Vergi kimlik no doğrulama

vergi_kimlik_no_dogrulama.php

<?php 
function vergiKimlikDogrulama($vkno) {

    $vkno = preg_replace('/\D/ui','',$vkno);
    if (strlen($vkno) == 10) {
        $vkno_array = str_split(strval($vkno));
        $v1 = (intval($vkno_array[0]) + 9) % 10;
        $v2 = (intval($vkno_array[1]) + 8) % 10;
        $v3 = (intval($vkno_array[2]) + 7) % 10;
        $v4 = (intval($vkno_array[3]) + 6) % 10;
        $v5 = (intval($vkno_array[4]) + 5) % 10;
        $v6 = (intval($vkno_array[5]) + 4) % 10;
        $v7 = (intval($vkno_array[6]) + 3) % 10;
        $v8 = (intval($vkno_array[7]) + 2) % 10;
        $v9 = (intval($vkno_array[8]) + 1) % 10;
        $v_last_digit = intval($vkno_array[9]);

        $v11 = ($v1 * 512) % 9;
        $v22 = ($v2 * 256) % 9;
        $v33 = ($v3 * 128) % 9;
        $v44 = ($v4 * 64) % 9;
        $v55 = ($v5 * 32) % 9;
        $v66 = ($v6 * 16) % 9;
        $v77 = ($v7 * 8) % 9;
        $v88 = ($v8 * 4) % 9;
        $v99 = ($v9 * 2) % 9;

        if ($v1 != 0 && $v11 == 0) $v11 = 9;
        if ($v2 != 0 && $v22 == 0) $v22 = 9;
        if ($v3 != 0 && $v33 == 0) $v33 = 9;
        if ($v4 != 0 && $v44 == 0) $v44 = 9;
        if ($v5 != 0 && $v55 == 0) $v55 = 9;
        if ($v6 != 0 && $v66 == 0) $v66 = 9;
        if ($v7 != 0 && $v77 == 0) $v77 = 9;
        if ($v8 != 0 && $v88 == 0) $v88 = 9;
        if ($v9 != 0 && $v99 == 0) $v99 = 9;
        $toplam = $v11 + $v22 + $v33 + $v44 + $v55 + $v66 + $v77 + $v88 + $v99;

        if ($toplam % 10 == 0) {
            $toplam = 0;
        } else {
            $toplam = (10 - ($toplam % 10));
        }
        if ($toplam == $v_last_digit) {
            return true;
        } else {
            return false;
        }
    } else{ 
        return false;
    }
}

$valid_samples = array(
     '0540033975', '0540033887', '0680066825', '1670068615', '3950079269', '3950079068', '4540017830', '4540017847', 
     '4780040920', '4870003769', '4870003751', '6300043009', '6300042985', '7360014117', '7360014109', '7400016053', 
     '7400016254', '7460064345', '7460064353', '7710018651', '8360031658', '8360031754', '8450027618', '8450027675', 
     '9130005852', '9130005878', 
    );
$invalid_samples = array('4780040913', '7700040832', '7700040828', '7710018660', '0680066806', '1670068624',);

echo "<pre>";
echo "valid number test: <br>";
foreach($valid_samples as $vkno){
    $check = vergiKimlikDogrulama($vkno);
    echo "number: ".$vkno." test result: ".var_export($check,1)."<br>";
}


echo "<br>invalid number test: <br>";
foreach($invalid_samples as $vkno){
    $check = vergiKimlikDogrulama($vkno);
    echo "number: ".$vkno." test result: ".var_export($check,1)."<br>";
}