//! Tower middleware that applies a timeout to requests.
//!
//! If the response does not complete within the specified timeout, the response
//! will be aborted.

pub mod error;
pub mod future;
mod layer;

pub use self::layer::TimeoutLayer;

use self::future::ResponseFuture;
use std::task::{Context, Poll};
use std::time::Duration;
use tower_service::Service;

/// Applies a timeout to requests.
#[derive(Debug, Clone)]
pub struct Timeout<T> {
    inner: T,
    timeout: Duration,
}

// ===== impl Timeout =====

impl<T> Timeout<T> {
    /// Creates a new Timeout
    pub fn new(inner: T, timeout: Duration) -> Self {
        Timeout { inner, timeout }
    }

    /// Get a reference to the inner service
    pub fn get_ref(&self) -> &T {
        &self.inner
    }

    /// Get a mutable reference to the inner service
    pub fn get_mut(&mut self) -> &mut T {
        &mut self.inner
    }

    /// Consume `self`, returning the inner service
    pub fn into_inner(self) -> T {
        self.inner
    }
}

impl<S, Request> Service<Request> for Timeout<S>
where
    S: Service<Request>,
    S::Error: Into<crate::BoxError>,
{
    type Response = S::Response;
    type Error = crate::BoxError;
    type Future = ResponseFuture<S::Future>;

    fn poll_ready(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        match self.inner.poll_ready(cx) {
            Poll::Pending => Poll::Pending,
            Poll::Ready(r) => Poll::Ready(r.map_err(Into::into)),
        }
    }

    fn call(&mut self, request: Request) -> Self::Future {
        let response = self.inner.call(request);
        let sleep = tokio::time::sleep(self.timeout);

        ResponseFuture::new(response, sleep)
    }
}