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                 $body = strtr($body,
  79                         array_combine(
  80                                 array_column($emojis, 'name'),
  81                                 array_map(function ($emoji) {
  82                                         return '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
  83                                 }, $emojis)
  84                         )
  85                 );
  86
  87                 return $body;
  88         }
  89
  90         /**
  91          * Store attached media files in the post-media table
  92          *
  93          * @param int $uriid
  94          * @param array $attachment
  95          * @return void
  96          */
  97         private static function storeAttachmentAsMedia(int $uriid, array $attachment)
  98         {
  99                 if (empty($attachment['url'])) {
 100                         return;
 101                 }
 102
 103                 $data = ['uri-id' => $uriid];
 104
 105                 $filetype = strtolower(substr($attachment['mediaType'], 0, strpos($attachment['mediaType'], '/')));
 106                 if ($filetype == 'image') {
 107                         $data['type'] = Post\Media::IMAGE;
 108                 } elseif ($filetype == 'video') {
 109                         $data['type'] = Post\Media::VIDEO;
 110                 } elseif ($filetype == 'audio') {
 111                         $data['type'] = Post\Media::AUDIO;
 112                 } elseif (in_array($attachment['mediaType'], ['application/x-bittorrent', 'application/x-bittorrent;x-scheme-handler/magnet'])) {
 113                         $data['type'] = Post\Media::TORRENT;
 114                 } else {
 115                         Logger::info('Unknown type', ['attachment' => $attachment]);
 116                         return;
 117                 }
 118
 119                 $data['url'] = $attachment['url'];
 120                 $data['mimetype'] = $attachment['mediaType'];
 121                 $data['height'] = $attachment['height'] ?? null;
 122                 $data['size'] = $attachment['size'] ?? null;
 123                 $data['preview'] = $attachment['image'] ?? null;
 124                 $data['description'] = $attachment['name'] ?? null;
 125
 126                 Post\Media::insert($data);
 127         }
 128
 129         /**
 130          * Add attachment data to the item array
 131          *
 132          * @param array   $activity
 133          * @param array   $item
 134          *
 135          * @return array array
 136          */
 137         private static function constructAttachList($activity, $item)
 138         {
 139                 if (empty($activity['attachments'])) {
 140                         return $item;
 141                 }
 142
 143                 foreach ($activity['attachments'] as $attach) {
 144                         switch ($attach['type']) {
 145                                 case 'link':
 146                                         $data = [
 147                                                 'url'      => $attach['url'],
 148                                                 'type'     => $attach['type'],
 149                                                 'title'    => $attach['title'] ?? '',
 150                                                 'text'     => $attach['desc']  ?? '',
 151                                                 'image'    => $attach['image'] ?? '',
 152                                                 'images'   => [],
 153                                                 'keywords' => [],
 154                                         ];
 155                                         $item['body'] = PageInfo::appendDataToBody($item['body'], $data);
 156                                         break;
 157                                 default:
 158                                         self::storeAttachmentAsMedia($item['uri-id'], $attach);
 159
 160                                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 161                                         if ($filetype == 'image') {
 162                                                 if (!empty($activity['source'])) {
 163                                                         foreach ([0, 1, 2] as $size) {
 164                                                                 if (preg_match('#/photo/.*-' . $size . '\.#ism', $attach['url']) &&
 165                                                                         strpos(preg_replace('#(/photo/.*)-[012]\.#ism', '$1-' . $size . '.', $activity['source']), $attach['url'])) {
 166                                                                         continue 3;
 167                                                                 }
 168                                                         }
 169                                                         if (strpos($activity['source'], $attach['url'])) {
 170                                                                 continue 2;
 171                                                         }
 172                                                 }
 173
 174                                                 $item['body'] .= "\n";
 175
 176                                                 // image is the preview/thumbnail URL
 177                                                 if (!empty($attach['image'])) {
 178                                                         $item['body'] .= '[url=' . $attach['url'] . ']';
 179                                                         $attach['url'] = $attach['image'];
 180                                                 }
 181
 182                                                 if (empty($attach['name'])) {
 183                                                         $item['body'] .= '[img]' . $attach['url'] . '[/img]';
 184                                                 } else {
 185                                                         $item['body'] .= '[img=' . $attach['url'] . ']' . $attach['name'] . '[/img]';
 186                                                 }
 187
 188                                                 if (!empty($attach['image'])) {
 189                                                         $item['body'] .= '[/url]';
