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");

const EVENT = { name: "Корпоративный ивент 2026", date: "30.10.2026", place: "Алматы, ДК «Жибек жолы»", capacity: 400 };

function db() {
  try {
    const d = JSON.parse(fs.readFileSync(DATA, "utf8"));
    return { event: Object.assign(EVENT, d.event || {}), registrations: Array.isArray(d.registrations) ? d.registrations : [] };
  } catch (_) {
    return { event: EVENT, registrations: [] };
  }
}
function persist(d) {
  fs.writeFileSync(DATA, JSON.stringify(d, null, 2));
}
function readBody(req) {
  return new Promise((resolve) => {
    let s = "";
    req.on("data", (c) => { s += c; if (s.length > 1e6) req.destroy(); });
    req.on("end", () => { try { resolve(JSON.parse(s || "{}")); } catch (_) { resolve(null); } });
  });
}
function json(res, code, obj) {
  res.writeHead(code, { "Content-Type": "application/json; charset=utf-8" });
  res.end(JSON.stringify(obj));
}
const MIME = {
  ".html": "text/html", ".css": "text/css", ".js": "application/javascript", ".json": "application/json",
  ".png": "image/png", ".jpg": "image/jpeg", ".svg": "image/svg+xml", ".ico": "image/x-icon", ".woff2": "font/woff2", ".woff": "font/woff", ".ttf": "font/ttf"
};

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

  if (req.method === "GET" && url === "/api/registrations") {
    return json(res, 200, db().registrations);
  }

  if (req.method === "POST" && url === "/api/registrations") {
    const body = await readBody(req);
    if (!body) return json(res, 400, { ok: false, error: "Некорректные данные" });
    const name = String(body.name || "").trim().replace(/\s+/g, " ");
    const email = String(body.email || "").trim().toLowerCase();
    const phone = String(body.phone || "").trim();
    if (!name || name.length < 3) return json(res, 400, { ok: false, error: "Укажите ФИО" });
    if (!/^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email)) return json(res, 400, { ok: false, error: "Введите корректный адрес почты" });
    if (phone.replace(/\D/g, "").length < 10) return json(res, 400, { ok: false, error: "Укажите телефон" });
    const d = db();
    if (d.registrations.some((r) => r.email === email)) {
      return json(res, 409, { ok: false, error: "Заявка с этой почтой уже есть" });
    }
    const r = {
      id: Date.now(),
      name,
      email,
      phone,
      department: String(body.department || "").trim(),
      position: String(body.position || "").trim(),
      role: String(body.role || "Сотрудник"),
      track: String(body.track || "Все сессии"),
      food: String(body.food || "Обычное"),
      status: "Заявка",
      createdAt: new Date().toISOString()
    };
    d.registrations.push(r);
    persist(d);
    return json(res, 200, { ok: true, registration: r });
  }

  if (req.method === "PATCH" && /^\/api\/registrations\/\d+$/.test(url)) {
    const id = Number(url.split("/").pop());
    const body = await readBody(req);
    if (!body) return json(res, 400, { ok: false, error: "Некорректные данные" });
    const d = db();
    const r = d.registrations.find((x) => x.id === id);
    if (!r) return json(res, 404, { ok: false, error: "Заявка не найдена" });
    if ("status" in body) r.status = String(body.status || "Заявка");
    const note = String(body.note == null ? "" : body.note).trim();
    r.note = note;
    persist(d);
    return json(res, 200, { ok: true, registration: r });
  }

  let file = url === "/" ? "index.html" : url;
  file = file.replace(/^\/+/, "");
  const full = path.normalize(path.join(__dirname, file));
  if (!full.startsWith(__dirname)) return json(res, 403, { ok: false, error: "Forbidden" });
  if (fs.existsSync(full) && fs.statSync(full).isFile()) {
    res.writeHead(200, { "Content-Type": (MIME[path.extname(full)] || "application/octet-stream") + "; charset=utf-8" });
    return res.end(fs.readFileSync(full));
  }
  return json(res, 404, { ok: false, error: "Not found" });
}).listen(PORT, () => console.log("Сервер на порту " + PORT));