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'], $receiver, true);
 418                         }
 419
 420                         if (empty($item['contact-id'])) {
 421                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
 422                         }
 423
 424                         if (($receiver != 0) && empty($item['contact-id'])) {
 425                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
 426                         }
 427
 428                         if (!empty($activity['directmessage'])) {
 429                                 self::postMail($activity, $item);
 430                                 continue;
 431                         }
 432
 433                         if (PConfig::get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 434                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 435
 436                                 if ($skip && (($activity['type'] == 'as:Announce') || $isForum)) {
 437                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 438                                 }
 439
 440                                 if ($skip) {
 441                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 442                                         continue;
 443                                 }
 444
 445                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 446                         }
 447
 448                         if ($activity['object_type'] == 'as:Event') {
 449                                 self::createEvent($activity, $item);
 450                         }
 451
 452                         $item_id = Item::insert($item);
 453                         if ($item_id) {
 454                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 455                         } else {
 456                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 457                         }
 458
 459                         if ($item['uid'] == 0) {
 460                                 $stored = $item_id;
 461                         }
 462                 }
 463
 464                 // Store send a follow request for every reshare - but only when the item had been stored
 465                 if ($stored && !$item['private'] && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 466                         $author = APContact::getByURL($item['owner-link'], false);
 467                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 468                         if ($author['type'] != 'Group') {
 469                                 Logger::log('Send follow request for ' . $item['uri'] . ' (' . $stored . ') to ' . $item['author-link'], Logger::DEBUG);
 470                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 471                         }
 472                 }
 473         }
 474
 475         /**
 476          * Creates an mail post
 477          *
 478          * @param array $activity Activity data
 479          * @param array $item     item array
 480          * @return int|bool New mail table row id or false on error
 481          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 482          */
 483         private static function postMail($activity, $item)
 484         {
 485                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 486                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 487                         return false;
 488                 }
 489
 490                 Logger::info('Direct Message', $item);
 491
 492                 $msg = [];
 493                 $msg['uid'] = $item['uid'];
 494
 495                 $msg['contact-id'] = $item['contact-id'];
 496
 497                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 498                 $msg['from-name'] = $contact['name'];
 499                 $msg['from-url'] = $contact['url'];
 500                 $msg['from-photo'] = $contact['photo'];
 501
 502                 $msg['uri'] = $item['uri'];
 503                 $msg['created'] = $item['created'];
 504
 505                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 506                 if (DBA::isResult($parent)) {
 507                         $msg['parent-uri'] = $parent['parent-uri'];
 508                         $msg['title'] = $parent['title'];
 509                 } else {
 510                         $msg['parent-uri'] = $item['thr-parent'];
 511
 512                         if (!empty($item['title'])) {
 513                                 $msg['title'] = $item['title'];
 514                         } elseif (!empty($item['content-warning'])) {
 515                                 $msg['title'] = $item['content-warning'];
 516                         } else {
 517                                 // Trying to generate a title out of the body
 518                                 $title = $item['body'];
 519
 520                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 521                                         $title = $matches[3];
 522                                 }
 523
 524                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, 2, true), 0));
 525
 526                                 if (strlen($title) > 20) {
 527                                         $title = substr($title, 0, 20) . '...';
 528                                 }
 529
 530                                 $msg['title'] = $title;
 531                         }
 532                 }
 533                 $msg['body'] = $item['body'];
 534
 535                 return Mail::insert($msg);
 536         }
 537
 538         /**
 539          * Fetches missing posts
 540          *
 541          * @param string $url message URL
 542          * @param array $child activity array with the child of this message
 543          * @return boolean success
 544          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 545          */
 546         public static function fetchMissingActivity($url, $child = [])
 547         {
 548                 if (!empty($child['receiver'])) {
 549                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 550                 } else {
 551                         $uid = 0;
 552                 }
 553
 554                 $object = ActivityPub::fetchContent($url, $uid);
 555                 if (empty($object)) {
 556                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 557                         return false;
 558                 }
 559
 560                 if (empty($object['id'])) {
 561                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 562                         return false;
 563                 }
 564
 565                 if (!empty($child['author'])) {
 566                         $actor = $child['author'];
 567                 } elseif (!empty($object['actor'])) {
 568                         $actor = $object['actor'];
 569                 } elseif (!empty($object['attributedTo'])) {
 570                         $actor = $object['attributedTo'];
 571                 } else {
 572                         // Shouldn't happen
 573                         $actor = '';
 574                 }
 575
 576                 if (!empty($object['published'])) {
