use nix::{
    unistd::{
        getppid,
        setsid,
        fork,
        ForkResult,
        close as fdclose,
        chdir
    },
    sys::signal::{
        signal,
        Signal,
        SigHandler
    }
};
use std::process::exit;

pub trait OneOrMany<T> {
    fn into_vec(self) -> Vec<T>;
}

impl<T> OneOrMany<T> for T {
    fn into_vec(self) -> Vec<T> {
        vec![self]
    }
}

impl<T> OneOrMany<T> for Vec<T> {
    fn into_vec(self) -> Vec<T> {
        self
    }
}

pub fn daemonize() {
    if getppid().as_raw() != 1 {
        setsig(Signal::SIGTTOU, SigHandler::SigIgn);
        setsig(Signal::SIGTTIN, SigHandler::SigIgn);
        setsig(Signal::SIGTSTP, SigHandler::SigIgn);
    }
    for fd in 0..=2 {
        match fdclose(fd) { _ => () }
    }
    match chdir("/") { _ => () };

    match fork() {
        Ok(ForkResult::Parent {..}) => {
            exit(0);
        },
        Ok(ForkResult::Child) => {
            match setsid() { _ => () }
        }
        Err(_) => {
            exit(255)
        }
    }
}

pub fn setsig(sig: Signal, hnd: SigHandler) {
    unsafe {
        signal(sig, hnd).unwrap();
    }
}

pub fn vec_to_string(v: &[u8]) -> String {
    String::from_utf8_lossy(v).to_string()
}