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\Term;
  39 use Friendica\Model\User;
  40 use Friendica\Protocol\Activity;
  41 use Friendica\Protocol\ActivityPub;
  42 use Friendica\Util\DateTimeFormat;
  43 use Friendica\Util\JsonLD;
  44 use Friendica\Util\Strings;
  45
  46 /**
  47  * ActivityPub Processor Protocol class
  48  */
  49 class Processor
  50 {
  51         /**
  52          * Converts mentions from Pleroma into the Friendica format
  53          *
  54          * @param string $body
  55          *
  56          * @return string converted body
  57          */
  58         private static function convertMentions($body)
  59         {
  60                 $URLSearchString = "^\[\]";
  61                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
  62
  63                 return $body;
  64         }
  65
  66         /**
  67          * Replaces emojis in the body
  68          *
  69          * @param array $emojis
  70          * @param string $body
  71          *
  72          * @return string with replaced emojis
  73          */
  74         private static function replaceEmojis($body, array $emojis)
  75         {
  76                 foreach ($emojis as $emoji) {
  77                         $replace = '[class=emoji mastodon][img=' . $emoji['href'] . ']' . $emoji['name'] . '[/img][/class]';
  78                         $body = str_replace($emoji['name'], $replace, $body);
  79                 }
  80                 return $body;
  81         }
  82
  83         /**
  84          * Constructs a string with tags for a given tag array
  85          *
  86          * @param array   $tags
  87          * @param boolean $sensitive
  88          * @return string with tags
  89          */
  90         private static function constructTagString(array $tags = null, $sensitive = false)
  91         {
  92                 if (empty($tags)) {
  93                         return '';
  94                 }
  95
  96                 $tag_text = '';
  97                 foreach ($tags as $tag) {
  98                         if (in_array($tag['type'] ?? '', ['Mention', 'Hashtag'])) {
  99                                 if (!empty($tag_text)) {
 100                                         $tag_text .= ',';
 101                                 }
 102
 103                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
 104                         }
 105                 }
 106
 107                 /// @todo add nsfw for $sensitive
 108
 109                 return $tag_text;
 110         }
 111
 112         /**
 113          * Add attachment data to the item array
 114          *
 115          * @param array   $activity
 116          * @param array   $item
 117          *
 118          * @return array array
 119          */
 120         private static function constructAttachList($activity, $item)
 121         {
 122                 if (empty($activity['attachments'])) {
 123                         return $item;
 124                 }
 125
 126                 foreach ($activity['attachments'] as $attach) {
 127                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
 128                         if ($filetype == 'image') {
 129                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 130                                         continue;
 131                                 }
 132
 133                                 if (empty($attach['name'])) {
 134                                         $item['body'] .= "\n[img]" . $attach['url'] . '[/img]';
 135                                 } else {
 136                                         $item['body'] .= "\n[img=" . $attach['url'] . ']' . $attach['name'] . '[/img]';
 137                                 }
 138                         } elseif ($filetype == 'audio') {
 139                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 140                                         continue;
 141                                 }
 142
 143                                 $item['body'] .= "\n[audio]" . $attach['url'] . '[/audio]';
 144                         } elseif ($filetype == 'video') {
 145                                 if (!empty($activity['source']) && strpos($activity['source'], $attach['url'])) {
 146                                         continue;
 147                                 }
 148
 149                                 $item['body'] .= "\n[video]" . $attach['url'] . '[/video]';
 150                         } else {
 151                                 if (!empty($item["attach"])) {
 152                                         $item["attach"] .= ',';
 153                                 } else {
 154                                         $item["attach"] = '';
 155                                 }
 156                                 if (!isset($attach['length'])) {
 157                                         $attach['length'] = "0";
 158                                 }
 159                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.($attach['name'] ?? '') .'"[/attach]';
 160                         }
 161                 }
 162
 163                 return $item;
 164         }
 165
 166         /**
