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                         $data['published'] = DateTimeFormat::utcNow(DateTimeFormat::ATOM);
1233                 } elseif ($data['type'] == 'Add') {
1234                         $data = self::createAddTag($item, $data);
1235                 } elseif ($data['type'] == 'Announce') {
1236                         if ($item['verb'] == ACTIVITY::ANNOUNCE) {
1237                                 $data['object'] = $item['thr-parent'];
1238                         } else {
1239                                 $data = self::createAnnounce($item, $data);
1240                         }
1241                 } elseif ($data['type'] == 'Follow') {
1242                         $data['object'] = $item['parent-uri'];
1243                 } elseif ($data['type'] == 'Undo') {
1244                         $data['object'] = self::createActivityFromItem($item_id, true);
1245                 } else {
1246                         $data['diaspora:guid'] = $item['guid'];
1247                         if (!empty($item['signed_text'])) {
1248                                 $data['diaspora:like'] = $item['signed_text'];
1249                         }
1250                         $data['object'] = $item['thr-parent'];
1251                 }
1252
1253                 if (!empty($item['contact-uid'])) {
1254                         $uid = $item['contact-uid'];
1255                 } else {
1256                         $uid = $item['uid'];
1257                 }
1258
1259                 $owner = User::getOwnerDataById($uid);
1260
1261                 Logger::info('Fetched activity', ['item' => $item_id, 'uid' => $uid]);
1262
1263                 // We don't sign if we aren't the actor. This is important for relaying content especially for forums
1264                 if (!$object_mode && !empty($owner) && ($data['actor'] == $owner['url'])) {
1265                         return LDSignature::sign($data, $owner);
1266                 } else {
1267                         return $data;
1268                 }
1269
1270                 /// @todo Create "conversation" entry
1271         }
1272
1273         /**
1274          * Creates a location entry for a given item array
1275          *
1276          * @param array $item
1277          *
1278          * @return array with location array
1279          */
1280         private static function createLocation($item)
1281         {
1282                 $location = ['type' => 'Place'];
1283
1284                 if (!empty($item['location'])) {
1285                         $location['name'] = $item['location'];
1286                 }
1287
1288                 $coord = [];
1289
1290                 if (empty($item['coord'])) {
1291                         $coord = Map::getCoordinates($item['location']);
1292                 } else {
1293                         $coords = explode(' ', $item['coord']);
1294                         if (count($coords) == 2) {
1295                                 $coord = ['lat' => $coords[0], 'lon' => $coords[1]];
1296                         }
1297                 }
1298
1299                 if (!empty($coord['lat']) && !empty($coord['lon'])) {
1300                         $location['latitude'] = $coord['lat'];
1301                         $location['longitude'] = $coord['lon'];
1302                 }
1303
1304                 return $location;
1305         }
1306
1307         /**
1308          * Returns a tag array for a given item array
1309          *
1310          * @param array $item
1311          *
1312          * @return array of tags
1313          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1314          */
1315         private static function createTagList($item)
1316         {
1317                 $tags = [];
1318
1319                 $terms = Tag::getByURIId($item['uri-id'], [Tag::HASHTAG, Tag::MENTION, Tag::IMPLICIT_MENTION, Tag::EXCLUSIVE_MENTION]);
1320                 foreach ($terms as $term) {
1321                         if ($term['type'] == Tag::HASHTAG) {
1322                                 $url = DI::baseUrl() . '/search?tag=' . urlencode($term['name']);
1323                                 $tags[] = ['type' => 'Hashtag', 'href' => $url, 'name' => '#' . $term['name']];
1324                         } else {
1325                                 $contact = Contact::getByURL($term['url'], false, ['addr']);
1326                                 if (empty($contact)) {
1327                                         continue;
1328                                 }
1329                                 if (!empty($contact['addr'])) {
1330                                         $mention = '@' . $contact['addr'];
1331                                 } else {
1332                                         $mention = '@' . $term['url'];
1333                                 }
1334
1335                                 $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
1336                         }
1337                 }
1338
1339                 $announce = self::getAnnounceArray($item);
1340                 // Mention the original author upon commented reshares
1341                 if (!empty($announce['comment'])) {
1342                         $tags[] = ['type' => 'Mention', 'href' => $announce['actor']['url'], 'name' => '@' . $announce['actor']['addr']];
1343                 }
1344
1345                 return $tags;
1346         }
1347
1348         /**
1349          * Adds attachment data to the JSON document
1350          *
1351          * @param array  $item Data of the item that is to be posted
1352          * @param string $type Object type
1353          *
1354          * @return array with attachment data
