import express from "express";
import path from "path";
import { fileURLToPath } from "url";
import bip39 from "bip39";
import crypto from "crypto";

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const app = express();
const trackerUrl = process.env.TRACKER_URL || "ws://localhost:8106";
const stunServerUrl = process.env.STUN_SERVER_URL;
const turnServerUrl = process.env.TURN_SERVER_URL;
const turnSecret = process.env.TURN_SECRET;
const turnTTL = 86400;

app.set("view engine", "ejs");
app.use(express.static(path.join(__dirname, "public")));

app.get("/generate-mnemonic/:infoHash", (req, res) => {
  const infoHash = req.params.infoHash;
  const mnemonic = bip39.entropyToMnemonic(infoHash);
  res.json({ mnemonic });
});

app.get("/get-infohash/:mnemonic", (req, res) => {
  const mnemonic = req.params.mnemonic;
  const infoHash = bip39.mnemonicToEntropy(mnemonic);
  res.json({ infoHash });
});

app.get("/turn-credentials", (req, res) => {
  const iceServers = [];

  if (stunServerUrl) {
    iceServers.push({ urls: stunServerUrl });
  }

  if (turnServerUrl && turnSecret) {
    const unixTimeStamp = Math.floor(Date.now() / 1000) + turnTTL;
    const username = `${unixTimeStamp}:transfercoffee`;
    const hmac = crypto.createHmac("sha1", turnSecret);
    hmac.update(username);
    const credential = hmac.digest("base64");

    iceServers.push({
      urls: turnServerUrl,
      username: username,
      credential: credential,
    });
  }

  res.json({ iceServers });
});

app.get("/:mnemonic?", (req, res) => {
  var mnemonic = req.params.mnemonic || "";

  if (mnemonic) {
    mnemonic = mnemonic.replaceAll(".", " ").trim();

    if (!bip39.validateMnemonic(mnemonic)) {
      return res.status(400).send("Invalid mnemonic");
    }
  }

  res.render("index", { trackerUrl, mnemonic });
});

const PORT = process.env.PORT || 8105;
app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});