src/Protocol/ActivityPub/Processor.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Text\BBCode;
  25 use Friendica\Content\Text\HTML;
  26 use Friendica\Core\Logger;
  27 use Friendica\Core\Protocol;
  28 use Friendica\Database\DBA;
  29 use Friendica\DI;
  30 use Friendica\Model\APContact;
  31 use Friendica\Model\Contact;
  32 use Friendica\Model\Conversation;
  33 use Friendica\Model\Event;
  34 use Friendica\Model\Item;
  35 use Friendica\Model\ItemURI;
  36 use Friendica\Model\Mail;
  37 use Friendica\Model\Tag;
  38 use Friendica\Model\User;
  39 use Friendica\Protocol\Activity;
  40 use Friendica\Protocol\ActivityPub;
  41 use Friendica\Util\DateTimeFormat;
  42 use Friendica\Util\JsonLD;
  43 use Friendica\Util\Strings;
  44
  45 /**
  46  * ActivityPub Processor Protocol class
  47  */
  48 class Processor
  49 {
  50         /**
  51          * Converts mentions from Pleroma into the Friendica format
  52          *
  53          * @param string $body
  54          *
  55          * @return string converted body
  56          */
  57         private static function convertMentions($body)
  58         {
  59                 $URLSearchString = "^\[\]";
  60                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
  61
  62                 return $body;
  63         }
  64
  65         /**
  66          * Replaces emojis in the body
  67          *
  68          * @param array $emojis
  69          * @param string $body
  70          *
  71          * @return string with replaced emojis
  72          */
  73         private static function replaceEmojis($body, array $emojis)
  74         {
  75                 foreach ($emojis as $emoji) {
  76                         $replace = '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
  77                         $body = str_replace($emoji['name'], $replace, $body);
  78                 }
  79                 return $body;
  80         }
  81
  82         /**
  83          * Constructs a string with tags for a given tag array
  84          *
  85          * @param array   $tags
  86          * @param boolean $sensitive
  87          * @return string with tags
  88          */
  89         private static function constructTagString(array $tags = null, $sensitive = false)
  90         {
  91                 if (empty($tags)) {
  92                         return '';
  93                 }
  94
  95                 $tag_text = '';
  96                 foreach ($tags as $tag) {
  97                         if (in_array($tag['type'] ?? '', ['Mention', 'Hashtag'])) {
  98                                 if (!empty($tag_text)) {
  99                                         $tag_text .= ',';
 100                                 }
 101
 102                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
 103                         }
 104                 }
 105
 106                 /// @todo add nsfw for $sensitive
 107
 108                 return $tag_text;
 109         }
 110
 111         /**
 112          * Add attachment data to the item array
 113          *
 114          * @param array   $activity
 115          * @param array   $item
 116          *
 117          * @return array array
 118          */
 119         private static function constructAttachList($activity, $item)
 120         {
 121                 if (empty($activity['attachments'])) {
 122                         return $item;
 123                 }
 124
 125                 foreach ($activity['attachments'] as $attach) {
 126                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 127                         if ($filetype == 'image') {
 128                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 129                                         continue;
 130                                 }
 131
 132                                 if (empty($attach['name'])) {
 133                                         $item['body'] .= "\n[img]" . $attach['url'] . '[/img]';
 134                                 } else {
 135                                         $item['body'] .= "\n[img=" . $attach['url'] . ']' . $attach['name'] . '[/img]';
 136                                 }
 137                         } elseif ($filetype == 'audio') {
 138                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 139                                         continue;
 140                                 }
 141
 142                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 143                         } elseif ($filetype == 'video') {
 144                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 145                                         continue;
 146                                 }
 147
 148                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 149                         } else {
 150                                 if (!empty($item["attach"])) {
 151                                         $item["attach"] .= ',';
 152                                 } else {
 153                                         $item["attach"] = '';
 154                                 }
 155                                 if (!isset($attach['length'])) {
 156                                         $attach['length'] = "0";
 157                                 }
 158                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.($attach['name'] ?? '') .'"[/attach]';
 159                         }
 160                 }
 161
 162                 return $item;
 163         }
 164
 165         /**
