src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub/Processor.php
   4  */
   5 namespace Friendica\Protocol\ActivityPub;
   6
   7 use Friendica\Content\Text\BBCode;
   8 use Friendica\Content\Text\HTML;
   9 use Friendica\Core\Config;
  10 use Friendica\Core\Logger;
  11 use Friendica\Core\PConfig;
  12 use Friendica\Core\Protocol;
  13 use Friendica\Database\DBA;
  14 use Friendica\DI;
  15 use Friendica\Model\APContact;
  16 use Friendica\Model\Contact;
  17 use Friendica\Model\Event;
  18 use Friendica\Model\Item;
  19 use Friendica\Model\Mail;
  20 use Friendica\Model\Term;
  21 use Friendica\Model\User;
  22 use Friendica\Protocol\Activity;
  23 use Friendica\Protocol\ActivityPub;
  24 use Friendica\Util\DateTimeFormat;
  25 use Friendica\Util\JsonLD;
  26 use Friendica\Util\Strings;
  27
  28 /**
  29  * ActivityPub Processor Protocol class
  30  */
  31 class Processor
  32 {
  33         /**
  34          * Converts mentions from Pleroma into the Friendica format
  35          *
  36          * @param string $body
  37          *
  38          * @return string converted body
  39          */
  40         private static function convertMentions($body)
  41         {
  42                 $URLSearchString = "^\[\]";
  43                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
  44
  45                 return $body;
  46         }
  47
  48         /**
  49          * Replaces emojis in the body
  50          *
  51          * @param array $emojis
  52          * @param string $body
  53          *
  54          * @return string with replaced emojis
  55          */
  56         private static function replaceEmojis($body, array $emojis)
  57         {
  58                 foreach ($emojis as $emoji) {
  59                         $replace = '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
  60                         $body = str_replace($emoji['name'], $replace, $body);
  61                 }
  62                 return $body;
  63         }
  64
  65         /**
  66          * Constructs a string with tags for a given tag array
  67          *
  68          * @param array   $tags
  69          * @param boolean $sensitive
  70          * @return string with tags
  71          */
  72         private static function constructTagString(array $tags = null, $sensitive = false)
  73         {
  74                 if (empty($tags)) {
  75                         return '';
  76                 }
  77
  78                 $tag_text = '';
  79                 foreach ($tags as $tag) {
  80                         if (in_array($tag['type'] ?? '', ['Mention', 'Hashtag'])) {
  81                                 if (!empty($tag_text)) {
  82                                         $tag_text .= ',';
  83                                 }
  84
  85                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
  86                         }
  87                 }
  88
  89                 /// @todo add nsfw for $sensitive
  90
  91                 return $tag_text;
  92         }
  93
  94         /**
  95          * Add attachment data to the item array
  96          *
  97          * @param array   $activity
  98          * @param array   $item
  99          *
 100          * @return array array
 101          */
 102         private static function constructAttachList($activity, $item)
 103         {
 104                 if (empty($activity['attachments'])) {
 105                         return $item;
 106                 }
 107
 108                 foreach ($activity['attachments'] as $attach) {
 109                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 110                         if ($filetype == 'image') {
 111                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 112                                         continue;
 113                                 }
 114
 115                                 if (empty($attach['name'])) {
 116                                         $item['body'] .= "\n[img]" . $attach['url'] . '[/img]';
 117                                 } else {
 118                                         $item['body'] .= "\n[img=" . $attach['url'] . ']' . $attach['name'] . '[/img]';
 119                                 }
 120                         } else {
 121                                 if (!empty($item["attach"])) {
 122                                         $item["attach"] .= ',';
 123                                 } else {
 124                                         $item["attach"] = '';
 125                                 }
 126                                 if (!isset($attach['length'])) {
 127                                         $attach['length'] = "0";
 128                                 }
 129                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.($attach['name'] ?? '') .'"[/attach]';
 130                         }
 131                 }
 132
 133                 return $item;
 134         }
 135
 136         /**
 137          * Updates a message
 138          *
