@use 'sass:color';
@use 'sass:math';
@use 'sass:map';
@use 'sass:list';
@use 'sass:meta';

@use 'iro-sass/src/iro-sass' as iro;
@use 'iro-sass/src/easing';
@use 'apca';
@use 'themes';

@function palette($base-color, $contrasts, $chroma-range: 1, $ref-color: $base-color) {
    $base-lch: color.to-space($base-color, oklch);
    $ref-lch: color.to-space($ref-color, oklch);

    $ref-l: color.channel($ref-lch, 'lightness');
    $ref-y: apca.sRGB_to_Y($ref-lch);

    $cmax: math.max(map.values($contrasts)...);
    $cmax: math.max($cmax, math.abs(math.min(map.values($contrasts)...)));

    $black-y: apca.sRGB_to_Y(#000);
    $white-y: apca.sRGB_to_Y(#fff);

    $chroma-inv: false;
    @if $chroma-range < 0 {
        $chroma-inv: true;
        $chroma-range: -1 * $chroma-range;
    }
    $chroma-easing: meta.get-function(themes.$palette-chroma-easing, $module: easing);

    $palette: ();

    @each $key, $contrast in $contrasts {
        $y: apca.reverse($contrast, $ref-y);
        $l: color.channel($base-lch, 'lightness');
        $c: 1;

        @if $y != false {
            $l: color.channel(apca.Y_to_sRGB($y), 'lightness', oklch);
        } @else {
            $y: $ref-y;
        }

        @if $chroma-range != 1 {
            $c: if($ref-l > 50%, math.clamp(0, math.div($contrast, $cmax), 1), -1 * math.clamp(-1, math.div($contrast, $cmax), 0));
            @if $chroma-inv {
                $c: 1 - $c;
            }
            $c: meta.call($chroma-easing, $c);
            $c: $chroma-range + (1 - $chroma-range) * $c;
        }

        $color: oklch($l ($c * color.channel($base-lch, 'chroma')) color.channel($base-lch, 'hue'));

        $contrast-black: apca.contrast($black-y, $y);
        $contrast-white: apca.contrast($white-y, $y);

        $palette: map.set($palette, $key, $color);
        $palette: map.set($palette, #{$key}-text, if(math.abs($contrast-black) > math.abs($contrast-white), #000, #fff));
    }

    @return $palette;
}

@function transparent-palette($color, $text, $alphas) {
    $palette: (
        --text: $text,
    );

    @each $key, $alpha in $alphas {
        $palette: map.set($palette, $key, rgba($color, $alpha));
    }

    @return $palette;
}

@function px-to-em($size, $base: iro.$vars-root-size) {
    @return math.div($size, $base) * 1em;
}