 190                                                 }
 191                                         } elseif ($filetype == 'audio') {
 192                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 193                                                         continue 2;
 194                                                 }
 195
 196                                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 197                                         } elseif ($filetype == 'video') {
 198                                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 199                                                         continue 2;
 200                                                 }
 201
 202                                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 203                                         }
 204                         }
 205                 }
 206
 207                 return $item;
 208         }
 209
 210         /**
 211          * Updates a message
 212          *
 213          * @param array $activity Activity array
 214          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 215          */
 216         public static function updateItem($activity)
 217         {
 218                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 219                 if (!DBA::isResult($item)) {
 220                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 221                         $item = self::createItem($activity);
 222                         self::postItem($activity, $item);
 223                         return;
 224                 }
 225
 226                 $item['changed'] = DateTimeFormat::utcNow();
 227                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 228
 229                 $item = self::processContent($activity, $item);
 230
 231                 $item = self::constructAttachList($activity, $item);
 232
 233                 if (empty($item)) {
 234                         return;
 235                 }
 236
 237                 Item::update($item, ['uri' => $activity['id']]);
 238         }
 239
 240         /**
 241          * Prepares data for a message
 242          *
 243          * @param array $activity Activity array
 244          * @return array Internal item
 245          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 246          * @throws \ImagickException
 247          */
 248         public static function createItem($activity)
 249         {
 250                 $item = [];
 251                 $item['verb'] = Activity::POST;
 252                 $item['thr-parent'] = $activity['reply-to-id'];
 253
 254                 if ($activity['reply-to-id'] == $activity['id']) {
 255                         $item['gravity'] = GRAVITY_PARENT;
 256                         $item['object-type'] = Activity\ObjectType::NOTE;
 257                 } else {
 258                         $item['gravity'] = GRAVITY_COMMENT;
 259                         $item['object-type'] = Activity\ObjectType::COMMENT;
 260                 }
 261
 262                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 263                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 264                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 265                 }
 266
 267                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 268
 269                 /// @todo What to do with $activity['context']?
 270                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 271                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 272                         return [];
 273                 }
 274
 275                 $item['network'] = Protocol::ACTIVITYPUB;
 276                 $item['author-link'] = $activity['author'];
 277                 $item['author-id'] = Contact::getIdForURL($activity['author']);
 278                 $item['owner-link'] = $activity['actor'];
 279                 $item['owner-id'] = Contact::getIdForURL($activity['actor']);
 280
 281                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 282                         $item['private'] = Item::UNLISTED;
 283                 } elseif (in_array(0, $activity['receiver'])) {
 284                         $item['private'] = Item::PUBLIC;
 285                 } else {
 286                         $item['private'] = Item::PRIVATE;
 287                 }
 288
 289                 if (!empty($activity['raw'])) {
 290                         $item['source'] = $activity['raw'];
 291                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 292                         $item['conversation-href'] = $activity['context'] ?? '';
 293                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 294
 295                         if (isset($activity['push'])) {
 296                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 297                         }
 298                 }
 299
 300                 $item['isForum'] = false;
 301
 302                 if (!empty($activity['thread-completion'])) {
 303                         if ($activity['thread-completion'] != $item['owner-id']) {
 304                                 $actor = Contact::getById($activity['thread-completion'], ['url']);
 305                                 $item['causer-link'] = $actor['url'];
 306                                 $item['causer-id'] = $activity['thread-completion'];
 307                                 Logger::info('Use inherited actor as causer.', ['id' => $item['owner-id'], 'activity' => $activity['thread-completion'], 'owner' => $item['owner-link'], 'actor' => $actor['url']]);
 308                         } else {
 309                                 // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 310                                 $item['causer-link'] = $item['owner-link'];
 311                                 $item['causer-id'] = $item['owner-id'];
 312                                 Logger::info('Use actor as causer.', ['id' => $item['owner-id'], 'actor' => $item['owner-link']]);
 313                         }
 314
 315                         $item['owner-link'] = $item['author-link'];
 316                         $item['owner-id'] = $item['author-id'];
 317                 } else {
