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