From 35411697791c7149762262f35ed25506991810af Mon Sep 17 00:00:00 2001
From: Radon Rosborough <radon.neon@gmail.com>
Date: Sun, 15 Aug 2021 16:32:09 -0700
Subject: [PATCH] Start and stop LSP

---
 backend/api.js         | 108 ++++++++++++++++++++++++++++-------------
 frontend/pages/app.ejs |   4 +-
 frontend/src/app.js    |  65 +++++++++++++++++++++----
 3 files changed, 130 insertions(+), 47 deletions(-)

diff --git a/backend/api.js b/backend/api.js
index 91d801c..80b26c8 100644
--- a/backend/api.js
+++ b/backend/api.js
@@ -140,40 +140,6 @@ export class Session {
           );
         }
       }
-      if (this.config.lsp) {
-        if (this.config.lsp.setup) {
-          await this.run(this.privilegedExec(this.config.lsp.setup));
-        }
-        const lspArgs = this.privilegedExec(this.config.lsp.start);
-        const lspProc = spawn(lspArgs[0], lspArgs.slice(1));
-        this.lsp = {
-          proc: lspProc,
-          reader: new rpc.StreamMessageReader(lspProc.stdout),
-          writer: new rpc.StreamMessageWriter(lspProc.stdin),
-        };
-        this.lsp.reader.listen((data) => {
-          this.send({ event: "lspOutput", output: data });
-        });
-        lspProc.stderr.on("data", (data) =>
-          this.send({
-            event: "serviceLog",
-            service: "lsp",
-            output: data.toString("utf8"),
-          })
-        );
-        lspProc.on("close", (code, signal) =>
-          this.send({
-            event: "serviceFailed",
-            service: "lsp",
-            error: `Exited with status ${signal || code}`,
-            code: signal || code,
-          })
-        );
-        lspProc.on("error", (err) =>
-          this.send({ event: "serviceFailed", service: "lsp", error: `${err}` })
-        );
-        this.send({ event: "lspStarted", root: this.homedir });
-      }
       this.ws.on("message", (msg) =>
         this.msgQueue.add(() => this.receive(msg))
       );
@@ -256,6 +222,12 @@ export class Session {
           }
           await this.formatCode(msg.code);
           break;
+        case "lspStart":
+          await this.startLSP();
+          break;
+        case "lspStop":
+          await this.stopLSP();
+          break;
         case "lspInput":
           if (typeof msg.input !== "object" || !msg) {
             this.logBadMessage(msg);
@@ -348,7 +320,7 @@ export class Session {
           });
         }
       });
-      this.term.pty.on("exit", (code, signal) => {
+      this.term.pty.on("close", (code, signal) => {
         if (term.live) {
           this.send({
             event: "serviceFailed",
@@ -358,6 +330,15 @@ export class Session {
           });
         }
       });
+      this.term.pty.on("error", (err) => {
+        if (term.live) {
+          this.send({
+            event: "serviceFailed",
+            service: "terminal",
+            error: `${err}`,
+          });
+        }
+      });
     } catch (err) {
       logError(err);
       this.sendError(err);
@@ -431,6 +412,63 @@ export class Session {
     }
   };
 
