src/Protocol/ActivityPub/Transmitter.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, the Friendica project
   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\Feature;
  25 use Friendica\Content\Text\BBCode;
  26 use Friendica\Core\Cache\Enum\Duration;
  27 use Friendica\Core\Logger;
  28 use Friendica\Core\Protocol;
  29 use Friendica\Core\System;
  30 use Friendica\Database\DBA;
  31 use Friendica\DI;
  32 use Friendica\Model\APContact;
  33 use Friendica\Model\Contact;
  34 use Friendica\Model\Conversation;
  35 use Friendica\Model\GServer;
  36 use Friendica\Model\Item;
  37 use Friendica\Model\Photo;
  38 use Friendica\Model\Post;
  39 use Friendica\Model\Tag;
  40 use Friendica\Model\User;
  41 use Friendica\Network\HTTPException;
  42 use Friendica\Protocol\Activity;
  43 use Friendica\Protocol\ActivityPub;
  44 use Friendica\Protocol\Relay;
  45 use Friendica\Util\DateTimeFormat;
  46 use Friendica\Util\HTTPSignature;
  47 use Friendica\Util\JsonLD;
  48 use Friendica\Util\LDSignature;
  49 use Friendica\Util\Map;
  50 use Friendica\Util\Network;
  51 use Friendica\Util\Strings;
  52 use Friendica\Util\XML;
  53
  54 /**
  55  * ActivityPub Transmitter Protocol class
  56  *
  57  * To-Do:
  58  * @todo Undo Announce
  59  */
  60 class Transmitter
  61 {
  62         /**
  63          * Add relay servers to the list of inboxes
  64          *
  65          * @param array $inboxes
  66          * @return array inboxes with added relay servers
  67          */
  68         public static function addRelayServerInboxes(array $inboxes = [])
  69         {
  70                 foreach (Relay::getList(['inbox']) as $contact) {
  71                         $inboxes[$contact['inbox']] = $contact['inbox'];
  72                 }
  73
  74                 return $inboxes;
  75         }
  76
  77         /**
  78          * Add relay servers to the list of inboxes
  79          *
  80          * @param array $inboxes
  81          * @return array inboxes with added relay servers
  82          */
  83         public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = [])
  84         {
  85                 $item = Post::selectFirst(['uid'], ['id' => $item_id]);
  86                 if (empty($item)) {
  87                         return $inboxes;
  88                 }
  89
  90                 $relays = Relay::getDirectRelayList($item_id);
  91                 if (empty($relays)) {
  92                         return $inboxes;
  93                 }
  94
  95                 foreach ($relays as $relay) {
  96                         $contact = Contact::getByURLForUser($relay['url'], $item['uid'], false, ['id']);
  97                         $inboxes[$relay['batch']][] = $contact['id'] ?? 0;
  98                 }
  99                 return $inboxes;
 100         }
 101
 102         /**
 103          * Subscribe to a relay
 104          *
 105          * @param string $url Subscribe actor url
 106          * @return bool success
 107          */
 108         public static function sendRelayFollow(string $url)
 109         {
 110                 $contact = Contact::getByURL($url);
 111                 if (empty($contact)) {
 112                         return false;
 113                 }
 114
 115                 $activity_id = ActivityPub\Transmitter::activityIDFromContact($contact['id']);
 116                 $success = ActivityPub\Transmitter::sendActivity('Follow', $url, 0, $activity_id);
 117                 if ($success) {
 118                         Contact::update(['rel' => Contact::FRIEND], ['id' => $contact['id']]);
 119                 }
 120
 121                 return $success;
 122         }
 123
 124         /**
 125          * Unsubscribe from a relay
 126          *
 127          * @param string $url   Subscribe actor url
 128          * @param bool   $force Set the relay status as non follower even if unsubscribe hadn't worked
 129          * @return bool success
 130          */
 131         public static function sendRelayUndoFollow(string $url, bool $force = false)
 132         {
 133                 $contact = Contact::getByURL($url);
 134                 if (empty($contact)) {
 135                         return false;
 136                 }
 137
 138                 $success = self::sendContactUndo($url, $contact['id'], 0);
 139                 if ($success || $force) {
 140                         Contact::update(['rel' => Contact::NOTHING], ['id' => $contact['id']]);
 141                 }
 142
 143                 return $success;
 144         }
 145
 146         /**
 147          * Collects a list of contacts of the given owner
 148          *
 149          * @param array     $owner     Owner array
 150          * @param int|array $rel       The relevant value(s) contact.rel should match
 151          * @param string    $module    The name of the relevant AP endpoint module (followers|following)
 152          * @param integer   $page      Page number
 153          * @param string    $requester URL of the requester
 154          *
 155          * @return array of owners
 156          * @throws \Exception
 157          */
 158         public static function getContacts($owner, $rel, $module, $page = null, string $requester = null)
 159         {
 160                 $parameters = [
 161                         'rel' => $rel,
 162                         'uid' => $owner['uid'],
 163                         'self' => false,
 164                         'deleted' => false,
 165                         'hidden' => false,
 166                         'archive' => false,
 167                         'pending' => false,
 168                         'blocked' => false,
 169                 ];
 170
 171                 $condition = DBA::mergeConditions($parameters, ["`url` IN (SELECT `url` FROM `apcontact`)"]);
 172
 173                 $total = DBA::count('contact', $condition);
 174
 175                 $modulePath = '/' . $module . '/';
 176
 177                 $data = ['@context' => ActivityPub::CONTEXT];
 178                 $data['id'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 179                 $data['type'] = 'OrderedCollection';
 180                 $data['totalItems'] = $total;
 181
 182                 // When we hide our friends we will only show the pure number but don't allow more.
 183                 $show_contacts = empty($owner['hide-friends']);
 184
 185                 // Allow fetching the contact list when the requester is part of the list.
 186                 if (($owner['page-flags'] == User::PAGE_FLAGS_PRVGROUP) && !empty($requester)) {
 187                         $show_contacts = DBA::exists('contact', ['nurl' => Strings::normaliseLink($requester), 'uid' => $owner['uid'], 'blocked' => false]);
 188                 }
 189
 190                 if (!$show_contacts) {
 191                         return $data;
 192                 }
 193
 194                 if (empty($page)) {
 195                         $data['first'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=1';
 196                 } else {
 197                         $data['type'] = 'OrderedCollectionPage';
 198                         $list = [];
 199
 200                         $contacts = DBA::select('contact', ['url'], $condition, ['limit' => [($page - 1) * 100, 100]]);
 201                         while ($contact = DBA::fetch($contacts)) {
 202                                 $list[] = $contact['url'];
 203                         }
 204                         DBA::close($contacts);
 205
 206                         if (!empty($list)) {
 207                                 $data['next'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=' . ($page + 1);
 208                         }
 209
 210                         $data['partOf'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 211
 212                         $data['orderedItems'] = $list;
 213                 }
 214
 215                 return $data;
 216         }
 217
 218         /**
 219          * Public posts for the given owner
 220          *
 221          * @param array   $owner     Owner array
 222          * @param integer $page      Page number
 223          * @param string  $requester URL of requesting account
 224          *
 225          * @return array of posts
 226          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 227          * @throws \ImagickException
 228          */
 229         public static function getOutbox($owner, $page = null, $requester = '')
 230         {
 231                 $condition = ['private' => [Item::PUBLIC, Item::UNLISTED]];
 232
 233                 if (!empty($requester)) {
 234                         $requester_id = Contact::getIdForURL($requester, $owner['uid']);
 235                         if (!empty($requester_id)) {
 236                                 $permissionSets = DI::permissionSet()->selectByContactId($requester_id, $owner['uid']);
 237                                 if (!empty($permissionSets)) {
 238                                         $condition = ['psid' => array_merge($permissionSets->column('id'),
 239                                                         [DI::permissionSet()->selectPublicForUser($owner['uid'])])];
 240                                 }
 241                         }
 242                 }
 243
 244                 $condition = array_merge($condition,
 245                         ['uid'           => $owner['uid'],
 246                         'author-id'      => Contact::getIdForURL($owner['url'], 0, false),
 247                         'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
 248                         'network'        => Protocol::FEDERATED,
 249                         'parent-network' => Protocol::FEDERATED,
 250                         'origin'         => true,
 251                         'deleted'        => false,
 252                         'visible'        => true]);
 253
 254                 $count = Post::count($condition);
 255
 256                 $data = ['@context' => ActivityPub::CONTEXT];
 257                 $data['id'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 258                 $data['type'] = 'OrderedCollection';
 259                 $data['totalItems'] = $count;
 260
 261                 if (empty($page)) {
 262                         $data['first'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
 263                 } else {
 264                         $data['type'] = 'OrderedCollectionPage';
 265                         $list = [];
 266
 267                         $items = Post::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
 268                         while ($item = Post::fetch($items)) {
 269                                 $activity = self::createActivityFromItem($item['id'], true);