 167          * Updates a message
 168          *
 169          * @param array $activity Activity array
 170          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 171          */
 172         public static function updateItem($activity)
 173         {
 174                 $item = Item::selectFirst(['uri', 'uri-id', 'thr-parent', 'gravity'], ['uri' => $activity['id']]);
 175                 if (!DBA::isResult($item)) {
 176                         Logger::warning('Unknown item', ['uri' => $activity['id']]);
 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 $item;
 422         }
 423
 424         private static function storeFromBody($item)
 425         {
 426                 // Make sure to delete all existing tags (can happen when called via the update functionality)
 427                 DBA::delete('post-tag', ['uri-id' => $uriid]);
 428
 429                 Tag::storeFromBody($item['uri-id'], $item['body'], '@!');
 430         }
 431
 432         /**
 433          * Generate a GUID out of an URL
 434          *
 435          * @param string $url message URL
 436          * @return string with GUID
 437          */
 438         private static function getGUIDByURL(string $url)
 439         {
 440                 $parsed = parse_url($url);
 441
 442                 $host_hash = hash('crc32', $parsed['host']);
 443
 444                 unset($parsed["scheme"]);
 445                 unset($parsed["host"]);
 446
 447                 $path = implode("/", $parsed);
 448
 449                 return $host_hash . '-'. hash('fnv164', $path) . '-'. hash('joaat', $path);
 450         }
 451
 452         /**
 453          * Creates an item post
 454          *
 455          * @param array $activity Activity data
 456          * @param array $item     item array
 457          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 458          * @throws \ImagickException
 459          */
 460         private static function postItem($activity, $item)
 461         {
 462                 /// @todo What to do with $activity['context']?
 463                 if (empty($activity['directmessage']) && ($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['thr-parent']])) {
 464                         Logger::info('Parent not found, message will be discarded.', ['thr-parent' => $item['thr-parent']]);
 465                         return;
 466                 }
 467
 468                 $item['network'] = Protocol::ACTIVITYPUB;
 469                 $item['author-link'] = $activity['author'];
 470                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
 471                 $item['owner-link'] = $activity['actor'];
 472                 $item['owner-id'] = Contact::getIdForURL($activity['actor'], 0, true);
 473
 474                 if (in_array(0, $activity['receiver']) && !empty($activity['unlisted'])) {
 475                         $item['private'] = Item::UNLISTED;
 476                 } elseif (in_array(0, $activity['receiver'])) {
 477                         $item['private'] = Item::PUBLIC;
 478                 } else {
 479                         $item['private'] = Item::PRIVATE;
 480                 }
 481
 482                 if (!empty($activity['raw'])) {
 483                         $item['source'] = $activity['raw'];
 484                         $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
 485                         $item['conversation-href'] = $activity['context'] ?? '';
 486                         $item['conversation-uri'] = $activity['conversation'] ?? '';
 487
 488                         if (isset($activity['push'])) {
 489                                 $item['direction'] = $activity['push'] ? Conversation::PUSH : Conversation::PULL;
 490                         }
 491                 }
 492
 493                 $isForum = false;
 494
 495                 if (!empty($activity['thread-completion'])) {
 496                         // Store the original actor in the "causer" fields to enable the check for ignored or blocked contacts
 497                         $item['causer-link'] = $item['owner-link'];
 498                         $item['causer-id'] = $item['owner-id'];
 499
 500                         Logger::info('Ignoring actor because of thread completion.', ['actor' => $item['owner-link']]);
 501                         $item['owner-link'] = $item['author-link'];
 502                         $item['owner-id'] = $item['author-id'];
 503                 } else {
 504                         $actor = APContact::getByURL($item['owner-link'], false);
 505                         $isForum = ($actor['type'] == 'Group');
 506                 }
 507
 508                 $item['uri'] = $activity['id'];
 509
 510                 $item['created'] = DateTimeFormat::utc($activity['published']);
 511                 $item['edited'] = DateTimeFormat::utc($activity['updated']);
 512                 $item['guid'] = $activity['diaspora:guid'] ?: $activity['sc:identifier'] ?: self::getGUIDByURL($item['uri']);
 513
 514                 $item['uri-id'] = ItemURI::insert(['uri' => $item['uri'], 'guid' => $item['guid']]);
 515
 516                 $item = self::processContent($activity, $item);