 166          * Updates a message
 167          *
 168          * @param array $activity Activity array
 169          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 170          */
 171         public static function updateItem($activity)
 172         {
 173                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 174                 if (!DBA::isResult($item)) {
 175                         Logger::warning('No existing item, item will be created', ['uri' => $activity['id']]);
 176                         self::createItem($activity);
 177                         return;
 178                 }
 179
 180                 $item['changed'] = DateTimeFormat::utcNow();
 181                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 182
 183                 $item = self::processContent($activity, $item);
 184                 if (empty($item)) {
 185                         return;
 186                 }
 187
 188                 Item::update($item, ['uri' => $activity['id']]);
 189         }
 190
 191         /**
 192          * Prepares data for a message
 193          *
 194          * @param array $activity Activity array
 195          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 196          * @throws \ImagickException
 197          */
 198         public static function createItem($activity)
 199         {
 200                 $item = [];
 201                 $item['verb'] = Activity::POST;
 202                 $item['thr-parent'] = $activity['reply-to-id'];
 203
 204                 if ($activity['reply-to-id'] == $activity['id']) {
 205                         $item['gravity'] = GRAVITY_PARENT;
 206                         $item['object-type'] = Activity\ObjectType::NOTE;
 207                 } else {
 208                         $item['gravity'] = GRAVITY_COMMENT;
 209                         $item['object-type'] = Activity\ObjectType::COMMENT;
 210
 211                         // Ensure that the comment reaches all receivers of the referring post
 212                         $activity['receiver'] = self::addReceivers($activity);
 213                 }
 214
 215                 if (empty($activity['directmessage']) && ($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
 216                         Logger::notice('Parent not found. Try to refetch it.', ['parent' => $activity['reply-to-id']]);
 217                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
 218                 }
 219
 220                 $item['diaspora_signed_text'] = $activity['diaspora:comment'] ?? '';
 221
 222                 self::postItem($activity, $item);
 223         }
 224
 225         /**
 226          * Delete items
 227          *
 228          * @param array $activity
 229          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 230          * @throws \ImagickException
 231          */
 232         public static function deleteItem($activity)
 233         {
 234                 $owner = Contact::getIdForURL($activity['actor']);
 235
 236                 Logger::log('Deleting item ' . $activity['object_id'] . ' from ' . $owner, Logger::DEBUG);
 237                 Item::markForDeletion(['uri' => $activity['object_id'], 'owner-id' => $owner]);
 238         }
 239
 240         /**
 241          * Prepare the item array for an activity
 242          *
 243          * @param array $activity Activity array
 244          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 245          * @throws \ImagickException
 246          */
 247         public static function addTag($activity)
 248         {
 249                 if (empty($activity['object_content']) || empty($activity['object_id'])) {
 250                         return;
 251                 }
 252
 253                 foreach ($activity['receiver'] as $receiver) {
 254                         $item = Item::selectFirst(['id', 'uri-id', 'tag', 'origin', 'author-link'], ['uri' => $activity['target_id'], 'uid' => $receiver]);
 255                         if (!DBA::isResult($item)) {
 256                                 // We don't fetch missing content for this purpose
 257                                 continue;
 258                         }
 259
 260                         if (($item['author-link'] != $activity['actor']) && !$item['origin']) {
 261                                 Logger::info('Not origin, not from the author, skipping update', ['id' => $item['id'], 'author' => $item['author-link'], 'actor' => $activity['actor']]);
 262                                 continue;
 263                         }
 264
 265                         Tag::store($item['uri-id'], Tag::HASHTAG, $activity['object_content'], $activity['object_id']);
 266
 267                         // To-Do:
 268                         // - Check if "blocktag" is set
 269                         // - Check if actor is a contact
 270
 271                         if (!stristr($item['tag'], trim($activity['object_content']))) {
 272                                 $tag = $item['tag'] . (strlen($item['tag']) ? ',' : '') . '#[url=' . $activity['object_id'] . ']'. $activity['object_content'] . '[/url]';
 273                                 Item::update(['tag' => $tag], ['id' => $item['id']]);
 274                                 Logger::info('Tagged item', ['id' => $item['id'], 'tag' => $activity['object_content'], 'uri' => $activity['target_id'], 'actor' => $activity['actor']]);
 275                         }
 276                 }
 277         }
 278
 279         /**
 280          * Add users to the receiver list of the given public activity.
