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          * Public posts for the given owner
 293          *
 294          * @param array   $owner Owner array
 295          * @param integer $page  Page number
 296          *
 297          * @return array of posts
 298          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 299          * @throws \ImagickException
 300          */
 301         public static function getFeatured($owner, $page = null)
 302         {
 303                 $condition = ["`uri-id` IN (SELECT `uri-id` FROM `collection-view` WHERE `cid` = ? AND `type` = ?)",
 304                         Contact::getIdForURL($owner['url'], 0, false), Post\Collection::FEATURED];
 305
 306                 $condition = DBA::mergeConditions($condition,
 307                         ['uid'           => $owner['uid'],
 308                         'author-id'      => Contact::getIdForURL($owner['url'], 0, false),
 309                         'private'        => [Item::PUBLIC, Item::UNLISTED],
 310                         'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
 311                         'network'        => Protocol::FEDERATED,
 312                         'parent-network' => Protocol::FEDERATED,
 313                         'origin'         => true,
 314                         'deleted'        => false,
 315                         'visible'        => true]);
 316
 317                 $count = Post::count($condition);
 318
 319                 $data = ['@context' => ActivityPub::CONTEXT];
 320                 $data['id'] = DI::baseUrl() . '/featured/' . $owner['nickname'];
 321                 $data['type'] = 'OrderedCollection';
 322                 $data['totalItems'] = $count;
 323
 324                 if (empty($page)) {
 325                         $data['first'] = DI::baseUrl() . '/featured/' . $owner['nickname'] . '?page=1';
 326                 } else {
 327                         $data['type'] = 'OrderedCollectionPage';
 328                         $list = [];
 329
 330                         $items = Post::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
 331                         while ($item = Post::fetch($items)) {
 332                                 $activity = self::createActivityFromItem($item['id'], true);
 333                                 $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
 334
 335                                 // Only list "Create" activity objects here, no reshares
 336                                 if (!empty($activity['object']) && ($activity['type'] == 'Create')) {
 337                                         $list[] = $activity['object'];
 338                                 }
 339                         }
 340                         DBA::close($items);
 341
 342                         if (!empty($list)) {
 343                                 $data['next'] = DI::baseUrl() . '/featured/' . $owner['nickname'] . '?page=' . ($page + 1);
 344                         }
 345
 346                         $data['partOf'] = DI::baseUrl() . '/featured/' . $owner['nickname'];
 347
 348                         $data['orderedItems'] = $list;
 349                 }
 350
 351                 return $data;
 352         }
 353
 354         /**
 355          * Return the service array containing information the used software and it's url
 356          *
 357          * @return array with service data
 358          */
 359         private static function getService()
 360         {
 361                 return ['type' => 'Service',
 362                         'name' =>  FRIENDICA_PLATFORM . " '" . FRIENDICA_CODENAME . "' " . FRIENDICA_VERSION . '-' . DB_UPDATE_VERSION,
 363                         'url' => DI::baseUrl()->get()];
 364         }
 365
 366         /**
 367          * Return the ActivityPub profile of the given user
 368          *
 369          * @param int $uid User ID
 370          * @return array with profile data
 371          * @throws HTTPException\NotFoundException
 372          * @throws HTTPException\InternalServerErrorException
 373          */
 374         public static function getProfile(int $uid): array
 375         {
 376                 $owner = User::getOwnerDataById($uid);
 377                 if (!isset($owner['id'])) {
 378                         DI::logger()->error('Unable to find owner data for uid', ['uid' => $uid, 'callstack' => System::callstack(20)]);
 379                         throw new HTTPException\NotFoundException('User not found.');
 380                 }
 381
 382                 $data = ['@context' => ActivityPub::CONTEXT];
 383                 $data['id'] = $owner['url'];
 384
 385                 if (!empty($owner['guid'])) {
 386                         $data['diaspora:guid'] = $owner['guid'];
 387                 }
 388
 389                 $data['type'] = ActivityPub::ACCOUNT_TYPES[$owner['account-type']];
 390
 391                 if ($uid != 0) {
 392                         $data['following'] = DI::baseUrl() . '/following/' . $owner['nick'];
 393                         $data['followers'] = DI::baseUrl() . '/followers/' . $owner['nick'];
 394                         $data['inbox']     = DI::baseUrl() . '/inbox/' . $owner['nick'];
 395                         $data['outbox']    = DI::baseUrl() . '/outbox/' . $owner['nick'];
 396                         $data['featured']  = DI::baseUrl() . '/featured/' . $owner['nick'];
 397                 } else {
 398                         $data['inbox'] = DI::baseUrl() . '/friendica/inbox';
 399                 }
 400
 401                 $data['preferredUsername'] = $owner['nick'];
 402                 $data['name'] = $owner['name'];
 403
 404                 if (!empty($owner['country-name'] . $owner['region'] . $owner['locality'])) {
 405                         $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $owner['country-name'],
 406                                 'vcard:region' => $owner['region'], 'vcard:locality' => $owner['locality']];
 407                 }
 408
 409                 if (!empty($owner['about'])) {
 410                         $data['summary'] = BBCode::convertForUriId($owner['uri-id'] ?? 0, $owner['about'], BBCode::EXTERNAL);
 411                 }
 412
 413                 if (!empty($owner['xmpp']) || !empty($owner['matrix'])) {
 414                         $data['vcard:hasInstantMessage'] = [];
 415
 416                         if (!empty($owner['xmpp'])) {
 417                                 $data['vcard:hasInstantMessage'][] = 'xmpp:' . $owner['xmpp'];
 418                         }
 419                         if (!empty($owner['matrix'])) {
 420                                 $data['vcard:hasInstantMessage'][] = 'matrix:' . $owner['matrix'];
 421                         }
 422                 }
 423
 424                 $data['url'] = $owner['url'];
 425                 $data['manuallyApprovesFollowers'] = in_array($owner['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 426                 $data['discoverable'] = (bool)$owner['net-publish'];
 427                 $data['publicKey'] = ['id' => $owner['url'] . '#main-key',
 428                         'owner' => $owner['url'],
 429                         'publicKeyPem' => $owner['pubkey']];
 430                 $data['endpoints'] = ['sharedInbox' => DI::baseUrl() . '/inbox'];
 431                 $data['icon'] = ['type' => 'Image', 'url' => User::getAvatarUrl($owner)];
 432
 433                 $resourceid = Photo::ridFromURI($owner['photo']);
 434                 if (!empty($resourceid)) {
 435                         $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 436                         if (!empty($photo['type'])) {
 437                                 $data['icon']['mediaType'] = $photo['type'];
 438                         }
 439                 }
 440
 441                 if (!empty($owner['header'])) {
 442                         $data['image'] = ['type' => 'Image', 'url' => Contact::getHeaderUrlForId($owner['id'], '', $owner['updated'])];
 443
 444                         $resourceid = Photo::ridFromURI($owner['header']);
 445                         if (!empty($resourceid)) {
 446                                 $photo = Photo::selectFirst(['type'], ["resource-id" => $resourceid]);
 447                                 if (!empty($photo['type'])) {
 448                                         $data['image']['mediaType'] = $photo['type'];
 449                                 }
 450                         }
 451                 }
 452
 453                 $custom_fields = [];
 454
 455                 foreach (DI::profileField()->selectByContactId(0, $uid) as $profile_field) {
 456                         $custom_fields[] = [
 457                                 'type' => 'PropertyValue',
 458                                 'name' => $profile_field->label,
 459                                 'value' => BBCode::convertForUriId($owner['uri-id'], $profile_field->value)
 460                         ];
 461                 };
 462
 463                 if (!empty($custom_fields)) {
 464                         $data['attachment'] = $custom_fields;
 465                 }
 466
 467                 $data['generator'] = self::getService();
 468
 469                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 470                 return $data;
 471         }
 472
 473         /**
 474          * @param string $username
 475          * @return array
 476          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 477          */
 478         public static function getDeletedUser($username)
 479         {
 480                 return [
 481                         '@context' => ActivityPub::CONTEXT,
 482                         'id' => DI::baseUrl() . '/profile/' . $username,
 483                         'type' => 'Tombstone',
 484                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 485                         'updated' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 486                         'deleted' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 487                 ];
 488         }
 489
 490         /**
 491          * Returns an array with permissions of the thread parent of the given item array
 492          *
 493          * @param array $item
 494          * @param bool  $is_forum_thread
 495          *
 496          * @return array with permissions
 497          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 498          * @throws \ImagickException
 499          */
 500         private static function fetchPermissionBlockFromThreadParent(array $item, bool $is_forum_thread)
 501         {
 502                 if (empty($item['thr-parent-id'])) {
 503                         return [];
 504                 }
 505
 506                 $parent = Post::selectFirstPost(['author-link'], ['uri-id' => $item['thr-parent-id']]);
 507                 if (empty($parent)) {
 508                         return [];
 509                 }
 510
 511                 $permissions = [
