use super::TcpListener;
use super::TcpStream;
use futures_core::ready;
use futures_core::stream::Stream;
use std::io;
use std::pin::Pin;
use std::task::{Context, Poll};

/// Stream returned by the `TcpListener::incoming` function representing the
/// stream of sockets received from a listener.
#[must_use = "streams do nothing unless polled"]
#[derive(Debug)]
pub struct Incoming {
    inner: TcpListener,
}

impl Incoming {
    pub(crate) fn new(listener: TcpListener) -> Incoming {
        Incoming { inner: listener }
    }
}

impl Stream for Incoming {
    type Item = io::Result<TcpStream>;

    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
        let (socket, _) = ready!(self.inner.poll_accept(cx))?;
        Poll::Ready(Some(Ok(socket)))
    }
}