1355          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1356          */
1357         private static function createAttachmentList($item, $type)
1358         {
1359                 $attachments = [];
1360
1361                 $uriids = [$item['uri-id']];
1362                 $shared = BBCode::fetchShareAttributes($item['body']);
1363                 if (!empty($shared['guid'])) {
1364                         $shared_item = Post::selectFirst(['uri-id'], ['guid' => $shared['guid']]);
1365                         if (!empty($shared_item['uri-id'])) {
1366                                 $uriids[] = $shared_item['uri-id'];
1367                         }
1368                 }
1369
1370                 $urls = [];
1371                 foreach ($uriids as $uriid) {
1372                         foreach (Post\Media::getByURIId($uriid, [Post\Media::AUDIO, Post\Media::IMAGE, Post\Media::VIDEO, Post\Media::DOCUMENT, Post\Media::TORRENT]) as $attachment) {
1373                                 if (in_array($attachment['url'], $urls)) {
1374                                         continue;
1375                                 }
1376                                 $urls[] = $attachment['url'];
1377
1378                                 $attach = ['type' => 'Document',
1379                                         'mediaType' => $attachment['mimetype'],
1380                                         'url' => $attachment['url'],
1381                                         'name' => $attachment['description']];
1382
1383                                 if (!empty($attachment['height'])) {
1384                                         $attach['height'] = $attachment['height'];
1385                                 }
1386
1387                                 if (!empty($attachment['width'])) {
1388                                         $attach['width'] = $attachment['width'];
1389                                 }
1390
1391                                 if (!empty($attachment['preview'])) {
1392                                         $attach['image'] = $attachment['preview'];
1393                                 }
1394
1395                                 $attachments[] = $attach;
1396                         }
1397                 }
1398
1399                 return $attachments;
1400         }
1401
1402         /**
1403          * Callback function to replace a Friendica style mention in a mention for a summary
1404          *
1405          * @param array $match Matching values for the callback
1406          * @return string Replaced mention
1407          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1408          */
1409         private static function mentionAddrCallback($match)
1410         {
1411                 if (empty($match[1])) {
1412                         return '';
1413                 }
1414
1415                 $data = Contact::getByURL($match[1], false, ['addr']);
1416                 if (empty($data['addr'])) {
1417                         return $match[0];
1418                 }
1419
1420                 return '@' . $data['addr'];
1421         }
1422
1423         /**
1424          * Remove image elements since they are added as attachment
1425          *
1426          * @param string $body
1427          *
1428          * @return string with removed images
1429          */
1430         private static function removePictures($body)
1431         {
1432                 // Simplify image codes
1433                 $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
1434                 $body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
1435
1436                 // Now remove local links
1437                 $body = preg_replace_callback(
1438                         '/\[url=([^\[\]]*)\]\[img\](.*)\[\/img\]\[\/url\]/Usi',
1439                         function ($match) {
1440                                 // We remove the link when it is a link to a local photo page
1441                                 if (Photo::isLocalPage($match[1])) {
1442                                         return '';
1443                                 }
1444                                 // otherwise we just return the link
1445                                 return '[url]' . $match[1] . '[/url]';
1446                         },
1447                         $body
1448                 );
1449
1450                 // Remove all pictures
1451                 $body = preg_replace("/\[img\]([^\[\]]*)\[\/img\]/Usi", '', $body);
1452
1453                 return $body;
1454         }
1455
1456         /**
1457          * Fetches the "context" value for a givem item array from the "conversation" table
1458          *
1459          * @param array $item
1460          *
1461          * @return string with context url
1462          * @throws \Exception
1463          */
1464         private static function fetchContextURLForItem($item)
1465         {
1466                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
1467                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
1468                         $context_uri = $conversation['conversation-href'];
1469                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
1470                         $context_uri = $conversation['conversation-uri'];
1471                 } else {
1472                         $context_uri = $item['parent-uri'] . '#context';
1473                 }
1474                 return $context_uri;
1475         }
1476
1477         /**
1478          * Returns if the post contains sensitive content ("nsfw")
1479          *
1480          * @param integer $uri_id
1481          *
