src/Protocol/ActivityPub.php

   1 <?php
   2 /**
   3  * @file src/Protocol/ActivityPub.php
   4  */
   5 namespace Friendica\Protocol;
   6
   7 use Friendica\Database\DBA;
   8 use Friendica\Core\System;
   9 use Friendica\BaseObject;
  10 use Friendica\Util\Network;
  11 use Friendica\Util\HTTPSignature;
  12 use Friendica\Core\Protocol;
  13 use Friendica\Model\Conversation;
  14 use Friendica\Model\Contact;
  15 use Friendica\Model\APContact;
  16 use Friendica\Model\Item;
  17 use Friendica\Model\Profile;
  18 use Friendica\Model\Term;
  19 use Friendica\Model\User;
  20 use Friendica\Util\DateTimeFormat;
  21 use Friendica\Util\Crypto;
  22 use Friendica\Content\Text\BBCode;
  23 use Friendica\Content\Text\HTML;
  24 use Friendica\Util\JsonLD;
  25 use Friendica\Util\LDSignature;
  26 use Friendica\Core\Config;
  27
  28 /**
  29  * @brief ActivityPub Protocol class
  30  * The ActivityPub Protocol is a message exchange protocol defined by the W3C.
  31  * https://www.w3.org/TR/activitypub/
  32  * https://www.w3.org/TR/activitystreams-core/
  33  * https://www.w3.org/TR/activitystreams-vocabulary/
  34  *
  35  * https://blog.joinmastodon.org/2018/06/how-to-implement-a-basic-activitypub-server/
  36  * https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/
  37  *
  38  * Digest: https://tools.ietf.org/html/rfc5843
  39  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  40  *
  41  * Mastodon implementation of supported activities:
  42  * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  43  *
  44  * To-do:
  45  *
  46  * Receiver:
  47  * - Update (Image, Video, Article, Note)
  48  * - Event
  49  * - Undo Announce
  50  *
  51  * Check what this is meant to do:
  52  * - Add
  53  * - Block
  54  * - Flag
  55  * - Remove
  56  * - Undo Block
  57  * - Undo Accept (Problem: This could invert a contact accept or an event accept)
  58  *
  59  * Transmitter:
  60  * - Event
  61  *
  62  * Complicated:
  63  * - Announce
  64  * - Undo Announce
  65  *
  66  * General:
  67  * - Attachments
  68  * - nsfw (sensitive)
  69  * - Queueing unsucessful deliveries
  70  * - Polling the outboxes for missing content?
  71  * - Possibly using the LD-JSON parser
  72  */
  73 class ActivityPub
  74 {
  75         const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
  76         const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
  77                 ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
  78                 'diaspora' => 'https://diasporafoundation.org/ns/',
  79                 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
  80                 'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag']];
  81         const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
  82         const CONTENT_TYPES = ['Note', 'Article', 'Video', 'Image'];
  83         const ACTIVITY_TYPES = ['Like', 'Dislike', 'Accept', 'Reject', 'TentativeAccept'];
  84         /**
  85          * @brief Checks if the web request is done for the AP protocol
  86          *
  87          * @return is it AP?
  88          */
  89         public static function isRequest()
  90         {
  91                 return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
  92                         stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
  93         }
  94
  95         /**
  96          * Return the ActivityPub profile of the given user
  97          *
  98          * @param integer $uid User ID
  99          * @return profile array
 100          */
 101         public static function profile($uid)
 102         {
 103                 $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
 104                         'account_removed' => false, 'verified' => true];
 105                 $fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
 106                 $user = DBA::selectFirst('user', $fields, $condition);
 107                 if (!DBA::isResult($user)) {
 108                         return [];
 109                 }
 110
 111                 $fields = ['locality', 'region', 'country-name'];
 112                 $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid, 'is-default' => true]);
 113                 if (!DBA::isResult($profile)) {
 114                         return [];
 115                 }
 116
 117                 $fields = ['name', 'url', 'location', 'about', 'avatar'];
 118                 $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
 119                 if (!DBA::isResult($contact)) {
 120                         return [];
 121                 }
 122
 123                 $data = ['@context' => self::CONTEXT];
 124                 $data['id'] = $contact['url'];
 125                 $data['diaspora:guid'] = $user['guid'];
 126                 $data['type'] = self::ACCOUNT_TYPES[$user['account-type']];
 127                 $data['following'] = System::baseUrl() . '/following/' . $user['nickname'];
 128                 $data['followers'] = System::baseUrl() . '/followers/' . $user['nickname'];
 129                 $data['inbox'] = System::baseUrl() . '/inbox/' . $user['nickname'];
 130                 $data['outbox'] = System::baseUrl() . '/outbox/' . $user['nickname'];
 131                 $data['preferredUsername'] = $user['nickname'];
 132                 $data['name'] = $contact['name'];
 133                 $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
 134                         'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
 135                 $data['summary'] = $contact['about'];
 136                 $data['url'] = $contact['url'];
 137                 $data['manuallyApprovesFollowers'] = in_array($user['page-flags'], [Contact::PAGE_NORMAL, Contact::PAGE_PRVGROUP]);
 138                 $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
 139                         'owner' => $contact['url'],
 140                         'publicKeyPem' => $user['pubkey']];
 141                 $data['endpoints'] = ['sharedInbox' => System::baseUrl() . '/inbox'];
 142                 $data['icon'] = ['type' => 'Image',
 143                         'url' => $contact['avatar']];
 144
 145                 // tags: https://kitty.town/@inmysocks/100656097926961126.json
 146                 return $data;
 147         }
 148
 149         /**
 150          * @brief Returns an array with permissions of a given item array
 151          *
 152          * @param array $item
 153          *
 154          * @return array with permissions
 155          */
 156         private static function fetchPermissionBlockFromConversation($item)
 157         {
 158                 if (empty($item['thr-parent'])) {
 159                         return [];
 160                 }
 161
 162                 $condition = ['item-uri' => $item['thr-parent'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 163                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 164                 if (!DBA::isResult($conversation)) {
 165                         return [];
 166                 }
 167
 168                 $activity = json_decode($conversation['source'], true);
 169
 170                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 171                 $profile = APContact::getByURL($actor);
 172
 173                 $item_profile = APContact::getByURL($item['author-link']);
 174                 $exclude[] = $item['author-link'];
 175
 176                 if ($item['gravity'] == GRAVITY_PARENT) {
 177                         $exclude[] = $item['owner-link'];
 178                 }
 179
 180                 $permissions['to'][] = $actor;
 181
 182                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 183                         if (empty($activity[$element])) {
 184                                 continue;
 185                         }
 186                         if (is_string($activity[$element])) {
 187                                 $activity[$element] = [$activity[$element]];
 188                         }
 189
 190                         foreach ($activity[$element] as $receiver) {
 191                                 if ($receiver == $profile['followers'] && !empty($item_profile['followers'])) {
 192                                         $receiver = $item_profile['followers'];
 193                                 }
 194                                 if (!in_array($receiver, $exclude)) {
 195                                         $permissions[$element][] = $receiver;
 196                                 }
 197                         }
 198                 }
 199                 return $permissions;
 200         }
 201
 202         /**
 203          * @brief Creates an array of permissions from an item thread
 204          *
 205          * @param array $item
 206          *
 207          * @return permission array
