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wp-includes/class-wp-theme-json.php

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<?php
/**
 * WP_Theme_JSON class
 *
 * @package WordPress
 * @subpackage Theme
 * @since 5.8.0
 */

/**
 * Class that encapsulates the processing of structures that adhere to the theme.json spec.
 *
 * This class is for internal core usage and is not supposed to be used by extenders (plugins and/or themes).
 * This is a low-level API that may need to do breaking changes. Please,
 * use get_global_settings, get_global_styles, and get_global_stylesheet instead.
 *
 * @access private
 */
#[AllowDynamicProperties]
class WP_Theme_JSON {

    /**
     * Container of data in theme.json format.
     *
     * @since 5.8.0
     * @var array
     */
    protected $theme_json = null;

    /**
     * Holds block metadata extracted from block.json
     * to be shared among all instances so we don't
     * process it twice.
     *
     * @since 5.8.0
     * @since 6.1.0 Initialize as an empty array.
     * @var array
     */
    protected static $blocks_metadata = array();

    /**
     * The CSS selector for the top-level preset settings.
     *
     * @since 6.6.0
     * @var string
     */
    const ROOT_CSS_PROPERTIES_SELECTOR = ':root';

    /**
     * The CSS selector for the top-level styles.
     *
     * @since 5.8.0
     * @var string
     */
    const ROOT_BLOCK_SELECTOR = 'body';

    /**
     * The sources of data this object can represent.
     *
     * @since 5.8.0
     * @since 6.1.0 Added 'blocks'.
     * @var string[]
     */
    const VALID_ORIGINS = array(
        'default',
        'blocks',
        'theme',
        'custom',
    );

    /**
     * Presets are a set of values that serve
     * to bootstrap some styles: colors, font sizes, etc.
     *
     * They are a unkeyed array of values such as:
     *
     *     array(
     *       array(
     *         'slug'      => 'unique-name-within-the-set',
     *         'name'      => 'Name for the UI',
     *         <value_key> => 'value'
     *       ),
     *     )
     *
     * This contains the necessary metadata to process them:
     *
     * - path             => Where to find the preset within the settings section.
     * - prevent_override => Disables override of default presets by theme presets.
     *                       The relationship between whether to override the defaults
     *                       and whether the defaults are enabled is inverse:
     *                         - If defaults are enabled  => theme presets should not be overridden
     *                         - If defaults are disabled => theme presets should be overridden
     *                       For example, a theme sets defaultPalette to false,
     *                       making the default palette hidden from the user.
     *                       In that case, we want all the theme presets to be present,
     *                       so they should override the defaults by setting this false.
     * - use_default_names => whether to use the default names
     * - value_key        => the key that represents the value
     * - value_func       => optionally, instead of value_key, a function to generate
     *                       the value that takes a preset as an argument
     *                       (either value_key or value_func should be present)
     * - css_vars         => template string to use in generating the CSS Custom Property.
     *                       Example output: "--wp--preset--duotone--blue: <value>" will generate as many CSS Custom Properties as presets defined
     *                       substituting the $slug for the slug's value for each preset value.
     * - classes          => array containing a structure with the classes to
     *                       generate for the presets, where for each array item
     *                       the key is the class name and the value the property name.
     *                       The "$slug" substring will be replaced by the slug of each preset.
     *                       For example:
     *                       'classes' => array(
     *                         '.has-$slug-color'            => 'color',
     *                         '.has-$slug-background-color' => 'background-color',
     *                         '.has-$slug-border-color'     => 'border-color',
     *                       )
     * - properties       => array of CSS properties to be used by kses to
     *                       validate the content of each preset
     *                       by means of the remove_insecure_properties method.
     *
     * @since 5.8.0
     * @since 5.9.0 Added the `color.duotone` and `typography.fontFamilies` presets,
     *              `use_default_names` preset key, and simplified the metadata structure.
     * @since 6.0.0 Replaced `override` with `prevent_override` and updated the
     *              `prevent_override` value for `color.duotone` to use `color.defaultDuotone`.
     * @since 6.2.0 Added 'shadow' presets.
     * @since 6.3.0 Replaced value_func for duotone with `null`. Custom properties are handled by class-wp-duotone.php.
     * @var array
     */
    const PRESETS_METADATA = array(
        array(
            'path'              => array( 'color', 'palette' ),
            'prevent_override'  => array( 'color', 'defaultPalette' ),
            'use_default_names' => false,
            'value_key'         => 'color',
            'css_vars'          => '--wp--preset--color--$slug',
            'classes'           => array(
                '.has-$slug-color'            => 'color',
                '.has-$slug-background-color' => 'background-color',
                '.has-$slug-border-color'     => 'border-color',
            ),
            'properties'        => array( 'color', 'background-color', 'border-color' ),
        ),
        array(
            'path'              => array( 'color', 'gradients' ),
            'prevent_override'  => array( 'color', 'defaultGradients' ),
            'use_default_names' => false,
            'value_key'         => 'gradient',
            'css_vars'          => '--wp--preset--gradient--$slug',
            'classes'           => array( '.has-$slug-gradient-background' => 'background' ),
            'properties'        => array( 'background' ),
        ),
        array(
            'path'              => array( 'color', 'duotone' ),
            'prevent_override'  => array( 'color', 'defaultDuotone' ),
            'use_default_names' => false,
            'value_func'        => null, // CSS Custom Properties for duotone are handled by block supports in class-wp-duotone.php.
            'css_vars'          => null,
            'classes'           => array(),
            'properties'        => array( 'filter' ),
        ),
        array(
            'path'              => array( 'typography', 'fontSizes' ),
            'prevent_override'  => false,
            'use_default_names' => true,
            'value_func'        => 'wp_get_typography_font_size_value',
            'css_vars'          => '--wp--preset--font-size--$slug',
            'classes'           => array( '.has-$slug-font-size' => 'font-size' ),
            'properties'        => array( 'font-size' ),
        ),
        array(
            'path'              => array( 'typography', 'fontFamilies' ),
            'prevent_override'  => false,
            'use_default_names' => false,
            'value_key'         => 'fontFamily',
            'css_vars'          => '--wp--preset--font-family--$slug',
            'classes'           => array( '.has-$slug-font-family' => 'font-family' ),
            'properties'        => array( 'font-family' ),
        ),
        array(
            'path'              => array( 'spacing', 'spacingSizes' ),
            'prevent_override'  => false,
            'use_default_names' => true,
            'value_key'         => 'size',
            'css_vars'          => '--wp--preset--spacing--$slug',
            'classes'           => array(),
            'properties'        => array( 'padding', 'margin' ),
        ),
        array(
            'path'              => array( 'shadow', 'presets' ),
            'prevent_override'  => array( 'shadow', 'defaultPresets' ),
            'use_default_names' => false,
            'value_key'         => 'shadow',
            'css_vars'          => '--wp--preset--shadow--$slug',
            'classes'           => array(),
            'properties'        => array( 'box-shadow' ),
        ),
    );

    /**
     * Metadata for style properties.
     *
     * Each element is a direct mapping from the CSS property name to the
     * path to the value in theme.json & block attributes.
     *
     * @since 5.8.0
     * @since 5.9.0 Added the `border-*`, `font-family`, `font-style`, `font-weight`,
     *              `letter-spacing`, `margin-*`, `padding-*`, `--wp--style--block-gap`,
     *              `text-decoration`, `text-transform`, and `filter` properties,
     *              simplified the metadata structure.
     * @since 6.1.0 Added the `border-*-color`, `border-*-width`, `border-*-style`,
     *              `--wp--style--root--padding-*`, and `box-shadow` properties,
     *              removed the `--wp--style--block-gap` property.
     * @since 6.2.0 Added `outline-*`, and `min-height` properties.
     * @since 6.3.0 Added `column-count` property.
     * @since 6.4.0 Added `writing-mode` property.
     * @since 6.5.0 Added `aspect-ratio` property.
     * @since 6.6.0 Added `background-[image|position|repeat|size]` properties.
     *
     * @var array
     */
    const PROPERTIES_METADATA = array(
        'aspect-ratio'                      => array( 'dimensions', 'aspectRatio' ),
        'background'                        => array( 'color', 'gradient' ),
        'background-color'                  => array( 'color', 'background' ),
        'background-image'                  => array( 'background', 'backgroundImage' ),
        'background-position'               => array( 'background', 'backgroundPosition' ),
        'background-repeat'                 => array( 'background', 'backgroundRepeat' ),
        'background-size'                   => array( 'background', 'backgroundSize' ),
        'border-radius'                     => array( 'border', 'radius' ),
        'border-top-left-radius'            => array( 'border', 'radius', 'topLeft' ),
        'border-top-right-radius'           => array( 'border', 'radius', 'topRight' ),
        'border-bottom-left-radius'         => array( 'border', 'radius', 'bottomLeft' ),
        'border-bottom-right-radius'        => array( 'border', 'radius', 'bottomRight' ),
        'border-color'                      => array( 'border', 'color' ),
        'border-width'                      => array( 'border', 'width' ),
        'border-style'                      => array( 'border', 'style' ),
        'border-top-color'                  => array( 'border', 'top', 'color' ),
        'border-top-width'                  => array( 'border', 'top', 'width' ),
        'border-top-style'                  => array( 'border', 'top', 'style' ),
        'border-right-color'                => array( 'border', 'right', 'color' ),
        'border-right-width'                => array( 'border', 'right', 'width' ),
        'border-right-style'                => array( 'border', 'right', 'style' ),
        'border-bottom-color'               => array( 'border', 'bottom', 'color' ),
        'border-bottom-width'               => array( 'border', 'bottom', 'width' ),
        'border-bottom-style'               => array( 'border', 'bottom', 'style' ),
        'border-left-color'                 => array( 'border', 'left', 'color' ),
        'border-left-width'                 => array( 'border', 'left', 'width' ),
        'border-left-style'                 => array( 'border', 'left', 'style' ),
        'color'                             => array( 'color', 'text' ),
        'column-count'                      => array( 'typography', 'textColumns' ),
        'font-family'                       => array( 'typography', 'fontFamily' ),
        'font-size'                         => array( 'typography', 'fontSize' ),
        'font-style'                        => array( 'typography', 'fontStyle' ),
        'font-weight'                       => array( 'typography', 'fontWeight' ),
        'letter-spacing'                    => array( 'typography', 'letterSpacing' ),
        'line-height'                       => array( 'typography', 'lineHeight' ),
        'margin'                            => array( 'spacing', 'margin' ),
        'margin-top'                        => array( 'spacing', 'margin', 'top' ),
        'margin-right'                      => array( 'spacing', 'margin', 'right' ),
        'margin-bottom'                     => array( 'spacing', 'margin', 'bottom' ),
        'margin-left'                       => array( 'spacing', 'margin', 'left' ),
        'min-height'                        => array( 'dimensions', 'minHeight' ),
        'outline-color'                     => array( 'outline', 'color' ),
        'outline-offset'                    => array( 'outline', 'offset' ),
        'outline-style'                     => array( 'outline', 'style' ),
        'outline-width'                     => array( 'outline', 'width' ),
        'padding'                           => array( 'spacing', 'padding' ),
        'padding-top'                       => array( 'spacing', 'padding', 'top' ),
        'padding-right'                     => array( 'spacing', 'padding', 'right' ),
        'padding-bottom'                    => array( 'spacing', 'padding', 'bottom' ),
        'padding-left'                      => array( 'spacing', 'padding', 'left' ),
        '--wp--style--root--padding'        => array( 'spacing', 'padding' ),
        '--wp--style--root--padding-top'    => array( 'spacing', 'padding', 'top' ),
        '--wp--style--root--padding-right'  => array( 'spacing', 'padding', 'right' ),
        '--wp--style--root--padding-bottom' => array( 'spacing', 'padding', 'bottom' ),
        '--wp--style--root--padding-left'   => array( 'spacing', 'padding', 'left' ),
        'text-decoration'                   => array( 'typography', 'textDecoration' ),
        'text-transform'                    => array( 'typography', 'textTransform' ),
        'filter'                            => array( 'filter', 'duotone' ),
        'box-shadow'                        => array( 'shadow' ),
        'writing-mode'                      => array( 'typography', 'writingMode' ),
    );

    /**
     * Indirect metadata for style properties that are not directly output.
     *
     * Each element maps from a CSS property name to an array of
     * paths to the value in theme.json & block attributes.
     *
     * Indirect properties are not output directly by `compute_style_properties`,
     * but are used elsewhere in the processing of global styles. The indirect
     * property is used to validate whether a style value is allowed.
     *
     * @since 6.2.0
     * @since 6.6.0 Added background-image properties.
     *
     * @var array
     */
    const INDIRECT_PROPERTIES_METADATA = array(
        'gap'        => array(
            array( 'spacing', 'blockGap' ),
        ),
        'column-gap' => array(
            array( 'spacing', 'blockGap', 'left' ),
        ),
        'row-gap'    => array(
            array( 'spacing', 'blockGap', 'top' ),
        ),
        'max-width'  => array(
            array( 'layout', 'contentSize' ),
            array( 'layout', 'wideSize' ),
        ),
        'background-image' => array(
            array( 'background', 'backgroundImage', 'url' ),
        ),
    );

    /**
     * Protected style properties.
     *
     * These style properties are only rendered if a setting enables it
     * via a value other than `null`.
     *
     * Each element maps the style property to the corresponding theme.json
     * setting key.
     *
     * @since 5.9.0
     */
    const PROTECTED_PROPERTIES = array(
        'spacing.blockGap' => array( 'spacing', 'blockGap' ),
    );

    /**
     * The top-level keys a theme.json can have.
     *
     * @since 5.8.0 As `ALLOWED_TOP_LEVEL_KEYS`.
     * @since 5.9.0 Renamed from `ALLOWED_TOP_LEVEL_KEYS` to `VALID_TOP_LEVEL_KEYS`,
     *              added the `customTemplates` and `templateParts` values.
     * @since 6.3.0 Added the `description` value.
     * @var string[]
     */
    const VALID_TOP_LEVEL_KEYS = array(
        'customTemplates',
        'description',
        'patterns',
        'settings',
        'styles',
        'templateParts',
        'title',
        'version',
    );

