src/Protocol/ActivityPub/Transmitter.php

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