 517                 if (empty($item)) {
 518                         return;
 519                 }
 520
 521                 $item['plink'] = $activity['alternate-url'] ?? $item['uri'];
 522
 523                 $item = self::constructAttachList($activity, $item);
 524
 525                 $stored = false;
 526
 527                 foreach ($activity['receiver'] as $receiver) {
 528                         if ($receiver == -1) {
 529                                 continue;
 530                         }
 531
 532                         $item['uid'] = $receiver;
 533
 534                         if ($isForum) {
 535                                 $item['contact-id'] = Contact::getIdForURL($activity['actor'], $receiver, true);
 536                         } else {
 537                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
 538                         }
 539
 540                         if (($receiver != 0) && empty($item['contact-id'])) {
 541                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
 542                         }
 543
 544                         if (!empty($activity['directmessage'])) {
 545                                 self::postMail($activity, $item);
 546                                 continue;
 547                         }
 548
 549                         if (DI::pConfig()->get($receiver, 'system', 'accept_only_sharer', false) && ($receiver != 0) && ($item['gravity'] == GRAVITY_PARENT)) {
 550                                 $skip = !Contact::isSharingByURL($activity['author'], $receiver);
 551
 552                                 if ($skip && (($activity['type'] == 'as:Announce') || $isForum)) {
 553                                         $skip = !Contact::isSharingByURL($activity['actor'], $receiver);
 554                                 }
 555
 556                                 if ($skip) {
 557                                         Logger::info('Skipping post', ['uid' => $receiver, 'url' => $item['uri']]);
 558                                         continue;
 559                                 }
 560
 561                                 Logger::info('Accepting post', ['uid' => $receiver, 'url' => $item['uri']]);
 562                         }
 563
 564                         if (($item['gravity'] != GRAVITY_ACTIVITY) && ($activity['object_type'] == 'as:Event')) {
 565                                 self::createEvent($activity, $item);
 566                         }
 567
 568                         $item_id = Item::insert($item);
 569                         if ($item_id) {
 570                                 Logger::info('Item insertion successful', ['user' => $item['uid'], 'item_id' => $item_id]);
 571                         } else {
 572                                 Logger::notice('Item insertion aborted', ['user' => $item['uid']]);
 573                         }
 574
 575                         if ($item['uid'] == 0) {
 576                                 $stored = $item_id;
 577                         }
 578                 }
 579
 580                 // Store send a follow request for every reshare - but only when the item had been stored
 581                 if ($stored && ($item['private'] != Item::PRIVATE) && ($item['gravity'] == GRAVITY_PARENT) && ($item['author-link'] != $item['owner-link'])) {
 582                         $author = APContact::getByURL($item['owner-link'], false);
 583                         // We send automatic follow requests for reshared messages. (We don't need though for forum posts)
 584                         if ($author['type'] != 'Group') {
 585                                 Logger::log('Send follow request for ' . $item['uri'] . ' (' . $stored . ') to ' . $item['author-link'], Logger::DEBUG);
 586                                 ActivityPub\Transmitter::sendFollowObject($item['uri'], $item['author-link']);
 587                         }
 588                 }
 589         }
 590
 591         /**
 592          * Store tags and mentions into the tag table
 593          *
 594          * @param integer $uriid
 595          * @param array $tags
 596          */
 597         private static function storeTags(int $uriid, array $tags = null)
 598         {
 599                 foreach ($tags as $tag) {
 600                         if (empty($tag['name']) || empty($tag['type']) || !in_array($tag['type'], ['Mention', 'Hashtag'])) {
 601                                 continue;
 602                         }
 603
 604                         $hash = substr($tag['name'], 0, 1);
 605
 606                         if ($tag['type'] == 'Mention') {
 607                                 if (in_array($hash, [Tag::TAG_CHARACTER[Tag::MENTION],
 608                                         Tag::TAG_CHARACTER[Tag::EXCLUSIVE_MENTION],
 609                                         Tag::TAG_CHARACTER[Tag::IMPLICIT_MENTION]])) {
 610                                         $tag['name'] = substr($tag['name'], 1);
 611                                 }
 612                                 $type = Tag::IMPLICIT_MENTION;
 613
 614                                 if (!empty($tag['href'])) {
 615                                         $apcontact = APContact::getByURL($tag['href']);