 270                                 $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
 271
 272                                 // Only list "Create" activity objects here, no reshares
 273                                 if (!empty($activity['object']) && ($activity['type'] == 'Create')) {
 274                                         $list[] = $activity['object'];
 275                                 }
 276                         }
 277                         DBA::close($items);
 278
 279                         if (!empty($list)) {
 280                                 $data['next'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
 281                         }
 282
 283                         $data['partOf'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 284
 285                         $data['orderedItems'] = $list;
 286                 }
 287
 288                 return $data;
 289         }
 290
 291         /**
 292          * Return the service array containing information the used software and it's url
 293          *
 294          * @return array with service data
 295          */
 296         private static function getService()
 297         {
 298                 return ['type' => 'Service',
 299                         'name' =>  FRIENDICA_PLATFORM . " '" . FRIENDICA_CODENAME . "' " . FRIENDICA_VERSION . '-' . DB_UPDATE_VERSION,
 300                         'url' => DI::baseUrl()->get()];
 301         }
 302
 303         /**
 304          * Return the ActivityPub profile of the given user
 305          *
 306          * @param int $uid User ID
 307          * @return array with profile data
 308          * @throws HTTPException\NotFoundException
 309          * @throws HTTPException\InternalServerErrorException
 310          */
 311         public static function getProfile(int $uid): array
 312         {
 313                 $owner = User::getOwnerDataById($uid);
 314                 if (!isset($owner['id'])) {
 315                         DI::logger()->error('Unable to find owner data for uid', ['uid' => $uid, 'callstack' => System::callstack(20)]);
 316                         throw new HTTPException\NotFoundException('User not found.');
 317                 }
 318
 319                 $data = ['@context' => ActivityPub::CONTEXT];
 320                 $data['id'] = $owner['url'];
 321
 322                 if (!empty($owner['guid'])) {
 323                         $data['diaspora:guid'] = $owner['guid'];
 324                 }
 325
 326                 $data['type'] = ActivityPub::ACCOUNT_TYPES[$owner['account-type']];
 327
 328                 if ($uid != 0) {
 329                         $data['following'] = DI::baseUrl() . '/following/' . $owner['nick'];
 330                         $data['followers'] = DI::baseUrl() . '/followers/' . $owner['nick'];
 331                         $data['inbox'] = DI::baseUrl() . '/inbox/' . $owner['nick'];
 332                         $data['outbox'] = DI::baseUrl() . '/outbox/' . $owner['nick'];
 333                 } else {
 334                         $data['inbox'] = DI::baseUrl() . '/friendica/inbox';
 335                 }
 336
 337                 $data['preferredUsername'] = $owner['nick'];
 338                 $data['name'] = $owner['name'];
 339
 340                 if (!empty($owner['country-name'] . $owner['region'] . $owner['locality'])) {
 341                         $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $owner['country-name'],
 342                                 'vcard:region' => $owner['region'], 'vcard:locality' => $owner['locality']];
 343                 }
 344
 345                 if (!empty($owner['about'])) {
 346                         $data['summary'] = BBCode::convertForUriId($owner['uri-id'] ?? 0, $owner['about'], BBCode::EXTERNAL);
 347                 }
 348
 349                 if (!empty($owner['xmpp']) || !empty($owner['matrix'])) {
 350                         $data['vcard:hasInstantMessage'] = [];
 351
 352                         if (!empty($owner['xmpp'])) {
 353                                 $data['vcard:hasInstantMessage'][] = 'xmpp:' . $owner['xmpp'];
 354                         }
 355                         if (!empty($owner['matrix'])) {
 356                                 $data['vcard:hasInstantMessage'][] = 'matrix:' . $owner['matrix'];
 357                         }
 358                 }
 359
 360                 $data['url'] = $owner['url'];
 361                 $data['manuallyApprovesFollowers'] = in_array($owner['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 362                 $data['discoverable'] = (bool)$owner['net-publish'];
 363                 $data['publicKey'] = ['id' => $owner['url'] . '#main-key',
 364                         'owner' => $owner['url'],
 365                         'publicKeyPem' => $owner['pubkey']];
 366                 $data['endpoints'] = ['sharedInbox' => DI::baseUrl() . '/inbox'];
 367                 $data['icon'] = ['type' => 'Image', 'url' => User::getAvatarUrl($owner)];
 368
 369                 $resourceid = Photo::ridFromURI($owner['photo']);
 370                 if (!empty($resourceid)) {
 371                         $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 372                         if (!empty($photo['type'])) {
 373                                 $data['icon']['mediaType'] = $photo['type'];
 374                         }
 375                 }
 376
 377                 if (!empty($owner['header'])) {
 378                         $data['image'] = ['type' => 'Image', 'url' => Contact::getHeaderUrlForId($owner['id'], '', $owner['updated'])];
 379
 380                         $resourceid = Photo::ridFromURI($owner['header']);
 381                         if (!empty($resourceid)) {
 382                                 $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 383                                 if (!empty($photo['type'])) {
 384                                         $data['image']['mediaType'] = $photo['type'];
 385                                 }
 386                         }
 387                 }
 388
 389                 $custom_fields = [];
 390
 391                 foreach (DI::profileField()->selectByContactId(0, $uid) as $profile_field) {
 392                         $custom_fields[] = [
 393                                 'type' => 'PropertyValue',
 394                                 'name' => $profile_field->label,
 395                                 'value' => BBCode::convertForUriId($owner['uri-id'], $profile_field->value)
 396                         ];
 397                 };
 398
 399                 if (!empty($custom_fields)) {
 400                         $data['attachment'] = $custom_fields;
 401                 }
 402
 403                 $data['generator'] = self::getService();
 404
 405                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 406                 return $data;
 407         }
 408
 409         /**
 410          * @param string $username
 411          * @return array
 412          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 413          */
 414         public static function getDeletedUser($username)
 415         {
 416                 return [
 417                         '@context' => ActivityPub::CONTEXT,
 418                         'id' => DI::baseUrl() . '/profile/' . $username,
 419                         'type' => 'Tombstone',
 420                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 421                         'updated' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 422                         'deleted' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 423                 ];
 424         }
 425
 426         /**
 427          * Returns an array with permissions of the thread parent of the given item array
 428          *
 429          * @param array $item
 430          * @param bool  $is_forum_thread
 431          *
 432          * @return array with permissions
 433          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 434          * @throws \ImagickException
 435          */
 436         private static function fetchPermissionBlockFromThreadParent(array $item, bool $is_forum_thread)
 437         {
 438                 if (empty($item['thr-parent-id'])) {
 439                         return [];
 440                 }
 441
 442                 $parent = Post::selectFirstPost(['author-link'], ['uri-id' => $item['thr-parent-id']]);
 443                 if (empty($parent)) {
 444                         return [];
 445                 }
 446
 447                 $permissions = [
 448                         'to' => [$parent['author-link']],
 449                         'cc' => [],
 450                         'bto' => [],
 451                         'bcc' => [],
 452                 ];
 453
 454                 $parent_profile = APContact::getByURL($parent['author-link']);
 455
 456                 $item_profile = APContact::getByURL($item['author-link']);
 457                 $exclude[] = $item['author-link'];
 458
 459                 if ($item['gravity'] == GRAVITY_PARENT) {
 460                         $exclude[] = $item['owner-link'];
 461                 }
 462
 463                 $type = [Tag::TO => 'to', Tag::CC => 'cc', Tag::BTO => 'bto', Tag::BCC => 'bcc'];
 464                 foreach (Tag::getByURIId($item['thr-parent-id'], [Tag::TO, Tag::CC, Tag::BTO, Tag::BCC]) as $receiver) {
 465                         if (!empty($parent_profile['followers']) && $receiver['url'] == $parent_profile['followers'] && !empty($item_profile['followers'])) {
 466                                 if (!$is_forum_thread) {
 467                                         $permissions[$type[$receiver['type']]][] = $item_profile['followers'];
 468                                 }
 469                         } elseif (!in_array($receiver['url'], $exclude)) {
 470                                 $permissions[$type[$receiver['type']]][] = $receiver['url'];
 471                         }
 472                 }
 473
 474                 return $permissions;
 475         }
 476
 477         /**
 478          * Check if the given item id is from ActivityPub
 479          *
 480          * @param integer $item_id
 481          * @return boolean "true" if the post is from ActivityPub
 482          */
 483         private static function isAPPost(int $item_id)
 484         {
 485                 if (empty($item_id)) {
 486                         return false;
 487                 }
 488
 489                 return Post::exists(['id' => $item_id, 'network' => Protocol::ACTIVITYPUB]);
 490         }
 491
 492         /**
 493          * Creates an array of permissions from an item thread
 494          *
 495          * @param array   $item      Item array
 496          * @param boolean $blindcopy addressing via "bcc" or "cc"?
