@use 'sass:list';
@use 'sass:math';
@use '../../math/strip-unit/strip-unit.scss' as *;

/**
 * Returns a value scaling uniformly within the specified viewport limits.
 *
 * @param    {list}    $start    The list containing start values of screen width and property.
 * @param    {list}    $end      The list containing end values of screen width and property.
 *
 * @return   {?number}        Fluid value or single fixed value.
 */
@function use-fluid-value($start, $end) {
	$start-vw: list.nth($start, 1);
	$start-val: list.nth($start, 2);
	$end-vw: list.nth($end, 1);
	$end-val: list.nth($end, 2);

	@if ($start-val != null and $end-val == null) {
		@return $start-val;
	}

	@if ($end-val != null and $start-val == null) {
		@return $end-val;
	}

	@if ($start-val == null and $end-val == null) {
		@return null;
	}

	@if ($start-val == $end-val) {
		@return $start-val;
	}

	$min-val: math.min($start-val, $end-val);
	$max-val: math.max($start-val, $end-val);
	$vw-diff: strip-unit($end-vw - $start-vw);
	$val-diff: strip-unit($end-val - $start-val);
	$fluid-val: calc($start-val + $val-diff * (100vi - #{$start-vw}) / $vw-diff);

	@return clamp($min-val, $fluid-val, $max-val);
}