src/Protocol/ActivityPub/Transmitter.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2010-2022, the Friendica project
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Protocol\ActivityPub;
  23
  24 use Friendica\Content\Feature;
  25 use Friendica\Content\Text\BBCode;
  26 use Friendica\Core\Cache\Enum\Duration;
  27 use Friendica\Core\Logger;
  28 use Friendica\Core\Protocol;
  29 use Friendica\Core\System;
  30 use Friendica\Database\DBA;
  31 use Friendica\DI;
  32 use Friendica\Model\APContact;
  33 use Friendica\Model\Contact;
  34 use Friendica\Model\Conversation;
  35 use Friendica\Model\GServer;
  36 use Friendica\Model\Item;
  37 use Friendica\Model\Photo;
  38 use Friendica\Model\Post;
  39 use Friendica\Model\Tag;
  40 use Friendica\Model\User;
  41 use Friendica\Network\HTTPException;
  42 use Friendica\Protocol\Activity;
  43 use Friendica\Protocol\ActivityPub;
  44 use Friendica\Protocol\Relay;
  45 use Friendica\Util\DateTimeFormat;
  46 use Friendica\Util\HTTPSignature;
  47 use Friendica\Util\JsonLD;
  48 use Friendica\Util\LDSignature;
  49 use Friendica\Util\Map;
  50 use Friendica\Util\Network;
  51 use Friendica\Util\Strings;
  52 use Friendica\Util\XML;
  53
  54 /**
  55  * ActivityPub Transmitter Protocol class
  56  *
  57  * To-Do:
  58  * @todo Undo Announce
  59  */
  60 class Transmitter
  61 {
  62         /**
  63          * Add relay servers to the list of inboxes
  64          *
  65          * @param array $inboxes
  66          * @return array inboxes with added relay servers
  67          */
  68         public static function addRelayServerInboxes(array $inboxes = [])
  69         {
  70                 foreach (Relay::getList(['inbox']) as $contact) {
  71                         $inboxes[$contact['inbox']] = $contact['inbox'];
  72                 }
  73
  74                 return $inboxes;
  75         }
  76
  77         /**
  78          * Add relay servers to the list of inboxes
  79          *
  80          * @param array $inboxes
  81          * @return array inboxes with added relay servers
  82          */
  83         public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = [])
  84         {
  85                 $item = Post::selectFirst(['uid'], ['id' => $item_id]);
  86                 if (empty($item)) {
  87                         return $inboxes;
  88                 }
  89
  90                 $relays = Relay::getDirectRelayList($item_id);
  91                 if (empty($relays)) {
  92                         return $inboxes;
  93                 }
  94
  95                 foreach ($relays as $relay) {
  96                         $contact = Contact::getByURLForUser($relay['url'], $item['uid'], false, ['id']);
  97                         $inboxes[$relay['batch']][] = $contact['id'] ?? 0;
  98                 }
  99                 return $inboxes;
 100         }
 101
 102         /**
 103          * Subscribe to a relay
 104          *
 105          * @param string $url Subscribe actor url
 106          * @return bool success
 107          */
 108         public static function sendRelayFollow(string $url)
 109         {
 110                 $contact = Contact::getByURL($url);
 111                 if (empty($contact)) {
 112                         return false;
 113                 }
 114
 115                 $activity_id = ActivityPub\Transmitter::activityIDFromContact($contact['id']);
 116                 $success = ActivityPub\Transmitter::sendActivity('Follow', $url, 0, $activity_id);
 117                 if ($success) {
 118                         Contact::update(['rel' => Contact::FRIEND], ['id' => $contact['id']]);
 119                 }
 120
 121                 return $success;
 122         }
 123
 124         /**
 125          * Unsubscribe from a relay
 126          *
 127          * @param string $url   Subscribe actor url
 128          * @param bool   $force Set the relay status as non follower even if unsubscribe hadn't worked
 129          * @return bool success
 130          */
 131         public static function sendRelayUndoFollow(string $url, bool $force = false)
 132         {
 133                 $contact = Contact::getByURL($url);
 134                 if (empty($contact)) {
 135                         return false;
 136                 }
 137
 138                 $success = self::sendContactUndo($url, $contact['id'], 0);
 139                 if ($success || $force) {
 140                         Contact::update(['rel' => Contact::NOTHING], ['id' => $contact['id']]);
 141                 }
 142
 143                 return $success;
 144         }
 145
 146         /**
 147          * Collects a list of contacts of the given owner
 148          *
 149          * @param array     $owner     Owner array
 150          * @param int|array $rel       The relevant value(s) contact.rel should match
 151          * @param string    $module    The name of the relevant AP endpoint module (followers|following)
 152          * @param integer   $page      Page number
 153          * @param string    $requester URL of the requester
 154          *
 155          * @return array of owners
 156          * @throws \Exception
 157          */
 158         public static function getContacts($owner, $rel, $module, $page = null, string $requester = null)
 159         {
 160                 $parameters = [
 161                         'rel' => $rel,
 162                         'uid' => $owner['uid'],
 163                         'self' => false,
 164                         'deleted' => false,
 165                         'hidden' => false,
 166                         'archive' => false,
 167                         'pending' => false,
 168                         'blocked' => false,
 169                 ];
 170
 171                 $condition = DBA::mergeConditions($parameters, ["`url` IN (SELECT `url` FROM `apcontact`)"]);
 172
 173                 $total = DBA::count('contact', $condition);
 174
 175                 $modulePath = '/' . $module . '/';
 176
 177                 $data = ['@context' => ActivityPub::CONTEXT];
 178                 $data['id'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 179                 $data['type'] = 'OrderedCollection';
 180                 $data['totalItems'] = $total;
 181
 182                 // When we hide our friends we will only show the pure number but don't allow more.
 183                 $show_contacts = empty($owner['hide-friends']);
 184
 185                 // Allow fetching the contact list when the requester is part of the list.
 186                 if (($owner['page-flags'] == User::PAGE_FLAGS_PRVGROUP) && !empty($requester)) {
 187                         $show_contacts = DBA::exists('contact', ['nurl' => Strings::normaliseLink($requester), 'uid' => $owner['uid'], 'blocked' => false]);
 188                 }
 189
 190                 if (!$show_contacts) {
 191                         return $data;
 192                 }
 193
 194                 if (empty($page)) {
 195                         $data['first'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=1';
 196                 } else {
 197                         $data['type'] = 'OrderedCollectionPage';
 198                         $list = [];
 199
 200                         $contacts = DBA::select('contact', ['url'], $condition, ['limit' => [($page - 1) * 100, 100]]);
 201                         while ($contact = DBA::fetch($contacts)) {
 202                                 $list[] = $contact['url'];
 203                         }
 204                         DBA::close($contacts);
 205
 206                         if (!empty($list)) {
 207                                 $data['next'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=' . ($page + 1);
 208                         }
 209
 210                         $data['partOf'] = DI::baseUrl() . $modulePath . $owner['nickname'];
 211
 212                         $data['orderedItems'] = $list;
 213                 }
 214
 215                 return $data;
 216         }
 217
 218         /**
 219          * Public posts for the given owner
 220          *
 221          * @param array   $owner     Owner array
 222          * @param integer $page      Page number
 223          * @param string  $requester URL of requesting account
 224          *
 225          * @return array of posts
 226          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 227          * @throws \ImagickException
 228          */
 229         public static function getOutbox($owner, $page = null, $requester = '')
 230         {
 231                 $condition = ['private' => [Item::PUBLIC, Item::UNLISTED]];
 232
 233                 if (!empty($requester)) {
 234                         $requester_id = Contact::getIdForURL($requester, $owner['uid']);
 235                         if (!empty($requester_id)) {
 236                                 $permissionSets = DI::permissionSet()->selectByContactId($requester_id, $owner['uid']);
 237                                 if (!empty($permissionSets)) {
 238                                         $condition = ['psid' => array_merge($permissionSets->column('id'),
 239                                                         [DI::permissionSet()->selectPublicForUser($owner['uid'])])];
 240                                 }
 241                         }
 242                 }
 243
 244                 $condition = array_merge($condition,
 245                         ['uid'           => $owner['uid'],
 246                         'author-id'      => Contact::getIdForURL($owner['url'], 0, false),
 247                         'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
 248                         'network'        => Protocol::FEDERATED,
 249                         'parent-network' => Protocol::FEDERATED,
 250                         'origin'         => true,
 251                         'deleted'        => false,
 252                         'visible'        => true]);
 253
 254                 $count = Post::count($condition);
 255
 256                 $data = ['@context' => ActivityPub::CONTEXT];
 257                 $data['id'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 258                 $data['type'] = 'OrderedCollection';
 259                 $data['totalItems'] = $count;
 260
 261                 if (empty($page)) {
 262                         $data['first'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
 263                 } else {
 264                         $data['type'] = 'OrderedCollectionPage';
 265                         $list = [];
 266
 267                         $items = Post::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
 268                         while ($item = Post::fetch($items)) {
