// Copyright (c) roydukkey. All rights reserved.
// Licensed under the MIT. See LICENSE file in the project root for full license information.

@use 'sass:map'
@use 'sass:math'
@use 'sass:meta'
@use '@sass-fairy/exception/src/parameter-type'
@use 'luminance'


$contrast-ratios: ()
$contrast-ratios: map.set($contrast-ratios, 'AA', ('normal': 4.5, 'large': 3))
$contrast-ratios: map.set($contrast-ratios, 'AAA', ('normal': 7, 'large': 4.5))


///
/// @throw `#{$first-color|$second-color}` is not a color.
///
@function contrast($first-color, $second-color)

	@if meta.type-of($first-color) != 'color'
		@error parameter-type.parameter-type('contrast', 'first-color', $first-color, 'color')

	@if meta.type-of($second-color) != 'color'
		@error parameter-type.parameter-type('contrast', 'second-color', $second-color, 'color')

	$first-color: luminance.luminance($first-color) + 0.05
	$second-color: luminance.luminance($second-color) + 0.05

	@return math.div(math.max($first-color, $second-color), math.min($first-color, $second-color))