use futures::{Future, Poll};
use std::io;
use tokio_io::io::{write_all, WriteAll};
use tokio_io::AsyncWrite;
use zebra_message::Message;

pub fn write_message<M, A>(a: A, message: Message<M>) -> WriteMessage<M, A>
where
    A: AsyncWrite,
{
    WriteMessage {
        future: write_all(a, message),
    }
}

pub struct WriteMessage<M, A> {
    future: WriteAll<A, Message<M>>,
}

impl<M, A> Future for WriteMessage<M, A>
where
    A: AsyncWrite,
{
    type Item = (A, Message<M>);
    type Error = io::Error;

    fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
        self.future.poll()
    }
}