@use 'sass:map';
@use 'sass:math';
@use 'sass:meta';
@use 'variables';


// A collection of mixins and CSS classes that can be used to apply elevation to a material
// element.
// See: https://material.io/design/environment/elevation.html
// Examples:
//
//
// .mat-foo {
//   @include $mat-elevation(2);
//
//   &:active {
//     @include $mat-elevation(8);
//   }
// }
//
// <div id="external-card" class="mat-elevation-z2"><p>Some content</p></div>
//
// For an explanation of the design behind how elevation is implemented, see the design doc at
// https://goo.gl/Kq0k9Z.

// Colors for umbra, penumbra, and ambient shadows. As described in the design doc, each elevation
// level is created using a set of 3 shadow values, one for umbra (the shadow representing the
// space completely obscured by an object relative to its light source), one for penumbra (the
// space partially obscured by an object), and one for ambient (the space which contains the object
// itself). For a further explanation of these terms and their meanings, see
// https://en.wikipedia.org/wiki/Umbra,_penumbra_and_antumbra.

// Maps for the different shadow sets and their values within each z-space. These values were
// created by taking a few reference shadow sets created by Google's Designers and interpolating
// all of the values between them.

@function _get-umbra-map($color, $opacity) {
  $shadow-color: if(meta.type-of($color) == color, rgba($color, $opacity * 0.2), $color);

  @return (
    0: '0px 0px 0px 0px #{$shadow-color}',
    1: '0px 2px 1px -1px #{$shadow-color}',
    2: '0px 3px 1px -2px #{$shadow-color}',
    3: '0px 3px 3px -2px #{$shadow-color}',
    4: '0px 2px 4px -1px #{$shadow-color}',
    5: '0px 3px 5px -1px #{$shadow-color}',
    6: '0px 3px 5px -1px #{$shadow-color}',
    7: '0px 4px 5px -2px #{$shadow-color}',
    8: '0px 5px 5px -3px #{$shadow-color}',
    9: '0px 5px 6px -3px #{$shadow-color}',
    10: '0px 6px 6px -3px #{$shadow-color}',
    11: '0px 6px 7px -4px #{$shadow-color}',
    12: '0px 7px 8px -4px #{$shadow-color}',
    13: '0px 7px 8px -4px #{$shadow-color}',
    14: '0px 7px 9px -4px #{$shadow-color}',
    15: '0px 8px 9px -5px #{$shadow-color}',
    16: '0px 8px 10px -5px #{$shadow-color}',
    17: '0px 8px 11px -5px #{$shadow-color}',
    18: '0px 9px 11px -5px #{$shadow-color}',
    19: '0px 9px 12px -6px #{$shadow-color}',
    20: '0px 10px 13px -6px #{$shadow-color}',
    21: '0px 10px 13px -6px #{$shadow-color}',
    22: '0px 10px 14px -6px #{$shadow-color}',
    23: '0px 11px 14px -7px #{$shadow-color}',
    24: '0px 11px 15px -7px #{$shadow-color}'
  );
}

@function _get-penumbra-map($color, $opacity) {
  $shadow-color: if(meta.type-of($color) == color, rgba($color, $opacity * 0.14), $color);

  @return (
    0: '0px 0px 0px 0px #{$shadow-color}',
    1: '0px 1px 1px 0px #{$shadow-color}',
    2: '0px 2px 2px 0px #{$shadow-color}',
    3: '0px 3px 4px 0px #{$shadow-color}',
    4: '0px 4px 5px 0px #{$shadow-color}',
    5: '0px 5px 8px 0px #{$shadow-color}',
    6: '0px 6px 10px 0px #{$shadow-color}',
    7: '0px 7px 10px 1px #{$shadow-color}',
    8: '0px 8px 10px 1px #{$shadow-color}',
    9: '0px 9px 12px 1px #{$shadow-color}',
    10: '0px 10px 14px 1px #{$shadow-color}',
    11: '0px 11px 15px 1px #{$shadow-color}',
    12: '0px 12px 17px 2px #{$shadow-color}',
    13: '0px 13px 19px 2px #{$shadow-color}',
    14: '0px 14px 21px 2px #{$shadow-color}',
    15: '0px 15px 22px 2px #{$shadow-color}',
    16: '0px 16px 24px 2px #{$shadow-color}',
    17: '0px 17px 26px 2px #{$shadow-color}',
    18: '0px 18px 28px 2px #{$shadow-color}',
    19: '0px 19px 29px 2px #{$shadow-color}',
    20: '0px 20px 31px 3px #{$shadow-color}',
    21: '0px 21px 33px 3px #{$shadow-color}',
    22: '0px 22px 35px 3px #{$shadow-color}',
    23: '0px 23px 36px 3px #{$shadow-color}',
    24: '0px 24px 38px 3px #{$shadow-color}'
  );
}

