ChatInvalidCounter::getNextUser

private function getNextUser(?int $lastId = null): ?int
{
	$query = MessageUnreadTable::query()
		->setSelect(['USER_ID'])
		->setGroup(['USER_ID'])
		->setOrder(['USER_ID'])
		->setLimit(1)
	;

	if (isset($lastId) && $lastId > 0)
	{
		$query->where('USER_ID', '>', $lastId);
	}

	$result = $query->fetch();

	if (!$result || !isset($result['USER_ID']))
	{
		return null;
	}

	return (int)$result['USER_ID'];
}