 208          */
 209         public static function createPermissionBlockForItem($item)
 210         {
 211                 $data = ['to' => [], 'cc' => []];
 212
 213                 $data = array_merge($data, self::fetchPermissionBlockFromConversation($item));
 214
 215                 $actor_profile = APContact::getByURL($item['author-link']);
 216
 217                 $terms = Term::tagArrayFromItemId($item['id'], TERM_MENTION);
 218
 219                 $contacts[$item['author-link']] = $item['author-link'];
 220
 221                 if (!$item['private']) {
 222                         $data['to'][] = self::PUBLIC_COLLECTION;
 223                         if (!empty($actor_profile['followers'])) {
 224                                 $data['cc'][] = $actor_profile['followers'];
 225                         }
 226
 227                         foreach ($terms as $term) {
 228                                 $profile = APContact::getByURL($term['url'], false);
 229                                 if (!empty($profile) && empty($contacts[$profile['url']])) {
 230                                         $data['cc'][] = $profile['url'];
 231                                         $contacts[$profile['url']] = $profile['url'];
 232                                 }
 233                         }
 234                 } else {
 235                         $receiver_list = Item::enumeratePermissions($item);
 236
 237                         $mentioned = [];
 238
 239                         foreach ($terms as $term) {
 240                                 $cid = Contact::getIdForURL($term['url'], $item['uid']);
 241                                 if (!empty($cid) && in_array($cid, $receiver_list)) {
 242                                         $contact = DBA::selectFirst('contact', ['url'], ['id' => $cid, 'network' => Protocol::ACTIVITYPUB]);
 243                                         $data['to'][] = $contact['url'];
 244                                         $contacts[$contact['url']] = $contact['url'];
 245                                 }
 246                         }
 247
 248                         foreach ($receiver_list as $receiver) {
 249                                 $contact = DBA::selectFirst('contact', ['url'], ['id' => $receiver, 'network' => Protocol::ACTIVITYPUB]);
 250                                 if (empty($contacts[$contact['url']])) {
 251                                         $data['cc'][] = $contact['url'];
 252                                         $contacts[$contact['url']] = $contact['url'];
 253                                 }
 254                         }
 255                 }
 256
 257                 $parents = Item::select(['id', 'author-link', 'owner-link', 'gravity'], ['parent' => $item['parent']]);
 258                 while ($parent = Item::fetch($parents)) {
 259                         // Don't include data from future posts
 260                         if ($parent['id'] >= $item['id']) {
 261                                 continue;
 262                         }
 263
 264                         $profile = APContact::getByURL($parent['author-link'], false);
 265                         if (!empty($profile) && empty($contacts[$profile['url']])) {
 266                                 $data['cc'][] = $profile['url'];
 267                                 $contacts[$profile['url']] = $profile['url'];
 268                         }
 269
 270                         if ($item['gravity'] != GRAVITY_PARENT) {
 271                                 continue;
 272                         }
 273
 274                         $profile = APContact::getByURL($parent['owner-link'], false);
 275                         if (!empty($profile) && empty($contacts[$profile['url']])) {
 276                                 $data['cc'][] = $profile['url'];
 277                                 $contacts[$profile['url']] = $profile['url'];
 278                         }
 279                 }
 280                 DBA::close($parents);
 281
 282                 if (empty($data['to'])) {
 283                         $data['to'] = $data['cc'];
 284                         $data['cc'] = [];
 285                 }
 286
 287                 return $data;
 288         }
 289
 290         /**
 291          * @brief Fetches a list of inboxes of followers of a given user
 292          *
 293          * @param integer $uid User ID
 294          *
 295          * @return array of follower inboxes
 296          */
 297         public static function fetchTargetInboxesforUser($uid)
 298         {
 299                 $inboxes = [];
 300
 301                 $condition = ['uid' => $uid, 'network' => Protocol::ACTIVITYPUB, 'archive' => false, 'pending' => false];
 302
 303                 if (!empty($uid)) {
 304                         $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
 305                 }
 306
 307                 $contacts = DBA::select('contact', ['notify', 'batch'], $condition);
 308                 while ($contact = DBA::fetch($contacts)) {
 309                         $contact = defaults($contact, 'batch', $contact['notify']);
 310                         $inboxes[$contact] = $contact;
 311                 }
 312                 DBA::close($contacts);
 313
 314                 return $inboxes;
 315         }
 316
 317         /**
 318          * @brief Fetches an array of inboxes for the given item and user
 319          *
 320          * @param array $item
 321          * @param integer $uid User ID
 322          *
 323          * @return array with inboxes
 324          */
 325         public static function fetchTargetInboxes($item, $uid)
 326         {
 327                 $permissions = self::createPermissionBlockForItem($item);
 328                 if (empty($permissions)) {
 329                         return [];
 330                 }
 331
 332                 $inboxes = [];
 333
 334                 if ($item['gravity'] == GRAVITY_ACTIVITY) {
 335                         $item_profile = APContact::getByURL($item['author-link']);
 336                 } else {
 337                         $item_profile = APContact::getByURL($item['owner-link']);
 338                 }
 339
 340                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
 341                         if (empty($permissions[$element])) {
 342                                 continue;
 343                         }
 344
 345                         foreach ($permissions[$element] as $receiver) {
 346                                 if ($receiver == $item_profile['followers']) {
 347                                         $inboxes = self::fetchTargetInboxesforUser($uid);
 348                                 } else {
 349                                         $profile = APContact::getByURL($receiver);
 350                                         if (!empty($profile)) {
 351                                                 $target = defaults($profile, 'sharedinbox', $profile['inbox']);
 352                                                 $inboxes[$target] = $target;
 353                                         }
 354                                 }
 355                         }
 356                 }
 357
 358                 return $inboxes;
 359         }
 360
 361         /**
 362          * @brief Returns the activity type of a given item
 363          *
 364          * @param array $item
 365          *
 366          * @return activity type
 367          */
 368         public static function getTypeOfItem($item)
 369         {
 370                 if ($item['verb'] == ACTIVITY_POST) {
 371                         if ($item['created'] == $item['edited']) {
 372                                 $type = 'Create';
 373                         } else {
 374                                 $type = 'Update';
 375                         }
 376                 } elseif ($item['verb'] == ACTIVITY_LIKE) {
 377                         $type = 'Like';
 378                 } elseif ($item['verb'] == ACTIVITY_DISLIKE) {
 379                         $type = 'Dislike';
 380                 } elseif ($item['verb'] == ACTIVITY_ATTEND) {
 381                         $type = 'Accept';
 382                 } elseif ($item['verb'] == ACTIVITY_ATTENDNO) {
 383                         $type = 'Reject';
 384                 } elseif ($item['verb'] == ACTIVITY_ATTENDMAYBE) {
 385                         $type = 'TentativeAccept';
 386                 } else {
 387                         $type = '';
 388                 }
 389
 390                 return $type;
 391         }
 392
 393         /**
 394          * @brief Creates an activity array for a given item id
 395          *
 396          * @param integer $item_id
 397          * @param boolean $object_mode Is the activity item is used inside another object?