    /**
     * The valid properties under the settings key.
     *
     * @since 5.8.0 As `ALLOWED_SETTINGS`.
     * @since 5.9.0 Renamed from `ALLOWED_SETTINGS` to `VALID_SETTINGS`,
     *              added new properties for `border`, `color`, `spacing`,
     *              and `typography`, and renamed others according to the new schema.
     * @since 6.0.0 Added `color.defaultDuotone`.
     * @since 6.1.0 Added `layout.definitions` and `useRootPaddingAwareAlignments`.
     * @since 6.2.0 Added `dimensions.minHeight`, 'shadow.presets', 'shadow.defaultPresets',
     *              `position.fixed` and `position.sticky`.
     * @since 6.3.0 Added support for `typography.textColumns`, removed `layout.definitions`.
     * @since 6.4.0 Added support for `layout.allowEditing`, `background.backgroundImage`,
     *              `typography.writingMode`, `lightbox.enabled` and `lightbox.allowEditing`.
     * @since 6.5.0 Added support for `layout.allowCustomContentAndWideSize`,
     *              `background.backgroundSize` and `dimensions.aspectRatio`.
     * @var array
     */
    const VALID_SETTINGS = array(
        'appearanceTools'               => null,
        'useRootPaddingAwareAlignments' => null,
        'background'                    => array(
            'backgroundImage' => null,
            'backgroundSize'  => null,
        ),
        'border'                        => array(
            'color'  => null,
            'radius' => null,
            'style'  => null,
            'width'  => null,
        ),
        'color'                         => array(
            'background'       => null,
            'custom'           => null,
            'customDuotone'    => null,
            'customGradient'   => null,
            'defaultDuotone'   => null,
            'defaultGradients' => null,
            'defaultPalette'   => null,
            'duotone'          => null,
            'gradients'        => null,
            'link'             => null,
            'heading'          => null,
            'button'           => null,
            'caption'          => null,
            'palette'          => null,
            'text'             => null,
        ),
        'custom'                        => null,
        'dimensions'                    => array(
            'aspectRatio' => null,
            'minHeight'   => null,
        ),
        'layout'                        => array(
            'contentSize'                   => null,
            'wideSize'                      => null,
            'allowEditing'                  => null,
            'allowCustomContentAndWideSize' => null,
        ),
        'lightbox'                      => array(
            'enabled'      => null,
            'allowEditing' => null,
        ),
        'position'                      => array(
            'fixed'  => null,
            'sticky' => null,
        ),
        'spacing'                       => array(
            'customSpacingSize' => null,
            'spacingSizes'      => null,
            'spacingScale'      => null,
            'blockGap'          => null,
            'margin'            => null,
            'padding'           => null,
            'units'             => null,
        ),
        'shadow'                        => array(
            'presets'        => null,
            'defaultPresets' => null,
        ),
        'typography'                    => array(
            'fluid'          => null,
            'customFontSize' => null,
            'dropCap'        => null,
            'fontFamilies'   => null,
            'fontSizes'      => null,
            'fontStyle'      => null,
            'fontWeight'     => null,
            'letterSpacing'  => null,
            'lineHeight'     => null,
            'textColumns'    => null,
            'textDecoration' => null,
            'textTransform'  => null,
            'writingMode'    => null,
        ),
    );

    /*
     * The valid properties for fontFamilies under settings key.
     *
     * @since 6.5.0
     *
     * @var array
     */
    const FONT_FAMILY_SCHEMA = array(
        array(
            'fontFamily' => null,
            'name'       => null,
            'slug'       => null,
            'fontFace'   => array(
                array(
                    'ascentOverride'        => null,
                    'descentOverride'       => null,
                    'fontDisplay'           => null,
                    'fontFamily'            => null,
                    'fontFeatureSettings'   => null,
                    'fontStyle'             => null,
                    'fontStretch'           => null,
                    'fontVariationSettings' => null,
                    'fontWeight'            => null,
                    'lineGapOverride'       => null,
                    'sizeAdjust'            => null,
                    'src'                   => null,
                    'unicodeRange'          => null,
                ),
            ),
        ),
    );

    /**
     * The valid properties under the styles key.
     *
     * @since 5.8.0 As `ALLOWED_STYLES`.
     * @since 5.9.0 Renamed from `ALLOWED_STYLES` to `VALID_STYLES`,
     *              added new properties for `border`, `filter`, `spacing`,
     *              and `typography`.
     * @since 6.1.0 Added new side properties for `border`,
     *              added new property `shadow`,
     *              updated `blockGap` to be allowed at any level.
     * @since 6.2.0 Added `outline`, and `minHeight` properties.
     * @since 6.3.0 Added support for `typography.textColumns`.
     * @since 6.5.0 Added support for `dimensions.aspectRatio`.
     * @since 6.6.0 Added `background` sub properties to top-level only.
     *
     * @var array
     */
    const VALID_STYLES = array(
        'background' => array(
            'backgroundImage'    => 'top',
            'backgroundPosition' => 'top',
            'backgroundRepeat'   => 'top',
            'backgroundSize'     => 'top',
        ),
        'border'     => array(
            'color'  => null,
            'radius' => null,
            'style'  => null,
            'width'  => null,
            'top'    => null,
            'right'  => null,
            'bottom' => null,
            'left'   => null,
        ),
        'color'      => array(
            'background' => null,
            'gradient'   => null,
            'text'       => null,
        ),
        'dimensions' => array(
            'aspectRatio' => null,
            'minHeight'   => null,
        ),
        'filter'     => array(
            'duotone' => null,
        ),
        'outline'    => array(
            'color'  => null,
            'offset' => null,
            'style'  => null,
            'width'  => null,
        ),
        'shadow'     => null,
        'spacing'    => array(
            'margin'   => null,
            'padding'  => null,
            'blockGap' => null,
        ),
        'typography' => array(
            'fontFamily'     => null,
            'fontSize'       => null,
            'fontStyle'      => null,
            'fontWeight'     => null,
            'letterSpacing'  => null,
            'lineHeight'     => null,
            'textColumns'    => null,
            'textDecoration' => null,
            'textTransform'  => null,
            'writingMode'    => null,
        ),
        'css'        => null,
    );

    /**
     * Defines which pseudo selectors are enabled for which elements.
     *
     * The order of the selectors should be: link, any-link, visited, hover, focus, active.
     * This is to ensure the user action (hover, focus and active) styles have a higher
     * specificity than the visited styles, which in turn have a higher specificity than
     * the unvisited styles.
     *
     * See https://core.trac.wordpress.org/ticket/56928.
     * Note: this will affect both top-level and block-level elements.
     *
     * @since 6.1.0
     * @since 6.2.0 Added support for ':link' and ':any-link'.
     */
    const VALID_ELEMENT_PSEUDO_SELECTORS = array(
        'link'   => array( ':link', ':any-link', ':visited', ':hover', ':focus', ':active' ),
        'button' => array( ':link', ':any-link', ':visited', ':hover', ':focus', ':active' ),
    );

    /**
     * The valid elements that can be found under styles.
     *
     * @since 5.8.0
     * @since 6.1.0 Added `heading`, `button`, and `caption` elements.
     * @var string[]
     */
    const ELEMENTS = array(
        'link'    => 'a:where(:not(.wp-element-button))', // The `where` is needed to lower the specificity.
        'heading' => 'h1, h2, h3, h4, h5, h6',
        'h1'      => 'h1',
        'h2'      => 'h2',
        'h3'      => 'h3',
        'h4'      => 'h4',
        'h5'      => 'h5',
        'h6'      => 'h6',
        // We have the .wp-block-button__link class so that this will target older buttons that have been serialized.
        'button'  => '.wp-element-button, .wp-block-button__link',
        // The block classes are necessary to target older content that won't use the new class names.
        'caption' => '.wp-element-caption, .wp-block-audio figcaption, .wp-block-embed figcaption, .wp-block-gallery figcaption, .wp-block-image figcaption, .wp-block-table figcaption, .wp-block-video figcaption',
        'cite'    => 'cite',
    );

    const __EXPERIMENTAL_ELEMENT_CLASS_NAMES = array(
        'button'  => 'wp-element-button',
        'caption' => 'wp-element-caption',
    );

    /**
     * List of block support features that can have their related styles
     * generated under their own feature level selector rather than the block's.
     *
     * @since 6.1.0
     * @var string[]
     */
    const BLOCK_SUPPORT_FEATURE_LEVEL_SELECTORS = array(
        '__experimentalBorder' => 'border',
        'color'                => 'color',
        'spacing'              => 'spacing',
        'typography'           => 'typography',
    );

    /**
     * Return the input schema at the root and per origin.
     *
     * @since 6.5.0
     *
     * @param array $schema The base schema.
     * @return array The schema at the root and per origin.
     *
     * Example:
     * schema_in_root_and_per_origin(
     *   array(
     *    'fontFamily' => null,
     *    'slug' => null,
     *   )
     * )
     *
     * Returns:
     * array(
     *  'fontFamily' => null,
     *  'slug' => null,
     *  'default' => array(
     *    'fontFamily' => null,
     *    'slug' => null,
     *  ),
     *  'blocks' => array(
     *    'fontFamily' => null,
     *    'slug' => null,
     *  ),
     *  'theme' => array(
     *     'fontFamily' => null,
     *     'slug' => null,
     *  ),
     *  'custom' => array(
     *     'fontFamily' => null,
     *     'slug' => null,
     *  ),
     * )
     */
    protected static function schema_in_root_and_per_origin( $schema ) {
        $schema_in_root_and_per_origin = $schema;
        foreach ( static::VALID_ORIGINS as $origin ) {
            $schema_in_root_and_per_origin[ $origin ] = $schema;
        }
        return $schema_in_root_and_per_origin;
    }

    /**
     * Returns a class name by an element name.
     *
     * @since 6.1.0
     *
     * @param string $element The name of the element.
     * @return string The name of the class.
     */
    public static function get_element_class_name( $element ) {
        $class_name = '';

        if ( isset( static::__EXPERIMENTAL_ELEMENT_CLASS_NAMES[ $element ] ) ) {
            $class_name = static::__EXPERIMENTAL_ELEMENT_CLASS_NAMES[ $element ];
        }

        return $class_name;
    }

    /**
     * Options that settings.appearanceTools enables.
     *
     * @since 6.0.0
     * @since 6.2.0 Added `dimensions.minHeight` and `position.sticky`.
     * @since 6.4.0 Added `background.backgroundImage`.
     * @since 6.5.0 Added `background.backgroundSize` and `dimensions.aspectRatio`.
     * @var array
     */
    const APPEARANCE_TOOLS_OPT_INS = array(
        array( 'background', 'backgroundImage' ),
        array( 'background', 'backgroundSize' ),
        array( 'border', 'color' ),
        array( 'border', 'radius' ),
        array( 'border', 'style' ),
        array( 'border', 'width' ),
        array( 'color', 'link' ),
        array( 'color', 'heading' ),
        array( 'color', 'button' ),
        array( 'color', 'caption' ),
        array( 'dimensions', 'aspectRatio' ),
        array( 'dimensions', 'minHeight' ),
        array( 'position', 'sticky' ),
        array( 'spacing', 'blockGap' ),
        array( 'spacing', 'margin' ),
        array( 'spacing', 'padding' ),
        array( 'typography', 'lineHeight' ),
    );

    /**
     * The latest version of the schema in use.
     *
     * @since 5.8.0
     * @since 5.9.0 Changed value from 1 to 2.
     * @var int
     */
    const LATEST_SCHEMA = 2;

    /**
     * Constructor.
     *
     * @since 5.8.0
     *
     * @param array  $theme_json A structure that follows the theme.json schema.
     * @param string $origin     Optional. What source of data this object represents.
     *                           One of 'default', 'theme', or 'custom'. Default 'theme'.
     */
    public function __construct( $theme_json = array(), $origin = 'theme' ) {
        if ( ! in_array( $origin, static::VALID_ORIGINS, true ) ) {
            $origin = 'theme';
        }

        $this->theme_json    = WP_Theme_JSON_Schema::migrate( $theme_json );
        $valid_block_names   = array_keys( static::get_blocks_metadata() );
        $valid_element_names = array_keys( static::ELEMENTS );
        $valid_variations    = static::get_valid_block_style_variations();
        $theme_json          = static::sanitize( $this->theme_json, $valid_block_names, $valid_element_names, $valid_variations );
        $this->theme_json    = static::maybe_opt_in_into_settings( $theme_json );

        // Internally, presets are keyed by origin.
        $nodes = static::get_setting_nodes( $this->theme_json );
        foreach ( $nodes as $node ) {
            foreach ( static::PRESETS_METADATA as $preset_metadata ) {
                $path = $node['path'];
                foreach ( $preset_metadata['path'] as $subpath ) {
                    $path[] = $subpath;
                }
                $preset = _wp_array_get( $this->theme_json, $path, null );
                if ( null !== $preset ) {
                    // If the preset is not already keyed by origin.
                    if ( isset( $preset[0] ) || empty( $preset ) ) {
                        _wp_array_set( $this->theme_json, $path, array( $origin => $preset ) );
                    }
                }
            }
        }
    }

