diff --git a/include/items.php b/include/items.php
index 4a76cb9090..cbd3883db2 100644
--- a/include/items.php
+++ b/include/items.php
@@ -14,6 +14,7 @@ use Friendica\Model\GContact;
 use Friendica\Model\Group;
 use Friendica\Model\Term;
 use Friendica\Model\User;
+use Friendica\Model\Item;
 use Friendica\Object\Image;
 use Friendica\Protocol\DFRN;
 use Friendica\Protocol\OStatus;
@@ -1124,9 +1125,9 @@ function item_store($arr, $force_parent = false, $notify = false, $dontcache = f
 	}
 
 	if ($arr['parent-uri'] === $arr['uri']) {
-		add_shadow_thread($current_post);
+		Item::addShadow($current_post);
 	} else {
-		add_shadow_entry($current_post);
+		Item::addShadowPost($current_post);
 	}
 
 	check_user_notification($current_post);
diff --git a/include/threads.php b/include/threads.php
index 7c20018259..61bc5292ff 100644
--- a/include/threads.php
+++ b/include/threads.php
@@ -1,9 +1,6 @@
 <?php
 
-use Friendica\App;
-use Friendica\Core\System;
 use Friendica\Database\DBM;
-use Friendica\Model\Contact;
 
 function add_thread($itemid, $onlyshadow = false) {
 	$items = q("SELECT `uid`, `created`, `edited`, `commented`, `received`, `changed`, `wall`, `private`, `pubmail`,
@@ -24,158 +21,6 @@ function add_thread($itemid, $onlyshadow = false) {
 	}
 }
 
