//
// Copyright 2026 Google LLC
// SPDX-License-Identifier: Apache-2.0
//

// go/keep-sorted start by_regex='(.+) prefix_order=sass:
@use 'sass:list';
@use 'sass:map';
@use 'sass:meta';
@use 'sass:string';
@use '../../../../../sass/ext/map_ext';
@use '../../../../../tokens/versions/latest/sass/md-ref-typeface';
@use '../../../../../tokens/versions/latest/sass/md-sys-typescale';
@use '../../../../../tokens/versions/latest/sass/md-sys-typescale-emphasized';
@use '../../../../../tokens/versions/latest/sass/md-sys-typescale-emphasized-meta';
@use '../../../../../tokens/versions/latest/sass/md-sys-typescale-meta';
// go/keep-sorted end

@mixin emit-custom-properties(
  $typescale-vars: meta.module-variables(md-sys-typescale),
  $typescale-meta: meta.module-variables(md-sys-typescale-meta),
  $typescale-emphasized-vars: meta.module-variables(md-sys-typescale-emphasized),
  $typescale-emphasized-meta:
    meta.module-variables(md-sys-typescale-emphasized-meta),
  $typeface-vars:
    map.merge(
      meta.module-variables(md-ref-typeface),
      (
        'plain': (
          'Roboto Flex',
          'Roboto',
          'Noto Sans',
          system-ui,
          sans-serif,
        ),
        'brand': var(--md-ref-typeface-plain),
      )
    )
) {
  --md-ref-typeface-brand: #{map_ext.get-strict($typeface-vars, 'brand')};
  --md-ref-typeface-plain: #{map_ext.get-strict($typeface-vars, 'plain')};
  --md-ref-typeface-weight-regular: #{map_ext.get-strict(
      $typeface-vars,
      'weight-regular'
    )};
  --md-ref-typeface-weight-medium: #{map_ext.get-strict(
      $typeface-vars,
      'weight-medium'
    )};
  --md-ref-typeface-weight-bold: #{map_ext.get-strict(
      $typeface-vars,
      'weight-bold'
    )};

  $scales: ('label', 'body', 'title', 'headline', 'display');
  $sizes: (
    'small': 'sm',
    'medium': 'md',
    'large': 'lg',
  );

  @each $scale in $scales {
    @each $long-size, $short-size in $sizes {
      $typescale: '#{$scale}-#{$long-size}';

      $font: _font($typescale, $typescale-vars, $typescale-meta);
      $tracking: map_ext.get-strict($typescale-vars, '#{$typescale}-tracking');
      $axes: _axes($typescale, $typescale-vars);
      $emphasized-font: _font(
        $typescale,
        $typescale-emphasized-vars,
        $typescale-emphasized-meta
      );
      $emphasized-axes: _axes-emphasized(
        $typescale,
        $typescale-emphasized-vars
      );

      --md-sys-typescale-#{$scale}-#{$short-size}: #{$font};
      --md-sys-typescale-#{$scale}-#{$short-size}-tracking: #{$tracking};
      --md-sys-typescale-#{$scale}-#{$short-size}-axes: #{$axes};
      --md-sys-typescale-emphasized-#{$scale}-#{$short-size}: #{$emphasized-font};
      --md-sys-typescale-emphasized-#{$scale}-#{$short-size}-axes: #{$emphasized-axes};
    }
  }
}

/// Returns the `font` shorthand for a typescale from the provided token and
/// metadata variable maps.
@function _font($typescale, $vars, $meta) {
  $weight: map_ext.get-strict($meta, '#{$typescale}-weight--resolved');
  $size: map_ext.get-strict($vars, '#{$typescale}-size');
  $line-height: map_ext.get-strict($vars, '#{$typescale}-line-height');
  $family: map_ext.get-strict($meta, '#{$typescale}-font--resolved');
  @return #{$weight} #{$size} / #{$line-height} #{$family};
}

/// Returns the `font-variation-settings` value for a typescale from the
/// provided token variable map. Returns `normal` if no axes are changed from
/// their default values.
@function _axes($typescale, $vars) {
  $axes: ();
  $axes: _append-axis($axes, map_ext.get-strict($vars, '#{$typescale}-rond'));
  $axes: _append-axis($axes, map_ext.get-strict($vars, '#{$typescale}-grad'));
  @if list.length($axes) == 0 {
    @return normal;
  }
  @return $axes;
}

// TODO: Remove this function once emphasized tokens are fixed to use `'ROND' 100`
@function _axes-emphasized($typescale, $vars) {
  $axes: ();
  $axes: _append-axis($axes, ('ROND' 100));
  $axes: _append-axis($axes, map_ext.get-strict($vars, '#{$typescale}-grad'));
  @return $axes;
}

/// Appends a font axis to a list if it is not the default value for the axis.
@function _append-axis($axes, $axis) {
  // Not all axes from Carbon are supported in gBreeze.
  // - 'opsz': use `font-size`
  // - 'slnt': use `font-style`
  // - 'wdth': use `font-stretch`/`font-width`
  // - 'wght': use `font-weight`
  $default-axes: (
    'ROND': 0,
    'GRAD': 0,
    // These axes are unused in Material, but included for Carbon completeness.
    'CRSV': 0,
    'FILL': 0,
    'HEXP': 0,
  );
  $axis-tag: list.nth($axis, 1);
  $axis-value: list.nth($axis, 2);
  @if not map.has-key($default-axes, $axis-tag) {
    // Do not append unsupported axes.
    @return $axes;
  }
  @if map.get($default-axes, $axis-tag) == $axis-value {
    // Do not append axes with default values.
    @return $axes;
  }

  // Manually add quotes since Sass removes them for custom property values,
  // even with string.quote().
  $axis: '"#{$axis-tag}" #{$axis-value}';
  @return list.append($axes, $axis, $separator: comma);
}