 398          *
 399          * @return array of activity
 400          */
 401         public static function createActivityFromItem($item_id, $object_mode = false)
 402         {
 403                 $item = Item::selectFirst([], ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
 404
 405                 if (!DBA::isResult($item)) {
 406                         return false;
 407                 }
 408
 409                 $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
 410                 $conversation = DBA::selectFirst('conversation', ['source'], $condition);
 411                 if (DBA::isResult($conversation)) {
 412                         $data = json_decode($conversation['source']);
 413                         if (!empty($data)) {
 414                                 return $data;
 415                         }
 416                 }
 417
 418                 $type = self::getTypeOfItem($item);
 419
 420                 if (!$object_mode) {
 421                         $data = ['@context' => self::CONTEXT];
 422
 423                         if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
 424                                 $type = 'Undo';
 425                         } elseif ($item['deleted']) {
 426                                 $type = 'Delete';
 427                         }
 428                 } else {
 429                         $data = [];
 430                 }
 431
 432                 $data['id'] = $item['uri'] . '#' . $type;
 433                 $data['type'] = $type;
 434                 $data['actor'] = $item['author-link'];
 435
 436                 $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
 437
 438                 if ($item["created"] != $item["edited"]) {
 439                         $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 440                 }
 441
 442                 $data['context'] = self::fetchContextURLForItem($item);
 443
 444                 $data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
 445
 446                 if (in_array($data['type'], ['Create', 'Update', 'Announce', 'Delete'])) {
 447                         $data['object'] = self::createNote($item);
 448                 } elseif ($data['type'] == 'Undo') {
 449                         $data['object'] = self::createActivityFromItem($item_id, true);
 450                 } else {
 451                         $data['object'] = $item['thr-parent'];
 452                 }
 453
 454                 $owner = User::getOwnerDataById($item['uid']);
 455
 456                 if (!$object_mode) {
 457                         return LDSignature::sign($data, $owner);
 458                 } else {
 459                         return $data;
 460                 }
 461         }
 462
 463         /**
 464          * @brief Creates an object array for a given item id
 465          *
 466          * @param integer $item_id
 467          *
 468          * @return object array
 469          */
 470         public static function createObjectFromItemID($item_id)
 471         {
 472                 $item = Item::selectFirst([], ['id' => $item_id, 'parent-network' => Protocol::NATIVE_SUPPORT]);
 473
 474                 if (!DBA::isResult($item)) {
 475                         return false;
 476                 }
 477
 478                 $data = ['@context' => self::CONTEXT];
 479                 $data = array_merge($data, self::createNote($item));
 480
 481                 return $data;
 482         }
 483
 484         /**
 485          * @brief Returns a tag array for a given item array
 486          *
 487          * @param array $item
 488          *
 489          * @return array of tags
 490          */
 491         private static function createTagList($item)
 492         {
 493                 $tags = [];
 494
 495                 $terms = Term::tagArrayFromItemId($item['id'], TERM_MENTION);
 496                 foreach ($terms as $term) {
 497                         $contact = Contact::getDetailsByURL($term['url']);
 498                         if (!empty($contact['addr'])) {
 499                                 $mention = '@' . $contact['addr'];
 500                         } else {
 501                                 $mention = '@' . $term['url'];
 502                         }
 503
 504                         $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
 505                 }
 506                 return $tags;
 507         }
 508
 509         /**
 510          * @brief Fetches the "context" value for a givem item array from the "conversation" table
 511          *
 512          * @param array $item
 513          *
 514          * @return string with context url
 515          */
 516         private static function fetchContextURLForItem($item)
 517         {
 518                 $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
 519                 if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
 520                         $context_uri = $conversation['conversation-href'];
 521                 } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
 522                         $context_uri = $conversation['conversation-uri'];
 523                 } else {
 524                         $context_uri = str_replace('/objects/', '/context/', $item['parent-uri']);
 525                 }
 526                 return $context_uri;
 527         }
 528
 529         /**
 530          * @brief Creates a note/article object array
 531          *
 532          * @param array $item
 533          *
 534          * @return object array
 535          */
 536         private static function createNote($item)
 537         {
 538                 if (!empty($item['title'])) {
 539                         $type = 'Article';
 540                 } else {
 541                         $type = 'Note';
 542                 }
 543
 544                 if ($item['deleted']) {
 545                         $type = 'Tombstone';
 546                 }
 547
 548                 $data = [];
 549                 $data['id'] = $item['uri'];
 550                 $data['type'] = $type;
 551
 552                 if ($item['deleted']) {
 553                         return $data;
 554                 }
 555
 556                 $data['summary'] = null; // Ignore by now
 557
 558                 if ($item['uri'] != $item['thr-parent']) {
 559                         $data['inReplyTo'] = $item['thr-parent'];
 560                 } else {
 561                         $data['inReplyTo'] = null;
 562                 }
 563
 564                 $data['diaspora:guid'] = $item['guid'];
 565                 $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
 566
 567                 if ($item["created"] != $item["edited"]) {
 568                         $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
 569                 }
 570
 571                 $data['url'] = $item['plink'];
 572                 $data['attributedTo'] = $item['author-link'];
 573                 $data['actor'] = $item['author-link'];
 574                 $data['sensitive'] = false; // - Query NSFW
 575                 $data['context'] = self::fetchContextURLForItem($item);
 576
 577                 if (!empty($item['title'])) {
 578                         $data['name'] = BBCode::convert($item['title'], false, 7);
 579                 }
 580
 581                 $data['content'] = BBCode::convert($item['body'], false, 7);
 582                 $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
 583
 584                 if (!empty($item['signed_text']) && ($item['uri'] != $item['thr-parent'])) {
 585                         $data['diaspora:comment'] = $item['signed_text'];
 586                 }
 587
 588                 $data['attachment'] = []; // @ToDo
 589                 $data['tag'] = self::createTagList($item);
 590                 $data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
 591
 592                 return $data;
 593         }
 594
 595         /**
 596          * @brief Transmits a profile deletion to a given inbox
 597          *
 598          * @param integer $uid User ID
 599          * @param string $inbox Target inbox
 600          */
 601         public static function transmitProfileDeletion($uid, $inbox)
 602         {
 603                 $owner = User::getOwnerDataById($uid);
 604                 $profile = APContact::getByURL($owner['url']);
 605
 606                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 607                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 608                         'type' => 'Delete',
 609                         'actor' => $owner['url'],
 610                         'object' => self::profile($uid),
 611                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 612                         'to' => [self::PUBLIC_COLLECTION],
 613                         'cc' => []];
 614
 615                 $signed = LDSignature::sign($data, $owner);
 616
 617                 logger('Deliver profile deletion for user ' . $uid . ' to ' . $inbox .' via ActivityPub', LOGGER_DEBUG);
 618                 HTTPSignature::transmit($signed, $inbox, $uid);
 619         }
 620
 621         /**
 622          * @brief Transmits a profile change to a given inbox
 623          *
 624          * @param integer $uid User ID
 625          * @param string $inbox Target inbox
 626          */
 627         public static function transmitProfileUpdate($uid, $inbox)
 628         {
 629                 $owner = User::getOwnerDataById($uid);
 630                 $profile = APContact::getByURL($owner['url']);
 631
 632                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 633                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 634                         'type' => 'Update',
 635                         'actor' => $owner['url'],
 636                         'object' => self::profile($uid),
 637                         'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
 638                         'to' => [$profile['followers']],
 639                         'cc' => []];
 640
 641                 $signed = LDSignature::sign($data, $owner);
 642
 643                 logger('Deliver profile update for user ' . $uid . ' to ' . $inbox .' via ActivityPub', LOGGER_DEBUG);
 644                 HTTPSignature::transmit($signed, $inbox, $uid);
 645         }
 646
 647         /**
 648          * @brief Transmits a given activity to a target
 649          *
 650          * @param array $activity
 651          * @param string $target Target profile
 652          * @param integer $uid User ID
 653          */
 654         public static function transmitActivity($activity, $target, $uid)
 655         {
 656                 $profile = APContact::getByURL($target);
 657
 658                 $owner = User::getOwnerDataById($uid);
 659
 660                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 661                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 662                         'type' => $activity,
 663                         'actor' => $owner['url'],
 664                         'object' => $profile['url'],
 665                         'to' => $profile['url']];
 666
 667                 logger('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, LOGGER_DEBUG);
 668
 669                 $signed = LDSignature::sign($data, $owner);
 670                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
 671         }
 672
 673         /**
 674          * @brief Transmit a message that the contact request had been accepted
 675          *
 676          * @param string $target Target profile
 677          * @param $id
 678          * @param integer $uid User ID
 679          */
 680         public static function transmitContactAccept($target, $id, $uid)
 681         {
 682                 $profile = APContact::getByURL($target);
 683