 497          * @param integer $last_id   Last item id for adding receivers
 498          *
 499          * @return array with permission data
 500          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 501          * @throws \ImagickException
 502          */
 503         private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0)
 504         {
 505                 if ($last_id == 0) {
 506                         $last_id = $item['id'];
 507                 }
 508
 509                 $always_bcc = false;
 510                 $is_forum   = false;
 511                 $follower   = '';
 512
 513                 // Check if we should always deliver our stuff via BCC
 514                 if (!empty($item['uid'])) {
 515                         $owner = User::getOwnerDataById($item['uid']);
 516                         if (!empty($owner)) {
 517                                 $always_bcc = $owner['hide-friends'];
 518                                 $is_forum   = ($owner['account-type'] == User::ACCOUNT_TYPE_COMMUNITY) && $owner['manually-approve'];
 519
 520                                 $profile  = APContact::getByURL($owner['url'], false);
 521                                 $follower = $profile['followers'] ?? '';
 522                         }
 523                 }
 524
 525                 if (DI::config()->get('system', 'ap_always_bcc')) {
 526                         $always_bcc = true;
 527                 }
 528
 529                 $parent = Post::selectFirst(['causer-link', 'post-reason'], ['id' => $item['parent']]);
 530                 if (($parent['post-reason'] == Item::PR_ANNOUNCEMENT) && !empty($parent['causer-link'])) {
 531                         $profile = APContact::getByURL($parent['causer-link'], false);
 532                         $is_forum_thread = isset($profile['type']) && $profile['type'] == 'Group';
 533                 } else {
 534                         $is_forum_thread = false;
 535                 }
 536
 537                 if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery') || self::isAPPost($last_id)) {
 538                         // Will be activated in a later step
 539                         $networks = Protocol::FEDERATED;
 540                 } else {
 541                         // For now only send to these contacts:
 542                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 543                 }
 544
 545                 $data = ['to' => [], 'cc' => [], 'bcc' => []];
 546
 547                 if ($item['gravity'] == GRAVITY_PARENT) {
 548                         $actor_profile = APContact::getByURL($item['owner-link']);
 549                 } else {
 550                         $actor_profile = APContact::getByURL($item['author-link']);
 551                 }
 552
 553                 $exclusive = false;
 554
 555                 $terms = Tag::getByURIId($item['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
 556
 557                 if ($item['private'] != Item::PRIVATE) {
 558                         // Directly mention the original author upon a quoted reshare.
 559                         // Else just ensure that the original author receives the reshare.
 560                         $announce = self::getAnnounceArray($item);
 561                         if (!empty($announce['comment'])) {
 562                                 $data['to'][] = $announce['actor']['url'];
 563                         } elseif (!empty($announce)) {
 564                                 $data['cc'][] = $announce['actor']['url'];
 565                         }
 566
 567                         $data = array_merge($data, self::fetchPermissionBlockFromThreadParent($item, $is_forum_thread));
 568
 569                         // Check if the item is completely public or unlisted
 570                         if ($item['private'] == Item::PUBLIC) {
 571                                 $data['to'][] = ActivityPub::PUBLIC_COLLECTION;
 572                         } else {
 573                                 $data['cc'][] = ActivityPub::PUBLIC_COLLECTION;
 574                         }
 575
 576                         foreach ($terms as $term) {
 577                                 $profile = APContact::getByURL($term['url'], false);
 578                                 if (!empty($profile)) {
 579                                         if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
 580                                                 $exclusive = true;
 581                                                 if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
 582                                                         $data['cc'][] = $profile['followers'];
 583                                                 }
 584                                         }
 585                                         $data['to'][] = $profile['url'];
 586                                 }
 587                         }
 588                 } else {
 589                         $receiver_list = Item::enumeratePermissions($item, true);
 590
 591                         foreach ($terms as $term) {
 592                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 593                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 594                                         $contact = DBA::selectFirst('contact', ['url', 'network', 'protocol', 'gsid'], ['id' => $cid, 'network' => Protocol::FEDERATED]);
 595                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 596                                                 continue;
 597                                         }
 598
 599                                         $profile = APContact::getByURL($term['url'], false);
 600                                         if (!empty($profile)) {
 601                                                 if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
 602                                                         $exclusive = true;
 603                                                         if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
 604                                                                 $data['cc'][] = $profile['followers'];
 605                                                         }
 606                                                 }
 607                                                 $data['to'][] = $profile['url'];
 608                                         }
 609                                 }
 610                         }
 611
 612                         if ($is_forum && !$exclusive && !empty($follower)) {
 613                                 $data['cc'][] = $follower;
 614                         } elseif (!$exclusive) {
 615                                 foreach ($receiver_list as $receiver) {
 616                                         $contact = DBA::selectFirst('contact', ['url', 'hidden', 'network', 'protocol', 'gsid'], ['id' => $receiver, 'network' => Protocol::FEDERATED]);
 617                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 618                                                 continue;
 619                                         }
 620
 621                                         if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 622                                                 if ($contact['hidden'] || $always_bcc) {
 623                                                         $data['bcc'][] = $profile['url'];
 624                                                 } else {
 625                                                         $data['cc'][] = $profile['url'];
 626                                                 }
 627                                         }
 628                                 }
 629                         }
 630                 }
 631
 632                 if (!empty($item['parent'])) {
 633                         $parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']], ['order' => ['id']]);
 634                         while ($parent = Post::fetch($parents)) {
 635                                 if ($parent['gravity'] == GRAVITY_PARENT) {
 636                                         $profile = APContact::getByURL($parent['owner-link'], false);
 637                                         if (!empty($profile)) {
 638                                                 if ($item['gravity'] != GRAVITY_PARENT) {
 639                                                         // Comments to forums are directed to the forum
 640                                                         // But comments to forums aren't directed to the followers collection
 641                                                         // This rule is only valid when the actor isn't the forum.
 642                                                         // The forum needs to transmit their content to their followers.
 643                                                         if (($profile['type'] == 'Group') && ($profile['url'] != ($actor_profile['url'] ?? ''))) {
 644                                                                 $data['to'][] = $profile['url'];
 645                                                         } else {
 646                                                                 $data['cc'][] = $profile['url'];
 647                                                                 if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])&& !$is_forum_thread) {
 648                                                                         $data['cc'][] = $actor_profile['followers'];
 649                                                                 }
 650                                                         }
 651                                                 } elseif (!$exclusive && !$is_forum_thread) {
 652                                                         // Public thread parent post always are directed to the followers.
 653                                                         if ($item['private'] != Item::PRIVATE) {
 654                                                                 $data['cc'][] = $actor_profile['followers'];
 655                                                         }
 656                                                 }
 657                                         }
 658                                 }
 659
 660                                 // Don't include data from future posts
 661                                 if ($parent['id'] >= $last_id) {
 662                                         continue;
 663                                 }
 664
 665                                 $profile = APContact::getByURL($parent['author-link'], false);
 666                                 if (!empty($profile)) {
 667                                         if (($profile['type'] == 'Group') || ($parent['uri'] == $item['thr-parent'])) {
 668                                                 $data['to'][] = $profile['url'];
 669                                         } else {
 670                                                 $data['cc'][] = $profile['url'];
 671                                         }
 672                                 }
 673                         }
 674                         DBA::close($parents);
 675                 }
 676
 677                 $data['to'] = array_unique($data['to']);
 678                 $data['cc'] = array_unique($data['cc']);
 679                 $data['bcc'] = array_unique($data['bcc']);
 680
 681                 if (($key = array_search($item['author-link'], $data['to'])) !== false) {
 682                         unset($data['to'][$key]);
 683                 }
 684
 685                 if (($key = array_search($item['author-link'], $data['cc'])) !== false) {
 686                         unset($data['cc'][$key]);
 687                 }
 688
 689                 if (($key = array_search($item['author-link'], $data['bcc'])) !== false) {
 690                         unset($data['bcc'][$key]);
 691                 }
 692
 693                 foreach ($data['to'] as $to) {
 694                         if (($key = array_search($to, $data['cc'])) !== false) {
 695                                 unset($data['cc'][$key]);