 616                                         if (!empty($apcontact['name']) || !empty($apcontact['nick'])) {
 617                                                 $tag['name'] = $apcontact['name'] ?: $apcontact['nick'];
 618                                         }
 619                                 }
 620                         } elseif ($tag['type'] == 'Hashtag') {
 621                                 if ($hash == Tag::TAG_CHARACTER[Tag::HASHTAG]) {
 622                                         $tag['name'] = substr($tag['name'], 1);
 623                                 }
 624                                 $type = Tag::HASHTAG;
 625                         }
 626
 627                         if (empty($tag['name'])) {
 628                                 continue;
 629                         }
 630
 631                         Tag::store($uriid, $type, $tag['name'], $tag['href']);
 632                 }
 633         }
 634
 635         /**
 636          * Creates an mail post
 637          *
 638          * @param array $activity Activity data
 639          * @param array $item     item array
 640          * @return int|bool New mail table row id or false on error
 641          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 642          */
 643         private static function postMail($activity, $item)
 644         {
 645                 if (($item['gravity'] != GRAVITY_PARENT) && !DBA::exists('mail', ['uri' => $item['thr-parent'], 'uid' => $item['uid']])) {
 646                         Logger::info('Parent not found, mail will be discarded.', ['uid' => $item['uid'], 'uri' => $item['thr-parent']]);
 647                         return false;
 648                 }
 649
 650                 Logger::info('Direct Message', $item);
 651
 652                 $msg = [];
 653                 $msg['uid'] = $item['uid'];
 654
 655                 $msg['contact-id'] = $item['contact-id'];
 656
 657                 $contact = Contact::getById($item['contact-id'], ['name', 'url', 'photo']);
 658                 $msg['from-name'] = $contact['name'];
 659                 $msg['from-url'] = $contact['url'];
 660                 $msg['from-photo'] = $contact['photo'];
 661
 662                 $msg['uri'] = $item['uri'];
 663                 $msg['created'] = $item['created'];
 664
 665                 $parent = DBA::selectFirst('mail', ['parent-uri', 'title'], ['uri' => $item['thr-parent']]);
 666                 if (DBA::isResult($parent)) {
 667                         $msg['parent-uri'] = $parent['parent-uri'];
 668                         $msg['title'] = $parent['title'];
 669                 } else {
 670                         $msg['parent-uri'] = $item['thr-parent'];
 671
 672                         if (!empty($item['title'])) {
 673                                 $msg['title'] = $item['title'];
 674                         } elseif (!empty($item['content-warning'])) {
 675                                 $msg['title'] = $item['content-warning'];
 676                         } else {
 677                                 // Trying to generate a title out of the body
 678                                 $title = $item['body'];
 679
 680                                 while (preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $title, $matches)) {
 681                                         $title = $matches[3];
 682                                 }
 683
 684                                 $title = trim(HTML::toPlaintext(BBCode::convert($title, false, 2, true), 0));
 685
 686                                 if (strlen($title) > 20) {
 687                                         $title = substr($title, 0, 20) . '...';
 688                                 }
 689
 690                                 $msg['title'] = $title;
 691                         }
 692                 }
 693                 $msg['body'] = $item['body'];
 694
 695                 return Mail::insert($msg);
 696         }
 697
 698         /**
 699          * Fetches missing posts
 700          *
 701          * @param string $url message URL
 702          * @param array $child activity array with the child of this message
 703          * @return string fetched message URL
 704          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 705          */
 706         public static function fetchMissingActivity($url, $child = [])
 707         {
 708                 if (!empty($child['receiver'])) {
 709                         $uid = ActivityPub\Receiver::getFirstUserFromReceivers($child['receiver']);
 710                 } else {
 711                         $uid = 0;
 712                 }
 713
 714                 $object = ActivityPub::fetchContent($url, $uid);
 715                 if (empty($object)) {
 716                         Logger::log('Activity ' . $url . ' was not fetchable, aborting.');
 717                         return '';
 718                 }
 719
 720                 if (empty($object['id'])) {
 721                         Logger::log('Activity ' . $url . ' has got not id, aborting. ' . json_encode($object));
 722                         return '';
 723                 }
 724