    /**
     * Enables some opt-in settings if theme declared support.
     *
     * @since 5.9.0
     *
     * @param array $theme_json A theme.json structure to modify.
     * @return array The modified theme.json structure.
     */
    protected static function maybe_opt_in_into_settings( $theme_json ) {
        $new_theme_json = $theme_json;

        if (
            isset( $new_theme_json['settings']['appearanceTools'] ) &&
            true === $new_theme_json['settings']['appearanceTools']
        ) {
            static::do_opt_in_into_settings( $new_theme_json['settings'] );
        }

        if ( isset( $new_theme_json['settings']['blocks'] ) && is_array( $new_theme_json['settings']['blocks'] ) ) {
            foreach ( $new_theme_json['settings']['blocks'] as &$block ) {
                if ( isset( $block['appearanceTools'] ) && ( true === $block['appearanceTools'] ) ) {
                    static::do_opt_in_into_settings( $block );
                }
            }
        }

        return $new_theme_json;
    }

    /**
     * Enables some settings.
     *
     * @since 5.9.0
     *
     * @param array $context The context to which the settings belong.
     */
    protected static function do_opt_in_into_settings( &$context ) {
        foreach ( static::APPEARANCE_TOOLS_OPT_INS as $path ) {
            /*
             * Use "unset prop" as a marker instead of "null" because
             * "null" can be a valid value for some props (e.g. blockGap).
             */
            if ( 'unset prop' === _wp_array_get( $context, $path, 'unset prop' ) ) {
                _wp_array_set( $context, $path, true );
            }
        }

        unset( $context['appearanceTools'] );
    }

    /**
     * Sanitizes the input according to the schemas.
     *
     * @since 5.8.0
     * @since 5.9.0 Added the `$valid_block_names` and `$valid_element_name` parameters.
     * @since 6.3.0 Added the `$valid_variations` parameter.
     *
     * @param array $input               Structure to sanitize.
     * @param array $valid_block_names   List of valid block names.
     * @param array $valid_element_names List of valid element names.
     * @param array $valid_variations    List of valid variations per block.
     * @return array The sanitized output.
     */
    protected static function sanitize( $input, $valid_block_names, $valid_element_names, $valid_variations ) {

        $output = array();

        if ( ! is_array( $input ) ) {
            return $output;
        }

        // Preserve only the top most level keys.
        $output = array_intersect_key( $input, array_flip( static::VALID_TOP_LEVEL_KEYS ) );

        /*
         * Remove any rules that are annotated as "top" in VALID_STYLES constant.
         * Some styles are only meant to be available at the top-level (e.g.: blockGap),
         * hence, the schema for blocks & elements should not have them.
         */
        $styles_non_top_level = static::VALID_STYLES;
        foreach ( array_keys( $styles_non_top_level ) as $section ) {
            // array_key_exists() needs to be used instead of isset() because the value can be null.
            if ( array_key_exists( $section, $styles_non_top_level ) && is_array( $styles_non_top_level[ $section ] ) ) {
                foreach ( array_keys( $styles_non_top_level[ $section ] ) as $prop ) {
                    if ( 'top' === $styles_non_top_level[ $section ][ $prop ] ) {
                        unset( $styles_non_top_level[ $section ][ $prop ] );
                    }
                }
            }
        }

        // Build the schema based on valid block & element names.
        $schema                 = array();
        $schema_styles_elements = array();

        /*
         * Set allowed element pseudo selectors based on per element allow list.
         * Target data structure in schema:
         * e.g.
         * - top level elements: `$schema['styles']['elements']['link'][':hover']`.
         * - block level elements: `$schema['styles']['blocks']['core/button']['elements']['link'][':hover']`.
         */
        foreach ( $valid_element_names as $element ) {
            $schema_styles_elements[ $element ] = $styles_non_top_level;

            if ( isset( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $element ] ) ) {
                foreach ( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $element ] as $pseudo_selector ) {
                    $schema_styles_elements[ $element ][ $pseudo_selector ] = $styles_non_top_level;
                }
            }
        }

        $schema_styles_blocks   = array();
        $schema_settings_blocks = array();
        foreach ( $valid_block_names as $block ) {
            // Build the schema for each block style variation.
            $style_variation_names = array();
            if (
                ! empty( $input['styles']['blocks'][ $block ]['variations'] ) &&
                is_array( $input['styles']['blocks'][ $block ]['variations'] ) &&
                isset( $valid_variations[ $block ] )
            ) {
                $style_variation_names = array_intersect(
                    array_keys( $input['styles']['blocks'][ $block ]['variations'] ),
                    $valid_variations[ $block ]
                );
            }

            $schema_styles_variations = array();
            if ( ! empty( $style_variation_names ) ) {
                $schema_styles_variations = array_fill_keys( $style_variation_names, $styles_non_top_level );
            }

            $schema_settings_blocks[ $block ]             = static::VALID_SETTINGS;
            $schema_styles_blocks[ $block ]               = $styles_non_top_level;
            $schema_styles_blocks[ $block ]['elements']   = $schema_styles_elements;
            $schema_styles_blocks[ $block ]['variations'] = $schema_styles_variations;
        }

        $schema['styles']                                 = static::VALID_STYLES;
        $schema['styles']['blocks']                       = $schema_styles_blocks;
        $schema['styles']['elements']                     = $schema_styles_elements;
        $schema['settings']                               = static::VALID_SETTINGS;
        $schema['settings']['blocks']                     = $schema_settings_blocks;
        $schema['settings']['typography']['fontFamilies'] = static::schema_in_root_and_per_origin( static::FONT_FAMILY_SCHEMA );

        // Remove anything that's not present in the schema.
        foreach ( array( 'styles', 'settings' ) as $subtree ) {
            if ( ! isset( $input[ $subtree ] ) ) {
                continue;
            }

            if ( ! is_array( $input[ $subtree ] ) ) {
                unset( $output[ $subtree ] );
                continue;
            }

            $result = static::remove_keys_not_in_schema( $input[ $subtree ], $schema[ $subtree ] );

            if ( empty( $result ) ) {
                unset( $output[ $subtree ] );
            } else {
                $output[ $subtree ] = static::resolve_custom_css_format( $result );
            }
        }

        return $output;
    }

    /**
     * Appends a sub-selector to an existing one.
     *
     * Given the compounded $selector "h1, h2, h3"
     * and the $to_append selector ".some-class" the result will be
     * "h1.some-class, h2.some-class, h3.some-class".
     *
     * @since 5.8.0
     * @since 6.1.0 Added append position.
     * @since 6.3.0 Removed append position parameter.
     *
     * @param string $selector  Original selector.
     * @param string $to_append Selector to append.
     * @return string The new selector.
     */
    protected static function append_to_selector( $selector, $to_append ) {
        if ( ! str_contains( $selector, ',' ) ) {
            return $selector . $to_append;
        }
        $new_selectors = array();
        $selectors     = explode( ',', $selector );
        foreach ( $selectors as $sel ) {
            $new_selectors[] = $sel . $to_append;
        }
        return implode( ',', $new_selectors );
    }

    /**
     * Prepends a sub-selector to an existing one.
     *
     * Given the compounded $selector "h1, h2, h3"
     * and the $to_prepend selector ".some-class " the result will be
     * ".some-class h1, .some-class  h2, .some-class  h3".
     *
     * @since 6.3.0
     *
     * @param string $selector   Original selector.
     * @param string $to_prepend Selector to prepend.
     * @return string The new selector.
     */
    protected static function prepend_to_selector( $selector, $to_prepend ) {
        if ( ! str_contains( $selector, ',' ) ) {
            return $to_prepend . $selector;
        }
        $new_selectors = array();
        $selectors     = explode( ',', $selector );
        foreach ( $selectors as $sel ) {
            $new_selectors[] = $to_prepend . $sel;
        }
        return implode( ',', $new_selectors );
    }

    /**
     * Returns the metadata for each block.
     *
     * Example:
     *
     *     {
     *       'core/paragraph': {
     *         'selector': 'p',
     *         'elements': {
     *           'link' => 'link selector',
     *           'etc'  => 'element selector'
     *         }
     *       },
     *       'core/heading': {
     *         'selector': 'h1',
     *         'elements': {}
     *       },
     *       'core/image': {
     *         'selector': '.wp-block-image',
     *         'duotone': 'img',
     *         'elements': {}
     *       }
     *     }
     *
     * @since 5.8.0
     * @since 5.9.0 Added `duotone` key with CSS selector.
     * @since 6.1.0 Added `features` key with block support feature level selectors.
     * @since 6.3.0 Refactored and stabilized selectors API.
     *
     * @return array Block metadata.
     */
    protected static function get_blocks_metadata() {
        $registry = WP_Block_Type_Registry::get_instance();
        $blocks   = $registry->get_all_registered();

        // Is there metadata for all currently registered blocks?
        $blocks = array_diff_key( $blocks, static::$blocks_metadata );
        if ( empty( $blocks ) ) {
            return static::$blocks_metadata;
        }

        foreach ( $blocks as $block_name => $block_type ) {
            $root_selector = wp_get_block_css_selector( $block_type );

            static::$blocks_metadata[ $block_name ]['selector']  = $root_selector;
            static::$blocks_metadata[ $block_name ]['selectors'] = static::get_block_selectors( $block_type, $root_selector );

            $elements = static::get_block_element_selectors( $root_selector );
            if ( ! empty( $elements ) ) {
                static::$blocks_metadata[ $block_name ]['elements'] = $elements;
            }

            // The block may or may not have a duotone selector.
            $duotone_selector = wp_get_block_css_selector( $block_type, 'filter.duotone' );

            // Keep backwards compatibility for support.color.__experimentalDuotone.
            if ( null === $duotone_selector ) {
                $duotone_support = isset( $block_type->supports['color']['__experimentalDuotone'] )
                    ? $block_type->supports['color']['__experimentalDuotone']
                    : null;

                if ( $duotone_support ) {
                    $root_selector    = wp_get_block_css_selector( $block_type );
                    $duotone_selector = static::scope_selector( $root_selector, $duotone_support );
                }
            }

            if ( null !== $duotone_selector ) {
                static::$blocks_metadata[ $block_name ]['duotone'] = $duotone_selector;
            }

            // If the block has style variations, append their selectors to the block metadata.
            if ( ! empty( $block_type->styles ) ) {
                $style_selectors = array();
                foreach ( $block_type->styles as $style ) {
                    $style_selectors[ $style['name'] ] = static::get_block_style_variation_selector( $style['name'], static::$blocks_metadata[ $block_name ]['selector'] );
                }
                static::$blocks_metadata[ $block_name ]['styleVariations'] = $style_selectors;
            }
        }

        return static::$blocks_metadata;
    }

    /**
     * Given a tree, removes the keys that are not present in the schema.
     *
     * It is recursive and modifies the input in-place.
     *
     * @since 5.8.0
     *
     * @param array $tree   Input to process.
     * @param array $schema Schema to adhere to.
     * @return array The modified $tree.
     */
    protected static function remove_keys_not_in_schema( $tree, $schema ) {
        if ( ! is_array( $tree ) ) {
            return $tree;
        }

        foreach ( $tree as $key => $value ) {
            // Remove keys not in the schema or with null/empty values.
            if ( ! array_key_exists( $key, $schema ) ) {
                unset( $tree[ $key ] );
                continue;
            }

            if ( is_array( $schema[ $key ] ) ) {
                if ( ! is_array( $value ) ) {
                    unset( $tree[ $key ] );
                } elseif ( wp_is_numeric_array( $value ) ) {
                    // If indexed, process each item in the array.
                    foreach ( $value as $item_key => $item_value ) {
                        if ( isset( $schema[ $key ][0] ) && is_array( $schema[ $key ][0] ) ) {
                            $tree[ $key ][ $item_key ] = self::remove_keys_not_in_schema( $item_value, $schema[ $key ][0] );
                        } else {
                            // If the schema does not define a further structure, keep the value as is.
                            $tree[ $key ][ $item_key ] = $item_value;
                        }
                    }
                } else {
                    // If associative, process as a single object.
                    $tree[ $key ] = self::remove_keys_not_in_schema( $value, $schema[ $key ] );

                    if ( empty( $tree[ $key ] ) ) {
                        unset( $tree[ $key ] );
                    }
                }
            }
        }
        return $tree;
    }

    /**
     * Returns the existing settings for each block.
     *
     * Example:
     *
     *     {
     *       'root': {
     *         'color': {
     *           'custom': true
     *         }
     *       },
     *       'core/paragraph': {
     *         'spacing': {
     *           'customPadding': true
     *         }
     *       }
     *     }
     *
     * @since 5.8.0
     *
     * @return array Settings per block.
     */
    public function get_settings() {
        if ( ! isset( $this->theme_json['settings'] ) ) {
            return array();
        } else {
            return $this->theme_json['settings'];
        }
    }

    /**
     * Returns the stylesheet that results of processing
     * the theme.json structure this object represents.
     *
     * @since 5.8.0
     * @since 5.9.0 Removed the `$type` parameter, added the `$types` and `$origins` parameters.
     * @since 6.3.0 Add fallback layout styles for Post Template when block gap support isn't available.
     *
     * @param string[] $types   Types of styles to load. Will load all by default. It accepts:
     *                          - `variables`: only the CSS Custom Properties for presets & custom ones.
     *                          - `styles`: only the styles section in theme.json.
     *                          - `presets`: only the classes for the presets.
     * @param string[] $origins A list of origins to include. By default it includes VALID_ORIGINS.
     * @param array    $options An array of options for now used for internal purposes only (may change without notice).
     *                          The options currently supported are 'scope' that makes sure all style are scoped to a
     *                          given selector, and root_selector which overwrites and forces a given selector to be
     *                          used on the root node.
     * @return string The resulting stylesheet.
     */
    public function get_stylesheet( $types = array( 'variables', 'styles', 'presets' ), $origins = null, $options = array() ) {
        if ( null === $origins ) {
            $origins = static::VALID_ORIGINS;
        }

        if ( is_string( $types ) ) {
            // Dispatch error and map old arguments to new ones.
            _deprecated_argument( __FUNCTION__, '5.9.0' );
            if ( 'block_styles' === $types ) {
                $types = array( 'styles', 'presets' );
            } elseif ( 'css_variables' === $types ) {
                $types = array( 'variables' );
            } else {
                $types = array( 'variables', 'styles', 'presets' );
            }
        }

        $blocks_metadata = static::get_blocks_metadata();
        $style_nodes     = static::get_style_nodes( $this->theme_json, $blocks_metadata );
        $setting_nodes   = static::get_setting_nodes( $this->theme_json, $blocks_metadata );

