]> git.mxchange.org Git - friendica.git/blobdiff - src/Protocol/ActivityPub/Transmitter.php
Merge branch 'post-reason' of github.com:annando/friendica into post-reason
[friendica.git] / src / Protocol / ActivityPub / Transmitter.php
index c65265396ed5068dda232f0fd1d0550e418b974f..ecd18431855713b3bc940d3db9179a0d5c13ee56 100644 (file)
@@ -31,7 +31,6 @@ use Friendica\Database\DBA;
 use Friendica\DI;
 use Friendica\Model\APContact;
 use Friendica\Model\Contact;
-use Friendica\Model\Conversation;
 use Friendica\Model\GServer;
 use Friendica\Model\Item;
 use Friendica\Model\Photo;
@@ -44,7 +43,6 @@ use Friendica\Protocol\ActivityPub;
 use Friendica\Protocol\Relay;
 use Friendica\Util\DateTimeFormat;
 use Friendica\Util\HTTPSignature;
-use Friendica\Util\JsonLD;
 use Friendica\Util\LDSignature;
 use Friendica\Util\Map;
 use Friendica\Util\Network;
@@ -59,13 +57,17 @@ use Friendica\Util\XML;
  */
 class Transmitter
 {
+       const CACHEKEY_FEATURED = 'transmitter:getFeatured:';
+       const CACHEKEY_CONTACTS = 'transmitter:getContacts:';
+       const CACHEKEY_OUTBOX   = 'transmitter:getOutbox:';
+
        /**
         * Add relay servers to the list of inboxes
         *
         * @param array $inboxes
         * @return array inboxes with added relay servers
         */
-       public static function addRelayServerInboxes(array $inboxes = [])
+       public static function addRelayServerInboxes(array $inboxes = []): array
        {
                foreach (Relay::getList(['inbox']) as $contact) {
                        $inboxes[$contact['inbox']] = $contact['inbox'];
@@ -80,7 +82,7 @@ class Transmitter
         * @param array $inboxes
         * @return array inboxes with added relay servers
         */
-       public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = [])
+       public static function addRelayServerInboxesForItem(int $item_id, array $inboxes = []): array
        {
                $item = Post::selectFirst(['uid'], ['id' => $item_id]);
                if (empty($item)) {
@@ -100,12 +102,12 @@ class Transmitter
        }
 
        /**
-        * Subscribe to a relay
+        * Subscribe to a relay and updates contact on success
         *
         * @param string $url Subscribe actor url
         * @return bool success
         */
-       public static function sendRelayFollow(string $url)
+       public static function sendRelayFollow(string $url): bool
        {
                $contact = Contact::getByURL($url);
                if (empty($contact)) {
@@ -122,13 +124,13 @@ class Transmitter
        }
 
        /**
-        * Unsubscribe from a relay
+        * Unsubscribe from a relay and updates contact on success or forced
         *
         * @param string $url   Subscribe actor url
         * @param bool   $force Set the relay status as non follower even if unsubscribe hadn't worked
         * @return bool success
         */
-       public static function sendRelayUndoFollow(string $url, bool $force = false)
+       public static function sendRelayUndoFollow(string $url, bool $force = false): bool
        {
                $contact = Contact::getByURL($url);
                if (empty($contact)) {
@@ -136,6 +138,7 @@ class Transmitter
                }
 
                $success = self::sendContactUndo($url, $contact['id'], 0);
+
                if ($success || $force) {
                        Contact::update(['rel' => Contact::NOTHING], ['id' => $contact['id']]);
                }
@@ -146,17 +149,25 @@ class Transmitter
        /**
         * Collects a list of contacts of the given owner
         *
-        * @param array     $owner     Owner array
-        * @param int|array $rel       The relevant value(s) contact.rel should match
-        * @param string    $module    The name of the relevant AP endpoint module (followers|following)
-        * @param integer   $page      Page number
-        * @param string    $requester URL of the requester
-        *
+        * @param array   $owner     Owner array
+        * @param array   $rel       The relevant value(s) contact.rel should match
+        * @param string  $module    The name of the relevant AP endpoint module (followers|following)
+        * @param integer $page      Page number
+        * @param string  $requester URL of the requester
+        * @param boolean $nocache   Wether to bypass caching
         * @return array of owners
         * @throws \Exception
         */
-       public static function getContacts($owner, $rel, $module, $page = null, string $requester = null)
+       public static function getContacts(array $owner, array $rel, string $module, int $page = null, string $requester = null, bool $nocache = false): array
        {
+               if (empty($page)) {
+                       $cachekey = self::CACHEKEY_CONTACTS . $module . ':'. $owner['uid'];
+                       $result = DI::cache()->get($cachekey);
+                       if (!$nocache && !is_null($result)) {
+                               return $result;
+                       }
+               }
+
                $parameters = [
                        'rel' => $rel,
                        'uid' => $owner['uid'],
@@ -179,6 +190,10 @@ class Transmitter
                $data['type'] = 'OrderedCollection';
                $data['totalItems'] = $total;
 
+               if (!empty($page)) {
+                       $data['id'] .= '?' . http_build_query(['page' => $page]);
+               }
+
                // When we hide our friends we will only show the pure number but don't allow more.
                $show_contacts = empty($owner['hide-friends']);
 
@@ -188,6 +203,10 @@ class Transmitter
                }
 
                if (!$show_contacts) {
+                       if (!empty($cachekey)) {
+                               DI::cache()->set($cachekey, $data, Duration::DAY);
+                       }
+
                        return $data;
                }
 
@@ -203,7 +222,7 @@ class Transmitter
                        }
                        DBA::close($contacts);
 
-                       if (!empty($list)) {
+                       if (count($list) == 100) {
                                $data['next'] = DI::baseUrl() . $modulePath . $owner['nickname'] . '?page=' . ($page + 1);
                        }
 