 725                 if (!empty($child['author'])) {
 726                         $actor = $child['author'];
 727                 } elseif (!empty($object['actor'])) {
 728                         $actor = $object['actor'];
 729                 } elseif (!empty($object['attributedTo'])) {
 730                         $actor = $object['attributedTo'];
 731                 } else {
 732                         // Shouldn't happen
 733                         $actor = '';
 734                 }
 735
 736                 if (!empty($object['published'])) {
 737                         $published = $object['published'];
 738                 } elseif (!empty($child['published'])) {
 739                         $published = $child['published'];
 740                 } else {
 741                         $published = DateTimeFormat::utcNow();
 742                 }
 743
 744                 $activity = [];
 745                 $activity['@context'] = $object['@context'];
 746                 unset($object['@context']);
 747                 $activity['id'] = $object['id'];
 748                 $activity['to'] = $object['to'] ?? [];
 749                 $activity['cc'] = $object['cc'] ?? [];
 750                 $activity['actor'] = $actor;
 751                 $activity['object'] = $object;
 752                 $activity['published'] = $published;
 753                 $activity['type'] = 'Create';
 754
 755                 $ldactivity = JsonLD::compact($activity);
 756
 757                 $ldactivity['thread-completion'] = true;
 758
 759                 ActivityPub\Receiver::processActivity($ldactivity, json_encode($activity));
 760
 761                 Logger::notice('Activity had been fetched and processed.', ['url' => $url, 'object' => $activity['id']]);
 762
 763                 return $activity['id'];
 764         }
 765
 766         /**
 767          * perform a "follow" request
 768          *
 769          * @param array $activity
 770          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 771          * @throws \ImagickException
 772          */
 773         public static function followUser($activity)
 774         {
 775                 $uid = User::getIdForURL($activity['object_id']);
 776                 if (empty($uid)) {
 777                         return;
 778                 }
 779
 780                 $owner = User::getOwnerDataById($uid);
 781
 782                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 783                 if (!empty($cid)) {
 784                         self::switchContact($cid);
 785                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 786                         $contact = DBA::selectFirst('contact', [], ['id' => $cid, 'network' => Protocol::NATIVE_SUPPORT]);
 787                 } else {
 788                         $contact = [];
 789                 }
 790
 791                 $item = ['author-id' => Contact::getIdForURL($activity['actor']),
 792                         'author-link' => $activity['actor']];
 793
 794                 $note = Strings::escapeTags(trim($activity['content'] ?? ''));
 795
 796                 // Ensure that the contact has got the right network type
 797                 self::switchContact($item['author-id']);
 798
 799                 $result = Contact::addRelationship($owner, $contact, $item, false, $note);
 800                 if ($result === true) {
 801                         ActivityPub\Transmitter::sendContactAccept($item['author-link'], $item['author-id'], $owner['uid']);
 802                 }
 803
 804                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 805                 if (empty($cid)) {
 806                         return;
 807                 }
 808
 809                 if (empty($contact)) {
 810                         DBA::update('contact', ['hub-verify' => $activity['id'], 'protocol' => Protocol::ACTIVITYPUB], ['id' => $cid]);
 811                 }
 812
 813                 Logger::log('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
 814         }
 815
 816         /**
 817          * Update the given profile
 818          *
 819          * @param array $activity
 820          * @throws \Exception
 821          */
 822         public static function updatePerson($activity)
 823         {
 824                 if (empty($activity['object_id'])) {
 825                         return;
 826                 }
 827
 828                 Logger::log('Updating profile for ' . $activity['object_id'], Logger::DEBUG);
 829                 Contact::updateFromProbeByURL($activity['object_id'], true);
 830         }
 831
 832         /**
 833          * Delete the given profile
 834          *
 835          * @param array $activity
 836          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 837          */
 838         public static function deletePerson($activity)
 839         {
 840                 if (empty($activity['object_id']) || empty($activity['actor'])) {
 841                         Logger::log('Empty object id or actor.', Logger::DEBUG);
 842                         return;
 843                 }
 844
 845                 if ($activity['object_id'] != $activity['actor']) {