 318                         $actor = APContact::getByURL($item['owner-link'], false);
 319                         $item['isForum'] = ($actor['type'] == 'Group');
 320                 }
 321
 322                 $item['uri'] = $activity['id'];
 323
 324                 $item['created'] = DateTimeFormat::utc($activity['published']);
 325                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 326                 $guid = $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 327                 $item['guid'] = $activity['diaspora:guid'] ?: $guid;
 328
 329                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 330                 if (empty($item['uri-id'])) {
 331                         Logger::warning('Unable to get a uri-id for an item uri', ['uri' => $item['uri'], 'guid' => $item['guid']]);
 332                         return [];
 333                 }
 334
 335                 $item = self::processContent($activity, $item);
 336                 if (empty($item)) {
 337                         Logger::info('Message was not processed');
 338                         return [];
 339                 }
 340
 341                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 342
 343                 $item = self::constructAttachList($activity, $item);
 344
 345                 return $item;
 346         }
 347
 348         /**
 349          * Delete items
 350          *
 351          * @param array $activity
 352          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 353          * @throws \ImagickException
 354          */
 355         public static function deleteItem($activity)
 356         {
 357                 $owner = Contact::getIdForURL($activity['actor']);
 358
 359                 Logger::info('Deleting item', ['object' => $activity['object_id'], 'owner'  => $owner]);
 360                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 361         }
 362
 363         /**
 364          * Prepare the item array for an activity
 365          *
 366          * @param array $activity Activity array
 367          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 368          * @throws \ImagickException
 369          */
 370         public static function addTag($activity)
 371         {
 372                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 373                         return;
 374                 }
 375
 376                 foreach ($activity['receiver'] as $receiver) {
 377                         $item = Item::selectFirst(['id', 'uri-id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 378                         if (!DBA::isResult($item)) {
 379                                 // We don't fetch missing content for this purpose
 380                                 continue;
 381                         }
 382
 383                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 384                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 385                                 continue;
 386                         }
 387
 388                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 389                         Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 390                 }
 391         }
 392
 393         /**
 394          * Prepare the item array for an activity
 395          *
 396          * @param array  $activity Activity array
 397          * @param string $verb     Activity verb
 398          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 399          * @throws \ImagickException
 400          */
 401         public static function createActivity($activity, $verb)
 402         {
 403                 $item = self::createItem($activity);
 404                 $item['verb'] = $verb;
 405                 $item['thr-parent'] = $activity['object_id'];
 406                 $item['gravity'] = GRAVITY_ACTIVITY;
 407                 $item['object-type'] = Activity\ObjectType::NOTE;
 408
 409                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 410
 411                 self::postItem($activity, $item);
 412         }
 413
 414         /**
 415          * Create an event
 416          *
 417          * @param array $activity Activity array
 418          * @param array $item
 419          * @throws \Exception
 420          */
 421         public static function createEvent($activity, $item)
 422         {
 423                 $event['summary']  = HTML::toBBCode($activity['name']);
 424                 $event['desc']     = HTML::toBBCode($activity['content']);
 425                 $event['start']    = $activity['start-time'];
 426                 $event['finish']   = $activity['end-time'];
 427                 $event['nofinish'] = empty($event['finish']);
 428                 $event['location'] = $activity['location'];
 429                 $event['adjust']   = true;
 430                 $event['cid']      = $item['contact-id'];
 431                 $event['uid']      = $item['uid'];
 432                 $event['uri']      = $item['uri'];
 433                 $event['edited']   = $item['edited'];
 434                 $event['private']  = $item['private'];
 435                 $event['guid']     = $item['guid'];
 436                 $event['plink']    = $item['plink'];
 437
 438                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 439                 $ev = DBA::selectFirst('event', ['id'], $condition);
 440                 if (DBA::isResult($ev)) {
 441                         $event['id'] = $ev['id'];
 442                 }
 443
 444                 $event_id = Event::store($event);
 445                 Logger::info('Event was stored', ['id' => $event_id]);
 446         }
 447
 448         /**
 449          * Process the content
 450          *
 451          * @param array $activity Activity array
 452          * @param array $item
 453          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 454          * @throws \Exception
 455          */
 456         private static function processContent($activity, $item)
 457         {
 458                 $item['title'] = HTML::toBBCode($activity['name']);
 459
 460                 $content = HTML::toBBCode($activity['content']);
 461
 462                 if (!empty($activity['emojis'])) {
 463                         $content = self::replaceEmojis($content, $activity['emojis']);