@@ -212,6 +231,10 @@ class Transmitter
                        $data['orderedItems'] = $list;
                }
 
+               if (!empty($cachekey)) {
+                       DI::cache()->set($cachekey, $data, Duration::DAY);
+               }
+
                return $data;
        }
 
@@ -221,13 +244,21 @@ class Transmitter
         * @param array   $owner     Owner array
         * @param integer $page      Page number
         * @param string  $requester URL of requesting account
-        *
+        * @param boolean $nocache   Wether to bypass caching
         * @return array of posts
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function getOutbox($owner, $page = null, $requester = '')
+       public static function getOutbox(array $owner, int $page = null, string $requester = '', bool $nocache = false): array
        {
+               if (empty($page)) {
+                       $cachekey = self::CACHEKEY_OUTBOX . $owner['uid'];
+                       $result = DI::cache()->get($cachekey);
+                       if (!$nocache && !is_null($result)) {
+                               return $result;
+                       }
+               }
+
                $condition = ['private' => [Item::PUBLIC, Item::UNLISTED]];
 
                if (!empty($requester)) {
@@ -241,15 +272,16 @@ class Transmitter
                        }
                }
 
-               $condition = array_merge($condition,
-                       ['uid'           => $owner['uid'],
+               $condition = array_merge($condition, [
+                       'uid'           => $owner['uid'],
                        'author-id'      => Contact::getIdForURL($owner['url'], 0, false),
                        'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
                        'network'        => Protocol::FEDERATED,
                        'parent-network' => Protocol::FEDERATED,
                        'origin'         => true,
                        'deleted'        => false,
-                       'visible'        => true]);
+                       'visible'        => true
+               ]);
 
                $count = Post::count($condition);
 
@@ -258,6 +290,10 @@ class Transmitter
                $data['type'] = 'OrderedCollection';
                $data['totalItems'] = $count;
 
+               if (!empty($page)) {
+                       $data['id'] .= '?' . http_build_query(['page' => $page]);
+               }
+
                if (empty($page)) {
                        $data['first'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=1';
                } else {
@@ -276,7 +312,7 @@ class Transmitter
                        }
                        DBA::close($items);
 
-                       if (!empty($list)) {
+                       if (count($list) == 20) {
                                $data['next'] = DI::baseUrl() . '/outbox/' . $owner['nickname'] . '?page=' . ($page + 1);
                        }
 
@@ -285,6 +321,95 @@ class Transmitter
                        $data['orderedItems'] = $list;
                }
 
+               if (!empty($cachekey)) {
+                       DI::cache()->set($cachekey, $data, Duration::DAY);
+               }
+
+               return $data;
+       }
+
+       /**
+        * Public posts for the given owner
+        *
+        * @param array   $owner   Owner array
+        * @param integer $page    Page number
+        * @param boolean $nocache Wether to bypass caching
+        *
+        * @return array of posts
+        * @throws \Friendica\Network\HTTPException\InternalServerErrorException
+        * @throws \ImagickException
+        */
+       public static function getFeatured(array $owner, int $page = null, bool $nocache = false): array
+       {
+               if (empty($page)) {
+                       $cachekey = self::CACHEKEY_FEATURED . $owner['uid'];
+                       $result = DI::cache()->get($cachekey);
+                       if (!$nocache && !is_null($result)) {
+                               return $result;
+                       }
+               }
+
+               $owner_cid = Contact::getIdForURL($owner['url'], 0, false);
+
+               $condition = ["`uri-id` IN (SELECT `uri-id` FROM `collection-view` WHERE `cid` = ? AND `type` = ?)",
+                       $owner_cid, Post\Collection::FEATURED];
+
+               $condition = DBA::mergeConditions($condition, [
+                       'uid'           => $owner['uid'],
+                       'author-id'      => $owner_cid,
+                       'private'        => [Item::PUBLIC, Item::UNLISTED],
+                       'gravity'        => [GRAVITY_PARENT, GRAVITY_COMMENT],
+                       'network'        => Protocol::FEDERATED,
+                       'parent-network' => Protocol::FEDERATED,
+                       'origin'         => true,
+                       'deleted'        => false,
+                       'visible'        => true
+               ]);
+
+               $count = Post::count($condition);
+
+               $data = ['@context' => ActivityPub::CONTEXT];
+               $data['id'] = DI::baseUrl() . '/featured/' . $owner['nickname'];
+               $data['type'] = 'OrderedCollection';
+               $data['totalItems'] = $count;
+
+               if (!empty($page)) {
+                       $data['id'] .= '?' . http_build_query(['page' => $page]);
+               }
+
+               if (empty($page)) {
+                       $items = Post::select(['id'], $condition, ['limit' => 20, 'order' => ['created' => true]]);
+               } else {
+                       $data['type'] = 'OrderedCollectionPage';
+                       $items = Post::select(['id'], $condition, ['limit' => [($page - 1) * 20, 20], 'order' => ['created' => true]]);
+               }
+               $list = [];
+
+               while ($item = Post::fetch($items)) {
+                       $activity = self::createActivityFromItem($item['id'], true);
+                       $activity['type'] = $activity['type'] == 'Update' ? 'Create' : $activity['type'];
+
+                       // Only list "Create" activity objects here, no reshares
+                       if (!empty($activity['object']) && ($activity['type'] == 'Create')) {
+                               $list[] = $activity['object'];
+                       }
+               }
+               DBA::close($items);
+
+               if (count($list) == 20) {
+                       $data['next'] = DI::baseUrl() . '/featured/' . $owner['nickname'] . '?page=' . ($page + 1);
+               }
+
+               if (!empty($page)) {
+                       $data['partOf'] = DI::baseUrl() . '/featured/' . $owner['nickname'];
+               }
+
+               $data['orderedItems'] = $list;
+
+               if (!empty($cachekey)) {
+                       DI::cache()->set($cachekey, $data, Duration::DAY);
+               }
+
                return $data;
        }
 
