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
38
39
40
41
42
43
44
45
46
47
48
use rand::Rng;
pub fn generate(rng: &mut rand::rngs::ThreadRng) -> String {
let digits: Vec<u8> = (0..rng.gen_range(5..11))
.map(|_| rng.gen_range(0..=9))
.collect();
// weighted sum reversed weights 2,3,4...
let mut sum: i32 = 0;
for (i, &d) in digits.iter().rev().enumerate() {
sum += (i as i32 + 2) * d as i32;
}
let check = (-(sum) % 11).rem_euclid(11);
let check_char = if check == 10 {
'K'
} else {
(b'0' + check as u8) as char
};
let mut s: String = digits.iter().map(|d| (b'0' + d) as char).collect();
s.push(check_char);
s
}
pub fn validate(code: &str) -> bool {
let clean = code
.to_uppercase()
.replace([' ', '-'], "")
.trim_start_matches('0')
.to_string();
if clean.len() < 2 || clean.len() > 12 {
return false;
}
if !clean[..clean.len() - 1].chars().all(|c| c.is_ascii_digit()) {
return false;
}
let digits: Vec<u8> = clean[..clean.len() - 1].bytes().map(|b| b - b'0').collect();
let mut sum: i32 = 0;
for (i, &d) in digits.iter().rev().enumerate() {
sum += (i as i32 + 2) * d as i32;
}
let expected = (-(sum) % 11).rem_euclid(11);
let expected_char = if expected == 10 {
'K'
} else {
(b'0' + expected as u8) as char
};
clean.ends_with(expected_char)
}