1482          * @return boolean
1483          * @throws \Exception
1484          */
1485         private static function isSensitive($uri_id)
1486         {
1487                 return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw', 'type' => Tag::HASHTAG]);
1488         }
1489
1490         /**
1491          * Creates event data
1492          *
1493          * @param array $item
1494          *
1495          * @return array with the event data
1496          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1497          */
1498         private static function createEvent($item)
1499         {
1500                 $event = [];
1501                 $event['name'] = $item['event-summary'];
1502                 $event['content'] = BBCode::convertForUriId($item['uri-id'], $item['event-desc'], BBCode::ACTIVITYPUB);
1503                 $event['startTime'] = DateTimeFormat::utc($item['event-start'], 'c');
1504
1505                 if (!$item['event-nofinish']) {
1506                         $event['endTime'] = DateTimeFormat::utc($item['event-finish'], 'c');
1507                 }
1508
1509                 if (!empty($item['event-location'])) {
1510                         $item['location'] = $item['event-location'];
1511                         $event['location'] = self::createLocation($item);
1512                 }
1513
1514                 // 2021.12: Backward compatibility value, all the events now "adjust" to the viewer timezone
1515                 $event['dfrn:adjust'] = true;
1516
1517                 return $event;
1518         }
1519
1520         /**
1521          * Creates a note/article object array
1522          *
1523          * @param array $item
1524          *
1525          * @return array with the object data
1526          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1527          * @throws \ImagickException
1528          */
1529         public static function createNote($item)
1530         {
1531                 if (empty($item)) {
1532                         return [];
1533                 }
1534
1535                 // We are treating posts differently when they are directed to a community.
1536                 // This is done to better support Lemmy. Most of the changes should work with other systems as well.
1537                 // But to not risk compatibility issues we currently perform the changes only for communities.
1538                 if ($item['gravity'] == GRAVITY_PARENT) {
1539                         $isCommunityPost = !empty(Tag::getByURIId($item['uri-id'], [Tag::EXCLUSIVE_MENTION]));
1540                         $links = Post\Media::getByURIId($item['uri-id'], [Post\Media::HTML]);
1541                         if ($isCommunityPost && (count($links) == 1)) {
1542                                 $link = $links[0]['url'];
1543                         }
1544                 } else {
1545                         $isCommunityPost = false;
1546                 }
1547
1548                 if ($item['event-type'] == 'event') {
1549                         $type = 'Event';
1550                 } elseif (!empty($item['title'])) {
1551                         if (!$isCommunityPost || empty($link)) {
1552                                 $type = 'Article';
1553                         } else {
1554                                 // "Page" is used by Lemmy for posts that contain an external link
1555                                 $type = 'Page';
1556                         }
1557                 } else {
1558                         $type = 'Note';
1559                 }
1560
1561                 if ($item['deleted']) {
1562                         $type = 'Tombstone';
1563                 }
1564
1565                 $data = [];
1566                 $data['id'] = $item['uri'];
1567                 $data['type'] = $type;
1568
1569                 if ($item['deleted']) {
1570                         return $data;
1571                 }
1572
1573                 $data['summary'] = BBCode::toPlaintext(BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB));
1574
1575                 if ($item['uri'] != $item['thr-parent']) {
1576                         $data['inReplyTo'] = $item['thr-parent'];
1577                 } else {
1578                         $data['inReplyTo'] = null;
1579                 }
1580
1581                 $data['diaspora:guid'] = $item['guid'];
1582                 $data['published'] = DateTimeFormat::utc($item['created'] . '+00:00', DateTimeFormat::ATOM);
1583
1584                 if ($item['created'] != $item['edited']) {
1585                         $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
1586                 }
1587
1588                 $data['url'] = $link ?? $item['plink'];
1589                 $data['attributedTo'] = $item['author-link'];
1590                 $data['sensitive'] = self::isSensitive($item['uri-id']);
1591                 $data['context'] = self::fetchContextURLForItem($item);
1592
1593                 if (!empty($item['title'])) {
1594                         $data['name'] = BBCode::toPlaintext($item['title'], false);
1595                 }
1596
1597                 $permission_block = self::createPermissionBlockForItem($item, false);
1598
1599                 $body = $item['body'];
1600
1601                 if ($type == 'Note') {
1602                         $body = $item['raw-body'] ?? self::removePictures($body);
1603                 }
1604
1605                 /**
1606                  * @todo Improve the automated summary
1607                  * This part is currently deactivated. The automated summary seems to be more
1608                  * confusing than helping. But possibly we will find a better way.
