Code improvements.

extension/src/webview/WebviewServer.ts

@@ -0,0 +1,94 @@
+import { WebSocketStream } from "@hediet/typed-json-rpc-websocket";
+import { AddressInfo } from "net";
+import WebSocket = require("ws");
+import { WebviewConnection } from "./WebviewConnection";
+import * as express from "express";
+import * as http from "http";
+import * as serveStatic from "serve-static";
+import { Config } from "../Config";
+import cryptoRandomString = require("crypto-random-string");
+import { distPath } from "debug-visualizer-webview";
+import { EvaluationWatchService } from "../EvaluationWatchService/EvaluationWatchService";
+import { URLSearchParams } from "url";
+import { autorun, reaction } from "mobx";
+
+export class WebviewServer {
+	private readonly server: http.Server;
+	public readonly secret = cryptoRandomString({ length: 30 });
+
+	public readonly connections = new Set<WebviewConnection>();
+
+	constructor(
+		dataSource: EvaluationWatchService,
+		private readonly config: Config
+	) {
+		const app = express();
+
+		app.use(serveStatic(distPath));
+
+		this.server = app.listen();
+
+		console.log(
+			`Serving "${distPath}" on port ${
+				(this.server.address() as AddressInfo).port
+			}`
+		);
+
+		const wss = new WebSocket.Server({ server: this.server });
+		wss.on("connection", async ws => {
+			const stream = new WebSocketStream(ws);
+			const c = new WebviewConnection(
+				dataSource,
+				stream,
+				this,
+				config,
+				this.secret
+			);
+			this.connections.add(c);
+			await stream.onClosed;
+			this.connections.delete(c);
+		});
+
+		reaction(
+			() => config.theme,
+			theme => {
+				for (const c of this.connections) {
+					c.setTheme(theme);
+				}
+			}
+		);
+	}
+
+	public getWebviewPageUrl(args: {
+		expression?: string;
+		mode: "standalone" | "webviewIFrame";
+	}): string {
+		const port = process.env.USE_DEV_UI ? 8081 : this.port;
+		const params: Record<string, string> = {
+			serverPort: this.port.toString(),
+			serverSecret: this.secret,
+			mode: args.mode,
+			theme: this.config.theme,
+		};
+		if (args.expression !== undefined) {
+			params.expression = args.expression;
+		}
+
+		return `http://localhost:${port}/index.html?${new URLSearchParams(
+			params
+		).toString()}`;
+	}
+
+	public get publicPath(): string {
+		return `http://localhost:${this.port}/`;
+	}
+
+	public get webviewBundleUrl(): string {
+		return `${this.publicPath}main.js`;
+	}
+
+	public get port(): number {
+		const httpPort = (this.server.address() as AddressInfo).port;
+		return httpPort;
+	}
+}