 696                         }
 697
 698                         if (($key = array_search($to, $data['bcc'])) !== false) {
 699                                 unset($data['bcc'][$key]);
 700                         }
 701                 }
 702
 703                 foreach ($data['cc'] as $cc) {
 704                         if (($key = array_search($cc, $data['bcc'])) !== false) {
 705                                 unset($data['bcc'][$key]);
 706                         }
 707                 }
 708
 709                 $receivers = ['to' => array_values($data['to']), 'cc' => array_values($data['cc']), 'bcc' => array_values($data['bcc'])];
 710
 711                 if (!$blindcopy) {
 712                         unset($receivers['bcc']);
 713                 }
 714
 715                 foreach (['to' => Tag::TO, 'cc' => Tag::CC, 'bcc' => Tag::BCC] as $element => $type) {
 716                         if (!empty($receivers[$element])) {
 717                                 foreach ($receivers[$element] as $receiver) {
 718                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
 719                                                 $name = Receiver::PUBLIC_COLLECTION;
 720                                         } else {
 721                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
 722                                         }
 723                                         Tag::store($item['uri-id'], $type, $name, $receiver);
 724                                 }
 725                         }
 726                 }
 727
 728                 return $receivers;
 729         }
 730
 731         /**
 732          * Check if an inbox is archived
 733          *
 734          * @param string $url Inbox url
 735          *
 736          * @return boolean "true" if inbox is archived
 737          */
 738         public static function archivedInbox($url)
 739         {
 740                 return DBA::exists('inbox-status', ['url' => $url, 'archive' => true]);
 741         }
 742
 743         /**
 744          * Check if a given contact should be delivered via AP
 745          *
 746          * @param array $contact
 747          * @param array $networks
 748          * @return bool
 749          * @throws Exception
 750          */
 751         private static function isAPContact(array $contact, array $networks)
 752         {
 753                 if (in_array($contact['network'], $networks) || ($contact['protocol'] == Protocol::ACTIVITYPUB)) {
 754                         return true;
 755                 }
 756
 757                 return GServer::getProtocol($contact['gsid'] ?? 0) == Post\DeliveryData::ACTIVITYPUB;
 758         }
 759
 760         /**
 761          * Fetches a list of inboxes of followers of a given user
 762          *
 763          * @param integer $uid      User ID
 764          * @param boolean $personal fetch personal inboxes
 765          * @param boolean $all_ap   Retrieve all AP enabled inboxes
 766          *
 767          * @return array of follower inboxes
 768          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 769          * @throws \ImagickException
 770          */
 771         public static function fetchTargetInboxesforUser($uid, $personal = false, bool $all_ap = false)
 772         {
 773                 $inboxes = [];
 774
 775                 $isforum = false;
 776
 777                 if (!empty($item['uid'])) {
 778                         $profile = User::getOwnerDataById($item['uid']);
 779                         if (!empty($profile)) {
 780                                 $isforum = $profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY;
 781                         }
 782                 }
 783
 784                 if (DI::config()->get('debug', 'total_ap_delivery') || $all_ap) {
 785                         // Will be activated in a later step
 786                         $networks = Protocol::FEDERATED;
 787                 } else {
 788                         // For now only send to these contacts:
 789                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 790                 }
 791
 792                 $condition = ['uid' => $uid, 'archive' => false, 'pending' => false, 'blocked' => false, 'network' => Protocol::FEDERATED];
 793
 794                 if (!empty($uid)) {
 795                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
 796                 }
 797
 798                 $contacts = DBA::select('contact', ['id', 'url', 'network', 'protocol', 'gsid'], $condition);
 799                 while ($contact = DBA::fetch($contacts)) {
 800                         if (!self::isAPContact($contact, $networks)) {
 801                                 continue;
 802                         }
 803
 804                         if ($isforum && ($contact['network'] == Protocol::DFRN)) {
 805                                 continue;
 806                         }
 807
 808                         if (Network::isUrlBlocked($contact['url'])) {
 809                                 continue;
 810                         }
 811
 812                         $profile = APContact::getByURL($contact['url'], false);
 813                         if (!empty($profile)) {
 814                                 if (empty($profile['sharedinbox']) || $personal || Contact::isLocal($contact['url'])) {
 815                                         $target = $profile['inbox'];
 816                                 } else {
 817                                         $target = $profile['sharedinbox'];
 818                                 }
 819                                 if (!self::archivedInbox($target)) {
 820                                         $inboxes[$target][] = $contact['id'];
 821                                 }
 822                         }
 823                 }
 824                 DBA::close($contacts);
 825
 826                 return $inboxes;
 827         }
 828
 829         /**
 830          * Fetches an array of inboxes for the given item and user
 831          *
 832          * @param array   $item     Item array
 833          * @param integer $uid      User ID
 834          * @param boolean $personal fetch personal inboxes
 835          * @param integer $last_id  Last item id for adding receivers
 836          * @return array with inboxes
 837          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 838          * @throws \ImagickException
 839          */
 840         public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0)
 841         {
 842                 $permissions = self::createPermissionBlockForItem($item, true, $last_id);
 843                 if (empty($permissions)) {
 844                         return [];
 845                 }
 846
 847                 $inboxes = [];
 848
 849                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
 850                         $item_profile = APContact::getByURL($item['author-link'], false);
 851                 } else {
 852                         $item_profile = APContact::getByURL($item['owner-link'], false);
 853                 }
 854
 855                 if (empty($item_profile)) {
 856                         return [];
 857                 }
 858
 859                 $profile_uid = User::getIdForURL($item_profile['url']);
 860
 861                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 862                         if (empty($permissions[$element])) {
 863                                 continue;
 864                         }
 865
 866                         $blindcopy = in_array($element, ['bto', 'bcc']);
 867
 868                         foreach ($permissions[$element] as $receiver) {
 869                                 if (empty($receiver) || Network::isUrlBlocked($receiver)) {
 870                                         continue;
 871                                 }
 872
 873                                 if ($item_profile && ($receiver == $item_profile['followers']) && ($uid == $profile_uid)) {
 874                                         $inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal, self::isAPPost($last_id)));
 875                                 } else {
 876                                         $profile = APContact::getByURL($receiver, false);
 877                                         if (!empty($profile)) {
 878                                                 $contact = Contact::getByURLForUser($receiver, $uid, false, ['id']);
 879
 880                                                 if (empty($profile['sharedinbox']) || $personal || $blindcopy || Contact::isLocal($receiver)) {
 881                                                         $target = $profile['inbox'];
 882                                                 } else {
 883                                                         $target = $profile['sharedinbox'];
 884                                                 }
 885                                                 if (!self::archivedInbox($target)) {
 886                                                         $inboxes[$target][] = $contact['id'] ?? 0;
 887                                                 }
 888                                         }
 889                                 }
 890                         }
 891                 }
 892
 893                 return $inboxes;
 894         }
 895
 896         /**
 897          * Creates an array in the structure of the item table for a given mail id
 898          *
 899          * @param integer $mail_id
 900          *
 901          * @return array
 902          * @throws \Exception
 903          */
 904         public static function ItemArrayFromMail($mail_id, $use_title = false)
 905         {
 906                 $mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
 907                 if (!DBA::isResult($mail)) {
 908                         return [];
 909                 }
 910
 911                 $reply = DBA::selectFirst('mail', ['uri', 'uri-id', 'from-url'], ['parent-uri' => $mail['parent-uri'], 'reply' => false]);
 912                 if (!DBA::isResult($reply)) {
 913                         $reply = $mail;
 914                 }
 915
 916                 // Making the post more compatible for Mastodon by:
 917                 // - Making it a note and not an article (no title)
 918                 // - Moving the title into the "summary" field that is used as a "content warning"
 919
 920                 if (!$use_title) {
 921                         $mail['body']         = '[abstract]' . $mail['title'] . "[/abstract]\n" . $mail['body'];
 922                         $mail['title']        = '';
 923                 }
 924
 925                 $mail['content-warning']  = '';
 926                 $mail['author-link']      = $mail['owner-link'] = $mail['from-url'];
 927                 $mail['owner-id']         = $mail['author-id'];
 928                 $mail['allow_cid']        = '<'.$mail['contact-id'].'>';
 929                 $mail['allow_gid']        = '';
 930                 $mail['deny_cid']         = '';
 931                 $mail['deny_gid']         = '';
 932                 $mail['private']          = Item::PRIVATE;
 933                 $mail['deleted']          = false;
 934                 $mail['edited']           = $mail['created'];
 935                 $mail['plink']            = DI::baseUrl() . '/message/' . $mail['id'];
 936                 $mail['parent-uri']       = $reply['uri'];
 937                 $mail['parent-uri-id']    = $reply['uri-id'];
 938                 $mail['parent-author-id'] = Contact::getIdForURL($reply['from-url'], 0, false);
 939                 $mail['gravity']          = ($mail['reply'] ? GRAVITY_COMMENT: GRAVITY_PARENT);
 940                 $mail['event-type']       = '';
 941                 $mail['language']         = '';
 942                 $mail['parent']           = 0;
 943
 944                 return $mail;
 945         }
 946
 947         /**
 948          * Creates an activity array for a given mail id
 949          *
 950          * @param integer $mail_id
 951          * @param boolean $object_mode Is the activity item is used inside another object?
