@use 'sass:list';
@use 'sass:math';
@use 'sass:string';
@use '../../math/get-numeric/get-numeric.scss' as *;
@use '../../math/with-unit/with-unit.scss' as *;
@use '../../string/str-split/str-split.scss' as *;

/**
 * Generates a value or expression that allows to set a size
 * exactly equalled a given number of layout columns.
 *
 * @param    {string}     $expression       An expression describing the needed number of layout columns to fill: `needed-columns/total-columns`.
 * @param    {?number}    $gutter [null]    Space between layout columns.
 *
 * @return   {string|number}    Calc expression or exact value.
 */
@function column($expression, $gutter: null) {
	$expression: #{$expression};
	$parsed: str-split($expression, '/');

	$columns: get-numeric(list.nth($parsed, 1));
	$total: get-numeric(list.nth($parsed, 2));

	@if ($gutter) {
		@return string.unquote('calc(100% / #{math.div($total, $columns)} - (#{with-unit($gutter)} * (#{$total} - #{$columns}) / #{$total}))');
	}

	@return math.div(100, math.div($total, $columns)) * 1%;
}