use std::marker::Unpin;

use std::pin::Pin;

use std::task::{ready, Poll};

use hyper::rt::{Read, ReadBuf, Write};

use std::future::poll_fn;

pub(crate) async fn read<T>(io: &mut T, buf: &mut [u8]) -> Result<usize, std::io::Error>

where

    T: Read + Unpin,

{

    poll_fn(move |cx| {

        let mut buf = ReadBuf::new(buf);

        ready!(Pin::new(&mut *io).poll_read(cx, buf.unfilled()))?;

        Poll::Ready(Ok(buf.filled().len()))

    })

    .await

}

pub(crate) async fn write_all<T>(io: &mut T, buf: &[u8]) -> Result<(), std::io::Error>

where

    T: Write + Unpin,

{

    let mut n = 0;

    poll_fn(move |cx| {

        while n < buf.len() {

            n += ready!(Pin::new(&mut *io).poll_write(cx, &buf[n..])?);

        }

        Poll::Ready(Ok(()))

    })

    .await

}