1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
use rand::Rng;
pub fn generate(rng: &mut rand::rngs::ThreadRng) -> String {
let mut digits: Vec<u8> = (0..8).map(|_| rng.gen_range(0..=9)).collect();
let mut checksum = 0;
for &d in &digits {
checksum = checksum * 2 + d as u32;
}
let check = (checksum * 2 % 11) % 10;
digits.push(check as u8);
digits.iter().map(|d| (b'0' + d) as char).collect()
}
pub fn validate(code: &str) -> bool {
let clean: String = if let Some(stripped) = code.strip_prefix("EL") {
stripped.to_string()
} else if let Some(stripped) = code.strip_prefix("GR") {
stripped.to_string()
} else {
code.chars().filter(|c| c.is_ascii_digit()).collect()
};
let clean = if clean.len() == 8 {
format!("0{}", clean)
} else {
clean
};
if clean.len() != 9 || !clean.chars().all(|c| c.is_ascii_digit()) {
return false;
}
let digits: Vec<u8> = clean.bytes().map(|b| b - b'0').collect();
let mut checksum = 0;
for &d in &digits[..8] {
checksum = checksum * 2 + d as u32;
}
let expected = (checksum * 2 % 11) % 10;
expected == digits[8] as u32
}