use std::{
    io::{self, Write},
    os::unix::net::UnixStream,
    path::Path,
    process::Command,
};

use crate::read_line;

pub trait BinderArg {
    fn from_u8_bind(b: u8) -> Self;
}

pub struct DynLib {
    stream: UnixStream,
}

impl DynLib {
    pub fn load(dyn_lib: &str) -> io::Result<Self> {
        if !Path::new(&format!("/tmp/{dyn_lib}")).exists() {
            let path = format!("./{dyn_lib}.dyn");
            Command::new(path).spawn().unwrap();
            std::thread::sleep(std::time::Duration::from_millis(100));
        }

        Ok(Self {
            stream: UnixStream::connect(format!("/tmp/{dyn_lib}"))?,
        })
    }

    pub fn call<T: BinderArg>(&mut self, fn_id: u8) -> Option<T> {
        self.stream.write_all(&[fn_id, 255]).ok()?;
        self.stream.flush().ok()?;
        let msg = read_line(&mut self.stream)?;
        Some(T::from_u8_bind(msg[0]))
    }
}

impl BinderArg for () {
    fn from_u8_bind(_: u8) -> Self {}
}