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