 269                                 $activity = self::createActivityFromItem($item['id'], true);
 270                                 $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
 271
 272                                 // Only list "Create" activity objects here, no reshares
 273                                 if (!empty($activity['object']) && ($activity['type'] == 'Create')) {
 274                                         $list[] = $activity['object'];
 275                                 }
 276                         }
 277                         DBA::close($items);
 278
 279                         if (!empty($list)) {
 280                                 $data['next'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
 281                         }
 282
 283                         $data['partOf'] = DI::baseUrl() . '/outbox/' . $owner['nickname'];
 284
 285                         $data['orderedItems'] = $list;
 286                 }
 287
 288                 return $data;
 289         }
 290
 291         /**
 292          * Return the service array containing information the used software and it's url
 293          *
 294          * @return array with service data
 295          */
 296         private static function getService()
 297         {
 298                 return ['type' => 'Service',
 299                         'name' =>  FRIENDICA_PLATFORM . " '" . FRIENDICA_CODENAME . "' " . FRIENDICA_VERSION . '-' . DB_UPDATE_VERSION,
 300                         'url' => DI::baseUrl()->get()];
 301         }
 302
 303         /**
 304          * Return the ActivityPub profile of the given user
 305          *
 306          * @param int $uid User ID
 307          * @return array with profile data
 308          * @throws HTTPException\NotFoundException
 309          * @throws HTTPException\InternalServerErrorException
 310          */
 311         public static function getProfile(int $uid): array
 312         {
 313                 $owner = User::getOwnerDataById($uid);
 314                 if (!isset($owner['id'])) {
 315                         DI::logger()->error('Unable to find owner data for uid', ['uid' => $uid, 'callstack' => System::callstack(20)]);
 316                         throw new HTTPException\NotFoundException('User not found.');
 317                 }
 318
 319                 $data = ['@context' => ActivityPub::CONTEXT];
 320                 $data['id'] = $owner['url'];
 321
 322                 if (!empty($owner['guid'])) {
 323                         $data['diaspora:guid'] = $owner['guid'];
 324                 }
 325
 326                 $data['type'] = ActivityPub::ACCOUNT_TYPES[$owner['account-type']];
 327
 328                 if ($uid != 0) {
 329                         $data['following'] = DI::baseUrl() . '/following/' . $owner['nick'];
 330                         $data['followers'] = DI::baseUrl() . '/followers/' . $owner['nick'];
 331                         $data['inbox'] = DI::baseUrl() . '/inbox/' . $owner['nick'];
 332                         $data['outbox'] = DI::baseUrl() . '/outbox/' . $owner['nick'];
 333                 } else {
 334                         $data['inbox'] = DI::baseUrl() . '/friendica/inbox';
 335                 }
 336
 337                 $data['preferredUsername'] = $owner['nick'];
 338                 $data['name'] = $owner['name'];
 339
 340                 if (!empty($owner['country-name'] . $owner['region'] . $owner['locality'])) {
 341                         $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $owner['country-name'],
 342                                 'vcard:region' => $owner['region'], 'vcard:locality' => $owner['locality']];
 343                 }
 344
 345                 if (!empty($owner['about'])) {
 346                         $data['summary'] = BBCode::convertForUriId($owner['uri-id'] ?? 0, $owner['about'], BBCode::EXTERNAL);
 347                 }
 348
 349                 if (!empty($owner['xmpp']) || !empty($owner['matrix'])) {
 350                         $data['vcard:hasInstantMessage'] = [];
 351
 352                         if (!empty($owner['xmpp'])) {
 353                                 $data['vcard:hasInstantMessage'][] = 'xmpp:' . $owner['xmpp'];
 354                         }
 355                         if (!empty($owner['matrix'])) {
 356                                 $data['vcard:hasInstantMessage'][] = 'matrix:' . $owner['matrix'];
 357                         }
 358                 }
 359
 360                 $data['url'] = $owner['url'];
 361                 $data['manuallyApprovesFollowers'] = in_array($owner['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 362                 $data['discoverable'] = (bool)$owner['net-publish'];
 363                 $data['publicKey'] = ['id' => $owner['url'] . '#main-key',
 364                         'owner' => $owner['url'],
 365                         'publicKeyPem' => $owner['pubkey']];
 366                 $data['endpoints'] = ['sharedInbox' => DI::baseUrl() . '/inbox'];
 367                 $data['icon'] = ['type' => 'Image', 'url' => User::getAvatarUrl($owner)];
 368
 369                 $resourceid = Photo::ridFromURI($owner['photo']);
 370                 if (!empty($resourceid)) {
 371                         $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 372                         if (!empty($photo['type'])) {
 373                                 $data['icon']['mediaType'] = $photo['type'];
 374                         }
 375                 }
 376
 377                 if (!empty($owner['header'])) {
 378                         $data['image'] = ['type' => 'Image', 'url' => Contact::getHeaderUrlForId($owner['id'], '', $owner['updated'])];
 379
 380                         $resourceid = Photo::ridFromURI($owner['header']);
 381                         if (!empty($resourceid)) {
 382                                 $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 383                                 if (!empty($photo['type'])) {
 384                                         $data['image']['mediaType'] = $photo['type'];
 385                                 }
 386                         }
 387                 }
 388
 389                 $custom_fields = [];
 390
 391                 foreach (DI::profileField()->selectByContactId(0, $uid) as $profile_field) {
 392                         $custom_fields[] = [
 393                                 'type' => 'PropertyValue',
 394                                 'name' => $profile_field->label,
 395                                 'value' => BBCode::convertForUriId($owner['uri-id'], $profile_field->value)
 396                         ];
 397                 };
 398
 399                 if (!empty($custom_fields)) {
 400                         $data['attachment'] = $custom_fields;
 401                 }
 402
 403                 $data['generator'] = self::getService();
 404
 405                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 406                 return $data;
 407         }
 408
 409         /**
 410          * @param string $username
 411          * @return array
 412          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 413          */
 414         public static function getDeletedUser($username)
 415         {
 416                 return [
 417                         '@context' => ActivityPub::CONTEXT,
 418                         'id' => DI::baseUrl() . '/profile/' . $username,
 419                         'type' => 'Tombstone',
 420                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 421                         'updated' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 422                         'deleted' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 423                 ];
 424         }
 425
 426         /**
 427          * Returns an array with permissions of the thread parent of the given item array
 428          *
 429          * @param array $item
 430          *
 431          * @return array with permissions
 432          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 433          * @throws \ImagickException
 434          */
 435         public static function fetchPermissionBlockFromThreadParent($item)
 436         {
 437                 if (empty($item['thr-parent-id'])) {
 438                         return [];
 439                 }
 440
 441                 $parent = Post::selectFirstPost(['author-link'], ['uri-id' => $item['thr-parent-id']]);
 442                 if (empty($parent)) {
 443                         return [];
 444                 }
 445
 446                 $permissions = [
 447                         'to' => [$parent['author-link']],
 448                         'cc' => [],
 449                         'bto' => [],
 450                         'bcc' => [],
 451                 ];
 452
 453                 $parent_profile = APContact::getByURL($parent['author-link']);
 454
 455                 $item_profile = APContact::getByURL($item['author-link']);
 456                 $exclude[] = $item['author-link'];
 457
 458                 if ($item['gravity'] == GRAVITY_PARENT) {
 459                         $exclude[] = $item['owner-link'];
 460                 }
 461
 462                 $type = [Tag::TO => 'to', Tag::CC => 'cc', Tag::BTO => 'bto', Tag::BCC => 'bcc'];
 463                 foreach (Tag::getByURIId($item['thr-parent-id'], [Tag::TO, Tag::CC, Tag::BTO, Tag::BCC]) as $receiver) {
 464                         if (!empty($parent_profile['followers']) && $receiver['url'] == $parent_profile['followers'] && !empty($item_profile['followers'])) {
 465                                 $permissions[$type[$receiver['type']]][] = $item_profile['followers'];
 466                         } elseif (!in_array($receiver['url'], $exclude)) {
 467                                 $permissions[$type[$receiver['type']]][] = $receiver['url'];
 468                         }
 469                 }
 470
 471                 return $permissions;
 472         }
 473
 474         /**
 475          * Check if the given item id is from ActivityPub
 476          *
 477          * @param integer $item_id
 478          * @return boolean "true" if the post is from ActivityPub
 479          */
 480         private static function isAPPost(int $item_id)
 481         {
 482                 if (empty($item_id)) {
 483                         return false;
 484                 }
 485
 486                 return Post::exists(['id' => $item_id, 'network' => Protocol::ACTIVITYPUB]);
 487         }
 488
 489         /**
 490          * Creates an array of permissions from an item thread
 491          *
 492          * @param array   $item      Item array
 493          * @param boolean $blindcopy addressing via "bcc" or "cc"?