 684                 $owner = User::getOwnerDataById($uid);
 685                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 686                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 687                         'type' => 'Accept',
 688                         'actor' => $owner['url'],
 689                         'object' => ['id' => $id, 'type' => 'Follow',
 690                                 'actor' => $profile['url'],
 691                                 'object' => $owner['url']],
 692                         'to' => $profile['url']];
 693
 694                 logger('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 695
 696                 $signed = LDSignature::sign($data, $owner);
 697                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
 698         }
 699
 700         /**
 701          * @brief
 702          *
 703          * @param string $target Target profile
 704          * @param $id
 705          * @param integer $uid User ID
 706          */
 707         public static function transmitContactReject($target, $id, $uid)
 708         {
 709                 $profile = APContact::getByURL($target);
 710
 711                 $owner = User::getOwnerDataById($uid);
 712                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 713                         'id' => System::baseUrl() . '/activity/' . System::createGUID(),
 714                         'type' => 'Reject',
 715                         'actor' => $owner['url'],
 716                         'object' => ['id' => $id, 'type' => 'Follow',
 717                                 'actor' => $profile['url'],
 718                                 'object' => $owner['url']],
 719                         'to' => $profile['url']];
 720
 721                 logger('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 722
 723                 $signed = LDSignature::sign($data, $owner);
 724                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
 725         }
 726
 727         /**
 728          * @brief
 729          *
 730          * @param string $target Target profile
 731          * @param integer $uid User ID
 732          */
 733         public static function transmitContactUndo($target, $uid)
 734         {
 735                 $profile = APContact::getByURL($target);
 736
 737                 $id = System::baseUrl() . '/activity/' . System::createGUID();
 738
 739                 $owner = User::getOwnerDataById($uid);
 740                 $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
 741                         'id' => $id,
 742                         'type' => 'Undo',
 743                         'actor' => $owner['url'],
 744                         'object' => ['id' => $id, 'type' => 'Follow',
 745                                 'actor' => $owner['url'],
 746                                 'object' => $profile['url']],
 747                         'to' => $profile['url']];
 748
 749                 logger('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
 750
 751                 $signed = LDSignature::sign($data, $owner);
 752                 HTTPSignature::transmit($signed, $profile['inbox'], $uid);
 753         }
 754
 755         /**
 756          * Fetches ActivityPub content from the given url
 757          *
 758          * @param string $url content url
 759          * @return array
 760          */
 761         public static function fetchContent($url)
 762         {
 763                 $ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
 764                 if (!$ret['success'] || empty($ret['body'])) {
 765                         return false;
 766                 }
 767
 768                 return json_decode($ret['body'], true);
 769         }
 770
 771         /**
 772          * Fetches a profile from the given url into an array that is compatible to Probe::uri
 773          *
 774          * @param string $url profile url
 775          * @return array
 776          */
 777         public static function probeProfile($url)
 778         {
 779                 $apcontact = APContact::getByURL($url, true);
 780                 if (empty($apcontact)) {
 781                         return false;
 782                 }
 783
 784                 $profile = ['network' => Protocol::ACTIVITYPUB];
 785                 $profile['nick'] = $apcontact['nick'];
 786                 $profile['name'] = $apcontact['name'];
 787                 $profile['guid'] = $apcontact['uuid'];
 788                 $profile['url'] = $apcontact['url'];
 789                 $profile['addr'] = $apcontact['addr'];
 790                 $profile['alias'] = $apcontact['alias'];
 791                 $profile['photo'] = $apcontact['photo'];
 792                 // $profile['community']
 793                 // $profile['keywords']
 794                 // $profile['location']
 795                 $profile['about'] = $apcontact['about'];
 796                 $profile['batch'] = $apcontact['sharedinbox'];
 797                 $profile['notify'] = $apcontact['inbox'];
 798                 $profile['poll'] = $apcontact['outbox'];
 799                 $profile['pubkey'] = $apcontact['pubkey'];
 800                 $profile['baseurl'] = $apcontact['baseurl'];
 801
 802                 // Remove all "null" fields
 803                 foreach ($profile as $field => $content) {
 804                         if (is_null($content)) {
 805                                 unset($profile[$field]);
 806                         }
 807                 }
 808
 809                 return $profile;
 810         }
 811
 812         /**
 813          * @brief
 814          *
 815          * @param $body
 816          * @param $header
 817          * @param integer $uid User ID
 818          */
 819         public static function processInbox($body, $header, $uid)
 820         {
 821                 $http_signer = HTTPSignature::getSigner($body, $header);
 822                 if (empty($http_signer)) {
 823                         logger('Invalid HTTP signature, message will be discarded.', LOGGER_DEBUG);
 824                         return;
 825                 } else {
 826                         logger('HTTP signature is signed by ' . $http_signer, LOGGER_DEBUG);
 827                 }
 828
 829                 $activity = json_decode($body, true);
 830
 831                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 832                 logger('Message for user ' . $uid . ' is from actor ' . $actor, LOGGER_DEBUG);
 833
 834                 if (empty($activity)) {
 835                         logger('Invalid body.', LOGGER_DEBUG);
 836                         return;
 837                 }
 838
 839                 if (LDSignature::isSigned($activity)) {
 840                         $ld_signer = LDSignature::getSigner($activity);
 841                         if (empty($ld_signer)) {
 842                                 logger('Invalid JSON-LD signature from ' . $actor, LOGGER_DEBUG);
 843                         }
 844                         if (!empty($ld_signer && ($actor == $http_signer))) {
 845                                 logger('The HTTP and the JSON-LD signature belong to ' . $ld_signer, LOGGER_DEBUG);
 846                                 $trust_source = true;
 847                         } elseif (!empty($ld_signer)) {
 848                                 logger('JSON-LD signature is signed by ' . $ld_signer, LOGGER_DEBUG);
 849                                 $trust_source = true;
 850                         } elseif ($actor == $http_signer) {
 851                                 logger('Bad JSON-LD signature, but HTTP signer fits the actor.', LOGGER_DEBUG);
 852                                 $trust_source = true;
 853                         } else {
 854                                 logger('Invalid JSON-LD signature and the HTTP signer is different.', LOGGER_DEBUG);
 855                                 $trust_source = false;
 856                         }
 857                 } elseif ($actor == $http_signer) {
 858                         logger('Trusting post without JSON-LD signature, The actor fits the HTTP signer.', LOGGER_DEBUG);
 859                         $trust_source = true;
 860                 } else {
 861                         logger('No JSON-LD signature, different actor.', LOGGER_DEBUG);
 862                         $trust_source = false;
 863                 }
 864
 865                 self::processActivity($activity, $body, $uid, $trust_source);
 866         }
 867
 868         /**
 869          * @brief
 870          *
 871          * @param $url
 872          * @param integer $uid User ID
 873          */
 874         public static function fetchOutbox($url, $uid)
 875         {
 876                 $data = self::fetchContent($url);
 877                 if (empty($data)) {
 878                         return;
 879                 }
 880
 881                 if (!empty($data['orderedItems'])) {
 882                         $items = $data['orderedItems'];
 883                 } elseif (!empty($data['first']['orderedItems'])) {
 884                         $items = $data['first']['orderedItems'];
 885                 } elseif (!empty($data['first'])) {
 886                         self::fetchOutbox($data['first'], $uid);
 887                         return;
 888                 } else {
 889                         $items = [];
 890                 }
 891
 892                 foreach ($items as $activity) {
 893                         self::processActivity($activity, '', $uid, true);
 894                 }
 895         }
 896
 897         /**
 898          * @brief
 899          *
 900          * @param array $activity
 901          * @param integer $uid User ID
 902          * @param $trust_source
 903          *
 904          * @return
 905          */
 906         private static function prepareObjectData($activity, $uid, &$trust_source)
 907         {
 908                 $actor = JsonLD::fetchElement($activity, 'actor', 'id');
 909                 if (empty($actor)) {
 910                         logger('Empty actor', LOGGER_DEBUG);
 911                         return [];
 912                 }
 913
 914                 // Fetch all receivers from to, cc, bto and bcc
 915                 $receivers = self::getReceivers($activity, $actor);
 916
 917                 // When it is a delivery to a personal inbox we add that user to the receivers
 918                 if (!empty($uid)) {
 919                         $owner = User::getOwnerDataById($uid);
 920                         $additional = ['uid:' . $uid => $uid];
 921                         $receivers = array_merge($receivers, $additional);
 922                 }
 923
 924                 logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
 925
 926                 $object_id = JsonLD::fetchElement($activity, 'object', 'id');
 927                 if (empty($object_id)) {
 928                         logger('No object found', LOGGER_DEBUG);
 929                         return [];
 930                 }
 931
 932                 // Fetch the content only on activities where this matters
 933                 if (in_array($activity['type'], ['Create', 'Announce'])) {
 934                         $object_data = self::fetchObject($object_id, $activity['object'], $trust_source);
 935                         if (empty($object_data)) {
 936                                 logger("Object data couldn't be processed", LOGGER_DEBUG);
 937                                 return [];
 938                         }
 939                         // We had been able to retrieve the object data - so we can trust the source
 940                         $trust_source = true;
 941                 } elseif (in_array($activity['type'], ['Like', 'Dislike'])) {
 942                         // Create a mostly empty array out of the activity data (instead of the object).
