@use 'sass:color';
@use 'sass:math';
@use 'sass:meta';
@use 'sass:string';

/// Takes a given color in virtually any notation and converts it into CMYK
/// notation using the [ device-cmyk() ] CSS color function.
///
/// @param {Color} $color - The color to convert into cmyk.
///
/// @return {Color} The converted color in [ device-cmyk() ] function format.
///
/// @access public
/// @group Utilities
///
/// @throw Invalid $color data type error, must be of type 'color'.
@function to-cmyk($color) {
  @if meta.type-of($color) != 'color' {
    @error 'Invalid data type passed to [ to-cmyk() ] function. You passed ' +
      '[ #{$color} ] for the $color argument, which is not a ' +
      'a color that can be converted by this function.';
  }

  // Convert color to RGB, as Sass works natively with RGB values
  $red-component: math.div(color.red($color), 255);
  $green-component: math.div(color.green($color), 255);
  $blue-component: math.div(color.blue($color), 255);
  $alpha-component: color.alpha($color);

  // Find the minimum of the RGB components
  $k: 1 - max($red-component, $green-component, $blue-component);

  // Avoid division by zero
  $c: if($k < 1, math.div((1 - $red-component - $k), (1 - $k)), 0);
  $m: if($k < 1, math.div((1 - $green-component - $k), (1 - $k)), 0);
  $y: if($k < 1, math.div((1 - $blue-component - $k), (1 - $k)), 0);

  // Convert to percentages
  $c: math.round($c * 100) * 1%;
  $m: math.round($m * 100) * 1%;
  $y: math.round($y * 100) * 1%;
  $k: math.round($k * 100) * 1%;

  // backup rgb values
  $r: color.red($color);
  $g: color.green($color);
  $b: color.blue($color);

  @if $alpha-component < 1 {
    @return #{'device-cmyk(#{$c} #{$m} #{$y} #{$k} / #{$alpha-component}, ' +
      'rgb(#{$r} #{$g} #{$b} / #{$alpha-component}))'};
  } @else {
    @return #{'device-cmyk(#{$c} #{$m} #{$y} #{$k}, rgb(#{$r} #{$g} #{$b}))'};
  }
}