        $root_style_key    = array_search( static::ROOT_BLOCK_SELECTOR, array_column( $style_nodes, 'selector' ), true );
        $root_settings_key = array_search( static::ROOT_BLOCK_SELECTOR, array_column( $setting_nodes, 'selector' ), true );

        if ( ! empty( $options['scope'] ) ) {
            foreach ( $setting_nodes as &$node ) {
                $node['selector'] = static::scope_selector( $options['scope'], $node['selector'] );
            }
            foreach ( $style_nodes as &$node ) {
                $node['selector'] = static::scope_selector( $options['scope'], $node['selector'] );
            }
            unset( $node );
        }

        if ( ! empty( $options['root_selector'] ) ) {
            if ( false !== $root_settings_key ) {
                $setting_nodes[ $root_settings_key ]['selector'] = $options['root_selector'];
            }
            if ( false !== $root_style_key ) {
                $style_nodes[ $root_style_key ]['selector'] = $options['root_selector'];
            }
        }

        $stylesheet = '';

        if ( in_array( 'variables', $types, true ) ) {
            $stylesheet .= $this->get_css_variables( $setting_nodes, $origins );
        }

        if ( in_array( 'styles', $types, true ) ) {
            if ( false !== $root_style_key ) {
                $stylesheet .= $this->get_root_layout_rules( $style_nodes[ $root_style_key ]['selector'], $style_nodes[ $root_style_key ] );
            }
            $stylesheet .= $this->get_block_classes( $style_nodes );
        } elseif ( in_array( 'base-layout-styles', $types, true ) ) {
            $root_selector          = static::ROOT_BLOCK_SELECTOR;
            $columns_selector       = '.wp-block-columns';
            $post_template_selector = '.wp-block-post-template';
            if ( ! empty( $options['scope'] ) ) {
                $root_selector          = static::scope_selector( $options['scope'], $root_selector );
                $columns_selector       = static::scope_selector( $options['scope'], $columns_selector );
                $post_template_selector = static::scope_selector( $options['scope'], $post_template_selector );
            }
            if ( ! empty( $options['root_selector'] ) ) {
                $root_selector = $options['root_selector'];
            }
            /*
             * Base layout styles are provided as part of `styles`, so only output separately if explicitly requested.
             * For backwards compatibility, the Columns block is explicitly included, to support a different default gap value.
             */
            $base_styles_nodes = array(
                array(
                    'path'     => array( 'styles' ),
                    'selector' => $root_selector,
                ),
                array(
                    'path'     => array( 'styles', 'blocks', 'core/columns' ),
                    'selector' => $columns_selector,
                    'name'     => 'core/columns',
                ),
                array(
                    'path'     => array( 'styles', 'blocks', 'core/post-template' ),
                    'selector' => $post_template_selector,
                    'name'     => 'core/post-template',
                ),
            );

            foreach ( $base_styles_nodes as $base_style_node ) {
                $stylesheet .= $this->get_layout_styles( $base_style_node, $types );
            }
        }

        if ( in_array( 'presets', $types, true ) ) {
            $stylesheet .= $this->get_preset_classes( $setting_nodes, $origins );
        }

        return $stylesheet;
    }

    /**
     * Processes the CSS, to apply nesting.
     *
     * @since 6.2.0
     *
     * @param string $css      The CSS to process.
     * @param string $selector The selector to nest.
     * @return string The processed CSS.
     */
    protected function process_blocks_custom_css( $css, $selector ) {
        $processed_css = '';

        // Split CSS nested rules.
        $parts = explode( '&', $css );
        foreach ( $parts as $part ) {
            $is_root_css = ( ! str_contains( $part, '{' ) );
            if ( $is_root_css ) {
                // If the part doesn't contain braces, it applies to the root level.
                $processed_css .= trim( $selector ) . '{' . trim( $part ) . '}';
            } else {
                // If the part contains braces, it's a nested CSS rule.
                $part = explode( '{', str_replace( '}', '', $part ) );
                if ( count( $part ) !== 2 ) {
                    continue;
                }
                $nested_selector = $part[0];
                $css_value       = $part[1];
                $part_selector   = str_starts_with( $nested_selector, ' ' )
                    ? static::scope_selector( $selector, $nested_selector )
                    : static::append_to_selector( $selector, $nested_selector );
                $processed_css  .= $part_selector . '{' . trim( $css_value ) . '}';
            }
        }
        return $processed_css;
    }

    /**
     * Returns the global styles custom CSS.
     *
     * @since 6.2.0
     *
     * @return string The global styles custom CSS.
     */
    public function get_custom_css() {
        // Add the global styles root CSS.
        $stylesheet = isset( $this->theme_json['styles']['css'] ) ? $this->theme_json['styles']['css'] : '';

        // Add the global styles block CSS.
        if ( isset( $this->theme_json['styles']['blocks'] ) ) {
            foreach ( $this->theme_json['styles']['blocks'] as $name => $node ) {
                $custom_block_css = isset( $this->theme_json['styles']['blocks'][ $name ]['css'] )
                    ? $this->theme_json['styles']['blocks'][ $name ]['css']
                    : null;
                if ( $custom_block_css ) {
                    $selector    = static::$blocks_metadata[ $name ]['selector'];
                    $stylesheet .= $this->process_blocks_custom_css( $custom_block_css, $selector );
                }
            }
        }

        return $stylesheet;
    }

    /**
     * Returns the page templates of the active theme.
     *
     * @since 5.9.0
     *
     * @return array
     */
    public function get_custom_templates() {
        $custom_templates = array();
        if ( ! isset( $this->theme_json['customTemplates'] ) || ! is_array( $this->theme_json['customTemplates'] ) ) {
            return $custom_templates;
        }

        foreach ( $this->theme_json['customTemplates'] as $item ) {
            if ( isset( $item['name'] ) ) {
                $custom_templates[ $item['name'] ] = array(
                    'title'     => isset( $item['title'] ) ? $item['title'] : '',
                    'postTypes' => isset( $item['postTypes'] ) ? $item['postTypes'] : array( 'page' ),
                );
            }
        }
        return $custom_templates;
    }

    /**
     * Returns the template part data of active theme.
     *
     * @since 5.9.0
     *
     * @return array
     */
    public function get_template_parts() {
        $template_parts = array();
        if ( ! isset( $this->theme_json['templateParts'] ) || ! is_array( $this->theme_json['templateParts'] ) ) {
            return $template_parts;
        }

        foreach ( $this->theme_json['templateParts'] as $item ) {
            if ( isset( $item['name'] ) ) {
                $template_parts[ $item['name'] ] = array(
                    'title' => isset( $item['title'] ) ? $item['title'] : '',
                    'area'  => isset( $item['area'] ) ? $item['area'] : '',
                );
            }
        }
        return $template_parts;
    }

    /**
     * Converts each style section into a list of rulesets
     * containing the block styles to be appended to the stylesheet.
     *
     * See glossary at https://developer.mozilla.org/en-US/docs/Web/CSS/Syntax
     *
     * For each section this creates a new ruleset such as:
     *
     *   block-selector {
     *     style-property-one: value;
     *   }
     *
     * @since 5.8.0 As `get_block_styles()`.
     * @since 5.9.0 Renamed from `get_block_styles()` to `get_block_classes()`
     *              and no longer returns preset classes.
     *              Removed the `$setting_nodes` parameter.
     * @since 6.1.0 Moved most internal logic to `get_styles_for_block()`.
     *
     * @param array $style_nodes Nodes with styles.
     * @return string The new stylesheet.
     */
    protected function get_block_classes( $style_nodes ) {
        $block_rules = '';

        foreach ( $style_nodes as $metadata ) {
            if ( null === $metadata['selector'] ) {
                continue;
            }
            $block_rules .= static::get_styles_for_block( $metadata );
        }

        return $block_rules;
    }

    /**
     * Gets the CSS layout rules for a particular block from theme.json layout definitions.
     *
     * @since 6.1.0
     * @since 6.3.0 Reduced specificity for layout margin rules.
     * @since 6.5.1 Only output rules referencing content and wide sizes when values exist.
     * @since 6.5.3 Add types parameter to check if only base layout styles are needed.
     *
     * @param array $block_metadata Metadata about the block to get styles for.
     * @param array $types          Optional. Types of styles to output. If empty, all styles will be output.
     * @return string Layout styles for the block.
     */
    protected function get_layout_styles( $block_metadata, $types = array() ) {
        $block_rules = '';
        $block_type  = null;

        // Skip outputting layout styles if explicitly disabled.
        if ( current_theme_supports( 'disable-layout-styles' ) ) {
            return $block_rules;
        }

        if ( isset( $block_metadata['name'] ) ) {
            $block_type = WP_Block_Type_Registry::get_instance()->get_registered( $block_metadata['name'] );
            if ( ! block_has_support( $block_type, 'layout', false ) && ! block_has_support( $block_type, '__experimentalLayout', false ) ) {
                return $block_rules;
            }
        }

        $selector                 = isset( $block_metadata['selector'] ) ? $block_metadata['selector'] : '';
        $has_block_gap_support    = isset( $this->theme_json['settings']['spacing']['blockGap'] );
        $has_fallback_gap_support = ! $has_block_gap_support; // This setting isn't useful yet: it exists as a placeholder for a future explicit fallback gap styles support.
        $node                     = _wp_array_get( $this->theme_json, $block_metadata['path'], array() );
        $layout_definitions       = wp_get_layout_definitions();
        $layout_selector_pattern  = '/^[a-zA-Z0-9\-\.\ *+>:\(\)]*$/'; // Allow alphanumeric classnames, spaces, wildcard, sibling, child combinator and pseudo class selectors.

        /*
         * Gap styles will only be output if the theme has block gap support, or supports a fallback gap.
         * Default layout gap styles will be skipped for themes that do not explicitly opt-in to blockGap with a `true` or `false` value.
         */
        if ( $has_block_gap_support || $has_fallback_gap_support ) {
            $block_gap_value = null;
            // Use a fallback gap value if block gap support is not available.
            if ( ! $has_block_gap_support ) {
                $block_gap_value = static::ROOT_BLOCK_SELECTOR === $selector ? '0.5em' : null;
                if ( ! empty( $block_type ) ) {
                    $block_gap_value = isset( $block_type->supports['spacing']['blockGap']['__experimentalDefault'] )
                        ? $block_type->supports['spacing']['blockGap']['__experimentalDefault']
                        : null;
                }
            } else {
                $block_gap_value = static::get_property_value( $node, array( 'spacing', 'blockGap' ) );
            }

            // Support split row / column values and concatenate to a shorthand value.
            if ( is_array( $block_gap_value ) ) {
                if ( isset( $block_gap_value['top'] ) && isset( $block_gap_value['left'] ) ) {
                    $gap_row         = static::get_property_value( $node, array( 'spacing', 'blockGap', 'top' ) );
                    $gap_column      = static::get_property_value( $node, array( 'spacing', 'blockGap', 'left' ) );
                    $block_gap_value = $gap_row === $gap_column ? $gap_row : $gap_row . ' ' . $gap_column;
                } else {
                    // Skip outputting gap value if not all sides are provided.
                    $block_gap_value = null;
                }
            }

            // If the block should have custom gap, add the gap styles.
            if ( null !== $block_gap_value && false !== $block_gap_value && '' !== $block_gap_value ) {
                foreach ( $layout_definitions as $layout_definition_key => $layout_definition ) {
                    // Allow outputting fallback gap styles for flex and grid layout types when block gap support isn't available.
                    if ( ! $has_block_gap_support && 'flex' !== $layout_definition_key && 'grid' !== $layout_definition_key ) {
                        continue;
                    }

                    $class_name    = isset( $layout_definition['className'] ) ? $layout_definition['className'] : false;
                    $spacing_rules = isset( $layout_definition['spacingStyles'] ) ? $layout_definition['spacingStyles'] : array();

                    if (
                        ! empty( $class_name ) &&
                        ! empty( $spacing_rules )
                    ) {
                        foreach ( $spacing_rules as $spacing_rule ) {
                            $declarations = array();
                            if (
                                isset( $spacing_rule['selector'] ) &&
                                preg_match( $layout_selector_pattern, $spacing_rule['selector'] ) &&
                                ! empty( $spacing_rule['rules'] )
                            ) {
                                // Iterate over each of the styling rules and substitute non-string values such as `null` with the real `blockGap` value.
                                foreach ( $spacing_rule['rules'] as $css_property => $css_value ) {
                                    $current_css_value = is_string( $css_value ) ? $css_value : $block_gap_value;
                                    if ( static::is_safe_css_declaration( $css_property, $current_css_value ) ) {
                                        $declarations[] = array(
                                            'name'  => $css_property,
                                            'value' => $current_css_value,
                                        );
                                    }
                                }

                                if ( ! $has_block_gap_support ) {
                                    // For fallback gap styles, use lower specificity, to ensure styles do not unintentionally override theme styles.
                                    $format          = static::ROOT_BLOCK_SELECTOR === $selector ? ':where(.%2$s%3$s)' : ':where(%1$s.%2$s%3$s)';
                                    $layout_selector = sprintf(
                                        $format,
                                        $selector,
                                        $class_name,
                                        $spacing_rule['selector']
                                    );
                                } else {
                                    $format          = static::ROOT_BLOCK_SELECTOR === $selector ? ':where(%s .%s) %s' : '%s-%s%s';
                                    $layout_selector = sprintf(
                                        $format,
                                        $selector,
                                        $class_name,
                                        $spacing_rule['selector']
                                    );
                                }
                                $block_rules .= static::to_ruleset( $layout_selector, $declarations );
                            }
                        }
                    }
                }
            }
        }

