// Foundation for Sites by ZURB
// foundation.zurb.com
// Licensed under MIT Open Source

////
/// @group functions
////

/// Checks the lightness of `$color`, and if it passes the `$threshold` of lightness, it returns the `$yes` color. Otherwise, it returns the `$no` color. Use this function to dynamically output a foreground color based on a given background color.
///
/// @param {Color} $color - Color to check the lightness of.
/// @param {Color} $yes [$black] - Color to return if `$color` is light.
/// @param {Color} $no [$white] - Color to return if `$color` is dark.
/// @param {Percentage} $threshold [60%] - Threshold of lightness to check against.
///
/// @returns {Color} The $yes color or $no color.
@function foreground($color, $yes: $black, $no: $white, $threshold: 60%) {
  @if $color == transparent {
    $color: $body-background;
  }
  @if (lightness($color) > $threshold) {
    @return $yes;
  }
  @else {
    @return $no;
  }
}

/// Scales a color to be lighter if it's light, or darker if it's dark. Use this function to tint a color appropriate to its lightness.
///
/// @param {Color} $color - Color to scale.
/// @param {Percentage} $scale [5%] - Amount to scale up or down.
/// @param {Percentage} $threshold [40%] - Threshold of lightness to check against.
///
/// @returns {Color} A scaled color.
@function smart-scale($color, $scale: 5%, $threshold: 40%) {
  @if lightness($color) > $threshold {
    $scale: -$scale;
  }
  @return scale-color($color, $lightness: $scale);
}

/// Transfers the colors in the `$foundation-palette` variable into the legacy color variables, such as `$primary-color` and `$secondary-color`. Call this mixin below the Global section of your settings file to properly migrate your codebase.
@mixin add-foundation-colors() {
  @if map-has-key($foundation-palette, primary) {
    $primary-color: map-get($foundation-palette, primary) !global;
  }
  @if map-has-key($foundation-palette, secondary) {
    $secondary-color: map-get($foundation-palette, secondary) !global;
  }
  @if map-has-key($foundation-palette, success) {
    $success-color: map-get($foundation-palette, success) !global;
  }
  @if map-has-key($foundation-palette, warning) {
    $warning-color: map-get($foundation-palette, warning) !global;
  }
  @if map-has-key($foundation-palette, alert) {
    $alert-color: map-get($foundation-palette, alert) !global;
  }
}