@@ -293,11 +418,13 @@ class Transmitter
         *
         * @return array with service data
         */
-       private static function getService()
+       private static function getService(): array
        {
-               return ['type' => 'Service',
+               return [
+                       'type' => 'Service',
                        'name' =>  FRIENDICA_PLATFORM . " '" . FRIENDICA_CODENAME . "' " . FRIENDICA_VERSION . '-' . DB_UPDATE_VERSION,
-                       'url' => DI::baseUrl()->get()];
+                       'url' => DI::baseUrl()->get()
+               ];
        }
 
        /**
@@ -328,8 +455,9 @@ class Transmitter
                if ($uid != 0) {
                        $data['following'] = DI::baseUrl() . '/following/' . $owner['nick'];
                        $data['followers'] = DI::baseUrl() . '/followers/' . $owner['nick'];
-                       $data['inbox'] = DI::baseUrl() . '/inbox/' . $owner['nick'];
-                       $data['outbox'] = DI::baseUrl() . '/outbox/' . $owner['nick'];
+                       $data['inbox']     = DI::baseUrl() . '/inbox/' . $owner['nick'];
+                       $data['outbox']    = DI::baseUrl() . '/outbox/' . $owner['nick'];
+                       $data['featured']  = DI::baseUrl() . '/featured/' . $owner['nick'];
                } else {
                        $data['inbox'] = DI::baseUrl() . '/friendica/inbox';
                }
@@ -411,7 +539,7 @@ class Transmitter
         * @return array
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       public static function getDeletedUser($username)
+       public static function getDeletedUser(string $username): array
        {
                return [
                        '@context' => ActivityPub::CONTEXT,
@@ -427,12 +555,13 @@ class Transmitter
         * Returns an array with permissions of the thread parent of the given item array
         *
         * @param array $item
+        * @param bool  $is_forum_thread
         *
         * @return array with permissions
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function fetchPermissionBlockFromThreadParent($item)
+       private static function fetchPermissionBlockFromThreadParent(array $item, bool $is_forum_thread): array
        {
                if (empty($item['thr-parent-id'])) {
                        return [];
@@ -462,7 +591,9 @@ class Transmitter
                $type = [Tag::TO => 'to', Tag::CC => 'cc', Tag::BTO => 'bto', Tag::BCC => 'bcc'];
                foreach (Tag::getByURIId($item['thr-parent-id'], [Tag::TO, Tag::CC, Tag::BTO, Tag::BCC]) as $receiver) {
                        if (!empty($parent_profile['followers']) && $receiver['url'] == $parent_profile['followers'] && !empty($item_profile['followers'])) {
-                               $permissions[$type[$receiver['type']]][] = $item_profile['followers'];
+                               if (!$is_forum_thread) {
+                                       $permissions[$type[$receiver['type']]][] = $item_profile['followers'];
+                               }
                        } elseif (!in_array($receiver['url'], $exclude)) {
                                $permissions[$type[$receiver['type']]][] = $receiver['url'];
                        }
@@ -477,7 +608,7 @@ class Transmitter
         * @param integer $item_id
         * @return boolean "true" if the post is from ActivityPub
         */
-       private static function isAPPost(int $item_id)
+       private static function isAPPost(int $item_id): bool
        {
                if (empty($item_id)) {
                        return false;
@@ -497,7 +628,7 @@ class Transmitter
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       private static function createPermissionBlockForItem($item, $blindcopy, $last_id = 0)
+       private static function createPermissionBlockForItem(array $item, bool $blindcopy, int $last_id = 0): array
        {
                if ($last_id == 0) {
                        $last_id = $item['id'];
@@ -523,6 +654,14 @@ class Transmitter
                        $always_bcc = true;
                }
 
+               $parent = Post::selectFirst(['causer-link', 'post-reason'], ['id' => $item['parent']]);
+               if (($parent['post-reason'] == Item::PR_ANNOUNCEMENT) && !empty($parent['causer-link'])) {
+                       $profile = APContact::getByURL($parent['causer-link'], false);
+                       $is_forum_thread = isset($profile['type']) && $profile['type'] == 'Group';
+               } else {
+                       $is_forum_thread = false;
+               }
+
                if (self::isAnnounce($item) || DI::config()->get('debug', 'total_ap_delivery') || self::isAPPost($last_id)) {
                        // Will be activated in a later step
                        $networks = Protocol::FEDERATED;
@@ -553,7 +692,7 @@ class Transmitter
                                $data['cc'][] = $announce['actor']['url'];
                        }
 
-                       $data = array_merge($data, self::fetchPermissionBlockFromThreadParent($item));
+                       $data = array_merge($data, self::fetchPermissionBlockFromThreadParent($item, $is_forum_thread));
 
                        // Check if the item is completely public or unlisted
                        if ($item['private'] == Item::PUBLIC) {
@@ -619,7 +758,7 @@ class Transmitter
                }
 
