pub fn short_fp(fp: &str) -> String {
fp.split('-').next().unwrap_or(fp).to_string()
}
pub fn short_fp2(fp: &str) -> String {
fp.split('-').take(2).collect::<Vec<_>>().join("-")
}
pub fn display_id(fp: &str) -> String {
if fp.starts_with("HD-") {
return fp.to_string();
}
let upper = fp.to_ascii_uppercase();
if upper.contains('-') {
return format!("HD-{}", upper);
}
if upper.len() == 24 && upper.chars().all(|c| c.is_ascii_hexdigit()) {
let groups: Vec<String> = upper
.as_bytes()
.chunks(4)
.map(|c| std::str::from_utf8(c).unwrap().to_string())
.collect();
return format!("HD-{}", groups.join("-"));
}
format!("HD-{}", upper)
}
pub fn hhmm(unix: i64) -> String {
let secs = unix.rem_euclid(86_400);
format!("{:02}:{:02}", secs / 3600, (secs % 3600) / 60)
}
pub fn day_bucket(unix: i64) -> i64 {
unix.div_euclid(86_400)
}
pub fn ymd_string(unix: i64) -> String {
let z = unix.div_euclid(86_400) + 719_468;
let era = if z >= 0 { z } else { z - 146_096 } / 146_097;
let doe = z - era * 146_097;
let yoe = (doe - doe / 1460 + doe / 36_524 - doe / 146_096) / 365;
let y = yoe + era * 400;
let doy = doe - (365 * yoe + yoe / 4 - yoe / 100);
let mp = (5 * doy + 2) / 153;
let d = doy - (153 * mp + 2) / 5 + 1;
let m = if mp < 10 { mp + 3 } else { mp - 9 };
let y = if m <= 2 { y + 1 } else { y };
format!("{y:04}-{m:02}-{d:02}")
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn ymd_known_epoch() {
assert_eq!(ymd_string(0), "1970-01-01");
assert_eq!(ymd_string(1_609_459_200), "2021-01-01");
assert_eq!(hhmm(1_609_459_200 + 3 * 3600 + 25 * 60), "03:25");
}
#[test]
fn display_id_groups_bare_hex() {
assert_eq!(
display_id("0123456789abcdef01234567"),
"HD-0123-4567-89AB-CDEF-0123-4567"
);
}
#[test]
fn display_id_passes_through_prefixed() {
assert_eq!(display_id("HD-ABCD"), "HD-ABCD");
}
#[test]
fn display_id_uppercases_dashed() {
assert_eq!(display_id("abcd-ef01"), "HD-ABCD-EF01");
}
#[test]
fn short_fp_takes_first_group() {
assert_eq!(short_fp("abcd-ef01-2345"), "abcd");
assert_eq!(short_fp2("abcd-ef01-2345"), "abcd-ef01");
}
}