 952          *
 953          * @return array of activity
 954          * @throws \Exception
 955          */
 956         public static function createActivityFromMail($mail_id, $object_mode = false)
 957         {
 958                 $mail = self::ItemArrayFromMail($mail_id);
 959                 if (empty($mail)) {
 960                         return [];
 961                 }
 962                 $object = self::createNote($mail);
 963
 964                 if (!$object_mode) {
 965                         $data = ['@context' => ActivityPub::CONTEXT];
 966                 } else {
 967                         $data = [];
 968                 }
 969
 970                 $data['id'] = $mail['uri'] . '/Create';
 971                 $data['type'] = 'Create';
 972                 $data['actor'] = $mail['author-link'];
 973                 $data['published'] = DateTimeFormat::utc($mail['created'] . '+00:00', DateTimeFormat::ATOM);
 974                 $data['instrument'] = self::getService();
 975                 $data = array_merge($data, self::createPermissionBlockForItem($mail, true));
 976
 977                 if (empty($data['to']) && !empty($data['cc'])) {
 978                         $data['to'] = $data['cc'];
 979                 }
 980
 981                 if (empty($data['to']) && !empty($data['bcc'])) {
 982                         $data['to'] = $data['bcc'];
 983                 }
 984
 985                 unset($data['cc']);
 986                 unset($data['bcc']);
 987
 988                 $object['to'] = $data['to'];
 989                 $object['tag'] = [['type' => 'Mention', 'href' => $object['to'][0], 'name' => '']];
 990
 991                 unset($object['cc']);
 992                 unset($object['bcc']);
 993
 994                 $data['directMessage'] = true;
 995
 996                 $data['object'] = $object;
 997
 998                 $owner = User::getOwnerDataById($mail['uid']);
 999
1000                 if (!$object_mode && !empty($owner)) {
1001                         return LDSignature::sign($data, $owner);
1002                 } else {
1003                         return $data;
1004                 }
1005         }
1006
1007         /**
1008          * Returns the activity type of a given item
1009          *
1010          * @param array $item
1011          *
1012          * @return string with activity type
1013          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1014          * @throws \ImagickException
1015          */
1016         private static function getTypeOfItem($item)
1017         {
1018                 $reshared = false;
1019
1020                 // Only check for a reshare, if it is a real reshare and no quoted reshare
1021                 if (strpos($item['body'], "[share") === 0) {
1022                         $announce = self::getAnnounceArray($item);
1023                         $reshared = !empty($announce);
1024                 }
1025
1026                 if ($reshared) {
1027                         $type = 'Announce';
1028                 } elseif ($item['verb'] == Activity::POST) {
1029                         if ($item['created'] == $item['edited']) {
1030                                 $type = 'Create';
1031                         } else {
1032                                 $type = 'Update';
1033                         }
1034                 } elseif ($item['verb'] == Activity::LIKE) {
1035                         $type = 'Like';
1036                 } elseif ($item['verb'] == Activity::DISLIKE) {
1037                         $type = 'Dislike';
1038                 } elseif ($item['verb'] == Activity::ATTEND) {
1039                         $type = 'Accept';
1040                 } elseif ($item['verb'] == Activity::ATTENDNO) {
1041                         $type = 'Reject';
1042                 } elseif ($item['verb'] == Activity::ATTENDMAYBE) {
1043                         $type = 'TentativeAccept';
1044                 } elseif ($item['verb'] == Activity::FOLLOW) {
1045                         $type = 'Follow';
1046                 } elseif ($item['verb'] == Activity::TAG) {
1047                         $type = 'Add';
1048                 } elseif ($item['verb'] == Activity::ANNOUNCE) {
1049                         $type = 'Announce';
1050                 } else {
1051                         $type = '';
1052                 }
1053
1054                 return $type;
1055         }
1056
1057         /**
1058          * Creates the activity or fetches it from the cache
1059          *
1060          * @param integer $item_id
1061          * @param boolean $force Force new cache entry
1062          *
1063          * @return array with the activity
1064          * @throws \Exception
1065          */
1066         public static function createCachedActivityFromItem($item_id, $force = false)
1067         {
1068                 $cachekey = 'APDelivery:createActivity:' . $item_id;
1069
1070                 if (!$force) {
1071                         $data = DI::cache()->get($cachekey);
1072                         if (!is_null($data)) {
1073                                 return $data;
1074                         }
1075                 }
1076
1077                 $data = self::createActivityFromItem($item_id);
1078
1079                 DI::cache()->set($cachekey, $data, Duration::QUARTER_HOUR);
1080                 return $data;
1081         }
1082
1083         /**
1084          * Creates an activity array for a given item id
1085          *
1086          * @param integer $item_id
1087          * @param boolean $object_mode Is the activity item is used inside another object?
1088          *
1089          * @return false|array
1090          * @throws \Exception
1091          */
1092         public static function createActivityFromItem(int $item_id, bool $object_mode = false)
1093         {
1094                 Logger::info('Fetching activity', ['item' => $item_id]);
1095                 $item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
1096                 if (!DBA::isResult($item)) {
1097                         return false;
1098                 }
1099
1100                 if (empty($item['uri-id'])) {
1101                         Logger::warning('Item without uri-id', ['item' => $item]);
1102                         return false;
1103                 }
1104
1105                 if (!$item['deleted']) {
1106                         $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
1107                         $conversation = DBA::selectFirst('conversation', ['source'], $condition);
1108                         if (!$item['origin'] && DBA::isResult($conversation)) {
1109                                 $data = json_decode($conversation['source'], true);
1110                                 if (!empty($data['type'])) {
1111                                         if (in_array($data['type'], ['Create', 'Update'])) {
1112                                                 if ($object_mode) {
1113                                                         unset($data['@context']);
1114                                                         unset($data['signature']);
1115                                                 }
1116                                                 Logger::info('Return stored conversation', ['item' => $item_id]);
1117                                                 return $data;
1118                                         } elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
1119                                                 if (!empty($data['@context'])) {
1120                                                         $context = $data['@context'];
1121                                                         unset($data['@context']);
1122                                                 }
1123                                                 unset($data['actor']);
1124                                                 $object = $data;
1125                                         }
1126                                 }
1127                         }
1128                 }
1129
1130                 $type = self::getTypeOfItem($item);
1131
1132                 if (!$object_mode) {
1133                         $data = ['@context' => $context ?? ActivityPub::CONTEXT];
1134
1135                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
1136                                 $type = 'Undo';
1137                         } elseif ($item['deleted']) {
1138                                 $type = 'Delete';
1139                         }
1140                 } else {
1141                         $data = [];
1142                 }
1143
1144                 if ($type == 'Delete') {
1145                         $data['id'] = Item::newURI($item['uid'], $item['guid']) . '/' . $type;;
1146                 } elseif (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
1147                         $data['id'] = $item['uri'];
1148                 } else {
1149                         $data['id'] = $item['uri'] . '/' . $type;
1150                 }
1151
1152                 $data['type'] = $type;
1153
1154                 if (($type != 'Announce') || ($item['gravity'] != GRAVITY_PARENT)) {
1155                         $data['actor'] = $item['author-link'];
1156                 } else {
1157                         $data['actor'] = $item['owner-link'];
1158                 }
1159
1160                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1161
1162                 $data['instrument'] = self::getService();
1163
1164                 $data = array_merge($data, self::createPermissionBlockForItem($item, false));
1165
1166                 if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
1167                         $data['object'] = $object ?? self::createNote($item);
1168                 } elseif ($data['type'] == 'Add') {
1169                         $data = self::createAddTag($item, $data);
1170                 } elseif ($data['type'] == 'Announce') {
1171                         if ($item['verb'] == ACTIVITY::ANNOUNCE) {
1172                                 $data['object'] = $item['thr-parent'];
1173                         } else {
1174                                 $data = self::createAnnounce($item, $data);
1175                         }
1176                 } elseif ($data['type'] == 'Follow') {
1177                         $data['object'] = $item['parent-uri'];
1178                 } elseif ($data['type'] == 'Undo') {
1179                         $data['object'] = self::createActivityFromItem($item_id, true);
1180                 } else {
1181                         $data['diaspora:guid'] = $item['guid'];
1182                         if (!empty($item['signed_text'])) {
1183                                 $data['diaspora:like'] = $item['signed_text'];
1184                         }
1185                         $data['object'] = $item['thr-parent'];
1186                 }
1187
1188                 if (!empty($item['contact-uid'])) {
1189                         $uid = $item['contact-uid'];
1190                 } else {
1191                         $uid = $item['uid'];
1192                 }
1193
1194                 $owner = User::getOwnerDataById($uid);
1195
1196                 Logger::info('Fetched activity', ['item' => $item_id, 'uid' => $uid]);
1197
1198                 // We don't sign if we aren't the actor. This is important for relaying content especially for forums
1199                 if (!$object_mode && !empty($owner) && ($data['actor'] == $owner['url'])) {
1200                         return LDSignature::sign($data, $owner);
1201                 } else {
1202                         return $data;
1203                 }
1204
1205                 /// @todo Create "conversation" entry
1206         }
1207
1208         /**
1209          * Creates a location entry for a given item array
1210          *
1211          * @param array $item
1212          *
1213          * @return array with location array
1214          */
1215         private static function createLocation($item)
1216         {
1217                 $location = ['type' => 'Place'];
1218
1219                 if (!empty($item['location'])) {
1220                         $location['name'] = $item['location'];
1221                 }
1222
1223                 $coord = [];
1224
1225                 if (empty($item['coord'])) {
1226                         $coord = Map::getCoordinates($item['location']);
1227                 } else {
1228                         $coords = explode(' ', $item['coord']);
1229                         if (count($coords) == 2) {
1230                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
1231                         }
1232                 }
1233
1234                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
1235                         $location['latitude'] = $coord['lat'];
1236                         $location['longitude'] = $coord['lon'];
1237                 }
1238
1239                 return $location;
1240         }
1241
1242         /**
1243          * Returns a tag array for a given item array
1244          *
1245          * @param array $item
1246          *
1247          * @return array of tags
1248          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1249          */
