@use "sass:math";
@use "sass:color";
@use "sass:meta";
@use "sass:map";

@function powerNumber($number, $exp) {
  $value: 1;

  @if $exp > 0 {
    @for $i from 1 through $exp {
      $value: $value * $number;
    }
  }

  @else if $exp < 0 {
    @for $i from 1 through -$exp {
      $value: math.div($value, $number);
    }
  }

  @return $value;
}

@function colorLuminance($color) {
  @if meta.type-of($color) != "color" {
    @return 0.55;
  }

  $color-rgb: (
    'red': color.channel($color, "red", $space: rgb),
    'green': color.channel($color, "green", $space: rgb),
    'blue': color.channel($color, "blue", $space: rgb)
  );

  @each $name, $value in $color-rgb {
    $value: math.div($value, 255);

    @if $value < 0.03928 {
      $value: math.div($value, 12.92);
    }

    @else {
      $value: math.div($value + 0.055, 1.055);
      $value: powerNumber($value, 2);
    }

    $color-rgb: map.merge($color-rgb, ($name: $value));
  }

  @return (map.get($color-rgb, 'red') * .2126) + (map.get($color-rgb, 'green') * .7152) + (map.get($color-rgb, 'blue') * .0722);
}

@function findColorInvert($color) {
  @if (colorLuminance($color) > 0.55) {
    @return rgba(#000, 0.7);
  }

  @else {
    @return #fff;
  }
}

@function findLightColor($color) {
  @if meta.type-of($color) == "color" {
    $l: 96%;

    @if color.channel($color, "lightness", $space: hsl) > 96% {
      $l: color.channel($color, "lightness", $space: hsl);
    }

    @return color.change($color, $lightness: $l);
  }

  @return $color;
}

@function findDarkColor($color) {
  @if meta.type-of($color) == "color" {
    $base-l: 29%;
    $current-l: color.channel($color, "lightness", $space: hsl);
    $luminance: colorLuminance($color);
    $luminance-delta: (
      0.53 - $luminance
    );
    $target-l: math.round($base-l + ($luminance-delta * 53));

    // Use the darker of: calculated target or original lightness.
    @return color.change($color, $lightness: min($current-l, max($base-l, $target-l)));
  }

  @return $color;
}

@function bulmaRgba($color, $alpha) {
  @if meta.type-of($color) != "color" {
    @return $color;
  }

  @return color.change($color, $alpha: $alpha);
}

@function bulmaDarken($color, $amount) {
  @if meta.type-of($color) != "color" {
    @return $color;
  }

  @return color.adjust($color, $lightness: -$amount);
}

@function bulmaLighten($color, $amount) {
  @if meta.type-of($color) != "color" {
    @return $color;
  }

  @return color.adjust($color, $lightness: $amount);
}