// Demo page logic for the ESM milestone: guest ESM executes through the browser's
// native module linker, fed by the Service Worker virtual origin (/~/ URLs backed
// by the kernel). 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();

try {
  const runtime = await boot();
  const read = async (p) => await (await fetch(p)).text();
  runtime.writeTree({
    "/app/main.mjs": await read("/demo/app/main.mjs"),
    "/app/greet.mjs": await read("/demo/app/greet.mjs"),
    "/app/legacy.cjs": await read("/demo/app/legacy.cjs"),
    "/app/name.txt": await read("/demo/app/name.txt"),
    "/app/node_modules/leftpad/package.json": await read("/demo/app/node_modules/leftpad/package.json"),
    "/app/node_modules/leftpad/index.js": await read("/demo/app/node_modules/leftpad/index.js"),
  });
  const proc = runtime.exec("/app/main.mjs");
  proc.stdout.pipeTo(new WritableStream({ write: (c) => { out.textContent += dec.decode(c); } }));
  proc.stderr.pipeTo(new WritableStream({ write: (c) => { errEl.textContent += dec.decode(c); } }));
  exitEl.textContent = String(await proc.exited);
} catch (e) {
  errEl.textContent = "BOOT FAILED: " + (e?.message ?? String(e));
  exitEl.textContent = "?";
}