use super::Inner;
use tokio_threadpool as threadpool;

use std::fmt;

use futures::{Future, Poll};

/// A future that resolves when the Tokio `Runtime` is shut down.
pub struct Shutdown {
    pub(super) inner: threadpool::Shutdown,
}

impl Shutdown {
    pub(super) fn shutdown_now(inner: Inner) -> Self {
        let inner = inner.pool.shutdown_now();
        Shutdown { inner }
    }
}

impl Future for Shutdown {
    type Item = ();
    type Error = ();

    fn poll(&mut self) -> Poll<(), ()> {
        try_ready!(self.inner.poll());
        Ok(().into())
    }
}

impl fmt::Debug for Shutdown {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.debug_struct("Shutdown")
            .field("inner", &"Box<Future<Item = (), Error = ()>>")
            .finish()
    }
}