 494          * @param integer $last_id   Last item id for adding receivers
 495          *
 496          * @return array with permission data
 497          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 498          * @throws \ImagickException
 499          */
 500         private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0)
 501         {
 502                 if ($last_id == 0) {
 503                         $last_id = $item['id'];
 504                 }
 505
 506                 $always_bcc = false;
 507                 $is_forum   = false;
 508                 $follower   = '';
 509
 510                 // Check if we should always deliver our stuff via BCC
 511                 if (!empty($item['uid'])) {
 512                         $owner = User::getOwnerDataById($item['uid']);
 513                         if (!empty($owner)) {
 514                                 $always_bcc = $owner['hide-friends'];
 515                                 $is_forum   = ($owner['account-type'] == User::ACCOUNT_TYPE_COMMUNITY) && $owner['manually-approve'];
 516
 517                                 $profile  = APContact::getByURL($owner['url'], false);
 518                                 $follower = $profile['followers'] ?? '';
 519                         }
 520                 }
 521
 522                 if (DI::config()->get('system', 'ap_always_bcc')) {
 523                         $always_bcc = true;
 524                 }
 525
 526                 if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery') || self::isAPPost($last_id)) {
 527                         // Will be activated in a later step
 528                         $networks = Protocol::FEDERATED;
 529                 } else {
 530                         // For now only send to these contacts:
 531                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 532                 }
 533
 534                 $data = ['to' => [], 'cc' => [], 'bcc' => []];
 535
 536                 if ($item['gravity'] == GRAVITY_PARENT) {
 537                         $actor_profile = APContact::getByURL($item['owner-link']);
 538                 } else {
 539                         $actor_profile = APContact::getByURL($item['author-link']);
 540                 }
 541
 542                 $exclusive = false;
 543
 544                 $terms = Tag::getByURIId($item['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
 545
 546                 if ($item['private'] != Item::PRIVATE) {
 547                         // Directly mention the original author upon a quoted reshare.
 548                         // Else just ensure that the original author receives the reshare.
 549                         $announce = self::getAnnounceArray($item);
 550                         if (!empty($announce['comment'])) {
 551                                 $data['to'][] = $announce['actor']['url'];
 552                         } elseif (!empty($announce)) {
 553                                 $data['cc'][] = $announce['actor']['url'];
 554                         }
 555
 556                         $data = array_merge($data, self::fetchPermissionBlockFromThreadParent($item));
 557
 558                         // Check if the item is completely public or unlisted
 559                         if ($item['private'] == Item::PUBLIC) {
 560                                 $data['to'][] = ActivityPub::PUBLIC_COLLECTION;
 561                         } else {
 562                                 $data['cc'][] = ActivityPub::PUBLIC_COLLECTION;
 563                         }
 564
 565                         foreach ($terms as $term) {
 566                                 $profile = APContact::getByURL($term['url'], false);
 567                                 if (!empty($profile)) {
 568                                         if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
 569                                                 $exclusive = true;
 570                                                 if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
 571                                                         $data['cc'][] = $profile['followers'];
 572                                                 }
 573                                         }
 574                                         $data['to'][] = $profile['url'];
 575                                 }
 576                         }
 577                 } else {
 578                         $receiver_list = Item::enumeratePermissions($item, true);
 579
 580                         foreach ($terms as $term) {
 581                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 582                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 583                                         $contact = DBA::selectFirst('contact', ['url', 'network', 'protocol', 'gsid'], ['id' => $cid, 'network' => Protocol::FEDERATED]);
 584                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 585                                                 continue;
 586                                         }
 587
 588                                         $profile = APContact::getByURL($term['url'], false);
 589                                         if (!empty($profile)) {
 590                                                 if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
 591                                                         $exclusive = true;
 592                                                         if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
 593                                                                 $data['cc'][] = $profile['followers'];
 594                                                         }
 595                                                 }
 596                                                 $data['to'][] = $profile['url'];
 597                                         }
 598                                 }
 599                         }
 600
 601                         if ($is_forum && !$exclusive && !empty($follower)) {
 602                                 $data['cc'][] = $follower;
 603                         } elseif (!$exclusive) {
 604                                 foreach ($receiver_list as $receiver) {
 605                                         $contact = DBA::selectFirst('contact', ['url', 'hidden', 'network', 'protocol', 'gsid'], ['id' => $receiver, 'network' => Protocol::FEDERATED]);
 606                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 607                                                 continue;
 608                                         }
 609
 610                                         if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 611                                                 if ($contact['hidden'] || $always_bcc) {
 612                                                         $data['bcc'][] = $profile['url'];
 613                                                 } else {
 614                                                         $data['cc'][] = $profile['url'];
 615                                                 }
 616                                         }
 617                                 }
 618                         }
 619                 }
 620
 621                 if (!empty($item['parent'])) {
 622                         $parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']]);
 623                         while ($parent = Post::fetch($parents)) {
 624                                 if ($parent['gravity'] == GRAVITY_PARENT) {
 625                                         $profile = APContact::getByURL($parent['owner-link'], false);
 626                                         if (!empty($profile)) {
 627                                                 if ($item['gravity'] != GRAVITY_PARENT) {
 628                                                         // Comments to forums are directed to the forum
 629                                                         // But comments to forums aren't directed to the followers collection
 630                                                         // This rule is only valid when the actor isn't the forum.
 631                                                         // The forum needs to transmit their content to their followers.
 632                                                         if (($profile['type'] == 'Group') && ($profile['url'] != ($actor_profile['url'] ?? ''))) {
 633                                                                 $data['to'][] = $profile['url'];
 634                                                         } else {
 635                                                                 $data['cc'][] = $profile['url'];
 636                                                                 if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])) {
 637                                                                         $data['cc'][] = $actor_profile['followers'];
 638                                                                 }
 639                                                         }
 640                                                 } elseif (!$exclusive) {
 641                                                         // Public thread parent post always are directed to the followers.
 642                                                         if ($item['private'] != Item::PRIVATE) {
 643                                                                 $data['cc'][] = $actor_profile['followers'];
 644                                                         }
 645                                                 }
 646                                         }
 647                                 }
 648
 649                                 // Don't include data from future posts
 650                                 if ($parent['id'] >= $last_id) {
 651                                         continue;
 652                                 }
 653
 654                                 $profile = APContact::getByURL($parent['author-link'], false);
 655                                 if (!empty($profile)) {
 656                                         if (($profile['type'] == 'Group') || ($parent['uri'] == $item['thr-parent'])) {
 657                                                 $data['to'][] = $profile['url'];
 658                                         } else {
 659                                                 $data['cc'][] = $profile['url'];
 660                                         }
 661                                 }
 662                         }
 663                         DBA::close($parents);
 664                 }
 665
 666                 $data['to'] = array_unique($data['to']);
 667                 $data['cc'] = array_unique($data['cc']);
 668                 $data['bcc'] = array_unique($data['bcc']);
 669
 670                 if (($key = array_search($item['author-link'], $data['to'])) !== false) {
 671                         unset($data['to'][$key]);
 672                 }
 673
 674                 if (($key = array_search($item['author-link'], $data['cc'])) !== false) {
 675                         unset($data['cc'][$key]);
 676                 }
 677
 678                 if (($key = array_search($item['author-link'], $data['bcc'])) !== false) {
 679                         unset($data['bcc'][$key]);
 680                 }
 681
 682                 foreach ($data['to'] as $to) {
 683                         if (($key = array_search($to, $data['cc'])) !== false) {
 684                                 unset($data['cc'][$key]);
 685                         }
 686
 687                         if (($key = array_search($to, $data['bcc'])) !== false) {
 688                                 unset($data['bcc'][$key]);
 689                         }
 690                 }
 691
