// /*------------------------------------*\
//     #LINE-HEIGHT
// \*------------------------------------*/

@use "sass:math";
@use "../settings/settings.config" as *;
@use "tools.utils" as *;

/// Helper function to calculate a `rem`-unit line-height based on a given
/// Modular Scale entity, the font-size ratio and the
/// `$GLOBAL-BASELINE`.
///
/// @access private
///
/// @param {integer} $scale - Choose a scale value that is defined under
///   `scales` in `$CONFIG`.
/// @param {number} $ratio - The Modular Scale ratio.
///
/// @example scss
///     .foo {
///         line-height: fluidms-line-height(3, 1.25);
///     }
///
/// @return {length (in `rem`)} Outputs a `rem` value that is a multiple of
///   our `$GLOBAL-BASELINE`.
@function fluidms-line-height($scale, $ratio) {
    $_optimal-line-height: $GLOBAL-LINE-HEIGHT;
    @if $GLOBAL-BASELINE {
        // Calculate the default line-height (in `rem`).
        $_default-line-height: (math.pow($ratio, $scale)) * (math.div($GLOBAL-LINE-HEIGHT, math.pow($GLOBAL-LINE-HEIGHT-RATIO, $scale)));
        // Get the “offset” of the vertical grid.
        $_remainder: $_default-line-height;
        @while ($_remainder >= fluidms-strip-unit($GLOBAL-BASELINE)) {
            $_remainder: $_remainder - $GLOBAL-BASELINE;
        }
        // Subtract the “offset” so we stay in the exact vertical grid.
        $_optimal-line-height: $_default-line-height - $_remainder;
    }

    @return $_optimal-line-height;
}