]> git.mxchange.org Git - friendica.git/blobdiff - src/Protocol/ActivityPub.php
Add ActivityPub related fields to the "uri" function
[friendica.git] / src / Protocol / ActivityPub.php
index 4d7657865c226e3c19bfd7921cd28504df0a4363..6c7bbb4745c488f87bec60b9b421dacf6043f9c8 100644 (file)
@@ -4,23 +4,12 @@
  */
 namespace Friendica\Protocol;
 
-use Friendica\Database\DBA;
-use Friendica\Core\System;
-use Friendica\BaseObject;
+use Friendica\Util\JsonLD;
 use Friendica\Util\Network;
-use Friendica\Util\HTTPSignature;
 use Friendica\Core\Protocol;
-use Friendica\Model\Conversation;
-use Friendica\Model\Contact;
-use Friendica\Model\Item;
-use Friendica\Model\Term;
+use Friendica\Model\APContact;
 use Friendica\Model\User;
-use Friendica\Util\DateTimeFormat;
-use Friendica\Util\Crypto;
-use Friendica\Content\Text\BBCode;
-use Friendica\Content\Text\HTML;
-use Friendica\Util\JsonLD;
-use Friendica\Util\LDSignature;
+use Friendica\Util\HTTPSignature;
 
 /**
  * @brief ActivityPub Protocol class
@@ -35,692 +24,108 @@ use Friendica\Util\LDSignature;
  * Digest: https://tools.ietf.org/html/rfc5843
  * https://tools.ietf.org/html/draft-cavage-http-signatures-10#ref-15
  *
- * To-do:
+ * Mastodon implementation of supported activities:
+ * https://github.com/tootsuite/mastodon/blob/master/app/lib/activitypub/activity.rb#L26
  *
- * Receiver:
- * - Activities: Update, Delete (Activities/Notes)
- * - Object Types: Person, Tombstome
+ * Funkwhale:
+ * http://docs-funkwhale-funkwhale-549-music-federation-documentation.preview.funkwhale.audio/federation/index.html
  *
- * Transmitter:
- * - Activities: Announce
- * - Object Tyoes: Person
+ * To-do:
+ * - Polling the outboxes for missing content?
  *
- * General:
- * - Endpoints: Outbox, Follower, Following
- * - General cleanup
- * - Queueing unsucessful deliveries
+ * Missing parts from DFRN:
+ * - Public Forum
+ * - Private Forum
+ * - Relocation
  */
 class ActivityPub
 {
-       const PUBLIC = 'https://www.w3.org/ns/activitystreams#Public';
-
-       public static function isRequest()
-       {
-               return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
-                       stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
-       }
-
+       const PUBLIC_COLLECTION = 'https://www.w3.org/ns/activitystreams#Public';
+       const CONTEXT = ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
+               ['vcard' => 'http://www.w3.org/2006/vcard/ns#',
+               'dfrn' => 'http://purl.org/macgirvin/dfrn/1.0/',
+               'diaspora' => 'https://diasporafoundation.org/ns/',
+               'litepub' => 'http://litepub.social/ns#',
+               'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers',
+               'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
+               'directMessage' => 'litepub:directMessage']];
+       const ACCOUNT_TYPES = ['Person', 'Organization', 'Service', 'Group', 'Application'];
        /**
-        * Return the ActivityPub profile of the given user
+        * Checks if the web request is done for the AP protocol
         *
-        * @param integer $uid User ID
-        * @return array
+        * @return bool is it AP?
         */
-       public static function profile($uid)
-       {
-               $accounttype = ['Person', 'Organization', 'Service', 'Group', 'Application'];
-               $condition = ['uid' => $uid, 'blocked' => false, 'account_expired' => false,
-                       'account_removed' => false, 'verified' => true];
-               $fields = ['guid', 'nickname', 'pubkey', 'account-type', 'page-flags'];
-               $user = DBA::selectFirst('user', $fields, $condition);
-               if (!DBA::isResult($user)) {
-                       return [];
-               }
-
-               $fields = ['locality', 'region', 'country-name'];
-               $profile = DBA::selectFirst('profile', $fields, ['uid' => $uid, 'is-default' => true]);
-               if (!DBA::isResult($profile)) {
-                       return [];
-               }
-
-               $fields = ['name', 'url', 'location', 'about', 'avatar'];
-               $contact = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
-               if (!DBA::isResult($contact)) {
-                       return [];
-               }
-
-               $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
-                       ['vcard' => 'http://www.w3.org/2006/vcard/ns#', 'uuid' => 'http://schema.org/identifier',
-                       'sensitive' => 'as:sensitive', 'manuallyApprovesFollowers' => 'as:manuallyApprovesFollowers']]];
-
-               $data['id'] = $contact['url'];
-               $data['uuid'] = $user['guid'];
-               $data['type'] = $accounttype[$user['account-type']];
-               $data['following'] = System::baseUrl() . '/following/' . $user['nickname'];
-               $data['followers'] = System::baseUrl() . '/followers/' . $user['nickname'];
-               $data['inbox'] = System::baseUrl() . '/inbox/' . $user['nickname'];
-               $data['outbox'] = System::baseUrl() . '/outbox/' . $user['nickname'];
-               $data['preferredUsername'] = $user['nickname'];
-               $data['name'] = $contact['name'];
-               $data['vcard:hasAddress'] = ['@type' => 'vcard:Home', 'vcard:country-name' => $profile['country-name'],
-                       'vcard:region' => $profile['region'], 'vcard:locality' => $profile['locality']];
-               $data['summary'] = $contact['about'];
-               $data['url'] = $contact['url'];
-               $data['manuallyApprovesFollowers'] = in_array($user['page-flags'], [Contact::PAGE_NORMAL, Contact::PAGE_PRVGROUP]);
-               $data['publicKey'] = ['id' => $contact['url'] . '#main-key',
-                       'owner' => $contact['url'],
-                       'publicKeyPem' => $user['pubkey']];
-               $data['endpoints'] = ['sharedInbox' => System::baseUrl() . '/inbox'];
-               $data['icon'] = ['type' => 'Image',
-                       'url' => $contact['avatar']];
-
-               // tags: https://kitty.town/@inmysocks/100656097926961126.json
-               return $data;
-       }
-
-       private static function fetchPermissionBlockFromConversation($item)
-       {
-               if (empty($item['thr-parent'])) {
-                       return [];
-               }
-
-               $condition = ['item-uri' => $item['thr-parent'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
-               $conversation = DBA::selectFirst('conversation', ['source'], $condition);
-               if (!DBA::isResult($conversation)) {
-                       return [];
-               }
-
-               $activity = json_decode($conversation['source'], true);
-
-               $actor = JsonLD::fetchElement($activity, 'actor', 'id');
-               $profile = ActivityPub::fetchprofile($actor);
-
-               $item_profile = ActivityPub::fetchprofile($item['author-link']);
-               $exclude[] = $item['author-link'];
-
-               if ($item['gravity'] == GRAVITY_PARENT) {
-                       $exclude[] = $item['owner-link'];
-               }
-
-               $permissions = [];
-
-               $elements = ['to', 'cc', 'bto', 'bcc'];
-               foreach ($elements as $element) {
-                       if (empty($activity[$element])) {
-                               continue;
-                       }
-                       if (is_string($activity[$element])) {
-                               $activity[$element] = [$activity[$element]];
-                       }
-                       foreach ($activity[$element] as $receiver) {
-                               if ($receiver == $profile['followers'] && !empty($item_profile['followers'])) {
-                                       $receiver = $item_profile['followers'];
-                               }
-                               if (!in_array($receiver, $exclude)) {
-                                       $permissions[$element][] = $receiver;
-                               }
-                       }
-               }
-               return $permissions;
-       }
-