        // Output base styles.
        if (
            static::ROOT_BLOCK_SELECTOR === $selector
        ) {
            $valid_display_modes = array( 'block', 'flex', 'grid' );
            foreach ( $layout_definitions as $layout_definition ) {
                $class_name       = isset( $layout_definition['className'] ) ? $layout_definition['className'] : false;
                $base_style_rules = isset( $layout_definition['baseStyles'] ) ? $layout_definition['baseStyles'] : array();

                if (
                    ! empty( $class_name ) &&
                    is_array( $base_style_rules )
                ) {
                    // Output display mode. This requires special handling as `display` is not exposed in `safe_style_css_filter`.
                    if (
                        ! empty( $layout_definition['displayMode'] ) &&
                        is_string( $layout_definition['displayMode'] ) &&
                        in_array( $layout_definition['displayMode'], $valid_display_modes, true )
                    ) {
                        $layout_selector = sprintf(
                            '%s .%s',
                            $selector,
                            $class_name
                        );
                        $block_rules    .= static::to_ruleset(
                            $layout_selector,
                            array(
                                array(
                                    'name'  => 'display',
                                    'value' => $layout_definition['displayMode'],
                                ),
                            )
                        );
                    }

                    foreach ( $base_style_rules as $base_style_rule ) {
                        $declarations = array();

                        // Skip outputting base styles for flow and constrained layout types if theme doesn't support theme.json. The 'base-layout-styles' type flags this.
                        if ( in_array( 'base-layout-styles', $types, true ) && ( 'default' === $layout_definition['name'] || 'constrained' === $layout_definition['name'] ) ) {
                            continue;
                        }

                        if (
                            isset( $base_style_rule['selector'] ) &&
                            preg_match( $layout_selector_pattern, $base_style_rule['selector'] ) &&
                            ! empty( $base_style_rule['rules'] )
                        ) {
                            foreach ( $base_style_rule['rules'] as $css_property => $css_value ) {
                                // Skip rules that reference content size or wide size if they are not defined in the theme.json.
                                if (
                                    is_string( $css_value ) &&
                                    ( str_contains( $css_value, '--global--content-size' ) || str_contains( $css_value, '--global--wide-size' ) ) &&
                                    ! isset( $this->theme_json['settings']['layout']['contentSize'] ) &&
                                    ! isset( $this->theme_json['settings']['layout']['wideSize'] )
                                ) {
                                    continue;
                                }

                                if ( static::is_safe_css_declaration( $css_property, $css_value ) ) {
                                    $declarations[] = array(
                                        'name'  => $css_property,
                                        'value' => $css_value,
                                    );
                                }
                            }

                            $layout_selector = sprintf(
                                '%s .%s%s',
                                $selector,
                                $class_name,
                                $base_style_rule['selector']
                            );
                            $block_rules    .= static::to_ruleset( $layout_selector, $declarations );
                        }
                    }
                }
            }
        }
        return $block_rules;
    }

    /**
     * Creates new rulesets as classes for each preset value such as:
     *
     *   .has-value-color {
     *     color: value;
     *   }
     *
     *   .has-value-background-color {
     *     background-color: value;
     *   }
     *
     *   .has-value-font-size {
     *     font-size: value;
     *   }
     *
     *   .has-value-gradient-background {
     *     background: value;
     *   }
     *
     *   p.has-value-gradient-background {
     *     background: value;
     *   }
     *
     * @since 5.9.0
     *
     * @param array    $setting_nodes Nodes with settings.
     * @param string[] $origins       List of origins to process presets from.
     * @return string The new stylesheet.
     */
    protected function get_preset_classes( $setting_nodes, $origins ) {
        $preset_rules = '';

        foreach ( $setting_nodes as $metadata ) {
            if ( null === $metadata['selector'] ) {
                continue;
            }

            $selector      = $metadata['selector'];
            $node          = _wp_array_get( $this->theme_json, $metadata['path'], array() );
            $preset_rules .= static::compute_preset_classes( $node, $selector, $origins );
        }

        return $preset_rules;
    }

    /**
     * Converts each styles section into a list of rulesets
     * to be appended to the stylesheet.
     * These rulesets contain all the css variables (custom variables and preset variables).
     *
     * See glossary at https://developer.mozilla.org/en-US/docs/Web/CSS/Syntax
     *
     * For each section this creates a new ruleset such as:
     *
     *     block-selector {
     *       --wp--preset--category--slug: value;
     *       --wp--custom--variable: value;
     *     }
     *
     * @since 5.8.0
     * @since 5.9.0 Added the `$origins` parameter.
     *
     * @param array    $nodes   Nodes with settings.
     * @param string[] $origins List of origins to process.
     * @return string The new stylesheet.
     */
    protected function get_css_variables( $nodes, $origins ) {
        $stylesheet = '';
        foreach ( $nodes as $metadata ) {
            if ( null === $metadata['selector'] ) {
                continue;
            }

            $selector = $metadata['selector'];

            $node                    = _wp_array_get( $this->theme_json, $metadata['path'], array() );
            $declarations            = static::compute_preset_vars( $node, $origins );
            $theme_vars_declarations = static::compute_theme_vars( $node );
            foreach ( $theme_vars_declarations as $theme_vars_declaration ) {
                $declarations[] = $theme_vars_declaration;
            }

            $stylesheet .= static::to_ruleset( $selector, $declarations );
        }

        return $stylesheet;
    }

    /**
     * Given a selector and a declaration list,
     * creates the corresponding ruleset.
     *
     * @since 5.8.0
     *
     * @param string $selector     CSS selector.
     * @param array  $declarations List of declarations.
     * @return string The resulting CSS ruleset.
     */
    protected static function to_ruleset( $selector, $declarations ) {
        if ( empty( $declarations ) ) {
            return '';
        }

        $declaration_block = array_reduce(
            $declarations,
            static function ( $carry, $element ) {
                return $carry .= $element['name'] . ': ' . $element['value'] . ';'; },
            ''
        );

        return $selector . '{' . $declaration_block . '}';
    }

    /**
     * Given a settings array, returns the generated rulesets
     * for the preset classes.
     *
     * @since 5.8.0
     * @since 5.9.0 Added the `$origins` parameter.
     * @since 6.6.0 Added check for root CSS properties selector.
     *
     * @param array    $settings Settings to process.
     * @param string   $selector Selector wrapping the classes.
     * @param string[] $origins  List of origins to process.
     * @return string The result of processing the presets.
     */
    protected static function compute_preset_classes( $settings, $selector, $origins ) {
        if ( static::ROOT_BLOCK_SELECTOR === $selector || static::ROOT_CSS_PROPERTIES_SELECTOR === $selector ) {
            /*
             * Classes at the global level do not need any CSS prefixed,
             * and we don't want to increase its specificity.
             */
            $selector = '';
        }

        $stylesheet = '';
        foreach ( static::PRESETS_METADATA as $preset_metadata ) {
            if ( empty( $preset_metadata['classes'] ) ) {
                continue;
            }
            $slugs = static::get_settings_slugs( $settings, $preset_metadata, $origins );
            foreach ( $preset_metadata['classes'] as $class => $property ) {
                foreach ( $slugs as $slug ) {
                    $css_var    = static::replace_slug_in_string( $preset_metadata['css_vars'], $slug );
                    $class_name = static::replace_slug_in_string( $class, $slug );

                    // $selector is often empty, so we can save ourselves the `append_to_selector()` call then.
                    $new_selector = '' === $selector ? $class_name : static::append_to_selector( $selector, $class_name );
                    $stylesheet  .= static::to_ruleset(
                        $new_selector,
                        array(
                            array(
                                'name'  => $property,
                                'value' => 'var(' . $css_var . ') !important',
                            ),
                        )
                    );
                }
            }
        }

        return $stylesheet;
    }

    /**
     * Function that scopes a selector with another one. This works a bit like
     * SCSS nesting except the `&` operator isn't supported.
     *
     * <code>
     * $scope = '.a, .b .c';
     * $selector = '> .x, .y';
     * $merged = scope_selector( $scope, $selector );
     * // $merged is '.a > .x, .a .y, .b .c > .x, .b .c .y'
     * </code>
     *
     * @since 5.9.0
     *
     * @param string $scope    Selector to scope to.
     * @param string $selector Original selector.
     * @return string Scoped selector.
     */
    public static function scope_selector( $scope, $selector ) {
        $scopes    = explode( ',', $scope );
        $selectors = explode( ',', $selector );

        $selectors_scoped = array();
        foreach ( $scopes as $outer ) {
            foreach ( $selectors as $inner ) {
                $outer = trim( $outer );
                $inner = trim( $inner );
                if ( ! empty( $outer ) && ! empty( $inner ) ) {
                    $selectors_scoped[] = $outer . ' ' . $inner;
                } elseif ( empty( $outer ) ) {
                    $selectors_scoped[] = $inner;
                } elseif ( empty( $inner ) ) {
                    $selectors_scoped[] = $outer;
                }
            }
        }

        $result = implode( ', ', $selectors_scoped );
        return $result;
    }

    /**
     * Gets preset values keyed by slugs based on settings and metadata.
     *
     * <code>
     * $settings = array(
     *     'typography' => array(
     *         'fontFamilies' => array(
     *             array(
     *                 'slug'       => 'sansSerif',
     *                 'fontFamily' => '"Helvetica Neue", sans-serif',
     *             ),
     *             array(
     *                 'slug'   => 'serif',
     *                 'colors' => 'Georgia, serif',
     *             )
     *         ),
     *     ),
     * );
     * $meta = array(
     *    'path'      => array( 'typography', 'fontFamilies' ),
     *    'value_key' => 'fontFamily',
     * );
     * $values_by_slug = get_settings_values_by_slug();
     * // $values_by_slug === array(
     * //   'sans-serif' => '"Helvetica Neue", sans-serif',
     * //   'serif'      => 'Georgia, serif',
     * // );
     * </code>
     *
     * @since 5.9.0
     * @since 6.6.0 Passing $settings to the callbacks defined in static::PRESETS_METADATA.
     *
     * @param array    $settings        Settings to process.
     * @param array    $preset_metadata One of the PRESETS_METADATA values.
     * @param string[] $origins         List of origins to process.
     * @return array Array of presets where each key is a slug and each value is the preset value.
     */
    protected static function get_settings_values_by_slug( $settings, $preset_metadata, $origins ) {
        $preset_per_origin = _wp_array_get( $settings, $preset_metadata['path'], array() );

        $result = array();
        foreach ( $origins as $origin ) {
            if ( ! isset( $preset_per_origin[ $origin ] ) ) {
                continue;
            }
            foreach ( $preset_per_origin[ $origin ] as $preset ) {
                $slug = _wp_to_kebab_case( $preset['slug'] );

                $value = '';
                if ( isset( $preset_metadata['value_key'], $preset[ $preset_metadata['value_key'] ] ) ) {
                    $value_key = $preset_metadata['value_key'];
                    $value     = $preset[ $value_key ];
                } elseif (
                    isset( $preset_metadata['value_func'] ) &&
                    is_callable( $preset_metadata['value_func'] )
                ) {
                    $value_func = $preset_metadata['value_func'];
                    $value      = call_user_func( $value_func, $preset, $settings );
                } else {
                    // If we don't have a value, then don't add it to the result.
                    continue;
                }

                $result[ $slug ] = $value;
            }
        }
        return $result;
    }

    /**
     * Similar to get_settings_values_by_slug, but doesn't compute the value.
     *
     * @since 5.9.0
     *
     * @param array    $settings        Settings to process.
     * @param array    $preset_metadata One of the PRESETS_METADATA values.
     * @param string[] $origins         List of origins to process.
     * @return array Array of presets where the key and value are both the slug.
     */
    protected static function get_settings_slugs( $settings, $preset_metadata, $origins = null ) {
        if ( null === $origins ) {
            $origins = static::VALID_ORIGINS;
        }

        $preset_per_origin = _wp_array_get( $settings, $preset_metadata['path'], array() );

        $result = array();
        foreach ( $origins as $origin ) {
            if ( ! isset( $preset_per_origin[ $origin ] ) ) {
                continue;
            }
            foreach ( $preset_per_origin[ $origin ] as $preset ) {
                $slug = _wp_to_kebab_case( $preset['slug'] );

                // Use the array as a set so we don't get duplicates.
                $result[ $slug ] = $slug;
            }
        }
        return $result;
    }

    /**
     * Transforms a slug into a CSS Custom Property.
     *
     * @since 5.9.0
     *
     * @param string $input String to replace.
     * @param string $slug  The slug value to use to generate the custom property.
     * @return string The CSS Custom Property. Something along the lines of `--wp--preset--color--black`.
     */
    protected static function replace_slug_in_string( $input, $slug ) {
        return strtr( $input, array( '$slug' => $slug ) );
    }

    /**
     * Given the block settings, extracts the CSS Custom Properties
     * for the presets and adds them to the $declarations array
     * following the format:
     *
     *     array(
     *       'name'  => 'property_name',
     *       'value' => 'property_value,
     *     )
     *
     * @since 5.8.0
     * @since 5.9.0 Added the `$origins` parameter.
     *
     * @param array    $settings Settings to process.
     * @param string[] $origins  List of origins to process.
     * @return array The modified $declarations.
     */
    protected static function compute_preset_vars( $settings, $origins ) {
        $declarations = array();
        foreach ( static::PRESETS_METADATA as $preset_metadata ) {
            if ( empty( $preset_metadata['css_vars'] ) ) {
                continue;
            }
            $values_by_slug = static::get_settings_values_by_slug( $settings, $preset_metadata, $origins );
            foreach ( $values_by_slug as $slug => $value ) {
                $declarations[] = array(
                    'name'  => static::replace_slug_in_string( $preset_metadata['css_vars'], $slug ),
                    'value' => $value,
                );
            }
        }

        return $declarations;
    }

    /**
     * Given an array of settings, extracts the CSS Custom Properties
     * for the custom values and adds them to the $declarations
     * array following the format:
     *
     *     array(
     *       'name'  => 'property_name',
     *       'value' => 'property_value,
     *     )
     *
     * @since 5.8.0
     *
     * @param array $settings Settings to process.
     * @return array The modified $declarations.
     */
    protected static function compute_theme_vars( $settings ) {
        $declarations  = array();
        $custom_values = isset( $settings['custom'] ) ? $settings['custom'] : array();
        $css_vars      = static::flatten_tree( $custom_values );
        foreach ( $css_vars as $key => $value ) {
            $declarations[] = array(
                'name'  => '--wp--custom--' . $key,
                'value' => $value,
            );
        }

        return $declarations;
    }

    /**
     * Given a tree, it creates a flattened one
     * by merging the keys and binding the leaf values
     * to the new keys.
     *
     * It also transforms camelCase names into kebab-case
     * and substitutes '/' by '-'.
     *
     * This is thought to be useful to generate
     * CSS Custom Properties from a tree,
     * although there's nothing in the implementation
     * of this function that requires that format.
     *
     * For example, assuming the given prefix is '--wp'
     * and the token is '--', for this input tree:
     *
     *     {
     *       'some/property': 'value',
     *       'nestedProperty': {
     *         'sub-property': 'value'
     *       }
     *     }
     *
     * it'll return this output:
     *
     *     {
     *       '--wp--some-property': 'value',
     *       '--wp--nested-property--sub-property': 'value'
     *     }
     *
     * @since 5.8.0
     *
     * @param array  $tree   Input tree to process.
     * @param string $prefix Optional. Prefix to prepend to each variable. Default empty string.
     * @param string $token  Optional. Token to use between levels. Default '--'.
     * @return array The flattened tree.
     */
    protected static function flatten_tree( $tree, $prefix = '', $token = '--' ) {
        $result = array();
        foreach ( $tree as $property => $value ) {
            $new_key = $prefix . str_replace(
                '/',
                '-',
                strtolower( _wp_to_kebab_case( $property ) )
            );

            if ( is_array( $value ) ) {
                $new_prefix        = $new_key . $token;
                $flattened_subtree = static::flatten_tree( $value, $new_prefix, $token );
                foreach ( $flattened_subtree as $subtree_key => $subtree_value ) {
                    $result[ $subtree_key ] = $subtree_value;
                }
            } else {
                $result[ $new_key ] = $value;
            }
        }
        return $result;
    }