 281          * This is used to ensure that the activity will be stored in every thread.
 282          *
 283          * @param array $activity Activity array
 284          * @return array Modified receiver list
 285          */
 286         private static function addReceivers(array $activity)
 287         {
 288                 if (!in_array(0, $activity['receiver'])) {
 289                         // Private activities will not be modified
 290                         return $activity['receiver'];
 291                 }
 292
 293                 // Add all owners of the referring item to the receivers
 294                 $original = $receivers = $activity['receiver'];
 295                 $items = Item::select(['uid'], ['uri' => $activity['object_id']]);
 296                 while ($item = DBA::fetch($items)) {
 297                         $receivers['uid:' . $item['uid']] = $item['uid'];
 298                 }
 299                 DBA::close($items);
 300
 301                 if (count($original) != count($receivers)) {
 302                         Logger::info('Improved data', ['id' => $activity['id'], 'object' => $activity['object_id'], 'original' => $original, 'improved' => $receivers]);
 303                 }
 304
 305                 return $receivers;
 306         }
 307
 308         /**
 309          * Prepare the item array for an activity
 310          *
 311          * @param array  $activity Activity array
 312          * @param string $verb     Activity verb
 313          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 314          * @throws \ImagickException
 315          */
 316         public static function createActivity($activity, $verb)
 317         {
 318                 $item = [];
 319                 $item['verb'] = $verb;
 320                 $item['thr-parent'] = $activity['object_id'];
 321                 $item['gravity'] = GRAVITY_ACTIVITY;
 322                 $item['object-type'] = Activity\ObjectType::NOTE;
 323
 324                 $item['diaspora_signed_text'] = $activity['diaspora:like'] ?? '';
 325
 326                 $activity['receiver'] = self::addReceivers($activity);
 327
 328                 self::postItem($activity, $item);
 329         }
 330
 331         /**
 332          * Create an event
 333          *
 334          * @param array $activity Activity array
 335          * @param array $item
 336          * @throws \Exception
 337          */
 338         public static function createEvent($activity, $item)
 339         {
 340                 $event['summary']  = HTML::toBBCode($activity['name']);
 341                 $event['desc']     = HTML::toBBCode($activity['content']);
 342                 $event['start']    = $activity['start-time'];
 343                 $event['finish']   = $activity['end-time'];
 344                 $event['nofinish'] = empty($event['finish']);
 345                 $event['location'] = $activity['location'];
 346                 $event['adjust']   = true;
 347                 $event['cid']      = $item['contact-id'];
 348                 $event['uid']      = $item['uid'];
 349                 $event['uri']      = $item['uri'];
 350                 $event['edited']   = $item['edited'];
 351                 $event['private']  = $item['private'];
 352                 $event['guid']     = $item['guid'];
 353                 $event['plink']    = $item['plink'];
 354
 355                 $condition = ['uri' => $item['uri'], 'uid' => $item['uid']];
 356                 $ev = DBA::selectFirst('event', ['id'], $condition);
 357                 if (DBA::isResult($ev)) {
 358                         $event['id'] = $ev['id'];
 359                 }
 360
 361                 $event_id = Event::store($event);
 362                 Logger::log('Event '.$event_id.' was stored', Logger::DEBUG);
 363         }
 364
 365         /**
 366          * Process the content
 367          *
 368          * @param array $activity Activity array
 369          * @param array $item
 370          * @return array|bool Returns the item array or false if there was an unexpected occurrence
 371          * @throws \Exception
 372          */
 373         private static function processContent($activity, $item)
 374         {
 375                 $item['title'] = HTML::toBBCode($activity['name']);