-       public static function createPermissionBlockForItem($item)
-       {
-               $data = ['to' => [], 'cc' => []];
-
-               $data = array_merge($data, self::fetchPermissionBlockFromConversation($item));
-
-               $actor_profile = ActivityPub::fetchprofile($item['author-link']);
-
-               $terms = Term::tagArrayFromItemId($item['id']);
-
-               $contacts[$item['author-link']] = $item['author-link'];
-
-               if (!$item['private']) {
-                       $data['to'][] = self::PUBLIC;
-                       if (!empty($actor_profile['followers'])) {
-                               $data['cc'][] = $actor_profile['followers'];
-                       }
-
-                       foreach ($terms as $term) {
-                               if ($term['type'] != TERM_MENTION) {
-                                       continue;
-                               }
-                               $profile = self::fetchprofile($term['url']);
-                               if (!empty($profile) && empty($contacts[$profile['url']])) {
-                                       $data['cc'][] = $profile['url'];
-                                       $contacts[$profile['url']] = $profile['url'];
-                               }
-                       }
-               } else {
-                       $receiver_list = Item::enumeratePermissions($item);
-
-                       $mentioned = [];
-
-                       foreach ($terms as $term) {
-                               if ($term['type'] != TERM_MENTION) {
-                                       continue;
-                               }
-                               $cid = Contact::getIdForURL($term['url'], $item['uid']);
-                               if (!empty($cid) && in_array($cid, $receiver_list)) {
-                                       $contact = DBA::selectFirst('contact', ['url'], ['id' => $cid, 'network' => Protocol::ACTIVITYPUB]);
-                                       $data['to'][] = $contact['url'];
-                                       $contacts[$contact['url']] = $contact['url'];
-                               }
-                       }
-
-                       foreach ($receiver_list as $receiver) {
-                               $contact = DBA::selectFirst('contact', ['url'], ['id' => $receiver, 'network' => Protocol::ACTIVITYPUB]);
-                               if (empty($contacts[$contact['url']])) {
-                                       $data['cc'][] = $contact['url'];
-                                       $contacts[$contact['url']] = $contact['url'];
-                               }
-                       }
-               }
-
-               $parents = Item::select(['author-link', 'owner-link', 'gravity'], ['parent' => $item['parent']]);
-               while ($parent = Item::fetch($parents)) {
-                       $profile = self::fetchprofile($parent['author-link']);
-                       if (!empty($profile) && empty($contacts[$profile['url']])) {
-                               $data['cc'][] = $profile['url'];
-                               $contacts[$profile['url']] = $profile['url'];
-                       }
-
-                       if ($item['gravity'] != GRAVITY_PARENT) {
-                               continue;
-                       }
-
-                       $profile = self::fetchprofile($parent['owner-link']);
-                       if (!empty($profile) && empty($contacts[$profile['url']])) {
-                               $data['cc'][] = $profile['url'];
-                               $contacts[$profile['url']] = $profile['url'];
-                       }
-               }
-               DBA::close($parents);
-
-               if (empty($data['to'])) {
-                       $data['to'] = $data['cc'];
-                       $data['cc'] = [];
-               }
-
-               return $data;
-       }
-
-       public static function fetchTargetInboxes($item, $uid)
-       {
-               $permissions = self::createPermissionBlockForItem($item);
-               if (empty($permissions)) {
-                       return [];
-               }
-
-               $inboxes = [];
-
-               if ($item['gravity'] == GRAVITY_ACTIVITY) {
-                       $item_profile = ActivityPub::fetchprofile($item['author-link']);
-               } else {
-                       $item_profile = ActivityPub::fetchprofile($item['owner-link']);
-               }
-
-               $elements = ['to', 'cc', 'bto', 'bcc'];
-               foreach ($elements as $element) {
-                       if (empty($permissions[$element])) {
-                               continue;
-                       }
-
-                       foreach ($permissions[$element] as $receiver) {
-                               if ($receiver == $item_profile['followers']) {
-                                       $contacts = DBA::select('contact', ['notify', 'batch'], ['uid' => $uid,
-                                               'rel' => [Contact::FOLLOWER, Contact::FRIEND], 'network' => Protocol::ACTIVITYPUB]);
-                                       while ($contact = DBA::fetch($contacts)) {
-                                               $contact = defaults($contact, 'batch', $contact['notify']);
-                                               $inboxes[$contact] = $contact;
-                                       }
-                                       DBA::close($contacts);
-                               } else {
-                                       $profile = self::fetchprofile($receiver);
-                                       if (!empty($profile)) {
-                                               $target = defaults($profile, 'sharedinbox', $profile['inbox']);
-                                               $inboxes[$target] = $target;
-                                       }
-                               }
-                       }
-               }
-
-               return $inboxes;
-       }
-
-       public static function getTypeOfItem($item)
-       {
-               if ($item['verb'] == ACTIVITY_POST) {
-                       if ($item['created'] == $item['edited']) {
-                               $type = 'Create';
-                       } else {
-                               $type = 'Update';
-                       }
-               } elseif ($item['verb'] == ACTIVITY_LIKE) {
-                       $type = 'Like';
-               } elseif ($item['verb'] == ACTIVITY_DISLIKE) {
-                       $type = 'Dislike';
-               } elseif ($item['verb'] == ACTIVITY_ATTEND) {
-                       $type = 'Accept';
-               } elseif ($item['verb'] == ACTIVITY_ATTENDNO) {
-                       $type = 'Reject';
-               } elseif ($item['verb'] == ACTIVITY_ATTENDMAYBE) {
-                       $type = 'TentativeAccept';
-               } else {
-                       $type = '';
-               }
-
-               return $type;
-       }
-
-       public static function createActivityFromItem($item_id, $object_mode = false)
-       {
-               $item = Item::selectFirst([], ['id' => $item_id]);
-
-               if (!DBA::isResult($item)) {
-                       return false;
-               }
-
-               $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
-               $conversation = DBA::selectFirst('conversation', ['source'], $condition);
-               if (DBA::isResult($conversation)) {
-                       $data = json_decode($conversation['source']);
-                       if (!empty($data)) {
-                               return $data;
-                       }
-               }
-
-               $type = self::getTypeOfItem($item);
-
-               if (!$object_mode) {
-                       $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
-                               ['ostatus' => 'http://ostatus.org#', 'uuid' => 'http://schema.org/identifier',
-                               'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
-                               'atomUri' => 'ostatus:atomUri', 'conversation' => 'ostatus:conversation',