    /**
     * Given a styles array, it extracts the style properties
     * and adds them to the $declarations array following the format:
     *
     *     array(
     *       'name'  => 'property_name',
     *       'value' => 'property_value,
     *     )
     *
     * @since 5.8.0
     * @since 5.9.0 Added the `$settings` and `$properties` parameters.
     * @since 6.1.0 Added `$theme_json`, `$selector`, and `$use_root_padding` parameters.
     * @since 6.5.0 Output a `min-height: unset` rule when `aspect-ratio` is set.
     * @since 6.6.0 Pass current theme JSON settings to wp_get_typography_font_size_value(), and process background properties.
     *
     * @param array   $styles Styles to process.
     * @param array   $settings Theme settings.
     * @param array   $properties Properties metadata.
     * @param array   $theme_json Theme JSON array.
     * @param string  $selector The style block selector.
     * @param boolean $use_root_padding Whether to add custom properties at root level.
     * @return array  Returns the modified $declarations.
     */
    protected static function compute_style_properties( $styles, $settings = array(), $properties = null, $theme_json = null, $selector = null, $use_root_padding = null ) {
        if ( null === $properties ) {
            $properties = static::PROPERTIES_METADATA;
        }

        $declarations = array();
        if ( empty( $styles ) ) {
            return $declarations;
        }

        $root_variable_duplicates = array();

        foreach ( $properties as $css_property => $value_path ) {
            $value = static::get_property_value( $styles, $value_path, $theme_json );

            if ( str_starts_with( $css_property, '--wp--style--root--' ) && ( static::ROOT_BLOCK_SELECTOR !== $selector || ! $use_root_padding ) ) {
                continue;
            }
            /*
             * Root-level padding styles don't currently support strings with CSS shorthand values.
             * This may change: https://github.com/WordPress/gutenberg/issues/40132.
             */
            if ( '--wp--style--root--padding' === $css_property && is_string( $value ) ) {
                continue;
            }

            if ( str_starts_with( $css_property, '--wp--style--root--' ) && $use_root_padding ) {
                $root_variable_duplicates[] = substr( $css_property, strlen( '--wp--style--root--' ) );
            }

            /*
             * Look up protected properties, keyed by value path.
             * Skip protected properties that are explicitly set to `null`.
             */
            if ( is_array( $value_path ) ) {
                $path_string = implode( '.', $value_path );
                if (
                    isset( static::PROTECTED_PROPERTIES[ $path_string ] ) &&
                    _wp_array_get( $settings, static::PROTECTED_PROPERTIES[ $path_string ], null ) === null
                ) {
                    continue;
                }
            }

            // Processes background styles.
            if ( 'background' === $value_path[0] && isset( $styles['background'] ) ) {
                $background_styles = wp_style_engine_get_styles( array( 'background' => $styles['background'] ) );
                $value             = isset( $background_styles['declarations'][ $css_property ] ) ? $background_styles['declarations'][ $css_property ] : $value;
            }

            // Skip if empty and not "0" or value represents array of longhand values.
            $has_missing_value = empty( $value ) && ! is_numeric( $value );
            if ( $has_missing_value || is_array( $value ) ) {
                continue;
            }

            // Calculates fluid typography rules where available.
            if ( 'font-size' === $css_property ) {
                /*
                 * wp_get_typography_font_size_value() will check
                 * if fluid typography has been activated and also
                 * whether the incoming value can be converted to a fluid value.
                 * Values that already have a clamp() function will not pass the test,
                 * and therefore the original $value will be returned.
                 * Pass the current theme_json settings to override any global settings.
                 */
                $value = wp_get_typography_font_size_value( array( 'size' => $value ), $settings );
            }

            if ( 'aspect-ratio' === $css_property ) {
                // For aspect ratio to work, other dimensions rules must be unset.
                // This ensures that a fixed height does not override the aspect ratio.
                $declarations[] = array(
                    'name'  => 'min-height',
                    'value' => 'unset',
                );
            }

            $declarations[] = array(
                'name'  => $css_property,
                'value' => $value,
            );
        }

        // If a variable value is added to the root, the corresponding property should be removed.
        foreach ( $root_variable_duplicates as $duplicate ) {
            $discard = array_search( $duplicate, array_column( $declarations, 'name' ), true );
            if ( is_numeric( $discard ) ) {
                array_splice( $declarations, $discard, 1 );
            }
        }

        return $declarations;
    }

    /**
     * Returns the style property for the given path.
     *
     * It also converts references to a path to the value
     * stored at that location, e.g.
     * { "ref": "style.color.background" } => "#fff".
     *
     * @since 5.8.0
     * @since 5.9.0 Added support for values of array type, which are returned as is.
     * @since 6.1.0 Added the `$theme_json` parameter.
     * @since 6.3.0 It no longer converts the internal format "var:preset|color|secondary"
     *              to the standard form "--wp--preset--color--secondary".
     *              This is already done by the sanitize method,
     *              so every property will be in the standard form.
     *
     * @param array $styles Styles subtree.
     * @param array $path   Which property to process.
     * @param array $theme_json Theme JSON array.
     * @return string|array Style property value.
     */
    protected static function get_property_value( $styles, $path, $theme_json = null ) {
        $value = _wp_array_get( $styles, $path, '' );

        if ( '' === $value || null === $value ) {
            // No need to process the value further.
            return '';
        }

        /*
         * This converts references to a path to the value at that path
         * where the values is an array with a "ref" key, pointing to a path.
         * For example: { "ref": "style.color.background" } => "#fff".
         */
        if ( is_array( $value ) && isset( $value['ref'] ) ) {
            $value_path = explode( '.', $value['ref'] );
            $ref_value  = _wp_array_get( $theme_json, $value_path );
            // Only use the ref value if we find anything.
            if ( ! empty( $ref_value ) && is_string( $ref_value ) ) {
                $value = $ref_value;
            }

            if ( is_array( $ref_value ) && isset( $ref_value['ref'] ) ) {
                $path_string      = json_encode( $path );
                $ref_value_string = json_encode( $ref_value );
                _doing_it_wrong(
                    'get_property_value',
                    sprintf(
                        /* translators: 1: theme.json, 2: Value name, 3: Value path, 4: Another value name. */
                        __( 'Your %1$s file uses a dynamic value (%2$s) for the path at %3$s. However, the value at %3$s is also a dynamic value (pointing to %4$s) and pointing to another dynamic value is not supported. Please update %3$s to point directly to %4$s.' ),
                        'theme.json',
                        $ref_value_string,
                        $path_string,
                        $ref_value['ref']
                    ),
                    '6.1.0'
                );
            }
        }

        if ( is_array( $value ) ) {
            return $value;
        }

        return $value;
    }

    /**
     * Builds metadata for the setting nodes, which returns in the form of:
     *
     *     [
     *       [
     *         'path'     => ['path', 'to', 'some', 'node' ],
     *         'selector' => 'CSS selector for some node'
     *       ],
     *       [
     *         'path'     => [ 'path', 'to', 'other', 'node' ],
     *         'selector' => 'CSS selector for other node'
     *       ],
     *     ]
     *
     * @since 5.8.0
     *
     * @param array $theme_json The tree to extract setting nodes from.
     * @param array $selectors  List of selectors per block.
     * @return array An array of setting nodes metadata.
     */
    protected static function get_setting_nodes( $theme_json, $selectors = array() ) {
        $nodes = array();
        if ( ! isset( $theme_json['settings'] ) ) {
            return $nodes;
        }

        // Top-level.
        $nodes[] = array(
            'path'     => array( 'settings' ),
            'selector' => static::ROOT_CSS_PROPERTIES_SELECTOR,
        );

        // Calculate paths for blocks.
        if ( ! isset( $theme_json['settings']['blocks'] ) ) {
            return $nodes;
        }

        foreach ( $theme_json['settings']['blocks'] as $name => $node ) {
            $selector = null;
            if ( isset( $selectors[ $name ]['selector'] ) ) {
                $selector = $selectors[ $name ]['selector'];
            }

            $nodes[] = array(
                'path'     => array( 'settings', 'blocks', $name ),
                'selector' => $selector,
            );
        }

        return $nodes;
    }

    /**
     * Builds metadata for the style nodes, which returns in the form of:
     *
     *     [
     *       [
     *         'path'     => [ 'path', 'to', 'some', 'node' ],
     *         'selector' => 'CSS selector for some node',
     *         'duotone'  => 'CSS selector for duotone for some node'
     *       ],
     *       [
     *         'path'     => ['path', 'to', 'other', 'node' ],
     *         'selector' => 'CSS selector for other node',
     *         'duotone'  => null
     *       ],
     *     ]
     *
     * @since 5.8.0
     *
     * @param array $theme_json The tree to extract style nodes from.
     * @param array $selectors  List of selectors per block.
     * @return array An array of style nodes metadata.
     */
    protected static function get_style_nodes( $theme_json, $selectors = array() ) {
        $nodes = array();
        if ( ! isset( $theme_json['styles'] ) ) {
            return $nodes;
        }

        // Top-level.
        $nodes[] = array(
            'path'     => array( 'styles' ),
            'selector' => static::ROOT_BLOCK_SELECTOR,
        );

        if ( isset( $theme_json['styles']['elements'] ) ) {
            foreach ( self::ELEMENTS as $element => $selector ) {
                if ( ! isset( $theme_json['styles']['elements'][ $element ] ) ) {
                    continue;
                }
                $nodes[] = array(
                    'path'     => array( 'styles', 'elements', $element ),
                    'selector' => static::ELEMENTS[ $element ],
                );

                // Handle any pseudo selectors for the element.
                if ( isset( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $element ] ) ) {
                    foreach ( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $element ] as $pseudo_selector ) {

                        if ( isset( $theme_json['styles']['elements'][ $element ][ $pseudo_selector ] ) ) {
                            $nodes[] = array(
                                'path'     => array( 'styles', 'elements', $element ),
                                'selector' => static::append_to_selector( static::ELEMENTS[ $element ], $pseudo_selector ),
                            );
                        }
                    }
                }
            }
        }

        // Blocks.
        if ( ! isset( $theme_json['styles']['blocks'] ) ) {
            return $nodes;
        }

        $block_nodes = static::get_block_nodes( $theme_json );
        foreach ( $block_nodes as $block_node ) {
            $nodes[] = $block_node;
        }

        /**
         * Filters the list of style nodes with metadata.
         *
         * This allows for things like loading block CSS independently.
         *
         * @since 6.1.0
         *
         * @param array $nodes Style nodes with metadata.
         */
        return apply_filters( 'wp_theme_json_get_style_nodes', $nodes );
    }

    /**
     * A public helper to get the block nodes from a theme.json file.
     *
     * @since 6.1.0
     *
     * @return array The block nodes in theme.json.
     */
    public function get_styles_block_nodes() {
        return static::get_block_nodes( $this->theme_json );
    }

    /**
     * Returns a filtered declarations array if there is a separator block with only a background
     * style defined in theme.json by adding a color attribute to reflect the changes in the front.
     *
     * @since 6.1.1
     *
     * @param array $declarations List of declarations.
     * @return array $declarations List of declarations filtered.
     */
    private static function update_separator_declarations( $declarations ) {
        $background_color     = '';
        $border_color_matches = false;
        $text_color_matches   = false;

        foreach ( $declarations as $declaration ) {
            if ( 'background-color' === $declaration['name'] && ! $background_color && isset( $declaration['value'] ) ) {
                $background_color = $declaration['value'];
            } elseif ( 'border-color' === $declaration['name'] ) {
                $border_color_matches = true;
            } elseif ( 'color' === $declaration['name'] ) {
                $text_color_matches = true;
            }

            if ( $background_color && $border_color_matches && $text_color_matches ) {
                break;
            }
        }

        if ( $background_color && ! $border_color_matches && ! $text_color_matches ) {
            $declarations[] = array(
                'name'  => 'color',
                'value' => $background_color,
            );
        }

        return $declarations;
    }

    /**
     * An internal method to get the block nodes from a theme.json file.
     *
     * @since 6.1.0
     * @since 6.3.0 Refactored and stabilized selectors API.
     *
     * @param array $theme_json The theme.json converted to an array.
     * @return array The block nodes in theme.json.
     */
    private static function get_block_nodes( $theme_json ) {
        $selectors = static::get_blocks_metadata();
        $nodes     = array();
        if ( ! isset( $theme_json['styles'] ) ) {
            return $nodes;
        }

