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use std::time::Duration;
use crate::display::Quotable;
pub fn from_str(string: &str) -> Result<Duration, String> {
let len = string.len();
if len == 0 {
return Err("empty string".to_owned());
}
let slice = &string[..len - 1];
let (numstr, times) = match string.chars().next_back().unwrap() {
's' => (slice, 1),
'm' => (slice, 60),
'h' => (slice, 60 * 60),
'd' => (slice, 60 * 60 * 24),
val if !val.is_alphabetic() => (string, 1),
_ => {
if string == "inf" || string == "infinity" {
("inf", 1)
} else {
return Err(format!("invalid time interval {}", string.quote()));
}
}
};
let num = numstr
.parse::<f64>()
.map_err(|e| format!("invalid time interval {}: {}", string.quote(), e))?;
if num < 0. {
return Err(format!("invalid time interval {}", string.quote()));
}
const NANOS_PER_SEC: u32 = 1_000_000_000;
let whole_secs = num.trunc();
let nanos = (num.fract() * (NANOS_PER_SEC as f64)).trunc();
let duration = Duration::new(whole_secs as u64, nanos as u32);
Ok(duration.saturating_mul(times))
}
#[cfg(test)]
mod tests {
use crate::parse_time::from_str;
use std::time::Duration;
#[test]
fn test_no_units() {
assert_eq!(from_str("123"), Ok(Duration::from_secs(123)));
}
#[test]
fn test_units() {
assert_eq!(from_str("2d"), Ok(Duration::from_secs(60 * 60 * 24 * 2)));
}
#[test]
fn test_saturating_mul() {
assert_eq!(from_str("9223372036854775808d"), Ok(Duration::MAX));
}
#[test]
fn test_error_empty() {
assert!(from_str("").is_err());
}
#[test]
fn test_error_invalid_unit() {
assert!(from_str("123X").is_err());
}
#[test]
fn test_error_invalid_magnitude() {
assert!(from_str("12abc3s").is_err());
}
#[test]
fn test_negative() {
assert!(from_str("-1").is_err());
}
#[test]
fn test_no_capital_letters() {
assert!(from_str("1S").is_err());
assert!(from_str("1M").is_err());
assert!(from_str("1H").is_err());
assert!(from_str("1D").is_err());
}
}