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