 692                 foreach ($data['cc'] as $cc) {
 693                         if (($key = array_search($cc, $data['bcc'])) !== false) {
 694                                 unset($data['bcc'][$key]);
 695                         }
 696                 }
 697
 698                 $receivers = ['to' => array_values($data['to']), 'cc' => array_values($data['cc']), 'bcc' => array_values($data['bcc'])];
 699
 700                 if (!$blindcopy) {
 701                         unset($receivers['bcc']);
 702                 }
 703
 704                 foreach (['to' => Tag::TO, 'cc' => Tag::CC, 'bcc' => Tag::BCC] as $element => $type) {
 705                         if (!empty($receivers[$element])) {
 706                                 foreach ($receivers[$element] as $receiver) {
 707                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
 708                                                 $name = Receiver::PUBLIC_COLLECTION;
 709                                         } else {
 710                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
 711                                         }
 712                                         Tag::store($item['uri-id'], $type, $name, $receiver);
 713                                 }
 714                         }
 715                 }
 716
 717                 return $receivers;
 718         }
 719
 720         /**
 721          * Check if an inbox is archived
 722          *
 723          * @param string $url Inbox url
 724          *
 725          * @return boolean "true" if inbox is archived
 726          */
 727         public static function archivedInbox($url)
 728         {
 729                 return DBA::exists('inbox-status', ['url' => $url, 'archive' => true]);
 730         }
 731
 732         /**
 733          * Check if a given contact should be delivered via AP
 734          *
 735          * @param array $contact
 736          * @param array $networks
 737          * @return bool
 738          * @throws Exception
 739          */
 740         private static function isAPContact(array $contact, array $networks)
 741         {
 742                 if (in_array($contact['network'], $networks) || ($contact['protocol'] == Protocol::ACTIVITYPUB)) {
 743                         return true;
 744                 }
 745
 746                 return GServer::getProtocol($contact['gsid'] ?? 0) == Post\DeliveryData::ACTIVITYPUB;
 747         }
 748
 749         /**
 750          * Fetches a list of inboxes of followers of a given user
 751          *
 752          * @param integer $uid      User ID
 753          * @param boolean $personal fetch personal inboxes
 754          * @param boolean $all_ap   Retrieve all AP enabled inboxes
 755          *
 756          * @return array of follower inboxes
 757          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 758          * @throws \ImagickException
 759          */
 760         public static function fetchTargetInboxesforUser($uid, $personal = false, bool $all_ap = false)
 761         {
 762                 $inboxes = [];
 763
 764                 $isforum = false;
 765
 766                 if (!empty($item['uid'])) {
 767                         $profile = User::getOwnerDataById($item['uid']);
 768                         if (!empty($profile)) {
 769                                 $isforum = $profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY;
 770                         }
 771                 }
 772
 773                 if (DI::config()->get('debug', 'total_ap_delivery') || $all_ap) {
 774                         // Will be activated in a later step
 775                         $networks = Protocol::FEDERATED;
 776                 } else {
 777                         // For now only send to these contacts:
 778                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 779                 }
 780
 781                 $condition = ['uid' => $uid, 'archive' => false, 'pending' => false, 'blocked' => false, 'network' => Protocol::FEDERATED];
 782
 783                 if (!empty($uid)) {
 784                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
 785                 }
 786
 787                 $contacts = DBA::select('contact', ['id', 'url', 'network', 'protocol', 'gsid'], $condition);
 788                 while ($contact = DBA::fetch($contacts)) {
 789                         if (!self::isAPContact($contact, $networks)) {
 790                                 continue;
 791                         }
 792
 793                         if ($isforum && ($contact['network'] == Protocol::DFRN)) {
 794                                 continue;
 795                         }
 796
 797                         if (Network::isUrlBlocked($contact['url'])) {
 798                                 continue;
 799                         }
 800
 801                         $profile = APContact::getByURL($contact['url'], false);
 802                         if (!empty($profile)) {
 803                                 if (empty($profile['sharedinbox']) || $personal || Contact::isLocal($contact['url'])) {
 804                                         $target = $profile['inbox'];
 805                                 } else {
 806                                         $target = $profile['sharedinbox'];
 807                                 }
 808                                 if (!self::archivedInbox($target)) {
 809                                         $inboxes[$target][] = $contact['id'];
 810                                 }
 811                         }
 812                 }
 813                 DBA::close($contacts);
 814
 815                 return $inboxes;
 816         }
 817
 818         /**
 819          * Fetches an array of inboxes for the given item and user
 820          *
 821          * @param array   $item     Item array
 822          * @param integer $uid      User ID
 823          * @param boolean $personal fetch personal inboxes
 824          * @param integer $last_id  Last item id for adding receivers
 825          * @return array with inboxes
 826          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 827          * @throws \ImagickException
 828          */
 829         public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0)
 830         {
 831                 $permissions = self::createPermissionBlockForItem($item, true, $last_id);
 832                 if (empty($permissions)) {
 833                         return [];
 834                 }
 835
 836                 $inboxes = [];
 837
 838                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
 839                         $item_profile = APContact::getByURL($item['author-link'], false);
 840                 } else {
 841                         $item_profile = APContact::getByURL($item['owner-link'], false);
 842                 }
 843
 844                 if (empty($item_profile)) {
 845                         return [];
 846                 }
 847
 848                 $profile_uid = User::getIdForURL($item_profile['url']);
 849
 850                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 851                         if (empty($permissions[$element])) {
 852                                 continue;
 853                         }
 854
 855                         $blindcopy = in_array($element, ['bto', 'bcc']);
 856
 857                         foreach ($permissions[$element] as $receiver) {
 858                                 if (empty($receiver) || Network::isUrlBlocked($receiver)) {
 859                                         continue;
 860                                 }
 861
 862                                 if ($item_profile && ($receiver == $item_profile['followers']) && ($uid == $profile_uid)) {
 863                                         $inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal, self::isAPPost($last_id)));
 864                                 } else {
 865                                         $profile = APContact::getByURL($receiver, false);
 866                                         if (!empty($profile)) {
 867                                                 $contact = Contact::getByURLForUser($receiver, $uid, false, ['id']);
 868
 869                                                 if (empty($profile['sharedinbox']) || $personal || $blindcopy || Contact::isLocal($receiver)) {
 870                                                         $target = $profile['inbox'];
 871                                                 } else {
 872                                                         $target = $profile['sharedinbox'];
 873                                                 }
 874                                                 if (!self::archivedInbox($target)) {
 875                                                         $inboxes[$target][] = $contact['id'] ?? 0;
 876                                                 }
 877                                         }
 878                                 }
 879                         }
 880                 }
 881
 882                 return $inboxes;
 883         }
 884
 885         /**
 886          * Creates an array in the structure of the item table for a given mail id
 887          *
 888          * @param integer $mail_id
 889          *
 890          * @return array
 891          * @throws \Exception
 892          */
 893         public static function ItemArrayFromMail($mail_id, $use_title = false)
 894         {
 895                 $mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
 896                 if (!DBA::isResult($mail)) {
 897                         return [];
 898                 }
 899
 900                 $reply = DBA::selectFirst('mail', ['uri', 'uri-id', 'from-url'], ['parent-uri' => $mail['parent-uri'], 'reply' => false]);
 901                 if (!DBA::isResult($reply)) {
 902                         $reply = $mail;
 903                 }
 904
 905                 // Making the post more compatible for Mastodon by:
 906                 // - Making it a note and not an article (no title)
 907                 // - Moving the title into the "summary" field that is used as a "content warning"
 908
 909                 if (!$use_title) {
 910                         $mail['body']         = '[abstract]' . $mail['title'] . "[/abstract]\n" . $mail['body'];
 911                         $mail['title']        = '';
 912                 }
 913
 914                 $mail['author-link']      = $mail['owner-link'] = $mail['from-url'];
 915                 $mail['owner-id']         = $mail['author-id'];
 916                 $mail['allow_cid']        = '<'.$mail['contact-id'].'>';
 917                 $mail['allow_gid']        = '';
 918                 $mail['deny_cid']         = '';
 919                 $mail['deny_gid']         = '';
 920                 $mail['private']          = Item::PRIVATE;
 921                 $mail['deleted']          = false;
 922                 $mail['edited']           = $mail['created'];
 923                 $mail['plink']            = DI::baseUrl() . '/message/' . $mail['id'];
 924                 $mail['parent-uri']       = $reply['uri'];
 925                 $mail['parent-uri-id']    = $reply['uri-id'];
 926                 $mail['parent-author-id'] = Contact::getIdForURL($reply['from-url'], 0, false);
 927                 $mail['gravity']          = ($mail['reply'] ? GRAVITY_COMMENT: GRAVITY_PARENT);
 928                 $mail['event-type']       = '';
 929                 $mail['language']         = '';
 930                 $mail['parent']           = 0;
 931
 932                 return $mail;
 933         }
 934
 935         /**
 936          * Creates an activity array for a given mail id
 937          *
 938          * @param integer $mail_id
 939          * @param boolean $object_mode Is the activity item is used inside another object?