 376
 377                 if (!empty($activity['source'])) {
 378                         $item['body'] = $activity['source'];
 379                 } else {
 380                         $content = HTML::toBBCode($activity['content']);
 381
 382                         if (!empty($activity['emojis'])) {
 383                                 $content = self::replaceEmojis($content, $activity['emojis']);
 384                         }
 385
 386                         $content = self::convertMentions($content);
 387
 388                         if (empty($activity['directmessage']) && ($item['thr-parent'] != $item['uri']) && ($item['gravity'] == GRAVITY_COMMENT)) {
 389                                 $item_private = !in_array(0, $activity['item_receiver']);
 390                                 $parent = Item::selectFirst(['id', 'private', 'author-link', 'alias'], ['uri' => $item['thr-parent']]);
 391                                 if (!DBA::isResult($parent)) {
 392                                         Logger::warning('Unknown parent item.', ['uri' => $item['thr-parent']]);
 393                                         return false;
 394                                 }
 395                                 if ($item_private && ($parent['private'] == Item::PRIVATE)) {
 396                                         Logger::warning('Item is private but the parent is not. Dropping.', ['item-uri' => $item['uri'], 'thr-parent' => $item['thr-parent']]);
 397                                         return false;
 398                                 }
 399
 400                                 $potential_implicit_mentions = self::getImplicitMentionList($parent);
 401                                 $content = self::removeImplicitMentionsFromBody($content, $potential_implicit_mentions);
 402                                 $activity['tags'] = self::convertImplicitMentionsInTags($activity['tags'], $potential_implicit_mentions);
 403                         }
 404                         $item['content-warning'] = HTML::toBBCode($activity['summary']);
 405                         $item['body'] = $content;
 406                 }
 407
 408                 $item['tag'] = self::constructTagString($activity['tags'], $activity['sensitive']);
 409
 410                 self::storeFromBody($item);
 411                 self::storeTags($item['uri-id'], $activity['tags']);
 412
 413                 $item['location'] = $activity['location'];
 414
 415                 if (!empty($item['latitude']) && !empty($item['longitude'])) {
 416                         $item['coord'] = $item['latitude'] . ' ' . $item['longitude'];
 417                 }
 418
 419                 $item['app'] = $activity['generator'];
 420
 421                 return $item;
 422         }
 423
 424         /**
 425          * Store hashtags and mentions
 426          *
 427          * @param array $item
 428          */
 429         private static function storeFromBody(array $item)
 430         {
 431                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 432                 DBA::delete('post-tag', ['uri-id' => $item['uri-id']]);
 433
 434                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 435         }
 436
 437         /**
 438          * Generate a GUID out of an URL
 439          *
 440          * @param string $url message URL
 441          * @return string with GUID
 442          */
 443         private static function getGUIDByURL(string $url)
 444         {
 445                 $parsed = parse_url($url);
 446
 447                 $host_hash = hash('crc32', $parsed['host']);
 448
 449                 unset($parsed["scheme"]);
 450                 unset($parsed["host"]);
 451
 452                 $path = implode("/", $parsed);
 453
 454                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 455         }
 456
 457         /**
 458          * Creates an item post
 459          *
 460          * @param array $activity Activity data
 461          * @param array $item     item array
 462          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 463          * @throws \ImagickException
 464          */
 465         private static function postItem($activity, $item)
 466         {
 467                 /// @todo What to do with $activity['context']?