 512                         'to' => [$parent['author-link']],
 513                         'cc' => [],
 514                         'bto' => [],
 515                         'bcc' => [],
 516                 ];
 517
 518                 $parent_profile = APContact::getByURL($parent['author-link']);
 519
 520                 $item_profile = APContact::getByURL($item['author-link']);
 521                 $exclude[] = $item['author-link'];
 522
 523                 if ($item['gravity'] == GRAVITY_PARENT) {
 524                         $exclude[] = $item['owner-link'];
 525                 }
 526
 527                 $type = [Tag::TO => 'to', Tag::CC => 'cc', Tag::BTO => 'bto', Tag::BCC => 'bcc'];
 528                 foreach (Tag::getByURIId($item['thr-parent-id'], [Tag::TO, Tag::CC, Tag::BTO, Tag::BCC]) as $receiver) {
 529                         if (!empty($parent_profile['followers']) && $receiver['url'] == $parent_profile['followers'] && !empty($item_profile['followers'])) {
 530                                 if (!$is_forum_thread) {
 531                                         $permissions[$type[$receiver['type']]][] = $item_profile['followers'];
 532                                 }
 533                         } elseif (!in_array($receiver['url'], $exclude)) {
 534                                 $permissions[$type[$receiver['type']]][] = $receiver['url'];
 535                         }
 536                 }
 537
 538                 return $permissions;
 539         }
 540
 541         /**
 542          * Check if the given item id is from ActivityPub
 543          *
 544          * @param integer $item_id
 545          * @return boolean "true" if the post is from ActivityPub
 546          */
 547         private static function isAPPost(int $item_id)
 548         {
 549                 if (empty($item_id)) {
 550                         return false;
 551                 }
 552
 553                 return Post::exists(['id' => $item_id, 'network' => Protocol::ACTIVITYPUB]);
 554         }
 555
 556         /**
 557          * Creates an array of permissions from an item thread
 558          *
 559          * @param array   $item      Item array
 560          * @param boolean $blindcopy addressing via "bcc" or "cc"?
 561          * @param integer $last_id   Last item id for adding receivers
 562          *
 563          * @return array with permission data
 564          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 565          * @throws \ImagickException
 566          */
 567         private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0)
 568         {
 569                 if ($last_id == 0) {
 570                         $last_id = $item['id'];
 571                 }
 572
 573                 $always_bcc = false;
 574                 $is_forum   = false;
 575                 $follower   = '';
 576
 577                 // Check if we should always deliver our stuff via BCC
 578                 if (!empty($item['uid'])) {
 579                         $owner = User::getOwnerDataById($item['uid']);
 580                         if (!empty($owner)) {
 581                                 $always_bcc = $owner['hide-friends'];
 582                                 $is_forum   = ($owner['account-type'] == User::ACCOUNT_TYPE_COMMUNITY) && $owner['manually-approve'];
 583
 584                                 $profile  = APContact::getByURL($owner['url'], false);
 585                                 $follower = $profile['followers'] ?? '';
 586                         }
 587                 }
 588
 589                 if (DI::config()->get('system', 'ap_always_bcc')) {
 590                         $always_bcc = true;
 591                 }
 592
 593                 $parent = Post::selectFirst(['causer-link', 'post-reason'], ['id' => $item['parent']]);
 594                 if (($parent['post-reason'] == Item::PR_ANNOUNCEMENT) && !empty($parent['causer-link'])) {
 595                         $profile = APContact::getByURL($parent['causer-link'], false);
 596                         $is_forum_thread = isset($profile['type']) && $profile['type'] == 'Group';
 597                 } else {
 598                         $is_forum_thread = false;
 599                 }
 600
 601                 if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery') || self::isAPPost($last_id)) {
 602                         // Will be activated in a later step
 603                         $networks = Protocol::FEDERATED;
 604                 } else {
 605                         // For now only send to these contacts:
 606                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 607                 }
 608
 609                 $data = ['to' => [], 'cc' => [], 'bcc' => []];
 610
 611                 if ($item['gravity'] == GRAVITY_PARENT) {
 612                         $actor_profile = APContact::getByURL($item['owner-link']);
 613                 } else {
 614                         $actor_profile = APContact::getByURL($item['author-link']);
 615                 }
 616
 617                 $exclusive = false;
 618
 619                 $terms = Tag::getByURIId($item['uri-id'], [Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
 620
 621                 if ($item['private'] != Item::PRIVATE) {
 622                         // Directly mention the original author upon a quoted reshare.
 623                         // Else just ensure that the original author receives the reshare.
 624                         $announce = self::getAnnounceArray($item);
 625                         if (!empty($announce['comment'])) {
 626                                 $data['to'][] = $announce['actor']['url'];
 627                         } elseif (!empty($announce)) {
 628                                 $data['cc'][] = $announce['actor']['url'];
 629                         }
 630
 631                         $data = array_merge($data, self::fetchPermissionBlockFromThreadParent($item, $is_forum_thread));
 632
 633                         // Check if the item is completely public or unlisted
 634                         if ($item['private'] == Item::PUBLIC) {
 635                                 $data['to'][] = ActivityPub::PUBLIC_COLLECTION;
 636                         } else {
 637                                 $data['cc'][] = ActivityPub::PUBLIC_COLLECTION;
 638                         }
 639
 640                         foreach ($terms as $term) {
 641                                 $profile = APContact::getByURL($term['url'], false);
 642                                 if (!empty($profile)) {
 643                                         if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
 644                                                 $exclusive = true;
 645                                                 if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
 646                                                         $data['cc'][] = $profile['followers'];
 647                                                 }
 648                                         }
 649                                         $data['to'][] = $profile['url'];
 650                                 }
 651                         }
 652                 } else {
 653                         $receiver_list = Item::enumeratePermissions($item, true);
 654
 655                         foreach ($terms as $term) {
 656                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 657                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 658                                         $contact = DBA::selectFirst('contact', ['url', 'network', 'protocol', 'gsid'], ['id' => $cid, 'network' => Protocol::FEDERATED]);
 659                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 660                                                 continue;
 661                                         }
 662
 663                                         $profile = APContact::getByURL($term['url'], false);
 664                                         if (!empty($profile)) {
 665                                                 if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
 666                                                         $exclusive = true;
 667                                                         if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
 668                                                                 $data['cc'][] = $profile['followers'];
 669                                                         }
 670                                                 }
 671                                                 $data['to'][] = $profile['url'];
 672                                         }
 673                                 }
 674                         }
 675
 676                         if ($is_forum && !$exclusive && !empty($follower)) {
 677                                 $data['cc'][] = $follower;
 678                         } elseif (!$exclusive) {
 679                                 foreach ($receiver_list as $receiver) {
 680                                         $contact = DBA::selectFirst('contact', ['url', 'hidden', 'network', 'protocol', 'gsid'], ['id' => $receiver, 'network' => Protocol::FEDERATED]);
 681                                         if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
 682                                                 continue;
 683                                         }
 684
 685                                         if (!empty($profile = APContact::getByURL($contact['url'], false))) {
 686                                                 if ($contact['hidden'] || $always_bcc) {
 687                                                         $data['bcc'][] = $profile['url'];
 688                                                 } else {
 689                                                         $data['cc'][] = $profile['url'];
 690                                                 }
 691                                         }
 692                                 }
 693                         }
 694                 }
 695
 696                 if (!empty($item['parent'])) {
 697                         $parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']], ['order' => ['id']]);
 698                         while ($parent = Post::fetch($parents)) {
 699                                 if ($parent['gravity'] == GRAVITY_PARENT) {
 700                                         $profile = APContact::getByURL($parent['owner-link'], false);
 701                                         if (!empty($profile)) {
 702                                                 if ($item['gravity'] != GRAVITY_PARENT) {
 703                                                         // Comments to forums are directed to the forum
 704                                                         // But comments to forums aren't directed to the followers collection
 705                                                         // This rule is only valid when the actor isn't the forum.
