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