const express = require("express");
// const fetch = require("node-fetch");
const { URL } = require("url");
const { Readable } = require("node:stream");

// Array of hostnames that will be proxied
const URL_WHITELIST = require("./whitelist.json");

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=864000"); // cache header
  res.setHeader("poketube-cacher", "PROXY_FILES");

  next();
});

/**
 * @param {express.Request} req
 * @param {express.Response} res
 */
const proxy = async (req, res) => {
    const { fetch } = await import("undici")
  res.setHeader("Cache-Control", "public, max-age=864000"); // cache header

  try {
    let url;

    try {
      url = new URL("https://" + req.originalUrl.slice(8));
    } 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,
    });

Readable.fromWeb(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: "1.3.0",
    URL_WHITELIST,
    cache: "max-age-864000",
  };

  res.json(json);
});

const apiUrls = [
  "https://returnyoutubedislikeapi.com/votes?videoId=",
  "https://prod-poketube.testing.poketube.fun/api?v=",
  "https://ipv6-t.poketube.fun/api?v="
];

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

app.get("/api", async (req, res) => {
const { fetch } = await import("undici")

  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(cachedData);
    }

    // Initialize an array to store errors when trying different URLs
    const errors = [];

    for (const apiUrl of apiUrls) {
      try {
        // Fetch data from the current URL
        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(engagement);
        return; // Exit the loop if successful
      } catch (err) {
        // Log the error for this URL and continue to the next URL
        console.log(`Error fetching data from ${apiUrl}: ${err.message}`);
        errors.push(err.message);
        return "";
      }
    }

    // If all URLs fail, return an error response
    res.status(500).json({ error: "All API endpoints failed", errors });
  } catch (err) {
    console.log(err);
  }
});

app.get("/bangs", async (req, res) => {
    const { fetch } = await import("undici")

    let f = await fetch("https://lite.duckduckgo.com/lite/?q=" + req.query.q, {
      method: req.method,
    });

    res.redirect(f);
  
});

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

app.listen(6014, () => console.log("Listening on 0.0.0.0:6014"));