 706                                                         // The forum needs to transmit their content to their followers.
 707                                                         if (($profile['type'] == 'Group') && ($profile['url'] != ($actor_profile['url'] ?? ''))) {
 708                                                                 $data['to'][] = $profile['url'];
 709                                                         } else {
 710                                                                 $data['cc'][] = $profile['url'];
 711                                                                 if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])&& !$is_forum_thread) {
 712                                                                         $data['cc'][] = $actor_profile['followers'];
 713                                                                 }
 714                                                         }
 715                                                 } elseif (!$exclusive && !$is_forum_thread) {
 716                                                         // Public thread parent post always are directed to the followers.
 717                                                         if ($item['private'] != Item::PRIVATE) {
 718                                                                 $data['cc'][] = $actor_profile['followers'];
 719                                                         }
 720                                                 }
 721                                         }
 722                                 }
 723
 724                                 // Don't include data from future posts
 725                                 if ($parent['id'] >= $last_id) {
 726                                         continue;
 727                                 }
 728
 729                                 $profile = APContact::getByURL($parent['author-link'], false);
 730                                 if (!empty($profile)) {
 731                                         if (($profile['type'] == 'Group') || ($parent['uri'] == $item['thr-parent'])) {
 732                                                 $data['to'][] = $profile['url'];
 733                                         } else {
 734                                                 $data['cc'][] = $profile['url'];
 735                                         }
 736                                 }
 737                         }
 738                         DBA::close($parents);
 739                 }
 740
 741                 $data['to'] = array_unique($data['to']);
 742                 $data['cc'] = array_unique($data['cc']);
 743                 $data['bcc'] = array_unique($data['bcc']);
 744
 745                 if (($key = array_search($item['author-link'], $data['to'])) !== false) {
 746                         unset($data['to'][$key]);
 747                 }
 748
 749                 if (($key = array_search($item['author-link'], $data['cc'])) !== false) {
 750                         unset($data['cc'][$key]);
 751                 }
 752
 753                 if (($key = array_search($item['author-link'], $data['bcc'])) !== false) {
 754                         unset($data['bcc'][$key]);
 755                 }
 756
 757                 foreach ($data['to'] as $to) {
 758                         if (($key = array_search($to, $data['cc'])) !== false) {
 759                                 unset($data['cc'][$key]);
 760                         }
 761
 762                         if (($key = array_search($to, $data['bcc'])) !== false) {
 763                                 unset($data['bcc'][$key]);
 764                         }
 765                 }
 766
 767                 foreach ($data['cc'] as $cc) {
 768                         if (($key = array_search($cc, $data['bcc'])) !== false) {
 769                                 unset($data['bcc'][$key]);
 770                         }
 771                 }
 772
 773                 $receivers = ['to' => array_values($data['to']), 'cc' => array_values($data['cc']), 'bcc' => array_values($data['bcc'])];
 774
 775                 if (!$blindcopy) {
 776                         unset($receivers['bcc']);
 777                 }
 778
 779                 foreach (['to' => Tag::TO, 'cc' => Tag::CC, 'bcc' => Tag::BCC] as $element => $type) {
 780                         if (!empty($receivers[$element])) {
 781                                 foreach ($receivers[$element] as $receiver) {
 782                                         if ($receiver == ActivityPub::PUBLIC_COLLECTION) {
 783                                                 $name = Receiver::PUBLIC_COLLECTION;
 784                                         } else {
 785                                                 $name = trim(parse_url($receiver, PHP_URL_PATH), '/');
 786                                         }
 787                                         Tag::store($item['uri-id'], $type, $name, $receiver);
 788                                 }
 789                         }
 790                 }
 791
 792                 return $receivers;
 793         }
 794
 795         /**
 796          * Check if an inbox is archived
 797          *
 798          * @param string $url Inbox url
 799          *
 800          * @return boolean "true" if inbox is archived
 801          */
 802         public static function archivedInbox($url)
 803         {
 804                 return DBA::exists('inbox-status', ['url' => $url, 'archive' => true]);
 805         }
 806
 807         /**
 808          * Check if a given contact should be delivered via AP
 809          *
 810          * @param array $contact
 811          * @param array $networks
 812          * @return bool
 813          * @throws Exception
 814          */
 815         private static function isAPContact(array $contact, array $networks)
 816         {
 817                 if (in_array($contact['network'], $networks) || ($contact['protocol'] == Protocol::ACTIVITYPUB)) {
 818                         return true;
 819                 }
 820
 821                 return GServer::getProtocol($contact['gsid'] ?? 0) == Post\DeliveryData::ACTIVITYPUB;
 822         }
 823
 824         /**
 825          * Fetches a list of inboxes of followers of a given user
 826          *
 827          * @param integer $uid      User ID
 828          * @param boolean $personal fetch personal inboxes
 829          * @param boolean $all_ap   Retrieve all AP enabled inboxes
 830          *
 831          * @return array of follower inboxes
 832          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 833          * @throws \ImagickException
 834          */
 835         public static function fetchTargetInboxesforUser($uid, $personal = false, bool $all_ap = false)
 836         {
 837                 $inboxes = [];
 838
 839                 $isforum = false;
 840
 841                 if (!empty($item['uid'])) {
 842                         $profile = User::getOwnerDataById($item['uid']);
 843                         if (!empty($profile)) {
 844                                 $isforum = $profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY;
 845                         }
 846                 }
 847
 848                 if (DI::config()->get('debug', 'total_ap_delivery') || $all_ap) {
 849                         // Will be activated in a later step
 850                         $networks = Protocol::FEDERATED;
 851                 } else {
 852                         // For now only send to these contacts:
 853                         $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
 854                 }
 855
 856                 $condition = ['uid' => $uid, 'archive' => false, 'pending' => false, 'blocked' => false, 'network' => Protocol::FEDERATED];
 857
 858                 if (!empty($uid)) {
 859                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
 860                 }
 861
 862                 $contacts = DBA::select('contact', ['id', 'url', 'network', 'protocol', 'gsid'], $condition);
 863                 while ($contact = DBA::fetch($contacts)) {
 864                         if (!self::isAPContact($contact, $networks)) {
 865                                 continue;
 866                         }
 867
 868                         if ($isforum && ($contact['network'] == Protocol::DFRN)) {
 869                                 continue;
 870                         }
 871
 872                         if (Network::isUrlBlocked($contact['url'])) {
 873                                 continue;
 874                         }
 875
 876                         $profile = APContact::getByURL($contact['url'], false);
 877                         if (!empty($profile)) {
 878                                 if (empty($profile['sharedinbox']) || $personal || Contact::isLocal($contact['url'])) {
 879                                         $target = $profile['inbox'];
 880                                 } else {
 881                                         $target = $profile['sharedinbox'];
 882                                 }
 883                                 if (!self::archivedInbox($target)) {
 884                                         $inboxes[$target][] = $contact['id'];
 885                                 }
 886                         }
 887                 }
 888                 DBA::close($contacts);
 889
 890                 return $inboxes;
 891         }
 892
 893         /**
 894          * Fetches an array of inboxes for the given item and user
 895          *
 896          * @param array   $item     Item array
 897          * @param integer $uid      User ID
 898          * @param boolean $personal fetch personal inboxes
 899          * @param integer $last_id  Last item id for adding receivers
 900          * @return array with inboxes
 901          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 902          * @throws \ImagickException
 903          */
 904         public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0)
 905         {
 906                 $permissions = self::createPermissionBlockForItem($item, true, $last_id);
 907                 if (empty($permissions)) {
 908                         return [];
 909                 }
 910
 911                 $inboxes = [];
 912
 913                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
 914                         $item_profile = APContact::getByURL($item['author-link'], false);
 915                 } else {
 916                         $item_profile = APContact::getByURL($item['owner-link'], false);
 917                 }
 918
 919                 if (empty($item_profile)) {