1250         private static function createTagList($item)
1251         {
1252                 $tags = [];
1253
1254                 $terms = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG, Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1255                 foreach ($terms as $term) {
1256                         if ($term['type'] == Tag::HASHTAG) {
1257                                 $url = DI::baseUrl() . '/search?tag=' . urlencode($term['name']);
1258                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['name']];
1259                         } else {
1260                                 $contact = Contact::getByURL($term['url'], false, ['addr']);
1261                                 if (empty($contact)) {
1262                                         continue;
1263                                 }
1264                                 if (!empty($contact['addr'])) {
1265                                         $mention = '@' . $contact['addr'];
1266                                 } else {
1267                                         $mention = '@' . $term['url'];
1268                                 }
1269
1270                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
1271                         }
1272                 }
1273
1274                 $announce = self::getAnnounceArray($item);
1275                 // Mention the original author upon commented reshares
1276                 if (!empty($announce['comment'])) {
1277                         $tags[] = ['type' => 'Mention', 'href' => $announce['actor']['url'], 'name' => '@' . $announce['actor']['addr']];
1278                 }
1279
1280                 return $tags;
1281         }
1282
1283         /**
1284          * Adds attachment data to the JSON document
1285          *
1286          * @param array  $item Data of the item that is to be posted
1287          * @param string $type Object type
1288          *
1289          * @return array with attachment data
1290          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1291          */
1292         private static function createAttachmentList($item, $type)
1293         {
1294                 $attachments = [];
1295
1296                 $uriids = [$item['uri-id']];
1297                 $shared = BBCode::fetchShareAttributes($item['body']);
1298                 if (!empty($shared['guid'])) {
1299                         $shared_item = Post::selectFirst(['uri-id'], ['guid' => $shared['guid']]);
1300                         if (!empty($shared_item['uri-id'])) {
1301                                 $uriids[] = $shared_item['uri-id'];
1302                         }
1303                 }
1304
1305                 $urls = [];
1306                 foreach ($uriids as $uriid) {
1307                         foreach (Post\Media::getByURIId($uriid, [Post\Media::AUDIO, Post\Media::IMAGE, Post\Media::VIDEO, Post\Media::DOCUMENT, Post\Media::TORRENT]) as $attachment) {
1308                                 if (in_array($attachment['url'], $urls)) {
1309                                         continue;
1310                                 }
1311                                 $urls[] = $attachment['url'];
1312
1313                                 $attach = ['type' => 'Document',
1314                                         'mediaType' => $attachment['mimetype'],
1315                                         'url' => $attachment['url'],
1316                                         'name' => $attachment['description']];
1317
1318                                 if (!empty($attachment['height'])) {
1319                                         $attach['height'] = $attachment['height'];
1320                                 }
1321
1322                                 if (!empty($attachment['width'])) {
1323                                         $attach['width'] = $attachment['width'];
1324                                 }
1325
1326                                 if (!empty($attachment['preview'])) {
1327                                         $attach['image'] = $attachment['preview'];
1328                                 }
1329
1330                                 $attachments[] = $attach;
1331                         }
1332                 }
1333
1334                 return $attachments;
1335         }
1336
1337         /**
1338          * Callback function to replace a Friendica style mention in a mention for a summary
1339          *
1340          * @param array $match Matching values for the callback
1341          * @return string Replaced mention
1342          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1343          */
1344         private static function mentionAddrCallback($match)
1345         {
1346                 if (empty($match[1])) {
1347                         return '';
1348                 }
1349
1350                 $data = Contact::getByURL($match[1], false, ['addr']);
1351                 if (empty($data['addr'])) {
1352                         return $match[0];
1353                 }
1354
1355                 return '@' . $data['addr'];
1356         }
1357
1358         /**
1359          * Remove image elements since they are added as attachment
1360          *
1361          * @param string $body
1362          *
1363          * @return string with removed images
1364          */
1365         private static function removePictures($body)
1366         {
1367                 // Simplify image codes
1368                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
1369                 $body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
1370
1371                 // Now remove local links
1372                 $body = preg_replace_callback(
1373                         '/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi',
1374                         function ($match) {
1375                                 // We remove the link when it is a link to a local photo page
1376                                 if (Photo::isLocalPage($match[1])) {
1377                                         return '';
1378                                 }
1379                                 // otherwise we just return the link
1380                                 return '[url]' . $match[1] . '[/url]';
1381                         },
1382                         $body
1383                 );
1384
1385                 // Remove all pictures
1386                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '', $body);
1387
1388                 return $body;
1389         }
1390
1391         /**
1392          * Fetches the "context" value for a givem item array from the "conversation" table
1393          *
1394          * @param array $item
1395          *
1396          * @return string with context url
1397          * @throws \Exception
1398          */
1399         private static function fetchContextURLForItem($item)
1400         {
1401                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
1402                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
1403                         $context_uri = $conversation['conversation-href'];
1404                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
1405                         $context_uri = $conversation['conversation-uri'];
1406                 } else {
1407                         $context_uri = $item['parent-uri'] . '#context';
1408                 }
1409                 return $context_uri;
1410         }
1411
1412         /**
1413          * Returns if the post contains sensitive content ("nsfw")
1414          *
1415          * @param integer $uri_id
1416          *
1417          * @return boolean
1418          * @throws \Exception
1419          */
1420         private static function isSensitive($uri_id)
1421         {
1422                 return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw', 'type' => Tag::HASHTAG]);
1423         }
1424
1425         /**
1426          * Creates event data
1427          *
1428          * @param array $item
1429          *
1430          * @return array with the event data
1431          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1432          */
1433         private static function createEvent($item)
1434         {
1435                 $event = [];
1436                 $event['name'] = $item['event-summary'];
1437                 $event['content'] = BBCode::convertForUriId($item['uri-id'], $item['event-desc'], BBCode::ACTIVITYPUB);
1438                 $event['startTime'] = DateTimeFormat::utc($item['event-start'], 'c');
1439
1440                 if (!$item['event-nofinish']) {
1441                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'], 'c');
1442                 }
1443
1444                 if (!empty($item['event-location'])) {
1445                         $item['location'] = $item['event-location'];
1446                         $event['location'] = self::createLocation($item);
1447                 }
1448
1449                 // 2021.12: Backward compatibility value, all the events now "adjust" to the viewer timezone
1450                 $event['dfrn:adjust'] = true;
1451
1452                 return $event;
1453         }
1454
1455         /**
1456          * Creates a note/article object array
1457          *
1458          * @param array $item
1459          *
1460          * @return array with the object data
1461          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1462          * @throws \ImagickException
1463          */
1464         public static function createNote($item)
1465         {
1466                 if (empty($item)) {
1467                         return [];
1468                 }
1469
1470                 // We are treating posts differently when they are directed to a community.
1471                 // This is done to better support Lemmy. Most of the changes should work with other systems as well.
1472                 // But to not risk compatibility issues we currently perform the changes only for communities.
1473                 if ($item['gravity'] == GRAVITY_PARENT) {
1474                         $isCommunityPost = !empty(Tag::getByURIId($item['uri-id'], [Tag::EXCLUSIVE_MENTION]));
1475                         $links = Post\Media::getByURIId($item['uri-id'], [Post\Media::HTML]);
1476                         if ($isCommunityPost && (count($links) == 1)) {
1477                                 $link = $links[0]['url'];
1478                         }
1479                 } else {
1480                         $isCommunityPost = false;
1481                 }
1482
1483                 if ($item['event-type'] == 'event') {
1484                         $type = 'Event';
1485                 } elseif (!empty($item['title'])) {
1486                         if (!$isCommunityPost || empty($link)) {
1487                                 $type = 'Article';
1488                         } else {
1489                                 // "Page" is used by Lemmy for posts that contain an external link
1490                                 $type = 'Page';
1491                         }
1492                 } else {
1493                         $type = 'Note';
1494                 }
1495
1496                 if ($item['deleted']) {
1497                         $type = 'Tombstone';
1498                 }
1499
1500                 $data = [];
1501                 $data['id'] = $item['uri'];
1502                 $data['type'] = $type;
1503
1504                 if ($item['deleted']) {
1505                         return $data;
1506                 }
1507
1508                 $data['summary'] = BBCode::toPlaintext(BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB));
1509
1510                 if ($item['uri'] != $item['thr-parent']) {
1511                         $data['inReplyTo'] = $item['thr-parent'];
1512                 } else {
1513                         $data['inReplyTo'] = null;
1514                 }
1515
1516                 $data['diaspora:guid'] = $item['guid'];
1517                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1518
1519                 if ($item['created'] != $item['edited']) {
1520                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1521                 }
1522
1523                 $data['url'] = $link ?? $item['plink'];
1524                 $data['attributedTo'] = $item['author-link'];
1525                 $data['sensitive'] = self::isSensitive($item['uri-id']);
1526                 $data['context'] = self::fetchContextURLForItem($item);
1527
1528                 if (!empty($item['title'])) {
1529                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1530                 }
1531
1532                 $permission_block = self::createPermissionBlockForItem($item, false);
1533
1534                 $body = $item['body'];
1535
1536                 if ($type == 'Note') {
1537                         $body = $item['raw-body'] ?? self::removePictures($body);
1538                 }
1539
1540                 /**
1541                  * @todo Improve the automated summary
1542                  * This part is currently deactivated. The automated summary seems to be more
1543                  * confusing than helping. But possibly we will find a better way.