 139          * @param array $activity Activity array
 140          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 141          */
 142         public static function updateItem($activity)
 143         {
 144                 $item = Item::selectFirst(['uri', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 145                 if (!DBA::isResult($item)) {
 146                         Logger::warning('Unknown item', ['uri' => $activity['id']]);
 147                         return;
 148                 }
 149
 150                 $item['changed'] = DateTimeFormat::utcNow();
 151                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 152
 153                 $item = self::processContent($activity, $item);
 154                 if (empty($item)) {
 155                         return;
 156                 }
 157
 158                 Item::update($item, ['uri' => $activity['id']]);
 159         }
 160
 161         /**
 162          * Prepares data for a message
 163          *
 164          * @param array $activity Activity array
 165          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 166          * @throws \ImagickException
 167          */
 168         public static function createItem($activity)
 169         {
 170                 $item = [];
 171                 $item['verb'] = Activity::POST;
 172                 $item['thr-parent'] = $activity['reply-to-id'];
 173
 174                 if ($activity['reply-to-id'] == $activity['id']) {
 175                         $item['gravity'] = GRAVITY_PARENT;
 176                         $item['object-type'] = Activity\ObjectType::NOTE;
 177                 } else {
 178                         $item['gravity'] = GRAVITY_COMMENT;
 179                         $item['object-type'] = Activity\ObjectType::COMMENT;
 180
 181                         // Ensure that the comment reaches all receivers of the referring post
 182                         $activity['receiver'] = self::addReceivers($activity);
 183                 }
 184
 185                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 186                         Logger::log('Parent ' . $activity['reply-to-id'] . ' not found. Try to refetch it.');
 187                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 188                 }
 189
 190                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 191
 192                 self::postItem($activity, $item);
 193         }
 194
 195         /**
 196          * Delete items
 197          *
 198          * @param array $activity
 199          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 200          * @throws \ImagickException
 201          */
 202         public static function deleteItem($activity)
 203         {
 204                 $owner = Contact::getIdForURL($activity['actor']);
 205
 206                 Logger::log('Deleting item ' . $activity['object_id'] . ' from ' . $owner, Logger::DEBUG);
 207                 Item::delete(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 208         }
 209
 210         /**
 211          * Prepare the item array for an activity
 212          *
 213          * @param array $activity Activity array
 214          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 215          * @throws \ImagickException
 216          */
 217         public static function addTag($activity)
 218         {
 219                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 220                         return;
 221                 }
 222
 223                 foreach ($activity['receiver'] as $receiver) {
 224                         $item = Item::selectFirst(['id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 225                         if (!DBA::isResult($item)) {
 226                                 // We don't fetch missing content for this purpose
 227                                 continue;
 228                         }
 229
 230                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 231                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 232                                 continue;
 233                         }
 234
 235                         // To-Do:
 236                         // - Check if "blocktag" is set
 237                         // - Check if actor is a contact
 238
 239                         if (!stristr($item['tag'], trim($activity['object_content']))) {
 240                                 $tag = $item['tag'] . (strlen($item['tag']) ? ',' : '') . '#[url=' . $activity['object_id'] . ']'. $activity['object_content'] . '[/url]';
 241                                 Item::update(['tag' => $tag], ['id' => $item['id']]);
 242                                 Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 243                         }
 244                 }
 245         }
 246
 247         /**
 248          * Add users to the receiver list of the given public activity.
 249          * This is used to ensure that the activity will be stored in every thread.
