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