const http = require("http");
const fs = require("fs");
const path = require("path");

const PORT = process.env.PORT || 3000;
const DATA = path.join(__dirname, "data.json");

function readData() {
  try { return JSON.parse(fs.readFileSync(DATA, "utf8")); } catch (_) { return { registrations: [] }; }
}
function writeData(d) {
  fs.writeFileSync(DATA, JSON.stringify(d, null, 2));
}
function body(req) {
  return new Promise((resolve) => {
    let s = "";
    req.on("data", (c) => (s += c));
    req.on("end", () => { try { resolve(JSON.parse(s || "{}")); } catch (_) { resolve({}); } });
  });
}

http.createServer(async (req, res) => {
  const url = req.url.split("?")[0];

  if (req.method === "GET" && url === "/api/registrations") {
    const d = readData();
    res.writeHead(200, { "Content-Type": "application/json; charset=utf-8" });
    return res.end(JSON.stringify(d.registrations));
  }

  if (req.method === "POST" && url === "/api/registrations") {
    const r = await body(req);
    if (!r.name || !r.phone) {
      res.writeHead(400, { "Content-Type": "application/json; charset=utf-8" });
      return res.end(JSON.stringify({ ok: false, error: "name and phone are required" }));
    }
    const d = readData();
    const rec = {
      id: Date.now(),
      name: String(r.name).trim(),
      dept: String(r.dept || "").trim(),
      phone: String(r.phone).trim(),
      email: String(r.email || "").trim(),
      size: String(r.size || "").trim(),
      allergies: String(r.allergies || "").trim(),
      comment: String(r.comment || "").trim(),
      createdAt: new Date().toISOString()
    };
    d.registrations.push(rec);
    writeData(d);
    res.writeHead(200, { "Content-Type": "application/json; charset=utf-8" });
    return res.end(JSON.stringify({ ok: true, id: rec.id }));
  }

  const safe = decodeURIComponent(url) || "/";
  let file = safe === "/" ? "/index.html" : safe;
  const full = path.join(__dirname, file);
  if (full.startsWith(__dirname) && fs.existsSync(full) && fs.statSync(full).isFile()) {
    const ext = path.extname(full).toLowerCase();
    const types = { ".css": "text/css", ".js": "application/javascript", ".html": "text/html", ".png": "image/png", ".svg": "image/svg+xml", ".jpg": "image/jpeg", ".jpeg": "image/jpeg", ".webp": "image/webp", ".ico": "image/x-icon" };
    res.writeHead(200, { "Content-Type": (types[ext] || "application/octet-stream") + "; charset=utf-8" });
    return res.end(fs.readFileSync(full));
  }

  res.writeHead(404, { "Content-Type": "text/plain; charset=utf-8" });
  res.end("Not found");
}).listen(PORT, () => console.log("Сервер на порту " + PORT));