 250          *
 251          * @param array $activity Activity array
 252          * @return array Modified receiver list
 253          */
 254         private static function addReceivers(array $activity)
 255         {
 256                 if (!in_array(0, $activity['receiver'])) {
 257                         // Private activities will not be modified
 258                         return $activity['receiver'];
 259                 }
 260
 261                 // Add all owners of the referring item to the receivers
 262                 $original = $receivers = $activity['receiver'];
 263                 $items = Item::select(['uid'], ['uri' => $activity['object_id']]);
 264                 while ($item = DBA::fetch($items)) {
 265                         $receivers['uid:' . $item['uid']] = $item['uid'];
 266                 }
 267                 DBA::close($items);
 268
 269                 if (count($original) != count($receivers)) {
 270                         Logger::info('Improved data', ['id' => $activity['id'], 'object' => $activity['object_id'], 'original' => $original, 'improved' => $receivers]);
 271                 }
 272
 273                 return $receivers;
 274         }
 275
 276         /**
 277          * Prepare the item array for an activity
 278          *
 279          * @param array  $activity Activity array
 280          * @param string $verb     Activity verb
 281          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 282          * @throws \ImagickException
 283          */
 284         public static function createActivity($activity, $verb)
 285         {
 286                 $item = [];
 287                 $item['verb'] = $verb;
 288                 $item['thr-parent'] = $activity['object_id'];
 289                 $item['gravity'] = GRAVITY_ACTIVITY;
 290                 $item['object-type'] = Activity\ObjectType::NOTE;
 291
 292                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 293
 294                 $activity['receiver'] = self::addReceivers($activity);
 295
 296                 self::postItem($activity, $item);
 297         }
 298
 299         /**
 300          * Create an event
 301          *
 302          * @param array $activity Activity array
 303          * @param array $item
 304          * @throws \Exception
 305          */
 306         public static function createEvent($activity, $item)
 307         {
 308                 $event['summary']  = HTML::toBBCode($activity['name']);
 309                 $event['desc']     = HTML::toBBCode($activity['content']);
 310                 $event['start']    = $activity['start-time'];
 311                 $event['finish']   = $activity['end-time'];
 312                 $event['nofinish'] = empty($event['finish']);
 313                 $event['location'] = $activity['location'];
 314                 $event['adjust']   = true;
 315                 $event['cid']      = $item['contact-id'];
 316                 $event['uid']      = $item['uid'];
 317                 $event['uri']      = $item['uri'];
 318                 $event['edited']   = $item['edited'];
 319                 $event['private']  = $item['private'];
 320                 $event['guid']     = $item['guid'];
 321                 $event['plink']    = $item['plink'];
 322
 323                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 324                 $ev = DBA::selectFirst('event', ['id'], $condition);
 325                 if (DBA::isResult($ev)) {
 326                         $event['id'] = $ev['id'];
 327                 }
 328
 329                 $event_id = Event::store($event);
 330                 Logger::log('Event '.$event_id.' was stored', Logger::DEBUG);
 331         }
 332
 333         /**
 334          * Process the content
 335          *
 336          * @param array $activity Activity array
 337          * @param array $item
 338          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 339          * @throws \Exception
 340          */
 341         private static function processContent($activity, $item)
 342         {
 343                 $item['title'] = HTML::toBBCode($activity['name']);
 344
 345                 if (!empty($activity['source'])) {
 346                         $item['body'] = $activity['source'];
 347                 } else {
 348                         $content = HTML::toBBCode($activity['content']);
 349
 350                         if (!empty($activity['emojis'])) {
 351                                 $content = self::replaceEmojis($content, $activity['emojis']);
 352                         }
 353
 354                         $content = self::convertMentions($content);
 355
 356                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 357                                 $item_private = !in_array(0, $activity['item_receiver']);
 358                                 $parent = Item::selectFirst(['id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 359                                 if (!DBA::isResult($parent)) {
 360                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 361                                         return false;
 362                                 }
 363                                 if ($item_private && !$parent['private']) {
 364                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 365                                         return false;
 366                                 }
 367
 368                                 $potential_implicit_mentions = self::getImplicitMentionList($parent);
 369                                 $content = self::removeImplicitMentionsFromBody($content, $potential_implicit_mentions);
 370                                 $activity['tags'] = self::convertImplicitMentionsInTags($activity['tags'], $potential_implicit_mentions);
 371                         }
 372                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 373                         $item['body'] = $content;
 374
 375                         if (($activity['object_type'] == 'as:Video') && !empty($activity['alternate-url'])) {
 376                                 $item['body'] .= "\n[video]" . $activity['alternate-url'] . '[/video]';
 377                         }
 378                 }
 379
 380                 $item['tag'] = self::constructTagString($activity['tags'], $activity['sensitive']);
 381
 382                 $item['location'] = $activity['location'];
 383
 384                 if (!empty($item['latitude']) && !empty($item['longitude'])) {
 385                         $item['coord'] = $item['latitude'] . ' ' . $item['longitude'];
 386                 }
 387
 388                 $item['app'] = $activity['generator'];
 389
 390                 return $item;
 391         }
 392
 393         /**
 394          * Creates an item post
 395          *
 396          * @param array $activity Activity data
 397          * @param array $item     item array
 398          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 399          * @throws \ImagickException
 400          */
 401         private static function postItem($activity, $item)
 402         {
 403                 /// @todo What to do with $activity['context']?
