use super::ClientAgent;

use warp::ws::WebSocket;
use futures::{future::Future, stream::Stream, Async};
use log;
use std::time::{Duration, Instant};

pub struct EventStream;

impl EventStream {


/// Send a stream of replies to a WebSocket client.
    pub fn to_ws(
    socket: WebSocket,
    mut client_agent: ClientAgent,
    update_interval: Duration,
) -> impl Future<Item = (), Error = ()> {
    let (ws_tx, mut ws_rx) = socket.split();
    let timeline = client_agent.subscription.timeline;

    // Create a pipe
    let (tx, rx) = futures::sync::mpsc::unbounded();

    // Send one end of it to a different thread and tell that end to forward whatever it gets
    // on to the websocket client
    warp::spawn(
        rx.map_err(|()| -> warp::Error { unreachable!() })
            .forward(ws_tx)
            .map(|_r| ())
            .map_err(|e| match e.to_string().as_ref() {
                "IO error: Broken pipe (os error 32)" => (), // just closed unix socket
                _ => log::warn!("websocket send error: {}", e),
            }),
    );

    // Yield new events for as long as the client is still connected
    let event_stream = tokio::timer::Interval::new(Instant::now(), update_interval).take_while(
        move |_| match ws_rx.poll() {
            Ok(Async::NotReady) | Ok(Async::Ready(Some(_))) => futures::future::ok(true),
            Ok(Async::Ready(None)) => {
                // TODO: consider whether we should manually drop closed connections here
                log::info!("Client closed WebSocket connection for {:?}", timeline);
                futures::future::ok(false)
            }
            Err(e) if e.to_string() == "IO error: Broken pipe (os error 32)" => {
                // no err, just closed Unix socket
                log::info!("Client closed WebSocket connection for {:?}", timeline);
                futures::future::ok(false)
            }
            Err(e) => {
                log::warn!("Error in {:?}: {}", timeline, e);
                futures::future::ok(false)
            }
        },
    );

    let mut time = Instant::now();
    // Every time you get an event from that stream, send it through the pipe
    event_stream
        .for_each(move |_instant| {
            if let Ok(Async::Ready(Some(msg))) = client_agent.poll() {
                tx.unbounded_send(warp::ws::Message::text(msg.to_json_string()))
                    .expect("No send error");
            };
            if time.elapsed() > Duration::from_secs(30) {
                tx.unbounded_send(warp::ws::Message::text("{}"))
                    .expect("Can ping");
                time = Instant::now();
            }
            Ok(())
        })
        .then(move |result| {
            // TODO: consider whether we should manually drop closed connections here
            log::info!("WebSocket connection for {:?} closed.", timeline);
            result
        })
        .map_err(move |e| log::warn!("Error sending to {:?}: {}", timeline, e))
}
    pub fn to_sse(
    mut client_agent: ClientAgent,
    connection: warp::sse::Sse,
    update_interval: Duration,
) ->impl warp::reply::Reply {
    let event_stream =
        tokio::timer::Interval::new(Instant::now(), update_interval).filter_map(move |_| {
            match client_agent.poll() {
                Ok(Async::Ready(Some(event))) => Some((
                    warp::sse::event(event.event_name()),
                    warp::sse::data(event.payload().unwrap_or_else(String::new)),
                )),
                _ => None,
            }
        });

    connection.reply(
        warp::sse::keep_alive()
            .interval(Duration::from_secs(30))
            .text("thump".to_string())
            .stream(event_stream),
    )
}
}