const { torrentFiles } = require('../lib/torrent');
const { getMetadata } = require('../lib/metadata');
const { parse } = require('parse-torrent-title');
const { Type } = require('./types');

const MIN_SIZE = 20 * 1024 * 1024; // 20 MB

async function parseTorrentFiles(torrent, imdbId) {
  if (torrent.type === Type.MOVIE) {
    return [{
      infoHash: torrent.infoHash,
      title: torrent.title,
      size: torrent.size,
      imdbId: imdbId,
    }];
  }
  const parsedTorrentName = parse(torrent.title);
  if (parsedTorrentName.season && parsedTorrentName.episode) {
    return [{
      infoHash: torrent.infoHash,
      title: torrent.title,
      size: torrent.size,
      imdbId: imdbId,
      imdbSeason: parsedTorrentName.season,
      imdbEpisode: parsedTorrentName.episode
    }];
  }

  return torrentFiles(torrent)
      .then(files => files
          .filter(file => file.size > MIN_SIZE)
          .map(file => parseFile(file, parsedTorrentName)))
      .then(files => decomposeAbsoluteEpisodes(files, torrent, imdbId))
      .then(files => files
          .filter(file => file.season && file.episodes && file.episodes.length)
          .map(file => file.episodes.map(episode => ({
              infoHash: torrent.infoHash,
              fileIndex: file.fileIndex,
              title: file.name,
              size: file.size,
              imdbId: imdbId,
              imdbSeason: file.season,
              imdbEpisode: episode})))
          .reduce((a, b) => a.concat(b), []))
      .catch(error => {
        console.log(`Failed getting files for ${torrent.title}`, error.message);
        return [];
      });
}

function parseFile(file, parsedTorrentName) {
  const fileInfo = parse(file.name);
  // the episode may be in a folder containing season number
  if (!fileInfo.season && parsedTorrentName.season) {
    fileInfo.season = parsedTorrentName.season;
  } else if (!fileInfo.season && file.path.includes('/')) {
    const folders = file.path.split('/');
    const pathInfo = parse(folders[folders.length - 2]);
    fileInfo.season = pathInfo.season;
  }

  return { ...file, ...fileInfo };
}

async function decomposeAbsoluteEpisodes(files, torrent, imdbId) {
  if (files.every((file) => file.episodes.every((ep) => ep < 100))) {
    return; // nothing to decompose
  }

  const metadata = await getMetadata(imdbId, torrent.type || Type.MOVIE);
  // decompose if season is inside path, but individual files are concatenated ex. 101 (S01E01)
  files
      .filter(file => file.season && metadata.episodeCount[file.season] < 100)
      .filter(file => file.episodes.every(ep => ep / 100 === file.season))
      .forEach(file => file.episodes = file.episodes.map(ep => ep % 100));
  // decompose if no season info is available, but individual files are concatenated ex. 101 (S01E01)
  // based on total episodes count per season

  return files;
}

module.exports = { parseTorrentFiles };