-                               'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']]];
-
-                       if ($item['deleted'] && ($item['gravity'] == GRAVITY_ACTIVITY)) {
-                               $type = 'Undo';
-                       } elseif ($item['deleted']) {
-                               $type = 'Delete';
-                       }
-               } else {
-                       $data = [];
-               }
-
-               $data['id'] = $item['uri'] . '#' . $type;
-               $data['type'] = $type;
-               $data['actor'] = $item['author-link'];
-
-               $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
-
-               if ($item["created"] != $item["edited"]) {
-                       $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
-               }
-
-               $data['context'] = self::createConversationURLFromItem($item);
-
-               $data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
-
-               if (in_array($data['type'], ['Create', 'Update', 'Announce', 'Delete'])) {
-                       $data['object'] = self::CreateNote($item);
-               } elseif ($data['type'] == 'Undo') {
-                       $data['object'] = self::createActivityFromItem($item_id, true);
-               } else {
-                       $data['object'] = $item['thr-parent'];
-               }
-
-               $owner = User::getOwnerDataById($item['uid']);
-
-               if (!$object_mode) {
-                       return LDSignature::sign($data, $owner);
-               } else {
-                       return $data;
-               }
-       }
-
-       public static function createObjectFromItemID($item_id)
-       {
-               $item = Item::selectFirst([], ['id' => $item_id]);
-
-               if (!DBA::isResult($item)) {
-                       return false;
-               }
-
-               $data = ['@context' => ['https://www.w3.org/ns/activitystreams', 'https://w3id.org/security/v1',
-                       ['ostatus' => 'http://ostatus.org#', 'uuid' => 'http://schema.org/identifier',
-                       'sensitive' => 'as:sensitive', 'Hashtag' => 'as:Hashtag',
-                       'atomUri' => 'ostatus:atomUri', 'conversation' => 'ostatus:conversation',
-                       'inReplyToAtomUri' => 'ostatus:inReplyToAtomUri']]];
-
-               $data = array_merge($data, self::CreateNote($item));
-
-
-               return $data;
-       }
-
-       private static function createTagList($item)
-       {
-               $tags = [];
-
-               $terms = Term::tagArrayFromItemId($item['id']);
-               foreach ($terms as $term) {
-                       if ($term['type'] == TERM_MENTION) {
-                               $contact = Contact::getDetailsByURL($term['url']);
-                               if (!empty($contact['addr'])) {
-                                       $mention = '@' . $contact['addr'];
-                               } else {
-                                       $mention = '@' . $term['url'];
-                               }
-
-                               $tags[] = ['type' => 'Mention', 'href' => $term['url'], 'name' => $mention];
-                       }
-               }
-               return $tags;
-       }
-
-       private static function createConversationURLFromItem($item)
-       {
-               $conversation = DBA::selectFirst('conversation', ['conversation-uri'], ['item-uri' => $item['parent-uri']]);
-               if (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
-                       $conversation_uri = $conversation['conversation-uri'];
-               } else {
-                       $conversation_uri = $item['parent-uri'];
-               }
-               return $conversation_uri;
-       }
-
-       private static function CreateNote($item)
-       {
-               if (!empty($item['title'])) {
-                       $type = 'Article';
-               } else {
-                       $type = 'Note';
-               }
-
-               if ($item['deleted']) {
-                       $type = 'Tombstone';
-               }
-
-               $data = [];
-               $data['id'] = $item['uri'];
-               $data['type'] = $type;
-
-               if ($item['deleted']) {
-                       return $data;
-               }
-
-               $data['summary'] = null; // Ignore by now
-
-               if ($item['uri'] != $item['thr-parent']) {
-                       $data['inReplyTo'] = $item['thr-parent'];
-               } else {
-                       $data['inReplyTo'] = null;
-               }
-
-               $data['uuid'] = $item['guid'];
-               $data['published'] = DateTimeFormat::utc($item["created"]."+00:00", DateTimeFormat::ATOM);
-
-               if ($item["created"] != $item["edited"]) {
-                       $data['updated'] = DateTimeFormat::utc($item["edited"]."+00:00", DateTimeFormat::ATOM);
-               }
-
-               $data['url'] = $item['plink'];
-               $data['attributedTo'] = $item['author-link'];
-               $data['actor'] = $item['author-link'];
-               $data['sensitive'] = false; // - Query NSFW
-               $data['conversation'] = $data['context'] = self::createConversationURLFromItem($item);
-
-               if (!empty($item['title'])) {
-                       $data['name'] = BBCode::convert($item['title'], false, 7);
-               }
-
-               $data['content'] = BBCode::convert($item['body'], false, 7);
-               $data['source'] = ['content' => $item['body'], 'mediaType' => "text/bbcode"];
-               $data['attachment'] = []; // @ToDo
-               $data['tag'] = self::createTagList($item);
-               $data = array_merge($data, ActivityPub::createPermissionBlockForItem($item));
-
-               //$data['emoji'] = []; // Ignore by now
-               return $data;
-       }
-
-       public static function transmitActivity($activity, $target, $uid)
-       {
-               $profile = self::fetchprofile($target);
-
-               $owner = User::getOwnerDataById($uid);
-
-               $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
-                       'id' => System::baseUrl() . '/activity/' . System::createGUID(),
-                       'type' => $activity,
-                       'actor' => $owner['url'],
-                       'object' => $profile['url'],
-                       'to' => $profile['url']];
-
-               logger('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid, LOGGER_DEBUG);
-
-               $signed = LDSignature::sign($data, $owner);
-               return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
-       }
-
-       public static function transmitContactAccept($target, $id, $uid)
-       {
-               $profile = self::fetchprofile($target);
-
-               $owner = User::getOwnerDataById($uid);
-               $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
-                       'id' => System::baseUrl() . '/activity/' . System::createGUID(),
-                       'type' => 'Accept',
-                       'actor' => $owner['url'],
-                       'object' => ['id' => $id, 'type' => 'Follow',
-                               'actor' => $profile['url'],
-                               'object' => $owner['url']],
-                       'to' => $profile['url']];
-
-               logger('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
-
-               $signed = LDSignature::sign($data, $owner);
-               return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
-       }
-
-       public static function transmitContactReject($target, $id, $uid)
-       {
-               $profile = self::fetchprofile($target);
-
-               $owner = User::getOwnerDataById($uid);
-               $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
-                       'id' => System::baseUrl() . '/activity/' . System::createGUID(),
-                       'type' => 'Reject',
-                       'actor' => $owner['url'],
-                       'object' => ['id' => $id, 'type' => 'Follow',
-                               'actor' => $profile['url'],