1609                  * So the code is left here for now as a reminder
1610                  *
1611                  * } elseif (($type == 'Article') && empty($data['summary'])) {
1612                  *              $regexp = "/[@!]\[url\=([^\[\]]*)\].*?\[\/url\]/ism";
1613                  *              $summary = preg_replace_callback($regexp, ['self', 'mentionAddrCallback'], $body);
1614                  *              $data['summary'] = BBCode::toPlaintext(Plaintext::shorten(self::removePictures($summary), 1000));
1615                  * }
1616                  */
1617
1618                 if (empty($item['uid']) || !Feature::isEnabled($item['uid'], 'explicit_mentions')) {
1619                         $body = self::prependMentions($body, $item['uri-id'], $item['author-link']);
1620                 }
1621
1622                 if ($type == 'Event') {
1623                         $data = array_merge($data, self::createEvent($item));
1624                 } else {
1625                         if ($isCommunityPost) {
1626                                 // For community posts we remove the visible "!user@domain.tld".
1627                                 // This improves the look at systems like Lemmy.
1628                                 // Also in the future we should control the community delivery via other methods.
1629                                 $body = preg_replace("/!\[url\=[^\[\]]*\][^\[\]]*\[\/url\]/ism", '', $body);
1630                         }
1631
1632                         if ($type == 'Page') {
1633                                 // When we transmit "Page" posts we have to remove the attachment.
1634                                 // The attachment contains the link that we already transmit in the "url" field.
1635                                 $body = preg_replace("/\s*\[attachment .*?\].*?\[\/attachment\]\s*/ism", '', $body);
1636                         }
1637
1638                         $body = BBCode::setMentionsToNicknames($body);
1639
1640                         $data['content'] = BBCode::convertForUriId($item['uri-id'], $body, BBCode::ACTIVITYPUB);
1641                 }
1642
1643                 // The regular "content" field does contain a minimized HTML. This is done since systems like
1644                 // Mastodon has got problems with - for example - embedded pictures.
1645                 // The contentMap does contain the unmodified HTML.
1646                 $language = self::getLanguage($item);
1647                 if (!empty($language)) {
1648                         $richbody = BBCode::setMentionsToNicknames($item['body'] ?? '');
1649                         $richbody = BBCode::removeAttachment($richbody);
1650
1651                         $data['contentMap'][$language] = BBCode::convertForUriId($item['uri-id'], $richbody, BBCode::EXTERNAL);
1652                 }
1653
1654                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
1655
1656                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
1657                         $data['diaspora:comment'] = $item['signed_text'];
1658                 }
1659
1660                 $data['attachment'] = self::createAttachmentList($item, $type);
1661                 $data['tag'] = self::createTagList($item);
1662
1663                 if (empty($data['location']) && (!empty($item['coord']) || !empty($item['location']))) {
1664                         $data['location'] = self::createLocation($item);
1665                 }
1666
1667                 if (!empty($item['app'])) {
1668                         $data['generator'] = ['type' => 'Application', 'name' => $item['app']];
1669                 }
1670
1671                 $data = array_merge($data, $permission_block);
1672
1673                 return $data;
1674         }
1675
1676         /**
1677          * Fetches the language from the post, the user or the system.
