const sampleOffset = 1200; // So the beep lands accurately
let frkk = null;
let linenoise = null;
let introcall = null;

class Audio {
  constructor (settingsObj) {
    this.settingsObj = settingsObj;
    this.init();
    this.promiseResolve = null;
    this.promiseReject = null;
    this.loaded = new Promise((resolve, reject) => {
      this.promiseResolve = resolve;
      this.promiseReject = reject;
    });
  }
  async init() {
    // Set up web audio
    const AudioCtx = window.AudioContext || window.webkitAudioContext;
    this.ctx = new AudioCtx;
    // Load file
    this.audioBuffer = await this.getFile();
  }
  async getFile() {
    // Request file
    const response = await fetch(this.settingsObj.src);
    if (!response.ok) {
      console.log(`${response.url} ${response.statusText}`);
      this.promiseReject();
      throw new Error(`${response.url} ${response.statusText}`);
    }
    const arrayBuffer = await response.arrayBuffer();
    const audioBuffer = await this.ctx.decodeAudioData(arrayBuffer);
    this.promiseResolve();
    return audioBuffer;
  }
}

class Sound extends Audio {
  constructor (settingsObj) {
    super(settingsObj);
  }
  play () {
    let sampleSource = this.ctx.createBufferSource();
    sampleSource.buffer = this.audioBuffer;
    sampleSource.connect(this.ctx.destination);
    sampleSource.addEventListener('ended', () => {
      if (this.cb) this.cb();
    })
    sampleSource.start();
  }
  onEnded (cb) {
    this.cb = cb;
  }
}

class Loop extends Audio {
  constructor (settingsObj) {
    super(settingsObj);
    this.playing = [];
  }
  play () {
    console.log('play');
    let sampleSource = this.ctx.createBufferSource();
    sampleSource.buffer = this.audioBuffer;
    sampleSource.connect(this.ctx.destination);
    sampleSource.start();
    this.stop();
    this.playing.push(sampleSource);
    setTimeout(this.play.bind(this), this.settingsObj.looptime);
  }
  stop() {
    console.log('stop', this.playing);
    this.playing.forEach(sampleSource => {
      sampleSource.stop(this.ctx.currentTime + 0.1); // Adding .1 second to ensure overlap
    });
    this.playing = [];
  }
}

class Sprite extends Audio {
  constructor(settingsObj) {
    super(settingsObj);
    this.playing = [];
  }
  play(sampleName) {
    const startTime = this.settingsObj.sprite[sampleName][0] / 1000;
    const duration = this.settingsObj.sprite[sampleName][1] / 1000;
    const sampleSource = this.ctx.createBufferSource();
    sampleSource.buffer = this.audioBuffer;
    sampleSource.connect(this.ctx.destination);
    this.playing.push(sampleSource);
    sampleSource.start(this.ctx.currentTime, startTime, duration);
    sampleSource.addEventListener('ended', () => {
      this.playing.splice(this.playing.indexOf(sampleSource), 1);
      console.log('sample ended');
    });
  }
}

const tenSecondsInTheFuture = (dateObj) => {
  return new Date(dateObj.getTime() + 10000);
}

const nearestWholeTenSeconds = (dateObj) => {
  return new Date(Math.round(dateObj.getTime() / 10000) * 10000);
}

const nearestWholeTenSecondsInTheFuture = (dateObj) => {
  let nearest = nearestWholeTenSeconds(dateObj);
  return nearest <= dateObj ? tenSecondsInTheFuture(nearest) : nearest;
}

const dateToSamples = (dateObj) => {
  let h = dateObj.getHours();
  return [
    h < 10 ? `h${h}` : `m${h}`,
    `m${dateObj.getMinutes()}`,
    `s${dateObj.getSeconds()}`,
    'b'
  ];
}

const calcTimeDiff = (a, b) => {
  return b.getTime() - a.getTime();
}

const clickHandler = (evt) => {
  const button = document.querySelector('.main-button button');
  button.classList.add('off');
  introcall.onEnded(mainLoop);
  introcall.play();
  frkk.play('n');
  linenoise.play(); // Have to play something to claim audio privileges
}

const scheduleSamples = (next, samples = []) => {
  if (samples.length === 0) return;
  let offset = (calcTimeDiff(new Date(), next) - samples.length * 2000);
  if (offset < 0) {
    scheduleSamples(next, samples.slice(1));
    return;
  } else {
    setTimeout(() => {
      frkk.play(samples[0]);
    }, offset);
    scheduleSamples(next, samples.slice(1));
  }
}

const mainLoop = () => {
  let now = new Date();
  let next = nearestWholeTenSecondsInTheFuture(now);
  let samples = dateToSamples(next);
  console.log(samples);
  scheduleSamples(new Date(next.getTime() + sampleOffset), samples);
  let diff = next.getTime() - now.getTime();
  setTimeout(() => {
    mainLoop();
  }, diff);
}

const init = () => {
  const spriteData = {'src': './audio/frkk.mp3', 'sprite': {}};
  for (let i = 0; i < 78; i++) {
    let name = i<10 ? `h${i}` : i<70 ? `m${i-10}` : i<76 ? `s${(i-70)*10}` : i<77 ? `b` : `n`;
    let timing = [i*2000, 2000];
    spriteData.sprite[name] = timing;
  }
  frkk = new Sprite(spriteData);
  linenoise = new Loop({'src': './audio/linenoise.mp3', 'looptime': 9000});
  introcall = new Sound({'src': './audio/call.mp3'});

  Promise.all([frkk.loaded, linenoise.loaded, introcall.loaded]).then(() => {
    console.log('all loaded');
    const button = document.querySelector('.main-button button');
    button.addEventListener('click', clickHandler);
    button.classList.remove('off');
  });
}

window.addEventListener('DOMContentLoaded', init);