-                               'object' => $owner['url']],
-                       'to' => $profile['url']];
-
-               logger('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
-
-               $signed = LDSignature::sign($data, $owner);
-               return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
-       }
-
-       public static function transmitContactUndo($target, $uid)
+       public static function isRequest()
        {
-               $profile = self::fetchprofile($target);
-
-               $id = System::baseUrl() . '/activity/' . System::createGUID();
-
-               $owner = User::getOwnerDataById($uid);
-               $data = ['@context' => 'https://www.w3.org/ns/activitystreams',
-                       'id' => $id,
-                       'type' => 'Undo',
-                       'actor' => $owner['url'],
-                       'object' => ['id' => $id, 'type' => 'Follow',
-                               'actor' => $owner['url'],
-                               'object' => $profile['url']],
-                       'to' => $profile['url']];
-
-               logger('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id, LOGGER_DEBUG);
-
-               $signed = LDSignature::sign($data, $owner);
-               return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
+               return stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/activity+json') ||
+                       stristr(defaults($_SERVER, 'HTTP_ACCEPT', ''), 'application/ld+json');
        }
 
        /**
         * Fetches ActivityPub content from the given url
         *
-        * @param string $url content url
+        * @param string  $url content url
+        * @param integer $uid User ID for the signature
         * @return array
+        * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       public static function fetchContent($url)
-       {
-               $ret = Network::curl($url, false, $redirects, ['accept_content' => 'application/activity+json, application/ld+json']);
-               if (!$ret['success'] || empty($ret['body'])) {
-                       return;
-               }
-
-               return json_decode($ret['body'], true);
-       }
-
-       /**
-        * Resolves the profile url from the address by using webfinger
-        *
-        * @param string $addr profile address (user@domain.tld)
-        * @return string url
-        */
-       private static function addrToUrl($addr)
+       public static function fetchContent($url, $uid = 0)
        {
-               $addr_parts = explode('@', $addr);
-               if (count($addr_parts) != 2) {
-                       return false;
+               if (!empty($uid)) {
+                       return HTTPSignature::fetch($url, $uid);
                }
 
-               $webfinger = 'https://' . $addr_parts[1] . '/.well-known/webfinger?resource=acct:' . urlencode($addr);
-
-               $ret = Network::curl($webfinger, false, $redirects, ['accept_content' => 'application/jrd+json,application/json']);
-               if (!$ret['success'] || empty($ret['body'])) {
+               $curlResult = Network::curl($url, false, ['accept_content' => 'application/activity+json, application/ld+json']);
+               if (!$curlResult->isSuccess() || empty($curlResult->getBody())) {
                        return false;
                }
 
-               $data = json_decode($ret['body'], true);
+               $content = json_decode($curlResult->getBody(), true);
 
-               if (empty($data['links'])) {
+               if (empty($content) || !is_array($content)) {
                        return false;
                }
 
-               foreach ($data['links'] as $link) {
-                       if (empty($link['href']) || empty($link['rel']) || empty($link['type'])) {
-                               continue;
-                       }
-
-                       if (($link['rel'] == 'self') && ($link['type'] == 'application/activity+json')) {
-                               return $link['href'];
-                       }
-               }
-
-               return false;
+               return $content;
        }
 
-       public static function fetchprofile($url, $update = false)
+       private static function getAccountType($apcontact)
        {
-               if (empty($url)) {
-                       return false;
-               }
-
-               if (!$update) {
-                       $apcontact = DBA::selectFirst('apcontact', [], ['url' => $url]);
-                       if (DBA::isResult($apcontact)) {
-                               return $apcontact;
-                       }
-
-                       $apcontact = DBA::selectFirst('apcontact', [], ['alias' => $url]);
-                       if (DBA::isResult($apcontact)) {
-                               return $apcontact;
-                       }
-
-                       $apcontact = DBA::selectFirst('apcontact', [], ['addr' => $url]);
-                       if (DBA::isResult($apcontact)) {
-                               return $apcontact;
-                       }
-               }
-
-               if (empty(parse_url($url, PHP_URL_SCHEME))) {
-                       $url = self::addrToUrl($url);
-                       if (empty($url)) {
-                               return false;
-                       }
-               }
-
-               $data = self::fetchContent($url);
-
-               if (empty($data) || empty($data['id']) || empty($data['inbox'])) {
-                       return false;
-               }
+               $accounttype = -1;
 
-               $apcontact = [];
-               $apcontact['url'] = $data['id'];
-               $apcontact['uuid'] = defaults($data, 'uuid', null);
-               $apcontact['type'] = defaults($data, 'type', null);
-               $apcontact['following'] = defaults($data, 'following', null);
-               $apcontact['followers'] = defaults($data, 'followers', null);
-               $apcontact['inbox'] = defaults($data, 'inbox', null);
-               $apcontact['outbox'] = defaults($data, 'outbox', null);
-               $apcontact['sharedinbox'] = JsonLD::fetchElement($data, 'endpoints', 'sharedInbox');
-               $apcontact['nick'] = defaults($data, 'preferredUsername', null);
-               $apcontact['name'] = defaults($data, 'name', $apcontact['nick']);
-               $apcontact['about'] = defaults($data, 'summary', '');
-               $apcontact['photo'] = JsonLD::fetchElement($data, 'icon', 'url');
-               $apcontact['alias'] = JsonLD::fetchElement($data, 'url', 'href');
-
-               $parts = parse_url($apcontact['url']);
-               unset($parts['scheme']);
-               unset($parts['path']);
-               $apcontact['addr'] = $apcontact['nick'] . '@' . str_replace('//', '', Network::unparseURL($parts));
-
-               $apcontact['pubkey'] = trim(JsonLD::fetchElement($data, 'publicKey', 'publicKeyPem'));
-
-               // To-Do
-               // manuallyApprovesFollowers
-
-               // Unhandled
-               // @context, tag, attachment, image, nomadicLocations, signature, following, followers, featured, movedTo, liked
-
-               // Unhandled from Misskey
-               // sharedInbox, isCat
-
-               // Unhandled from Kroeg
-               // kroeg:blocks, updated
-
-               // Check if the address is resolvable
-               if (self::addrToUrl($apcontact['addr']) == $apcontact['url']) {
-                       $parts = parse_url($apcontact['url']);
-                       unset($parts['path']);
-                       $apcontact['baseurl'] = Network::unparseURL($parts);
-               } else {
-                       $apcontact['addr'] = null;
-               }
-
-               if ($apcontact['url'] == $apcontact['alias']) {
-                       $apcontact['alias'] = null;
+               switch($apcontact['type']) {
+                       case 'Person':
+                               $accounttype = User::ACCOUNT_TYPE_PERSON;
+                               break;
+                       case 'Organization':