 920                         return [];
 921                 }
 922
 923                 $profile_uid = User::getIdForURL($item_profile['url']);
 924
 925                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 926                         if (empty($permissions[$element])) {
 927                                 continue;
 928                         }
 929
 930                         $blindcopy = in_array($element, ['bto', 'bcc']);
 931
 932                         foreach ($permissions[$element] as $receiver) {
 933                                 if (empty($receiver) || Network::isUrlBlocked($receiver)) {
 934                                         continue;
 935                                 }
 936
 937                                 if ($item_profile && ($receiver == $item_profile['followers']) && ($uid == $profile_uid)) {
 938                                         $inboxes = array_merge($inboxes, self::fetchTargetInboxesforUser($uid, $personal, self::isAPPost($last_id)));
 939                                 } else {
 940                                         $profile = APContact::getByURL($receiver, false);
 941                                         if (!empty($profile)) {
 942                                                 $contact = Contact::getByURLForUser($receiver, $uid, false, ['id']);
 943
 944                                                 if (empty($profile['sharedinbox']) || $personal || $blindcopy || Contact::isLocal($receiver)) {
 945                                                         $target = $profile['inbox'];
 946                                                 } else {
 947                                                         $target = $profile['sharedinbox'];
 948                                                 }
 949                                                 if (!self::archivedInbox($target)) {
 950                                                         $inboxes[$target][] = $contact['id'] ?? 0;
 951                                                 }
 952                                         }
 953                                 }
 954                         }
 955                 }
 956
 957                 return $inboxes;
 958         }
 959
 960         /**
 961          * Creates an array in the structure of the item table for a given mail id
 962          *
 963          * @param integer $mail_id
 964          *
 965          * @return array
 966          * @throws \Exception
 967          */
 968         public static function ItemArrayFromMail($mail_id, $use_title = false)
 969         {
 970                 $mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
 971                 if (!DBA::isResult($mail)) {
 972                         return [];
 973                 }
 974
 975                 $reply = DBA::selectFirst('mail', ['uri', 'uri-id', 'from-url'], ['parent-uri' => $mail['parent-uri'], 'reply' => false]);
 976                 if (!DBA::isResult($reply)) {
 977                         $reply = $mail;
 978                 }
 979
 980                 // Making the post more compatible for Mastodon by:
 981                 // - Making it a note and not an article (no title)
 982                 // - Moving the title into the "summary" field that is used as a "content warning"
 983
 984                 if (!$use_title) {
 985                         $mail['body']         = '[abstract]' . $mail['title'] . "[/abstract]\n" . $mail['body'];
 986                         $mail['title']        = '';
 987                 }
 988
 989                 $mail['content-warning']  = '';
 990                 $mail['author-link']      = $mail['owner-link'] = $mail['from-url'];
 991                 $mail['owner-id']         = $mail['author-id'];
 992                 $mail['allow_cid']        = '<'.$mail['contact-id'].'>';
 993                 $mail['allow_gid']        = '';
 994                 $mail['deny_cid']         = '';
 995                 $mail['deny_gid']         = '';
 996                 $mail['private']          = Item::PRIVATE;
 997                 $mail['deleted']          = false;
 998                 $mail['edited']           = $mail['created'];
 999                 $mail['plink']            = DI::baseUrl() . '/message/' . $mail['id'];
1000                 $mail['parent-uri']       = $reply['uri'];
1001                 $mail['parent-uri-id']    = $reply['uri-id'];
1002                 $mail['parent-author-id'] = Contact::getIdForURL($reply['from-url'], 0, false);
1003                 $mail['gravity']          = ($mail['reply'] ? GRAVITY_COMMENT: GRAVITY_PARENT);
1004                 $mail['event-type']       = '';
1005                 $mail['language']         = '';
1006                 $mail['parent']           = 0;
1007
1008                 return $mail;
1009         }
1010
1011         /**
1012          * Creates an activity array for a given mail id
1013          *
1014          * @param integer $mail_id
1015          * @param boolean $object_mode Is the activity item is used inside another object?
1016          *
1017          * @return array of activity
1018          * @throws \Exception
1019          */
1020         public static function createActivityFromMail($mail_id, $object_mode = false)
1021         {
1022                 $mail = self::ItemArrayFromMail($mail_id);
1023                 if (empty($mail)) {
1024                         return [];
1025                 }
1026                 $object = self::createNote($mail);
1027
1028                 if (!$object_mode) {
1029                         $data = ['@context' => ActivityPub::CONTEXT];
1030                 } else {
1031                         $data = [];
1032                 }
1033
1034                 $data['id'] = $mail['uri'] . '/Create';
1035                 $data['type'] = 'Create';
1036                 $data['actor'] = $mail['author-link'];
1037                 $data['published'] = DateTimeFormat::utc($mail['created'] . '+00:00', DateTimeFormat::ATOM);
1038                 $data['instrument'] = self::getService();
1039                 $data = array_merge($data, self::createPermissionBlockForItem($mail, true));
1040
1041                 if (empty($data['to']) && !empty($data['cc'])) {
1042                         $data['to'] = $data['cc'];
1043                 }
1044
1045                 if (empty($data['to']) && !empty($data['bcc'])) {
1046                         $data['to'] = $data['bcc'];
1047                 }
1048
1049                 unset($data['cc']);
1050                 unset($data['bcc']);
1051
1052                 $object['to'] = $data['to'];
1053                 $object['tag'] = [['type' => 'Mention', 'href' => $object['to'][0], 'name' => '']];
1054
1055                 unset($object['cc']);
1056                 unset($object['bcc']);
1057
1058                 $data['directMessage'] = true;
1059
1060                 $data['object'] = $object;
1061
1062                 $owner = User::getOwnerDataById($mail['uid']);
1063
1064                 if (!$object_mode && !empty($owner)) {
1065                         return LDSignature::sign($data, $owner);
1066                 } else {
1067                         return $data;
1068                 }
1069         }
1070
1071         /**
1072          * Returns the activity type of a given item
1073          *
1074          * @param array $item
1075          *
1076          * @return string with activity type
1077          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1078          * @throws \ImagickException
1079          */
1080         private static function getTypeOfItem($item)
1081         {
1082                 $reshared = false;
1083
1084                 // Only check for a reshare, if it is a real reshare and no quoted reshare
1085                 if (strpos($item['body'], "[share") === 0) {
1086                         $announce = self::getAnnounceArray($item);
1087                         $reshared = !empty($announce);
1088                 }
1089
1090                 if ($reshared) {
1091                         $type = 'Announce';
1092                 } elseif ($item['verb'] == Activity::POST) {
1093                         if ($item['created'] == $item['edited']) {
1094                                 $type = 'Create';
1095                         } else {
1096                                 $type = 'Update';
1097                         }
1098                 } elseif ($item['verb'] == Activity::LIKE) {
1099                         $type = 'Like';
1100                 } elseif ($item['verb'] == Activity::DISLIKE) {
1101                         $type = 'Dislike';
1102                 } elseif ($item['verb'] == Activity::ATTEND) {
1103                         $type = 'Accept';
1104                 } elseif ($item['verb'] == Activity::ATTENDNO) {
1105                         $type = 'Reject';
1106                 } elseif ($item['verb'] == Activity::ATTENDMAYBE) {
1107                         $type = 'TentativeAccept';
1108                 } elseif ($item['verb'] == Activity::FOLLOW) {
1109                         $type = 'Follow';
1110                 } elseif ($item['verb'] == Activity::TAG) {
1111                         $type = 'Add';
1112                 } elseif ($item['verb'] == Activity::ANNOUNCE) {
1113                         $type = 'Announce';
1114                 } else {
1115                         $type = '';
1116                 }
1117
1118                 return $type;
1119         }
1120
1121         /**
1122          * Creates the activity or fetches it from the cache
1123          *
1124          * @param integer $item_id
1125          * @param boolean $force Force new cache entry
1126          *
1127          * @return array with the activity
1128          * @throws \Exception
1129          */
1130         public static function createCachedActivityFromItem($item_id, $force = false)
1131         {
1132                 $cachekey = 'APDelivery:createActivity:' . $item_id;
1133
1134                 if (!$force) {
1135                         $data = DI::cache()->get($cachekey);
1136                         if (!is_null($data)) {
1137                                 return $data;
1138                         }
1139                 }
1140
1141                 $data = self::createActivityFromItem($item_id);
1142
1143                 DI::cache()->set($cachekey, $data, Duration::QUARTER_HOUR);
1144                 return $data;
1145         }
1146
1147         /**
1148          * Creates an activity array for a given item id
1149          *
1150          * @param integer $item_id
1151          * @param boolean $object_mode Is the activity item is used inside another object?
