//! Waits: `sleep <seconds>`. Mostly something to stop with Ctrl+C.

#![no_std]
#![forbid(unsafe_code)]
#![no_main]

extern crate libkos;

use libkos::{println, syscall};
use types::time::Ticks;

/// QEMU virt's timebase.
const TICKS_PER_SECOND: u64 = 10_000_000;

libkos::entry!(main);

fn main() {
    let Some(seconds) = libkos::start::args().nth(1).and_then(|s| s.parse::<u64>().ok()) else {
        println!("usage: sleep <seconds>");
        return;
    };
    let Ok(alarm) = syscall::create_notification() else {
        println!("sleep: no notification");
        return;
    };
    let at = syscall::get_time().raw().saturating_add(seconds.saturating_mul(TICKS_PER_SECOND));
    if syscall::set_timer(alarm, Ticks::from_raw(at)).is_ok() {
        let _ = syscall::wait(alarm);
    }
}