 943                         // This way we later don't have to check for the existence of ech individual array element.
 944                         $object_data = self::processObject($activity);
 945                         $object_data['name'] = $activity['type'];
 946                         $object_data['author'] = $activity['actor'];
 947                         $object_data['object'] = $object_id;
 948                         $object_data['object_type'] = ''; // Since we don't fetch the object, we don't know the type
 949                 } else {
 950                         $object_data = [];
 951                         $object_data['id'] = $activity['id'];
 952                         $object_data['object'] = $activity['object'];
 953                         $object_data['object_type'] = JsonLD::fetchElement($activity, 'object', 'type');
 954                 }
 955
 956                 $object_data = self::addActivityFields($object_data, $activity);
 957
 958                 $object_data['type'] = $activity['type'];
 959                 $object_data['owner'] = $actor;
 960                 $object_data['receiver'] = array_merge(defaults($object_data, 'receiver', []), $receivers);
 961
 962                 logger('Processing ' . $object_data['type'] . ' ' . $object_data['object_type'] . ' ' . $object_data['id'], LOGGER_DEBUG);
 963
 964                 return $object_data;
 965         }
 966
 967         /**
 968          * @brief
 969          *
 970          * @param array $activity
 971          * @param $body
 972          * @param integer $uid User ID
 973          * @param $trust_source
 974          */
 975         private static function processActivity($activity, $body = '', $uid = null, $trust_source = false)
 976         {
 977                 if (empty($activity['type'])) {
 978                         logger('Empty type', LOGGER_DEBUG);
 979                         return;
 980                 }
 981
 982                 if (empty($activity['object'])) {
 983                         logger('Empty object', LOGGER_DEBUG);
 984                         return;
 985                 }
 986
 987                 if (empty($activity['actor'])) {
 988                         logger('Empty actor', LOGGER_DEBUG);
 989                         return;
 990
 991                 }
 992
 993                 // $trust_source is called by reference and is set to true if the content was retrieved successfully
 994                 $object_data = self::prepareObjectData($activity, $uid, $trust_source);
 995                 if (empty($object_data)) {
 996                         logger('No object data found', LOGGER_DEBUG);
 997                         return;
 998                 }
 999
1000                 if (!$trust_source) {
1001                         logger('No trust for activity type "' . $activity['type'] . '", so we quit now.', LOGGER_DEBUG);
1002                 }
1003
1004                 switch ($activity['type']) {
1005                         case 'Create':
1006                         case 'Announce':
1007                                 self::createItem($object_data, $body);
1008                                 break;
1009
1010                         case 'Like':
1011                                 self::likeItem($object_data, $body);
1012                                 break;
1013
1014                         case 'Dislike':
1015                                 self::dislikeItem($object_data, $body);
1016                                 break;
1017
1018                         case 'Update':
1019                                 if (in_array($object_data['object_type'], self::CONTENT_TYPES)) {
1020                                         /// @todo
1021                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
1022                                         self::updatePerson($object_data, $body);
1023                                 }
1024                                 break;
1025
1026                         case 'Delete':
1027                                 if ($object_data['object_type'] == 'Tombstone') {
1028                                         self::deleteItem($object_data, $body);
1029                                 } elseif (in_array($object_data['object_type'], self::ACCOUNT_TYPES)) {
1030                                         self::deletePerson($object_data, $body);
1031                                 }
1032                                 break;
1033
1034                         case 'Follow':
1035                                 self::followUser($object_data);
1036                                 break;
1037
1038                         case 'Accept':
1039                                 if ($object_data['object_type'] == 'Follow') {
1040                                         self::acceptFollowUser($object_data);
1041                                 }
1042                                 break;
1043
1044                         case 'Reject':
1045                                 if ($object_data['object_type'] == 'Follow') {
1046                                         self::rejectFollowUser($object_data);
1047                                 }
1048                                 break;
1049
1050                         case 'Undo':
1051                                 if ($object_data['object_type'] == 'Follow') {
1052                                         self::undoFollowUser($object_data);
1053                                 } elseif (in_array($object_data['object_type'], self::ACTIVITY_TYPES)) {
1054                                         self::undoActivity($object_data);
1055                                 }
1056                                 break;
1057
1058                         default:
1059                                 logger('Unknown activity: ' . $activity['type'], LOGGER_DEBUG);
1060                                 break;
1061                 }
1062         }
1063
1064         /**
1065          * @brief
1066          *
1067          * @param array $activity
1068          * @param $actor
1069          *
1070          * @return
1071          */
1072         private static function getReceivers($activity, $actor)
1073         {
1074                 $receivers = [];
1075
1076                 // When it is an answer, we inherite the receivers from the parent
1077                 $replyto = JsonLD::fetchElement($activity, 'inReplyTo', 'id');
1078                 if (!empty($replyto)) {
1079                         $parents = Item::select(['uid'], ['uri' => $replyto]);
1080                         while ($parent = Item::fetch($parents)) {
1081                                 $receivers['uid:' . $parent['uid']] = $parent['uid'];
1082                         }
1083                 }
1084
1085                 if (!empty($actor)) {
1086                         $profile = APContact::getByURL($actor);
1087                         $followers = defaults($profile, 'followers', '');
1088
1089                         logger('Actor: ' . $actor . ' - Followers: ' . $followers, LOGGER_DEBUG);
1090                 } else {
1091                         logger('Empty actor', LOGGER_DEBUG);
1092                         $followers = '';
1093                 }
1094
1095                 foreach (['to', 'cc', 'bto', 'bcc'] as $element) {
1096                         if (empty($activity[$element])) {
1097                                 continue;
1098                         }
1099
1100                         // The receiver can be an array or a string
1101                         if (is_string($activity[$element])) {
1102                                 $activity[$element] = [$activity[$element]];
1103                         }
1104
1105                         foreach ($activity[$element] as $receiver) {
1106                                 if ($receiver == self::PUBLIC_COLLECTION) {
1107                                         $receivers['uid:0'] = 0;
1108                                 }
1109
1110                                 if (($receiver == self::PUBLIC_COLLECTION) && !empty($actor)) {
1111                                         // This will most likely catch all OStatus connections to Mastodon
1112                                         $condition = ['alias' => [$actor, normalise_link($actor)], 'rel' => [Contact::SHARING, Contact::FRIEND]
1113                                                 , 'archive' => false, 'pending' => false];
1114                                         $contacts = DBA::select('contact', ['uid'], $condition);
1115                                         while ($contact = DBA::fetch($contacts)) {
1116                                                 if ($contact['uid'] != 0) {
1117                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
1118                                                 }
1119                                         }
1120                                         DBA::close($contacts);
1121                                 }
1122
1123                                 if (in_array($receiver, [$followers, self::PUBLIC_COLLECTION]) && !empty($actor)) {
1124                                         $condition = ['nurl' => normalise_link($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
1125                                                 'network' => Protocol::ACTIVITYPUB, 'archive' => false, 'pending' => false];
1126                                         $contacts = DBA::select('contact', ['uid'], $condition);
1127                                         while ($contact = DBA::fetch($contacts)) {
1128                                                 if ($contact['uid'] != 0) {
1129                                                         $receivers['uid:' . $contact['uid']] = $contact['uid'];
1130                                                 }
1131                                         }
1132                                         DBA::close($contacts);
