function validCodeMeli()
{
do {
$randomNumber = str_pad(mt_rand(1, 99999999), 8, '0', STR_PAD_LEFT);
$code = '0000' . $randomNumber;
$code = substr($code, strlen($code) - 10, 10);

if (intval(substr($code, 3, 6)) == 0) {
continue;
}

$checksum = intval(substr($code, 9, 1));
$s = 0;
for ($i = 0; $i < 9; $i++) {
$s += intval(substr($code, $i, 1)) * (10 - $i);
}

$s = $s % 11;

if (($s < 2 && $checksum == $s) || ($s >= 2 && $checksum == (11 - $s))) {
return $code;
}
} while (true);
}

function validCodeMeli() {
while (true) {
const randomNumber = String(Math.floor(Math.random() * 99999999) + 1).padStart(8, '0');
let code = '0000' + randomNumber;
code = code.slice(code.length - 10);

if (parseInt(code.slice(3, 9), 10) === 0) {
continue;
}

const checksum = parseInt(code.slice(9, 10), 10);
let s = 0;

for (let i = 0; i < 9; i++) {
s += parseInt(code.slice(i, i + 1), 10) * (10 - i);
}

s = s % 11;

if ((s < 2 && checksum === s) || (s >= 2 && checksum === (11 - s))) {
return code;
}
}
}

use rand::Rng;

fn valid_code_meli() -> String {
let mut rng = rand::thread_rng();

loop {
let mut digits = [0u8; 10];

for d in &mut digits[4..] {
*d = rng.gen_range(0..10);
}

let body = &digits[3..9];
if body.iter().all(|&d| d == 0) {
continue;
}

let s: u8 = digits[..9]
.iter()
.enumerate()
.map(|(i, &d)| d * (10 - i as u8))
.sum::<u8>()
% 11;

digits[9] = if s < 2 { s } else { 11 - s };

return digits
.iter()
.map(|d| char::from(b'0' + d))
.collect();
}
}