+ // Fetch the original id of the object
+ $activity = ActivityPub::fetchContent($announce['plink'], $item['uid']);
+ if (!empty($activity)) {
+ $ldactivity = JsonLD::compact($activity);
+ $id = JsonLD::fetchElement($ldactivity, '@id');
+ if (!empty($id)) {
+ return $id;
+ }
+ }
+
+ return self::createNote($item);
+ }
+
+ /**
+ * Creates an activity id for a given contact id
+ *
+ * @param integer $cid Contact ID of target
+ *
+ * @return bool|string activity id
+ */
+ public static function activityIDFromContact($cid)
+ {
+ $contact = DBA::selectFirst('contact', ['uid', 'id', 'created'], ['id' => $cid]);
+ if (!DBA::isResult($contact)) {
+ return false;
+ }
+
+ $hash = hash('ripemd128', $contact['uid'].'-'.$contact['id'].'-'.$contact['created']);
+ $uuid = substr($hash, 0, 8). '-' . substr($hash, 8, 4) . '-' . substr($hash, 12, 4) . '-' . substr($hash, 16, 4) . '-' . substr($hash, 20, 12);
+ return System::baseUrl() . '/activity/' . $uuid;