From af5c09060045c53bb785217dd9f40c1f7132348c Mon Sep 17 00:00:00 2001
From: soruh <mail@soruh.de>
Date: Sun, 11 Jun 2023 02:40:39 +0200
Subject: [PATCH] refactors

---
 src/http.rs | 175 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 src/http.rs

diff --git a/src/http.rs b/src/http.rs
new file mode 100644
index 0000000..50024e2
--- /dev/null
+++ b/src/http.rs
@@ -0,0 +1,175 @@
+use futures::Future;
+use tokio_stream::StreamExt;
+
+use hyper::rt::Executor;
+use hyper::service::{make_service_fn, service_fn};
+use hyper::{Body, Method, Response, Server, StatusCode};
+use std::convert::Infallible;
+use std::net::SocketAddr;
+use std::sync::Arc;
+use std::time::{SystemTime, UNIX_EPOCH};
+use tokio::sync::Mutex;
+use tokio_stream::wrappers::{IntervalStream, WatchStream};
+use tracing::error;
+
+use zerocopy::{AsBytes, FromBytes, LittleEndian, Unaligned};
+
+use tracing::{debug, instrument};
+
+use crate::constants::DEBUG_SERVER_PING_INTERVAL;
+use crate::packets::{Header, Packet};
+
+use crate::ports::PortHandler;
+use crate::spawn;
+
+#[derive(Clone)]
+struct NamedExecutor;
+impl<T: Send + 'static, Fut: Future<Output = T> + Send + 'static> Executor<Fut> for NamedExecutor {
+    fn execute(&self, fut: Fut) {
+        spawn("http worker", fut);
+    }
+}
+
+pub async fn debug_server(
+    addr: SocketAddr,
+    port_handler: Arc<Mutex<PortHandler>>,
+    change_receiver: tokio::sync::watch::Receiver<std::time::Instant>,
+) {
+    let server = Server::bind(&addr)
+        .executor(NamedExecutor)
+        .serve(make_service_fn(move |_conn| {
+            let port_handler = port_handler.clone();
+            let change_receiver = change_receiver.clone();
+            async move {
+                Ok::<_, Infallible>(service_fn(move |req| {
+                    let port_handler = port_handler.clone();
+                    let change_receiver = WatchStream::new(change_receiver.clone());
+                    async move {
+                        match (req.method(), req.uri().path()) {
+                            (&Method::GET, "/") => Ok(Response::new(Body::from(include_str!(
+                                concat!(env!("OUT_DIR"), "/minified.html")
+                            )))),
+
+                            (&Method::GET, "/data") => {
+                                let res = Response::builder().header("Cache-Control", "no-store");
+
+                                match serde_json::to_string(&*port_handler.lock().await) {
+                                    Ok(data) => res
+                                        .header("Content-Type", "application/json")
+                                        .body(Body::from(data)),
+                                    Err(err) => {
+                                        error!(%err, "failed to serialize data for debug server");
+                                        res.status(StatusCode::INTERNAL_SERVER_ERROR)
+                                            .body(Body::from(""))
+                                    }
+                                }
+                            }
+
+                            (&Method::GET, "/events") => Response::builder()
+                                .status(StatusCode::OK)
+                                .header("Cache-Control", "no-store")
+                                .header("Content-Type", "text/event-stream")
+                                .body(Body::wrap_stream({
+                                    change_receiver
+                                        .map(|x| ("change", x))
+                                        .merge(
+                                            IntervalStream::new(tokio::time::interval(
+                                                DEBUG_SERVER_PING_INTERVAL,
+                                            ))
+                                            .map(|x| ("ping", x.into_std())),
+                                        )
+                                        .filter_map(|(kind, time)| {
+                                            let timestamp = (SystemTime::now() + time.elapsed())
+                                                .duration_since(UNIX_EPOCH)
+                                                .ok()?
+                                                .as_secs();
+
+                                            Some(Ok::<_, Infallible>(format!(
+                                                "event:{kind}\ndata: {timestamp}\n\n"
+                                            )))
+                                        })
+                                })),
+                            _ => Response::builder()
+                                .status(StatusCode::NOT_FOUND)
+                                .body(Body::empty()),
+                        }
+                    }
+                }))
+            }
+        }));
+
+    if let Err(error) = server.await {
+        error!(%error, "debug server error");
+    }
+}
+
+type U16 = zerocopy::U16<LittleEndian>;
+type U32 = zerocopy::U32<LittleEndian>;
+
+#[derive(AsBytes)]
+#[repr(transparent)]
+#[allow(dead_code)]
+struct PeerQuery {
+    number: U32,
+}
+
+#[derive(FromBytes, Unaligned, Debug)]
+#[repr(packed)]
+#[allow(dead_code)]
+struct PeerReply {
+    number: U32,
+    name: [u8; 40],
+    flags: U16,
+    kind: u8,
+    hostname: [u8; 40],
+    ipaddress: [u8; 4],
+    port: U16,
+    extension: u8,
+    pin: U16,
+    timestamp: U32,
+}
+
+#[instrument]
+pub async fn peer_query(server: &SocketAddr, number: u32) -> eyre::Result<Option<String>> {
+    debug!(%number, "looking up");
+
+    let mut packet = Packet {
+        header: Header {
+            kind: 3, // Peer Query
+            length: 4,
+        },
+        data: Vec::new(),
+    };
+
+    packet.data.clear();
+    packet.data.resize(packet.header.length as usize, 0);
+
+    PeerQuery {
+        number: number.into(),
+    }
+    .write_to(packet.data.as_mut_slice())
+    .unwrap();
+
+    let mut socket = tokio::net::TcpStream::connect(server).await?;
+
+    let (mut reader, mut writer) = socket.split();
+
+    packet.send(&mut writer).await?;
+    packet.recv_into(&mut reader).await?;
+
+    Ok(if packet.kind().raw() == 5 {
+        // PeerReply
+        PeerReply::read_from(packet.data.as_slice()).and_then(|x| {
+            let i = x
+                .name
+                .iter()
+                .enumerate()
+                .find_map(|(i, c)| (*c == 0).then_some(i))
+                .unwrap_or(x.name.len());
+
+            Some(std::str::from_utf8(&x.name[..i]).ok()?.to_owned())
+        })
+    } else {
+        None
+    })
+}