 468                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 469                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 470                         return;
 471                 }
 472
 473                 $item['network'] = Protocol::ACTIVITYPUB;
 474                 $item['author-link'] = $activity['author'];
 475                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
 476                 $item['owner-link'] = $activity['actor'];
 477                 $item['owner-id'] = Contact::getIdForURL($activity['actor'], 0, true);
 478
 479                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 480                         $item['private'] = Item::UNLISTED;
 481                 } elseif (in_array(0, $activity['receiver'])) {
 482                         $item['private'] = Item::PUBLIC;
 483                 } else {
 484                         $item['private'] = Item::PRIVATE;
 485                 }
 486
 487                 if (!empty($activity['raw'])) {
 488                         $item['source'] = $activity['raw'];
 489                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 490                         $item['conversation-href'] = $activity['context'] ?? '';
 491                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 492
 493                         if (isset($activity['push'])) {
 494                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 495                         }
 496                 }
 497
 498                 $isForum = false;
 499
 500                 if (!empty($activity['thread-completion'])) {
 501                         // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 502                         $item['causer-link'] = $item['owner-link'];
 503                         $item['causer-id'] = $item['owner-id'];
 504
 505                         Logger::info('Ignoring actor because of thread completion.', ['actor' => $item['owner-link']]);
 506                         $item['owner-link'] = $item['author-link'];
 507                         $item['owner-id'] = $item['author-id'];
 508                 } else {
 509                         $actor = APContact::getByURL($item['owner-link'], false);
 510                         $isForum = ($actor['type'] == 'Group');
 511                 }
 512
 513                 $item['uri'] = $activity['id'];
 514
 515                 $item['created'] = DateTimeFormat::utc($activity['published']);
 516                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 517                 $item['guid'] = $activity['diaspora:guid'] ?: $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 518
 519                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 520
 521                 $item = self::processContent($activity, $item);
 522                 if (empty($item)) {
 523                         return;
 524                 }
 525
 526                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 527
 528                 $item = self::constructAttachList($activity, $item);
 529
 530                 $stored = false;
 531
 532                 foreach ($activity['receiver'] as $receiver) {
 533                         if ($receiver == -1) {
 534                                 continue;
 535                         }
 536
 537                         $item['uid'] = $receiver;
 538
 539                         if ($isForum) {
 540                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver, true);
 541                         } else {
 542                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
 543                         }
 544
 545                         if (($receiver != 0) && empty($item['contact-id'])) {
 546                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
 547                         }
 548
 549                         if (!empty($activity['directmessage'])) {
 550                                 self::postMail($activity, $item);
 551                                 continue;
 552                         }
 553
 554                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 555                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 556
 557                                 if ($skip && (($activity['type'] == 'as:Announce') || $isForum)) {
 558                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 559                                 }
 560
 561                                 if ($skip) {
 562                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 563                                         continue;
 564                                 }
 565
 566                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 567                         }
 568
 569                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 570                                 self::createEvent($activity, $item);
 571                         }
 572
 573                         $item_id = Item::insert($item);
 574                         if ($item_id) {
 575                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 576                         } else {
 577                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 578                         }
 579
 580                         if ($item['uid'] == 0) {
 581                                 $stored = $item_id;
 582                         }
 583                 }
 584
 585                 // Store send a follow request for every reshare - but only when the item had been stored
 586                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 587                         $author = APContact::getByURL($item['owner-link'], false);
 588                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 589                         if ($author['type'] != 'Group') {
 590                                 Logger::log('Send follow request for ' . $item['uri'] . ' (' . $stored . ') to ' . $item['author-link'], Logger::DEBUG);
 591                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 592                         }
 593                 }
 594         }
 595
 596         /**
 597          * Store tags and mentions into the tag table
 598          *
 599          * @param integer $uriid
 600          * @param array $tags
 601          */
 602         private static function storeTags(int $uriid, array $tags = null)
 603         {
 604                 foreach ($tags as $tag) {
 605                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 606                                 continue;
 607                         }
 608
 609                         $hash = substr($tag['name'], 0, 1);
 610
