {
1019                         return;
1020                 }
1021
1022                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1023                 if (empty($cid)) {
1024                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1025                         return;
1026                 }
1027
1028                 self::switchContact($cid);
1029
1030                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
1031                         Contact::remove($cid);
1032                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1033                 } else {
1034                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1035                 }
1036         }
1037
1038         /**
1039          * Undo activity like "like" or "dislike"
1040          *
1041          * @param array $activity
1042          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1043          * @throws \ImagickException
1044          */
1045         public static function undoActivity($activity)
1046         {
1047                 if (empty($activity['object_id'])) {
1048                         return;
1049                 }
1050
1051                 if (empty($activity['object_actor'])) {
1052                         return;
1053                 }
1054
1055                 $author_id = Contact::getIdForURL($activity['object_actor']);
1056                 if (empty($author_id)) {
1057                         return;
1058                 }
1059
1060                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1061         }
1062
1063         /**
1064          * Activity to remove a follower
1065          *
1066          * @param array $activity
1067          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1068          * @throws \ImagickException
1069          */
1070         public static function undoFollowUser($activity)
1071         {
1072                 $uid = User::getIdForURL($activity['object_object']);
1073                 if (empty($uid)) {
1074                         return;
1075                 }
1076
1077                 $owner = User::getOwnerDataById($uid);
1078                 if (empty($owner)) {
1079                         return;
1080                 }
1081
1082                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1083                 if (empty($cid)) {
1084                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1085                         return;
1086                 }
1087
1088                 self::switchContact($cid);
1089
1090                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1091                 if (!DBA::isResult($contact)) {
1092                         return;
1093                 }
1094
1095                 Contact::removeFollower($owner, $contact);
1096                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1097         }
1098
1099         /**
1100          * Switches a contact to AP if needed
1101          *
1102          * @param integer $cid Contact ID
1103          * @throws \Exception
1104          */
1105         private static function switchContact($cid)
1106         {
1107                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1108                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1109                         return;
1110                 }
1111
1112                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1113                 Contact::updateFromProbe($cid);
1114         }
1115
1116         /**
1117          * Collects implicit mentions like:
1118          * - the author of the parent item
1119          * - all the mentioned conversants in the parent item
1120          *
1121          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1122          * @return array
1123          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1124          */
1125         private static function getImplicitMentionList(array $parent)
1126         {
1127                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1128
1129                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1130
1131                 $implicit_mentions = [];
1132                 if (empty($parent_author['url'])) {
1133                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1134                 } else {
1135                         $implicit_mentions[] = $parent_author['url'];
1136                         $implicit_mentions[] = $parent_author['nurl'];
1137                         $implicit_mentions[] = $parent_author['alias'];
1138                 }
1139
1140                 if (!empty($parent['alias'])) {
1141                         $implicit_mentions[] = $parent['alias'];
1142                 }
1143
1144                 foreach ($parent_terms as $term) {
1145                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1146                         if (!empty($contact['url'])) {
1147                                 $implicit_mentions[] = $contact['url'];
1148                                 $implicit_mentions[] = $contact['nurl'];
1149                                 $implicit_mentions[] = $contact['alias'];
1150                         }
1151                 }
1152
1153                 return $implicit_mentions;
1154         }
1155
1156         /**
1157          * Strips from the body prepended implicit mentions
1158          *
1159          * @param string $body
1160          * @param array $parent
1161          * @return string
1162          */
1163         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1164         {
1165                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1166                         return $body;
1167                 }
1168
1169                 $potential_mentions = self::getImplicitMentionList($parent);
1170
1171                 $kept_mentions = [];
1172
1173                 // Extract one prepended mention at a time from the body
1174                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1175                         if (!in_array($matches[2], $potential_mentions)) {
1176                                 $kept_mentions[] = $matches[1];
1177                         }
1178
1179                         $body = $matches[3];
1180                 }
1181
1182                 // Re-appending the kept mentions to the body after extraction
1183                 $kept_mentions[] = $body;
1184
1185                 return implode('', $kept_mentions);
1186         }
1187 }