1678          *
1679          * @param array $item
1680          *
1681          * @return string language string
1682          */
1683         private static function getLanguage(array $item)
1684         {
1685                 // Try to fetch the language from the post itself
1686                 if (!empty($item['language'])) {
1687                         $languages = array_keys(json_decode($item['language'], true));
1688                         if (!empty($languages[0])) {
1689                                 return $languages[0];
1690                         }
1691                 }
1692
1693                 // Otherwise use the user's language
1694                 if (!empty($item['uid'])) {
1695                         $user = DBA::selectFirst('user', ['language'], ['uid' => $item['uid']]);
1696                         if (!empty($user['language'])) {
1697                                 return $user['language'];
1698                         }
1699                 }
1700
1701                 // And finally just use the system language
1702                 return DI::config()->get('system', 'language');
1703         }
1704
1705         /**
1706          * Creates an an "add tag" entry
1707          *
1708          * @param array $item
1709          * @param array $data activity data
1710          *
1711          * @return array with activity data for adding tags
1712          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1713          * @throws \ImagickException
1714          */
1715         private static function createAddTag($item, $data)
1716         {
1717                 $object = XML::parseString($item['object']);
1718                 $target = XML::parseString($item["target"]);
1719
1720                 $data['diaspora:guid'] = $item['guid'];
1721                 $data['actor'] = $item['author-link'];
1722                 $data['target'] = (string)$target->id;
1723                 $data['summary'] = BBCode::toPlaintext($item['body']);
1724                 $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
1725
1726                 return $data;
1727         }
1728
1729         /**
1730          * Creates an announce object entry
1731          *
1732          * @param array $item
1733          * @param array $data activity data
1734          *
1735          * @return array with activity data
1736          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1737          * @throws \ImagickException
1738          */
1739         private static function createAnnounce($item, $data)
1740         {
1741                 $orig_body = $item['body'];
1742                 $announce = self::getAnnounceArray($item);
1743                 if (empty($announce)) {
1744                         $data['type'] = 'Create';
1745                         $data['object'] = self::createNote($item);
1746                         return $data;
1747                 }
1748
1749                 if (empty($announce['comment'])) {
1750                         // Pure announce, without a quote
1751                         $data['type'] = 'Announce';
1752                         $data['object'] = $announce['object']['uri'];
1753                         return $data;
1754                 }
1755
1756                 // Quote
1757                 $data['type'] = 'Create';
1758                 $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
1759                 $data['object'] = self::createNote($item);
1760
1761                 /// @todo Finally descide how to implement this in AP. This is a possible way:
1762                 $data['object']['attachment'][] = self::createNote($announce['object']);
1763
1764                 $data['object']['source']['content'] = $orig_body;
1765                 return $data;
1766         }
1767
1768         /**
1769          * Return announce related data if the item is an annunce
1770          *
1771          * @param array $item
1772          *
1773          * @return array
1774          */
1775         public static function getAnnounceArray($item)
1776         {
1777                 $reshared = Item::getShareArray($item);
1778                 if (empty($reshared['guid'])) {
1779                         return [];
1780                 }
1781
1782                 $reshared_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['guid' => $reshared['guid']]);
1783                 if (!DBA::isResult($reshared_item)) {
1784                         return [];
1785                 }
1786
1787                 if (!in_array($reshared_item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
1788                         return [];
1789                 }
1790
1791                 $profile = APContact::getByURL($reshared_item['author-link'], false);
1792                 if (empty($profile)) {
1793                         return [];
1794                 }
1795
1796                 return ['object' => $reshared_item, 'actor' => $profile, 'comment' => $reshared['comment']];
1797         }
1798
1799         /**
1800          * Checks if the provided item array is an announce
1801          *
1802          * @param array $item
1803          *
1804          * @return boolean
1805          */
1806         public static function isAnnounce($item)
1807         {
1808                 if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
1809                         return true;
1810                 }
1811
1812                 $announce = self::getAnnounceArray($item);
1813                 if (empty($announce)) {
1814                         return false;
1815                 }
1816
1817                 return empty($announce['comment']);
1818         }
1819
1820         /**
1821          * Creates an activity id for a given contact id
1822          *
1823          * @param integer $cid Contact ID of target
1824          *
1825          * @return bool|string activity id
1826          */
1827         public static function activityIDFromContact($cid)
1828         {
1829                 $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
1830                 if (!DBA::isResult($contact)) {
1831                         return false;
1832                 }
1833
1834                 $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
1835                 $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
1836                 return DI::baseUrl() . '/activity/' . $uuid;
1837         }
1838
1839         /**
1840          * Transmits a contact suggestion to a given inbox
1841          *
1842          * @param integer $uid           User ID
1843          * @param string  $inbox         Target inbox
1844          * @param integer $suggestion_id Suggestion ID
1845          *
1846          * @return boolean was the transmission successful?