+                               $accounttype = User::ACCOUNT_TYPE_ORGANISATION;
+                               break;
+                       case 'Service':
+                               $accounttype = User::ACCOUNT_TYPE_NEWS;
+                               break;
+                       case 'Group':
+                               $accounttype = User::ACCOUNT_TYPE_COMMUNITY;
+                               break;
+                       case 'Application':
+                               $accounttype = User::ACCOUNT_TYPE_RELAY;
+                               break;
                }
 
-               $apcontact['updated'] = DateTimeFormat::utcNow();
-
-               DBA::update('apcontact', $apcontact, ['url' => $url], true);
-
-               return $apcontact;
+               return $accounttype;
        }
 
        /**
         * Fetches a profile from the given url into an array that is compatible to Probe::uri
         *
-        * @param string $url profile url
+        * @param string  $url    profile url
+        * @param boolean $update Update the profile
         * @return array
+        * @throws \Friendica\Network\HTTPException\InternalServerErrorException
+        * @throws \ImagickException
         */
-       public static function probeProfile($url)
+       public static function probeProfile($url, $update = true)
        {
-               $apcontact = self::fetchprofile($url, true);
+               $apcontact = APContact::getByURL($url, $update);
                if (empty($apcontact)) {
                        return false;
                }
@@ -732,8 +137,14 @@ class ActivityPub
                $profile['url'] = $apcontact['url'];
                $profile['addr'] = $apcontact['addr'];
                $profile['alias'] = $apcontact['alias'];
+               $profile['following'] = $apcontact['following'];
+               $profile['followers'] = $apcontact['followers'];
+               $profile['inbox'] = $apcontact['inbox'];
+               $profile['outbox'] = $apcontact['outbox'];
+               $profile['sharedinbox'] = $apcontact['sharedinbox'];
                $profile['photo'] = $apcontact['photo'];
-               // $profile['community']
+               $profile['account-type'] = self::getAccountType($apcontact);
+               $profile['community'] = ($profile['account-type'] == User::ACCOUNT_TYPE_COMMUNITY);
                // $profile['keywords']
                // $profile['location']
                $profile['about'] = $apcontact['about'];
@@ -753,52 +164,13 @@ class ActivityPub
                return $profile;
        }
 
-       public static function processInbox($body, $header, $uid)
-       {
-               $http_signer = HTTPSignature::getSigner($body, $header);
-               if (empty($http_signer)) {
-                       logger('Invalid HTTP signature, message will be discarded.', LOGGER_DEBUG);
-                       return;
-               } else {
-                       logger('HTTP signature is signed by ' . $http_signer, LOGGER_DEBUG);
-               }
-
-               $activity = json_decode($body, true);
-
-               $actor = JsonLD::fetchElement($activity, 'actor', 'id');
-               logger('Message for user ' . $uid . ' is from actor ' . $actor, LOGGER_DEBUG);
-
-               if (empty($activity)) {
-                       logger('Invalid body.', LOGGER_DEBUG);
-                       return;
-               }
-
-               if (LDSignature::isSigned($activity)) {
-                       $ld_signer = LDSignature::getSigner($activity);
-                       if (!empty($ld_signer && ($actor == $http_signer))) {
-                               logger('The HTTP and the JSON-LD signature belong to ' . $ld_signer, LOGGER_DEBUG);
-                               $trust_source = true;
-                       } elseif (!empty($ld_signer)) {
-                               logger('JSON-LD signature is signed by ' . $ld_signer, LOGGER_DEBUG);
-                               $trust_source = true;
-                       } elseif ($actor == $http_signer) {
-                               logger('Bad JSON-LD signature, but HTTP signer fits the actor.', LOGGER_DEBUG);
-                               $trust_source = true;
-                       } else {
-                               logger('Invalid JSON-LD signature and the HTTP signer is different.', LOGGER_DEBUG);
-                               $trust_source = false;
-                       }
-               } elseif ($actor == $http_signer) {
-                       logger('Trusting post without JSON-LD signature, The actor fits the HTTP signer.', LOGGER_DEBUG);
-                       $trust_source = true;
-               } else {
-                       logger('No JSON-LD signature, different actor.', LOGGER_DEBUG);
-                       $trust_source = false;
-               }
-
-               self::processActivity($activity, $body, $uid, $trust_source);
-       }
-
+       /**
+        * Fetches activities from the outbox of a given profile and processes it
+        *
+        * @param string  $url
+        * @param integer $uid User ID
+        * @throws \Friendica\Network\HTTPException\InternalServerErrorException
+        */
        public static function fetchOutbox($url, $uid)
        {
                $data = self::fetchContent($url);
@@ -818,655 +190,8 @@ class ActivityPub
                }
 
                foreach ($items as $activity) {
-                       self::processActivity($activity, '', $uid, true);
-               }
-       }
-
-       private static function prepareObjectData($activity, $uid, $trust_source)
-       {
-               $actor = JsonLD::fetchElement($activity, 'actor', 'id');
-               if (empty($actor)) {
-                       logger('Empty actor', LOGGER_DEBUG);
-                       return [];
-               }
-
-               // Fetch all receivers from to, cc, bto and bcc
-               $receivers = self::getReceivers($activity, $actor);
-
-               // When it is a delivery to a personal inbox we add that user to the receivers
-               if (!empty($uid)) {
-                       $owner = User::getOwnerDataById($uid);
-                       $additional = ['uid:' . $uid => $uid];
-                       $receivers = array_merge($receivers, $additional);
-               }
-
-               logger('Receivers: ' . json_encode($receivers), LOGGER_DEBUG);
-
-               if (is_string($activity['object'])) {
-                       $object_url = $activity['object'];
-               } elseif (!empty($activity['object']['id'])) {
-                       $object_url = $activity['object']['id'];
-               } else {
-                       logger('No object found', LOGGER_DEBUG);
-                       return [];
-               }
-
-               // Fetch the content only on activities where this matters
-               if (in_array($activity['type'], ['Create', 'Update', 'Announce'])) {
-                       $object_data = self::fetchObject($object_url, $activity['object'], $trust_source);
-                       if (empty($object_data)) {
-                               logger("Object data couldn't be processed", LOGGER_DEBUG);
-                               return [];
-                       }
-               } elseif ($activity['type'] == 'Accept') {
-                       $object_data = [];
-                       $object_data['object_type'] = JsonLD::fetchElement($activity, 'object', 'type');
-                       $object_data['object'] = JsonLD::fetchElement($activity, 'object', 'actor');
-               } elseif ($activity['type'] == 'Undo') {
-                       $object_data = [];
-                       $object_data['object_type'] = JsonLD::fetchElement($activity, 'object', 'type');
-                       $object_data['object'] = JsonLD::fetchElement($activity, 'object', 'object');
-               } elseif (in_array($activity['type'], ['Like', 'Dislike'])) {
-                       // Create a mostly empty array out of the activity data (instead of the object).
-                       // This way we later don't have to check for the existence of ech individual array element.
