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