                if (!empty($item['parent'])) {
-                       $parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']]);
+                       $parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']], ['order' => ['id']]);
                        while ($parent = Post::fetch($parents)) {
                                if ($parent['gravity'] == GRAVITY_PARENT) {
                                        $profile = APContact::getByURL($parent['owner-link'], false);
@@ -633,11 +772,11 @@ class Transmitter
                                                                $data['to'][] = $profile['url'];
                                                        } else {
                                                                $data['cc'][] = $profile['url'];
-                                                               if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])) {
+                                                               if (($item['private'] != Item::PRIVATE) && !empty($actor_profile['followers'])&& !$is_forum_thread) {
                                                                        $data['cc'][] = $actor_profile['followers'];
                                                                }
                                                        }
-                                               } elseif (!$exclusive) {
+                                               } elseif (!$exclusive && !$is_forum_thread) {
                                                        // Public thread parent post always are directed to the followers.
                                                        if ($item['private'] != Item::PRIVATE) {
                                                                $data['cc'][] = $actor_profile['followers'];
@@ -721,10 +860,9 @@ class Transmitter
         * Check if an inbox is archived
         *
         * @param string $url Inbox url
-        *
         * @return boolean "true" if inbox is archived
         */
-       public static function archivedInbox($url)
+       public static function archivedInbox(string $url): bool
        {
                return DBA::exists('inbox-status', ['url' => $url, 'archive' => true]);
        }
@@ -732,12 +870,12 @@ class Transmitter
        /**
         * Check if a given contact should be delivered via AP
         *
-        * @param array $contact
-        * @param array $networks
-        * @return bool
+        * @param array $contact Contact array
+        * @param array $networks Array with networks
+        * @return bool Whether the used protocol matches ACTIVITYPUB
         * @throws Exception
         */
-       private static function isAPContact(array $contact, array $networks)
+       private static function isAPContact(array $contact, array $networks): bool
        {
                if (in_array($contact['network'], $networks) || ($contact['protocol'] == Protocol::ACTIVITYPUB)) {
                        return true;
@@ -752,12 +890,11 @@ class Transmitter
         * @param integer $uid      User ID
         * @param boolean $personal fetch personal inboxes
         * @param boolean $all_ap   Retrieve all AP enabled inboxes
-        *
         * @return array of follower inboxes
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function fetchTargetInboxesforUser($uid, $personal = false, bool $all_ap = false)
+       public static function fetchTargetInboxesforUser(int $uid, bool $personal = false, bool $all_ap = false): array
        {
                $inboxes = [];
 
@@ -778,7 +915,13 @@ class Transmitter
                        $networks = [Protocol::ACTIVITYPUB, Protocol::OSTATUS];
                }
 
-               $condition = ['uid' => $uid, 'archive' => false, 'pending' => false, 'blocked' => false, 'network' => Protocol::FEDERATED];
+               $condition = [
+                       'uid' => $uid,
+                       'archive' => false,
+                       'pending' => false,
+                       'blocked' => false,
+                       'network' => Protocol::FEDERATED,
+               ];
 
                if (!empty($uid)) {
                        $condition['rel'] = [Contact::FOLLOWER, Contact::FRIEND];
@@ -826,7 +969,7 @@ class Transmitter
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function fetchTargetInboxes($item, $uid, $personal = false, $last_id = 0)
+       public static function fetchTargetInboxes(array $item, int $uid, bool $personal = false, int $last_id = 0): array
        {
                $permissions = self::createPermissionBlockForItem($item, true, $last_id);
                if (empty($permissions)) {
@@ -885,12 +1028,11 @@ class Transmitter
        /**
         * Creates an array in the structure of the item table for a given mail id
         *
-        * @param integer $mail_id
-        *
+        * @param integer $mail_id Mail id
         * @return array
         * @throws \Exception
         */
-       public static function ItemArrayFromMail($mail_id, $use_title = false)
+       public static function getItemArrayFromMail(int $mail_id, bool $use_title = false): array
        {
                $mail = DBA::selectFirst('mail', [], ['id' => $mail_id]);
                if (!DBA::isResult($mail)) {
@@ -911,6 +1053,7 @@ class Transmitter
                        $mail['title']        = '';
                }
 
+               $mail['content-warning']  = '';
                $mail['author-link']      = $mail['owner-link'] = $mail['from-url'];
                $mail['owner-id']         = $mail['author-id'];
                $mail['allow_cid']        = '<'.$mail['contact-id'].'>';
@@ -941,9 +1084,9 @@ class Transmitter
         * @return array of activity
         * @throws \Exception
         */
-       public static function createActivityFromMail($mail_id, $object_mode = false)
+       public static function createActivityFromMail(int $mail_id, bool $object_mode = false): array
        {
-               $mail = self::ItemArrayFromMail($mail_id);
+               $mail = self::getItemArrayFromMail($mail_id);
                if (empty($mail)) {
                        return [];
                }
@@ -995,18 +1138,17 @@ class Transmitter
        /**
         * Returns the activity type of a given item
         *
-        * @param array $item
-        *
+        * @param array $item Item array
         * @return string with activity type
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       private static function getTypeOfItem($item)
+       private static function getTypeOfItem(array $item): string
        {
                $reshared = false;
 
                // Only check for a reshare, if it is a real reshare and no quoted reshare
-               if (strpos($item['body'], "[share") === 0) {
+               if (strpos($item['body'], '[share') === 0) {
                        $announce = self::getAnnounceArray($item);
                        $reshared = !empty($announce);
                }
@@ -1045,13 +1187,12 @@ class Transmitter
        /**
         * Creates the activity or fetches it from the cache
         *
-        * @param integer $item_id
+        * @param integer $item_id Item id
         * @param boolean $force Force new cache entry
-        *
-        * @return array with the activity
+        * @return array|false activity or false on failure
         * @throws \Exception
         */
-       public static function createCachedActivityFromItem($item_id, $force = false)
+       public static function createCachedActivityFromItem(int $item_id, bool $force = false)
        {
                $cachekey = 'APDelivery:createActivity:' . $item_id;
 