1133                                         continue;
1134                                 }
1135
1136                                 $condition = ['self' => true, 'nurl' => normalise_link($receiver)];
1137                                 $contact = DBA::selectFirst('contact', ['uid'], $condition);
1138                                 if (!DBA::isResult($contact)) {
1139                                         continue;
1140                                 }
1141                                 $receivers['uid:' . $contact['uid']] = $contact['uid'];
1142                         }
1143                 }
1144
1145                 self::switchContacts($receivers, $actor);
1146
1147                 return $receivers;
1148         }
1149
1150         /**
1151          * @brief
1152          *
1153          * @param $cid
1154          * @param integer $uid User ID
1155          * @param $url
1156          */
1157         private static function switchContact($cid, $uid, $url)
1158         {
1159                 $profile = ActivityPub::probeProfile($url);
1160                 if (empty($profile)) {
1161                         return;
1162                 }
1163
1164                 logger('Switch contact ' . $cid . ' (' . $profile['url'] . ') for user ' . $uid . ' from OStatus to ActivityPub');
1165
1166                 $photo = $profile['photo'];
1167                 unset($profile['photo']);
1168                 unset($profile['baseurl']);
1169
1170                 $profile['nurl'] = normalise_link($profile['url']);
1171                 DBA::update('contact', $profile, ['id' => $cid]);
1172
1173                 Contact::updateAvatar($photo, $uid, $cid);
1174         }
1175
1176         /**
1177          * @brief
1178          *
1179          * @param $receivers
1180          * @param $actor
1181          */
1182         private static function switchContacts($receivers, $actor)
1183         {
1184                 if (empty($actor)) {
1185                         return;
1186                 }
1187
1188                 foreach ($receivers as $receiver) {
1189                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'nurl' => normalise_link($actor)]);
1190                         if (DBA::isResult($contact)) {
1191                                 self::switchContact($contact['id'], $receiver, $actor);
1192                         }
1193
1194                         $contact = DBA::selectFirst('contact', ['id'], ['uid' => $receiver, 'network' => Protocol::OSTATUS, 'alias' => [normalise_link($actor), $actor]]);
1195                         if (DBA::isResult($contact)) {
1196                                 self::switchContact($contact['id'], $receiver, $actor);
1197                         }
1198                 }
1199         }
1200
1201         /**
1202          * @brief
1203          *
1204          * @param $object_data
1205          * @param array $activity
1206          *
1207          * @return
1208          */
1209         private static function addActivityFields($object_data, $activity)
1210         {
1211                 if (!empty($activity['published']) && empty($object_data['published'])) {
1212                         $object_data['published'] = $activity['published'];
1213                 }
1214
1215                 if (!empty($activity['updated']) && empty($object_data['updated'])) {
1216                         $object_data['updated'] = $activity['updated'];
1217                 }
1218
1219                 if (!empty($activity['inReplyTo']) && empty($object_data['parent-uri'])) {
1220                         $object_data['parent-uri'] = JsonLD::fetchElement($activity, 'inReplyTo', 'id');
1221                 }
1222
1223                 if (!empty($activity['instrument'])) {
1224                         $object_data['service'] = JsonLD::fetchElement($activity, 'instrument', 'name', 'type', 'Service');
1225                 }
1226                 return $object_data;
1227         }
1228
1229         /**
1230          * @brief
1231          *
1232          * @param $object_id
1233          * @param $object
1234          * @param $trust_source
1235          *
1236          * @return
1237          */
1238         private static function fetchObject($object_id, $object = [], $trust_source = false)
1239         {
1240                 if (!$trust_source || is_string($object)) {
1241                         $data = self::fetchContent($object_id);
1242                         if (empty($data)) {
1243                                 logger('Empty content for ' . $object_id . ', check if content is available locally.', LOGGER_DEBUG);
1244                                 $data = $object_id;
1245                         } else {
1246                                 logger('Fetched content for ' . $object_id, LOGGER_DEBUG);
1247                         }
1248                 } else {
1249                         logger('Using original object for url ' . $object_id, LOGGER_DEBUG);
1250                         $data = $object;
1251                 }
1252
1253                 if (is_string($data)) {
1254                         $item = Item::selectFirst([], ['uri' => $data]);
1255                         if (!DBA::isResult($item)) {
1256                                 logger('Object with url ' . $data . ' was not found locally.', LOGGER_DEBUG);
1257                                 return false;
1258                         }
1259                         logger('Using already stored item for url ' . $object_id, LOGGER_DEBUG);
1260                         $data = self::createNote($item);
1261                 }
1262
1263                 if (empty($data['type'])) {
1264                         logger('Empty type', LOGGER_DEBUG);
1265                         return false;
1266                 }
1267
1268                 if (in_array($data['type'], self::CONTENT_TYPES)) {
1269                         return self::processObject($data);
1270                 }
1271
1272                 if ($data['type'] == 'Announce') {
1273                         if (empty($data['object'])) {
1274                                 return false;
1275                         }
1276                         return self::fetchObject($data['object']);
1277                 }
1278
1279                 logger('Unhandled object type: ' . $data['type'], LOGGER_DEBUG);
1280         }
1281
1282         /**
1283          * @brief
1284          *
1285          * @param $object
1286          *
1287          * @return
1288          */
1289         private static function processObject($object)
1290         {
1291                 if (empty($object['id'])) {
1292                         return false;
1293                 }
1294
1295                 $object_data = [];
1296                 $object_data['object_type'] = $object['type'];
1297                 $object_data['id'] = $object['id'];
1298
1299                 if (!empty($object['inReplyTo'])) {
1300                         $object_data['reply-to-id'] = JsonLD::fetchElement($object, 'inReplyTo', 'id');
1301                 } else {
1302                         $object_data['reply-to-id'] = $object_data['id'];
1303                 }
1304
1305                 $object_data['published'] = defaults($object, 'published', null);
1306                 $object_data['updated'] = defaults($object, 'updated', $object_data['published']);
1307
1308                 if (empty($object_data['published']) && !empty($object_data['updated'])) {
1309                         $object_data['published'] = $object_data['updated'];
1310                 }
1311
1312                 $actor = JsonLD::fetchElement($object, 'attributedTo', 'id');
1313                 if (empty($actor)) {
1314                         $actor = defaults($object, 'actor', null);
1315                 }
1316
1317                 $object_data['diaspora:guid'] = defaults($object, 'diaspora:guid', null);
1318                 $object_data['owner'] = $object_data['author'] = $actor;
1319                 $object_data['context'] = defaults($object, 'context', null);
1320                 $object_data['conversation'] = defaults($object, 'conversation', null);
1321                 $object_data['sensitive'] = defaults($object, 'sensitive', null);
1322                 $object_data['name'] = defaults($object, 'title', null);
1323                 $object_data['name'] = defaults($object, 'name', $object_data['name']);
1324                 $object_data['summary'] = defaults($object, 'summary', null);
1325                 $object_data['content'] = defaults($object, 'content', null);
1326                 $object_data['source'] = defaults($object, 'source', null);
1327                 $object_data['location'] = JsonLD::fetchElement($object, 'location', 'name', 'type', 'Place');
1328                 $object_data['attachments'] = defaults($object, 'attachment', null);
1329                 $object_data['tags'] = defaults($object, 'tag', null);
1330                 $object_data['service'] = JsonLD::fetchElement($object, 'instrument', 'name', 'type', 'Service');
1331                 $object_data['alternate-url'] = JsonLD::fetchElement($object, 'url', 'href');
1332                 $object_data['receiver'] = self::getReceivers($object, $object_data['owner']);
1333
1334                 // Common object data:
1335
1336                 // Unhandled
1337                 // @context, type, actor, signature, mediaType, duration, replies, icon
1338
1339                 // Also missing: (Defined in the standard, but currently unused)
1340                 // audience, preview, endTime, startTime, generator, image
1341
1342                 // Data in Notes:
1343
1344                 // Unhandled
1345                 // contentMap, announcement_count, announcements, context_id, likes, like_count
1346                 // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
1347
1348                 // Data in video:
1349
1350                 // To-Do?
