export class ColorUtils {
  static hsvToRgb(h, s, v) {
    var r, g, b;

    var i = Math.floor(h * 6);
    var f = h * 6 - i;
    var p = v * (1 - s);
    var q = v * (1 - f * s);
    var t = v * (1 - (1 - f) * s);

    switch (i % 6) {
      case 0:
        (r = v), (g = t), (b = p);
        break;
      case 1:
        (r = q), (g = v), (b = p);
        break;
      case 2:
        (r = p), (g = v), (b = t);
        break;
      case 3:
        (r = p), (g = q), (b = v);
        break;
      case 4:
        (r = t), (g = p), (b = v);
        break;
      case 5:
        (r = v), (g = p), (b = q);
        break;
    }

    return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
  }

  static rgbToHsv(r, g, b) {
    (r = r / 255), (g = g / 255), (b = b / 255);
    var max = Math.max(r, g, b),
      min = Math.min(r, g, b);
    var h,
      s,
      v = max;

    var d = max - min;
    s = max == 0 ? 0 : d / max;

    if (max == min) {
      h = 0; // achromatic
    } else {
      switch (max) {
        case r:
          h = (g - b) / d + (g < b ? 6 : 0);
          break;
        case g:
          h = (b - r) / d + 2;
          break;
        case b:
          h = (r - g) / d + 4;
          break;
      }
      h /= 6;
    }

    return [h, s, v];
  }
}