// Demo page logic for guest node:http: the guest listens on a port, the page waits
// for it and mounts an iframe on the /~/@<host>/http/<port>/ virtual origin. ?esm runs the
// ESM variant of the server. Runs on the page (host side).
import { boot } from "@nibling/kernel";

const out = document.getElementById("out");
const errEl = document.getElementById("err");
const exitEl = document.getElementById("exit");
const dec = new TextDecoder();
const entry = new URLSearchParams(location.search).has("esm") ? "/app/server.mjs" : "/app/server.cjs";

try {
  const runtime = await boot();
  const source = await (await fetch(`/demo${entry}`)).text();
  runtime.writeTree({ [entry]: source });
  const proc = runtime.exec(entry);
  proc.stdout.pipeTo(new WritableStream({ write: (c) => { out.textContent += dec.decode(c); } }));
  proc.stderr.pipeTo(new WritableStream({ write: (c) => { errEl.textContent += dec.decode(c); } }));
  proc.exited.then((code) => { exitEl.textContent = String(code); });

  const url = await runtime.waitForPort(3000);
  const frame = document.createElement("iframe");
  frame.id = "app";
  frame.title = "guest server on port 3000";
  frame.src = url;
  document.body.append(frame);
} catch (e) {
  errEl.textContent = "BOOT FAILED: " + (e?.message ?? String(e));
  exitEl.textContent = "?";
}