#![forbid(unsafe_code)]
// #![warn(missing_docs)]

pub mod body;
mod redirect;
mod request;
pub mod response;
mod result_ext;
pub mod route;

use std::convert::{Infallible, TryFrom};
use std::future::Future;
use std::pin::Pin;
use std::task::{Context, Poll};

pub use body::Body;
use headers::HeaderMapExt;
use http_body::Body as _;
pub use http_body_util::{BodyExt, Full};
pub use hyper::body::Bytes;
use hyper::body::Incoming;
use hyper::service::Service;
use hyper_util::rt::TokioExecutor;
use hyper_util::server::conn::auto;
use hyper_util::service::TowerToHyperService;
pub use redirect::Redirect;
pub use request::{DecodeQueryError, Request, RequestExt};
pub use response::{IntoResponse, Response};
pub use result_ext::ResultExt;
pub use {http, hyper};

#[derive(Clone)]
pub struct SolarSail<S, H> {
    state: S,
    handler: H,
}

impl<S, H> SolarSail<S, H> {
    pub fn new(state: S, handler: H) -> Self {
        SolarSail { state, handler }
    }

    async fn serve<F>(&self, req: Request) -> Response
    where
        S: Clone,
        H: Fn(S, Request) -> F,
        F: Future<Output = Response>,
    {
        (self.handler)(self.state.clone(), req)
            .await
            .into_response()
    }

    pub async fn run<F>(
        self,
        addr: &std::net::SocketAddr,
    ) -> Result<(), Box<dyn std::error::Error + Send + Sync>>
    where
        S: Clone + Send + Sync + 'static,
        H: Fn(S, Request) -> F + Clone + Send + Sync + 'static,
        F: Future<Output = Response> + Send + 'static,
    {
        use hyper_util::rt::TokioIo;
        use tokio::net::TcpListener;

        let listener = TcpListener::bind(addr).await?;
        println!("Listening on http://{}", addr);
        loop {
            let (stream, _) = listener.accept().await?;
            let service = self.clone();
            tokio::task::spawn(async move {
                if let Err(err) = auto::Builder::new(TokioExecutor::new())
                    .serve_connection(TokioIo::new(stream), service)
                    .await
                {
                    // Ignore certain network errors
                    if let Some(err) = err.downcast_ref::<hyper::Error>() {
                        if err.is_incomplete_message() {
                            return;
                        }
                    }

                    #[cfg(not(feature = "tracing"))]
                    let _ = err;

                    #[cfg(feature = "tracing")]
                    tracing::error!(%err, "error serving connection");
                }
            });
        }
    }

    pub async fn run_in<F, L, B>(
        self,
        addr: &std::net::SocketAddr,
        layer: L,
    ) -> Result<(), Box<dyn std::error::Error + Send + Sync>>
    where
        S: Clone + Send + Sync + 'static,
        H: Fn(S, Request) -> F + Clone + Send + Sync + 'static,
        F: Future<Output = Response> + Send + 'static,
        L: tower_layer::Layer<Self>,
        L::Service: tower_service::Service<http::Request<Incoming>, Response = http::Response<B>>
            + Clone
            + Send
            + Sync
            + 'static,
        <L::Service as tower_service::Service<http::Request<Incoming>>>::Future: Send,
        <L::Service as tower_service::Service<http::Request<Incoming>>>::Error:
            std::error::Error + Send + Sync,
        B: http_body::Body + Send + 'static,
        B::Data: Send,
        B::Error: Into<Box<dyn std::error::Error + Send + Sync>> + Send + Sync,
    {
        use hyper_util::rt::TokioIo;
        use tokio::net::TcpListener;

        let svc = TowerToHyperService::new(layer.layer(self));
        let listener = TcpListener::bind(addr).await?;
        println!("Listening on http://{}", addr);
        loop {
            let (stream, _) = listener.accept().await?;
            let svc = svc.clone();
            tokio::task::spawn(async move {
                if let Err(err) = auto::Builder::new(TokioExecutor::new())
                    .serve_connection(TokioIo::new(stream), svc)
                    .await
                {
                    // Ignore certain network errors
                    if let Some(err) = err.downcast_ref::<hyper::Error>() {
                        if err.is_incomplete_message() {
                            return;
                        }
                    }

                    #[cfg(not(feature = "tracing"))]
                    let _ = err;

                    #[cfg(feature = "tracing")]
                    tracing::error!(%err, "error serving connection");
                }
            });
        }
    }
}

type BoxTrySendFuture<R, E> = Pin<Box<dyn Future<Output = Result<R, E>> + Send>>;

impl<S, H, F> Service<http::Request<Incoming>> for SolarSail<S, H>
where
    S: Clone + Send + Sync + 'static,
    H: Fn(S, Request) -> F + Clone + Send + Sync + 'static,
    F: Future<Output = Response> + Send + 'static,
{
    type Response = Response;
    type Error = Infallible;
    // TODO: get rid of Box?
    type Future = BoxTrySendFuture<Self::Response, Self::Error>;

    fn call(&self, req: http::Request<Incoming>) -> Self::Future {
        let (parts, body) = req.into_parts();
        let body = if body.is_end_stream() {
            body::Body::empty()
        } else {
            body::Body::new(
                body,
                parts
                    .headers
                    .typed_get()
                    .map(|h: headers::ContentLength| usize::try_from(h.0).unwrap_or(usize::MAX)),
                parts.headers.get(http::header::CONTENT_TYPE).cloned(),
            )
        };

        let svc = self.clone();
        let req = Request::from_parts(parts, body);
        Box::pin(async move { Ok(svc.serve(req).await) })
    }
}

impl<S, H, F> tower_service::Service<http::Request<Incoming>> for SolarSail<S, H>
where
    S: Clone + Send + Sync + 'static,
    H: Fn(S, Request) -> F + Clone + Send + Sync + 'static,
    F: Future<Output = Response> + Send + 'static,
{
    type Response = Response;
    type Error = Infallible;
    // TODO: get rid of Box?
    type Future = BoxTrySendFuture<Self::Response, Self::Error>;

    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
        Poll::Ready(Ok(()))
    }

    fn call(&mut self, req: http::Request<Incoming>) -> Self::Future {
        Service::call(&*self, req)
    }
}