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 { inputData: null, suppliers: [], offers: [], checks: { c1: false, c2: false, c3: false } }; }
}
function writeData(data) {
  fs.writeFileSync(DATA, JSON.stringify(data, 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 === "GET" && req.url === "/api/data") {
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify(readData()));
  }
  
  if (req.method === "POST" && req.url === "/api/inputData") {
    const d = await body(req);
    const data = readData();
    data.inputData = d;
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "POST" && req.url === "/api/suppliers") {
    const s = await body(req);
    const data = readData();
    data.suppliers.push({ id: Date.now(), ...s });
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "POST" && req.url === "/api/offers") {
    const o = await body(req);
    const data = readData();
    data.offers.push({ id: Date.now(), ...o });
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "POST" && req.url === "/api/checks") {
    const c = await body(req);
    const data = readData();
    data.checks = c;
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "DELETE" && req.url.startsWith("/api/suppliers/")) {
    const id = parseInt(req.url.split("/")[3]);
    const data = readData();
    data.suppliers = data.suppliers.filter(s => s.id !== id);
    data.offers = data.offers.filter(o => o.supplierId !== id);
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  if (req.method === "DELETE" && req.url.startsWith("/api/offers/")) {
    const id = parseInt(req.url.split("/")[3]);
    const data = readData();
    data.offers = data.offers.filter(o => o.id !== id);
    writeData(data);
    res.writeHead(200, { "Content-Type": "application/json" });
    return res.end(JSON.stringify({ ok: true }));
  }
  
  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" : "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("Сервер запущен на порту " + PORT));