 404                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 405                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 406                         return;
 407                 }
 408
 409                 $item['network'] = Protocol::ACTIVITYPUB;
 410                 $item['private'] = !in_array(0, $activity['receiver']);
 411                 $item['author-link'] = $activity['author'];
 412                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
 413                 $item['owner-link'] = $activity['actor'];
 414                 $item['owner-id'] = Contact::getIdForURL($activity['actor'], 0, true);
 415
 416                 $isForum = false;
 417
 418                 if (!empty($activity['thread-completion'])) {
 419                         // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 420                         $item['causer-link'] = $item['owner-link'];
 421                         $item['causer-id'] = $item['owner-id'];
 422
 423                         Logger::info('Ignoring actor because of thread completion.', ['actor' => $item['owner-link']]);
 424                         $item['owner-link'] = $item['author-link'];
 425                         $item['owner-id'] = $item['author-id'];
 426                 } else {
 427                         $actor = APContact::getByURL($item['owner-link'], false);
 428                         $isForum = ($actor['type'] == 'Group');
 429                 }
 430
 431                 $item['uri'] = $activity['id'];
 432
 433                 $item['created'] = DateTimeFormat::utc($activity['published']);
 434                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 435                 $item['guid'] = $activity['diaspora:guid'];
 436
 437                 $item = self::processContent($activity, $item);
 438                 if (empty($item)) {
 439                         return;
 440                 }
 441
 442                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 443
 444                 $item = self::constructAttachList($activity, $item);
 445
 446                 $stored = false;
 447
 448                 foreach ($activity['receiver'] as $receiver) {
 449                         $item['uid'] = $receiver;
 450
 451                         if ($isForum) {
 452                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver, true);
 453                         } else {
 454                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
 455                         }
 456
 457                         if (($receiver != 0) && empty($item['contact-id'])) {
 458                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
 459                         }
 460
 461                         if (!empty($activity['directmessage'])) {
 462                                 self::postMail($activity, $item);
 463                                 continue;
 464                         }
 465
 466                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 467                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 468
 469                                 if ($skip && (($activity['type'] == 'as:Announce') || $isForum)) {
 470                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 471                                 }
 472
 473                                 if ($skip) {
 474                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 475                                         continue;
 476                                 }
 477
 478                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 479                         }
 480
 481                         if ($activity['object_type'] == 'as:Event') {
 482                                 self::createEvent($activity, $item);
 483                         }
 484
 485                         $item_id = Item::insert($item);
 486                         if ($item_id) {
 487                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 488                         } else {
 489                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 490                         }
 491
 492                         if ($item['uid'] == 0) {
 493                                 $stored = $item_id;
 494                         }
 495                 }
 496
 497                 // Store send a follow request for every reshare - but only when the item had been stored
 498                 if ($stored && !$item['private'] && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 499                         $author = APContact::getByURL($item['owner-link'], false);
 500                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 501                         if ($author['type'] != 'Group') {
 502                                 Logger::log('Send follow request for ' . $item['uri'] . ' (' . $stored . ') to ' . $item['author-link'], Logger::DEBUG);
 503                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 504                         }
 505                 }
 506         }
 507
 508         /**
 509          * Creates an mail post
 510          *
 511          * @param array $activity Activity data
 512          * @param array $item     item array
 513          * @return int|bool New mail table row id or false on error
 514          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 515          */
 516         private static function postMail($activity, $item)
 517         {
 518                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 519                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 520                         return false;
 521                 }
 522
 523                 Logger::info('Direct Message', $item);
 524
 525                 $msg = [];
 526                 $msg['uid'] = $item['uid'];
 527
 528                 $msg['contact-id'] = $item['contact-id'];
 529