 846                         Logger::log('Object id does not match actor.', Logger::DEBUG);
 847                         return;
 848                 }
 849
 850                 $contacts = DBA::select('contact', ['id'], ['nurl' => Strings::normaliseLink($activity['object_id'])]);
 851                 while ($contact = DBA::fetch($contacts)) {
 852                         Contact::remove($contact['id']);
 853                 }
 854                 DBA::close($contacts);
 855
 856                 Logger::log('Deleted contact ' . $activity['object_id'], Logger::DEBUG);
 857         }
 858
 859         /**
 860          * Accept a follow request
 861          *
 862          * @param array $activity
 863          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 864          * @throws \ImagickException
 865          */
 866         public static function acceptFollowUser($activity)
 867         {
 868                 $uid = User::getIdForURL($activity['object_actor']);
 869                 if (empty($uid)) {
 870                         return;
 871                 }
 872
 873                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 874                 if (empty($cid)) {
 875                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 876                         return;
 877                 }
 878
 879                 self::switchContact($cid);
 880
 881                 $fields = ['pending' => false];
 882
 883                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
 884                 if ($contact['rel'] == Contact::FOLLOWER) {
 885                         $fields['rel'] = Contact::FRIEND;
 886                 }
 887
 888                 $condition = ['id' => $cid];
 889                 DBA::update('contact', $fields, $condition);
 890                 Logger::log('Accept contact request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 891         }
 892
 893         /**
 894          * Reject a follow request
 895          *
 896          * @param array $activity
 897          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 898          * @throws \ImagickException
 899          */
 900         public static function rejectFollowUser($activity)
 901         {
 902                 $uid = User::getIdForURL($activity['object_actor']);
 903                 if (empty($uid)) {
 904                         return;
 905                 }
 906
 907                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 908                 if (empty($cid)) {
 909                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 910                         return;
 911                 }
 912
 913                 self::switchContact($cid);
 914
 915                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING])) {
 916                         Contact::remove($cid);
 917                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . ' - contact had been removed.', Logger::DEBUG);
 918                 } else {
 919                         Logger::log('Rejected contact request from contact ' . $cid . ' for user ' . $uid . '.', Logger::DEBUG);
 920                 }
 921         }
 922
 923         /**
 924          * Undo activity like "like" or "dislike"
 925          *
 926          * @param array $activity
 927          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 928          * @throws \ImagickException
 929          */
 930         public static function undoActivity($activity)
 931         {
 932                 if (empty($activity['object_id'])) {
 933                         return;
 934                 }
 935
 936                 if (empty($activity['object_actor'])) {
 937                         return;
 938                 }
 939
 940                 $author_id = Contact::getIdForURL($activity['object_actor']);
 941                 if (empty($author_id)) {
 942                         return;
 943                 }
 944
 945                 Item::markForDeletion(['uri' => $activity['object_id'], 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
 946         }
 947
 948         /**
 949          * Activity to remove a follower
 950          *
 951          * @param array $activity
 952          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 953          * @throws \ImagickException
 954          */
 955         public static function undoFollowUser($activity)
 956         {
 957                 $uid = User::getIdForURL($activity['object_object']);
 958                 if (empty($uid)) {
 959                         return;
 960                 }
 961
 962                 $owner = User::getOwnerDataById($uid);
 963
 964                 $cid = Contact::getIdForURL($activity['actor'], $uid);
 965                 if (empty($cid)) {
 966                         Logger::log('No contact found for ' . $activity['actor'], Logger::DEBUG);
 967                         return;
 968                 }
 969
 970                 self::switchContact($cid);
 971
 972                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
 973                 if (!DBA::isResult($contact)) {
 974                         return;
 975                 }
 976
 977                 Contact::removeFollower($owner, $contact);
