devpane 0.2.0

use std::{io, mem};

pub fn stop_process(pid: u32) -> Result<bool, io::Error> {
    let pid = pid_to_i32(pid)?;

    let result = unsafe { libc::kill(pid, libc::SIGTERM) };

    if result == 0 {
        return Ok(true);
    }

    let err = io::Error::last_os_error();

    match err.raw_os_error() {
        Some(libc::ESRCH) => Ok(false),
        _ => Err(err),
    }
}

pub fn is_process_active(pid: u32) -> Result<bool, io::Error> {
    let pid = pid_to_i32(pid)?;

    let result = unsafe { libc::kill(pid, 0) };

    if result == 0 {
        return Ok(true);
    }

    let err = io::Error::last_os_error();

    match err.raw_os_error() {
        Some(libc::ESRCH) => Ok(false),
        Some(libc::EPERM) => Ok(true),
        _ => Err(err),
    }
}

pub fn get_process_start_time(pid: u32) -> Result<(u64, u64), io::Error> {
    let pid = pid_to_i32(pid)?;

    let mut info: libc::proc_bsdinfo = unsafe { mem::zeroed() };
    let size = mem::size_of::<libc::proc_bsdinfo>() as i32;

    let result = unsafe {
        libc::proc_pidinfo(
            pid,
            libc::PROC_PIDTBSDINFO,
            0,
            &mut info as *mut _ as *mut libc::c_void,
            size,
        )
    };

    if result <= 0 {
        return Err(io::Error::last_os_error());
    }

    if result < size {
        return Err(io::Error::new(
            io::ErrorKind::InvalidData,
            "short proc_pidinfo result",
        ));
    }

    Ok((info.pbi_start_tvsec, info.pbi_start_tvusec))
}

fn pid_to_i32(pid: u32) -> Result<i32, io::Error> {
    i32::try_from(pid).map_err(|_| io::Error::new(io::ErrorKind::InvalidInput, "pid out of range"))
}