1847          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1848          */
1849         public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
1850         {
1851                 $owner = User::getOwnerDataById($uid);
1852
1853                 $suggestion = DI::fsuggest()->selectOneById($suggestion_id);
1854
1855                 $data = ['@context' => ActivityPub::CONTEXT,
1856                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1857                         'type' => 'Announce',
1858                         'actor' => $owner['url'],
1859                         'object' => $suggestion->url,
1860                         'content' => $suggestion->note,
1861                         'instrument' => self::getService(),
1862                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1863                         'cc' => []];
1864
1865                 $signed = LDSignature::sign($data, $owner);
1866
1867                 Logger::info('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1868                 return HTTPSignature::transmit($signed, $inbox, $uid);
1869         }
1870
1871         /**
1872          * Transmits a profile relocation to a given inbox
1873          *
1874          * @param integer $uid   User ID
1875          * @param string  $inbox Target inbox
1876          *
1877          * @return boolean was the transmission successful?
1878          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1879          */
1880         public static function sendProfileRelocation($uid, $inbox)
1881         {
1882                 $owner = User::getOwnerDataById($uid);
1883
1884                 $data = ['@context' => ActivityPub::CONTEXT,
1885                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1886                         'type' => 'dfrn:relocate',
1887                         'actor' => $owner['url'],
1888                         'object' => $owner['url'],
1889                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1890                         'instrument' => self::getService(),
1891                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1892                         'cc' => []];
1893
1894                 $signed = LDSignature::sign($data, $owner);
1895
1896                 Logger::info('Deliver profile relocation for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1897                 return HTTPSignature::transmit($signed, $inbox, $uid);
1898         }
1899
1900         /**
1901          * Transmits a profile deletion to a given inbox
1902          *
1903          * @param integer $uid   User ID
1904          * @param string  $inbox Target inbox
1905          *
1906          * @return boolean was the transmission successful?
1907          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1908          */
1909         public static function sendProfileDeletion($uid, $inbox)
1910         {
1911                 $owner = User::getOwnerDataById($uid);
1912
1913                 if (empty($owner)) {
1914                         Logger::error('No owner data found, the deletion message cannot be processed.', ['user' => $uid]);
1915                         return false;
1916                 }
1917
1918                 if (empty($owner['uprvkey'])) {
1919                         Logger::error('No private key for owner found, the deletion message cannot be processed.', ['user' => $uid]);
1920                         return false;
1921                 }
1922
1923                 $data = ['@context' => ActivityPub::CONTEXT,
1924                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1925                         'type' => 'Delete',
1926                         'actor' => $owner['url'],
1927                         'object' => $owner['url'],
1928                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1929                         'instrument' => self::getService(),
1930                         'to' => [ActivityPub::PUBLIC_COLLECTION],
1931                         'cc' => []];
1932
1933                 $signed = LDSignature::sign($data, $owner);
1934
1935                 Logger::info('Deliver profile deletion for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1936                 return HTTPSignature::transmit($signed, $inbox, $uid);
1937         }
1938
1939         /**
1940          * Transmits a profile change to a given inbox
1941          *
1942          * @param integer $uid   User ID
1943          * @param string  $inbox Target inbox
1944          *
1945          * @return boolean was the transmission successful?
