wip: Fetching diagnostics, parsing notifications.

1 files changed, 189 insertions, 0 deletions

diff --git a/helix-lsp/src/transport.rs b/helix-lsp/src/transport.rs
new file mode 100644
index 00000000..c44ffa91
--- /dev/null
+++ b/helix-lsp/src/transport.rs
@@ -0,0 +1,189 @@
+use std::collections::HashMap;
+
+use crate::{Message, Notification};
+
+use jsonrpc_core as jsonrpc;
+use lsp_types as lsp;
+use serde_json::Value;
+
+use smol::prelude::*;
+
+use smol::{
+    channel::{Receiver, Sender},
+    io::{BufReader, BufWriter},
+    process::{ChildStderr, ChildStdin, ChildStdout},
+    Executor,
+};
+
+pub(crate) enum Payload {
+    Request {
+        chan: Sender<anyhow::Result<Value>>,
+        value: jsonrpc::MethodCall,
+    },
+    Notification(jsonrpc::Notification),
+}
+
+pub(crate) struct Transport {
+    incoming: Sender<Message>,
+    outgoing: Receiver<Payload>,
+
+    pending_requests: HashMap<jsonrpc::Id, Sender<anyhow::Result<Value>>>,
+    headers: HashMap<String, String>,
+
+    writer: BufWriter<ChildStdin>,
+    reader: BufReader<ChildStdout>,
+}
+
+impl Transport {
+    pub fn start(
+        ex: &Executor,
+        reader: BufReader<ChildStdout>,
+        writer: BufWriter<ChildStdin>,
+    ) -> (Receiver<Message>, Sender<Payload>) {
+        let (incoming, rx) = smol::channel::unbounded();
+        let (tx, outgoing) = smol::channel::unbounded();
+
+        let transport = Self {
+            reader,
+            writer,
+            incoming,
+            outgoing,
+            pending_requests: Default::default(),
+            headers: Default::default(),
+        };
+
+        ex.spawn(transport.duplex()).detach();
+
+        (rx, tx)
+    }
+
+    async fn recv(
+        reader: &mut (impl AsyncBufRead + Unpin),
+        headers: &mut HashMap<String, String>,
+    ) -> Result<Message, std::io::Error> {
+        // read headers
+        loop {
+            let mut header = String::new();
+            // detect pipe closed if 0
+            reader.read_line(&mut header).await?;
+            let header = header.trim();
+
+            if header.is_empty() {
+                break;
+            }
+
+            let parts: Vec<&str> = header.split(": ").collect();
+            if parts.len() != 2 {
+                // return Err(Error::new(ErrorKind::Other, "Failed to parse header"));
+                panic!()
+            }
+            headers.insert(parts[0].to_string(), parts[1].to_string());
+        }
+
+        // find content-length
+        let content_length = headers.get("Content-Length").unwrap().parse().unwrap();
+
+        let mut content = vec![0; content_length];
+        reader.read_exact(&mut content).await?;
+        let msg = String::from_utf8(content).unwrap();
+
+        // read data
+
+        // try parsing as output (server response) or call (server request)
+        let output: serde_json::Result<Message> = serde_json::from_str(&msg);
+
+        Ok(output?)
+    }
+
+    pub async fn send_payload(&mut self, payload: Payload) -> anyhow::Result<()> {
+        match payload {
+            Payload::Request { chan, value } => {
+                self.pending_requests.insert(value.id.clone(), chan);
+
+                let json = serde_json::to_string(&value)?;
+                self.send(json).await
+            }
+            Payload::Notification(value) => {
+                let json = serde_json::to_string(&value)?;
+                self.send(json).await
+            }
+        }
+    }
+
+    pub async fn send(&mut self, request: String) -> anyhow::Result<()> {
+        println!("-> {}", request);
+
+        // send the headers
+        self.writer
+            .write_all(format!("Content-Length: {}\r\n\r\n", request.len()).as_bytes())
+            .await?;
+
+        // send the body
+        self.writer.write_all(request.as_bytes()).await?;
+
+        self.writer.flush().await?;
+
+        Ok(())
+    }
+
+    pub async fn recv_msg(&mut self, msg: Message) -> anyhow::Result<()> {
+        match msg {
+            Message::Output(output) => self.recv_response(output).await?,
+            Message::Notification(jsonrpc::Notification { method, params, .. }) => {
+                let notification = Notification::parse(&method, params);
+
+                println!("<- {} {:?}", method, notification);
+                // dispatch
+            }
+            Message::Call(call) => {
+                println!("<- {:?}", call);
+                // dispatch
+            }
+            _ => unreachable!(),
+        };
+        Ok(())
+    }
+
+    pub async fn recv_response(&mut self, output: jsonrpc::Output) -> anyhow::Result<()> {
+        match output {
+            jsonrpc::Output::Success(jsonrpc::Success { id, result, .. }) => {
+                println!("<- {}", result);
+
+                let tx = self
+                    .pending_requests
+                    .remove(&id)
+                    .expect("pending_request with id not found!");
+                tx.send(Ok(result)).await?;
+            }
+            jsonrpc::Output::Failure(_) => panic!("recv fail"),
+            msg => unimplemented!("{:?}", msg),
+        }
+        Ok(())
+    }
+
+    pub async fn duplex(mut self) {
+        use futures_util::{select, FutureExt};
+        loop {
+            select! {
+                // client -> server
+                msg = self.outgoing.next().fuse() => {
+                    if msg.is_none() {
+                        break;
+                    }
+                    let msg = msg.unwrap();
+
+                    self.send_payload(msg).await.unwrap();
+                }
+                // server <- client
+                msg = Self::recv(&mut self.reader, &mut self.headers).fuse() => {
+                    if msg.is_err() {
+                        break;
+                    }
+                    let msg = msg.unwrap();
+
+                    self.recv_msg(msg).await.unwrap();
+                }
+            }
+        }
+    }
+}