/**
 * Bundle the guest shell into a string the host can evaluate.
 *
 * The shell runs inside QuickJS, which has no module loader and no filesystem,
 * so it has to arrive as source text. Emitting it as a `.ts` module rather than
 * a `.js` asset is what lets every consumer — Vite for the browser build, plain
 * Node for the benchmarks — get at it the same way, with no loader plugin and
 * no `?raw` import that only one bundler understands.
 *
 * The output is committed, like the wasm packages are, so a checkout builds
 * without this step having run.
 */

import { build } from "esbuild";
import { mkdirSync, writeFileSync } from "node:fs";
import { dirname, join } from "node:path";
import { fileURLToPath } from "node:url";

const here = dirname(fileURLToPath(import.meta.url));
const outDir = join(here, "src", "generated");

const result = await build({
  entryPoints: [join(here, "src", "guest", "index.ts")],
  bundle: true,
  write: false,
  // A script, not a module: the host evaluates it with `evalCode`, and it
  // announces itself by assigning `globalThis.__yaak_guest`.
  format: "iife",
  // Nothing here may reach for a Node built-in, and "browser" is the closest
  // description of a target with globals and no filesystem. QuickJS itself has
  // fewer globals than any browser, which is what `guest/globals.ts` is for.
  platform: "browser",
  // QuickJS is ES2023-complete, so nothing needs downleveling. Keeping the
  // source as written also keeps stack traces from the guest readable.
  target: "es2022",
  minify: false,
  legalComments: "none",
});

const source = result.outputFiles[0].text;

mkdirSync(outDir, { recursive: true });
writeFileSync(
  join(outDir, "guest.ts"),
  [
    "// Generated by build-guest.mjs. Do not edit.",
    "//",
    "// The runtime shell, as source text, for evaluation inside QuickJS.",
    "// Regenerate with `npm run build --workspace @yaakapp-internal/plugin-sandbox`.",
    "",
    `export const GUEST_SOURCE = ${JSON.stringify(source)};`,
    "",
  ].join("\n"),
);

console.log(`Bundled guest shell: ${(source.length / 1024).toFixed(1)} KB`);