const express = require("express");
const fetch = require("node-fetch");
const { URL } = require("url");

// Array of hostnames that will be proxied
const URL_WHITELIST = [
  "i.ytimg.com",
  "yt3.googleusercontent.com",
  "cdn.glitch.global",
  "cdn.statically.io",
  "site-assets.fontawesome.com",
  "fonts.gstatic.com",
  "yt3.ggpht.com",
  "tube.kuylar.dev",
  "lh3.googleusercontent.com",
  "is4-ssl.mzstatic.com",
  "is2-ssl.mzstatic.com",
  "is1-ssl.mzstatic.com",
  "fonts.bunny.net",
  "demo.matomo.org",
  "is5-ssl.mzstatic.com",
  "is3-ssl.mzstatic.com",
  "twemoji.maxcdn.com",
  "unpkg.com",
  "youtube.com",
  "returnyoutubedislikeapi.com",
  "inv.vern.cc",
  "invidious.privacydev.net",
  "inv.zzls.xyz",
  "vid.puffyan.us",
  "invidious.lidarshield.cloud",
  "invidious.epicsite.xyz",
  "invidious.esmailelbob.xyz",
];

const app = express();

app.use(express.json()); // for parsing application/json
app.use(express.urlencoded({ extended: true })); // for parsing application/x-www-form-urlencoded

app.use(function (req, res, next) {
  console.log(`=> ${req.method} ${req.originalUrl.slice(1)}`);
  next();
});

app.use(function (req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.setHeader("Cache-Control", "public, max-age=1848"); // cache header
  res.setHeader("poketube-cacher", "PROXY_FILES");

  next();
});

/**
 * @param {express.Request} req
 * @param {express.Response} res
 */
const proxy = async (req, res) => {
  try {
    let url;

    try {
      url = new URL("https://" + req.originalUrl.slice(10));
    } catch (e) {
      console.log("==> Cannot parse URL: " + e);
      return res.status(400).send("Malformed URL");
    }

    if (!URL_WHITELIST.includes(url.host)) {
      console.log(`==> Refusing to proxy host ${url.host}`);
      res.status(401).send(`Hostname '${url.host}' is not permitted`);
      return;
    }

    console.log(`==> Proxying request`);

    let f = await fetch(url + `?cachefixer=${btoa(Date.now())}`, {
      method: req.method,
    });

    f.body.pipe(res);
  } catch (e) {
    console.log(`==> Error: ${e}`);
    res.status(500).send("Internal server error");
  }
};

const listener = (req, res) => {
  proxy(req, res);
};

app.get("/", (req, res) => {
  var json = {
    status: "200",
    version: "1.0.0",
    URL_WHITELIST,
    cache: "max-age-1848",
  };

  res.json(json);
});

const apiUrl = "https://returnyoutubedislikeapi.com/votes?videoId=";

// Define a cache object
const cache = {};

app.get("/api", async (req, res) => {
  if (req.query.hash && req.query.hash === "d0550b6e28c8f93533a569c314d5b4e2") {
    try {
      const cacheKey = req.query.v;

      // Check if the result is already cached
      if (cache[cacheKey] && Date.now() - cache[cacheKey].timestamp < 3600000) {
        // If the cached result is less than 1 hour old, return it
        const cachedData = cache[cacheKey].data;
        const cachedDate = new Date(cache[cacheKey].timestamp);
        return res.json({ data: cachedData, cachedDate });
      }

      // If the result is not cached or is older than 1 hour, fetch it from the API
      const engagement = await fetch(apiUrl + req.query.v).then((res) =>
        res.json()
      );

      // Cache the result for future requests
      cache[cacheKey] = {
        data: engagement,
        timestamp: Date.now(),
      };

      res.json({ data: engagement, cachedDate: new Date() });
    } catch {}
  } else {
    return res.send("no hash query found");
  }
});

app.all("/*", listener);

app.listen(3000, () => console.log("Listening on 0.0.0.0:3000"));