 940          *
 941          * @return array of activity
 942          * @throws \Exception
 943          */
 944         public static function createActivityFromMail($mail_id, $object_mode = false)
 945         {
 946                 $mail = self::ItemArrayFromMail($mail_id);
 947                 if (empty($mail)) {
 948                         return [];
 949                 }
 950                 $object = self::createNote($mail);
 951
 952                 if (!$object_mode) {
 953                         $data = ['@context' => ActivityPub::CONTEXT];
 954                 } else {
 955                         $data = [];
 956                 }
 957
 958                 $data['id'] = $mail['uri'] . '/Create';
 959                 $data['type'] = 'Create';
 960                 $data['actor'] = $mail['author-link'];
 961                 $data['published'] = DateTimeFormat::utc($mail['created'] . '+00:00', DateTimeFormat::ATOM);
 962                 $data['instrument'] = self::getService();
 963                 $data = array_merge($data, self::createPermissionBlockForItem($mail, true));
 964
 965                 if (empty($data['to']) && !empty($data['cc'])) {
 966                         $data['to'] = $data['cc'];
 967                 }
 968
 969                 if (empty($data['to']) && !empty($data['bcc'])) {
 970                         $data['to'] = $data['bcc'];
 971                 }
 972
 973                 unset($data['cc']);
 974                 unset($data['bcc']);
 975
 976                 $object['to'] = $data['to'];
 977                 $object['tag'] = [['type' => 'Mention', 'href' => $object['to'][0], 'name' => '']];
 978
 979                 unset($object['cc']);
 980                 unset($object['bcc']);
 981
 982                 $data['directMessage'] = true;
 983
 984                 $data['object'] = $object;
 985
 986                 $owner = User::getOwnerDataById($mail['uid']);
 987
 988                 if (!$object_mode && !empty($owner)) {
 989                         return LDSignature::sign($data, $owner);
 990                 } else {
 991                         return $data;
 992                 }
 993         }
 994
 995         /**
 996          * Returns the activity type of a given item
 997          *
 998          * @param array $item
 999          *
1000          * @return string with activity type
1001          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1002          * @throws \ImagickException
1003          */
1004         private static function getTypeOfItem($item)
1005         {
1006                 $reshared = false;
1007
1008                 // Only check for a reshare, if it is a real reshare and no quoted reshare
1009                 if (strpos($item['body'], "[share") === 0) {
1010                         $announce = self::getAnnounceArray($item);
1011                         $reshared = !empty($announce);
1012                 }
1013
1014                 if ($reshared) {
1015                         $type = 'Announce';
1016                 } elseif ($item['verb'] == Activity::POST) {
1017                         if ($item['created'] == $item['edited']) {
1018                                 $type = 'Create';
1019                         } else {
1020                                 $type = 'Update';
1021                         }
1022                 } elseif ($item['verb'] == Activity::LIKE) {
1023                         $type = 'Like';
1024                 } elseif ($item['verb'] == Activity::DISLIKE) {
1025                         $type = 'Dislike';
1026                 } elseif ($item['verb'] == Activity::ATTEND) {
1027                         $type = 'Accept';
1028                 } elseif ($item['verb'] == Activity::ATTENDNO) {
1029                         $type = 'Reject';
1030                 } elseif ($item['verb'] == Activity::ATTENDMAYBE) {
1031                         $type = 'TentativeAccept';
1032                 } elseif ($item['verb'] == Activity::FOLLOW) {
1033                         $type = 'Follow';
1034                 } elseif ($item['verb'] == Activity::TAG) {
1035                         $type = 'Add';
1036                 } elseif ($item['verb'] == Activity::ANNOUNCE) {
1037                         $type = 'Announce';
1038                 } else {
1039                         $type = '';
1040                 }
1041
1042                 return $type;
1043         }
1044
1045         /**
1046          * Creates the activity or fetches it from the cache
1047          *
1048          * @param integer $item_id
1049          * @param boolean $force Force new cache entry
1050          *
1051          * @return array with the activity
1052          * @throws \Exception
1053          */
1054         public static function createCachedActivityFromItem($item_id, $force = false)
1055         {
1056                 $cachekey = 'APDelivery:createActivity:' . $item_id;
1057
1058                 if (!$force) {
1059                         $data = DI::cache()->get($cachekey);
1060                         if (!is_null($data)) {
1061                                 return $data;
1062                         }
1063                 }
1064
1065                 $data = self::createActivityFromItem($item_id);
1066
1067                 DI::cache()->set($cachekey, $data, Duration::QUARTER_HOUR);
1068                 return $data;
1069         }
1070
1071         /**
1072          * Creates an activity array for a given item id
1073          *
1074          * @param integer $item_id
1075          * @param boolean $object_mode Is the activity item is used inside another object?
1076          *
1077          * @return false|array
1078          * @throws \Exception
1079          */
1080         public static function createActivityFromItem(int $item_id, bool $object_mode = false)
1081         {
1082                 Logger::info('Fetching activity', ['item' => $item_id]);
1083                 $item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
1084                 if (!DBA::isResult($item)) {
1085                         return false;
1086                 }
1087
1088                 if (empty($item['uri-id'])) {
1089                         Logger::warning('Item without uri-id', ['item' => $item]);
1090                         return false;
1091                 }
1092
1093                 if (!$item['deleted']) {
1094                         $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
1095                         $conversation = DBA::selectFirst('conversation', ['source'], $condition);
1096                         if (!$item['origin'] && DBA::isResult($conversation)) {
1097                                 $data = json_decode($conversation['source'], true);
1098                                 if (!empty($data['type'])) {
1099                                         if (in_array($data['type'], ['Create', 'Update'])) {
1100                                                 if ($object_mode) {
1101                                                         unset($data['@context']);
1102                                                         unset($data['signature']);
1103                                                 }
1104                                                 Logger::info('Return stored conversation', ['item' => $item_id]);
1105                                                 return $data;
1106                                         } elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
1107                                                 if (!empty($data['@context'])) {
1108                                                         $context = $data['@context'];
1109                                                         unset($data['@context']);
1110                                                 }
1111                                                 unset($data['actor']);
1112                                                 $object = $data;
1113                                         }
1114                                 }
1115                         }
1116                 }
1117
1118                 $type = self::getTypeOfItem($item);
1119
1120                 if (!$object_mode) {
1121                         $data = ['@context' => $context ?? ActivityPub::CONTEXT];
1122
1123                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
1124                                 $type = 'Undo';
1125                         } elseif ($item['deleted']) {
1126                                 $type = 'Delete';
1127                         }
1128                 } else {
1129                         $data = [];
1130                 }
1131
1132                 if ($type == 'Delete') {
1133                         $data['id'] = Item::newURI($item['uid'], $item['guid']) . '/' . $type;;
1134                 } elseif (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
1135                         $data['id'] = $item['uri'];
1136                 } else {
1137                         $data['id'] = $item['uri'] . '/' . $type;
1138                 }
1139
1140                 $data['type'] = $type;
1141
1142                 if (($type != 'Announce') || ($item['gravity'] != GRAVITY_PARENT)) {
1143                         $data['actor'] = $item['author-link'];
1144                 } else {
1145                         $data['actor'] = $item['owner-link'];
1146                 }
1147
1148                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1149
1150                 $data['instrument'] = self::getService();
1151
1152                 $data = array_merge($data, self::createPermissionBlockForItem($item, false));
1153
1154                 if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
1155                         $data['object'] = $object ?? self::createNote($item);
1156                 } elseif ($data['type'] == 'Add') {
1157                         $data = self::createAddTag($item, $data);
1158                 } elseif ($data['type'] == 'Announce') {
1159                         if ($item['verb'] == ACTIVITY::ANNOUNCE) {
1160                                 $data['object'] = $item['thr-parent'];
1161                         } else {
1162                                 $data = self::createAnnounce($item, $data);
1163                         }
1164                 } elseif ($data['type'] == 'Follow') {
1165                         $data['object'] = $item['parent-uri'];
1166                 } elseif ($data['type'] == 'Undo') {
1167                         $data['object'] = self::createActivityFromItem($item_id, true);
1168                 } else {
1169                         $data['diaspora:guid'] = $item['guid'];
1170                         if (!empty($item['signed_text'])) {
1171                                 $data['diaspora:like'] = $item['signed_text'];
1172                         }
1173                         $data['object'] = $item['thr-parent'];
1174                 }
1175
1176                 if (!empty($item['contact-uid'])) {
1177                         $uid = $item['contact-uid'];
1178                 } else {
1179                         $uid = $item['uid'];
1180                 }
1181
1182                 $owner = User::getOwnerDataById($uid);
1183
1184                 Logger::info('Fetched activity', ['item' => $item_id, 'uid' => $uid]);
1185
1186                 // We don't sign if we aren't the actor. This is important for relaying content especially for forums
1187                 if (!$object_mode && !empty($owner) && ($data['actor'] == $owner['url'])) {
1188                         return LDSignature::sign($data, $owner);
1189                 } else {
1190                         return $data;
1191                 }
1192
1193                 /// @todo Create "conversation" entry
1194         }
1195
1196         /**
1197          * Creates a location entry for a given item array
1198          *
1199          * @param array $item
1200          *
1201          * @return array with location array
1202          */
1203         private static function createLocation($item)
1204         {
1205                 $location = ['type' => 'Place'];
1206
1207                 if (!empty($item['location'])) {
1208                         $location['name'] = $item['location'];
1209                 }
1210
1211                 $coord = [];
1212
1213                 if (empty($item['coord'])) {
1214                         $coord = Map::getCoordinates($item['location']);
1215                 } else {
1216                         $coords = explode(' ', $item['coord']);
1217                         if (count($coords) == 2) {
1218                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