 464                 }
 465
 466                 $content = self::convertMentions($content);
 467
 468                 if (!empty($activity['source'])) {
 469                         $item['body'] = $activity['source'];
 470                         $item['raw-body'] = $content;
 471                 } else {
 472                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 473                                 $item_private = !in_array(0, $activity['item_receiver']);
 474                                 $parent = Item::selectFirst(['id', 'uri-id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 475                                 if (!DBA::isResult($parent)) {
 476                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 477                                         return false;
 478                                 }
 479                                 if ($item_private && ($parent['private'] != Item::PRIVATE)) {
 480                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 481                                         return false;
 482                                 }
 483
 484                                 $content = self::removeImplicitMentionsFromBody($content, $parent);
 485                         }
 486                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 487                         $item['raw-body'] = $item['body'] = $content;
 488                 }
 489
 490                 self::storeFromBody($item);
 491                 self::storeTags($item['uri-id'], $activity['tags']);
 492
 493                 $item['location'] = $activity['location'];
 494
 495                 if (!empty($activity['latitude']) && !empty($activity['longitude'])) {
 496                         $item['coord'] = $activity['latitude'] . ' ' . $activity['longitude'];
 497                 }
 498
 499                 $item['app'] = $activity['generator'];
 500
 501                 return $item;
 502         }
 503
 504         /**
 505          * Store hashtags and mentions
 506          *
 507          * @param array $item
 508          */
 509         private static function storeFromBody(array $item)
 510         {
 511                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 512                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 513
 514                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 515         }
 516
 517         /**
 518          * Generate a GUID out of an URL
 519          *
 520          * @param string $url message URL
 521          * @return string with GUID
 522          */
 523         private static function getGUIDByURL(string $url)
 524         {
 525                 $parsed = parse_url($url);
 526
 527                 $host_hash = hash('crc32', $parsed['host']);
 528
 529                 unset($parsed["scheme"]);
 530                 unset($parsed["host"]);
 531
 532                 $path = implode("/", $parsed);
 533
 534                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 535         }
 536
 537         /**
 538          * Creates an item post
 539          *
 540          * @param array $activity Activity data
 541          * @param array $item     item array
 542          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 543          * @throws \ImagickException
 544          */
 545         public static function postItem(array $activity, array $item)
 546         {
 547                 if (empty($item)) {
 548                         return;
 549                 }
 550
 551                 $stored = false;
 552                 ksort($activity['receiver']);
 553
 554                 foreach ($activity['receiver'] as $receiver) {
 555                         if ($receiver == -1) {
 556                                 continue;
 557                         }
 558
 559                         $item['uid'] = $receiver;
 560
 561                         $type = $activity['reception_type'][$receiver] ?? Receiver::TARGET_UNKNOWN;
 562                         switch($type) {
 563                                 case Receiver::TARGET_TO:
 564                                         $item['post-type'] = Item::PT_TO;
 565                                         break;
 566                                 case Receiver::TARGET_CC:
 567                                         $item['post-type'] = Item::PT_CC;
 568                                         break;
 569                                 case Receiver::TARGET_BTO:
 570                                         $item['post-type'] = Item::PT_BTO;
 571                                         break;
 572                                 case Receiver::TARGET_BCC:
 573                                         $item['post-type'] = Item::PT_BCC;
 574                                         break;
 575                                 case Receiver::TARGET_FOLLOWER:
 576                                         $item['post-type'] = Item::PT_FOLLOWER;
 577                                         break;
 578                                 case Receiver::TARGET_ANSWER:
 579                                         $item['post-type'] = Item::PT_COMMENT;
 580                                         break;
 581                                 case Receiver::TARGET_GLOBAL:
 582                                         $item['post-type'] = Item::PT_GLOBAL;
 583                                         break;
 584                                 default:
 585                                         $item['post-type'] = Item::PT_ARTICLE;
 586                         }
 587
 588                         if (!empty($activity['from-relay'])) {
 589                                 $item['post-type'] = Item::PT_RELAY;
 590                         } elseif (!empty($activity['thread-completion'])) {
 591                                 $item['post-type'] = Item::PT_FETCHED;
 592                         }
 593
 594                         if ($item['isForum'] ?? false) {
 595                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver);
 596                         } else {
 597                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver);
 598                         }
 599
 600                         if (($receiver != 0) && empty($item['contact-id'])) {
