use support::*;

use bytes::BytesMut;
use linkerd2_proxy_api::tap as pb;

pub fn client(addr: SocketAddr) -> Client {
    let api = pb::client::Tap::new(SyncSvc(client::http2(addr, "localhost")));
    Client {
        api,
    }
}

pub struct Client {
    api: pb::client::Tap<SyncSvc>,
}

impl Client {
    pub fn observe(&mut self, req: ObserveBuilder) -> impl Stream<Item = pb::TapEvent, Error = tower_grpc::Error> {
        let req = tower_grpc::Request::new(req.0);
        self.api.observe(req)
            .wait()
            .expect("tap observe wait")
            .into_inner()
    }
}

pub fn observe_request() -> ObserveBuilder {
    ObserveBuilder(pb::ObserveRequest {
        limit: 100,
        match_: Some(pb::observe_request::Match {
            match_: Some(pb::observe_request::match_::Match::Http(
                pb::observe_request::match_::Http {
                    match_: Some(pb::observe_request::match_::http::Match::Path(
                        pb::observe_request::match_::http::StringMatch {
                            match_: Some(pb::observe_request::match_::http::string_match::Match::Prefix(
                                "/".to_string()
                            )),
                        },
                    )),
                },
            )),
        }),
    })
}

#[derive(Debug)]
pub struct ObserveBuilder(pb::ObserveRequest);

impl ObserveBuilder {
    pub fn limit(mut self, limit: u32) -> Self {
        self.0.limit = limit;
        self
    }

    pub fn ports(mut self, min: u16, max: u16) -> Self {
        self.0.match_ = Some(pb::observe_request::Match {
            match_: Some(
                pb::observe_request::match_::Match::Destination(
                    pb::observe_request::match_::Tcp {
                        match_: Some(pb::observe_request::match_::tcp::Match::Ports(
                            pb::observe_request::match_::tcp::PortRange {
                                min: min.into(),
                                max: max.into(),
                            },
                        )),
                    },
                ),
            ),
        });
        self
    }
}

pub trait TapEventExt {
    fn is_inbound(&self) -> bool;
    fn is_outbound(&self) -> bool;
    //fn id(&self) -> (u32, u64);
    fn event(&self) -> &pb::tap_event::http::Event;

    fn request_init_method(&self) -> String;
    fn request_init_authority(&self) -> &str;
    fn request_init_path(&self) -> &str;

    fn response_init_status(&self) -> u16;

    fn response_end_bytes(&self) -> u64;
    fn response_end_eos_grpc(&self) -> u32;
}

impl TapEventExt for pb::TapEvent {
    fn is_inbound(&self) -> bool {
        self.proxy_direction == pb::tap_event::ProxyDirection::Inbound as i32
    }

    fn is_outbound(&self) -> bool {
        self.proxy_direction == pb::tap_event::ProxyDirection::Outbound as i32
    }

    fn event(&self) -> &pb::tap_event::http::Event {
        match self.event {
            Some(
                pb::tap_event::Event::Http(
                    pb::tap_event::Http {
                        event: Some(ref ev),
                    }
                )
            ) => ev,
            _ => panic!("unknown event: {:?}", self.event),
        }
    }

    fn request_init_method(&self) -> String {
        match self.event() {
            pb::tap_event::http::Event::RequestInit(_ev) => {
                //TODO: ugh
                unimplemented!("method");
            },
            _ => panic!("not RequestInit event"),
        }
    }

    fn request_init_authority(&self) -> &str {
        match self.event() {
            pb::tap_event::http::Event::RequestInit(ev) => {
                &ev.authority
            },
            _ => panic!("not RequestInit event"),
        }
    }

    fn request_init_path(&self) -> &str {
        match self.event() {
            pb::tap_event::http::Event::RequestInit(ev) => {
                &ev.path
            },
            _ => panic!("not RequestInit event"),
        }
    }

    fn response_init_status(&self) -> u16 {
        match self.event() {
            pb::tap_event::http::Event::ResponseInit(ev) => {
                ev.http_status as u16
            },
            _ => panic!("not ResponseInit event"),
        }
    }

    fn response_end_bytes(&self) -> u64 {
        match self.event() {
            pb::tap_event::http::Event::ResponseEnd(ev) => {
                ev.response_bytes
            },
            _ => panic!("not ResponseEnd event"),
        }
    }

    fn response_end_eos_grpc(&self) -> u32 {
        match self.event() {
            pb::tap_event::http::Event::ResponseEnd(ev) => {
                match ev.eos {
                    Some(pb::Eos {
                        end: Some(pb::eos::End::GrpcStatusCode(code)),
                    }) => code,
                    _ => panic!("not Eos GrpcStatusCode: {:?}", ev.eos),
                }
            },
            _ => panic!("not ResponseEnd event"),
        }
    }
}

struct SyncSvc(client::Client);

impl<B> tower_service::Service<http::Request<B>> for SyncSvc
where
    B: tower_grpc::Body<Data = Bytes>,
{
    type Response = http::Response<GrpcBody>;
    type Error = String;
    type Future = Box<Future<Item = Self::Response, Error = Self::Error> + Send>;

    fn poll_ready(&mut self) -> Poll<(), Self::Error> {
        unreachable!("tap SyncSvc poll_ready");
    }

    fn call(&mut self, req: http::Request<B>) -> Self::Future {
        let req = req.map(|mut body| {
            let mut buf = BytesMut::new();
            while let Some(bytes) = future::poll_fn(|| body.poll_data()).wait().expect("req body") {
                buf.extend_from_slice(&bytes);
            }

            buf.freeze()
        });
        Box::new(self.0.request_body_async(req)
            .map(|res| res.map(GrpcBody)))
    }
}

struct GrpcBody(client::BytesBody);

impl tower_grpc::Body for GrpcBody {
    type Data = Bytes;

    fn poll_data(&mut self) -> Poll<Option<Self::Data>, tower_grpc::Error> {
        self.0.poll_data().map_err(|err| {
            unimplemented!("grpc poll_data error: {}", err)
        })
    }

    fn poll_metadata(&mut self) -> Poll<Option<http::HeaderMap>, tower_grpc::Error> {
        self.0.poll_trailers().map_err(|err| {
            unimplemented!("grpc poll_trailers error: {}", err)
        })
    }
}