1152          *
1153          * @return false|array
1154          * @throws \Exception
1155          */
1156         public static function createActivityFromItem(int $item_id, bool $object_mode = false)
1157         {
1158                 Logger::info('Fetching activity', ['item' => $item_id]);
1159                 $item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
1160                 if (!DBA::isResult($item)) {
1161                         return false;
1162                 }
1163
1164                 if (empty($item['uri-id'])) {
1165                         Logger::warning('Item without uri-id', ['item' => $item]);
1166                         return false;
1167                 }
1168
1169                 if (!$item['deleted']) {
1170                         $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
1171                         $conversation = DBA::selectFirst('conversation', ['source'], $condition);
1172                         if (!$item['origin'] && DBA::isResult($conversation)) {
1173                                 $data = json_decode($conversation['source'], true);
1174                                 if (!empty($data['type'])) {
1175                                         if (in_array($data['type'], ['Create', 'Update'])) {
1176                                                 if ($object_mode) {
1177                                                         unset($data['@context']);
1178                                                         unset($data['signature']);
1179                                                 }
1180                                                 Logger::info('Return stored conversation', ['item' => $item_id]);
1181                                                 return $data;
1182                                         } elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
1183                                                 if (!empty($data['@context'])) {
1184                                                         $context = $data['@context'];
1185                                                         unset($data['@context']);
1186                                                 }
1187                                                 unset($data['actor']);
1188                                                 $object = $data;
1189                                         }
1190                                 }
1191                         }
1192                 }
1193
1194                 $type = self::getTypeOfItem($item);
1195
1196                 if (!$object_mode) {
1197                         $data = ['@context' => $context ?? ActivityPub::CONTEXT];
1198
1199                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
1200                                 $type = 'Undo';
1201                         } elseif ($item['deleted']) {
1202                                 $type = 'Delete';
1203                         }
1204                 } else {
1205                         $data = [];
1206                 }
1207
1208                 if ($type == 'Delete') {
1209                         $data['id'] = Item::newURI($item['uid'], $item['guid']) . '/' . $type;;
1210                 } elseif (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
1211                         $data['id'] = $item['uri'];
1212                 } else {
1213                         $data['id'] = $item['uri'] . '/' . $type;
1214                 }
1215
1216                 $data['type'] = $type;
1217
1218                 if (($type != 'Announce') || ($item['gravity'] != GRAVITY_PARENT)) {
1219                         $data['actor'] = $item['author-link'];
1220                 } else {
1221                         $data['actor'] = $item['owner-link'];
1222                 }
1223
1224                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1225
1226                 $data['instrument'] = self::getService();
1227
1228                 $data = array_merge($data, self::createPermissionBlockForItem($item, false));
1229
1230                 if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
1231                         $data['object'] = $object ?? self::createNote($item);
1232                 } elseif ($data['type'] == 'Add') {
1233                         $data = self::createAddTag($item, $data);
1234                 } elseif ($data['type'] == 'Announce') {
1235                         if ($item['verb'] == ACTIVITY::ANNOUNCE) {
1236                                 $data['object'] = $item['thr-parent'];
1237                         } else {
1238                                 $data = self::createAnnounce($item, $data);
1239                         }
1240                 } elseif ($data['type'] == 'Follow') {
1241                         $data['object'] = $item['parent-uri'];
1242                 } elseif ($data['type'] == 'Undo') {
1243                         $data['object'] = self::createActivityFromItem($item_id, true);
1244                 } else {
1245                         $data['diaspora:guid'] = $item['guid'];
1246                         if (!empty($item['signed_text'])) {
1247                                 $data['diaspora:like'] = $item['signed_text'];
1248                         }
1249                         $data['object'] = $item['thr-parent'];
1250                 }
1251
1252                 if (!empty($item['contact-uid'])) {
1253                         $uid = $item['contact-uid'];
1254                 } else {
1255                         $uid = $item['uid'];
1256                 }
1257
1258                 $owner = User::getOwnerDataById($uid);
1259
1260                 Logger::info('Fetched activity', ['item' => $item_id, 'uid' => $uid]);
1261
1262                 // We don't sign if we aren't the actor. This is important for relaying content especially for forums
1263                 if (!$object_mode && !empty($owner) && ($data['actor'] == $owner['url'])) {
1264                         return LDSignature::sign($data, $owner);
1265                 } else {
1266                         return $data;
1267                 }
1268
1269                 /// @todo Create "conversation" entry
1270         }
1271
1272         /**
1273          * Creates a location entry for a given item array
1274          *
1275          * @param array $item
1276          *
1277          * @return array with location array
1278          */
1279         private static function createLocation($item)
1280         {
1281                 $location = ['type' => 'Place'];
1282
1283                 if (!empty($item['location'])) {
1284                         $location['name'] = $item['location'];
1285                 }
1286
1287                 $coord = [];
1288
1289                 if (empty($item['coord'])) {
1290                         $coord = Map::getCoordinates($item['location']);
1291                 } else {
1292                         $coords = explode(' ', $item['coord']);
1293                         if (count($coords) == 2) {
1294                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
1295                         }
1296                 }
1297
1298                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
1299                         $location['latitude'] = $coord['lat'];
1300                         $location['longitude'] = $coord['lon'];
1301                 }
1302
1303                 return $location;
1304         }
1305
1306         /**
1307          * Returns a tag array for a given item array
1308          *
1309          * @param array $item
1310          *
1311          * @return array of tags
1312          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1313          */
1314         private static function createTagList($item)
1315         {
1316                 $tags = [];
1317
1318                 $terms = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG, Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1319                 foreach ($terms as $term) {
1320                         if ($term['type'] == Tag::HASHTAG) {
1321                                 $url = DI::baseUrl() . '/search?tag=' . urlencode($term['name']);
1322                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['name']];
1323                         } else {
1324                                 $contact = Contact::getByURL($term['url'], false, ['addr']);
1325                                 if (empty($contact)) {
1326                                         continue;
1327                                 }
1328                                 if (!empty($contact['addr'])) {
1329                                         $mention = '@' . $contact['addr'];
1330                                 } else {
1331                                         $mention = '@' . $term['url'];
1332                                 }
1333
1334                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
1335                         }
1336                 }
1337
1338                 $announce = self::getAnnounceArray($item);
1339                 // Mention the original author upon commented reshares
1340                 if (!empty($announce['comment'])) {
1341                         $tags[] = ['type' => 'Mention', 'href' => $announce['actor']['url'], 'name' => '@' . $announce['actor']['addr']];
1342                 }
1343
1344                 return $tags;
1345         }
1346
1347         /**
1348          * Adds attachment data to the JSON document
1349          *
1350          * @param array  $item Data of the item that is to be posted
1351          * @param string $type Object type
1352          *
1353          * @return array with attachment data
1354          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1355          */
1356         private static function createAttachmentList($item, $type)
1357         {
1358                 $attachments = [];
1359
1360                 $uriids = [$item['uri-id']];
1361                 $shared = BBCode::fetchShareAttributes($item['body']);
1362                 if (!empty($shared['guid'])) {
1363                         $shared_item = Post::selectFirst(['uri-id'], ['guid' => $shared['guid']]);
1364                         if (!empty($shared_item['uri-id'])) {
1365                                 $uriids[] = $shared_item['uri-id'];
1366                         }
1367                 }
1368
1369                 $urls = [];
1370                 foreach ($uriids as $uriid) {
1371                         foreach (Post\Media::getByURIId($uriid, [Post\Media::AUDIO, Post\Media::IMAGE, Post\Media::VIDEO, Post\Media::DOCUMENT, Post\Media::TORRENT]) as $attachment) {
1372                                 if (in_array($attachment['url'], $urls)) {
1373                                         continue;
1374                                 }
1375                                 $urls[] = $attachment['url'];
1376
1377                                 $attach = ['type' => 'Document',
1378                                         'mediaType' => $attachment['mimetype'],
1379                                         'url' => $attachment['url'],
1380                                         'name' => $attachment['description']];
1381
1382                                 if (!empty($attachment['height'])) {
1383                                         $attach['height'] = $attachment['height'];
1384                                 }
1385
1386                                 if (!empty($attachment['width'])) {
1387                                         $attach['width'] = $attachment['width'];
1388                                 }
1389