 601                                 $item['contact-id'] = Contact::getIdForURL($activity['author']);
 602                         }
 603
 604                         if (!empty($activity['directmessage'])) {
 605                                 self::postMail($activity, $item);
 606                                 continue;
 607                         }
 608
 609                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 610                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 611
 612                                 if ($skip && (($activity['type'] == 'as:Announce') || ($item['isForum'] ?? false))) {
 613                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 614                                 }
 615
 616                                 if ($skip) {
 617                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 618                                         continue;
 619                                 }
 620
 621                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 622                         }
 623
 624                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 625                                 self::createEvent($activity, $item);
 626                         }
 627
 628                         $item_id = Item::insert($item);
 629                         if ($item_id) {
 630                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 631                         } else {
 632                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 633                         }
 634
 635                         if ($item['uid'] == 0) {
 636                                 $stored = $item_id;
 637                         }
 638                 }
 639
 640                 // Store send a follow request for every reshare - but only when the item had been stored
 641                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 642                         $author = APContact::getByURL($item['owner-link'], false);
 643                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 644                         if ($author['type'] != 'Group') {
 645                                 Logger::info('Send follow request', ['uri' => $item['uri'], 'stored' => $stored, 'to' => $item['author-link']]);
 646                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 647                         }
 648                 }
 649         }
 650
 651         /**
 652          * Store tags and mentions into the tag table
 653          *
 654          * @param integer $uriid
 655          * @param array $tags
 656          */
 657         private static function storeTags(int $uriid, array $tags = null)
 658         {
 659                 foreach ($tags as $tag) {
 660                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 661                                 continue;
 662                         }
 663
 664                         $hash = substr($tag['name'], 0, 1);
 665
 666                         if ($tag['type'] == 'Mention') {
 667                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 668                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 669                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 670                                         $tag['name'] = substr($tag['name'], 1);
 671                                 }
 672                                 $type = Tag::IMPLICIT_MENTION;
 673
 674                                 if (!empty($tag['href'])) {
 675                                         $apcontact = APContact::getByURL($tag['href']);
 676                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 677                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 678                                         }
 679                                 }
 680                         } elseif ($tag['type'] == 'Hashtag') {
 681                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 682                                         $tag['name'] = substr($tag['name'], 1);
 683                                 }
 684                                 $type = Tag::HASHTAG;
 685                         }
 686
 687                         if (empty($tag['name'])) {
 688                                 continue;
 689                         }
 690
 691                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 692                 }
 693         }
 694
 695         /**
 696          * Creates an mail post
 697          *
 698          * @param array $activity Activity data
 699          * @param array $item     item array
 700          * @return int|bool New mail table row id or false on error
 701          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 702          */
 703         private static function postMail($activity, $item)
 704         {
 705                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 706                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 707                         return false;
 708                 }
 709
 710                 Logger::info('Direct Message', $item);
 711
 712                 $msg = [];
 713                 $msg['uid'] = $item['uid'];
 714
 715                 $msg['contact-id'] = $item['contact-id'];
 716
 717                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 718                 $msg['from-name'] = $contact['name'];
 719                 $msg['from-url'] = $contact['url'];
 720                 $msg['from-photo'] = $contact['photo'];
 721
 722                 $msg['uri'] = $item['uri'];
 723                 $msg['created'] = $item['created'];
 724
 725                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 726                 if (DBA::isResult($parent)) {
 727                         $msg['parent-uri'] = $parent['parent-uri'];
 728                         $msg['title'] = $parent['title'];
 729                 } else {
 730                         $msg['parent-uri'] = $item['thr-parent'];
 731
 732                         if (!empty($item['title'])) {
 733                                 $msg['title'] = $item['title'];
 734                         } elseif (!empty($item['content-warning'])) {
 735                                 $msg['title'] = $item['content-warning'];
 736                         } else {
