require('dotenv').config();
const { Readable } = require("stream");
const { GetListByKeyword } = require("youtube-search-api");
const skewered = require("skewered");
const { createClient } = require("fix-esm").require("webdav");
const path = require("path");
const { readFileSync, writeFileSync } = require("fs");

function pathGenerator({ url, name, channelName }) {
  return path.join(process.env.NEXTCLOUD_FOLDER, `${url}-${skewered(`${name} - ${channelName}`)}.mp3`)
}

function checkLastSong({ name, channelName }) {
  const curSong = readFileSync(path.join(__dirname, "last_song.txt"), 'utf8');

  return (curSong === `${name} - ${channelName}`);
}

function writeLastSong({ name, channelName }) {
  writeFileSync(path.join(__dirname, "last_song.txt"), `${name} - ${channelName}`, 'utf8');

  return null;
}

async function getVideo() {
  const trackData = await fetch(
    `https://${process.env.LASTFM_INSTANCE}/2.0/?method=user.getrecenttracks&user=${process.env.LASTFM_USERNAME}&api_key=${process.env.LASTFM_API_KEY}&format=json&limit=1&extended=1`
  ).then(x => x.json()).then(data => data.recenttracks.track[0]);

  if (checkLastSong({
    name: trackData.name,
    channelName: trackData.artist.name
  })) {
    console.log("Last song check failed");
    return null;
  } else {
    console.log("Last song check succeeded, writing file");
    writeLastSong({
      name: trackData.name,
      channelName: trackData.artist.name
    });
  }

  const videoList = await GetListByKeyword(`${trackData.artist.name} - ${trackData.name}`, false, 1, [
    {type: "video"}
  ]);

  const musicVideo = videoList.items[0];
  
  return {
    url: musicVideo.id,
    name: musicVideo.title,
    channelName: musicVideo.channelTitle
  };
}

async function checkNextcloud({ url, name, channelName }, nextcloudClient) {
  const fileName = pathGenerator({ url, name, channelName });

  return await nextcloudClient.exists(fileName);
}

async function downloadFromCobalt({ url, name, channelName }) {
  const processor = await fetch(`https://${process.env.COBALT_INSTANCE}/api/json`, {
    method: "POST",
    body: JSON.stringify({
      url: `https://youtu.be/${url}`,
      vCodec: "h264",
      vQuality: "144",
      aFormat: "mp3",
      filenamePattern: "basic",
      isAudioOnly: true,
      disableMetadata: false
    }),
    headers: [
      ["Accept", "application/json"],
      ["Content-Type", "application/json"],
    ]
  }).then(x => x.json());

  let processorURL;

  switch (processor.status) {
    case 'error':
    case 'rate-limit':
      throw new Error(`Error! (${processor.text})`);
    case 'redirect':
      processorURL = processor.audio || processor.url;
      break;
    case 'picker':
      throw new Error("Can't handle picker!");
    case 'stream':
      const streamProcessor = await fetch(`${processor.url}&p=1`).then(x => x.json());

      if (streamProcessor.status === "continue")
        processorURL = processor.audio || processor.url;
      else processorURL = processor.audio || processor.url;

      break;
    default: 
      processorURL = processor.audio || processor.url;
      break;
  }

  const { body } = await fetch(processorURL);

  return {
    fileStream: Readable.fromWeb(body),
    url,
    name,
    channelName
  };
}

async function uploadToNextcloud({ fileStream, url, name, channelName }, nextcloudClient) {
  await nextcloudClient.createDirectory(process.env.NEXTCLOUD_FOLDER, {
    recursive: true,
  });

  const fileName = pathGenerator({ url, name, channelName });
  fileStream.pipe(nextcloudClient.createWriteStream(fileName));

  return fileName;
}

async function main() {
  const video = await getVideo();
  console.log(video);

  if (video == null) return null;

  const nextcloudClient = createClient(
    `https://${process.env.NEXTCLOUD_INSTANCE}/remote.php/dav/files/${process.env.NEXTCLOUD_USERNAME}/`,
    {
      username: process.env.NEXTCLOUD_USERNAME,
      password: process.env.NEXTCLOUD_PASSWORD,
    }
  );
  
  if (await checkNextcloud(video, nextcloudClient)) return null;

  const cobalt = await downloadFromCobalt(video);
  console.log(cobalt);
  const nextcloud = await uploadToNextcloud(cobalt, nextcloudClient);
  console.log(nextcloud);
  return nextcloud;
}

main();