+  stopLSP = async () => {
+    if (this.lsp) {
+      this.lsp.stopping = true;
+      this.lsp.proc.kill();
+      this.lsp = null;
+    }
+  };
+
+  startLSP = async () => {
+    if (this.config.lsp) {
+      await this.stopLSP();
+      if (this.config.lsp.setup) {
+        await this.run(this.privilegedExec(this.config.lsp.setup));
+      }
+      const lspArgs = this.privilegedExec(this.config.lsp.start);
+      const lspProc = spawn(lspArgs[0], lspArgs.slice(1));
+      const lsp = {
+        proc: lspProc,
+        reader: new rpc.StreamMessageReader(lspProc.stdout),
+        writer: new rpc.StreamMessageWriter(lspProc.stdin),
+        live: true,
+        stopping: false,
+      };
+      this.lsp = lsp;
+      this.lsp.reader.listen((data) => {
+        this.send({ event: "lspOutput", output: data });
+      });
+      lspProc.stderr.on("data", (data) => {
+        if (lsp.live) {
+          this.send({
+            event: "serviceLog",
+            service: "lsp",
+            output: data.toString("utf8"),
+          });
+        }
+      });
+      lspProc.on("close", (code, signal) => {
+        if (lsp.stopping) {
+          this.send({
+            event: "lspStopped",
+          });
+        } else {
+          this.send({
+            event: "serviceFailed",
+            service: "lsp",
+            error: `Exited with status ${signal || code}`,
+            code: signal || code,
+          });
+        }
+      });
+      lspProc.on("error", (err) =>
+        this.send({ event: "serviceFailed", service: "lsp", error: `${err}` })
+      );
+      this.send({ event: "lspStarted", root: this.homedir });
+    }
+  };
+
   ensure = async (cmd) => {
     const code = (
       await this.run(this.privilegedExec(cmd), {
diff --git a/frontend/pages/app.ejs b/frontend/pages/app.ejs
index df459eb..8afa2c5 100644
--- a/frontend/pages/app.ejs
+++ b/frontend/pages/app.ejs
@@ -51,8 +51,8 @@
               <i class="fas fa-code"></i>
             </span>
           </button>
-          <button id="lspButton" type="button" class="button is-small is-warning is-pulled-right is-hidden">
-            <span>Autocomplete OFF</span>
+          <button id="lspButton" type="button" class="button is-small is-warning is-light is-pulled-right is-hidden">
+            <span>Autocomplete <span id="lspButtonState">OFF</span></span>
             <span class="icon is-small">
               <i class="fas fa-bolt"></i>
             </span>
diff --git a/frontend/src/app.js b/frontend/src/app.js
index de9f1d3..a58618d 100644
--- a/frontend/src/app.js
+++ b/frontend/src/app.js
@@ -22,6 +22,8 @@ const DEBUG = window.location.hash === "#debug";
 const config = window.rijuConfig;
 
 const formatButton = document.getElementById("formatButton");
+const lspButton = document.getElementById("lspButton");
+const lspButtonState = document.getElementById("lspButtonState");
 
 function closeModal() {
   document.querySelector("html").classList.remove("is-clipped");
@@ -201,7 +203,25 @@ async function main() {
             editor.setValue(message.code);
           }
           return;
+        case "lspStopped":
+          lspButton.disabled = false;
+          lspButton.classList.remove("is-loading");
+          lspButton.classList.add("is-light");
+          lspButtonState.innerText = "OFF";
+          if (clientDisposable) {
+            clientDisposable.dispose();
+            clientDisposable = null;
+          }
+          if (servicesDisposable) {
+            servicesDisposable.dispose();
+            servicesDisposable = null;
+          }
+          break;
         case "lspStarted":
+          lspButton.disabled = false;
+          lspButton.classList.remove("is-loading");
+          lspButton.classList.remove("is-light");
+          lspButtonState.innerText = "ON";
           if (typeof message.root !== "string") {
             console.error("Unexpected message from server:", message);
             return;
@@ -272,16 +292,32 @@ async function main() {
           serviceLogLines[message.service] = lines;
           return;
         case "serviceFailed":
-          if (typeof message.service !== "string") {
+          if (
+            typeof message.service !== "string" ||
+            typeof message.error !== "string"
+          ) {
             console.error("Unexpected message from server:", message);
             return;
           }
-          formatButton.disabled = false;
-          formatButton.classList.remove("is-loading");
-          showError({
-            message: "Could not prettify code!",
-            data: serviceLogLines["formatter"].join("\n"),
-          });
+          switch (message.service) {
+            case "formatter":
+              formatButton.disabled = false;
+              formatButton.classList.remove("is-loading");
+              showError({
+                message: "Could not prettify code!",
+                data: serviceLogLines["formatter"].join("\n"),
+              });
+              break;
+            case "lsp":
+              lspButton.disabled = false;
+              lspButton.classList.remove("is-loading");
+              lspButton.classList.remove("is-light");
+              lspButtonState.innerText = "CRASHED";
+              break;
+            case "terminal":
+              term.write(`\r\n[${message.error}]`);
+              break;
+          }
           return;
         default:
           console.error("Unexpected message from server:", message);
@@ -352,9 +388,18 @@ async function main() {
     });
   }
   if (config.lsp) {
-    document.getElementById("lspButton").classList.remove("is-hidden");
-    document.getElementById("lspButton").addEventListener("click", () => {
-      // Do stuff here
+    lspButton.classList.remove("is-hidden");
+    lspButton.addEventListener("click", () => {
+      lspButton.classList.add("is-loading");
+      lspButton.disabled = true;
+      lspButton.classList.remove("is-light");
+      if (lspButtonState.innerText === "ON") {
+        sendMessage({ event: "lspStop" });
+      } else {
+        serviceLogBuffers["lsp"] = "";
+        serviceLogLines["lsp"] = [];
+        sendMessage({ event: "lspStart" });
+      }
     });
   }