1390                                 if (!empty($attachment['preview'])) {
1391                                         $attach['image'] = $attachment['preview'];
1392                                 }
1393
1394                                 $attachments[] = $attach;
1395                         }
1396                 }
1397
1398                 return $attachments;
1399         }
1400
1401         /**
1402          * Callback function to replace a Friendica style mention in a mention for a summary
1403          *
1404          * @param array $match Matching values for the callback
1405          * @return string Replaced mention
1406          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1407          */
1408         private static function mentionAddrCallback($match)
1409         {
1410                 if (empty($match[1])) {
1411                         return '';
1412                 }
1413
1414                 $data = Contact::getByURL($match[1], false, ['addr']);
1415                 if (empty($data['addr'])) {
1416                         return $match[0];
1417                 }
1418
1419                 return '@' . $data['addr'];
1420         }
1421
1422         /**
1423          * Remove image elements since they are added as attachment
1424          *
1425          * @param string $body
1426          *
1427          * @return string with removed images
1428          */
1429         private static function removePictures($body)
1430         {
1431                 // Simplify image codes
1432                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
1433                 $body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
1434
1435                 // Now remove local links
1436                 $body = preg_replace_callback(
1437                         '/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi',
1438                         function ($match) {
1439                                 // We remove the link when it is a link to a local photo page
1440                                 if (Photo::isLocalPage($match[1])) {
1441                                         return '';
1442                                 }
1443                                 // otherwise we just return the link
1444                                 return '[url]' . $match[1] . '[/url]';
1445                         },
1446                         $body
1447                 );
1448
1449                 // Remove all pictures
1450                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '', $body);
1451
1452                 return $body;
1453         }
1454
1455         /**
1456          * Fetches the "context" value for a givem item array from the "conversation" table
1457          *
1458          * @param array $item
1459          *
1460          * @return string with context url
1461          * @throws \Exception
1462          */
1463         private static function fetchContextURLForItem($item)
1464         {
1465                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
1466                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
1467                         $context_uri = $conversation['conversation-href'];
1468                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
1469                         $context_uri = $conversation['conversation-uri'];
1470                 } else {
1471                         $context_uri = $item['parent-uri'] . '#context';
1472                 }
1473                 return $context_uri;
1474         }
1475
1476         /**
1477          * Returns if the post contains sensitive content ("nsfw")
1478          *
1479          * @param integer $uri_id
1480          *
1481          * @return boolean
1482          * @throws \Exception
1483          */
1484         private static function isSensitive($uri_id)
1485         {
1486                 return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw', 'type' => Tag::HASHTAG]);
1487         }
1488
1489         /**
1490          * Creates event data
1491          *
1492          * @param array $item
1493          *
1494          * @return array with the event data
1495          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1496          */
1497         private static function createEvent($item)
1498         {
1499                 $event = [];
1500                 $event['name'] = $item['event-summary'];
1501                 $event['content'] = BBCode::convertForUriId($item['uri-id'], $item['event-desc'], BBCode::ACTIVITYPUB);
1502                 $event['startTime'] = DateTimeFormat::utc($item['event-start'], 'c');
1503
1504                 if (!$item['event-nofinish']) {
1505                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'], 'c');
1506                 }
1507
1508                 if (!empty($item['event-location'])) {
1509                         $item['location'] = $item['event-location'];
1510                         $event['location'] = self::createLocation($item);
1511                 }
1512
1513                 // 2021.12: Backward compatibility value, all the events now "adjust" to the viewer timezone
1514                 $event['dfrn:adjust'] = true;
1515
1516                 return $event;
1517         }
1518
1519         /**
1520          * Creates a note/article object array
1521          *
1522          * @param array $item
1523          *
1524          * @return array with the object data
1525          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1526          * @throws \ImagickException
1527          */
1528         public static function createNote($item)
1529         {
1530                 if (empty($item)) {
1531                         return [];
1532                 }
1533
1534                 // We are treating posts differently when they are directed to a community.
1535                 // This is done to better support Lemmy. Most of the changes should work with other systems as well.
1536                 // But to not risk compatibility issues we currently perform the changes only for communities.
1537                 if ($item['gravity'] == GRAVITY_PARENT) {
1538                         $isCommunityPost = !empty(Tag::getByURIId($item['uri-id'], [Tag::EXCLUSIVE_MENTION]));
1539                         $links = Post\Media::getByURIId($item['uri-id'], [Post\Media::HTML]);
1540                         if ($isCommunityPost && (count($links) == 1)) {
1541                                 $link = $links[0]['url'];
1542                         }
1543                 } else {
1544                         $isCommunityPost = false;
1545                 }
1546
1547                 if ($item['event-type'] == 'event') {
1548                         $type = 'Event';
1549                 } elseif (!empty($item['title'])) {
1550                         if (!$isCommunityPost || empty($link)) {
1551                                 $type = 'Article';
1552                         } else {
1553                                 // "Page" is used by Lemmy for posts that contain an external link
1554                                 $type = 'Page';
1555                         }
1556                 } else {
1557                         $type = 'Note';
1558                 }
1559
1560                 if ($item['deleted']) {
1561                         $type = 'Tombstone';
1562                 }
1563
1564                 $data = [];
1565                 $data['id'] = $item['uri'];
1566                 $data['type'] = $type;
1567
1568                 if ($item['deleted']) {
1569                         return $data;
1570                 }
1571
1572                 $data['summary'] = BBCode::toPlaintext(BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB));
1573
1574                 if ($item['uri'] != $item['thr-parent']) {
1575                         $data['inReplyTo'] = $item['thr-parent'];
1576                 } else {
1577                         $data['inReplyTo'] = null;
1578                 }
1579
1580                 $data['diaspora:guid'] = $item['guid'];
1581                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1582
1583                 if ($item['created'] != $item['edited']) {
1584                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1585                 }
1586
1587                 $data['url'] = $link ?? $item['plink'];
1588                 $data['attributedTo'] = $item['author-link'];
1589                 $data['sensitive'] = self::isSensitive($item['uri-id']);
1590                 $data['context'] = self::fetchContextURLForItem($item);
1591
1592                 if (!empty($item['title'])) {
1593                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1594                 }
1595
1596                 $permission_block = self::createPermissionBlockForItem($item, false);
1597
1598                 $body = $item['body'];
1599
1600                 if ($type == 'Note') {
1601                         $body = $item['raw-body'] ?? self::removePictures($body);
1602                 }
1603
1604                 /**
1605                  * @todo Improve the automated summary
1606                  * This part is currently deactivated. The automated summary seems to be more
1607                  * confusing than helping. But possibly we will find a better way.
1608                  * So the code is left here for now as a reminder
1609                  *
1610                  * } elseif (($type == 'Article') && empty($data['summary'])) {
1611                  *              $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1612                  *              $summary = preg_replace_callback($regexp, ['self', 'mentionAddrCallback'], $body);
1613                  *              $data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($summary), 1000));
1614                  * }
1615                  */
1616
1617                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1618                         $body = self::prependMentions($body, $item['uri-id'], $item['author-link']);
1619                 }
1620
1621                 if ($type == 'Event') {
1622                         $data = array_merge($data, self::createEvent($item));
1623                 } else {
1624                         if ($isCommunityPost) {
1625                                 // For community posts we remove the visible "!user@domain.tld".
1626                                 // This improves the look at systems like Lemmy.
1627                                 // Also in the future we should control the community delivery via other methods.
1628                                 $body = preg_replace("/!\[url\=[^\[\]]*\][^\[\]]*\[\/url\]/ism", '', $body);
1629                         }
1630
1631                         if ($type == 'Page') {
1632                                 // When we transmit "Page" posts we have to remove the attachment.
1633                                 // The attachment contains the link that we already transmit in the "url" field.
1634                                 $body = preg_replace("/\s*\[attachment .*?\].*?\[\/attachment\]\s*/ism", '', $body);
1635                         }
1636
1637                         $body = BBCode::setMentionsToNicknames($body);
1638
1639                         $data['content'] = BBCode::convertForUriId($item['uri-id'], $body, BBCode::ACTIVITYPUB);
1640                 }
1641
1642                 // The regular "content" field does contain a minimized HTML. This is done since systems like
1643                 // Mastodon has got problems with - for example - embedded pictures.
1644                 // The contentMap does contain the unmodified HTML.
