@import "bezierEasing";
@import "tinyColor";

.colorPaletteMixin() {
  @functions: ~`(function() {
    var hueStep = 2;
    var saturationStep = 16;
    var saturationStep2 = 5;
    var brightnessStep1 = 5;
    var brightnessStep2 = 15;
    var lightColorCount = 5;
    var darkColorCount = 4;

    var getHue = function(hsv, i, isLight) {
      var hue;

      if (hsv.h >= 60 && hsv.h <= 240) {
        hue = isLight ? hsv.h - hueStep * i : hsv.h + hueStep * i;
      } else {
        hue = isLight ? hsv.h + hueStep * i : hsv.h - hueStep * i;
      }

      if (hue < 0) {
        hue += 360;
      } else if (hue >= 360) {
        hue -= 360;
      }

      return Math.round(hue);
    };

    var getSaturation = function(hsv, i, isLight) {
      var saturation;

      if (isLight) {
        saturation = Math.round(hsv.s * 100) - saturationStep * i;
      } else if (i === darkColorCount) {
        saturation = Math.round(hsv.s * 100) + saturationStep;
      } else {
        saturation = Math.round(hsv.s * 100) + saturationStep2 * i;
      }

      if (saturation > 100) {
        saturation = 100;
      }

      if (isLight && i === lightColorCount && saturation > 10) {
        saturation = 10;
      }

      if (saturation < 6) {
        saturation = 6;
      }

      return Math.round(saturation);
    };

    var getValue = function(hsv, i, isLight) {
      if (isLight) {
        return Math.round(hsv.v * 100) + brightnessStep1 * i;
      }

      return Math.round(hsv.v * 100) - brightnessStep2 * i;
    };

    this.colorPalette = function(color, index) {
      var isLight = index <= 6;
      var hsv = tinycolor(color).toHsv();
      var i = isLight ? lightColorCount + 1 - index : index - lightColorCount - 1;
      var value = {
        h: getHue(hsv, i, isLight),
        s: getSaturation(hsv, i, isLight),
        v: getValue(hsv, i, isLight)
      };

      return tinycolor(value).toHexString();
    };
  })()`;
}

.colorPaletteMixin();