import express from "express";
import fs from "fs";
import path from "path";
import { fileURLToPath } from "url";

const __dirname = path.dirname(fileURLToPath(import.meta.url));
const app = express();
app.use(express.json());
app.use(express.static(path.join(__dirname, "public")));

const stateFile = path.join(__dirname, "state.json");

// Initialzustand laden oder erzeugen
function getState() {
  if (!fs.existsSync(stateFile)) {
    fs.writeFileSync(stateFile, JSON.stringify({ current: "A" }, null, 2));
  }
  return JSON.parse(fs.readFileSync(stateFile));
}

function setState(newState) {
  fs.writeFileSync(stateFile, JSON.stringify(newState, null, 2));
}

// GET: aktuellen Zustand
app.get("/status", (req, res) => {
  res.json(getState());
});

// POST: wechseln
app.post("/toggle", (req, res) => {
  const state = getState();
  state.current = state.current === "A" ? "B" : "A";
  setState(state);
  res.json(state);
});

// Start
const PORT = process.env.PORT || 3000;
app.listen(PORT, () => console.log(`Zahl-Schalter läuft auf Port ${PORT}`));