 611                         if ($tag['type'] == 'Mention') {
 612                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 613                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 614                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 615                                         $tag['name'] = substr($tag['name'], 1);
 616                                 }
 617                                 $type = Tag::IMPLICIT_MENTION;
 618
 619                                 if (!empty($tag['href'])) {
 620                                         $apcontact = APContact::getByURL($tag['href']);
 621                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 622                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 623                                         }
 624                                 }
 625                         } elseif ($tag['type'] == 'Hashtag') {
 626                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 627                                         $tag['name'] = substr($tag['name'], 1);
 628                                 }
 629                                 $type = Tag::HASHTAG;
 630                         }
 631
 632                         if (empty($tag['name'])) {
 633                                 continue;
 634                         }
 635
 636                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 637                 }
 638         }
 639
 640         /**
 641          * Creates an mail post
 642          *
 643          * @param array $activity Activity data
 644          * @param array $item     item array
 645          * @return int|bool New mail table row id or false on error
 646          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 647          */
 648         private static function postMail($activity, $item)
 649         {
 650                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 651                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 652                         return false;
 653                 }
 654
 655                 Logger::info('Direct Message', $item);
 656
 657                 $msg = [];
 658                 $msg['uid'] = $item['uid'];
 659
 660                 $msg['contact-id'] = $item['contact-id'];
 661
 662                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 663                 $msg['from-name'] = $contact['name'];
 664                 $msg['from-url'] = $contact['url'];
 665                 $msg['from-photo'] = $contact['photo'];
 666
 667                 $msg['uri'] = $item['uri'];
 668                 $msg['created'] = $item['created'];
 669
 670                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 671                 if (DBA::isResult($parent)) {
 672                         $msg['parent-uri'] = $parent['parent-uri'];
 673                         $msg['title'] = $parent['title'];
 674                 } else {
 675                         $msg['parent-uri'] = $item['thr-parent'];
 676
 677                         if (!empty($item['title'])) {
 678                                 $msg['title'] = $item['title'];
 679                         } elseif (!empty($item['content-warning'])) {
 680                                 $msg['title'] = $item['content-warning'];
 681                         } else {
 682                                 // Trying to generate a title out of the body
 683                                 $title = $item['body'];
 684
 685                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 686                                         $title = $matches[3];
 687                                 }
 688
 689                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, 2, true), 0));
 690
 691                                 if (strlen($title) > 20) {
 692                                         $title = substr($title, 0, 20) . '...';
 693                                 }
 694
 695                                 $msg['title'] = $title;
 696                         }
 697                 }
 698                 $msg['body'] = $item['body'];
 699
 700                 return Mail::insert($msg);
 701         }
 702
 703         /**
 704          * Fetches missing posts
 705          *
 706          * @param string $url message URL
 707          * @param array $child activity array with the child of this message
 708          * @return string fetched message URL
 709          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 710          */
 711         public static function fetchMissingActivity($url, $child = [])
 712         {
 713                 if (!empty($child['receiver'])) {
 714                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 715                 } else {
 716                         $uid = 0;
 717                 }
 718
 719                 $object = ActivityPub::fetchContent($url, $uid);
 720                 if (empty($object)) {
 721                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 722                         return '';
 723                 }
 724
 725                 if (empty($object['id'])) {
 726                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 727                         return '';
 728                 }
 729
 730                 if (!empty($child['author'])) {
 731                         $actor = $child['author'];
 732                 } elseif (!empty($object['actor'])) {
 733                         $actor = $object['actor'];
 734                 } elseif (!empty($object['attributedTo'])) {
 735                         $actor = $object['attributedTo'];
 736                 } else {
 737                         // Shouldn't happen
 738                         $actor = '';
 739                 }
 740
 741                 if (!empty($object['published'])) {
 742                         $published = $object['published'];
 743                 } elseif (!empty($child['published'])) {
 744                         $published = $child['published'];
 745                 } else {
 746                         $published = DateTimeFormat::utcNow();
 747                 }
 748
 749                 $activity = [];
 750                 $activity['@context'] = $object['@context'];
 751                 unset($object['@context']);
 752                 $activity['id'] = $object['id'];
 753                 $activity['to'] = $object['to'] ?? [];
 754                 $activity['cc'] = $object['cc'] ?? [];
 755                 $activity['actor'] = $actor;
 756                 $activity['object'] = $object;
 757                 $activity['published'] = $published;
 758                 $activity['type'] = 'Create';
