@use '../../button-toggle/m3-button-toggle';
@use '../../button/m3-button';
@use '../../button/m3-fab';
@use '../../button/m3-icon-button';
@use '../../checkbox/m3-checkbox';
@use '../../chips/m3-chip';
@use '../../expansion/m3-expansion';
@use '../../form-field/m3-form-field';
@use '../../list/m3-list';
@use '../../paginator/m3-paginator';
@use '../../radio/m3-radio';
@use '../../select/m3-select';
@use '../../stepper/m3-stepper';
@use '../../table/m3-table';
@use '../../tabs/m3-tabs';
@use '../../toolbar/m3-toolbar';
@use '../../tree/m3-tree';
@use '../style/elevation';
@use '../theming/config-validation';
@use '../theming/definition';
@use '../theming/inspection';
@use '../theming/m2-inspection';
@use '../theming/palettes';
@use '../style/sass-utils';
@use './m2';
@use './m3';
@use 'sass:list';
@use 'sass:map';
@use 'sass:meta';

/// Emits necessary CSS variables for Material's system level values for the values defined in the
/// config map. The config map can have values color, typography, and/or density.
///
/// If the config map's color value is an Angular Material color palette, it will be used as the
/// primary and tertiary colors with a `color-scheme` theme type. Otherwise if the color value is a
/// map, it must have a `primary` value containing an Angular Material color palette, and
/// optionally a different `tertiary` palette (defaults to primary palette) and `theme-type` that
/// is either `light`, `dark`, or 'color-scheme` (defaults to `color-scheme`). Color variable
/// definitions will not be emitted if there are no color values in the config.
///
/// If the config map's typography value is a font family string, it will be used as the
/// plain and brand font family with default bold, medium, and regular weights of 700, 500, and 400,
/// respectfully. Otherwise if the typography value is a map, it must have a `plain-family` font
/// family value, and optionally a different `brand-family` font family (defaults to the plain
/// value) and weights for `bold-weight` (default: 700), `bold-weight` (default: 500), and
/// `bold-weight` (default: 400). Typography variable definitions will not be emitted if there are
/// no typography values in the config.
///
/// If the config map's density value is a number, it will be used as the density scale. Otherwise
/// if the density value is a map, it must have a `scale` value. Density variable definitions will
/// not be emitted if there are no density values in the config.
///
/// The application variables emitted use the namespace prefix "--mat-sys".
/// e.g. --mat-sys-surface: #E5E5E5
///
/// @param {Map} $config The color configuration with optional keys color, typography, or density.
@mixin theme($config, $overrides: ()) {
  $color: map.get($config, color);
  $color-config: null;
  @if ($color) {
    // validate-palette returns null if it is a valid M3 palette
    $is-palette: config-validation.validate-palette($color) == null;

    // Default to "color-scheme" theme type if the config's color does not provide one.
    @if (not $is-palette and not map.has-key($color, theme-type)) {
      $color: map.set($color, theme-type, color-scheme);
    }

    $color-config: $color;
    @if ($is-palette) {
      $color: map.set($color, tertiary, $color);
      $color-config: (
        definition.$internals: (
          palettes: (
            primary: map.remove($color, neutral, neutral-variant, secondary),
            secondary: map.get($color, secondary),
            tertiary: map.remove($color, neutral, neutral-variant, secondary, error),
            neutral: map.get($color, neutral),
            neutral-variant: map.get($color, neutral-variant),
            error: map.get($color, error),
          ),
          theme-type: color-scheme,
        )
      );
    } @else {
      $primary: map.get($color, primary) or palettes.$violet-palette;
      $tertiary: map.get($color, tertiary) or $primary;
      $color-config: (
        definition.$internals: (
          palettes: (
            primary: map.remove($primary, neutral, neutral-variant, secondary),
            secondary: map.get($primary, secondary),
            tertiary: map.remove($tertiary, neutral, neutral-variant, secondary, error),
            neutral: map.get($primary, neutral),
            neutral-variant: map.get($primary, neutral-variant),
            error: map.get($primary, error),
          ),
          theme-type: map.get($color, theme-type),
        )
      );
    }

    @include system-level-colors($color-config, $overrides, definition.$system-fallback-prefix);
    @include system-level-elevation($color-config, $overrides, definition.$system-fallback-prefix);
  }

  $typography: map.get($config, typography);
  $typography-config: null;
  @if ($typography) {
    $plain: (Roboto, sans-serif);
    $brand: $plain;
    $bold: 700;
    $medium: 500;
    $regular: 400;
    @if (meta.type-of($typography) == map) {
      $plain: map.get($typography, plain-family);
      $brand: map.get($typography, brand-family) or $plain;
      $bold: map.get($typography, bold-weight) or $bold;
      $medium: map.get($typography, medium-weight) or $medium;
      $regular: map.get($typography, regular-weight) or $regular;
    } @else {
      $plain: $typography;
      $brand: $typography;
    }
    $typography-config: (
      definition.$internals: (
        font-definition: (
          plain: $plain,
          brand: $brand,
          bold: $bold,
          medium: $medium,
          regular: $regular,
        )
      )
    );
    @include system-level-typography(
        $typography-config, $overrides, definition.$system-fallback-prefix);
  }

