@use 'sass:map';
@use 'sass:meta';
@use '@angular/cdk';
@use '../style/layout-common';
@use '../theming/theming';
@use '../theming/inspection';

// Private sass variables that will be used as reference throughout component stylesheets.
$default-border-width: 3px;
$default-border-style: solid;
$default-border-color: transparent;
$default-border-radius: 4px;

// Mixin that renders the focus indicator structural styles.
@mixin structural-styling($prefix) {
  .#{$prefix}-focus-indicator {
    position: relative;

    &::before {
      @include layout-common.fill();
      box-sizing: border-box;
      pointer-events: none;
      display: var(--#{$prefix}-focus-indicator-display, none); // Hide the indicator by default.
      border: var(
          --#{$prefix}-focus-indicator-border-width,
          #{$default-border-width}
        )
        var(
          --#{$prefix}-focus-indicator-border-style,
          #{$default-border-style}
        )
        var(
          --#{$prefix}-focus-indicator-border-color,
          #{$default-border-color}
        );
      border-radius: var(
        --#{$prefix}-focus-indicator-border-radius,
        #{$default-border-radius}
      );
    }

    // By default, render the focus indicator when the focus indicator host element takes focus.
    // Defining a pseudo element's content will cause it to render.
    &:focus::before {
      content: '';
    }
  }

  // Enable the indicator in high contrast mode.
  @include cdk.high-contrast(active, off) {
    @include customize-focus-indicators((display: block), $prefix);
  }
}

// Generates CSS variable declarations from a map.
@mixin _output-variables($map) {
  @each $key, $value in $map {
    @if ($value) {
      --#{$key}: #{$value};
    }
  }
}

// Mixin that dedups CSS variables for the strong-focus-indicators mixin.
@mixin customize-focus-indicators($config, $prefix) {
  $border-style: map.get($config, border-style);
  $border-width: map.get($config, border-width);
  $border-radius: map.get($config, border-radius);
  $border-color: map.get($config, border-color);
  $display: map.get($config, display);
  $map: (
    '#{$prefix}-focus-indicator-border-style': $border-style,
    '#{$prefix}-focus-indicator-border-width': $border-width,
    '#{$prefix}-focus-indicator-border-radius': $border-radius,
    '#{$prefix}-focus-indicator-border-color': $border-color,
    '#{$prefix}-focus-indicator-display': $display,
  );

  @if (&) {
    @include _output-variables($map);
  }
  @else {
    // We use `html` here instead of `:root`, because the
    // latter causes some issues with internal tooling.
    html {
      @include _output-variables($map);
    }
  }
}

@mixin strong-focus-indicators($config: ()) {
  // Default focus indicator config.
  $default-config: (
      border-color: black,
      display: block,
  );

  // Merge default config with user config.
  $config: map.merge($default-config, $config);

  @include customize-focus-indicators($config, 'mat');
}

@mixin mdc-strong-focus-indicators($config: ()) {
  // Default focus indicator config.
  $default-config: (
      border-color: black,
      display: block,
  );

  // Merge default config with user config.
  $config: map.merge($default-config, $config);

  @include customize-focus-indicators($config, 'mat-mdc');
}

@mixin strong-focus-indicators-color($theme-or-color) {
  @if meta.type-of($theme-or-color) == 'color' {
    @include customize-focus-indicators((
        border-color: $theme-or-color
    ), 'mat');
  }
  @else {
    $border-color: inspection.get-theme-color($theme-or-color, primary);
    @include customize-focus-indicators((
        border-color: $border-color
    ), 'mat');
  }
}

@mixin strong-focus-indicators-theme($theme-or-color) {
  @if meta.type-of($theme-or-color) == 'color' {
    @include customize-focus-indicators((
        border-color: $theme-or-color
    ), 'mat');
  }
  @else {
    @include theming.private-check-duplicate-theme-styles($theme-or-color, 'mat-focus-indicators') {
      @if inspection.theme-has($theme-or-color, color) {
        @include strong-focus-indicators-color($theme-or-color);
      }
    }
  }
}

@mixin mdc-strong-focus-indicators-color($theme-or-color) {
  @if meta.type-of($theme-or-color) == 'color' {
    @include customize-focus-indicators((
        border-color: $theme-or-color
    ), 'mat-mdc');
  }
  @else {
    $border-color: inspection.get-theme-color($theme-or-color, primary);
    @include customize-focus-indicators((
        border-color: $border-color
    ), 'mat-mdc');
  }
}

@mixin mdc-strong-focus-indicators-theme($theme-or-color) {
  @if meta.type-of($theme-or-color) == 'color' {
    @include customize-focus-indicators((
        border-color: $theme-or-color
    ), 'mat-mdc');
  }
  @else {
    @include theming.private-check-duplicate-theme-styles(
        $theme-or-color, 'mat-mdc-focus-indicators') {
      @if inspection.theme-has($theme-or-color, color) {
        @include mdc-strong-focus-indicators-color($theme-or-color);
      }
    }
  }
}