 737                                 // Trying to generate a title out of the body
 738                                 $title = $item['body'];
 739
 740                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 741                                         $title = $matches[3];
 742                                 }
 743
 744                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, BBCode::API, true), 0));
 745
 746                                 if (strlen($title) > 20) {
 747                                         $title = substr($title, 0, 20) . '...';
 748                                 }
 749
 750                                 $msg['title'] = $title;
 751                         }
 752                 }
 753                 $msg['body'] = $item['body'];
 754
 755                 return Mail::insert($msg);
 756         }
 757
 758         /**
 759          * Fetches missing posts
 760          *
 761          * @param string $url         message URL
 762          * @param array  $child       activity array with the child of this message
 763          * @param string $relay_actor Relay actor
 764          * @return string fetched message URL
 765          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 766          */
 767         public static function fetchMissingActivity(string $url, array $child = [], string $relay_actor = '')
 768         {
 769                 if (!empty($child['receiver'])) {
 770                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 771                 } else {
 772                         $uid = 0;
 773                 }
 774
 775                 $object = ActivityPub::fetchContent($url, $uid);
 776                 if (empty($object)) {
 777                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 778                         return '';
 779                 }
 780
 781                 if (empty($object['id'])) {
 782                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 783                         return '';
 784                 }
 785
 786                 if (!empty($object['actor'])) {
 787                         $object_actor = $object['actor'];
 788                 } elseif (!empty($object['attributedTo'])) {
 789                         $object_actor = $object['attributedTo'];
 790                         if (is_array($object_actor)) {
 791                                 $compacted = JsonLD::compact($object);
 792                                 $object_actor = JsonLD::fetchElement($compacted, 'as:attributedTo', '@id');
 793                         }
 794                 } else {
 795                         // Shouldn't happen
 796                         $object_actor = '';
 797                 }
 798
 799                 $signer = [$object_actor];
 800
 801                 if (!empty($child['author'])) {
 802                         $actor = $child['author'];
 803                         $signer[] = $actor;
 804                 } else {
 805                         $actor = $object_actor;
 806                 }
 807
 808                 if (!empty($object['published'])) {
 809                         $published = $object['published'];
 810                 } elseif (!empty($child['published'])) {
 811                         $published = $child['published'];
 812                 } else {
 813                         $published = DateTimeFormat::utcNow();
 814                 }
 815
 816                 $activity = [];
 817                 $activity['@context'] = $object['@context'];
 818                 unset($object['@context']);
 819                 $activity['id'] = $object['id'];
 820                 $activity['to'] = $object['to'] ?? [];
 821                 $activity['cc'] = $object['cc'] ?? [];
 822                 $activity['actor'] = $actor;
 823                 $activity['object'] = $object;
 824                 $activity['published'] = $published;
 825                 $activity['type'] = 'Create';
 826
 827                 $ldactivity = JsonLD::compact($activity);
 828
 829                 if (!empty($relay_actor)) {
 830                         $ldactivity['thread-completion'] = $ldactivity['from-relay'] = Contact::getIdForURL($relay_actor);
 831                 } elseif (!empty($child['thread-completion'])) {
 832                         $ldactivity['thread-completion'] = $child['thread-completion'];
 833                 } else {
 834                         $ldactivity['thread-completion'] = Contact::getIdForURL($actor);
 835                 }
 836
 837                 if (!empty($relay_actor) && !self::acceptIncomingMessage($ldactivity, $object['id'])) {
 838                         return '';
 839                 }
 840
 841                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity), $uid, true, false, $signer);
 842
 843                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 844
 845                 return $activity['id'];
 846         }
 847
 848         /**
 849          * Test if incoming relay messages should be accepted
 850          *
 851          * @param array $activity activity array
 852          * @param string $id      object ID
 853          * @return boolean true if message is accepted
 854          */
 855         private static function acceptIncomingMessage(array $activity, string $id)
 856         {
 857                 if (empty($activity['as:object'])) {
 858                         Logger::info('No object field in activity - accepted', ['id' => $id]);
 859                         return true;
 860                 }
 861
 862                 $replyto = JsonLD::fetchElement($activity['as:object'], 'as:inReplyTo', '@id');
 863                 if (Item::exists(['uri' => $replyto])) {
 864                         Logger::info('Post is a reply to an existing post - accepted', ['id' => $id, 'replyto' => $replyto]);
 865                         return true;
 866                 }
 867
 868                 $attributed_to = JsonLD::fetchElement($activity['as:object'], 'as:attributedTo', '@id');
 869                 $authorid = Contact::getIdForURL($attributed_to);
 870
 871                 $body = HTML::toBBCode(JsonLD::fetchElement($activity['as:object'], 'as:content', '@value'));
 872
 873                 $messageTags = [];
