import { getAudioContext } from './superdough.mjs';

// https://github.com/KilledByAPixel/ZzFX/blob/master/ZzFX.js#L85C5-L180C6
// changes: replaced this.volume with 1 + using sampleRate from getAudioContext()
export function buildSamples(
  volume = 1,
  randomness = 0.05,
  frequency = 220,
  attack = 0,
  sustain = 0,
  release = 0.1,
  shape = 0,
  shapeCurve = 1,
  slide = 0,
  deltaSlide = 0,
  pitchJump = 0,
  pitchJumpTime = 0,
  repeatTime = 0,
  noise = 0,
  modulation = 0,
  bitCrush = 0,
  delay = 0,
  sustainVolume = 1,
  decay = 0,
  tremolo = 0,
) {
  // init parameters
  let PI2 = Math.PI * 2,
    sampleRate = getAudioContext().sampleRate,
    sign = (v) => (v > 0 ? 1 : -1),
    startSlide = (slide *= (500 * PI2) / sampleRate / sampleRate),
    startFrequency = (frequency *= ((1 + randomness * 2 * Math.random() - randomness) * PI2) / sampleRate),
    b = [],
    t = 0,
    tm = 0,
    i = 0,
    j = 1,
    r = 0,
    c = 0,
    s = 0,
    f,
    length;

  // scale by sample rate
  attack = attack * sampleRate + 9; // minimum attack to prevent pop
  decay *= sampleRate;
  sustain *= sampleRate;
  release *= sampleRate;
  delay *= sampleRate;
  deltaSlide *= (500 * PI2) / sampleRate ** 3;
  modulation *= PI2 / sampleRate;
  pitchJump *= PI2 / sampleRate;
  pitchJumpTime *= sampleRate;
  repeatTime = (repeatTime * sampleRate) | 0;

  // generate waveform
  for (length = (attack + decay + sustain + release + delay) | 0; i < length; b[i++] = s) {
    if (!(++c % ((bitCrush * 100) | 0))) {
      // bit crush
      s = shape
        ? shape > 1
          ? shape > 2
            ? shape > 3 // wave shape
              ? Math.sin((t % PI2) ** 3) // 4 noise
              : Math.max(Math.min(Math.tan(t), 1), -1) // 3 tan
            : 1 - (((((2 * t) / PI2) % 2) + 2) % 2) // 2 saw
          : 1 - 4 * Math.abs(Math.round(t / PI2) - t / PI2) // 1 triangle
        : Math.sin(t); // 0 sin

      s =
        (repeatTime
          ? 1 - tremolo + tremolo * Math.sin((PI2 * i) / repeatTime) // tremolo
          : 1) *
        sign(s) *
        Math.abs(s) ** shapeCurve * // curve 0=square, 2=pointy
        volume *
        1 * // envelope
        (i < attack
          ? i / attack // attack
          : i < attack + decay // decay
          ? 1 - ((i - attack) / decay) * (1 - sustainVolume) // decay falloff
          : i < attack + decay + sustain // sustain
          ? sustainVolume // sustain volume
          : i < length - delay // release
          ? ((length - i - delay) / release) * // release falloff
            sustainVolume // release volume
          : 0); // post release

      s = delay
        ? s / 2 +
          (delay > i
            ? 0 // delay
            : ((i < length - delay ? 1 : (length - i) / delay) * // release delay
                b[(i - delay) | 0]) /
              2)
        : s; // sample delay
    }

    f =
      (frequency += slide += deltaSlide) * // frequency
      Math.cos(modulation * tm++); // modulation
    t += f - f * noise * (1 - (((Math.sin(i) + 1) * 1e9) % 2)); // noise

    if (j && ++j > pitchJumpTime) {
      // pitch jump
      frequency += pitchJump; // apply pitch jump
      startFrequency += pitchJump; // also apply to start
      j = 0; // stop pitch jump time
    }

    if (repeatTime && !(++r % repeatTime)) {
      // repeat
      frequency = startFrequency; // reset frequency
      slide = startSlide; // reset slide
      j ||= 1; // reset pitch jump time
    }
  }

  return b;
}