1946          * @throws HTTPException\InternalServerErrorException
1947          * @throws HTTPException\NotFoundException
1948          * @throws \ImagickException
1949          */
1950         public static function sendProfileUpdate(int $uid, string $inbox): bool
1951         {
1952                 $owner = User::getOwnerDataById($uid);
1953                 $profile = APContact::getByURL($owner['url']);
1954
1955                 $data = ['@context' => ActivityPub::CONTEXT,
1956                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
1957                         'type' => 'Update',
1958                         'actor' => $owner['url'],
1959                         'object' => self::getProfile($uid),
1960                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
1961                         'instrument' => self::getService(),
1962                         'to' => [$profile['followers']],
1963                         'cc' => []];
1964
1965                 $signed = LDSignature::sign($data, $owner);
1966
1967                 Logger::info('Deliver profile update for user ' . $uid . ' to ' . $inbox . ' via ActivityPub');
1968                 return HTTPSignature::transmit($signed, $inbox, $uid);
1969         }
1970
1971         /**
1972          * Transmits a given activity to a target
1973          *
1974          * @param string  $activity Type name
1975          * @param string  $target   Target profile
1976          * @param integer $uid      User ID
1977          * @return bool
1978          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
1979          * @throws \ImagickException
1980          * @throws \Exception
1981          */
1982         public static function sendActivity($activity, $target, $uid, $id = '')
1983         {
1984                 $profile = APContact::getByURL($target);
1985                 if (empty($profile['inbox'])) {
1986                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
1987                         return;
1988                 }
1989
1990                 $owner = User::getOwnerDataById($uid);
1991
1992                 if (empty($id)) {
1993                         $id = DI::baseUrl() . '/activity/' . System::createGUID();
1994                 }
1995
1996                 $data = ['@context' => ActivityPub::CONTEXT,
1997                         'id' => $id,
1998                         'type' => $activity,
1999                         'actor' => $owner['url'],
2000                         'object' => $profile['url'],
2001                         'instrument' => self::getService(),
2002                         'to' => [$profile['url']]];
2003
2004                 Logger::info('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid);
2005
2006                 $signed = LDSignature::sign($data, $owner);
2007                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2008         }
2009
2010         /**
2011          * Transmits a "follow object" activity to a target
2012          * This is a preparation for sending automated "follow" requests when receiving "Announce" messages
2013          *
2014          * @param string  $object Object URL
2015          * @param string  $target Target profile
2016          * @param integer $uid    User ID
2017          * @return bool
2018          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2019          * @throws \ImagickException
2020          * @throws \Exception
2021          */
2022         public static function sendFollowObject($object, $target, $uid = 0)
2023         {
2024                 $profile = APContact::getByURL($target);
2025                 if (empty($profile['inbox'])) {
2026                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2027                         return;
2028                 }
2029
2030                 if (empty($uid)) {
2031                         // Fetch the list of administrators
2032                         $admin_mail = explode(',', str_replace(' ', '', DI::config()->get('config', 'admin_email')));
2033
2034                         // We need to use some user as a sender. It doesn't care who it will send. We will use an administrator account.
2035                         $condition = ['verified' => true, 'blocked' => false, 'account_removed' => false, 'account_expired' => false, 'email' => $admin_mail];
2036                         $first_user = DBA::selectFirst('user', ['uid'], $condition);
2037                         $uid = $first_user['uid'];
2038                 }
2039
2040                 $condition = ['verb' => Activity::FOLLOW, 'uid' => 0, 'parent-uri' => $object,
2041                         'author-id' => Contact::getPublicIdByUserId($uid)];
2042                 if (Post::exists($condition)) {
2043                         Logger::info('Follow for ' . $object . ' for user ' . $uid . ' does already exist.');
2044                         return false;
2045                 }
2046
2047                 $owner = User::getOwnerDataById($uid);
2048
2049                 $data = ['@context' => ActivityPub::CONTEXT,
2050                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2051                         'type' => 'Follow',
2052                         'actor' => $owner['url'],
2053                         'object' => $object,
2054                         'instrument' => self::getService(),
2055                         'to' => [$profile['url']]];
2056
2057                 Logger::info('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid);
2058
2059                 $signed = LDSignature::sign($data, $owner);
2060                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2061         }
2062
2063         /**
2064          * Transmit a message that the contact request had been accepted
2065          *
2066          * @param string  $target Target profile
2067          * @param         $id
2068          * @param integer $uid    User ID
2069          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2070          * @throws \ImagickException
2071          */