 759
 760                 $ldactivity = JsonLD::compact($activity);
 761
 762                 $ldactivity['thread-completion'] = true;
 763
 764                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity));
 765
 766                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 767
 768                 return $activity['id'];
 769         }
 770
 771         /**
 772          * perform a "follow" request
 773          *
 774          * @param array $activity
 775          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 776          * @throws \ImagickException
 777          */
 778         public static function followUser($activity)
 779         {
 780                 $uid = User::getIdForURL($activity['object_id']);
 781                 if (empty($uid)) {
 782                         return;
 783                 }
 784
 785                 $owner = User::getOwnerDataById($uid);
 786
 787                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 788                 if (!empty($cid)) {
 789                         self::switchContact($cid);
 790                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 791                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 792                 } else {
 793                         $contact = [];
 794                 }
 795
 796                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 797                         'author-link' => $activity['actor']];
 798
 799                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 800
 801                 // Ensure that the contact has got the right network type
 802                 self::switchContact($item['author-id']);
 803
 804                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 805                 if ($result === true) {
 806                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $item['author-id'], $owner['uid']);
 807                 }
 808
 809                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 810                 if (empty($cid)) {
 811                         return;
 812                 }
 813
 814                 if (empty($contact)) {
 815                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 816                 }
 817
 818                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 819         }
 820
 821         /**
 822          * Update the given profile
 823          *
 824          * @param array $activity
 825          * @throws \Exception
 826          */
 827         public static function updatePerson($activity)
 828         {
 829                 if (empty($activity['object_id'])) {
 830                         return;
 831                 }
 832
 833                 Logger::log('Updating profile for ' . $activity['object_id'], Logger::DEBUG);
 834                 Contact::updateFromProbeByURL($activity['object_id'], true);
 835         }
 836
 837         /**
 838          * Delete the given profile
 839          *
 840          * @param array $activity
 841          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 842          */
 843         public static function deletePerson($activity)
 844         {
 845                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 846                         Logger::log('Empty object id or actor.', Logger::DEBUG);
 847                         return;
 848                 }
 849
 850                 if ($activity['object_id'] != $activity['actor']) {
 851                         Logger::log('Object id does not match actor.', Logger::DEBUG);
 852                         return;
 853                 }
 854
 855                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 856                 while ($contact = DBA::fetch($contacts)) {
 857                         Contact::remove($contact['id']);
 858                 }
 859                 DBA::close($contacts);
 860
 861                 Logger::log('Deleted contact ' . $activity['object_id'], Logger::DEBUG);
 862         }
 863
 864         /**
 865          * Accept a follow request
 866          *
 867          * @param array $activity
 868          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 869          * @throws \ImagickException
 870          */
 871         public static function acceptFollowUser($activity)
 872         {
 873                 $uid = User::getIdForURL($activity['object_actor']);
 874                 if (empty($uid)) {
 875                         return;
 876                 }
 877
 878                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 879                 if (empty($cid)) {
 880                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 881                         return;
 882                 }
 883
 884                 self::switchContact($cid);
 885
 886                 $fields = ['pending' => false];
 887
 888                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 889                 if ($contact['rel'] == Contact::FOLLOWER) {
 890                         $fields['rel'] = Contact::FRIEND;
 891                 }
 892
 893                 $condition = ['id' => $cid];
 894                 DBA::update('contact', $fields, $condition);
 895                 Logger::log('Accept contact request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 896         }
 897
 898         /**
 899          * Reject a follow request
 900          *
 901          * @param array $activity
 902          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 903          * @throws \ImagickException
 904          */
 905         public static function rejectFollowUser($activity)
 906         {
 907                 $uid = User::getIdForURL($activity['object_actor']);
 908                 if (empty($uid)) {
 909                         return;
 910                 }
 911
 912                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 913                 if (empty($cid)) {
 914                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 915                         return;
 916                 }
 917
 918                 self::switchContact($cid);
 919
 920                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
 921                         Contact::remove($cid);
 922                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . ' - contact had been removed.', Logger::DEBUG);
 923                 } else {
 924                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . '.', Logger::DEBUG);
 925                 }
 926         }
 927
 928         /**
 929          * Undo activity like "like" or "dislike"
 930          *
 931          * @param array $activity