-                       $object_data = self::processCommonData($activity);
-                       $object_data['name'] = $activity['type'];
-                       $object_data['author'] = $activity['actor'];
-                       $object_data['object'] = $object_url;
-               } elseif ($activity['type'] == 'Follow') {
-                       $object_data['id'] = $activity['id'];
-                       $object_data['object'] = $object_url;
-               } else {
-                       $object_data = [];
-               }
-
-               $object_data = self::addActivityFields($object_data, $activity);
-
-               $object_data['type'] = $activity['type'];
-               $object_data['owner'] = $actor;
-               $object_data['receiver'] = array_merge(defaults($object_data, 'receiver', []), $receivers);
-
-               return $object_data;
-       }
-
-       private static function processActivity($activity, $body = '', $uid = null, $trust_source = false)
-       {
-               if (empty($activity['type'])) {
-                       logger('Empty type', LOGGER_DEBUG);
-                       return;
-               }
-
-               if (empty($activity['object'])) {
-                       logger('Empty object', LOGGER_DEBUG);
-                       return;
-               }
-
-               if (empty($activity['actor'])) {
-                       logger('Empty actor', LOGGER_DEBUG);
-                       return;
-
-               }
-
-               // Non standard
-               // title, atomUri, context_id, statusnetConversationId
-
-               // To-Do?
-               // context, location, signature;
-
-               logger('Processing activity: ' . $activity['type'], LOGGER_DEBUG);
-
-               $object_data = self::prepareObjectData($activity, $uid, $trust_source);
-               if (empty($object_data)) {
-                       logger('No object data found', LOGGER_DEBUG);
-                       return;
-               }
-
-               switch ($activity['type']) {
-                       case 'Create':
-                       case 'Announce':
-                               self::createItem($object_data, $body);
-                               break;
-
-                       case 'Like':
-                               self::likeItem($object_data, $body);
-                               break;
-
-                       case 'Dislike':
-                               self::dislikeItem($object_data, $body);
-                               break;
-
-                       case 'Update':
-                               break;
-
-                       case 'Delete':
-                               break;
-
-                       case 'Follow':
-                               self::followUser($object_data);
-                               break;
-
-                       case 'Accept':
-                               if ($object_data['object_type'] == 'Follow') {
-                                       self::acceptFollowUser($object_data);
-                               }
-                               break;
-
-                       case 'Undo':
-                               if ($object_data['object_type'] == 'Follow') {
-                                       self::undoFollowUser($object_data);
-                               }
-                               break;
-
-                       default:
-                               logger('Unknown activity: ' . $activity['type'], LOGGER_DEBUG);
-                               break;
-               }
-       }
-
-       private static function getReceivers($activity, $actor)
-       {
-               $receivers = [];
-
-               // When it is an answer, we inherite the receivers from the parent
-               $replyto = JsonLD::fetchElement($activity, 'inReplyTo', 'id');
-               if (!empty($replyto)) {
-                       $parents = Item::select(['uid'], ['uri' => $replyto]);
-                       while ($parent = Item::fetch($parents)) {
-                               $receivers['uid:' . $parent['uid']] = $parent['uid'];
-                       }
-               }
-
-               if (!empty($actor)) {
-                       $profile = self::fetchprofile($actor);
-                       $followers = defaults($profile, 'followers', '');
-
-                       logger('Actor: ' . $actor . ' - Followers: ' . $followers, LOGGER_DEBUG);
-               } else {
-                       logger('Empty actor', LOGGER_DEBUG);
-                       $followers = '';
-               }
-
-               $elements = ['to', 'cc', 'bto', 'bcc'];
-               foreach ($elements as $element) {
-                       if (empty($activity[$element])) {
-                               continue;
-                       }
-
-                       // The receiver can be an arror or a string
-                       if (is_string($activity[$element])) {
-                               $activity[$element] = [$activity[$element]];
-                       }
-
-                       foreach ($activity[$element] as $receiver) {
-                               if ($receiver == self::PUBLIC) {
-                                       $receivers['uid:0'] = 0;
-                               }
-
-                               if (($receiver == self::PUBLIC) && !empty($actor)) {
-                                       // This will most likely catch all OStatus connections to Mastodon
-                                       $condition = ['alias' => [$actor, normalise_link($actor)], 'rel' => [Contact::SHARING, Contact::FRIEND]];
-                                       $contacts = DBA::select('contact', ['uid'], $condition);
-                                       while ($contact = DBA::fetch($contacts)) {
-                                               if ($contact['uid'] != 0) {
-                                                       $receivers['uid:' . $contact['uid']] = $contact['uid'];
-                                               }
-                                       }
-                                       DBA::close($contacts);
-                               }
-
-                               if (in_array($receiver, [$followers, self::PUBLIC]) && !empty($actor)) {
-                                       $condition = ['nurl' => normalise_link($actor), 'rel' => [Contact::SHARING, Contact::FRIEND],
-                                               'network' => Protocol::ACTIVITYPUB];
-                                       $contacts = DBA::select('contact', ['uid'], $condition);
-                                       while ($contact = DBA::fetch($contacts)) {
-                                               if ($contact['uid'] != 0) {
-                                                       $receivers['uid:' . $contact['uid']] = $contact['uid'];
-                                               }
-                                       }
-                                       DBA::close($contacts);
-                                       continue;
-                               }
-
-                               $condition = ['self' => true, 'nurl' => normalise_link($receiver)];
-                               $contact = DBA::selectFirst('contact', ['uid'], $condition);
-                               if (!DBA::isResult($contact)) {
-                                       continue;
-                               }
-                               $receivers['uid:' . $contact['uid']] = $contact['uid'];
-                       }
-               }
-               return $receivers;
-       }
-
-       private static function addActivityFields($object_data, $activity)
-       {
-               if (!empty($activity['published']) && empty($object_data['published'])) {
-                       $object_data['published'] = $activity['published'];
-               }
-
-               if (!empty($activity['updated']) && empty($object_data['updated'])) {
-                       $object_data['updated'] = $activity['updated'];
-               }
-
-               if (!empty($activity['inReplyTo']) && empty($object_data['parent-uri'])) {
-                       $object_data['parent-uri'] = JsonLD::fetchElement($activity, 'inReplyTo', 'id');
-               }
-
-               if (!empty($activity['instrument'])) {
-                       $object_data['service'] = JsonLD::fetchElement($activity, 'instrument', 'name', 'type', 'Service');
-               }
-               return $object_data;
-       }
-
-       private static function fetchObject($object_url, $object = [], $trust_source = false)
-       {
-               if (!$trust_source || is_string($object)) {
-                       $data = self::fetchContent($object_url);
-                       if (empty($data)) {
-                               logger('Empty content for ' . $object_url . ', check if content is available locally.', LOGGER_DEBUG);
-                               $data = $object_url;
-                       } else {
-                               logger('Fetched content for ' . $object_url, LOGGER_DEBUG);
-                       }
-               } else {
-                       logger('Using original object for url ' . $object_url, LOGGER_DEBUG);
-                       $data = $object;
-               }
-
-               if (is_string($data)) {
-                       $item = Item::selectFirst([], ['uri' => $data]);
-                       if (!DBA::isResult($item)) {
-                               logger('Object with url ' . $data . ' was not found locally.', LOGGER_DEBUG);
-                               return false;
-                       }
-                       logger('Using already stored item for url ' . $object_url, LOGGER_DEBUG);