1544                  * So the code is left here for now as a reminder
1545                  *
1546                  * } elseif (($type == 'Article') && empty($data['summary'])) {
1547                  *              $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1548                  *              $summary = preg_replace_callback($regexp, ['self', 'mentionAddrCallback'], $body);
1549                  *              $data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($summary), 1000));
1550                  * }
1551                  */
1552
1553                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1554                         $body = self::prependMentions($body, $item['uri-id'], $item['author-link']);
1555                 }
1556
1557                 if ($type == 'Event') {
1558                         $data = array_merge($data, self::createEvent($item));
1559                 } else {
1560                         if ($isCommunityPost) {
1561                                 // For community posts we remove the visible "!user@domain.tld".
1562                                 // This improves the look at systems like Lemmy.
1563                                 // Also in the future we should control the community delivery via other methods.
1564                                 $body = preg_replace("/!\[url\=[^\[\]]*\][^\[\]]*\[\/url\]/ism", '', $body);
1565                         }
1566
1567                         if ($type == 'Page') {
1568                                 // When we transmit "Page" posts we have to remove the attachment.
1569                                 // The attachment contains the link that we already transmit in the "url" field.
1570                                 $body = preg_replace("/\s*\[attachment .*?\].*?\[\/attachment\]\s*/ism", '', $body);
1571                         }
1572
1573                         $body = BBCode::setMentionsToNicknames($body);
1574
1575                         $data['content'] = BBCode::convertForUriId($item['uri-id'], $body, BBCode::ACTIVITYPUB);
1576                 }
1577
1578                 // The regular "content" field does contain a minimized HTML. This is done since systems like
1579                 // Mastodon has got problems with - for example - embedded pictures.
1580                 // The contentMap does contain the unmodified HTML.
1581                 $language = self::getLanguage($item);
1582                 if (!empty($language)) {
1583                         $richbody = BBCode::setMentionsToNicknames($item['body'] ?? '');
1584                         $richbody = BBCode::removeAttachment($richbody);
1585
1586                         $data['contentMap'][$language] = BBCode::convertForUriId($item['uri-id'], $richbody, BBCode::EXTERNAL);
1587                 }
1588
1589                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1590
1591                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1592                         $data['diaspora:comment'] = $item['signed_text'];
1593                 }
1594
1595                 $data['attachment'] = self::createAttachmentList($item, $type);
1596                 $data['tag'] = self::createTagList($item);
1597
1598                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1599                         $data['location'] = self::createLocation($item);
1600                 }
1601
1602                 if (!empty($item['app'])) {
1603                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1604                 }
1605
1606                 $data = array_merge($data, $permission_block);
1607
1608                 return $data;
1609         }
1610
1611         /**
1612          * Fetches the language from the post, the user or the system.
1613          *
1614          * @param array $item
1615          *
1616          * @return string language string
1617          */
1618         private static function getLanguage(array $item)
1619         {
1620                 // Try to fetch the language from the post itself
1621                 if (!empty($item['language'])) {
1622                         $languages = array_keys(json_decode($item['language'], true));
1623                         if (!empty($languages[0])) {
1624                                 return $languages[0];
1625                         }
1626                 }
1627
1628                 // Otherwise use the user's language
1629                 if (!empty($item['uid'])) {
1630                         $user = DBA::selectFirst('user', ['language'], ['uid' => $item['uid']]);
1631                         if (!empty($user['language'])) {
1632                                 return $user['language'];
1633                         }
1634                 }
1635
1636                 // And finally just use the system language
1637                 return DI::config()->get('system', 'language');
1638         }
1639
1640         /**
1641          * Creates an an "add tag" entry
1642          *
1643          * @param array $item
1644          * @param array $data activity data
1645          *
1646          * @return array with activity data for adding tags
1647          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1648          * @throws \ImagickException
1649          */
1650         private static function createAddTag($item, $data)
1651         {
1652                 $object = XML::parseString($item['object']);
1653                 $target = XML::parseString($item["target"]);
1654
1655                 $data['diaspora:guid'] = $item['guid'];
1656                 $data['actor'] = $item['author-link'];
1657                 $data['target'] = (string)$target->id;
1658                 $data['summary'] = BBCode::toPlaintext($item['body']);
1659                 $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
1660
1661                 return $data;
1662         }
1663
1664         /**
1665          * Creates an announce object entry
1666          *
1667          * @param array $item
1668          * @param array $data activity data
1669          *
1670          * @return array with activity data
1671          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1672          * @throws \ImagickException
1673          */
1674         private static function createAnnounce($item, $data)
1675         {
1676                 $orig_body = $item['body'];
1677                 $announce = self::getAnnounceArray($item);
1678                 if (empty($announce)) {
1679                         $data['type'] = 'Create';
1680                         $data['object'] = self::createNote($item);
1681                         return $data;
1682                 }
1683
1684                 if (empty($announce['comment'])) {
1685                         // Pure announce, without a quote
1686                         $data['type'] = 'Announce';
1687                         $data['object'] = $announce['object']['uri'];
1688                         return $data;
1689                 }
1690
1691                 // Quote
1692                 $data['type'] = 'Create';
1693                 $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
1694                 $data['object'] = self::createNote($item);
1695
1696                 /// @todo Finally descide how to implement this in AP. This is a possible way:
1697                 $data['object']['attachment'][] = self::createNote($announce['object']);
1698
1699                 $data['object']['source']['content'] = $orig_body;
1700                 return $data;
1701         }
1702
1703         /**
1704          * Return announce related data if the item is an annunce
1705          *
1706          * @param array $item
1707          *
1708          * @return array
1709          */
1710         public static function getAnnounceArray($item)
1711         {
1712                 $reshared = Item::getShareArray($item);
1713                 if (empty($reshared['guid'])) {
1714                         return [];
1715                 }
1716
1717                 $reshared_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['guid' => $reshared['guid']]);
1718                 if (!DBA::isResult($reshared_item)) {
1719                         return [];
1720                 }
1721
1722                 if (!in_array($reshared_item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
1723                         return [];
1724                 }
1725
1726                 $profile = APContact::getByURL($reshared_item['author-link'], false);
1727                 if (empty($profile)) {
1728                         return [];
1729                 }
1730
1731                 return ['object' => $reshared_item, 'actor' => $profile, 'comment' => $reshared['comment']];
1732         }
1733
1734         /**
1735          * Checks if the provided item array is an announce
1736          *
1737          * @param array $item
1738          *
1739          * @return boolean
1740          */
1741         public static function isAnnounce($item)
1742         {
1743                 if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
1744                         return true;
1745                 }
1746
1747                 $announce = self::getAnnounceArray($item);
1748                 if (empty($announce)) {
1749                         return false;
1750                 }
1751
1752                 return empty($announce['comment']);
1753         }
1754
1755         /**
1756          * Creates an activity id for a given contact id
1757          *
1758          * @param integer $cid Contact ID of target
1759          *
1760          * @return bool|string activity id
1761          */
1762         public static function activityIDFromContact($cid)
1763         {
1764                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1765                 if (!DBA::isResult($contact)) {
1766                         return false;
1767                 }
1768
1769                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1770                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1771                 return DI::baseUrl() . '/activity/' . $uuid;
1772         }
1773
1774         /**
1775          * Transmits a contact suggestion to a given inbox
1776          *
1777          * @param integer $uid           User ID
1778          * @param string  $inbox         Target inbox
1779          * @param integer $suggestion_id Suggestion ID
1780          *
1781          * @return boolean was the transmission successful?
1782          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1783          */
1784         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1785         {
1786                 $owner = User::getOwnerDataById($uid);
1787
1788                 $suggestion = DI::fsuggest()->selectOneById($suggestion_id);
1789
1790                 $data = ['@context' => ActivityPub::CONTEXT,
1791                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1792                         'type' => 'Announce',
1793                         'actor' => $owner['url'],
1794                         'object' => $suggestion->url,
1795                         'content' => $suggestion->note,
1796                         'instrument' => self::getService(),
1797                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1798                         'cc' => []];
1799
1800                 $signed = LDSignature::sign($data, $owner);
1801
1802                 Logger::info('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1803                 return HTTPSignature::transmit($signed, $inbox, $uid);
1804         }
1805
1806         /**
1807          * Transmits a profile relocation to a given inbox
1808          *
1809          * @param integer $uid   User ID
1810          * @param string  $inbox Target inbox
1811          *
1812          * @return boolean was the transmission successful?
1813          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1814          */
1815         public static function sendProfileRelocation($uid, $inbox)
1816         {
1817                 $owner = User::getOwnerDataById($uid);
1818
1819                 $data = ['@context' => ActivityPub::CONTEXT,
1820                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1821                         'type' => 'dfrn:relocate',
1822                         'actor' => $owner['url'],
1823                         'object' => $owner['url'],
1824                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1825                         'instrument' => self::getService(),
1826                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1827                         'cc' => []];
1828
1829                 $signed = LDSignature::sign($data, $owner);
1830
1831                 Logger::info('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1832                 return HTTPSignature::transmit($signed, $inbox, $uid);
1833         }
1834
1835         /**
1836          * Transmits a profile deletion to a given inbox
1837          *
1838          * @param integer $uid   User ID
1839          * @param string  $inbox Target inbox
1840          *
1841          * @return boolean was the transmission successful?