1645                 $language = self::getLanguage($item);
1646                 if (!empty($language)) {
1647                         $richbody = BBCode::setMentionsToNicknames($item['body'] ?? '');
1648                         $richbody = BBCode::removeAttachment($richbody);
1649
1650                         $data['contentMap'][$language] = BBCode::convertForUriId($item['uri-id'], $richbody, BBCode::EXTERNAL);
1651                 }
1652
1653                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1654
1655                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1656                         $data['diaspora:comment'] = $item['signed_text'];
1657                 }
1658
1659                 $data['attachment'] = self::createAttachmentList($item, $type);
1660                 $data['tag'] = self::createTagList($item);
1661
1662                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1663                         $data['location'] = self::createLocation($item);
1664                 }
1665
1666                 if (!empty($item['app'])) {
1667                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1668                 }
1669
1670                 $data = array_merge($data, $permission_block);
1671
1672                 return $data;
1673         }
1674
1675         /**
1676          * Fetches the language from the post, the user or the system.
1677          *
1678          * @param array $item
1679          *
1680          * @return string language string
1681          */
1682         private static function getLanguage(array $item)
1683         {
1684                 // Try to fetch the language from the post itself
1685                 if (!empty($item['language'])) {
1686                         $languages = array_keys(json_decode($item['language'], true));
1687                         if (!empty($languages[0])) {
1688                                 return $languages[0];
1689                         }
1690                 }
1691
1692                 // Otherwise use the user's language
1693                 if (!empty($item['uid'])) {
1694                         $user = DBA::selectFirst('user', ['language'], ['uid' => $item['uid']]);
1695                         if (!empty($user['language'])) {
1696                                 return $user['language'];
1697                         }
1698                 }
1699
1700                 // And finally just use the system language
1701                 return DI::config()->get('system', 'language');
1702         }
1703
1704         /**
1705          * Creates an an "add tag" entry
1706          *
1707          * @param array $item
1708          * @param array $data activity data
1709          *
1710          * @return array with activity data for adding tags
1711          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1712          * @throws \ImagickException
1713          */
1714         private static function createAddTag($item, $data)
1715         {
1716                 $object = XML::parseString($item['object']);
1717                 $target = XML::parseString($item["target"]);
1718
1719                 $data['diaspora:guid'] = $item['guid'];
1720                 $data['actor'] = $item['author-link'];
1721                 $data['target'] = (string)$target->id;
1722                 $data['summary'] = BBCode::toPlaintext($item['body']);
1723                 $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
1724
1725                 return $data;
1726         }
1727
1728         /**
1729          * Creates an announce object entry
1730          *
1731          * @param array $item
1732          * @param array $data activity data
1733          *
1734          * @return array with activity data
1735          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1736          * @throws \ImagickException
1737          */
1738         private static function createAnnounce($item, $data)
1739         {
1740                 $orig_body = $item['body'];
1741                 $announce = self::getAnnounceArray($item);
1742                 if (empty($announce)) {
1743                         $data['type'] = 'Create';
1744                         $data['object'] = self::createNote($item);
1745                         return $data;
1746                 }
1747
1748                 if (empty($announce['comment'])) {
1749                         // Pure announce, without a quote
1750                         $data['type'] = 'Announce';
1751                         $data['object'] = $announce['object']['uri'];
1752                         return $data;
1753                 }
1754
1755                 // Quote
1756                 $data['type'] = 'Create';
1757                 $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
1758                 $data['object'] = self::createNote($item);
1759
1760                 /// @todo Finally descide how to implement this in AP. This is a possible way:
1761                 $data['object']['attachment'][] = self::createNote($announce['object']);
1762
1763                 $data['object']['source']['content'] = $orig_body;
1764                 return $data;
1765         }
1766
1767         /**
1768          * Return announce related data if the item is an annunce
1769          *
1770          * @param array $item
1771          *
1772          * @return array
1773          */
1774         public static function getAnnounceArray($item)
1775         {
1776                 $reshared = Item::getShareArray($item);
1777                 if (empty($reshared['guid'])) {
1778                         return [];
1779                 }
1780
1781                 $reshared_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['guid' => $reshared['guid']]);
1782                 if (!DBA::isResult($reshared_item)) {
1783                         return [];
1784                 }
1785
1786                 if (!in_array($reshared_item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
1787                         return [];
1788                 }
1789
1790                 $profile = APContact::getByURL($reshared_item['author-link'], false);
1791                 if (empty($profile)) {
1792                         return [];
1793                 }
1794
1795                 return ['object' => $reshared_item, 'actor' => $profile, 'comment' => $reshared['comment']];
1796         }
1797
1798         /**
1799          * Checks if the provided item array is an announce
1800          *
1801          * @param array $item
1802          *
1803          * @return boolean
1804          */
1805         public static function isAnnounce($item)
1806         {
1807                 if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
1808                         return true;
1809                 }
1810
1811                 $announce = self::getAnnounceArray($item);
1812                 if (empty($announce)) {
1813                         return false;
1814                 }
1815
1816                 return empty($announce['comment']);
1817         }
1818
1819         /**
1820          * Creates an activity id for a given contact id
1821          *
1822          * @param integer $cid Contact ID of target
1823          *
1824          * @return bool|string activity id
1825          */
1826         public static function activityIDFromContact($cid)
1827         {
1828                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1829                 if (!DBA::isResult($contact)) {
1830                         return false;
1831                 }
1832
1833                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1834                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1835                 return DI::baseUrl() . '/activity/' . $uuid;
1836         }
1837
1838         /**
1839          * Transmits a contact suggestion to a given inbox
1840          *
1841          * @param integer $uid           User ID
1842          * @param string  $inbox         Target inbox
1843          * @param integer $suggestion_id Suggestion ID
1844          *
1845          * @return boolean was the transmission successful?
1846          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1847          */
1848         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1849         {
1850                 $owner = User::getOwnerDataById($uid);
1851
1852                 $suggestion = DI::fsuggest()->selectOneById($suggestion_id);
1853
1854                 $data = ['@context' => ActivityPub::CONTEXT,
1855                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1856                         'type' => 'Announce',
1857                         'actor' => $owner['url'],
1858                         'object' => $suggestion->url,
1859                         'content' => $suggestion->note,
1860                         'instrument' => self::getService(),
1861                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1862                         'cc' => []];
1863
1864                 $signed = LDSignature::sign($data, $owner);
1865
1866                 Logger::info('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1867                 return HTTPSignature::transmit($signed, $inbox, $uid);
1868         }
1869
1870         /**
1871          * Transmits a profile relocation to a given inbox
1872          *
1873          * @param integer $uid   User ID
1874          * @param string  $inbox Target inbox
1875          *
1876          * @return boolean was the transmission successful?
1877          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1878          */
1879         public static function sendProfileRelocation($uid, $inbox)
1880         {
1881                 $owner = User::getOwnerDataById($uid);
1882
1883                 $data = ['@context' => ActivityPub::CONTEXT,
1884                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1885                         'type' => 'dfrn:relocate',
1886                         'actor' => $owner['url'],
1887                         'object' => $owner['url'],
1888                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1889                         'instrument' => self::getService(),
1890                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1891                         'cc' => []];
1892
1893                 $signed = LDSignature::sign($data, $owner);
1894
1895                 Logger::info('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1896                 return HTTPSignature::transmit($signed, $inbox, $uid);
1897         }
1898
1899         /**
1900          * Transmits a profile deletion to a given inbox
1901          *
1902          * @param integer $uid   User ID
1903          * @param string  $inbox Target inbox
1904          *
1905          * @return boolean was the transmission successful?
1906          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1907          */
1908         public static function sendProfileDeletion($uid, $inbox)
1909         {
1910                 $owner = User::getOwnerDataById($uid);
1911
1912                 if (empty($owner)) {
1913                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1914                         return false;
1915                 }
1916
1917                 if (empty($owner['uprvkey'])) {
1918                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1919                         return false;
1920                 }
1921
1922                 $data = ['@context' => ActivityPub::CONTEXT,
1923                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1924                         'type' => 'Delete',
1925                         'actor' => $owner['url'],
1926                         'object' => $owner['url'],
1927                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1928                         'instrument' => self::getService(),
1929                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1930                         'cc' => []];
1931
1932                 $signed = LDSignature::sign($data, $owner);
1933
1934                 Logger::info('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1935                 return HTTPSignature::transmit($signed, $inbox, $uid);
1936         }
1937
1938         /**
1939          * Transmits a profile change to a given inbox
1940          *
1941          * @param integer $uid   User ID
1942          * @param string  $inbox Target inbox
1943          *
1944          * @return boolean was the transmission successful?