1219                         }
1220                 }
1221
1222                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
1223                         $location['latitude'] = $coord['lat'];
1224                         $location['longitude'] = $coord['lon'];
1225                 }
1226
1227                 return $location;
1228         }
1229
1230         /**
1231          * Returns a tag array for a given item array
1232          *
1233          * @param array $item
1234          *
1235          * @return array of tags
1236          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1237          */
1238         private static function createTagList($item)
1239         {
1240                 $tags = [];
1241
1242                 $terms = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG, Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1243                 foreach ($terms as $term) {
1244                         if ($term['type'] == Tag::HASHTAG) {
1245                                 $url = DI::baseUrl() . '/search?tag=' . urlencode($term['name']);
1246                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['name']];
1247                         } else {
1248                                 $contact = Contact::getByURL($term['url'], false, ['addr']);
1249                                 if (empty($contact)) {
1250                                         continue;
1251                                 }
1252                                 if (!empty($contact['addr'])) {
1253                                         $mention = '@' . $contact['addr'];
1254                                 } else {
1255                                         $mention = '@' . $term['url'];
1256                                 }
1257
1258                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
1259                         }
1260                 }
1261
1262                 $announce = self::getAnnounceArray($item);
1263                 // Mention the original author upon commented reshares
1264                 if (!empty($announce['comment'])) {
1265                         $tags[] = ['type' => 'Mention', 'href' => $announce['actor']['url'], 'name' => '@' . $announce['actor']['addr']];
1266                 }
1267
1268                 return $tags;
1269         }
1270
1271         /**
1272          * Adds attachment data to the JSON document
1273          *
1274          * @param array  $item Data of the item that is to be posted
1275          * @param string $type Object type
1276          *
1277          * @return array with attachment data
1278          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1279          */
1280         private static function createAttachmentList($item, $type)
1281         {
1282                 $attachments = [];
1283
1284                 $uriids = [$item['uri-id']];
1285                 $shared = BBCode::fetchShareAttributes($item['body']);
1286                 if (!empty($shared['guid'])) {
1287                         $shared_item = Post::selectFirst(['uri-id'], ['guid' => $shared['guid']]);
1288                         if (!empty($shared_item['uri-id'])) {
1289                                 $uriids[] = $shared_item['uri-id'];
1290                         }
1291                 }
1292
1293                 $urls = [];
1294                 foreach ($uriids as $uriid) {
1295                         foreach (Post\Media::getByURIId($uriid, [Post\Media::AUDIO, Post\Media::IMAGE, Post\Media::VIDEO, Post\Media::DOCUMENT, Post\Media::TORRENT]) as $attachment) {
1296                                 if (in_array($attachment['url'], $urls)) {
1297                                         continue;
1298                                 }
1299                                 $urls[] = $attachment['url'];
1300
1301                                 $attach = ['type' => 'Document',
1302                                         'mediaType' => $attachment['mimetype'],
1303                                         'url' => $attachment['url'],
1304                                         'name' => $attachment['description']];
1305
1306                                 if (!empty($attachment['height'])) {
1307                                         $attach['height'] = $attachment['height'];
1308                                 }
1309
1310                                 if (!empty($attachment['width'])) {
1311                                         $attach['width'] = $attachment['width'];
1312                                 }
1313
1314                                 if (!empty($attachment['preview'])) {
1315                                         $attach['image'] = $attachment['preview'];
1316                                 }
1317
1318                                 $attachments[] = $attach;
1319                         }
1320                 }
1321
1322                 return $attachments;
1323         }
1324
1325         /**
1326          * Callback function to replace a Friendica style mention in a mention for a summary
1327          *
1328          * @param array $match Matching values for the callback
1329          * @return string Replaced mention
1330          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1331          */
1332         private static function mentionAddrCallback($match)
1333         {
1334                 if (empty($match[1])) {
1335                         return '';
1336                 }
1337
1338                 $data = Contact::getByURL($match[1], false, ['addr']);
1339                 if (empty($data['addr'])) {
1340                         return $match[0];
1341                 }
1342
1343                 return '@' . $data['addr'];
1344         }
1345
1346         /**
1347          * Remove image elements since they are added as attachment
1348          *
1349          * @param string $body
1350          *
1351          * @return string with removed images
1352          */
1353         private static function removePictures($body)
1354         {
1355                 // Simplify image codes
1356                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
1357                 $body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
1358
1359                 // Now remove local links
1360                 $body = preg_replace_callback(
1361                         '/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi',
1362                         function ($match) {
1363                                 // We remove the link when it is a link to a local photo page
1364                                 if (Photo::isLocalPage($match[1])) {
1365                                         return '';
1366                                 }
1367                                 // otherwise we just return the link
1368                                 return '[url]' . $match[1] . '[/url]';
1369                         },
1370                         $body
1371                 );
1372
1373                 // Remove all pictures
1374                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '', $body);
1375
1376                 return $body;
1377         }
1378
1379         /**
1380          * Fetches the "context" value for a givem item array from the "conversation" table
1381          *
1382          * @param array $item
1383          *
1384          * @return string with context url
1385          * @throws \Exception
1386          */
1387         private static function fetchContextURLForItem($item)
1388         {
1389                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
1390                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
1391                         $context_uri = $conversation['conversation-href'];
1392                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
1393                         $context_uri = $conversation['conversation-uri'];
1394                 } else {
1395                         $context_uri = $item['parent-uri'] . '#context';
1396                 }
1397                 return $context_uri;
1398         }
1399
1400         /**
1401          * Returns if the post contains sensitive content ("nsfw")
1402          *
1403          * @param integer $uri_id
1404          *
1405          * @return boolean
1406          * @throws \Exception
1407          */
1408         private static function isSensitive($uri_id)
1409         {
1410                 return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw']);
1411         }
1412
1413         /**
1414          * Creates event data
1415          *
1416          * @param array $item
1417          *
1418          * @return array with the event data
1419          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1420          */
1421         private static function createEvent($item)
1422         {
1423                 $event = [];
1424                 $event['name'] = $item['event-summary'];
1425                 $event['content'] = BBCode::convertForUriId($item['uri-id'], $item['event-desc'], BBCode::ACTIVITYPUB);
1426                 $event['startTime'] = DateTimeFormat::utc($item['event-start'], 'c');
1427
1428                 if (!$item['event-nofinish']) {
1429                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'], 'c');
1430                 }
1431
1432                 if (!empty($item['event-location'])) {
1433                         $item['location'] = $item['event-location'];
1434                         $event['location'] = self::createLocation($item);
1435                 }
1436
1437                 // 2021.12: Backward compatibility value, all the events now "adjust" to the viewer timezone
1438                 $event['dfrn:adjust'] = true;
1439
1440                 return $event;
1441         }
1442
1443         /**
1444          * Creates a note/article object array
1445          *
1446          * @param array $item
1447          *
1448          * @return array with the object data
1449          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1450          * @throws \ImagickException
1451          */
1452         public static function createNote($item)
1453         {
1454                 if (empty($item)) {
1455                         return [];
1456                 }
1457
1458                 if ($item['event-type'] == 'event') {
1459                         $type = 'Event';
1460                 } elseif (!empty($item['title'])) {
1461                         $type = 'Article';
1462                 } else {
1463                         $type = 'Note';
1464                 }
1465
1466                 if ($item['deleted']) {
1467                         $type = 'Tombstone';
1468                 }
1469
1470                 $data = [];
1471                 $data['id'] = $item['uri'];
1472                 $data['type'] = $type;
1473
1474                 if ($item['deleted']) {
1475                         return $data;
1476                 }
1477
1478                 $data['summary'] = BBCode::toPlaintext(BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB));
1479
1480                 if ($item['uri'] != $item['thr-parent']) {
1481                         $data['inReplyTo'] = $item['thr-parent'];
1482                 } else {
1483                         $data['inReplyTo'] = null;
1484                 }
1485
1486                 $data['diaspora:guid'] = $item['guid'];
1487                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1488
1489                 if ($item['created'] != $item['edited']) {
1490                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1491                 }
1492
1493                 $data['url'] = $item['plink'];
1494                 $data['attributedTo'] = $item['author-link'];
1495                 $data['sensitive'] = self::isSensitive($item['uri-id']);
1496                 $data['context'] = self::fetchContextURLForItem($item);
1497
1498                 if (!empty($item['title'])) {
1499                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1500                 }
1501
1502                 $permission_block = self::createPermissionBlockForItem($item, false);
1503
1504                 $body = $item['body'];
1505
1506                 if ($type == 'Note') {
1507                         $body = $item['raw-body'] ?? self::removePictures($body);
1508                 }
1509
1510                 /**
1511                  * @todo Improve the automated summary
1512                  * This part is currently deactivated. The automated summary seems to be more
1513                  * confusing than helping. But possibly we will find a better way.