 932          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 933          * @throws \ImagickException
 934          */
 935         public static function undoActivity($activity)
 936         {
 937                 if (empty($activity['object_id'])) {
 938                         return;
 939                 }
 940
 941                 if (empty($activity['object_actor'])) {
 942                         return;
 943                 }
 944
 945                 $author_id = Contact::getIdForURL($activity['object_actor']);
 946                 if (empty($author_id)) {
 947                         return;
 948                 }
 949
 950                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
 951         }
 952
 953         /**
 954          * Activity to remove a follower
 955          *
 956          * @param array $activity
 957          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 958          * @throws \ImagickException
 959          */
 960         public static function undoFollowUser($activity)
 961         {
 962                 $uid = User::getIdForURL($activity['object_object']);
 963                 if (empty($uid)) {
 964                         return;
 965                 }
 966
 967                 $owner = User::getOwnerDataById($uid);
 968
 969                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 970                 if (empty($cid)) {
 971                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 972                         return;
 973                 }
 974
 975                 self::switchContact($cid);
 976
 977                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
 978                 if (!DBA::isResult($contact)) {
 979                         return;
 980                 }
 981
 982                 Contact::removeFollower($owner, $contact);
 983                 Logger::log('Undo following request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 984         }
 985
 986         /**
 987          * Switches a contact to AP if needed
 988          *
 989          * @param integer $cid Contact ID
 990          * @throws \Exception
 991          */
 992         private static function switchContact($cid)
 993         {
 994                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
 995                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
 996                         return;
 997                 }
 998
 999                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
1000                 Contact::updateFromProbe($cid);
1001         }
1002
1003         /**
1004          * Collects implicit mentions like:
1005          * - the author of the parent item
1006          * - all the mentioned conversants in the parent item
1007          *
1008          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1009          * @return array
1010          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1011          */
1012         private static function getImplicitMentionList(array $parent)
1013         {
1014                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1015                         return [];
1016                 }
1017
1018                 $parent_terms = Tag::ArrayFromURIId($parent['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1019
1020                 $parent_author = Contact::getDetailsByURL($parent['author-link'], 0);
1021
1022                 $implicit_mentions = [];
1023                 if (empty($parent_author)) {
1024                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1025                 } else {
1026                         $implicit_mentions[] = $parent_author['url'];
1027                         $implicit_mentions[] = $parent_author['nurl'];
1028                         $implicit_mentions[] = $parent_author['alias'];
1029                 }
1030
1031                 if (!empty($parent['alias'])) {
1032                         $implicit_mentions[] = $parent['alias'];
1033                 }
1034
1035                 foreach ($parent_terms as $term) {
1036                         $contact = Contact::getDetailsByURL($term['url'], 0);
1037                         if (!empty($contact)) {
1038                                 $implicit_mentions[] = $contact['url'];
1039                                 $implicit_mentions[] = $contact['nurl'];
1040                                 $implicit_mentions[] = $contact['alias'];
1041                         }
1042                 }
1043
1044                 return $implicit_mentions;
1045         }
1046
1047         /**
1048          * Strips from the body prepended implicit mentions
1049          *
1050          * @param string $body
1051          * @param array $potential_mentions
1052          * @return string
1053          */
1054         private static function removeImplicitMentionsFromBody($body, array $potential_mentions)
1055         {
1056                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1057                         return $body;
1058                 }
1059
1060                 $kept_mentions = [];
1061
1062                 // Extract one prepended mention at a time from the body
1063                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1064                         if (!in_array($matches[2], $potential_mentions)) {
1065                                 $kept_mentions[] = $matches[1];
1066                         }
1067
1068                         $body = $matches[3];
1069                 }
1070
1071                 // Re-appending the kept mentions to the body after extraction
1072                 $kept_mentions[] = $body;
1073
1074                 return implode('', $kept_mentions);
1075         }
1076
1077         private static function convertImplicitMentionsInTags($activity_tags, array $potential_mentions)
1078         {
1079                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1080                         return $activity_tags;
1081                 }
1082
1083                 foreach ($activity_tags as $index => $tag) {
1084                         if (in_array($tag['href'], $potential_mentions)) {
1085                                 $activity_tags[$index]['name'] = preg_replace(
1086                                         '/' . preg_quote(Tag::TAG_CHARACTER[Tag::MENTION], '/') . '/',
1087                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION],
1088                                         $activity_tags[$index]['name'],
1089                                         1
1090                                 );
1091                         }
1092                 }
1093
1094                 return $activity_tags;
1095         }
1096 }