CBPHelper::SearchUserByName: Bitrix method

      
<?php 
//  CBPHelper :: SearchUserByName()
//  /dist/bitrix/modules/bizproc/classes/general/helper.php:229

    private static function SearchUserByName($user)
    {
        $user = trim($user);
        if (strlen($user) <= 0)
        {
            return [];
        }

        $userId = 0;
        if ($user."|" == intval($user)."|")
        {
            $userId = intval($user);
        }

        if ($userId <= 0)
        {
            $arMatches = [];
            if (preg_match('#\[(\d+)\]#i', $user, $arMatches))
            {
                $userId = intval($arMatches[1]);
            }
        }

        $arResult = [];

        $dbUsers = false;
        if ($userId > 0)
        {
            $arFilter = array("ID_EQUAL_EXACT" => $userId);

            $dbUsers = CUser::GetList(
                ($by = "LAST_NAME"),
                ($order = "asc"),
                $arFilter,
                ['NAV_PARAMS' => false]
            );
        }
        else
        {
            $userLogin = "";
            $arMatches = [];
            if (preg_match('#\((.+?)\)#i', $user, $arMatches))
            {
                $userLogin = $arMatches[1];
                $user = trim(str_replace("(".$userLogin.")", "", $user));
            }

            $userEmail = "";
            $arMatches = [];
            if (preg_match("#<(.+?)>#i", $user, $arMatches))
            {
                if (check_email($arMatches[1]))
                {
                    $userEmail = $arMatches[1];
                    $user = trim(Str_Replace("<".$userEmail.">", "", $user));
                }
            }

            $arUser = [];
            $arUserTmp = explode(" ", $user);
            foreach ($arUserTmp as $s)
            {
                $s = trim($s);
                if (strlen($s) > 0)
                {
                    $arUser[] = $s;
                }
            }
            if (strlen($userLogin) > 0)
            {
                $arUser[] = $userLogin;
            }

            $dbUsers = CUser::SearchUserByName($arUser, $userEmail, true);
        }

        if ($dbUsers)
        {
            while ($arUsers = $dbUsers->GetNext())
            {
                $arResult[] = $arUsers["ID"];
            }
        }

        return $arResult;
    }