1514                  * So the code is left here for now as a reminder
1515                  *
1516                  * } elseif (($type == 'Article') && empty($data['summary'])) {
1517                  *              $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1518                  *              $summary = preg_replace_callback($regexp, ['self', 'mentionAddrCallback'], $body);
1519                  *              $data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($summary), 1000));
1520                  * }
1521                  */
1522
1523                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1524                         $body = self::prependMentions($body, $item['uri-id'], $item['author-link']);
1525                 }
1526
1527                 if ($type == 'Event') {
1528                         $data = array_merge($data, self::createEvent($item));
1529                 } else {
1530                         $body = BBCode::setMentionsToNicknames($body);
1531
1532                         $data['content'] = BBCode::convertForUriId($item['uri-id'], $body, BBCode::ACTIVITYPUB);
1533                 }
1534
1535                 // The regular "content" field does contain a minimized HTML. This is done since systems like
1536                 // Mastodon has got problems with - for example - embedded pictures.
1537                 // The contentMap does contain the unmodified HTML.
1538                 $language = self::getLanguage($item);
1539                 if (!empty($language)) {
1540                         $richbody = BBCode::setMentionsToNicknames($item['body'] ?? '');
1541                         $richbody = BBCode::removeAttachment($richbody);
1542
1543                         $data['contentMap'][$language] = BBCode::convertForUriId($item['uri-id'], $richbody, BBCode::EXTERNAL);
1544                 }
1545
1546                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1547
1548                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1549                         $data['diaspora:comment'] = $item['signed_text'];
1550                 }
1551
1552                 $data['attachment'] = self::createAttachmentList($item, $type);
1553                 $data['tag'] = self::createTagList($item);
1554
1555                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1556                         $data['location'] = self::createLocation($item);
1557                 }
1558
1559                 if (!empty($item['app'])) {
1560                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1561                 }
1562
1563                 $data = array_merge($data, $permission_block);
1564
1565                 return $data;
1566         }
1567
1568         /**
1569          * Fetches the language from the post, the user or the system.
1570          *
1571          * @param array $item
1572          *
1573          * @return string language string
1574          */
1575         private static function getLanguage(array $item)
1576         {
1577                 // Try to fetch the language from the post itself
1578                 if (!empty($item['language'])) {
1579                         $languages = array_keys(json_decode($item['language'], true));
1580                         if (!empty($languages[0])) {
1581                                 return $languages[0];
1582                         }
1583                 }
1584
1585                 // Otherwise use the user's language
1586                 if (!empty($item['uid'])) {
1587                         $user = DBA::selectFirst('user', ['language'], ['uid' => $item['uid']]);
1588                         if (!empty($user['language'])) {
1589                                 return $user['language'];
1590                         }
1591                 }
1592
1593                 // And finally just use the system language
1594                 return DI::config()->get('system', 'language');
1595         }
1596
1597         /**
1598          * Creates an an "add tag" entry
1599          *
1600          * @param array $item
1601          * @param array $data activity data
1602          *
1603          * @return array with activity data for adding tags
1604          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1605          * @throws \ImagickException
1606          */
1607         private static function createAddTag($item, $data)
1608         {
1609                 $object = XML::parseString($item['object']);
1610                 $target = XML::parseString($item["target"]);
1611
1612                 $data['diaspora:guid'] = $item['guid'];
1613                 $data['actor'] = $item['author-link'];
1614                 $data['target'] = (string)$target->id;
1615                 $data['summary'] = BBCode::toPlaintext($item['body']);
1616                 $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
1617
1618                 return $data;
1619         }
1620
1621         /**
1622          * Creates an announce object entry
1623          *
1624          * @param array $item
1625          * @param array $data activity data
1626          *
1627          * @return array with activity data
1628          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1629          * @throws \ImagickException
1630          */
1631         private static function createAnnounce($item, $data)
1632         {
1633                 $orig_body = $item['body'];
1634                 $announce = self::getAnnounceArray($item);
1635                 if (empty($announce)) {
1636                         $data['type'] = 'Create';
1637                         $data['object'] = self::createNote($item);
1638                         return $data;
1639                 }
1640
1641                 if (empty($announce['comment'])) {
1642                         // Pure announce, without a quote
1643                         $data['type'] = 'Announce';
1644                         $data['object'] = $announce['object']['uri'];
1645                         return $data;
1646                 }
1647
1648                 // Quote
1649                 $data['type'] = 'Create';
1650                 $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
1651                 $data['object'] = self::createNote($item);
1652
1653                 /// @todo Finally descide how to implement this in AP. This is a possible way:
1654                 $data['object']['attachment'][] = self::createNote($announce['object']);
1655
1656                 $data['object']['source']['content'] = $orig_body;
1657                 return $data;
1658         }
1659
1660         /**
1661          * Return announce related data if the item is an annunce
1662          *
1663          * @param array $item
1664          *
1665          * @return array
1666          */
1667         public static function getAnnounceArray($item)
1668         {
1669                 $reshared = Item::getShareArray($item);
1670                 if (empty($reshared['guid'])) {
1671                         return [];
1672                 }
1673
1674                 $reshared_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['guid' => $reshared['guid']]);
1675                 if (!DBA::isResult($reshared_item)) {
1676                         return [];
1677                 }
1678
1679                 if (!in_array($reshared_item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
1680                         return [];
1681                 }
1682
1683                 $profile = APContact::getByURL($reshared_item['author-link'], false);
1684                 if (empty($profile)) {
1685                         return [];
1686                 }
1687
1688                 return ['object' => $reshared_item, 'actor' => $profile, 'comment' => $reshared['comment']];
1689         }
1690
1691         /**
1692          * Checks if the provided item array is an announce
1693          *
1694          * @param array $item
1695          *
1696          * @return boolean
1697          */
1698         public static function isAnnounce($item)
1699         {
1700                 if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
1701                         return true;
1702                 }
1703
1704                 $announce = self::getAnnounceArray($item);
1705                 if (empty($announce)) {
1706                         return false;
1707                 }
1708
1709                 return empty($announce['comment']);
1710         }
1711
1712         /**
1713          * Creates an activity id for a given contact id
1714          *
1715          * @param integer $cid Contact ID of target
1716          *
1717          * @return bool|string activity id
1718          */
1719         public static function activityIDFromContact($cid)
1720         {
1721                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1722                 if (!DBA::isResult($contact)) {
1723                         return false;
1724                 }
1725
1726                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1727                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1728                 return DI::baseUrl() . '/activity/' . $uuid;
1729         }
1730
1731         /**
1732          * Transmits a contact suggestion to a given inbox
1733          *
1734          * @param integer $uid           User ID
1735          * @param string  $inbox         Target inbox
1736          * @param integer $suggestion_id Suggestion ID
1737          *
1738          * @return boolean was the transmission successful?
1739          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1740          */
1741         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1742         {
1743                 $owner = User::getOwnerDataById($uid);
1744
1745                 $suggestion = DI::fsuggest()->selectOneById($suggestion_id);
1746
1747                 $data = ['@context' => ActivityPub::CONTEXT,
1748                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1749                         'type' => 'Announce',
1750                         'actor' => $owner['url'],
1751                         'object' => $suggestion->url,
1752                         'content' => $suggestion->note,
1753                         'instrument' => self::getService(),
1754                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1755                         'cc' => []];
1756
1757                 $signed = LDSignature::sign($data, $owner);
1758
1759                 Logger::info('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1760                 return HTTPSignature::transmit($signed, $inbox, $uid);
1761         }
1762
1763         /**
1764          * Transmits a profile relocation to a given inbox
1765          *
1766          * @param integer $uid   User ID
1767          * @param string  $inbox Target inbox
1768          *
1769          * @return boolean was the transmission successful?
1770          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1771          */
1772         public static function sendProfileRelocation($uid, $inbox)
1773         {
1774                 $owner = User::getOwnerDataById($uid);
1775
1776                 $data = ['@context' => ActivityPub::CONTEXT,
1777                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1778                         'type' => 'dfrn:relocate',
1779                         'actor' => $owner['url'],
1780                         'object' => $owner['url'],
1781                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1782                         'instrument' => self::getService(),
1783                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1784                         'cc' => []];
1785
1786                 $signed = LDSignature::sign($data, $owner);
1787
1788                 Logger::info('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1789                 return HTTPSignature::transmit($signed, $inbox, $uid);
1790         }
1791
1792         /**
1793          * Transmits a profile deletion to a given inbox
1794          *
1795          * @param integer $uid   User ID
1796          * @param string  $inbox Target inbox
1797          *
1798          * @return boolean was the transmission successful?
