/**
 * Custom Next.js server so we can attach a plain WebSocket server for WebRTC
 * signaling (offer/answer/ICE relay) alongside the normal Next.js request
 * handler. Standalone output mode can't be combined with a custom server
 * (see next.config.ts), so this project deploys by running this file
 * directly (`npm run start` / `npm run dev`) instead of `next start`.
 *
 * The WS server never touches audio/video/screen-share media — it only
 * relays small JSON signaling messages between participants of the same
 * meeting room (see lib/meeting/signalingServer.ts).
 */
import { createServer } from "node:http";
import next from "next";
import { WebSocketServer } from "ws";
import { attachSignalingServer } from "./lib/meeting/signalingServer";

const port = parseInt(process.env.PORT || "3000", 10);
const hostname = process.env.HOSTNAME || "0.0.0.0";
const dev = process.env.NODE_ENV !== "production";

const app = next({ dev, hostname, port });
const SIGNALING_PATH = "/ws/signaling";

app.prepare().then(() => {
  // Must be requested after prepare() resolves.
  const handle = app.getRequestHandler();
  const upgradeHandle = app.getUpgradeHandler();

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

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

  server.on("upgrade", (req, socket, head) => {
    const url = req.url ?? "";
    if (url.startsWith(SIGNALING_PATH)) {
      wss.handleUpgrade(req, socket, head, (ws) => {
        wss.emit("connection", ws, req);
      });
    } else {
      // Let Next.js handle its own upgrade requests (e.g. dev-mode HMR).
      upgradeHandle(req, socket, head);
    }
  });

  server.listen(port, () => {
    console.log(
      `> ANOUMA server listening at http://${hostname}:${port} (${dev ? "development" : "production"}), signaling on ${SIGNALING_PATH}`,
    );
  });
});