@@ -1073,7 +1214,6 @@ class Transmitter
         *
         * @param integer $item_id
         * @param boolean $object_mode Is the activity item is used inside another object?
-        *
         * @return false|array
         * @throws \Exception
         */
@@ -1091,30 +1231,22 @@ class Transmitter
                }
 
                if (!$item['deleted']) {
-                       $condition = ['item-uri' => $item['uri'], 'protocol' => Conversation::PARCEL_ACTIVITYPUB];
-                       $conversation = DBA::selectFirst('conversation', ['source'], $condition);
-                       if (!$item['origin'] && DBA::isResult($conversation)) {
-                               $data = json_decode($conversation['source'], true);
-                               if (!empty($data['type'])) {
-                                       if (in_array($data['type'], ['Create', 'Update'])) {
-                                               if ($object_mode) {
-                                                       unset($data['@context']);
-                                                       unset($data['signature']);
-                                               }
-                                               Logger::info('Return stored conversation', ['item' => $item_id]);
-                                               return $data;
-                                       } elseif (in_array('as:' . $data['type'], Receiver::CONTENT_TYPES)) {
-                                               if (!empty($data['@context'])) {
-                                                       $context = $data['@context'];
-                                                       unset($data['@context']);
-                                               }
-                                               unset($data['actor']);
-                                               $object = $data;
-                                       }
+                       $data = Post\Activity::getByURIId($item['uri-id']);
+                       if (!$item['origin'] && !empty($data)) {
+                               if ($object_mode) {
+                                       unset($data['@context']);
+                                       unset($data['signature']);
                                }
+                               Logger::info('Return stored conversation', ['item' => $item_id]);
+                               return $data;
                        }
                }
 
+               if (!$item['origin'] && empty($object)) {
+                       Logger::debug('Post is not ours and is not stored', ['id' => $item_id, 'uri-id' => $item['uri-id']]);
+                       return false;
+               }
+
                $type = self::getTypeOfItem($item);
 
                if (!$object_mode) {
@@ -1130,7 +1262,7 @@ class Transmitter
                }
 
                if ($type == 'Delete') {
-                       $data['id'] = Item::newURI($item['uid'], $item['guid']) . '/' . $type;;
+                       $data['id'] = Item::newURI($item['guid']) . '/' . $type;;
                } elseif (($item['gravity'] == GRAVITY_ACTIVITY) && ($type != 'Undo')) {
                        $data['id'] = $item['uri'];
                } else {
@@ -1153,6 +1285,7 @@ class Transmitter
 
                if (in_array($data['type'], ['Create', 'Update', 'Delete'])) {
                        $data['object'] = $object ?? self::createNote($item);
+                       $data['published'] = DateTimeFormat::utcNow(DateTimeFormat::ATOM);
                } elseif ($data['type'] == 'Add') {
                        $data = self::createAddTag($item, $data);
                } elseif ($data['type'] == 'Announce') {
@@ -1196,11 +1329,10 @@ class Transmitter
        /**
         * Creates a location entry for a given item array
         *
-        * @param array $item
-        *
+        * @param array $item Item array
         * @return array with location array
         */
-       private static function createLocation($item)
+       private static function createLocation(array $item): array
        {
                $location = ['type' => 'Place'];
 
@@ -1230,12 +1362,11 @@ class Transmitter
        /**
         * Returns a tag array for a given item array
         *
-        * @param array $item
-        *
+        * @param array $item Item array
         * @return array of tags
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       private static function createTagList($item)
+       private static function createTagList(array $item): array
        {
                $tags = [];
 
@@ -1277,7 +1408,7 @@ class Transmitter
         * @return array with attachment data
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       private static function createAttachmentList($item, $type)
+       private static function createAttachmentList(array $item, string $type): array
        {
                $attachments = [];
 
@@ -1329,7 +1460,7 @@ class Transmitter
         * @return string Replaced mention
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       private static function mentionAddrCallback($match)
+       private static function mentionAddrCallback(array $match): string
        {
                if (empty($match[1])) {
                        return '';
@@ -1346,11 +1477,10 @@ class Transmitter
        /**
         * Remove image elements since they are added as attachment
         *
-        * @param string $body
-        *
+        * @param string $body HTML code
         * @return string with removed images
         */
-       private static function removePictures($body)
+       private static function removePictures(string $body): string
        {
                // Simplify image codes
                $body = preg_replace("/\[img\=([0-9]*)x([0-9]*)\](.*?)\[\/img\]/ism", '[img]$3[/img]', $body);
@@ -1376,49 +1506,26 @@ class Transmitter
                return $body;
        }
 
-       /**
-        * Fetches the "context" value for a givem item array from the "conversation" table
-        *
-        * @param array $item
-        *
-        * @return string with context url
-        * @throws \Exception
-        */
-       private static function fetchContextURLForItem($item)
-       {
-               $conversation = DBA::selectFirst('conversation', ['conversation-href', 'conversation-uri'], ['item-uri' => $item['parent-uri']]);
-               if (DBA::isResult($conversation) && !empty($conversation['conversation-href'])) {
-                       $context_uri = $conversation['conversation-href'];
-               } elseif (DBA::isResult($conversation) && !empty($conversation['conversation-uri'])) {
-                       $context_uri = $conversation['conversation-uri'];
-               } else {
-                       $context_uri = $item['parent-uri'] . '#context';
-               }
-               return $context_uri;
-       }
-
        /**
         * Returns if the post contains sensitive content ("nsfw")
         *
-        * @param integer $uri_id
-        *
-        * @return boolean
+        * @param integer $uri_id URI id
+        * @return boolean Whether URI id was found
         * @throws \Exception
         */
-       private static function isSensitive($uri_id)
+       private static function isSensitive(int $uri_id): bool
        {
-               return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw']);
+               return DBA::exists('tag-view', ['uri-id' => $uri_id, 'name' => 'nsfw', 'type' => Tag::HASHTAG]);
        }
 
        /**
         * Creates event data
         *
-        * @param array $item
-        *
+        * @param array $item Item array
         * @return array with the event data
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       private static function createEvent($item)
+       private static function createEvent(array $item): array
        {
                $event = [];
                $event['name'] = $item['event-summary'];
@@ -1444,21 +1551,38 @@ class Transmitter
         * Creates a note/article object array
         *
         * @param array $item
-        *
         * @return array with the object data
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function createNote($item)
+       public static function createNote(array $item): array
        {
                if (empty($item)) {
                        return [];
                }
 