1799          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1800          */
1801         public static function sendProfileDeletion($uid, $inbox)
1802         {
1803                 $owner = User::getOwnerDataById($uid);
1804
1805                 if (empty($owner)) {
1806                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1807                         return false;
1808                 }
1809
1810                 if (empty($owner['uprvkey'])) {
1811                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1812                         return false;
1813                 }
1814
1815                 $data = ['@context' => ActivityPub::CONTEXT,
1816                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1817                         'type' => 'Delete',
1818                         'actor' => $owner['url'],
1819                         'object' => $owner['url'],
1820                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1821                         'instrument' => self::getService(),
1822                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1823                         'cc' => []];
1824
1825                 $signed = LDSignature::sign($data, $owner);
1826
1827                 Logger::info('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1828                 return HTTPSignature::transmit($signed, $inbox, $uid);
1829         }
1830
1831         /**
1832          * Transmits a profile change to a given inbox
1833          *
1834          * @param integer $uid   User ID
1835          * @param string  $inbox Target inbox
1836          *
1837          * @return boolean was the transmission successful?
1838          * @throws HTTPException\InternalServerErrorException
1839          * @throws HTTPException\NotFoundException
1840          * @throws \ImagickException
1841          */
1842         public static function sendProfileUpdate(int $uid, string $inbox): bool
1843         {
1844                 $owner = User::getOwnerDataById($uid);
1845                 $profile = APContact::getByURL($owner['url']);
1846
1847                 $data = ['@context' => ActivityPub::CONTEXT,
1848                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1849                         'type' => 'Update',
1850                         'actor' => $owner['url'],
1851                         'object' => self::getProfile($uid),
1852                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1853                         'instrument' => self::getService(),
1854                         'to' => [$profile['followers']],
1855                         'cc' => []];
1856
1857                 $signed = LDSignature::sign($data, $owner);
1858
1859                 Logger::info('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1860                 return HTTPSignature::transmit($signed, $inbox, $uid);
1861         }
1862
1863         /**
1864          * Transmits a given activity to a target
1865          *
1866          * @param string  $activity Type name
1867          * @param string  $target   Target profile
1868          * @param integer $uid      User ID
1869          * @return bool
1870          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1871          * @throws \ImagickException
1872          * @throws \Exception
1873          */
1874         public static function sendActivity($activity, $target, $uid, $id = '')
1875         {
1876                 $profile = APContact::getByURL($target);
1877                 if (empty($profile['inbox'])) {
1878                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1879                         return;
1880                 }
1881
1882                 $owner = User::getOwnerDataById($uid);
1883
1884                 if (empty($id)) {
1885                         $id = DI::baseUrl() . '/activity/' . System::createGUID();
1886                 }
1887
1888                 $data = ['@context' => ActivityPub::CONTEXT,
1889                         'id' => $id,
1890                         'type' => $activity,
1891                         'actor' => $owner['url'],
1892                         'object' => $profile['url'],
1893                         'instrument' => self::getService(),
1894                         'to' => [$profile['url']]];
1895
1896                 Logger::info('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid);
1897
1898                 $signed = LDSignature::sign($data, $owner);
1899                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1900         }
1901
1902         /**
1903          * Transmits a "follow object" activity to a target
1904          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
1905          *
1906          * @param string  $object Object URL
1907          * @param string  $target Target profile
1908          * @param integer $uid    User ID
1909          * @return bool
1910          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1911          * @throws \ImagickException
1912          * @throws \Exception
1913          */
1914         public static function sendFollowObject($object, $target, $uid = 0)
1915         {
1916                 $profile = APContact::getByURL($target);
1917                 if (empty($profile['inbox'])) {
1918                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1919                         return;
1920                 }
1921
1922                 if (empty($uid)) {
1923                         // Fetch the list of administrators
1924                         $admin_mail = explode(',', str_replace(' ', '', DI::config()->get('config', 'admin_email')));
1925
1926                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
1927                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
1928                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
1929                         $uid = $first_user['uid'];
1930                 }
1931
1932                 $condition = ['verb' => Activity::FOLLOW, 'uid' => 0, 'parent-uri' => $object,
1933                         'author-id' => Contact::getPublicIdByUserId($uid)];
1934                 if (Post::exists($condition)) {
1935                         Logger::info('Follow for ' . $object . ' for user ' . $uid . ' does already exist.');
1936                         return false;
1937                 }
1938
1939                 $owner = User::getOwnerDataById($uid);
1940
1941                 $data = ['@context' => ActivityPub::CONTEXT,
1942                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1943                         'type' => 'Follow',
1944                         'actor' => $owner['url'],
1945                         'object' => $object,
1946                         'instrument' => self::getService(),
1947                         'to' => [$profile['url']]];
1948
1949                 Logger::info('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid);
1950
1951                 $signed = LDSignature::sign($data, $owner);
1952                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1953         }
1954
1955         /**
1956          * Transmit a message that the contact request had been accepted
1957          *
1958          * @param string  $target Target profile
1959          * @param         $id
1960          * @param integer $uid    User ID
1961          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1962          * @throws \ImagickException
1963          */
1964         public static function sendContactAccept($target, $id, $uid)
1965         {
1966                 $profile = APContact::getByURL($target);
1967                 if (empty($profile['inbox'])) {
1968                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1969                         return;
1970                 }
1971
1972                 $owner = User::getOwnerDataById($uid);
1973                 $data = ['@context' => ActivityPub::CONTEXT,
1974                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1975                         'type' => 'Accept',
1976                         'actor' => $owner['url'],
1977                         'object' => [
1978                                 'id' => (string)$id,
1979                                 'type' => 'Follow',
1980                                 'actor' => $profile['url'],
1981                                 'object' => $owner['url']
1982                         ],
1983                         'instrument' => self::getService(),
1984                         'to' => [$profile['url']]];
1985
1986                 Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
1987
1988                 $signed = LDSignature::sign($data, $owner);
1989                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
1990         }
1991
1992         /**
1993          * Reject a contact request or terminates the contact relation
1994          *
1995          * @param string  $target Target profile
1996          * @param         $id
1997          * @param integer $uid    User ID
1998          * @return bool Operation success
1999          * @throws HTTPException\InternalServerErrorException
2000          * @throws \ImagickException
2001          */
2002         public static function sendContactReject($target, $id, $uid): bool
2003         {
2004                 $profile = APContact::getByURL($target);
2005                 if (empty($profile['inbox'])) {
2006                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2007                         return false;
2008                 }
2009
2010                 $owner = User::getOwnerDataById($uid);
2011                 $data = ['@context' => ActivityPub::CONTEXT,
2012                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2013                         'type' => 'Reject',
2014                         'actor' => $owner['url'],
2015                         'object' => [
2016                                 'id' => (string)$id,
2017                                 'type' => 'Follow',
2018                                 'actor' => $profile['url'],
2019                                 'object' => $owner['url']
2020                         ],
2021                         'instrument' => self::getService(),
2022                         'to' => [$profile['url']]];
2023
2024                 Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2025
2026                 $signed = LDSignature::sign($data, $owner);
2027                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2028         }
2029
2030         /**
2031          * Transmits a message that we don't want to follow this contact anymore
2032          *
2033          * @param string  $target Target profile
2034          * @param integer $uid    User ID
2035          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2036          * @throws \ImagickException
2037          * @throws \Exception
2038          * @return bool success
2039          */
2040         public static function sendContactUndo($target, $cid, $uid)
2041         {
2042                 $profile = APContact::getByURL($target);
2043                 if (empty($profile['inbox'])) {
2044                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2045                         return false;
2046                 }
2047
2048                 $object_id = self::activityIDFromContact($cid);
2049                 if (empty($object_id)) {
2050                         return false;
2051                 }
2052
2053                 $id = DI::baseUrl() . '/activity/' . System::createGUID();
2054
2055                 $owner = User::getOwnerDataById($uid);
2056                 $data = ['@context' => ActivityPub::CONTEXT,
2057                         'id' => $id,
2058                         'type' => 'Undo',
2059                         'actor' => $owner['url'],
2060                         'object' => ['id' => $object_id, 'type' => 'Follow',
2061                                 'actor' => $owner['url'],
2062                                 'object' => $profile['url']],
2063                         'instrument' => self::getService(),
2064                         'to' => [$profile['url']]];
2065
2066                 Logger::info('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2067
2068                 $signed = LDSignature::sign($data, $owner);
2069                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2070         }
2071
2072         private static function prependMentions($body, int $uriid, string $authorLink)
2073         {
2074                 $mentions = [];
2075
2076                 foreach (Tag::getByURIId($uriid, [Tag::IMPLICIT_MENTION]) as $tag) {
2077                         $profile = Contact::getByURL($tag['url'], false, ['addr', 'contact-type', 'nick']);
2078                         if (!empty($profile['addr'])
2079                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
2080                                 && !strstr($body, $profile['addr'])
2081                                 && !strstr($body, $tag['url'])
2082                                 && $tag['url'] !== $authorLink
2083                         ) {
2084                                 $mentions[] = '@[url=' . $tag['url'] . ']' . $profile['nick'] . '[/url]';
2085                         }
2086                 }
2087
2088                 $mentions[] = $body;
2089
2090                 return implode(' ', $mentions);
2091         }
2092 }