import fs from 'fs';
import https from 'https';
import chalk from 'chalk';
import load from 'dotenv';
load()

let songCount = 1;

const AUTHTOKEN = process.env.AUTHTOKEN;
const TOKEN = process.env.TOKEN;
const USERID = process.env.USERID;

if(!AUTHTOKEN || !TOKEN || !USERID) {
  console.error('Please enter all the required information');
  process.exit(1);
}



let genres = [
  "Beach",
  "Chimes & Bowls",
  "Forest",
  "Nightsounds",
  "Rain",
  "Rainforest",
  "River",
  "Thunder",
  "Underwater",
  "Wind",
  "Acoustic",
  "Atmospheric",
  "Cinematic",
  "Classical",
  "Drone",
  "Electronic",
  "Grooves",
  "Lofi",
  "Piano",
  "Post Rock",
];

let mentalStateIDs = {
  focus: "6042a1bad80ae028b821e954",
  sleep: "6042a1bad80ae028b821e95c",
  relax: "6042a1bad80ae028b821e958"
}

class DownloadQueue {
  constructor(maxConcurrency) {
    this.queue = [];
    this.activeDownloads = 0;
    this.maxConcurrency = maxConcurrency;
  }

  enqueue(url, folder, filename) {
    this.queue.push({url, folder, filename});
    this.processQueue();
  }

  async processQueue() {
    if (this.activeDownloads < this.maxConcurrency && this.queue.length > 0) {
      const {url, folder, filename} = this.queue.shift();
      this.activeDownloads++;
      await downloadSong(url, folder, filename);
      console.log(`${songCount} songs downloaded successfully \n${this.queue.length} remaining`)
      this.activeDownloads--;
      this.processQueue();
    }
  }
}

const downloadQueue = new DownloadQueue(3)

for(const genre of genres) {
  console.log(chalk.red(`Starting genre ${genre}`))
  for(const mentalState of Object.keys(mentalStateIDs)) {
    console.log(chalk.yellow(`Starting mental state ${mentalState}`))

    // 
    //  Phase 1 : Fetch all song data
    // 
    let data = await fetch(`https://api.brain.fm/v2/genres/${genre}/tracks?mentalStateId=${mentalStateIDs[mentalState]}&version=3`, {
      headers: {
        authorization: `Bearer ${AUTHTOKEN}`
      }
    });
    data = await data.json();

    data = formatAudioData(data.result);

    if (checkIfJsonExists(`./json-data/${mentalState}/${genre}.json`)) continue;
    ensureDirectory(`./json-data/${mentalState}`);
    let file = fs.createWriteStream(`./json-data/${mentalState}/${genre}.json`);

    file.write(JSON.stringify(data));

    file.close();

    // 
    // Phase 2 : Download songs to device
    // 

    console.log(chalk.green(`Started downloading ${genre} ${mentalState}`))
    for (const song of data) {
      let activity = song.serving.track.tags.find(tag => tag.type === "activity").value;
      let NEL = song.neuralEffectLevel;
      let level = (NEL > 0.66 ? "high" : NEL > 0.33 ? "medium" : "low");
      let hasMultipleNELs = song.hasMultipleNELs;

      let folder = `./songs/${genre}/${mentalState}/${activity}/${hasMultipleNELs ? "mixed" : level}`
      let filename = `${song.name.replace(' ', '_')}`;
      let downloadLink = `https://audio.brain.fm/${song.url}?userId=${USERID}&token=${TOKEN}`;

      downloadQueue.enqueue(downloadLink, folder, filename);
    }

  }
};



async function downloadSong(downloadLink, folder, filename) {
  return new Promise((resolve, reject) => {
    ensureDirectory(folder)
    https.get(downloadLink, (response) => {
      response.pipe(fs.createWriteStream(`${folder}/${filename}.mp3`))
        .on('finish', () => {
          songCount++
          resolve();
        })
        .on('error', (error) => {
          console.error('Error downloading song:', error);
          reject(error);
        });
    });
  });
}

function formatAudioData(arr) {
  return arr.map(item => {
    delete item.serving.track.similarTracks;
    return item;
  });
}

function ensureDirectory(directory) {
  if (!fs.existsSync(directory)) {
    fs.mkdirSync(directory, { recursive: true });
  }
}

function checkIfJsonExists(mentalState, genre) {
  const filePath = `./json-data/${mentalState}/${genre}.json`;
  return fs.existsSync(filePath);
}