 530                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 531                 $msg['from-name'] = $contact['name'];
 532                 $msg['from-url'] = $contact['url'];
 533                 $msg['from-photo'] = $contact['photo'];
 534
 535                 $msg['uri'] = $item['uri'];
 536                 $msg['created'] = $item['created'];
 537
 538                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 539                 if (DBA::isResult($parent)) {
 540                         $msg['parent-uri'] = $parent['parent-uri'];
 541                         $msg['title'] = $parent['title'];
 542                 } else {
 543                         $msg['parent-uri'] = $item['thr-parent'];
 544
 545                         if (!empty($item['title'])) {
 546                                 $msg['title'] = $item['title'];
 547                         } elseif (!empty($item['content-warning'])) {
 548                                 $msg['title'] = $item['content-warning'];
 549                         } else {
 550                                 // Trying to generate a title out of the body
 551                                 $title = $item['body'];
 552
 553                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 554                                         $title = $matches[3];
 555                                 }
 556
 557                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, 2, true), 0));
 558
 559                                 if (strlen($title) > 20) {
 560                                         $title = substr($title, 0, 20) . '...';
 561                                 }
 562
 563                                 $msg['title'] = $title;
 564                         }
 565                 }
 566                 $msg['body'] = $item['body'];
 567
 568                 return Mail::insert($msg);
 569         }
 570
 571         /**
 572          * Fetches missing posts
 573          *
 574          * @param string $url message URL
 575          * @param array $child activity array with the child of this message
 576          * @return boolean success
 577          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 578          */
 579         public static function fetchMissingActivity($url, $child = [])
 580         {
 581                 if (!empty($child['receiver'])) {
 582                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 583                 } else {
 584                         $uid = 0;
 585                 }
 586
 587                 $object = ActivityPub::fetchContent($url, $uid);
 588                 if (empty($object)) {
 589                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 590                         return false;
 591                 }
 592
 593                 if (empty($object['id'])) {
 594                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 595                         return false;
 596                 }
 597
 598                 if (!empty($child['author'])) {
 599                         $actor = $child['author'];
 600                 } elseif (!empty($object['actor'])) {
 601                         $actor = $object['actor'];
 602                 } elseif (!empty($object['attributedTo'])) {
 603                         $actor = $object['attributedTo'];
 604                 } else {
 605                         // Shouldn't happen
 606                         $actor = '';
 607                 }
 608
 609                 if (!empty($object['published'])) {
 610                         $published = $object['published'];
 611                 } elseif (!empty($child['published'])) {
 612                         $published = $child['published'];
 613                 } else {
 614                         $published = DateTimeFormat::utcNow();
 615                 }
 616
 617                 $activity = [];
 618                 $activity['@context'] = $object['@context'];
 619                 unset($object['@context']);
 620                 $activity['id'] = $object['id'];
 621                 $activity['to'] = $object['to'] ?? [];
 622                 $activity['cc'] = $object['cc'] ?? [];
 623                 $activity['actor'] = $actor;
 624                 $activity['object'] = $object;
 625                 $activity['published'] = $published;
 626                 $activity['type'] = 'Create';
 627
 628                 $ldactivity = JsonLD::compact($activity);
 629
 630                 $ldactivity['thread-completion'] = true;
 631
 632                 ActivityPub\Receiver::processActivity($ldactivity);
 633                 Logger::log('Activity ' . $url . ' had been fetched and processed.');
 634
 635                 return true;
 636         }
 637
 638         /**
 639          * perform a "follow" request
 640          *
 641          * @param array $activity
 642          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 643          * @throws \ImagickException
 644          */
 645         public static function followUser($activity)
 646         {
 647                 $uid = User::getIdForURL($activity['object_id']);
 648                 if (empty($uid)) {
 649                         return;
 650                 }
 651
 652                 $owner = User::getOwnerDataById($uid);
 653
 654                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 655                 if (!empty($cid)) {
 656                         self::switchContact($cid);
 657                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 658                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 659                 } else {
 660                         $contact = [];
 661                 }
 662
 663                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 664                         'author-link' => $activity['actor']];
 665
 666                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 667