  $density: map.get($config, density);
  $density-config: null;
  @if ($density) {
    $scale: 0;
    @if (meta.type-of($density) == map) {
      $scale: map.get($density, scale);
    } @else {
      $scale: $density;
    }
    @if ($scale != 0) {
      // Emit component-level density tokens if the scale is lower than 0. The density tokens
      // do not fallback to any system-level values and must be defined if the scale is different.
      $density-tokens: get-density-tokens($scale);
      @each $tokens in $density-tokens {
        @each $token-name, $token-value in $tokens {
          --mat-#{$token-name}: #{$token-value};
        }
      }
    }
  }

  @include system-level-shape($overrides: $overrides, $prefix: definition.$system-fallback-prefix);
  @include system-level-state($overrides: $overrides, $prefix: definition.$system-fallback-prefix);
}

// Gets all density-related tokens from the components.
@function get-density-tokens($scale) {
  @return (
    m3-checkbox.get-density-tokens($scale),
    m3-chip.get-density-tokens($scale),
    m3-expansion.get-density-tokens($scale),
    m3-fab.get-density-tokens($scale),
    m3-button.get-density-tokens($scale),
    m3-form-field.get-density-tokens($scale),
    m3-icon-button.get-density-tokens($scale),
    m3-list.get-density-tokens($scale),
    m3-paginator.get-density-tokens($scale),
    m3-radio.get-density-tokens($scale),
    m3-tabs.get-density-tokens($scale),
    m3-select.get-density-tokens($scale),
    m3-button-toggle.get-density-tokens($scale),
    m3-stepper.get-density-tokens($scale),
    m3-table.get-density-tokens($scale),
    m3-toolbar.get-density-tokens($scale),
    m3-tree.get-density-tokens($scale),
  );
}

/// Emits the system-level CSS variables for each of the provided override values. E.g. to
/// change the primary color to red, use `mat.theme-overrides((primary: red));`
@mixin theme-overrides($overrides, $prefix: definition.$system-fallback-prefix) {
  $sys-names: map-merge-all(
      m3.md-sys-color-values-light(palettes.$blue-palette),
      m3.md-sys-typescale-values((
        brand: (Roboto),
        plain: (Roboto),
        bold: 700,
        medium: 500,
        regular: 400
      )),
      m3.md-sys-elevation-values(),
      m3.md-sys-shape-values(),
      m3.md-sys-state-values());

  @include sass-utils.current-selector-or-root {
    @each $name, $value in $overrides {
      @if (map.has-key($sys-names, $name)) {
        --#{$prefix}-#{$name}: #{map.get($overrides, $name)};
      }
    }
  }
}

@mixin system-level-colors($theme, $overrides: (), $prefix: null) {
  $palettes: map.get($theme, definition.$internals, palettes);
  $type: map.get($theme, definition.$internals, theme-type);

  @if (not $prefix) {
    $prefix: map.get($theme, definition.$internals,
        color-system-variables-prefix) or definition.$system-level-prefix;
  }


  $sys-colors: _generate-sys-colors($palettes, $type);

  // Manually insert a subset of palette values that are used directly by components
  // instead of system variables.
  $sys-colors: map.set($sys-colors, neutral-variant20, map.get($palettes, neutral-variant, 20));
  $sys-colors: map.set($sys-colors, neutral10, map.get($palettes, neutral, 10));

  @include sass-utils.current-selector-or-root {
    @each $name, $value in $sys-colors {
      --#{$prefix}-#{$name}: #{map.get($overrides, $name) or $value};
    }
  }
}

@function _generate-sys-colors($palettes, $type) {
  $light-sys-colors: m3.md-sys-color-values-light($palettes);
  @if ($type == light) {
    @return $light-sys-colors;
  }

  $dark-sys-colors: m3.md-sys-color-values-dark($palettes);
  @if ($type == dark) {
    @return $dark-sys-colors;
  }

  @if ($type == color-scheme) {
    $light-dark-sys-colors: ();
    @each $name, $light-value in $light-sys-colors {
      $dark-value: map.get($dark-sys-colors, $name);
      $light-dark-sys-colors:
          map.set($light-dark-sys-colors, $name, light-dark($light-value, $dark-value));
    }
    @return $light-dark-sys-colors;
  }

  @error 'Unknown theme-type provided: #{$type}';
}

@mixin system-level-typography($theme, $overrides: (), $prefix: null) {
  $font-definition: map.get($theme, definition.$internals, font-definition);

  @if (not $prefix) {
    $prefix: map.get($theme, definition.$internals,
        typography-system-variables-prefix) or definition.$system-level-prefix;
  }

