//! Stop a world child after a deadline. Expiration returns status 124.
use sausage_spawn::Command;
use std::time::{Duration, Instant};
fn run() -> Result<i32, Box<dyn std::error::Error>> {
    let mut args = std::env::args().skip(1);
    let duration = args.next().ok_or("a duration is required")?;
    let (number, multiplier) = match duration.as_bytes().last() {
        Some(b's') => (&duration[..duration.len()-1], 1.0),
        Some(b'm') => (&duration[..duration.len()-1], 60.0),
        Some(b'h') => (&duration[..duration.len()-1], 3600.0),
        Some(b'd') => (&duration[..duration.len()-1], 86400.0),
        _ => (&duration[..], 1.0),
    };
    let duration = Duration::try_from_secs_f64(number.parse::<f64>()? * multiplier)?;
    let program = args.next().ok_or("a command is required")?;
    let child = Command::new(program).args(args).new_group().spawn()?;
    if duration.is_zero() { return Ok(child.wait()); }
    let deadline = Instant::now() + duration;
    loop {
        if let Some(code) = child.try_wait() { return Ok(code); }
        if Instant::now() >= deadline { child.kill(); child.wait(); return Ok(124); }
        std::thread::sleep(Duration::from_millis(10).min(deadline.saturating_duration_since(Instant::now())));
    }
}
fn main() { std::process::exit(match run() { Ok(code) => code, Err(e) => { eprintln!("timeout: {e}"); 125 } }); }