 668                 // Ensure that the contact has got the right network type
 669                 self::switchContact($item['author-id']);
 670
 671                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 672                 if ($result === true) {
 673                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $item['author-id'], $owner['uid']);
 674                 }
 675
 676                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 677                 if (empty($cid)) {
 678                         return;
 679                 }
 680
 681                 if (empty($contact)) {
 682                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 683                 }
 684
 685                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 686         }
 687
 688         /**
 689          * Update the given profile
 690          *
 691          * @param array $activity
 692          * @throws \Exception
 693          */
 694         public static function updatePerson($activity)
 695         {
 696                 if (empty($activity['object_id'])) {
 697                         return;
 698                 }
 699
 700                 Logger::log('Updating profile for ' . $activity['object_id'], Logger::DEBUG);
 701                 Contact::updateFromProbeByURL($activity['object_id'], true);
 702         }
 703
 704         /**
 705          * Delete the given profile
 706          *
 707          * @param array $activity
 708          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 709          */
 710         public static function deletePerson($activity)
 711         {
 712                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 713                         Logger::log('Empty object id or actor.', Logger::DEBUG);
 714                         return;
 715                 }
 716
 717                 if ($activity['object_id'] != $activity['actor']) {
 718                         Logger::log('Object id does not match actor.', Logger::DEBUG);
 719                         return;
 720                 }
 721
 722                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 723                 while ($contact = DBA::fetch($contacts)) {
 724                         Contact::remove($contact['id']);
 725                 }
 726                 DBA::close($contacts);
 727
 728                 Logger::log('Deleted contact ' . $activity['object_id'], Logger::DEBUG);
 729         }
 730
 731         /**
 732          * Accept a follow request
 733          *
 734          * @param array $activity
 735          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 736          * @throws \ImagickException
 737          */
 738         public static function acceptFollowUser($activity)
 739         {
 740                 $uid = User::getIdForURL($activity['object_actor']);
 741                 if (empty($uid)) {
 742                         return;
 743                 }
 744
 745                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 746                 if (empty($cid)) {
 747                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 748                         return;
 749                 }
 750
 751                 self::switchContact($cid);
 752
 753                 $fields = ['pending' => false];
 754
 755                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 756                 if ($contact['rel'] == Contact::FOLLOWER) {
 757                         $fields['rel'] = Contact::FRIEND;
 758                 }
 759
 760                 $condition = ['id' => $cid];
 761                 DBA::update('contact', $fields, $condition);
 762                 Logger::log('Accept contact request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 763         }
 764
 765         /**
 766          * Reject a follow request
 767          *
 768          * @param array $activity
 769          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 770          * @throws \ImagickException
 771          */
 772         public static function rejectFollowUser($activity)
 773         {
 774                 $uid = User::getIdForURL($activity['object_actor']);
 775                 if (empty($uid)) {
 776                         return;
 777                 }
 778
 779                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 780                 if (empty($cid)) {
 781                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 782                         return;
 783                 }
 784
 785                 self::switchContact($cid);
 786
 787                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
 788                         Contact::remove($cid);
 789                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . ' - contact had been removed.', Logger::DEBUG);
 790                 } else {
 791                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . '.', Logger::DEBUG);
 792                 }
 793         }
 794
 795         /**
 796          * Undo activity like "like" or "dislike"
 797          *
 798          * @param array $activity
 799          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 800          * @throws \ImagickException
 801          */
 802         public static function undoActivity($activity)
 803         {
 804                 if (empty($activity['object_id'])) {
 805                         return;
 806                 }
 807
 808                 if (empty($activity['object_actor'])) {
 809                         return;
 810                 }
 811
 812                 $author_id = Contact::getIdForURL($activity['object_actor']);
 813                 if (empty($author_id)) {
 814                         return;
 815                 }
 816
 817                 Item::delete(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
 818         }
 819
 820         /**
 821          * Activity to remove a follower
 822          *