 577                         $published = $object['published'];
 578                 } elseif (!empty($child['published'])) {
 579                         $published = $child['published'];
 580                 } else {
 581                         $published = DateTimeFormat::utcNow();
 582                 }
 583
 584                 $activity = [];
 585                 $activity['@context'] = $object['@context'];
 586                 unset($object['@context']);
 587                 $activity['id'] = $object['id'];
 588                 $activity['to'] = defaults($object, 'to', []);
 589                 $activity['cc'] = defaults($object, 'cc', []);
 590                 $activity['actor'] = $actor;
 591                 $activity['object'] = $object;
 592                 $activity['published'] = $published;
 593                 $activity['type'] = 'Create';
 594
 595                 $ldactivity = JsonLD::compact($activity);
 596
 597                 $ldactivity['thread-completion'] = true;
 598
 599                 ActivityPub\Receiver::processActivity($ldactivity);
 600                 Logger::log('Activity ' . $url . ' had been fetched and processed.');
 601
 602                 return true;
 603         }
 604
 605         /**
 606          * perform a "follow" request
 607          *
 608          * @param array $activity
 609          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 610          * @throws \ImagickException
 611          */
 612         public static function followUser($activity)
 613         {
 614                 $uid = User::getIdForURL($activity['object_id']);
 615                 if (empty($uid)) {
 616                         return;
 617                 }
 618
 619                 $owner = User::getOwnerDataById($uid);
 620
 621                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 622                 if (!empty($cid)) {
 623                         self::switchContact($cid);
 624                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 625                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 626                 } else {
 627                         $contact = [];
 628                 }
 629
 630                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 631                         'author-link' => $activity['actor']];
 632
 633                 $note = Strings::escapeTags(trim(defaults($activity, 'content', '')));
 634
 635                 // Ensure that the contact has got the right network type
 636                 self::switchContact($item['author-id']);
 637
 638                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 639                 if ($result === true) {
 640                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $item['author-id'], $owner['uid']);
 641                 }
 642
 643                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 644                 if (empty($cid)) {
 645                         return;
 646                 }
 647
 648                 if (empty($contact)) {
 649                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 650                 }
 651
 652                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 653         }
 654
 655         /**
 656          * Update the given profile
 657          *
 658          * @param array $activity
 659          * @throws \Exception
 660          */
 661         public static function updatePerson($activity)
 662         {
 663                 if (empty($activity['object_id'])) {
 664                         return;
 665                 }
 666
 667                 Logger::log('Updating profile for ' . $activity['object_id'], Logger::DEBUG);
 668                 Contact::updateFromProbeByURL($activity['object_id'], true);
 669         }
 670
 671         /**
 672          * Delete the given profile
 673          *
 674          * @param array $activity
 675          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 676          */
 677         public static function deletePerson($activity)
 678         {
 679                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 680                         Logger::log('Empty object id or actor.', Logger::DEBUG);
 681                         return;
 682                 }
 683
 684                 if ($activity['object_id'] != $activity['actor']) {
 685                         Logger::log('Object id does not match actor.', Logger::DEBUG);
 686                         return;
 687                 }
 688
 689                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 690                 while ($contact = DBA::fetch($contacts)) {
 691                         Contact::remove($contact['id']);
 692                 }
 693                 DBA::close($contacts);
 694
 695                 Logger::log('Deleted contact ' . $activity['object_id'], Logger::DEBUG);
 696         }
 697
 698         /**
 699          * Accept a follow request
 700          *
 701          * @param array $activity
 702          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 703          * @throws \ImagickException
 704          */
 705         public static function acceptFollowUser($activity)
 706         {
 707                 $uid = User::getIdForURL($activity['object_actor']);
 708                 if (empty($uid)) {
 709                         return;
 710                 }
 711
 712                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 713                 if (empty($cid)) {
 714                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 715                         return;
 716                 }
 717
 718                 self::switchContact($cid);
 719
 720                 $fields = ['pending' => false];
 721
 722                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 723                 if ($contact['rel'] == Contact::FOLLOWER) {
 724                         $fields['rel'] = Contact::FRIEND;
 725                 }
 726
 727                 $condition = ['id' => $cid];
 728                 DBA::update('contact', $fields, $condition);
 729                 Logger::log('Accept contact request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 730         }
 731
 732         /**
 733          * Reject a follow request
 734          *
 735          * @param array $activity
 736          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 737          * @throws \ImagickException
 738          */
 739         public static function rejectFollowUser($activity)
 740         {
 741                 $uid = User::getIdForURL($activity['object_actor']);
 742                 if (empty($uid)) {
 743                         return;
 744                 }
 745
 746                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 747                 if (empty($cid)) {
 748                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 749                         return;
 750                 }
 751
 752                 self::switchContact($cid);
 753
 754                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
 755                         Contact::remove($cid);
 756                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . ' - contact had been removed.', Logger::DEBUG);