 874                 $tags = Receiver::processTags(JsonLD::fetchElementArray($activity['as:object'], 'as:tag') ?? []);
 875                 if (!empty($tags)) {
 876                         foreach ($tags as $tag) {
 877                                 if ($tag['type'] != 'Hashtag') {
 878                                         continue;
 879                                 }
 880                                 $messageTags[] = ltrim(mb_strtolower($tag['name']), '#');
 881                         }
 882                 }
 883
 884                 return Relay::isSolicitedPost($messageTags, $body, $authorid, $id, Protocol::ACTIVITYPUB);
 885         }
 886
 887         /**
 888          * perform a "follow" request
 889          *
 890          * @param array $activity
 891          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 892          * @throws \ImagickException
 893          */
 894         public static function followUser($activity)
 895         {
 896                 $uid = User::getIdForURL($activity['object_id']);
 897                 if (empty($uid)) {
 898                         return;
 899                 }
 900
 901                 $owner = User::getOwnerDataById($uid);
 902                 if (empty($owner)) {
 903                         return;
 904                 }
 905
 906                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 907                 if (!empty($cid)) {
 908                         self::switchContact($cid);
 909                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 910                 }
 911
 912                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 913                         'author-link' => $activity['actor']];
 914
 915                 // Ensure that the contact has got the right network type
 916                 self::switchContact($item['author-id']);
 917
 918                 $result = Contact::addRelationship($owner, [], $item, false, $activity['content'] ?? '');
 919                 if ($result === true) {
 920                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $activity['id'], $owner['uid']);
 921                 }
 922
 923                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 924                 if (empty($cid)) {
 925                         return;
 926                 }
 927
 928                 if (empty($contact)) {
 929                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 930                 }
 931
 932                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 933         }
 934
 935         /**
 936          * Update the given profile
 937          *
 938          * @param array $activity
 939          * @throws \Exception
 940          */
 941         public static function updatePerson($activity)
 942         {
 943                 if (empty($activity['object_id'])) {
 944                         return;
 945                 }
 946
 947                 Logger::info('Updating profile', ['object' => $activity['object_id']]);
 948                 Contact::updateFromProbeByURL($activity['object_id']);
 949         }
 950
 951         /**
 952          * Delete the given profile
 953          *
 954          * @param array $activity
 955          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 956          */
 957         public static function deletePerson($activity)
 958         {
 959                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 960                         Logger::info('Empty object id or actor.');
 961                         return;
 962                 }
 963
 964                 if ($activity['object_id'] != $activity['actor']) {
 965                         Logger::info('Object id does not match actor.');
 966                         return;
 967                 }
 968
 969                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 970                 while ($contact = DBA::fetch($contacts)) {
 971                         Contact::remove($contact['id']);
 972                 }
 973                 DBA::close($contacts);
 974
 975                 Logger::info('Deleted contact', ['object' => $activity['object_id']]);
 976         }
 977
 978         /**
 979          * Accept a follow request
 980          *
 981          * @param array $activity
 982          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 983          * @throws \ImagickException
 984          */
 985         public static function acceptFollowUser($activity)
 986         {
 987                 $uid = User::getIdForURL($activity['object_actor']);
 988                 if (empty($uid)) {
 989                         return;
 990                 }
 991
 992                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 993                 if (empty($cid)) {
 994                         Logger::info('No contact found', ['actor' => $activity['actor']]);
 995                         return;
 996                 }
 997
 998                 self::switchContact($cid);
 999
1000                 $fields = ['pending' => false];
1001
1002                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1003                 if ($contact['rel'] == Contact::FOLLOWER) {
1004                         $fields['rel'] = Contact::FRIEND;
1005                 }
1006
1007                 $condition = ['id' => $cid];
1008                 DBA::update('contact', $fields, $condition);
1009                 Logger::info('Accept contact request', ['contact' => $cid, 'user' => $uid]);
1010         }
1011
1012         /**
1013          * Reject a follow request
1014          *
1015          * @param array $activity
1016          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1017          * @throws \ImagickException
1018          */
1019         public static function rejectFollowUser($activity)
1020         {
1021                 $uid = User::getIdForURL($activity['object_actor']);
1022                 if (empty($uid)) {
1023                         return;
1024                 }
1025
1026                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1027                 if (empty($cid)) {
1028                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1029                         return;
1030                 }
1031
1032                 self::switchContact($cid);
1033
1034                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