2072         public static function sendContactAccept($target, $id, $uid)
2073         {
2074                 $profile = APContact::getByURL($target);
2075                 if (empty($profile['inbox'])) {
2076                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2077                         return;
2078                 }
2079
2080                 $owner = User::getOwnerDataById($uid);
2081                 $data = ['@context' => ActivityPub::CONTEXT,
2082                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2083                         'type' => 'Accept',
2084                         'actor' => $owner['url'],
2085                         'object' => [
2086                                 'id' => (string)$id,
2087                                 'type' => 'Follow',
2088                                 'actor' => $profile['url'],
2089                                 'object' => $owner['url']
2090                         ],
2091                         'instrument' => self::getService(),
2092                         'to' => [$profile['url']]];
2093
2094                 Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2095
2096                 $signed = LDSignature::sign($data, $owner);
2097                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2098         }
2099
2100         /**
2101          * Reject a contact request or terminates the contact relation
2102          *
2103          * @param string  $target Target profile
2104          * @param         $id
2105          * @param integer $uid    User ID
2106          * @return bool Operation success
2107          * @throws HTTPException\InternalServerErrorException
2108          * @throws \ImagickException
2109          */
2110         public static function sendContactReject($target, $id, $uid): bool
2111         {
2112                 $profile = APContact::getByURL($target);
2113                 if (empty($profile['inbox'])) {
2114                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2115                         return false;
2116                 }
2117
2118                 $owner = User::getOwnerDataById($uid);
2119                 $data = ['@context' => ActivityPub::CONTEXT,
2120                         'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
2121                         'type' => 'Reject',
2122                         'actor' => $owner['url'],
2123                         'object' => [
2124                                 'id' => (string)$id,
2125                                 'type' => 'Follow',
2126                                 'actor' => $profile['url'],
2127                                 'object' => $owner['url']
2128                         ],
2129                         'instrument' => self::getService(),
2130                         'to' => [$profile['url']]];
2131
2132                 Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2133
2134                 $signed = LDSignature::sign($data, $owner);
2135                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2136         }
2137
2138         /**
2139          * Transmits a message that we don't want to follow this contact anymore
2140          *
2141          * @param string  $target Target profile
2142          * @param integer $uid    User ID
2143          * @throws \Friendica\Network\HTTPException\InternalServerErrorException
2144          * @throws \ImagickException
2145          * @throws \Exception
2146          * @return bool success
2147          */
2148         public static function sendContactUndo($target, $cid, $uid)
2149         {
2150                 $profile = APContact::getByURL($target);
2151                 if (empty($profile['inbox'])) {
2152                         Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
2153                         return false;
2154                 }
2155
2156                 $object_id = self::activityIDFromContact($cid);
2157                 if (empty($object_id)) {
2158                         return false;
2159                 }
2160
2161                 $id = DI::baseUrl() . '/activity/' . System::createGUID();
2162
2163                 $owner = User::getOwnerDataById($uid);
2164                 $data = ['@context' => ActivityPub::CONTEXT,
2165                         'id' => $id,
2166                         'type' => 'Undo',
2167                         'actor' => $owner['url'],
2168                         'object' => ['id' => $object_id, 'type' => 'Follow',
2169                                 'actor' => $owner['url'],
2170                                 'object' => $profile['url']],
2171                         'instrument' => self::getService(),
2172                         'to' => [$profile['url']]];
2173
2174                 Logger::info('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id);
2175
2176                 $signed = LDSignature::sign($data, $owner);
2177                 return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
2178         }
2179
2180         private static function prependMentions($body, int $uriid, string $authorLink)
2181         {
2182                 $mentions = [];
2183
2184                 foreach (Tag::getByURIId($uriid, [Tag::IMPLICIT_MENTION]) as $tag) {
2185                         $profile = Contact::getByURL($tag['url'], false, ['addr', 'contact-type', 'nick']);
2186                         if (!empty($profile['addr'])
2187                                 && $profile['contact-type'] != Contact::TYPE_COMMUNITY
2188                                 && !strstr($body, $profile['addr'])
2189                                 && !strstr($body, $tag['url'])
2190                                 && $tag['url'] !== $authorLink
2191                         ) {
2192                                 $mentions[] = '@[url=' . $tag['url'] . ']' . $profile['nick'] . '[/url]';
2193                         }
2194                 }
2195
2196                 $mentions[] = $body;
2197
2198                 return implode(' ', $mentions);
2199         }
2200 }