// Bundles the 2026 explorer's standalone build (eqtylab/explorer `dist/standalone`, built
// from the `preview` branch with `pnpm build:standalone`) into one self-contained
// explorer/explorer.js: lazy chunks, highlighter grammars and wasm all inline.
//
// Why: same reason as legacy/bundle.mjs. In a private Space only a request carrying the
// `__sign` token is authorized inside the huggingface.co embed, and the standalone build
// fetches its chunks and wasm relative to itself, without the token. One file = one
// request, which index.html makes with the token.
//
// Usage: node explorer/bundle.mjs [path/to/explorer/dist/standalone]
import { build } from "esbuild";
import { readFileSync, writeFileSync, readdirSync, mkdtempSync, cpSync } from "node:fs";
import { join, dirname } from "node:path";
import { tmpdir } from "node:os";
import { fileURLToPath } from "node:url";

const here = dirname(fileURLToPath(import.meta.url));
const src = process.argv[2] || join(here, "../../../EQTY/explorer/dist/standalone");

const work = mkdtempSync(join(tmpdir(), "explorer-"));
cpSync(src, work, { recursive: true });

// new URL("x.wasm", import.meta.url) -> a data: URI (the wasm loaders accept those)
const wasmUri = (f) => `data:application/wasm;base64,${readFileSync(join(work, f)).toString("base64")}`;
let inlined = 0;
for (const f of readdirSync(work).filter((f) => f.endsWith(".js"))) {
  const path = join(work, f);
  const text = readFileSync(path, "utf8").replace(/new URL\("([\w.-]+\.wasm)",import\.meta\.url\)/g, (m, w) => {
    inlined++;
    return `new URL("${wasmUri(w)}")`;
  });
  writeFileSync(path, text);
}
const wasmCount = readdirSync(work).filter((f) => f.endsWith(".wasm")).length;
if (inlined < wasmCount) throw new Error(`inlined ${inlined} wasm references, expected at least ${wasmCount}`);

// esbuild folds the dynamic imports (verifier chunk, ./grammars/${lang}.js) into the bundle.
const out = await build({
  entryPoints: [join(work, "explorer.js")], bundle: true, format: "esm", write: false, minify: true,
  target: "es2022", logLevel: "warning", legalComments: "none",
});
const js = out.outputFiles[0].text;

const banner = `// 2026 explorer (@eqtylab/explorer standalone, preview branch). Generated by explorer/bundle.mjs; don't edit.\n`;
writeFileSync(join(here, "explorer.js"), banner + js);
console.log(`explorer/explorer.js: ${(js.length / 1e6).toFixed(2)} MB (${inlined} wasm inlined)`);