@function _get-ambient-map($color, $opacity) {
  $shadow-color: if(meta.type-of($color) == color, rgba($color, $opacity * 0.12), $color);

  @return (
    0: '0px 0px 0px 0px #{$shadow-color}',
    1: '0px 1px 3px 0px #{$shadow-color}',
    2: '0px 1px 5px 0px #{$shadow-color}',
    3: '0px 1px 8px 0px #{$shadow-color}',
    4: '0px 1px 10px 0px #{$shadow-color}',
    5: '0px 1px 14px 0px #{$shadow-color}',
    6: '0px 1px 18px 0px #{$shadow-color}',
    7: '0px 2px 16px 1px #{$shadow-color}',
    8: '0px 3px 14px 2px #{$shadow-color}',
    9: '0px 3px 16px 2px #{$shadow-color}',
    10: '0px 4px 18px 3px #{$shadow-color}',
    11: '0px 4px 20px 3px #{$shadow-color}',
    12: '0px 5px 22px 4px #{$shadow-color}',
    13: '0px 5px 24px 4px #{$shadow-color}',
    14: '0px 5px 26px 4px #{$shadow-color}',
    15: '0px 6px 28px 5px #{$shadow-color}',
    16: '0px 6px 30px 5px #{$shadow-color}',
    17: '0px 6px 32px 5px #{$shadow-color}',
    18: '0px 7px 34px 6px #{$shadow-color}',
    19: '0px 7px 36px 6px #{$shadow-color}',
    20: '0px 8px 38px 7px #{$shadow-color}',
    21: '0px 8px 40px 7px #{$shadow-color}',
    22: '0px 8px 42px 7px #{$shadow-color}',
    23: '0px 9px 44px 8px #{$shadow-color}',
    24: '0px 9px 46px 8px #{$shadow-color}'
  );
}

// The default duration value for elevation transitions.
$transition-duration: 280ms !default;

// The default easing value for elevation transitions.
$transition-timing-function: variables.$fast-out-slow-in-timing-function;

// The default color for elevation shadows.
$color: black !default;

// The default opacity scaling value for elevation shadows.
$opacity: 1 !default;

// Prefix for elevation-related selectors.
$prefix: 'mat-elevation-z';

// Applies the correct css rules to an element to give it the elevation specified by $zValue.
// The $zValue must be between 0 and 24.
@mixin elevation($zValue, $color: $color, $opacity: $opacity) {
  @if meta.type-of($zValue) != number or not math.is-unitless($zValue) {
    @error '$zValue must be a unitless number';
  }
  @if $zValue < 0 or $zValue > 24 {
    @error '$zValue must be between 0 and 24';
  }

  box-shadow: #{map.get(_get-umbra-map($color, $opacity), $zValue)},
              #{map.get(_get-penumbra-map($color, $opacity), $zValue)},
              #{map.get(_get-ambient-map($color, $opacity), $zValue)};
}

// Applies the elevation to an element in a manner that allows
// consumers to override it via the Material elevation classes.
@mixin overridable-elevation(
    $zValue,
    $color: $color,
    $opacity: $opacity) {
  &:not([class*='#{$prefix}']) {
    @include elevation($zValue, $color, $opacity);
  }
}

// Returns a string that can be used as the value for a transition property for elevation.
// Calling this function directly is useful in situations where a component needs to transition
// more than one property.
//
// .foo {
//   transition: mat-elevation-transition-property-value(), opacity 100ms ease;
// }
@function private-transition-property-value(
    $duration: $transition-duration,
    $easing: $transition-timing-function) {
  @return box-shadow #{$duration} #{$easing};
}

// Applies the correct css rules needed to have an element transition between elevations.
// This mixin should be applied to elements whose elevation values will change depending on their
// context (e.g. when active or disabled).
//
// NOTE(traviskaufman): Both this mixin and the above function use default parameters so they can
// be used in the same way by clients.
@mixin elevation-transition(
    $duration: $transition-duration,
    $easing: $transition-timing-function) {
  transition: private-transition-property-value($duration, $easing);
}
