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

const scriptDir = path.dirname(fileURLToPath(import.meta.url));
const rootDir = path.resolve(scriptDir, "../..");
const port = Number(process.env.HEROLL_MVP_PORT || 4173);
const parentPidFlag = process.argv.indexOf("--parent-pid");
const parentPid = parentPidFlag >= 0 ? Number(process.argv[parentPidFlag + 1]) : 0;
const mime = new Map([
  [".html", "text/html; charset=utf-8"],
  [".js", "text/javascript; charset=utf-8"],
  [".mjs", "text/javascript; charset=utf-8"],
  [".css", "text/css; charset=utf-8"],
  [".json", "application/json; charset=utf-8"],
  [".csv", "text/csv; charset=utf-8"],
  [".png", "image/png"],
  [".jpg", "image/jpeg"],
  [".jpeg", "image/jpeg"],
  [".svg", "image/svg+xml"],
  [".wav", "audio/wav"],
  [".ogg", "audio/ogg"]
]);

function safePath(urlPath) {
  const decoded = decodeURIComponent(urlPath.split("?")[0] || "/");
  const relative = decoded === "/" ? "mvp/index.html" : decoded.replace(/^\/+/, "");
  const resolved = path.resolve(rootDir, relative);
  if (!resolved.startsWith(rootDir + path.sep) && resolved !== rootDir) return null;
  return resolved;
}

const server = http.createServer(async (req, res) => {
  try {
    let target = safePath(req.url || "/");
    if (!target) {
      res.writeHead(403).end("Forbidden");
      return;
    }
    const info = await stat(target);
    if (info.isDirectory()) target = path.join(target, "index.html");
    const body = await readFile(target);
    res.writeHead(200, {
      "Content-Type": mime.get(path.extname(target).toLowerCase()) || "application/octet-stream",
      "Cache-Control": "no-store",
      "Cross-Origin-Resource-Policy": "same-origin"
    });
    res.end(body);
  } catch (error) {
    res.writeHead(404, { "Content-Type": "text/plain; charset=utf-8" });
    res.end(`Not found\n${String(error)}`);
  }
});

server.listen(port, "127.0.0.1", () => {
  console.log(`HEROLL MVP running at http://127.0.0.1:${port}/mvp/`);
  console.log("Press Ctrl+C to stop.");
});

if (Number.isInteger(parentPid) && parentPid > 0) {
  const parentWatch = setInterval(() => {
    try {
      process.kill(parentPid, 0);
    } catch {
      clearInterval(parentWatch);
      server.close(() => process.exit(0));
    }
  }, 1000);
  parentWatch.unref();
}