1351                 // category, licence, language, commentsEnabled
1352
1353                 // Unhandled
1354                 // views, waitTranscoding, state, support, subtitleLanguage
1355                 // likes, dislikes, shares, comments
1356
1357                 return $object_data;
1358         }
1359
1360         /**
1361          * @brief Converts mentions from Pleroma into the Friendica format
1362          *
1363          * @param string $body
1364          *
1365          * @return converted body
1366          */
1367         private static function convertMentions($body)
1368         {
1369                 $URLSearchString = "^\[\]";
1370                 $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
1371
1372                 return $body;
1373         }
1374
1375         /**
1376          * @brief Constructs a string with tags for a given tag array
1377          *
1378          * @param array $tags
1379          * @param boolean $sensitive
1380          *
1381          * @return string with tags
1382          */
1383         private static function constructTagList($tags, $sensitive)
1384         {
1385                 if (empty($tags)) {
1386                         return '';
1387                 }
1388
1389                 $tag_text = '';
1390                 foreach ($tags as $tag) {
1391                         if (in_array($tag['type'], ['Mention', 'Hashtag'])) {
1392                                 if (!empty($tag_text)) {
1393                                         $tag_text .= ',';
1394                                 }
1395
1396                                 $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
1397                         }
1398                 }
1399
1400                 /// @todo add nsfw for $sensitive
1401
1402                 return $tag_text;
1403         }
1404
1405         /**
1406          * @brief
1407          *
1408          * @param $attachments
1409          * @param array $item
1410          *
1411          * @return item array
1412          */
1413         private static function constructAttachList($attachments, $item)
1414         {
1415                 if (empty($attachments)) {
1416                         return $item;
1417                 }
1418
1419                 foreach ($attachments as $attach) {
1420                         $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
1421                         if ($filetype == 'image') {
1422                                 $item['body'] .= "\n[img]".$attach['url'].'[/img]';
1423                         } else {
1424                                 if (!empty($item["attach"])) {
1425                                         $item["attach"] .= ',';
1426                                 } else {
1427                                         $item["attach"] = '';
1428                                 }
1429                                 if (!isset($attach['length'])) {
1430                                         $attach['length'] = "0";
1431                                 }
1432                                 $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.defaults($attach, 'name', '').'"[/attach]';
1433                         }
1434                 }
1435
1436                 return $item;
1437         }
1438
1439         /**
1440          * @brief
1441          *
1442          * @param array $activity
1443          * @param $body
1444          */
1445         private static function createItem($activity, $body)
1446         {
1447                 $item = [];
1448                 $item['verb'] = ACTIVITY_POST;
1449                 $item['parent-uri'] = $activity['reply-to-id'];
1450
1451                 if ($activity['reply-to-id'] == $activity['id']) {
1452                         $item['gravity'] = GRAVITY_PARENT;
1453                         $item['object-type'] = ACTIVITY_OBJ_NOTE;
1454                 } else {
1455                         $item['gravity'] = GRAVITY_COMMENT;
1456                         $item['object-type'] = ACTIVITY_OBJ_COMMENT;
1457                 }
1458
1459                 if (($activity['id'] != $activity['reply-to-id']) && !Item::exists(['uri' => $activity['reply-to-id']])) {
1460                         logger('Parent ' . $activity['reply-to-id'] . ' not found. Try to refetch it.');
1461                         self::fetchMissingActivity($activity['reply-to-id'], $activity);
1462                 }
1463
1464                 self::postItem($activity, $item, $body);
1465         }
1466
1467         /**
1468          * @brief
1469          *
1470          * @param array $activity
1471          * @param $body
1472          */
1473         private static function likeItem($activity, $body)
1474         {
1475                 $item = [];
1476                 $item['verb'] = ACTIVITY_LIKE;
1477                 $item['parent-uri'] = $activity['object'];
1478                 $item['gravity'] = GRAVITY_ACTIVITY;
1479                 $item['object-type'] = ACTIVITY_OBJ_NOTE;
1480
1481                 self::postItem($activity, $item, $body);
1482         }
1483
1484         /**
1485          * @brief Delete items
1486          *
1487          * @param array $activity
1488          * @param $body
1489          */
1490         private static function deleteItem($activity)
1491         {
1492                 $owner = Contact::getIdForURL($activity['owner']);
1493                 $object = JsonLD::fetchElement($activity, 'object', 'id');
1494                 logger('Deleting item ' . $object . ' from ' . $owner, LOGGER_DEBUG);
1495                 Item::delete(['uri' => $object, 'owner-id' => $owner]);
1496         }
1497
1498         /**
1499          * @brief
1500          *
1501          * @param array $activity
1502          * @param $body
1503          */
1504         private static function dislikeItem($activity, $body)
1505         {
1506                 $item = [];
1507                 $item['verb'] = ACTIVITY_DISLIKE;
1508                 $item['parent-uri'] = $activity['object'];
1509                 $item['gravity'] = GRAVITY_ACTIVITY;
1510                 $item['object-type'] = ACTIVITY_OBJ_NOTE;
1511
1512                 self::postItem($activity, $item, $body);
1513         }
1514
1515         /**
1516          * @brief
1517          *
1518          * @param array $activity
1519          * @param array $item
1520          * @param $body
1521          */
1522         private static function postItem($activity, $item, $body)
1523         {
1524                 /// @todo What to do with $activity['context']?
