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 readDb() {
  try { return JSON.parse(fs.readFileSync(DATA, "utf8")); } catch (_) { return { state: null }; }
}
function writeDb(db) {
  fs.writeFileSync(DATA, JSON.stringify(db, 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({}); } });
  });
}

const TYPES = { ".html": "text/html", ".css": "text/css", ".js": "application/javascript", ".svg": "image/svg+xml", ".png": "image/png", ".ico": "image/x-icon" };

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

  if (req.method === "GET" && url === "/api/state") {
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify(readDb().state || {}));
  }
  if (req.method === "POST" && url === "/api/state") {
    const st = await body(req);
    const db = readDb();
    db.state = st;
    writeDb(db);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }

  let file = url === "/" ? "/index.html" : url;
  const full = path.join(__dirname, file);
  if (full.startsWith(__dirname) && fs.existsSync(full) && fs.statSync(full).isFile()) {
    res.writeHead(200, { "Content-Type": (TYPES[path.extname(full)] || "application/octet-stream") + "; charset=utf-8" });
    return res.end(fs.readFileSync(full));
  }
  res.writeHead(404); res.end("Not found");
}).listen(PORT, () => console.log("Режим дня: сервер на порту " + PORT));