use crate::service::routing::Route;
use crate::service::{Layer, Service};
use futures_util::ready;
use http::header::HeaderName;
use http::{HeaderValue, Request, Response};
use pin_project::pin_project;
use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};
#[allow(clippy::declare_interior_mutable_const)]
const DEPRECATION: HeaderName = HeaderName::from_static("deprecation");
#[allow(clippy::declare_interior_mutable_const)]
const IS_DEPRECATED: HeaderValue = HeaderValue::from_static("true");
pub struct DeprecationHeaderLayer;
impl<S> Layer<S> for DeprecationHeaderLayer {
type Service = DeprecationHeaderService<S>;
fn layer(self, inner: S) -> Self::Service {
DeprecationHeaderService { inner }
}
}
pub struct DeprecationHeaderService<S> {
inner: S,
}
impl<S, B1, B2> Service<Request<B1>> for DeprecationHeaderService<S>
where
S: Service<Request<B1>, Response = Response<B2>> + Sync,
B1: Send,
{
type Response = S::Response;
async fn call(&self, req: Request<B1>) -> Self::Response {
let route = req
.extensions()
.get::<Route>()
.expect("Route missing from request extensions");
let deprecated = match route {
Route::Resolved(endpoint) => endpoint.deprecated().is_some(),
_ => false,
};
let mut response = self.inner.call(req).await;
if deprecated {
response.headers_mut().insert(DEPRECATION, IS_DEPRECATED);
}
response
}
}
#[pin_project]
pub struct DeprecationHeaderFuture<F> {
#[pin]
inner: F,
deprecated: bool,
}
impl<F, B> Future for DeprecationHeaderFuture<F>
where
F: Future<Output = Response<B>>,
{
type Output = Response<B>;
fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
let this = self.project();
let mut response = ready!(this.inner.poll(cx));
if *this.deprecated {
response.headers_mut().insert(DEPRECATION, IS_DEPRECATED);
}
Poll::Ready(response)
}
}