+               // We are treating posts differently when they are directed to a community.
+               // This is done to better support Lemmy. Most of the changes should work with other systems as well.
+               // But to not risk compatibility issues we currently perform the changes only for communities.
+               if ($item['gravity'] == GRAVITY_PARENT) {
+                       $isCommunityPost = !empty(Tag::getByURIId($item['uri-id'], [Tag::EXCLUSIVE_MENTION]));
+                       $links = Post\Media::getByURIId($item['uri-id'], [Post\Media::HTML]);
+                       if ($isCommunityPost && (count($links) == 1)) {
+                               $link = $links[0]['url'];
+                       }
+               } else {
+                       $isCommunityPost = false;
+               }
+
                if ($item['event-type'] == 'event') {
                        $type = 'Event';
                } elseif (!empty($item['title'])) {
-                       $type = 'Article';
+                       if (!$isCommunityPost || empty($link)) {
+                               $type = 'Article';
+                       } else {
+                               // "Page" is used by Lemmy for posts that contain an external link
+                               $type = 'Page';
+                       }
                } else {
                        $type = 'Note';
                }
@@ -1490,10 +1614,10 @@ class Transmitter
                        $data['updated'] = DateTimeFormat::utc($item['edited'] . '+00:00', DateTimeFormat::ATOM);
                }
 
-               $data['url'] = $item['plink'];
+               $data['url'] = $link ?? $item['plink'];
                $data['attributedTo'] = $item['author-link'];
                $data['sensitive'] = self::isSensitive($item['uri-id']);
-               $data['context'] = self::fetchContextURLForItem($item);
+               $data['conversation'] = $data['context'] = $item['conversation'];
 
                if (!empty($item['title'])) {
                        $data['name'] = BBCode::toPlaintext($item['title'], false);
@@ -1527,6 +1651,19 @@ class Transmitter
                if ($type == 'Event') {
                        $data = array_merge($data, self::createEvent($item));
                } else {
+                       if ($isCommunityPost) {
+                               // For community posts we remove the visible "!user@domain.tld".
+                               // This improves the look at systems like Lemmy.
+                               // Also in the future we should control the community delivery via other methods.
+                               $body = preg_replace("/!\[url\=[^\[\]]*\][^\[\]]*\[\/url\]/ism", '', $body);
+                       }
+
+                       if ($type == 'Page') {
+                               // When we transmit "Page" posts we have to remove the attachment.
+                               // The attachment contains the link that we already transmit in the "url" field.
+                               $body = preg_replace("/\s*\[attachment .*?\].*?\[\/attachment\]\s*/ism", '', $body);
+                       }
+
                        $body = BBCode::setMentionsToNicknames($body);
 
                        $data['content'] = BBCode::convertForUriId($item['uri-id'], $body, BBCode::ACTIVITYPUB);
@@ -1569,10 +1706,9 @@ class Transmitter
         * Fetches the language from the post, the user or the system.
         *
         * @param array $item
-        *
         * @return string language string
         */
-       private static function getLanguage(array $item)
+       private static function getLanguage(array $item): string
        {
                // Try to fetch the language from the post itself
                if (!empty($item['language'])) {
@@ -1597,74 +1733,71 @@ class Transmitter
        /**
         * Creates an an "add tag" entry
         *
-        * @param array $item
-        * @param array $data activity data
-        *
+        * @param array $item Item array
+        * @param array $activity activity data
         * @return array with activity data for adding tags
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       private static function createAddTag($item, $data)
+       private static function createAddTag(array $item, array $activity): array
        {
                $object = XML::parseString($item['object']);
-               $target = XML::parseString($item["target"]);
+               $target = XML::parseString($item['target']);
 
-               $data['diaspora:guid'] = $item['guid'];
-               $data['actor'] = $item['author-link'];
-               $data['target'] = (string)$target->id;
-               $data['summary'] = BBCode::toPlaintext($item['body']);
-               $data['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
+               $activity['diaspora:guid'] = $item['guid'];
+               $activity['actor'] = $item['author-link'];
+               $activity['target'] = (string)$target->id;
+               $activity['summary'] = BBCode::toPlaintext($item['body']);
+               $activity['object'] = ['id' => (string)$object->id, 'type' => 'tag', 'name' => (string)$object->title, 'content' => (string)$object->content];
 
-               return $data;
+               return $activity;
        }
 
        /**
         * Creates an announce object entry
         *
-        * @param array $item
-        * @param array $data activity data
-        *
+        * @param array $item Item array
+        * @param array $activity activity data
         * @return array with activity data
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       private static function createAnnounce($item, $data)
+       private static function createAnnounce(array $item, array $activity): array
        {
                $orig_body = $item['body'];
                $announce = self::getAnnounceArray($item);
                if (empty($announce)) {
-                       $data['type'] = 'Create';
-                       $data['object'] = self::createNote($item);
-                       return $data;
+                       $activity['type'] = 'Create';
+                       $activity['object'] = self::createNote($item);
+                       return $activity;
                }
 
                if (empty($announce['comment'])) {
                        // Pure announce, without a quote
-                       $data['type'] = 'Announce';
-                       $data['object'] = $announce['object']['uri'];
-                       return $data;
+                       $activity['type'] = 'Announce';
+                       $activity['object'] = $announce['object']['uri'];
+                       return $activity;
                }
 
                // Quote
-               $data['type'] = 'Create';
+               $activity['type'] = 'Create';
                $item['body'] = $announce['comment'] . "\n" . $announce['object']['plink'];
-               $data['object'] = self::createNote($item);
+               $activity['object'] = self::createNote($item);
 
                /// @todo Finally descide how to implement this in AP. This is a possible way:
-               $data['object']['attachment'][] = self::createNote($announce['object']);
+               $activity['object']['attachment'][] = self::createNote($announce['object']);
 