-                       $data = self::CreateNote($item);
-               }
-
-               if (empty($data['type'])) {
-                       logger('Empty type', LOGGER_DEBUG);
-                       return false;
-               } else {
-                       $type = $data['type'];
-                       logger('Type ' . $type, LOGGER_DEBUG);
-               }
-
-               if (in_array($type, ['Note', 'Article', 'Video'])) {
-                       $common = self::processCommonData($data);
-               }
-
-               switch ($type) {
-                       case 'Note':
-                               return array_merge($common, self::processNote($data));
-                       case 'Article':
-                               return array_merge($common, self::processArticle($data));
-                       case 'Video':
-                               return array_merge($common, self::processVideo($data));
-
-                       case 'Announce':
-                               if (empty($data['object'])) {
-                                       return false;
-                               }
-                               return self::fetchObject($data['object']);
-
-                       case 'Person':
-                       case 'Tombstone':
-                               break;
-
-                       default:
-                               logger('Unknown object type: ' . $data['type'], LOGGER_DEBUG);
-                               break;
-               }
-       }
-
-       private static function processCommonData(&$object)
-       {
-               if (empty($object['id'])) {
-                       return false;
+                       $ldactivity = JsonLD::compact($activity);
+                       ActivityPub\Receiver::processActivity($ldactivity, '', $uid, true);
                }
-
-               $object_data = [];
-               $object_data['type'] = $object['type'];
-               $object_data['uri'] = $object['id'];
-
-               if (!empty($object['inReplyTo'])) {
-                       $object_data['reply-to-uri'] = JsonLD::fetchElement($object, 'inReplyTo', 'id');
-               } else {
-                       $object_data['reply-to-uri'] = $object_data['uri'];
-               }
-
-               $object_data['published'] = defaults($object, 'published', null);
-               $object_data['updated'] = defaults($object, 'updated', $object_data['published']);
-
-               if (empty($object_data['published']) && !empty($object_data['updated'])) {
-                       $object_data['published'] = $object_data['updated'];
-               }
-
-               $object_data['uuid'] = defaults($object, 'uuid', null);
-               $object_data['owner'] = $object_data['author'] = JsonLD::fetchElement($object, 'attributedTo', 'id');
-               $object_data['context'] = defaults($object, 'context', null);
-               $object_data['conversation'] = defaults($object, 'conversation', null);
-               $object_data['sensitive'] = defaults($object, 'sensitive', null);
-               $object_data['name'] = defaults($object, 'title', null);
-               $object_data['name'] = defaults($object, 'name', $object_data['name']);
-               $object_data['summary'] = defaults($object, 'summary', null);
-               $object_data['content'] = defaults($object, 'content', null);
-               $object_data['source'] = defaults($object, 'source', null);
-               $object_data['location'] = JsonLD::fetchElement($object, 'location', 'name', 'type', 'Place');
-               $object_data['attachments'] = defaults($object, 'attachment', null);
-               $object_data['tags'] = defaults($object, 'tag', null);
-               $object_data['service'] = JsonLD::fetchElement($object, 'instrument', 'name', 'type', 'Service');
-               $object_data['alternate-url'] = JsonLD::fetchElement($object, 'url', 'href');
-               $object_data['receiver'] = self::getReceivers($object, $object_data['owner']);
-
-               // Unhandled
-               // @context, type, actor, signature, mediaType, duration, replies, icon
-
-               // Also missing: (Defined in the standard, but currently unused)
-               // audience, preview, endTime, startTime, generator, image
-
-               return $object_data;
-       }
-
-       private static function processNote($object)
-       {
-               $object_data = [];
-
-               // To-Do?
-               // emoji, atomUri, inReplyToAtomUri
-
-               // Unhandled
-               // contentMap, announcement_count, announcements, context_id, likes, like_count
-               // inReplyToStatusId, shares, quoteUrl, statusnetConversationId
-
-               return $object_data;
-       }
-
-       private static function processArticle($object)
-       {
-               $object_data = [];
-
-               return $object_data;
-       }
-
-       private static function processVideo($object)
-       {
-               $object_data = [];
-
-               // To-Do?
-               // category, licence, language, commentsEnabled
-
-               // Unhandled
-               // views, waitTranscoding, state, support, subtitleLanguage
-               // likes, dislikes, shares, comments
-
-               return $object_data;
-       }
-
-       private static function convertMentions($body)
-       {
-               $URLSearchString = "^\[\]";
-               $body = preg_replace("/\[url\=([$URLSearchString]*)\]([#@!])(.*?)\[\/url\]/ism", '$2[url=$1]$3[/url]', $body);
-
-               return $body;
-       }
-
-       private static function constructTagList($tags, $sensitive)
-       {
-               if (empty($tags)) {
-                       return '';
-               }
-
-               $tag_text = '';
-               foreach ($tags as $tag) {
-                       if (in_array($tag['type'], ['Mention', 'Hashtag'])) {
-                               if (!empty($tag_text)) {
-                                       $tag_text .= ',';
-                               }
-
-                               if (empty($tag['href'])) {
-                                       //$tag['href']
-                                       logger('Blubb!');
-                               }
-
-                               $tag_text .= substr($tag['name'], 0, 1) . '[url=' . $tag['href'] . ']' . substr($tag['name'], 1) . '[/url]';
-                       }
-               }
-
-               /// @todo add nsfw for $sensitive
-
-               return $tag_text;
-       }
-
-       private static function constructAttachList($attachments, $item)
-       {
-               if (empty($attachments)) {
-                       return $item;
-               }
-
-               foreach ($attachments as $attach) {
-                       $filetype = strtolower(substr($attach['mediaType'], 0, strpos($attach['mediaType'], '/')));
-                       if ($filetype == 'image') {
-                               $item['body'] .= "\n[img]".$attach['url'].'[/img]';
-                       } else {
-                               if (!empty($item["attach"])) {
-                                       $item["attach"] .= ',';
-                               } else {
-                                       $item["attach"] = '';
-                               }
-                               if (!isset($attach['length'])) {
-                                       $attach['length'] = "0";
-                               }
-                               $item["attach"] .= '[attach]href="'.$attach['url'].'" length="'.$attach['length'].'" type="'.$attach['mediaType'].'" title="'.defaults($attach, 'name', '').'"[/attach]';
-                       }
-               }
-
-               return $item;
-       }
-
-       private static function createItem($activity, $body)
-       {
-               $item = [];
-               $item['verb'] = ACTIVITY_POST;
-               $item['parent-uri'] = $activity['reply-to-uri'];
-
-               if ($activity['reply-to-uri'] == $activity['uri']) {
-                       $item['gravity'] = GRAVITY_PARENT;
-                       $item['object-type'] = ACTIVITY_OBJ_NOTE;
-               } else {
-                       $item['gravity'] = GRAVITY_COMMENT;
-                       $item['object-type'] = ACTIVITY_OBJ_COMMENT;
-               }
-
-               if (($activity['uri'] != $activity['reply-to-uri']) && !Item::exists(['uri' => $activity['reply-to-uri']])) {
-                       logger('Parent ' . $activity['reply-to-uri'] . ' not found. Try to refetch it.');
-                       self::fetchMissingActivity($activity['reply-to-uri'], $activity);
-               }
-
-               self::postItem($activity, $item, $body);
-       }
-
-       private static function likeItem($activity, $body)
-       {
-               $item = [];
-               $item['verb'] = ACTIVITY_LIKE;
-               $item['parent-uri'] = $activity['object'];
-               $item['gravity'] = GRAVITY_ACTIVITY;
-               $item['object-type'] = ACTIVITY_OBJ_NOTE;
-
-               self::postItem($activity, $item, $body);
-       }
-
-       private static function dislikeItem($activity, $body)
-       {
-               $item = [];
-               $item['verb'] = ACTIVITY_DISLIKE;
-               $item['parent-uri'] = $activity['object'];
-               $item['gravity'] = GRAVITY_ACTIVITY;
-               $item['object-type'] = ACTIVITY_OBJ_NOTE;
-
-               self::postItem($activity, $item, $body);
-       }
-
-       private static function postItem($activity, $item, $body)
-       {
-               /// @todo What to do with $activity['context']?
