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