Chat::getUserId

protected function getUserId($user): int
{
	$userId = 0;
	if ($user === null)
	{
		$userId = $this->getContext()->getUserId();
	}
	elseif (is_numeric($user))
	{
		$userId = (int)$user;
	}
	elseif ($user instanceof User)
	{
		$userId = $user->getId();
	}

	return $userId;
}