/**
* Starts session for admin user
* @param int $user_id
* @return string session id
*/
public function startSession($user_id)
{
$this->deleteOldSessions();
$user_id = (int) $user_id;
$sid = $this->generateUserSid($user_id);
$session = UsersSessionEntityRepository::findOneEntityByCriteria(['sid' => $sid, 'user_id' => $user_id]);
if (!$session) {
$session = new UsersSessionEntity();
}
$session->setSid($sid);
$session->setUserId($user_id);
$session->save();
return $sid;
}