        // Blocks.
        if ( ! isset( $theme_json['styles']['blocks'] ) ) {
            return $nodes;
        }

        foreach ( $theme_json['styles']['blocks'] as $name => $node ) {
            $selector = null;
            if ( isset( $selectors[ $name ]['selector'] ) ) {
                $selector = $selectors[ $name ]['selector'];
            }

            $duotone_selector = null;
            if ( isset( $selectors[ $name ]['duotone'] ) ) {
                $duotone_selector = $selectors[ $name ]['duotone'];
            }

            $feature_selectors = null;
            if ( isset( $selectors[ $name ]['selectors'] ) ) {
                $feature_selectors = $selectors[ $name ]['selectors'];
            }

            $variation_selectors = array();
            if ( isset( $node['variations'] ) ) {
                foreach ( $node['variations'] as $variation => $node ) {
                    $variation_selectors[] = array(
                        'path'     => array( 'styles', 'blocks', $name, 'variations', $variation ),
                        'selector' => $selectors[ $name ]['styleVariations'][ $variation ],
                    );
                }
            }

            $nodes[] = array(
                'name'       => $name,
                'path'       => array( 'styles', 'blocks', $name ),
                'selector'   => $selector,
                'selectors'  => $feature_selectors,
                'duotone'    => $duotone_selector,
                'features'   => $feature_selectors,
                'variations' => $variation_selectors,
            );

            if ( isset( $theme_json['styles']['blocks'][ $name ]['elements'] ) ) {
                foreach ( $theme_json['styles']['blocks'][ $name ]['elements'] as $element => $node ) {
                    $nodes[] = array(
                        'path'     => array( 'styles', 'blocks', $name, 'elements', $element ),
                        'selector' => $selectors[ $name ]['elements'][ $element ],
                    );

                    // Handle any pseudo selectors for the element.
                    if ( isset( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $element ] ) ) {
                        foreach ( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $element ] as $pseudo_selector ) {
                            if ( isset( $theme_json['styles']['blocks'][ $name ]['elements'][ $element ][ $pseudo_selector ] ) ) {
                                $nodes[] = array(
                                    'path'     => array( 'styles', 'blocks', $name, 'elements', $element ),
                                    'selector' => static::append_to_selector( $selectors[ $name ]['elements'][ $element ], $pseudo_selector ),
                                );
                            }
                        }
                    }
                }
            }
        }

        return $nodes;
    }

    /**
     * Gets the CSS rules for a particular block from theme.json.
     *
     * @since 6.1.0
     * @since 6.6.0 Setting a min-height of HTML when root styles have a background gradient or image.
     *
     * @param array $block_metadata Metadata about the block to get styles for.
     *
     * @return string Styles for the block.
     */
    public function get_styles_for_block( $block_metadata ) {
        $node                 = _wp_array_get( $this->theme_json, $block_metadata['path'], array() );
        $use_root_padding     = isset( $this->theme_json['settings']['useRootPaddingAwareAlignments'] ) && true === $this->theme_json['settings']['useRootPaddingAwareAlignments'];
        $selector             = $block_metadata['selector'];
        $settings             = isset( $this->theme_json['settings'] ) ? $this->theme_json['settings'] : array();
        $feature_declarations = static::get_feature_declarations_for_node( $block_metadata, $node );
        $is_root_selector     = static::ROOT_BLOCK_SELECTOR === $selector;

        // If there are style variations, generate the declarations for them, including any feature selectors the block may have.
        $style_variation_declarations = array();
        if ( ! empty( $block_metadata['variations'] ) ) {
            foreach ( $block_metadata['variations'] as $style_variation ) {
                $style_variation_node           = _wp_array_get( $this->theme_json, $style_variation['path'], array() );
                $clean_style_variation_selector = trim( $style_variation['selector'] );

                // Generate any feature/subfeature style declarations for the current style variation.
                $variation_declarations = static::get_feature_declarations_for_node( $block_metadata, $style_variation_node );

                // Combine selectors with style variation's selector and add to overall style variation declarations.
                foreach ( $variation_declarations as $current_selector => $new_declarations ) {
                    // If current selector includes block classname, remove it but leave the whitespace in.
                    $shortened_selector = str_replace( $block_metadata['selector'] . ' ', ' ', $current_selector );

                    // Prepend the variation selector to the current selector.
                    $split_selectors    = explode( ',', $shortened_selector );
                    $updated_selectors  = array_map(
                        static function ( $split_selector ) use ( $clean_style_variation_selector ) {
                            return $clean_style_variation_selector . $split_selector;
                        },
                        $split_selectors
                    );
                    $combined_selectors = implode( ',', $updated_selectors );

                    // Add the new declarations to the overall results under the modified selector.
                    $style_variation_declarations[ $combined_selectors ] = $new_declarations;
                }

                // Compute declarations for remaining styles not covered by feature level selectors.
                $style_variation_declarations[ $style_variation['selector'] ] = static::compute_style_properties( $style_variation_node, $settings, null, $this->theme_json );
            }
        }
        /*
         * Get a reference to element name from path.
         * $block_metadata['path'] = array( 'styles','elements','link' );
         * Make sure that $block_metadata['path'] describes an element node, like [ 'styles', 'element', 'link' ].
         * Skip non-element paths like just ['styles'].
         */
        $is_processing_element = in_array( 'elements', $block_metadata['path'], true );

        $current_element = $is_processing_element ? $block_metadata['path'][ count( $block_metadata['path'] ) - 1 ] : null;

        $element_pseudo_allowed = array();

        if ( isset( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $current_element ] ) ) {
            $element_pseudo_allowed = static::VALID_ELEMENT_PSEUDO_SELECTORS[ $current_element ];
        }

        /*
         * Check for allowed pseudo classes (e.g. ":hover") from the $selector ("a:hover").
         * This also resets the array keys.
         */
        $pseudo_matches = array_values(
            array_filter(
                $element_pseudo_allowed,
                static function ( $pseudo_selector ) use ( $selector ) {
                    return str_contains( $selector, $pseudo_selector );
                }
            )
        );

        $pseudo_selector = isset( $pseudo_matches[0] ) ? $pseudo_matches[0] : null;

        /*
         * If the current selector is a pseudo selector that's defined in the allow list for the current
         * element then compute the style properties for it.
         * Otherwise just compute the styles for the default selector as normal.
         */
        if ( $pseudo_selector && isset( $node[ $pseudo_selector ] ) &&
            isset( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $current_element ] )
            && in_array( $pseudo_selector, static::VALID_ELEMENT_PSEUDO_SELECTORS[ $current_element ], true )
        ) {
            $declarations = static::compute_style_properties( $node[ $pseudo_selector ], $settings, null, $this->theme_json, $selector, $use_root_padding );
        } else {
            $declarations = static::compute_style_properties( $node, $settings, null, $this->theme_json, $selector, $use_root_padding );
        }

        $block_rules = '';

        /*
         * 1. Bespoke declaration modifiers:
         * - 'filter': Separate the declarations that use the general selector
         * from the ones using the duotone selector.
         * - 'background|background-image': set the html min-height to 100%
         * to ensure the background covers the entire viewport.
         */
        $declarations_duotone       = array();
        $should_set_root_min_height = false;

        foreach ( $declarations as $index => $declaration ) {
            if ( 'filter' === $declaration['name'] ) {
                /*
                 * 'unset' filters happen when a filter is unset
                 * in the site-editor UI. Because the 'unset' value
                 * in the user origin overrides the value in the
                 * theme origin, we can skip rendering anything
                 * here as no filter needs to be applied anymore.
                 * So only add declarations to with values other
                 * than 'unset'.
                 */
                if ( 'unset' !== $declaration['value'] ) {
                    $declarations_duotone[] = $declaration;
                }
                unset( $declarations[ $index ] );
            }

            if ( $is_root_selector && ( 'background-image' === $declaration['name'] || 'background' === $declaration['name'] ) ) {
                $should_set_root_min_height = true;
            }
        }

        /*
         * If root styles has a background-image or a background (gradient) set,
         * set the min-height to '100%'. Minus `--wp-admin--admin-bar--height` for logged-in view.
         * Setting the CSS rule on the HTML tag ensures background gradients and images behave similarly,
         * and matches the behavior of the site editor.
         */
        if ( $should_set_root_min_height ) {
            $block_rules .= static::to_ruleset(
                'html',
                array(
                    array(
                        'name'  => 'min-height',
                        'value' => 'calc(100% - var(--wp-admin--admin-bar--height, 0px))',
                    ),
                )
            );
        }

        // Update declarations if there are separators with only background color defined.
        if ( '.wp-block-separator' === $selector ) {
            $declarations = static::update_separator_declarations( $declarations );
        }

        // 2. Generate and append the rules that use the general selector.
        $block_rules .= static::to_ruleset( $selector, $declarations );

        // 3. Generate and append the rules that use the duotone selector.
        if ( isset( $block_metadata['duotone'] ) && ! empty( $declarations_duotone ) ) {
            $block_rules .= static::to_ruleset( $block_metadata['duotone'], $declarations_duotone );
        }

        // 4. Generate Layout block gap styles.
        if (
            ! $is_root_selector &&
            ! empty( $block_metadata['name'] )
        ) {
            $block_rules .= $this->get_layout_styles( $block_metadata );
        }

        // 5. Generate and append the feature level rulesets.
        foreach ( $feature_declarations as $feature_selector => $individual_feature_declarations ) {
            $block_rules .= static::to_ruleset( $feature_selector, $individual_feature_declarations );
        }

        // 6. Generate and append the style variation rulesets.
        foreach ( $style_variation_declarations as $style_variation_selector => $individual_style_variation_declarations ) {
            $block_rules .= static::to_ruleset( $style_variation_selector, $individual_style_variation_declarations );
        }

        return $block_rules;
    }

    /**
     * Outputs the CSS for layout rules on the root.
     *
     * @since 6.1.0
     * @since 6.6.0 Use `ROOT_CSS_PROPERTIES_SELECTOR` for CSS custom properties and improved consistency of root padding rules.
     *
     * @param string $selector The root node selector.
     * @param array  $block_metadata The metadata for the root block.
     * @return string The additional root rules CSS.
     */
    public function get_root_layout_rules( $selector, $block_metadata ) {
        $css              = '';
        $settings         = isset( $this->theme_json['settings'] ) ? $this->theme_json['settings'] : array();
        $use_root_padding = isset( $this->theme_json['settings']['useRootPaddingAwareAlignments'] ) && true === $this->theme_json['settings']['useRootPaddingAwareAlignments'];

        /*
        * If there are content and wide widths in theme.json, output them
        * as custom properties on the body element so all blocks can use them.
        */
        if ( isset( $settings['layout']['contentSize'] ) || isset( $settings['layout']['wideSize'] ) ) {
            $content_size = isset( $settings['layout']['contentSize'] ) ? $settings['layout']['contentSize'] : $settings['layout']['wideSize'];
            $content_size = static::is_safe_css_declaration( 'max-width', $content_size ) ? $content_size : 'initial';
            $wide_size    = isset( $settings['layout']['wideSize'] ) ? $settings['layout']['wideSize'] : $settings['layout']['contentSize'];
            $wide_size    = static::is_safe_css_declaration( 'max-width', $wide_size ) ? $wide_size : 'initial';
            $css         .= static::ROOT_CSS_PROPERTIES_SELECTOR . ' { --wp--style--global--content-size: ' . $content_size . ';';
            $css         .= '--wp--style--global--wide-size: ' . $wide_size . '; }';
        }

        /*
        * Reset default browser margin on the body element.
        * This is set on the body selector **before** generating the ruleset
        * from the `theme.json`. This is to ensure that if the `theme.json` declares
        * `margin` in its `spacing` declaration for the `body` element then these
        * user-generated values take precedence in the CSS cascade.
        * @link https://github.com/WordPress/gutenberg/issues/36147.
        */
        $css .= 'body { margin: 0; }';

        if ( $use_root_padding ) {
            // Top and bottom padding are applied to the outer block container.
            $css .= '.wp-site-blocks { padding-top: var(--wp--style--root--padding-top); padding-bottom: var(--wp--style--root--padding-bottom); }';
            // Right and left padding are applied to the first container with `.has-global-padding` class.
            $css .= '.has-global-padding { padding-right: var(--wp--style--root--padding-right); padding-left: var(--wp--style--root--padding-left); }';
            // Alignfull children of the container with left and right padding have negative margins so they can still be full width.
            $css .= '.has-global-padding > .alignfull { margin-right: calc(var(--wp--style--root--padding-right) * -1); margin-left: calc(var(--wp--style--root--padding-left) * -1); }';
            // Nested children of the container with left and right padding that are not wide or full aligned do not get padding.
            $css .= '.has-global-padding :where(.has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) { padding-right: 0; padding-left: 0; }';
            // Nested children of the container with left and right padding that are not wide or full aligned do not get negative margin applied.
            $css .= '.has-global-padding :where(.has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) > .alignfull { margin-left: 0; margin-right: 0; }';
        }

        $css .= '.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }';
        $css .= '.wp-site-blocks > .alignright { float: right; margin-left: 2em; }';
        $css .= '.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }';

        // Block gap styles will be output unless explicitly set to `null`. See static::PROTECTED_PROPERTIES.
        if ( isset( $this->theme_json['settings']['spacing']['blockGap'] ) ) {
            $block_gap_value = static::get_property_value( $this->theme_json, array( 'styles', 'spacing', 'blockGap' ) );
            $css            .= ":where(.wp-site-blocks) > * { margin-block-start: $block_gap_value; margin-block-end: 0; }";
            $css            .= ':where(.wp-site-blocks) > :first-child:first-child { margin-block-start: 0; }';
            $css            .= ':where(.wp-site-blocks) > :last-child:last-child { margin-block-end: 0; }';

