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 readAll() {
  try { return JSON.parse(fs.readFileSync(DATA, "utf8")); } catch (_) { return { rsvps: [] }; }
}
function writeAll(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) => {
  if (req.method === "POST" && req.url.split("?")[0] === "/api/rsvp") {
    const item = await body(req);
    const d = readAll();
    d.rsvps.push({
      id: Date.now(),
      name: String(item.name || "").slice(0, 80),
      guests: parseInt(item.guests, 10) || 1,
      attendance: item.attendance === "no" ? "no" : "yes",
      note: String(item.note || "").slice(0, 300),
      createdAt: new Date().toISOString(),
    });
    writeAll(d);
    res.writeHead(200, { "Content-Type": "application/json; charset=utf-8" });
    return res.end(JSON.stringify({ ok: true }));
  }
  if (req.method === "GET" && req.url.split("?")[0] === "/api/rsvp") {
    res.writeHead(200, { "Content-Type": "application/json; charset=utf-8" });
    return res.end(JSON.stringify(readAll().rsvps));
  }
  let file = req.url === "/" ? "/index.html" : req.url.split("?")[0];
  const full = path.join(__dirname, file);
  if (full.startsWith(__dirname) && fs.existsSync(full) && fs.statSync(full).isFile()) {
    const ext = path.extname(full);
    const type = ext === ".css" ? "text/css" : ext === ".js" ? "application/javascript" : ext === ".svg" ? "image/svg+xml" : "text/html";
    res.writeHead(200, { "Content-Type": type + "; charset=utf-8" });
    return res.end(fs.readFileSync(full));
  }
  res.writeHead(404); res.end("Not found");
}).listen(PORT, () => console.log("Server on port " + PORT));