 823          * @param array $activity
 824          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 825          * @throws \ImagickException
 826          */
 827         public static function undoFollowUser($activity)
 828         {
 829                 $uid = User::getIdForURL($activity['object_object']);
 830                 if (empty($uid)) {
 831                         return;
 832                 }
 833
 834                 $owner = User::getOwnerDataById($uid);
 835
 836                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 837                 if (empty($cid)) {
 838                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 839                         return;
 840                 }
 841
 842                 self::switchContact($cid);
 843
 844                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
 845                 if (!DBA::isResult($contact)) {
 846                         return;
 847                 }
 848
 849                 Contact::removeFollower($owner, $contact);
 850                 Logger::log('Undo following request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 851         }
 852
 853         /**
 854          * Switches a contact to AP if needed
 855          *
 856          * @param integer $cid Contact ID
 857          * @throws \Exception
 858          */
 859         private static function switchContact($cid)
 860         {
 861                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
 862                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
 863                         return;
 864                 }
 865
 866                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
 867                 Contact::updateFromProbe($cid);
 868         }
 869
 870         /**
 871          * Collects implicit mentions like:
 872          * - the author of the parent item
 873          * - all the mentioned conversants in the parent item
 874          *
 875          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
 876          * @return array
 877          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 878          */
 879         private static function getImplicitMentionList(array $parent)
 880         {
 881                 if (Config::get('system', 'disable_implicit_mentions')) {
 882                         return [];
 883                 }
 884
 885                 $parent_terms = Term::tagArrayFromItemId($parent['id'], [Term::MENTION, Term::IMPLICIT_MENTION]);
 886
 887                 $parent_author = Contact::getDetailsByURL($parent['author-link'], 0);
 888
 889                 $implicit_mentions = [];
 890                 if (empty($parent_author)) {
 891                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
 892                 } else {
 893                         $implicit_mentions[] = $parent_author['url'];
 894                         $implicit_mentions[] = $parent_author['nurl'];
 895                         $implicit_mentions[] = $parent_author['alias'];
 896                 }
 897
 898                 if (!empty($parent['alias'])) {
 899                         $implicit_mentions[] = $parent['alias'];
 900                 }
 901
 902                 foreach ($parent_terms as $term) {
 903                         $contact = Contact::getDetailsByURL($term['url'], 0);
 904                         if (!empty($contact)) {
 905                                 $implicit_mentions[] = $contact['url'];
 906                                 $implicit_mentions[] = $contact['nurl'];
 907                                 $implicit_mentions[] = $contact['alias'];
 908                         }
 909                 }
 910
 911                 return $implicit_mentions;
 912         }
 913
 914         /**
 915          * Strips from the body prepended implicit mentions
 916          *
 917          * @param string $body
 918          * @param array $potential_mentions
 919          * @return string
 920          */
 921         private static function removeImplicitMentionsFromBody($body, array $potential_mentions)
 922         {
 923                 if (Config::get('system', 'disable_implicit_mentions')) {
 924                         return $body;
 925                 }
 926
 927                 $kept_mentions = [];
 928
 929                 // Extract one prepended mention at a time from the body
 930                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
 931                         if (!in_array($matches[2], $potential_mentions)) {
 932                                 $kept_mentions[] = $matches[1];
 933                         }
 934
 935                         $body = $matches[3];
 936                 }
 937
 938                 // Re-appending the kept mentions to the body after extraction
 939                 $kept_mentions[] = $body;
 940
 941                 return implode('', $kept_mentions);
 942         }
 943
 944         private static function convertImplicitMentionsInTags($activity_tags, array $potential_mentions)
 945         {
 946                 if (Config::get('system', 'disable_implicit_mentions')) {
 947                         return $activity_tags;
 948                 }
 949
 950                 foreach ($activity_tags as $index => $tag) {
 951                         if (in_array($tag['href'], $potential_mentions)) {
 952                                 $activity_tags[$index]['name'] = preg_replace(
 953                                         '/' . preg_quote(Term::TAG_CHARACTER[Term::MENTION], '/') . '/',
 954                                         Term::TAG_CHARACTER[Term::IMPLICIT_MENTION],
 955                                         $activity_tags[$index]['name'],
 956                                         1
 957                                 );
 958                         }
 959                 }
 960
 961                 return $activity_tags;
 962         }
 963 }