Chat::filterUsersToAdd

protected function filterUsersToAdd(array $userIds): array
{
	$usersAlreadyInChat = $this->getRelations()->getUserIds();
	$usersToAdd = [];

	foreach ($userIds as $userId)
	{
		$userId = (int)$userId;
		if (!isset($usersAlreadyInChat[$userId]) && $userId > 0)
		{
			$user = ImV2EntityUserUser::getInstance($userId);
			if ($user->isExist() && $user->isActive())
			{
				$usersToAdd[$userId] = $userId;
			}
		}
	}

	return $usersToAdd;
}