const axios = require('axios');
const magnet = require('magnet-uri');
const { getRandomUserAgent } = require('../lib/requestHelper');
const { getTorrent } = require('../lib/repository');
const { Type } = require('../lib/types');

const TRACKERS_URL = 'https://web.archive.org/web/20230823105403id_/https://raw.githubusercontent.com/ngosang/trackerslist/master/trackers_best.txt';
const DEFAULT_TRACKERS = [
  "udp://47.ip-51-68-199.eu:6969/announce",
  "udp://9.rarbg.me:2940",
  "udp://9.rarbg.to:2820",
  "udp://exodus.desync.com:6969/announce",
  "udp://explodie.org:6969/announce",
  "udp://ipv4.tracker.harry.lu:80/announce",
  "udp://open.stealth.si:80/announce",
  "udp://opentor.org:2710/announce",
  "udp://opentracker.i2p.rocks:6969/announce",
  "udp://retracker.lanta-net.ru:2710/announce",
  "udp://tracker.cyberia.is:6969/announce",
  "udp://tracker.dler.org:6969/announce",
  "udp://tracker.ds.is:6969/announce",
  "udp://tracker.internetwarriors.net:1337",
  "udp://tracker.openbittorrent.com:6969/announce",
  "udp://tracker.opentrackr.org:1337/announce",
  "udp://tracker.tiny-vps.com:6969/announce",
  "udp://tracker.torrent.eu.org:451/announce",
  "udp://valakas.rollo.dnsabr.com:2710/announce",
  "udp://www.torrent.eu.org:451/announce",
]
const ANIME_TRACKERS = [
  "http://nyaa.tracker.wf:7777/announce",
  "http://anidex.moe:6969/announce",
  "http://tracker.anirena.com:80/announce",
  "udp://tracker.uw0.xyz:6969/announce",
  "http://share.camoe.cn:8080/announce",
  "http://t.nyaatracker.com:80/announce",
];
const RUSSIAN_TRACKERS = [
  "udp://opentor.org:2710",
  "http://retracker.local/announce",
  "http://bt.t-ru.org/ann?magnet",
  "http://bt2.t-ru.org/ann?magnet",
  "http://bt3.t-ru.org/ann?magnet",
  "http://bt4.t-ru.org/ann?magnet",
];
// Some trackers have limits on original torrent trackers,
// where downloading ip has to seed the torrents for some amount of time,
// thus it doesn't work on mochs.
// So it's better to exclude them and try to download through DHT,
// as the torrent won't start anyway.
const RUSSIAN_PROVIDERS = [
  'Rutor',
  'Rutracker'
];
const ANIME_PROVIDERS = [
  'HorribleSubs',
  'NyaaSi',
  'NyaaPantsu'
];
let BEST_TRACKERS = [];
let ALL_ANIME_TRACKERS = [];
let ALL_RUSSIAN_TRACKERS = [];

async function getMagnetLink(infoHash) {
  const torrent = await getTorrent(infoHash).catch(() => ({ infoHash }));
  const torrentTrackers = torrent.trackers && torrent.trackers.split(',');
  const animeTrackers = torrent.type === Type.ANIME ? ALL_ANIME_TRACKERS : undefined;
  const providerTrackers = RUSSIAN_PROVIDERS.includes(torrent.provider) && ALL_RUSSIAN_TRACKERS;
  const trackers = unique([].concat(torrentTrackers).concat(animeTrackers).concat(providerTrackers));

  return trackers
      ? magnet.encode({ infoHash: infoHash, announce: trackers })
      : magnet.encode({ infoHash: infoHash });
}

async function initBestTrackers() {
  BEST_TRACKERS = await getBestTrackers();
  ALL_ANIME_TRACKERS = unique(BEST_TRACKERS.concat(DEFAULT_TRACKERS).concat(ANIME_TRACKERS));
  ALL_RUSSIAN_TRACKERS = unique(BEST_TRACKERS.concat(DEFAULT_TRACKERS).concat(RUSSIAN_TRACKERS));
  console.log('Retrieved best trackers: ', BEST_TRACKERS);
}

async function getBestTrackers(retry = 2) {
  const options = { timeout: 30000, headers: { 'User-Agent': getRandomUserAgent() } };
  return axios.get(TRACKERS_URL, options)
      .then(response => response.data && response.data.trim())
      .then(body => body && body.split('\n\n') || [])
      .catch(error => {
        if (retry === 0) {
          console.log(`Failed retrieving best trackers: ${error.message}`);
          throw error;
        }
        return getBestTrackers(retry - 1);
      });
}

function getSources(trackersInput, infoHash) {
  if (!trackersInput) {
    return null;
  }
  const trackers = Array.isArray(trackersInput) ? trackersInput : trackersInput.split(',');
  return trackers.map(tracker => `tracker:${tracker}`).concat(`dht:${infoHash}`);
}

function enrichStreamSources(stream) {
  const match = stream.title.match(/⚙.* ([^ \n]+)/);
  const provider = match && match[1];
  if (ANIME_PROVIDERS.includes(provider)) {
    const sources = getSources(ALL_ANIME_TRACKERS, stream.infoHash);
    return { ...stream, sources };
  }
  if (RUSSIAN_PROVIDERS.includes(provider)) {
    const sources = unique([].concat(stream.sources || []).concat(getSources(ALL_RUSSIAN_TRACKERS, stream.infoHash)));
    return { ...stream, sources };
  }
  return stream;
}

function unique(array) {
  return Array.from(new Set(array));
}

module.exports = { initBestTrackers, getMagnetLink, getSources, enrichStreamSources };