server.ts

import { createServer } from "node:http";
import type { Duplex } from "node:stream";
import next from "next";
import { WebSocketServer } from "ws";
import { BROWSERBOX_WS_PATH } from "@/lib/ws-path";
import { attachBrowserboxWebSocketServer } from "@/lib/server/ws-http-server";

const dev = process.env.NODE_ENV !== "production";
const hostname = process.env.HOSTNAME ?? "localhost";
const port = Number.parseInt(process.env.PORT ?? "3000", 10);
const bindHost = process.env.HOST ?? "0.0.0.0";

const app = next({ dev, hostname, port });

/** `IncomingMessage.url` is path + query only; WHATWG URL needs a base. */
function pathnameFromRequestUrl(urlPath: string | undefined): string {
  if (!urlPath) return "";
  try {
    return new URL(urlPath, "http://internal.invalid").pathname;
  } catch {
    return "";
  }
}

const wss = new WebSocketServer({ noServer: true });
attachBrowserboxWebSocketServer(wss);

void app.prepare().then(() => {
  const handle = app.getRequestHandler();
  const upgradeHandler = app.getUpgradeHandler();

  const server = createServer((req, res) => {
    void handle(req, res);
  });

  server.on("upgrade", (request, socket, head) => {
    const pathname = pathnameFromRequestUrl(request.url);
    if (pathname === BROWSERBOX_WS_PATH) {
      wss.handleUpgrade(request, socket, head, (ws) => {
        wss.emit("connection", ws, request);
      });
    } else {
      void upgradeHandler(request, socket as Duplex, head);
    }
  });

  server.listen(port, bindHost, () => {
    console.log(
      `> Ready on http://${hostname}:${port} (WS ${BROWSERBOX_WS_PATH})`,
    );
  });
});