1945          * @throws HTTPException\InternalServerErrorException
1946          * @throws HTTPException\NotFoundException
1947          * @throws \ImagickException
1948          */
1949         public static function sendProfileUpdate(int $uid, string $inbox): bool
1950         {
1951                 $owner = User::getOwnerDataById($uid);
1952                 $profile = APContact::getByURL($owner['url']);
1953
1954                 $data = ['@context' => ActivityPub::CONTEXT,
1955                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1956                         'type' => 'Update',
1957                         'actor' => $owner['url'],
1958                         'object' => self::getProfile($uid),
1959                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1960                         'instrument' => self::getService(),
1961                         'to' => [$profile['followers']],
1962                         'cc' => []];
1963
1964                 $signed = LDSignature::sign($data, $owner);
1965
1966                 Logger::info('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1967                 return HTTPSignature::transmit($signed, $inbox, $uid);
1968         }
1969
1970         /**
1971          * Transmits a given activity to a target
1972          *
1973          * @param string  $activity Type name
1974          * @param string  $target   Target profile
1975          * @param integer $uid      User ID
1976          * @return bool
1977          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1978          * @throws \ImagickException
1979          * @throws \Exception
1980          */
1981         public static function sendActivity($activity, $target, $uid, $id = '')
1982         {
1983                 $profile = APContact::getByURL($target);
1984                 if (empty($profile['inbox'])) {
1985                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1986                         return;
1987                 }
1988
1989                 $owner = User::getOwnerDataById($uid);
1990
1991                 if (empty($id)) {
1992                         $id = DI::baseUrl() . '/activity/' . System::createGUID();
1993                 }
1994
1995                 $data = ['@context' => ActivityPub::CONTEXT,
1996                         'id' => $id,
1997                         'type' => $activity,
1998                         'actor' => $owner['url'],
1999                         'object' => $profile['url'],
2000                         'instrument' => self::getService(),
2001                         'to' => [$profile['url']]];
2002
2003                 Logger::info('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid);
2004
2005                 $signed = LDSignature::sign($data, $owner);
2006                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2007         }
2008
2009         /**
2010          * Transmits a "follow object" activity to a target
2011          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
2012          *
2013          * @param string  $object Object URL
2014          * @param string  $target Target profile
2015          * @param integer $uid    User ID
2016          * @return bool
2017          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2018          * @throws \ImagickException
2019          * @throws \Exception
2020          */
2021         public static function sendFollowObject($object, $target, $uid = 0)
2022         {
2023                 $profile = APContact::getByURL($target);
2024                 if (empty($profile['inbox'])) {
2025                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2026                         return;
2027                 }
2028
2029                 if (empty($uid)) {
2030                         // Fetch the list of administrators
2031                         $admin_mail = explode(',', str_replace(' ', '', DI::config()->get('config', 'admin_email')));
2032
2033                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
2034                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
2035                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
2036                         $uid = $first_user['uid'];
2037                 }
2038
2039                 $condition = ['verb' => Activity::FOLLOW, 'uid' => 0, 'parent-uri' => $object,
2040                         'author-id' => Contact::getPublicIdByUserId($uid)];
2041                 if (Post::exists($condition)) {
2042                         Logger::info('Follow for ' . $object . ' for user ' . $uid . ' does already exist.');
2043                         return false;
2044                 }
2045
2046                 $owner = User::getOwnerDataById($uid);
2047
2048                 $data = ['@context' => ActivityPub::CONTEXT,
2049                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2050                         'type' => 'Follow',
2051                         'actor' => $owner['url'],
2052                         'object' => $object,
2053                         'instrument' => self::getService(),
2054                         'to' => [$profile['url']]];
2055
2056                 Logger::info('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid);
2057
2058                 $signed = LDSignature::sign($data, $owner);
2059                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2060         }
2061
2062         /**
2063          * Transmit a message that the contact request had been accepted
2064          *
2065          * @param string  $target Target profile
2066          * @param         $id
2067          * @param integer $uid    User ID
2068          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2069          * @throws \ImagickException
2070          */
2071         public static function sendContactAccept($target, $id, $uid)
2072         {
2073                 $profile = APContact::getByURL($target);
2074                 if (empty($profile['inbox'])) {
2075                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2076                         return;
2077                 }
2078
2079                 $owner = User::getOwnerDataById($uid);
2080                 $data = ['@context' => ActivityPub::CONTEXT,
2081                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2082                         'type' => 'Accept',
2083                         'actor' => $owner['url'],
2084                         'object' => [
2085                                 'id' => (string)$id,
2086                                 'type' => 'Follow',
2087                                 'actor' => $profile['url'],
2088                                 'object' => $owner['url']
2089                         ],
2090                         'instrument' => self::getService(),
2091                         'to' => [$profile['url']]];
2092
2093                 Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2094
2095                 $signed = LDSignature::sign($data, $owner);
2096                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2097         }
2098
2099         /**
2100          * Reject a contact request or terminates the contact relation
2101          *
2102          * @param string  $target Target profile
2103          * @param         $id
2104          * @param integer $uid    User ID
2105          * @return bool Operation success
2106          * @throws HTTPException\InternalServerErrorException
2107          * @throws \ImagickException
2108          */
2109         public static function sendContactReject($target, $id, $uid): bool
2110         {
2111                 $profile = APContact::getByURL($target);
2112                 if (empty($profile['inbox'])) {
2113                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2114                         return false;
2115                 }
2116
2117                 $owner = User::getOwnerDataById($uid);
2118                 $data = ['@context' => ActivityPub::CONTEXT,
2119                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2120                         'type' => 'Reject',
2121                         'actor' => $owner['url'],
2122                         'object' => [
2123                                 'id' => (string)$id,
2124                                 'type' => 'Follow',
2125                                 'actor' => $profile['url'],
2126                                 'object' => $owner['url']
2127                         ],
2128                         'instrument' => self::getService(),
2129                         'to' => [$profile['url']]];
2130
2131                 Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2132
2133                 $signed = LDSignature::sign($data, $owner);
2134                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2135         }
2136
2137         /**
2138          * Transmits a message that we don't want to follow this contact anymore
2139          *
2140          * @param string  $target Target profile
2141          * @param integer $uid    User ID
2142          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2143          * @throws \ImagickException
2144          * @throws \Exception
2145          * @return bool success
2146          */
2147         public static function sendContactUndo($target, $cid, $uid)
2148         {
2149                 $profile = APContact::getByURL($target);
2150                 if (empty($profile['inbox'])) {
2151                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2152                         return false;
2153                 }
2154
2155                 $object_id = self::activityIDFromContact($cid);
2156                 if (empty($object_id)) {
2157                         return false;
2158                 }
2159
2160                 $id = DI::baseUrl() . '/activity/' . System::createGUID();
2161
2162                 $owner = User::getOwnerDataById($uid);
2163                 $data = ['@context' => ActivityPub::CONTEXT,
2164                         'id' => $id,
2165                         'type' => 'Undo',
2166                         'actor' => $owner['url'],
2167                         'object' => ['id' => $object_id, 'type' => 'Follow',
2168                                 'actor' => $owner['url'],
2169                                 'object' => $profile['url']],
2170                         'instrument' => self::getService(),
2171                         'to' => [$profile['url']]];
2172
2173                 Logger::info('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2174
2175                 $signed = LDSignature::sign($data, $owner);
2176                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2177         }
2178
2179         private static function prependMentions($body, int $uriid, string $authorLink)
2180         {
2181                 $mentions = [];
2182
2183                 foreach (Tag::getByURIId($uriid, [Tag::IMPLICIT_MENTION]) as $tag) {
2184                         $profile = Contact::getByURL($tag['url'], false, ['addr', 'contact-type', 'nick']);
2185                         if (!empty($profile['addr'])
2186                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
2187                                 && !strstr($body, $profile['addr'])
2188                                 && !strstr($body, $tag['url'])
2189                                 && $tag['url'] !== $authorLink
2190                         ) {
2191                                 $mentions[] = '@[url=' . $tag['url'] . ']' . $profile['nick'] . '[/url]';
2192                         }
2193                 }
2194
2195                 $mentions[] = $body;
2196
2197                 return implode(' ', $mentions);
2198         }
2199 }