-               $data['object']['source']['content'] = $orig_body;
-               return $data;
+               $activity['object']['source']['content'] = $orig_body;
+               return $activity;
        }
 
        /**
         * Return announce related data if the item is an annunce
         *
         * @param array $item
-        *
-        * @return array
+        * @return array Announcement array
         */
-       public static function getAnnounceArray($item)
+       public static function getAnnounceArray(array $item): array
        {
                $reshared = Item::getShareArray($item);
                if (empty($reshared['guid'])) {
@@ -1691,11 +1824,10 @@ class Transmitter
        /**
         * Checks if the provided item array is an announce
         *
-        * @param array $item
-        *
-        * @return boolean
+        * @param array $item Item array
+        * @return boolean Whether item is an announcement
         */
-       public static function isAnnounce($item)
+       public static function isAnnounce(array $item): bool
        {
                if (!empty($item['verb']) && ($item['verb'] == Activity::ANNOUNCE)) {
                        return true;
@@ -1716,7 +1848,7 @@ class Transmitter
         *
         * @return bool|string activity id
         */
-       public static function activityIDFromContact($cid)
+       public static function activityIDFromContact(int $cid)
        {
                $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
                if (!DBA::isResult($contact)) {
@@ -1734,17 +1866,17 @@ class Transmitter
         * @param integer $uid           User ID
         * @param string  $inbox         Target inbox
         * @param integer $suggestion_id Suggestion ID
-        *
         * @return boolean was the transmission successful?
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       public static function sendContactSuggestion($uid, $inbox, $suggestion_id)
+       public static function sendContactSuggestion(int $uid, string $inbox, int $suggestion_id): bool
        {
                $owner = User::getOwnerDataById($uid);
 
                $suggestion = DI::fsuggest()->selectOneById($suggestion_id);
 
-               $data = ['@context' => ActivityPub::CONTEXT,
+               $data = [
+                       '@context' => ActivityPub::CONTEXT,
                        'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
                        'type' => 'Announce',
                        'actor' => $owner['url'],
@@ -1752,7 +1884,8 @@ class Transmitter
                        'content' => $suggestion->note,
                        'instrument' => self::getService(),
                        'to' => [ActivityPub::PUBLIC_COLLECTION],
-                       'cc' => []];
+                       'cc' => []
+               ];
 
                $signed = LDSignature::sign($data, $owner);
 
@@ -1765,15 +1898,15 @@ class Transmitter
         *
         * @param integer $uid   User ID
         * @param string  $inbox Target inbox
-        *
         * @return boolean was the transmission successful?
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       public static function sendProfileRelocation($uid, $inbox)
+       public static function sendProfileRelocation(int $uid, string $inbox): bool
        {
                $owner = User::getOwnerDataById($uid);
 
-               $data = ['@context' => ActivityPub::CONTEXT,
+               $data = [
+                       '@context' => ActivityPub::CONTEXT,
                        'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
                        'type' => 'dfrn:relocate',
                        'actor' => $owner['url'],
@@ -1781,7 +1914,8 @@ class Transmitter
                        'published' => DateTimeFormat::utcNow(DateTimeFormat::ATOM),
                        'instrument' => self::getService(),
                        'to' => [ActivityPub::PUBLIC_COLLECTION],
-                       'cc' => []];
+                       'cc' => []
+               ];
 
                $signed = LDSignature::sign($data, $owner);
 
@@ -1794,11 +1928,10 @@ class Transmitter
         *
         * @param integer $uid   User ID
         * @param string  $inbox Target inbox
-        *
         * @return boolean was the transmission successful?
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         */
-       public static function sendProfileDeletion($uid, $inbox)
+       public static function sendProfileDeletion(int $uid, string $inbox): bool
        {
                $owner = User::getOwnerDataById($uid);
 
@@ -1833,7 +1966,6 @@ class Transmitter
         *
         * @param integer $uid   User ID
         * @param string  $inbox Target inbox
-        *
         * @return boolean was the transmission successful?
         * @throws HTTPException\InternalServerErrorException
         * @throws HTTPException\NotFoundException
@@ -1866,17 +1998,18 @@ class Transmitter
         * @param string  $activity Type name
         * @param string  $target   Target profile
         * @param integer $uid      User ID
+        * @param string  $id Activity-identifier
         * @return bool
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         * @throws \Exception
         */
-       public static function sendActivity($activity, $target, $uid, $id = '')
+       public static function sendActivity(string $activity, string $target, int $uid, string $id = ''): bool
        {
                $profile = APContact::getByURL($target);
                if (empty($profile['inbox'])) {
                        Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
-                       return;
+                       return false;
                }
 
                $owner = User::getOwnerDataById($uid);
@@ -1885,13 +2018,15 @@ class Transmitter
                        $id = DI::baseUrl() . '/activity/' . System::createGUID();
                }
 
-               $data = ['@context' => ActivityPub::CONTEXT,
+               $data = [
+                       '@context' => ActivityPub::CONTEXT,
                        'id' => $id,
                        'type' => $activity,
                        'actor' => $owner['url'],
                        'object' => $profile['url'],
                        'instrument' => self::getService(),
-                       'to' => [$profile['url']]];
+                       'to' => [$profile['url']],
+               ];
 
                Logger::info('Sending activity ' . $activity . ' to ' . $target . ' for user ' . $uid);
 
@@ -1911,12 +2046,12 @@ class Transmitter
         * @throws \ImagickException
         * @throws \Exception
         */
-       public static function sendFollowObject($object, $target, $uid = 0)
+       public static function sendFollowObject(string $object, string $target, int $uid = 0): bool
        {
                $profile = APContact::getByURL($target);
                if (empty($profile['inbox'])) {
                        Logger::warning('No inbox found for target', ['target' => $target, 'profile' => $profile]);
-                       return;
+                       return false;
                }
 
                if (empty($uid)) {
@@ -1938,13 +2073,15 @@ class Transmitter
 
                $owner = User::getOwnerDataById($uid);
 