1842          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1843          */
1844         public static function sendProfileDeletion($uid, $inbox)
1845         {
1846                 $owner = User::getOwnerDataById($uid);
1847
1848                 if (empty($owner)) {
1849                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1850                         return false;
1851                 }
1852
1853                 if (empty($owner['uprvkey'])) {
1854                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1855                         return false;
1856                 }
1857
1858                 $data = ['@context' => ActivityPub::CONTEXT,
1859                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1860                         'type' => 'Delete',
1861                         'actor' => $owner['url'],
1862                         'object' => $owner['url'],
1863                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1864                         'instrument' => self::getService(),
1865                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1866                         'cc' => []];
1867
1868                 $signed = LDSignature::sign($data, $owner);
1869
1870                 Logger::info('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1871                 return HTTPSignature::transmit($signed, $inbox, $uid);
1872         }
1873
1874         /**
1875          * Transmits a profile change to a given inbox
1876          *
1877          * @param integer $uid   User ID
1878          * @param string  $inbox Target inbox
1879          *
1880          * @return boolean was the transmission successful?
1881          * @throws HTTPException\InternalServerErrorException
1882          * @throws HTTPException\NotFoundException
1883          * @throws \ImagickException
1884          */
1885         public static function sendProfileUpdate(int $uid, string $inbox): bool
1886         {
1887                 $owner = User::getOwnerDataById($uid);
1888                 $profile = APContact::getByURL($owner['url']);
1889
1890                 $data = ['@context' => ActivityPub::CONTEXT,
1891                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1892                         'type' => 'Update',
1893                         'actor' => $owner['url'],
1894                         'object' => self::getProfile($uid),
1895                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1896                         'instrument' => self::getService(),
1897                         'to' => [$profile['followers']],
1898                         'cc' => []];
1899
1900                 $signed = LDSignature::sign($data, $owner);
1901
1902                 Logger::info('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1903                 return HTTPSignature::transmit($signed, $inbox, $uid);
1904         }
1905
1906         /**
1907          * Transmits a given activity to a target
1908          *
1909          * @param string  $activity Type name
1910          * @param string  $target   Target profile
1911          * @param integer $uid      User ID
1912          * @return bool
1913          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1914          * @throws \ImagickException
1915          * @throws \Exception
1916          */
1917         public static function sendActivity($activity, $target, $uid, $id = '')
1918         {
1919                 $profile = APContact::getByURL($target);
1920                 if (empty($profile['inbox'])) {
1921                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1922                         return;
1923                 }
1924
1925                 $owner = User::getOwnerDataById($uid);
1926
1927                 if (empty($id)) {
1928                         $id = DI::baseUrl() . '/activity/' . System::createGUID();
1929                 }
1930
1931                 $data = ['@context' => ActivityPub::CONTEXT,
1932                         'id' => $id,
1933                         'type' => $activity,
1934                         'actor' => $owner['url'],
1935                         'object' => $profile['url'],
1936                         'instrument' => self::getService(),
1937                         'to' => [$profile['url']]];
1938
1939                 Logger::info('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid);
1940
1941                 $signed = LDSignature::sign($data, $owner);
1942                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1943         }
1944
1945         /**
1946          * Transmits a "follow object" activity to a target
1947          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
1948          *
1949          * @param string  $object Object URL
1950          * @param string  $target Target profile
1951          * @param integer $uid    User ID
1952          * @return bool
1953          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1954          * @throws \ImagickException
1955          * @throws \Exception
1956          */
1957         public static function sendFollowObject($object, $target, $uid = 0)
1958         {
1959                 $profile = APContact::getByURL($target);
1960                 if (empty($profile['inbox'])) {
1961                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1962                         return;
1963                 }
1964
1965                 if (empty($uid)) {
1966                         // Fetch the list of administrators
1967                         $admin_mail = explode(',', str_replace(' ', '', DI::config()->get('config', 'admin_email')));
1968
1969                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
1970                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
1971                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
1972                         $uid = $first_user['uid'];
1973                 }
1974
1975                 $condition = ['verb' => Activity::FOLLOW, 'uid' => 0, 'parent-uri' => $object,
1976                         'author-id' => Contact::getPublicIdByUserId($uid)];
1977                 if (Post::exists($condition)) {
1978                         Logger::info('Follow for ' . $object . ' for user ' . $uid . ' does already exist.');
1979                         return false;
1980                 }
1981
1982                 $owner = User::getOwnerDataById($uid);
1983
1984                 $data = ['@context' => ActivityPub::CONTEXT,
1985                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1986                         'type' => 'Follow',
1987                         'actor' => $owner['url'],
1988                         'object' => $object,
1989                         'instrument' => self::getService(),
1990                         'to' => [$profile['url']]];
1991
1992                 Logger::info('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid);
1993
1994                 $signed = LDSignature::sign($data, $owner);
1995                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1996         }
1997
1998         /**
1999          * Transmit a message that the contact request had been accepted
2000          *
2001          * @param string  $target Target profile
2002          * @param         $id
2003          * @param integer $uid    User ID
2004          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2005          * @throws \ImagickException
2006          */
2007         public static function sendContactAccept($target, $id, $uid)
2008         {
2009                 $profile = APContact::getByURL($target);
2010                 if (empty($profile['inbox'])) {
2011                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2012                         return;
2013                 }
2014
2015                 $owner = User::getOwnerDataById($uid);
2016                 $data = ['@context' => ActivityPub::CONTEXT,
2017                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2018                         'type' => 'Accept',
2019                         'actor' => $owner['url'],
2020                         'object' => [
2021                                 'id' => (string)$id,
2022                                 'type' => 'Follow',
2023                                 'actor' => $profile['url'],
2024                                 'object' => $owner['url']
2025                         ],
2026                         'instrument' => self::getService(),
2027                         'to' => [$profile['url']]];
2028
2029                 Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2030
2031                 $signed = LDSignature::sign($data, $owner);
2032                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2033         }
2034
2035         /**
2036          * Reject a contact request or terminates the contact relation
2037          *
2038          * @param string  $target Target profile
2039          * @param         $id
2040          * @param integer $uid    User ID
2041          * @return bool Operation success
2042          * @throws HTTPException\InternalServerErrorException
2043          * @throws \ImagickException
2044          */
2045         public static function sendContactReject($target, $id, $uid): bool
2046         {
2047                 $profile = APContact::getByURL($target);
2048                 if (empty($profile['inbox'])) {
2049                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2050                         return false;
2051                 }
2052
2053                 $owner = User::getOwnerDataById($uid);
2054                 $data = ['@context' => ActivityPub::CONTEXT,
2055                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2056                         'type' => 'Reject',
2057                         'actor' => $owner['url'],
2058                         'object' => [
2059                                 'id' => (string)$id,
2060                                 'type' => 'Follow',
2061                                 'actor' => $profile['url'],
2062                                 'object' => $owner['url']
2063                         ],
2064                         'instrument' => self::getService(),
2065                         'to' => [$profile['url']]];
2066
2067                 Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2068
2069                 $signed = LDSignature::sign($data, $owner);
2070                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2071         }
2072
2073         /**
2074          * Transmits a message that we don't want to follow this contact anymore
2075          *
2076          * @param string  $target Target profile
2077          * @param integer $uid    User ID
2078          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2079          * @throws \ImagickException
2080          * @throws \Exception
2081          * @return bool success
2082          */
2083         public static function sendContactUndo($target, $cid, $uid)
2084         {
2085                 $profile = APContact::getByURL($target);
2086                 if (empty($profile['inbox'])) {
2087                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2088                         return false;
2089                 }
2090
2091                 $object_id = self::activityIDFromContact($cid);
2092                 if (empty($object_id)) {
2093                         return false;
2094                 }
2095
2096                 $id = DI::baseUrl() . '/activity/' . System::createGUID();
2097
2098                 $owner = User::getOwnerDataById($uid);
2099                 $data = ['@context' => ActivityPub::CONTEXT,
2100                         'id' => $id,
2101                         'type' => 'Undo',
2102                         'actor' => $owner['url'],
2103                         'object' => ['id' => $object_id, 'type' => 'Follow',
2104                                 'actor' => $owner['url'],
2105                                 'object' => $profile['url']],
2106                         'instrument' => self::getService(),
2107                         'to' => [$profile['url']]];
2108
2109                 Logger::info('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2110
2111                 $signed = LDSignature::sign($data, $owner);
2112                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2113         }
2114
2115         private static function prependMentions($body, int $uriid, string $authorLink)
2116         {
2117                 $mentions = [];
2118
2119                 foreach (Tag::getByURIId($uriid, [Tag::IMPLICIT_MENTION]) as $tag) {
2120                         $profile = Contact::getByURL($tag['url'], false, ['addr', 'contact-type', 'nick']);
2121                         if (!empty($profile['addr'])
2122                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
2123                                 && !strstr($body, $profile['addr'])
2124                                 && !strstr($body, $tag['url'])
2125                                 && $tag['url'] !== $authorLink
2126                         ) {
2127                                 $mentions[] = '@[url=' . $tag['url'] . ']' . $profile['nick'] . '[/url]';
2128                         }
2129                 }
2130
2131                 $mentions[] = $body;
2132
2133                 return implode(' ', $mentions);
2134         }
2135 }