 757                 } else {
 758                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . '.', Logger::DEBUG);
 759                 }
 760         }
 761
 762         /**
 763          * Undo activity like "like" or "dislike"
 764          *
 765          * @param array $activity
 766          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 767          * @throws \ImagickException
 768          */
 769         public static function undoActivity($activity)
 770         {
 771                 if (empty($activity['object_id'])) {
 772                         return;
 773                 }
 774
 775                 if (empty($activity['object_actor'])) {
 776                         return;
 777                 }
 778
 779                 $author_id = Contact::getIdForURL($activity['object_actor']);
 780                 if (empty($author_id)) {
 781                         return;
 782                 }
 783
 784                 Item::delete(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
 785         }
 786
 787         /**
 788          * Activity to remove a follower
 789          *
 790          * @param array $activity
 791          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 792          * @throws \ImagickException
 793          */
 794         public static function undoFollowUser($activity)
 795         {
 796                 $uid = User::getIdForURL($activity['object_object']);
 797                 if (empty($uid)) {
 798                         return;
 799                 }
 800
 801                 $owner = User::getOwnerDataById($uid);
 802
 803                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 804                 if (empty($cid)) {
 805                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 806                         return;
 807                 }
 808
 809                 self::switchContact($cid);
 810
 811                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
 812                 if (!DBA::isResult($contact)) {
 813                         return;
 814                 }
 815
 816                 Contact::removeFollower($owner, $contact);
 817                 Logger::log('Undo following request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 818         }
 819
 820         /**
 821          * Switches a contact to AP if needed
 822          *
 823          * @param integer $cid Contact ID
 824          * @throws \Exception
 825          */
 826         private static function switchContact($cid)
 827         {
 828                 $contact = DBA::selectFirst('contact', ['network'], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 829                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
 830                         return;
 831                 }
 832
 833                 Logger::log('Change existing contact ' . $cid . ' from ' . $contact['network'] . ' to ActivityPub.');
 834                 Contact::updateFromProbe($cid, Protocol::ACTIVITYPUB);
 835         }
 836
 837         /**
 838          * Collects implicit mentions like:
 839          * - the author of the parent item
 840          * - all the mentioned conversants in the parent item
 841          *
 842          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
 843          * @return array
 844          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 845          */
 846         private static function getImplicitMentionList(array $parent)
 847         {
 848                 if (Config::get('system', 'disable_implicit_mentions')) {
 849                         return [];
 850                 }
 851
 852                 $parent_terms = Term::tagArrayFromItemId($parent['id'], [Term::MENTION, Term::IMPLICIT_MENTION]);
 853
 854                 $parent_author = Contact::getDetailsByURL($parent['author-link'], 0);
 855
 856                 $implicit_mentions = [];
 857                 if (empty($parent_author)) {
 858                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
 859                 } else {
 860                         $implicit_mentions[] = $parent_author['url'];
 861                         $implicit_mentions[] = $parent_author['nurl'];
 862                         $implicit_mentions[] = $parent_author['alias'];
 863                 }
 864
 865                 if (!empty($parent['alias'])) {
 866                         $implicit_mentions[] = $parent['alias'];
 867                 }
 868
 869                 foreach ($parent_terms as $term) {
 870                         $contact = Contact::getDetailsByURL($term['url'], 0);
 871                         if (!empty($contact)) {
 872                                 $implicit_mentions[] = $contact['url'];
 873                                 $implicit_mentions[] = $contact['nurl'];
 874                                 $implicit_mentions[] = $contact['alias'];
 875                         }
 876                 }
 877
 878                 return $implicit_mentions;
 879         }
 880
 881         /**
 882          * Strips from the body prepended implicit mentions
 883          *
 884          * @param string $body
 885          * @param array $potential_mentions
 886          * @return string
 887          */
 888         private static function removeImplicitMentionsFromBody($body, array $potential_mentions)
 889         {
 890                 if (Config::get('system', 'disable_implicit_mentions')) {
 891                         return $body;
 892                 }
 893
 894                 $kept_mentions = [];
 895
 896                 // Extract one prepended mention at a time from the body
 897                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
 898                         if (!in_array($matches[2], $potential_mentions) ) {
 899                                 $kept_mentions[] = $matches[1];
 900                         }
 901
 902                         $body = $matches[3];
 903                 }
 904
 905                 // Re-appending the kept mentions to the body after extraction
 906                 $kept_mentions[] = $body;
 907
 908                 return implode('', $kept_mentions);
 909         }
 910
 911         private static function convertImplicitMentionsInTags($activity_tags, array $potential_mentions)
 912         {
 913                 if (Config::get('system', 'disable_implicit_mentions')) {
 914                         return $activity_tags;
 915                 }
 916
 917                 foreach ($activity_tags as $index => $tag) {
 918                         if (in_array($tag['href'], $potential_mentions)) {
 919                                 $activity_tags[$index]['name'] = preg_replace(
 920                                         '/' . preg_quote(Term::TAG_CHARACTER[Term::MENTION], '/') . '/',
 921                                         Term::TAG_CHARACTER[Term::IMPLICIT_MENTION],
 922                                         $activity_tags[$index]['name'],
 923                                         1
 924                                 );
 925                         }
 926                 }
 927
 928                 return $activity_tags;
 929         }
 930 }