-/**
- * @brief Add a shadow entry for a given item id that is a thread starter
- *
- * We store every public item entry additionally with the user id "0".
- * This is used for the community page and for the search.
- * It is planned that in the future we will store public item entries only once.
- *
- * @param integer $itemid Item ID that should be added
- */
-function add_shadow_thread($itemid) {
-	$items = q("SELECT `uid`, `wall`, `private`, `moderated`, `visible`, `contact-id`, `deleted`, `network`, `author-id`, `owner-id`
-		FROM `item` WHERE `id` = %d AND (`parent` = %d OR `parent` = 0) LIMIT 1", intval($itemid), intval($itemid));
-
-	if (!DBM::is_result($items)) {
-		return;
-	}
-
-	$item = $items[0];
-
-	// is it already a copy?
-	if (($itemid == 0) || ($item['uid'] == 0)) {
-		return;
-	}
-
-	// Is it a visible public post?
-	if (!$item["visible"] || $item["deleted"] || $item["moderated"] || $item["private"]) {
-		return;
-	}
-
-	// is it an entry from a connector? Only add an entry for natively connected networks
-	if (!in_array($item["network"], [NETWORK_DFRN, NETWORK_DIASPORA, NETWORK_OSTATUS, ""])) {
-		return;
-	}
-
-	// Is the public contact configured as hidden?
-        if (Contact::isHidden($item["owner-id"]) || Contact::isHidden($item["author-id"])) {
-                return;
-        }
-
-	// Only do these checks if the post isn't a wall post
-	if (!$item["wall"]) {
-		// Check, if hide-friends is activated - then don't do a shadow entry
-		$r = q("SELECT `hide-friends` FROM `profile` WHERE `is-default` AND `uid` = %d AND NOT `hide-friends`",
-			$item['uid']);
-
-		if (!DBM::is_result($r)) {
-			return;
-		}
-
-		// Check if the contact is hidden or blocked
-		$r = q("SELECT `id` FROM `contact` WHERE NOT `hidden` AND NOT `blocked` AND `id` = %d",
-			$item['contact-id']);
-
-		if (!DBM::is_result($r)) {
-			return;
-		}
-	}
-
-	// Only add a shadow, if the profile isn't hidden
-	$r = q("SELECT `uid` FROM `user` where `uid` = %d AND NOT `hidewall`", $item['uid']);
-	if (!DBM::is_result($r)) {
-		return;
-	}
-
-	$item = q("SELECT * FROM `item` WHERE `id` = %d", intval($itemid));
-
-	if (count($item) && ($item[0]["allow_cid"] == '')  && ($item[0]["allow_gid"] == '') &&
-		($item[0]["deny_cid"] == '') && ($item[0]["deny_gid"] == '')) {
-
-		$r = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `uid` = 0 LIMIT 1",
-			dbesc($item['uri']));
-
-		if (!DBM::is_result($r)) {
-			// Preparing public shadow (removing user specific data)
-			require_once("include/items.php");
-
-			unset($item[0]['id']);
-			$item[0]['uid'] = 0;
-			$item[0]['origin'] = 0;
-			$item[0]['wall'] = 0;
-			$item[0]['contact-id'] = Contact::getIdForURL($item[0]['author-link'], 0);
-
-			if (in_array($item[0]['type'], ["net-comment", "wall-comment"])) {
-				$item[0]['type'] = 'remote-comment';
-			} elseif ($item[0]['type'] == 'wall') {
-				$item[0]['type'] = 'remote';
-			}
-
-			$public_shadow = item_store($item[0], false, false, true);
-
-			logger("Stored public shadow for thread ".$itemid." under id ".$public_shadow, LOGGER_DEBUG);
-		}
-	}
-}
-
-/**
- * @brief Add a shadow entry for a given item id that is a comment
- *
- * This function does the same like the function above - but for comments
- *
- * @param integer $itemid Item ID that should be added
- */
-function add_shadow_entry($itemid) {
-
-	$items = q("SELECT * FROM `item` WHERE `id` = %d", intval($itemid));
-
-	if (!DBM::is_result($items)) {
-		return;
-	}
-
-	$item = $items[0];
-
-	// Is it a toplevel post?
-	if ($item['id'] == $item['parent']) {
-		add_shadow_thread($itemid);
-		return;
-	}
-
-	// Is this a shadow entry?
-	if ($item['uid'] == 0)
-		return;
-
-	// Is there a shadow parent?
-	$r = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `uid` = 0 LIMIT 1", dbesc($item['parent-uri']));
-	if (!DBM::is_result($r))
-		return;
-
-	// Is there already a shadow entry?
-	$r = q("SELECT `id` FROM `item` WHERE `uri` = '%s' AND `uid` = 0 LIMIT 1", dbesc($item['uri']));
-	if (DBM::is_result($r))
-		return;
-
-	// Preparing public shadow (removing user specific data)
-	require_once("include/items.php");
-
-	unset($item['id']);
-	$item['uid'] = 0;
-	$item['origin'] = 0;
-	$item['wall'] = 0;
-	$item['contact-id'] = Contact::getIdForURL($item['author-link'], 0);
-
-	if (in_array($item['type'], ["net-comment", "wall-comment"])) {
-		$item['type'] = 'remote-comment';
-	} elseif ($item['type'] == 'wall') {
-		$item['type'] = 'remote';
-	}
-
-	$public_shadow = item_store($item, false, false, true);
-
-	logger("Stored public shadow for comment ".$item['uri']." under id ".$public_shadow, LOGGER_DEBUG);
-}
-
 function update_thread_uri($itemuri, $uid) {
 	$messages = q("SELECT `id` FROM `item` WHERE uri ='%s' AND uid=%d", dbesc($itemuri), intval($uid));
 