  @include sass-utils.current-selector-or-root {
    @each $name, $value in m3.md-sys-typescale-values($font-definition) {
      --#{$prefix}-#{$name}: #{map.get($overrides, $name) or $value};
    }
  }
}

@mixin system-level-elevation($theme, $overrides: (), $prefix: definition.$system-level-prefix) {
  $shadow-color: map.get(
      $theme, definition.$internals, palettes, neutral, 0);

  @include sass-utils.current-selector-or-root {
    @each $name, $value in m3.md-sys-elevation-values() {
      $level: map.get($overrides, $name) or $value;
      $value: elevation.get-box-shadow($level, $shadow-color);
      --#{$prefix}-#{$name}: #{$value};
    }
  }
}

@mixin system-level-shape($theme: (), $overrides: (), $prefix: definition.$system-level-prefix) {
  @include sass-utils.current-selector-or-root {
    @each $name, $value in m3.md-sys-shape-values() {
      --#{$prefix}-#{$name}: #{map.get($overrides, $name) or $value};
    }
  }
}

@mixin system-level-state($theme: (), $overrides: (), $prefix: definition.$system-level-prefix) {
  @include sass-utils.current-selector-or-root {
    @each $name, $value in m3.md-sys-state-values() {
      --#{$prefix}-#{$name}: #{map.get($overrides, $name) or $value};
    }
  }
}

/// Creates a single merged map from the provided variable-length map arguments
@function map-merge-all($maps...) {
  $result: ();
  @each $map in $maps {
    $result: map.merge($result, $map);
  }
  @return $result;
}

// Defines Angular Material system variables using M2 values provided by
// an M2 theme config created with `mat.m2-define-light-theme` or `mat.m2-define-dark-theme`.
//
// This enables applications to style custom components with system-level CSS
// variables instead of creating a separate component theme mixin that relies on
// the theme config.
//
// For example, use `var(--mat-sys-primary)` to get a theme's primary color instead of
// pulling it from the theme with `m2-get-color-from-palette($primary-palette, default)`.
//
// Unlike M3's `mat.theme()`, this mixin does not replace the need to call
// individual component theme mixins for Angular Material components.
@mixin m2-theme($theme-config, $overrides: ()) {
  @if inspection.get-theme-version($theme-config) == 1 {
    @error '`m2-theme` mixin should only be called for M2 theme ' +
        'configs created with define-light-theme or define-dark-theme';
  }

  // Check whether any override keys do not match keys in the theme
  // config system map.
  $invalid-keys: ();
  $config-system: map.get($theme-config, _mat-system);
  @each $key, $value in $overrides {
    @if (not map.has-key($config-system, $key)) {
      $invalid-keys: list.append($invalid-keys, $key);
    }
  }
  @if (list.length($invalid-keys) > 0) {
    @error 'The following overrides are not valid system variables: #{$invalid-keys}. ' +
        'Valid keys are: #{map.keys($config-system)}';
  }

  $config: m2-inspection.get-m2-config($theme-config);

  $color: map.get($config, color);
  @if (m2-inspection.theme-has($theme-config, color)) {
    $system-colors: null;

    @if (map.get($color, is-dark)) {
      $system-colors: m2.md-sys-color-values-dark($color);
    } @else {
      $system-colors: m2.md-sys-color-values-light($color);
    }

    @include _define-m2-system-vars($system-colors, $overrides);

    $shadow: map.get($theme-config, _mat-system, shadow);
    $system-elevations: ();
    @each $name, $value in m2.md-sys-elevation-values() {
      $level: map.get($overrides, $name) or $value;
      $value: elevation.get-box-shadow($level, $shadow);
      $system-elevations: map.set($system-elevations, $name, $value);
    }
    @include _define-m2-system-vars($system-elevations, $overrides);
  }

  $typography: map.get($config, typography);
  @if ($typography) {
    $system-typography: m2.md-sys-typescale-values($typography);
    @include _define-m2-system-vars($system-typography, $overrides);
  }

  @include _define-m2-system-vars(m2.md-sys-shape-values(), $overrides);
  @include _define-m2-system-vars(m2.md-sys-state-values(), $overrides);

  // The icon button's color token is set to `inherit` for M2 and intended to display
  // the color inherited from its parent element. This is crucial because it's unknown
  // whether the icon button sits on a container with background like "surface" or "primary",
  // where both may have different contrast colors like white or black.
  // However, variables set to inherit AND define a fallback will always use the fallback,
  // which is "on-surface-variant". This mixin now defines this value.
  // To avoid this, and continue using `inherit` for the icon button color, set the color explicitly
  // to the token without a fallback.
  .mat-mdc-button-base.mat-mdc-icon-button:not(.mat-mdc-button-disabled) {
    color: var(--mat-icon-button-icon-color);
  }
}

@mixin _define-m2-system-vars($vars, $overrides) {
  @include sass-utils.current-selector-or-root {
    @each $name, $value in $vars {
      --#{definition.$system-fallback-prefix}-#{$name}: #{map.get($overrides, $name) or $value};
    }
  }
}