1525
1526                 if (($item['gravity'] != GRAVITY_PARENT) && !Item::exists(['uri' => $item['parent-uri']])) {
1527                         logger('Parent ' . $item['parent-uri'] . ' not found, message will be discarded.', LOGGER_DEBUG);
1528                         return;
1529                 }
1530
1531                 $item['network'] = Protocol::ACTIVITYPUB;
1532                 $item['private'] = !in_array(0, $activity['receiver']);
1533                 $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
1534                 $item['owner-id'] = Contact::getIdForURL($activity['owner'], 0, true);
1535                 $item['uri'] = $activity['id'];
1536                 $item['created'] = $activity['published'];
1537                 $item['edited'] = $activity['updated'];
1538                 $item['guid'] = $activity['diaspora:guid'];
1539                 $item['title'] = HTML::toBBCode($activity['name']);
1540                 $item['content-warning'] = HTML::toBBCode($activity['summary']);
1541                 $item['body'] = self::convertMentions(HTML::toBBCode($activity['content']));
1542                 $item['location'] = $activity['location'];
1543                 $item['tag'] = self::constructTagList($activity['tags'], $activity['sensitive']);
1544                 $item['app'] = $activity['service'];
1545                 $item['plink'] = defaults($activity, 'alternate-url', $item['uri']);
1546
1547                 $item = self::constructAttachList($activity['attachments'], $item);
1548
1549                 $source = JsonLD::fetchElement($activity, 'source', 'content', 'mediaType', 'text/bbcode');
1550                 if (!empty($source)) {
1551                         $item['body'] = $source;
1552                 }
1553
1554                 $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
1555                 $item['source'] = $body;
1556                 $item['conversation-href'] = $activity['context'];
1557                 $item['conversation-uri'] = $activity['conversation'];
1558
1559                 foreach ($activity['receiver'] as $receiver) {
1560                         $item['uid'] = $receiver;
1561                         $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
1562
1563                         if (($receiver != 0) && empty($item['contact-id'])) {
1564                                 $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
1565                         }
1566
1567                         $item_id = Item::insert($item);
1568                         logger('Storing for user ' . $item['uid'] . ': ' . $item_id);
1569                 }
1570         }
1571
1572         /**
1573          * @brief
1574          *
1575          * @param $url
1576          * @param $child
1577          */
1578         private static function fetchMissingActivity($url, $child)
1579         {
1580                 if (Config::get('system', 'ostatus_full_threads')) {
1581                         return;
1582                 }
1583
1584                 $object = ActivityPub::fetchContent($url);
1585                 if (empty($object)) {
1586                         logger('Activity ' . $url . ' was not fetchable, aborting.');
1587                         return;
1588                 }
1589
1590                 $activity = [];
1591                 $activity['@context'] = $object['@context'];
1592                 unset($object['@context']);
1593                 $activity['id'] = $object['id'];
1594                 $activity['to'] = defaults($object, 'to', []);
1595                 $activity['cc'] = defaults($object, 'cc', []);
1596                 $activity['actor'] = $child['author'];
1597                 $activity['object'] = $object;
1598                 $activity['published'] = $object['published'];
1599                 $activity['type'] = 'Create';
1600
1601                 self::processActivity($activity);
1602                 logger('Activity ' . $url . ' had been fetched and processed.');
1603         }
1604
1605         /**
1606          * @brief perform a "follow" request
1607          *
1608          * @param array $activity
1609          */
1610         private static function followUser($activity)
1611         {
1612                 $actor = JsonLD::fetchElement($activity, 'object', 'id');
1613                 $uid = User::getIdForURL($actor);
1614                 if (empty($uid)) {
1615                         return;
1616                 }
1617
1618                 $owner = User::getOwnerDataById($uid);
1619
1620                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1621                 if (!empty($cid)) {
1622                         $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1623                 } else {
1624                         $contact = false;
1625                 }
1626
1627                 $item = ['author-id' => Contact::getIdForURL($activity['owner']),
1628                         'author-link' => $activity['owner']];
1629
1630                 Contact::addRelationship($owner, $contact, $item);
1631                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1632                 if (empty($cid)) {
1633                         return;
1634                 }
1635
1636                 $contact = DBA::selectFirst('contact', ['network'], ['id' => $cid]);
1637                 if ($contact['network'] != Protocol::ACTIVITYPUB) {
1638                         Contact::updateFromProbe($cid, Protocol::ACTIVITYPUB);
1639                 }
1640
1641                 DBA::update('contact', ['hub-verify' => $activity['id']], ['id' => $cid]);
1642                 logger('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
1643         }
1644
1645         /**
1646          * @brief Update the given profile
1647          *
1648          * @param array $activity
1649          */
1650         private static function updatePerson($activity)
1651         {
1652                 if (empty($activity['object']['id'])) {
1653                         return;
1654                 }
1655
1656                 logger('Updating profile for ' . $activity['object']['id'], LOGGER_DEBUG);
1657                 APContact::getByURL($activity['object']['id'], true);
1658         }
1659
1660         /**
1661          * @brief Delete the given profile
1662          *
1663          * @param array $activity
1664          */
1665         private static function deletePerson($activity)
1666         {
1667                 if (empty($activity['object']['id']) || empty($activity['object']['actor'])) {
1668                         logger('Empty object id or actor.', LOGGER_DEBUG);
1669                         return;
1670                 }
1671
1672                 if ($activity['object']['id'] != $activity['object']['actor']) {
1673                         logger('Object id does not match actor.', LOGGER_DEBUG);
1674                         return;
1675                 }
1676
1677                 $contacts = DBA::select('contact', ['id'], ['nurl' => normalise_link($activity['object']['id'])]);
1678                 while ($contact = DBA::fetch($contacts)) {
1679                         Contact::remove($contact["id"]);
1680                 }
1681                 DBA::close($contacts);
1682
1683                 logger('Deleted contact ' . $activity['object']['id'], LOGGER_DEBUG);
1684         }
1685
1686         /**
1687          * @brief Accept a follow request
1688          *
1689          * @param array $activity
1690          */
1691         private static function acceptFollowUser($activity)
1692         {
1693                 $actor = JsonLD::fetchElement($activity, 'object', 'actor');
1694                 $uid = User::getIdForURL($actor);
1695                 if (empty($uid)) {
1696                         return;
1697                 }
1698
1699                 $owner = User::getOwnerDataById($uid);
1700
1701                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1702                 if (empty($cid)) {
1703                         logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
1704                         return;
1705                 }
1706
1707                 $fields = ['pending' => false];
1708
1709                 $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
1710                 if ($contact['rel'] == Contact::FOLLOWER) {
1711                         $fields['rel'] = Contact::FRIEND;
1712                 }
1713
1714                 $condition = ['id' => $cid];
1715                 DBA::update('contact', $fields, $condition);
1716                 logger('Accept contact request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
1717         }
1718
1719         /**
1720          * @brief Reject a follow request
1721          *
1722          * @param array $activity
1723          */
1724         private static function rejectFollowUser($activity)
1725         {
1726                 $actor = JsonLD::fetchElement($activity, 'object', 'actor');
1727                 $uid = User::getIdForURL($actor);
1728                 if (empty($uid)) {
1729                         return;
1730                 }
1731
1732                 $owner = User::getOwnerDataById($uid);
1733
1734                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1735                 if (empty($cid)) {
1736                         logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
1737                         return;
1738                 }
1739
1740                 if (DBA::exists('contact', ['id' => $cid, 'rel' => Contact::SHARING, 'pending' => true])) {
1741                         Contact::remove($cid);
1742                         logger('Rejected contact request from contact ' . $cid . ' for user ' . $uid . ' - contact had been removed.', LOGGER_DEBUG);
1743                 } else {
1744                         logger('Rejected contact request from contact ' . $cid . ' for user ' . $uid . '.', LOGGER_DEBUG);
1745                 }
1746         }
1747
1748         /**
1749          * @brief Undo activity like "like" or "dislike"
1750          *
1751          * @param array $activity
1752          */
1753         private static function undoActivity($activity)
1754         {
1755                 $activity_url = JsonLD::fetchElement($activity, 'object', 'id');
1756                 if (empty($activity_url)) {
1757                         return;
1758                 }
1759
1760                 $actor = JsonLD::fetchElement($activity, 'object', 'actor');
1761                 if (empty($actor)) {
1762                         return;
1763                 }
1764
1765                 $author_id = Contact::getIdForURL($actor);
1766                 if (empty($author_id)) {
1767                         return;
1768                 }
1769
1770                 Item::delete(['uri' => $activity_url, 'author-id' => $author_id, 'gravity' => GRAVITY_ACTIVITY]);
1771         }
1772
1773         /**
1774          * @brief Activity to remove a follower
1775          *
1776          * @param array $activity
1777          */
1778         private static function undoFollowUser($activity)
1779         {
1780                 $object = JsonLD::fetchElement($activity, 'object', 'object');
1781                 $uid = User::getIdForURL($object);
1782                 if (empty($uid)) {
1783                         return;
1784                 }
1785
1786                 $owner = User::getOwnerDataById($uid);
1787
1788                 $cid = Contact::getIdForURL($activity['owner'], $uid);
1789                 if (empty($cid)) {
1790                         logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
1791                         return;
1792                 }
1793
1794                 $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
1795                 if (!DBA::isResult($contact)) {
1796                         return;
1797                 }
1798
1799                 Contact::removeFollower($owner, $contact);
1800                 logger('Undo following request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
1801         }
1802 }