-               $data = ['@context' => ActivityPub::CONTEXT,
+               $data = [
+                       '@context' => ActivityPub::CONTEXT,
                        'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
                        'type' => 'Follow',
                        'actor' => $owner['url'],
                        'object' => $object,
                        'instrument' => self::getService(),
-                       'to' => [$profile['url']]];
+                       'to' => [$profile['url']],
+               ];
 
                Logger::info('Sending follow ' . $object . ' to ' . $target . ' for user ' . $uid);
 
@@ -1956,12 +2093,13 @@ class Transmitter
         * Transmit a message that the contact request had been accepted
         *
         * @param string  $target Target profile
-        * @param         $id
+        * @param string  $id Object id
         * @param integer $uid    User ID
+        * @return void
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function sendContactAccept($target, $id, $uid)
+       public static function sendContactAccept(string $target, string $id, int $uid)
        {
                $profile = APContact::getByURL($target);
                if (empty($profile['inbox'])) {
@@ -1970,18 +2108,20 @@ class Transmitter
                }
 
                $owner = User::getOwnerDataById($uid);
-               $data = ['@context' => ActivityPub::CONTEXT,
+               $data = [
+                       '@context' => ActivityPub::CONTEXT,
                        'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
                        'type' => 'Accept',
                        'actor' => $owner['url'],
                        'object' => [
-                               'id' => (string)$id,
+                               'id' => $id,
                                'type' => 'Follow',
                                'actor' => $profile['url'],
                                'object' => $owner['url']
                        ],
                        'instrument' => self::getService(),
-                       'to' => [$profile['url']]];
+                       'to' => [$profile['url']],
+               ];
 
                Logger::debug('Sending accept to ' . $target . ' for user ' . $uid . ' with id ' . $id);
 
@@ -1992,14 +2132,14 @@ class Transmitter
        /**
         * Reject a contact request or terminates the contact relation
         *
-        * @param string  $target Target profile
-        * @param         $id
-        * @param integer $uid    User ID
+        * @param string $target   Target profile
+        * @param string $objectId Object id
+        * @param int    $uid      User ID
         * @return bool Operation success
         * @throws HTTPException\InternalServerErrorException
         * @throws \ImagickException
         */
-       public static function sendContactReject($target, $id, $uid): bool
+       public static function sendContactReject(string $target, string $objectId, int $uid): bool
        {
                $profile = APContact::getByURL($target);
                if (empty($profile['inbox'])) {
@@ -2008,20 +2148,22 @@ class Transmitter
                }
 
                $owner = User::getOwnerDataById($uid);
-               $data = ['@context' => ActivityPub::CONTEXT,
+               $data = [
+                       '@context' => ActivityPub::CONTEXT,
                        'id' => DI::baseUrl() . '/activity/' . System::createGUID(),
                        'type' => 'Reject',
-                       'actor' => $owner['url'],
+                       'actor'  => $owner['url'],
                        'object' => [
-                               'id' => (string)$id,
+                               'id' => $objectId,
                                'type' => 'Follow',
                                'actor' => $profile['url'],
                                'object' => $owner['url']
                        ],
                        'instrument' => self::getService(),
-                       'to' => [$profile['url']]];
+                       'to' => [$profile['url']],
+               ];
 
-               Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $id);
+               Logger::debug('Sending reject to ' . $target . ' for user ' . $uid . ' with id ' . $objectId);
 
                $signed = LDSignature::sign($data, $owner);
                return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
@@ -2031,13 +2173,14 @@ class Transmitter
         * Transmits a message that we don't want to follow this contact anymore
         *
         * @param string  $target Target profile
+        * @param integer $cid    Contact id
         * @param integer $uid    User ID
+        * @return bool success
         * @throws \Friendica\Network\HTTPException\InternalServerErrorException
         * @throws \ImagickException
         * @throws \Exception
-        * @return bool success
         */
-       public static function sendContactUndo($target, $cid, $uid)
+       public static function sendContactUndo(string $target, int $cid, int $uid): bool
        {
                $profile = APContact::getByURL($target);
                if (empty($profile['inbox'])) {
@@ -2050,26 +2193,39 @@ class Transmitter
                        return false;
                }
 
-               $id = DI::baseUrl() . '/activity/' . System::createGUID();
+               $objectId = DI::baseUrl() . '/activity/' . System::createGUID();
 
                $owner = User::getOwnerDataById($uid);
-               $data = ['@context' => ActivityPub::CONTEXT,
-                       'id' => $id,
+               $data = [
+                       '@context' => ActivityPub::CONTEXT,
+                       'id' => $objectId,
                        'type' => 'Undo',
                        'actor' => $owner['url'],
-                       'object' => ['id' => $object_id, 'type' => 'Follow',
+                       'object' => [
+                               'id' => $object_id,
+                               'type' => 'Follow',
                                'actor' => $owner['url'],
-                               'object' => $profile['url']],
+                               'object' => $profile['url']
+                       ],
                        'instrument' => self::getService(),
-                       'to' => [$profile['url']]];
+                       'to' => [$profile['url']],
+               ];
 
-               Logger::info('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $id);
+               Logger::info('Sending undo to ' . $target . ' for user ' . $uid . ' with id ' . $objectId);
 
                $signed = LDSignature::sign($data, $owner);
                return HTTPSignature::transmit($signed, $profile['inbox'], $uid);
        }
 
-       private static function prependMentions($body, int $uriid, string $authorLink)
+       /**
+        * Prepends mentions (@) to $body variable
+        *
+        * @param string $body HTML code
+        * @param int    $uriId
+        * @param string $authorLink Author link
+        * @return string HTML code with prepended mentions
+        */
+       private static function prependMentions(string $body, int $uriid, string $authorLink): string
        {
                $mentions = [];