@@ -266,47 +111,3 @@ function delete_thread($itemid, $itemuri = "") {
 		}
 	}
 }
-
-function update_threads() {
-	logger("update_threads: start");
-
-	$messages = dba::select('item', ['id'], ["`id` = `parent`"]);
-
-	logger("update_threads: fetched messages: ".dba::num_rows($messages));
-
-	while ($message = dba::fetch($messages)) {
-		add_thread($message["id"]);
-		add_shadow_thread($message["id"]);
-	}
-	dba::close($messages);
-}
-
-function update_threads_mention() {
-	$users = q("SELECT `uid`, `nickname` FROM `user` ORDER BY `uid`");
-
-	foreach ($users AS $user) {
-		$self = normalise_link(System::baseUrl() . '/profile/' . $user['nickname']);
-		$selfhttps = str_replace("http://", "https://", $self);
-		$parents = q("SELECT DISTINCT(`parent`) FROM `item` WHERE `uid` = %d AND
-				((`owner-link` IN ('%s', '%s')) OR (`author-link` IN ('%s', '%s')))",
-				$user["uid"], $self, $selfhttps, $self, $selfhttps);
-
-		foreach ($parents AS $parent)
-			q("UPDATE `thread` SET `mention` = 1 WHERE `iid` = %d", $parent["parent"]);
-	}
-}
-
-
-function update_shadow_copy() {
-	logger("start");
-
-	$condition = "`uid` != 0 AND `network` IN ('', ?, ?, ?) AND `visible` AND NOT `deleted` AND NOT `moderated` AND NOT `private`";
-	$messages = dba::select('thread', ['iid'], [$condition, NETWORK_DFRN, NETWORK_DIASPORA, NETWORK_OSTATUS],
-				['order' => 'created']);
-
-	logger("fetched messages: ".dba::num_rows($messages));
-	while ($message = dba::fetch($messages))
-		add_shadow_thread($message["iid"]);
-
-	dba::close($messages);
-}
diff --git a/src/Model/Item.php b/src/Model/Item.php
index 2ad610ccac..19225beab5 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -8,6 +8,8 @@ namespace Friendica\Model;
 
 use Friendica\Core\Worker;
 use Friendica\Model\Term;
+use Friendica\Model\Contact;
+use Friendica\Database\DBM;
 use dba;
 