 978                 Logger::log('Undo following request from contact ' . $cid . ' for user ' . $uid, Logger::DEBUG);
 979         }
 980
 981         /**
 982          * Switches a contact to AP if needed
 983          *
 984          * @param integer $cid Contact ID
 985          * @throws \Exception
 986          */
 987         private static function switchContact($cid)
 988         {
 989                 $contact = DBA::selectFirst('contact', ['network', 'url'], ['id' => $cid]);
 990                 if (!DBA::isResult($contact) || in_array($contact['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN]) || Contact::isLocal($contact['url'])) {
 991                         return;
 992                 }
 993
 994                 Logger::info('Change existing contact', ['cid' => $cid, 'previous' => $contact['network']]);
 995                 Contact::updateFromProbe($cid);
 996         }
 997
 998         /**
 999          * Collects implicit mentions like:
1000          * - the author of the parent item
1001          * - all the mentioned conversants in the parent item
1002          *
1003          * @param array $parent Item array with at least ['id', 'author-link', 'alias']
1004          * @return array
1005          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1006          */
1007         private static function getImplicitMentionList(array $parent)
1008         {
1009                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1010                         return [];
1011                 }
1012
1013                 $parent_terms = Term::tagArrayFromItemId($parent['id'], [Term::MENTION, Term::IMPLICIT_MENTION]);
1014
1015                 $parent_author = Contact::getDetailsByURL($parent['author-link'], 0);
1016
1017                 $implicit_mentions = [];
1018                 if (empty($parent_author)) {
1019                         Logger::notice('Author public contact unknown.', ['author-link' => $parent['author-link'], 'item-id' => $parent['id']]);
1020                 } else {
1021                         $implicit_mentions[] = $parent_author['url'];
1022                         $implicit_mentions[] = $parent_author['nurl'];
1023                         $implicit_mentions[] = $parent_author['alias'];
1024                 }
1025
1026                 if (!empty($parent['alias'])) {
1027                         $implicit_mentions[] = $parent['alias'];
1028                 }
1029
1030                 foreach ($parent_terms as $term) {
1031                         $contact = Contact::getDetailsByURL($term['url'], 0);
1032                         if (!empty($contact)) {
1033                                 $implicit_mentions[] = $contact['url'];
1034                                 $implicit_mentions[] = $contact['nurl'];
1035                                 $implicit_mentions[] = $contact['alias'];
1036                         }
1037                 }
1038
1039                 return $implicit_mentions;
1040         }
1041
1042         /**
1043          * Strips from the body prepended implicit mentions
1044          *
1045          * @param string $body
1046          * @param array $potential_mentions
1047          * @return string
1048          */
1049         private static function removeImplicitMentionsFromBody($body, array $potential_mentions)
1050         {
1051                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1052                         return $body;
1053                 }
1054
1055                 $kept_mentions = [];
1056
1057                 // Extract one prepended mention at a time from the body
1058                 while(preg_match('#^(@\[url=([^\]]+)].*?\[\/url]\s)(.*)#is', $body, $matches)) {
1059                         if (!in_array($matches[2], $potential_mentions)) {
1060                                 $kept_mentions[] = $matches[1];
1061                         }
1062
1063                         $body = $matches[3];
1064                 }
1065
1066                 // Re-appending the kept mentions to the body after extraction
1067                 $kept_mentions[] = $body;
1068
1069                 return implode('', $kept_mentions);
1070         }
1071
1072         private static function convertImplicitMentionsInTags($activity_tags, array $potential_mentions)
1073         {
1074                 if (DI::config()->get('system', 'disable_implicit_mentions')) {
1075                         return $activity_tags;
1076                 }
1077
1078                 foreach ($activity_tags as $index => $tag) {
1079                         if (in_array($tag['href'], $potential_mentions)) {
1080                                 $activity_tags[$index]['name'] = preg_replace(
1081                                         '/' . preg_quote(Term::TAG_CHARACTER[Term::MENTION], '/') . '/',
1082                                         Term::TAG_CHARACTER[Term::IMPLICIT_MENTION],
1083                                         $activity_tags[$index]['name'],
1084                                         1
1085                                 );
1086                         }
1087                 }
1088
1089                 return $activity_tags;
1090         }
1091 }