-
-               $item['network'] = Protocol::ACTIVITYPUB;
-               $item['private'] = !in_array(0, $activity['receiver']);
-               $item['author-id'] = Contact::getIdForURL($activity['author'], 0, true);
-               $item['owner-id'] = Contact::getIdForURL($activity['owner'], 0, true);
-               $item['uri'] = $activity['uri'];
-               $item['created'] = $activity['published'];
-               $item['edited'] = $activity['updated'];
-               $item['guid'] = $activity['uuid'];
-               $item['title'] = HTML::toBBCode($activity['name']);
-               $item['content-warning'] = HTML::toBBCode($activity['summary']);
-               $item['body'] = self::convertMentions(HTML::toBBCode($activity['content']));
-               $item['location'] = $activity['location'];
-               $item['tag'] = self::constructTagList($activity['tags'], $activity['sensitive']);
-               $item['app'] = $activity['service'];
-               $item['plink'] = defaults($activity, 'alternate-url', $item['uri']);
-
-               $item = self::constructAttachList($activity['attachments'], $item);
-
-               $source = JsonLD::fetchElement($activity, 'source', 'content', 'mediaType', 'text/bbcode');
-               if (!empty($source)) {
-                       $item['body'] = $source;
-               }
-
-               $item['protocol'] = Conversation::PARCEL_ACTIVITYPUB;
-               $item['source'] = $body;
-               $item['conversation-uri'] = $activity['conversation'];
-
-               foreach ($activity['receiver'] as $receiver) {
-                       $item['uid'] = $receiver;
-                       $item['contact-id'] = Contact::getIdForURL($activity['author'], $receiver, true);
-
-                       if (($receiver != 0) && empty($item['contact-id'])) {
-                               $item['contact-id'] = Contact::getIdForURL($activity['author'], 0, true);
-                       }
-
-                       $item_id = Item::insert($item);
-                       logger('Storing for user ' . $item['uid'] . ': ' . $item_id);
-               }
-       }
-
-       private static function fetchMissingActivity($url, $child)
-       {
-               $object = ActivityPub::fetchContent($url);
-               if (empty($object)) {
-                       logger('Activity ' . $url . ' was not fetchable, aborting.');
-                       return;
-               }
-
-               $activity = [];
-               $activity['@context'] = $object['@context'];
-               unset($object['@context']);
-               $activity['id'] = $object['id'];
-               $activity['to'] = defaults($object, 'to', []);
-               $activity['cc'] = defaults($object, 'cc', []);
-               $activity['actor'] = $child['author'];
-               $activity['object'] = $object;
-               $activity['published'] = $object['published'];
-               $activity['type'] = 'Create';
-
-               self::processActivity($activity);
-               logger('Activity ' . $url . ' had been fetched and processed.');
-       }
-
-       private static function getUserOfObject($object)
-       {
-               $self = DBA::selectFirst('contact', ['uid'], ['nurl' => normalise_link($object), 'self' => true]);
-               if (!DBA::isResult($self)) {
-                       return false;
-               } else {
-                       return $self['uid'];
-               }
-       }
-
-       private static function followUser($activity)
-       {
-               $uid = self::getUserOfObject($activity['object']);
-               if (empty($uid)) {
-                       return;
-               }
-
-               $owner = User::getOwnerDataById($uid);
-
-               $cid = Contact::getIdForURL($activity['owner'], $uid);
-               if (!empty($cid)) {
-                       $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
-               } else {
-                       $contact = false;
-               }
-
-               $item = ['author-id' => Contact::getIdForURL($activity['owner']),
-                       'author-link' => $activity['owner']];
-
-               Contact::addRelationship($owner, $contact, $item);
-               $cid = Contact::getIdForURL($activity['owner'], $uid);
-               if (empty($cid)) {
-                       return;
-               }
-
-               $contact = DBA::selectFirst('contact', ['network'], ['id' => $cid]);
-               if ($contact['network'] != Protocol::ACTIVITYPUB) {
-                       Contact::updateFromProbe($cid, Protocol::ACTIVITYPUB);
-               }
-
-               DBA::update('contact', ['hub-verify' => $activity['id']], ['id' => $cid]);
-               logger('Follow user ' . $uid . ' from contact ' . $cid . ' with id ' . $activity['id']);
-       }
-
-       private static function acceptFollowUser($activity)
-       {
-               $uid = self::getUserOfObject($activity['object']);
-               if (empty($uid)) {
-                       return;
-               }
-
-               $owner = User::getOwnerDataById($uid);
-
-               $cid = Contact::getIdForURL($activity['owner'], $uid);
-               if (empty($cid)) {
-                       logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
-                       return;
-               }
-
-               $fields = ['pending' => false];
-
-               $contact = DBA::selectFirst('contact', ['rel'], ['id' => $cid]);
-               if ($contact['rel'] == Contact::FOLLOWER) {
-                       $fields['rel'] = Contact::FRIEND;
-               }
-
-               $condition = ['id' => $cid];
-               DBA::update('contact', $fields, $condition);
-               logger('Accept contact request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
-       }
-
-       private static function undoFollowUser($activity)
-       {
-               $uid = self::getUserOfObject($activity['object']);
-               if (empty($uid)) {
-                       return;
-               }
-
-               $owner = User::getOwnerDataById($uid);
-
-               $cid = Contact::getIdForURL($activity['owner'], $uid);
-               if (empty($cid)) {
-                       logger('No contact found for ' . $activity['owner'], LOGGER_DEBUG);
-                       return;
-               }
-
-               $contact = DBA::selectFirst('contact', [], ['id' => $cid]);
-               if (!DBA::isResult($contact)) {
-                       return;
-               }
-
-               Contact::removeFollower($owner, $contact);
-               logger('Undo following request from contact ' . $cid . ' for user ' . $uid, LOGGER_DEBUG);
        }
 }