 require_once 'include/tags.php';
@@ -60,4 +62,141 @@ class Item
 
 		return $rows;
 	}
+
+	/**
+	 * @brief Add a shadow entry for a given item id that is a thread starter
+	 *
+	 * We store every public item entry additionally with the user id "0".
+	 * This is used for the community page and for the search.
+	 * It is planned that in the future we will store public item entries only once.
+	 *
+	 * @param integer $itemid Item ID that should be added
+	 */
+	public static function addShadow($itemid) {
+		$fields = ['uid', 'wall', 'private', 'moderated', 'visible', 'contact-id', 'deleted', 'network', 'author-id', 'owner-id'];
+		$condition = ["`id` = ? AND (`parent` = ? OR `parent` = 0)", $itemid, $itemid];
+		$item = dba::selectFirst('item', $fields, $condition);
+
+		if (!DBM::is_result($item)) {
+			return;
+		}
+
+		// is it already a copy?
+		if (($itemid == 0) || ($item['uid'] == 0)) {
+			return;
+		}
+
+		// Is it a visible public post?
+		if (!$item["visible"] || $item["deleted"] || $item["moderated"] || $item["private"]) {
+			return;
+		}
+
+		// is it an entry from a connector? Only add an entry for natively connected networks
+		if (!in_array($item["network"], [NETWORK_DFRN, NETWORK_DIASPORA, NETWORK_OSTATUS, ""])) {
+			return;
+		}
+
+		// Is the public contact configured as hidden?
+		if (Contact::isHidden($item["owner-id"]) || Contact::isHidden($item["author-id"])) {
+			return;
+		}
+
+		// Only do these checks if the post isn't a wall post
+		if (!$item["wall"]) {
+			// Check, if hide-friends is activated - then don't do a shadow entry
+			if (dba::exists('profile', ['is-default' => true, 'uid' => $item['uid'], 'hide-friends' => true])) {
+				return;
+			}
+
+			// Check if the contact is hidden or blocked
+			if (!dba::exists('contact', ['hidden' => false, 'blocked' => false, 'id' => $item['contact-id']])) {
+				return;
+			}
+		}
+
+		// Only add a shadow, if the profile isn't hidden
+		if (dba::exists('user', ['uid' => $item['uid'], 'hidewall' => true])) {
+			return;
+		}
+
+		$item = dba::selectFirst('item', [], ['id' => $itemid]);
+
+		if (count($item) && ($item["allow_cid"] == '')  && ($item["allow_gid"] == '') &&
+			($item["deny_cid"] == '') && ($item["deny_gid"] == '')) {
+
+			if (!dba::exists('item', ['uri' => $item['uri'], 'uid' => 0])) {
+				// Preparing public shadow (removing user specific data)
+				require_once("include/items.php");
+
+				unset($item['id']);
+				$item['uid'] = 0;
+				$item['origin'] = 0;
+				$item['wall'] = 0;
+				$item['contact-id'] = Contact::getIdForURL($item['author-link'], 0);
+
+				if (in_array($item['type'], ["net-comment", "wall-comment"])) {
+					$item['type'] = 'remote-comment';
+				} elseif ($item['type'] == 'wall') {
+					$item['type'] = 'remote';
+				}
+
+				$public_shadow = item_store($item, false, false, true);
+
+				logger("Stored public shadow for thread ".$itemid." under id ".$public_shadow, LOGGER_DEBUG);
+			}
+		}
+	}
+
+	/**
+	 * @brief Add a shadow entry for a given item id that is a comment
+	 *
+	 * This function does the same like the function above - but for comments
+	 *
+	 * @param integer $itemid Item ID that should be added
+	 */
+	public static function addShadowPost($itemid) {
+		$item = dba::selectFirst('item', [], ['id' => $itemid]);
+		if (!DBM::is_result($item)) {
+			return;
+		}
+
+		// Is it a toplevel post?
+		if ($item['id'] == $item['parent']) {
+			self::addShadow($itemid);
+			return;
+		}
+
+		// Is this a shadow entry?
+		if ($item['uid'] == 0)
+			return;
+
+		// Is there a shadow parent?
+		if (!dba::exists('item', ['uri' => $item['parent-uri'], 'uid' => 0])) {
+			return;
+		}
+
+		// Is there already a shadow entry?
+		if (dba::exists('item', ['uri' => $item['uri'], 'uid' => 0])) {
+			return;
+		}
+
+		// Preparing public shadow (removing user specific data)
+		require_once("include/items.php");
+
+		unset($item['id']);
+		$item['uid'] = 0;
+		$item['origin'] = 0;
+		$item['wall'] = 0;
+		$item['contact-id'] = Contact::getIdForURL($item['author-link'], 0);
+
+		if (in_array($item['type'], ["net-comment", "wall-comment"])) {
+			$item['type'] = 'remote-comment';
+		} elseif ($item['type'] == 'wall') {
+			$item['type'] = 'remote';
+		}
+
+		$public_shadow = item_store($item, false, false, true);
+
+		logger("Stored public shadow for comment ".$item['uri']." under id ".$public_shadow, LOGGER_DEBUG);
+	}
 }
diff --git a/src/Worker/CreateShadowEntry.php b/src/Worker/CreateShadowEntry.php
index cf95ec622c..97f526a219 100644
--- a/src/Worker/CreateShadowEntry.php
+++ b/src/Worker/CreateShadowEntry.php
@@ -8,7 +8,7 @@
 
 namespace Friendica\Worker;
 
-require_once("include/threads.php");
+use Friendica\Model\Item;
 
 class CreateShadowEntry {
 	public static function execute($message_id = 0) {
@@ -16,6 +16,6 @@ class CreateShadowEntry {
 			return;
 		}
 
-		add_shadow_entry($message_id);
+		Item::addShadowPost($message_id);
 	}
 }
diff --git a/src/Worker/ThreadUpdate.php b/src/Worker/ThreadUpdate.php
deleted file mode 100644
index 30af76399f..0000000000
--- a/src/Worker/ThreadUpdate.php
+++ /dev/null
@@ -1,11 +0,0 @@
-<?php
-namespace Friendica\Worker;
-
-require_once("include/threads.php");
-
-class ThreadUpdate {
-	public static function execute() {
-		update_threads();
-		update_threads_mention();
-	}
-}