// Optional static file server for local development.
//
// The tool is a pure static single page — it needs no backend (the recording
// upload happens in the browser via a CORS relay, see public/app.js). This
// server exists only so ES modules load over http:// during local dev, since
// browsers block module imports from file://. Any static server works just as
// well (e.g. `python3 -m http.server`).

import http from "node:http";
import { readFile } from "node:fs/promises";
import { extname, join, normalize } from "node:path";
import { fileURLToPath } from "node:url";

const ROOT = join(fileURLToPath(new URL(".", import.meta.url)), "public");
const PORT = process.env.PORT || 8080;

const MIME = {
  ".html": "text/html; charset=utf-8",
  ".js": "text/javascript; charset=utf-8",
  ".css": "text/css; charset=utf-8",
  ".json": "application/json; charset=utf-8",
  ".svg": "image/svg+xml",
};

const server = http.createServer(async (req, res) => {
  let path = decodeURIComponent(new URL(req.url, "http://x").pathname);
  if (path === "/") path = "/index.html";
  const filePath = normalize(join(ROOT, path));
  if (!filePath.startsWith(ROOT)) {
    res.writeHead(403).end("forbidden");
    return;
  }
  try {
    const data = await readFile(filePath);
    res.writeHead(200, {
      "content-type": MIME[extname(filePath)] || "application/octet-stream",
      "cache-control": "no-store",
    });
    res.end(data);
  } catch {
    res.writeHead(404).end("not found");
  }
});

server.listen(PORT, () => {
  console.log(`Blob Opera MIDI Embed (static) running at http://localhost:${PORT}`);
});