1035                         Contact::remove($cid);
1036                         Logger::info('Rejected contact request - contact removed', ['contact' => $cid, 'user' => $uid]);
1037                 } else {
1038                         Logger::info('Rejected contact request', ['contact' => $cid, 'user' => $uid]);
1039                 }
1040         }
1041
1042         /**
1043          * Undo activity like "like" or "dislike"
1044          *
1045          * @param array $activity
1046          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1047          * @throws \ImagickException
1048          */
1049         public static function undoActivity($activity)
1050         {
1051                 if (empty($activity['object_id'])) {
1052                         return;
1053                 }
1054
1055                 if (empty($activity['object_actor'])) {
1056                         return;
1057                 }
1058
1059                 $author_id = Contact::getIdForURL($activity['object_actor']);
1060                 if (empty($author_id)) {
1061                         return;
1062                 }
1063
1064                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1065         }
1066
1067         /**
1068          * Activity to remove a follower
1069          *
1070          * @param array $activity
1071          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1072          * @throws \ImagickException
1073          */
1074         public static function undoFollowUser($activity)
1075         {
1076                 $uid = User::getIdForURL($activity['object_object']);
1077                 if (empty($uid)) {
1078                         return;
1079                 }
1080
1081                 $owner = User::getOwnerDataById($uid);
1082                 if (empty($owner)) {
1083                         return;
1084                 }
1085
1086                 $cid = Contact::getIdForURL($activity['actor'], $uid);
1087                 if (empty($cid)) {
1088                         Logger::info('No contact found', ['actor' => $activity['actor']]);
1089                         return;
1090                 }
1091
1092                 self::switchContact($cid);
1093
1094                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1095                 if (!DBA::isResult($contact)) {
1096                         return;
1097                 }
1098
1099                 Contact::removeFollower($owner, $contact);
1100                 Logger::info('Undo following request', ['contact' => $cid, 'user' => $uid]);
1101         }
1102
1103         /**
1104          * Switches a contact to AP if needed
1105          *
1106          * @param integer $cid Contact ID
1107          * @throws \Exception
1108          */
1109         private static function switchContact($cid)
1110         {
1111                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
1112                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
1113                         return;
1114                 }
1115
1116                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1117                 Contact::updateFromProbe($cid);
1118         }
1119
1120         /**
1121          * Collects implicit mentions like:
1122          * - the author of the parent item
1123          * - all the mentioned conversants in the parent item
1124          *
1125          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1126          * @return array
1127          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1128          */
1129         private static function getImplicitMentionList(array $parent)
1130         {
1131                 $parent_terms = Tag::getByURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1132
1133                 $parent_author = Contact::getByURL($parent['author-link'], false, ['url', 'nurl', 'alias']);
1134
1135                 $implicit_mentions = [];
1136                 if (empty($parent_author['url'])) {
1137                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1138                 } else {
1139                         $implicit_mentions[] = $parent_author['url'];
1140                         $implicit_mentions[] = $parent_author['nurl'];
1141                         $implicit_mentions[] = $parent_author['alias'];
1142                 }
1143
1144                 if (!empty($parent['alias'])) {
1145                         $implicit_mentions[] = $parent['alias'];
1146                 }
1147
1148                 foreach ($parent_terms as $term) {
1149                         $contact = Contact::getByURL($term['url'], false, ['url', 'nurl', 'alias']);
1150                         if (!empty($contact['url'])) {
1151                                 $implicit_mentions[] = $contact['url'];
1152                                 $implicit_mentions[] = $contact['nurl'];
1153                                 $implicit_mentions[] = $contact['alias'];
1154                         }
1155                 }
1156
1157                 return $implicit_mentions;
1158         }
1159
1160         /**
1161          * Strips from the body prepended implicit mentions
1162          *
1163          * @param string $body
1164          * @param array $parent
1165          * @return string
1166          */
1167         private static function removeImplicitMentionsFromBody(string $body, array $parent)
1168         {
1169                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1170                         return $body;
1171                 }
1172
1173                 $potential_mentions = self::getImplicitMentionList($parent);
1174
1175                 $kept_mentions = [];
1176
1177                 // Extract one prepended mention at a time from the body
1178                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1179                         if (!in_array($matches[2], $potential_mentions)) {
1180                                 $kept_mentions[] = $matches[1];
1181                         }
1182
1183                         $body = $matches[3];
1184                 }
1185
1186                 // Re-appending the kept mentions to the body after extraction
1187                 $kept_mentions[] = $body;
1188
1189                 return implode('', $kept_mentions);
1190         }
1191 }