            // For backwards compatibility, ensure the legacy block gap CSS variable is still available.
            $css .= static::ROOT_CSS_PROPERTIES_SELECTOR . " { --wp--style--block-gap: $block_gap_value; }";
        }
        $css .= $this->get_layout_styles( $block_metadata );

        return $css;
    }

    /**
     * For metadata values that can either be booleans or paths to booleans, gets the value.
     *
     *     $data = array(
     *       'color' => array(
     *         'defaultPalette' => true
     *       )
     *     );
     *
     *     static::get_metadata_boolean( $data, false );
     *     // => false
     *
     *     static::get_metadata_boolean( $data, array( 'color', 'defaultPalette' ) );
     *     // => true
     *
     * @since 6.0.0
     *
     * @param array      $data          The data to inspect.
     * @param bool|array $path          Boolean or path to a boolean.
     * @param bool       $default_value Default value if the referenced path is missing.
     *                                  Default false.
     * @return bool Value of boolean metadata.
     */
    protected static function get_metadata_boolean( $data, $path, $default_value = false ) {
        if ( is_bool( $path ) ) {
            return $path;
        }

        if ( is_array( $path ) ) {
            $value = _wp_array_get( $data, $path );
            if ( null !== $value ) {
                return $value;
            }
        }

        return $default_value;
    }

    /**
     * Merges new incoming data.
     *
     * @since 5.8.0
     * @since 5.9.0 Duotone preset also has origins.
     *
     * @param WP_Theme_JSON $incoming Data to merge.
     */
    public function merge( $incoming ) {
        $incoming_data    = $incoming->get_raw_data();
        $this->theme_json = array_replace_recursive( $this->theme_json, $incoming_data );

        /*
         * The array_replace_recursive algorithm merges at the leaf level,
         * but we don't want leaf arrays to be merged, so we overwrite it.
         *
         * For leaf values that are sequential arrays it will use the numeric indexes for replacement.
         * We rather replace the existing with the incoming value, if it exists.
         * This is the case of spacing.units.
         *
         * For leaf values that are associative arrays it will merge them as expected.
         * This is also not the behavior we want for the current associative arrays (presets).
         * We rather replace the existing with the incoming value, if it exists.
         * This happens, for example, when we merge data from theme.json upon existing
         * theme supports or when we merge anything coming from the same source twice.
         * This is the case of color.palette, color.gradients, color.duotone,
         * typography.fontSizes, or typography.fontFamilies.
         *
         * Additionally, for some preset types, we also want to make sure the
         * values they introduce don't conflict with default values. We do so
         * by checking the incoming slugs for theme presets and compare them
         * with the equivalent default presets: if a slug is present as a default
         * we remove it from the theme presets.
         */
        $nodes        = static::get_setting_nodes( $incoming_data );
        $slugs_global = static::get_default_slugs( $this->theme_json, array( 'settings' ) );
        foreach ( $nodes as $node ) {
            // Replace the spacing.units.
            $path   = $node['path'];
            $path[] = 'spacing';
            $path[] = 'units';

            $content = _wp_array_get( $incoming_data, $path, null );
            if ( isset( $content ) ) {
                _wp_array_set( $this->theme_json, $path, $content );
            }

            // Replace the presets.
            foreach ( static::PRESETS_METADATA as $preset ) {
                $override_preset = ! static::get_metadata_boolean( $this->theme_json['settings'], $preset['prevent_override'], true );

                foreach ( static::VALID_ORIGINS as $origin ) {
                    $base_path = $node['path'];
                    foreach ( $preset['path'] as $leaf ) {
                        $base_path[] = $leaf;
                    }

                    $path   = $base_path;
                    $path[] = $origin;

                    $content = _wp_array_get( $incoming_data, $path, null );
                    if ( ! isset( $content ) ) {
                        continue;
                    }

                    if ( 'theme' === $origin && $preset['use_default_names'] ) {
                        foreach ( $content as $key => $item ) {
                            if ( ! isset( $item['name'] ) ) {
                                $name = static::get_name_from_defaults( $item['slug'], $base_path );
                                if ( null !== $name ) {
                                    $content[ $key ]['name'] = $name;
                                }
                            }
                        }
                    }

                    if (
                        ( 'theme' !== $origin ) ||
                        ( 'theme' === $origin && $override_preset )
                    ) {
                        _wp_array_set( $this->theme_json, $path, $content );
                    } else {
                        $slugs_node = static::get_default_slugs( $this->theme_json, $node['path'] );
                        $slugs      = array_merge_recursive( $slugs_global, $slugs_node );

                        $slugs_for_preset = _wp_array_get( $slugs, $preset['path'], array() );
                        $content          = static::filter_slugs( $content, $slugs_for_preset );
                        _wp_array_set( $this->theme_json, $path, $content );
                    }
                }
            }
        }
    }

    /**
     * Converts all filter (duotone) presets into SVGs.
     *
     * @since 5.9.1
     *
     * @param array $origins List of origins to process.
     * @return string SVG filters.
     */
    public function get_svg_filters( $origins ) {
        $blocks_metadata = static::get_blocks_metadata();
        $setting_nodes   = static::get_setting_nodes( $this->theme_json, $blocks_metadata );

        $filters = '';
        foreach ( $setting_nodes as $metadata ) {
            $node = _wp_array_get( $this->theme_json, $metadata['path'], array() );
            if ( empty( $node['color']['duotone'] ) ) {
                continue;
            }

            $duotone_presets = $node['color']['duotone'];

            foreach ( $origins as $origin ) {
                if ( ! isset( $duotone_presets[ $origin ] ) ) {
                    continue;
                }
                foreach ( $duotone_presets[ $origin ] as $duotone_preset ) {
                    $filters .= wp_get_duotone_filter_svg( $duotone_preset );
                }
            }
        }

        return $filters;
    }

    /**
     * Determines whether a presets should be overridden or not.
     *
     * @since 5.9.0
     * @deprecated 6.0.0 Use {@see 'get_metadata_boolean'} instead.
     *
     * @param array      $theme_json The theme.json like structure to inspect.
     * @param array      $path       Path to inspect.
     * @param bool|array $override   Data to compute whether to override the preset.
     * @return bool
     */
    protected static function should_override_preset( $theme_json, $path, $override ) {
        _deprecated_function( __METHOD__, '6.0.0', 'get_metadata_boolean' );

        if ( is_bool( $override ) ) {
            return $override;
        }

        /*
         * The relationship between whether to override the defaults
         * and whether the defaults are enabled is inverse:
         *
         * - If defaults are enabled  => theme presets should not be overridden
         * - If defaults are disabled => theme presets should be overridden
         *
         * For example, a theme sets defaultPalette to false,
         * making the default palette hidden from the user.
         * In that case, we want all the theme presets to be present,
         * so they should override the defaults.
         */
        if ( is_array( $override ) ) {
            $value = _wp_array_get( $theme_json, array_merge( $path, $override ) );
            if ( isset( $value ) ) {
                return ! $value;
            }

            // Search the top-level key if none was found for this node.
            $value = _wp_array_get( $theme_json, array_merge( array( 'settings' ), $override ) );
            if ( isset( $value ) ) {
                return ! $value;
            }

            return true;
        }
    }

    /**
     * Returns the default slugs for all the presets in an associative array
     * whose keys are the preset paths and the leaves is the list of slugs.
     *
     * For example:
     *
     *     array(
     *       'color' => array(
     *         'palette'   => array( 'slug-1', 'slug-2' ),
     *         'gradients' => array( 'slug-3', 'slug-4' ),
     *       ),
     *     )
     *
     * @since 5.9.0
     *
     * @param array $data      A theme.json like structure.
     * @param array $node_path The path to inspect. It's 'settings' by default.
     * @return array
     */
    protected static function get_default_slugs( $data, $node_path ) {
        $slugs = array();

        foreach ( static::PRESETS_METADATA as $metadata ) {
            $path = $node_path;
            foreach ( $metadata['path'] as $leaf ) {
                $path[] = $leaf;
            }
            $path[] = 'default';

            $preset = _wp_array_get( $data, $path, null );
            if ( ! isset( $preset ) ) {
                continue;
            }

            $slugs_for_preset = array();
            foreach ( $preset as $item ) {
                if ( isset( $item['slug'] ) ) {
                    $slugs_for_preset[] = $item['slug'];
                }
            }

            _wp_array_set( $slugs, $metadata['path'], $slugs_for_preset );
        }

        return $slugs;
    }

    /**
     * Gets a `default`'s preset name by a provided slug.
     *
     * @since 5.9.0
     *
     * @param string $slug The slug we want to find a match from default presets.
     * @param array  $base_path The path to inspect. It's 'settings' by default.
     * @return string|null
     */
    protected function get_name_from_defaults( $slug, $base_path ) {
        $path            = $base_path;
        $path[]          = 'default';
        $default_content = _wp_array_get( $this->theme_json, $path, null );
        if ( ! $default_content ) {
            return null;
        }
        foreach ( $default_content as $item ) {
            if ( $slug === $item['slug'] ) {
                return $item['name'];
            }
        }
        return null;
    }

    /**
     * Removes the preset values whose slug is equal to any of given slugs.
     *
     * @since 5.9.0
     *
     * @param array $node  The node with the presets to validate.
     * @param array $slugs The slugs that should not be overridden.
     * @return array The new node.
     */
    protected static function filter_slugs( $node, $slugs ) {
        if ( empty( $slugs ) ) {
            return $node;
        }

        $new_node = array();
        foreach ( $node as $value ) {
            if ( isset( $value['slug'] ) && ! in_array( $value['slug'], $slugs, true ) ) {
                $new_node[] = $value;
            }
        }

        return $new_node;
    }

    /**
     * Removes insecure data from theme.json.
     *
     * @since 5.9.0
     * @since 6.3.2 Preserves global styles block variations when securing styles.
     *
     * @param array $theme_json Structure to sanitize.
     * @return array Sanitized structure.
     */
    public static function remove_insecure_properties( $theme_json ) {
        $sanitized = array();

        $theme_json = WP_Theme_JSON_Schema::migrate( $theme_json );

        $valid_block_names   = array_keys( static::get_blocks_metadata() );
        $valid_element_names = array_keys( static::ELEMENTS );
        $valid_variations    = static::get_valid_block_style_variations();

        $theme_json = static::sanitize( $theme_json, $valid_block_names, $valid_element_names, $valid_variations );

        $blocks_metadata = static::get_blocks_metadata();
        $style_nodes     = static::get_style_nodes( $theme_json, $blocks_metadata );

        foreach ( $style_nodes as $metadata ) {
            $input = _wp_array_get( $theme_json, $metadata['path'], array() );
            if ( empty( $input ) ) {
                continue;
            }

            // The global styles custom CSS is not sanitized, but can only be edited by users with 'edit_css' capability.
            if ( isset( $input['css'] ) && current_user_can( 'edit_css' ) ) {
                $output = $input;
            } else {
                $output = static::remove_insecure_styles( $input );
            }

            /*
             * Get a reference to element name from path.
             * $metadata['path'] = array( 'styles', 'elements', 'link' );
             */
            $current_element = $metadata['path'][ count( $metadata['path'] ) - 1 ];

            /*
             * $output is stripped of pseudo selectors. Re-add and process them
             * or insecure styles here.
             */
            if ( isset( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $current_element ] ) ) {
                foreach ( static::VALID_ELEMENT_PSEUDO_SELECTORS[ $current_element ] as $pseudo_selector ) {
                    if ( isset( $input[ $pseudo_selector ] ) ) {
                        $output[ $pseudo_selector ] = static::remove_insecure_styles( $input[ $pseudo_selector ] );
                    }
                }
            }

            if ( ! empty( $output ) ) {
                _wp_array_set( $sanitized, $metadata['path'], $output );
            }

            if ( isset( $metadata['variations'] ) ) {
                foreach ( $metadata['variations'] as $variation ) {
                    $variation_input = _wp_array_get( $theme_json, $variation['path'], array() );
                    if ( empty( $variation_input ) ) {
                        continue;
                    }

                    $variation_output = static::remove_insecure_styles( $variation_input );
                    if ( ! empty( $variation_output ) ) {
                        _wp_array_set( $sanitized, $variation['path'], $variation_output );
                    }
                }
            }
        }

        $setting_nodes = static::get_setting_nodes( $theme_json );
        foreach ( $setting_nodes as $metadata ) {
            $input = _wp_array_get( $theme_json, $metadata['path'], array() );
            if ( empty( $input ) ) {
                continue;
            }

            $output = static::remove_insecure_settings( $input );
            if ( ! empty( $output ) ) {
                _wp_array_set( $sanitized, $metadata['path'], $output );
            }
        }

        if ( empty( $sanitized['styles'] ) ) {
            unset( $theme_json['styles'] );
        } else {
            $theme_json['styles'] = $sanitized['styles'];
        }

        if ( empty( $sanitized['settings'] ) ) {
            unset( $theme_json['settings'] );
        } else {
            $theme_json['settings'] = $sanitized['settings'];
        }

        return $theme_json;
    }

    /**
     * Processes a setting node and returns the same node
     * without the insecure settings.
     *
     * @since 5.9.0
     *
     * @param array $input Node to process.
     * @return array
     */
    protected static function remove_insecure_settings( $input ) {
        $output = array();
        foreach ( static::PRESETS_METADATA as $preset_metadata ) {
            foreach ( static::VALID_ORIGINS as $origin ) {
                $path_with_origin   = $preset_metadata['path'];
                $path_with_origin[] = $origin;
                $presets            = _wp_array_get( $input, $path_with_origin, null );
                if ( null === $presets ) {
                    continue;
                }

                $escaped_preset = array();
                foreach ( $presets as $preset ) {
                    if (
                        esc_attr( esc_html( $preset['name'] ) ) === $preset['name'] &&
                        sanitize_html_class( $preset['slug'] ) === $preset['slug']
                    ) {
                        $value = null;
                        if ( isset( $preset_metadata['value_key'], $preset[ $preset_metadata['value_key'] ] ) ) {
                            $value = $preset[ $preset_metadata['value_key'] ];
                        } elseif (
                            isset( $preset_metadata['value_func'] ) &&
                            is_callable( $preset_metadata['value_func'] )
                        ) {
                            $value = call_user_func( $preset_metadata['value_func'], $preset );
                        }

                        $preset_is_valid = true;
                        foreach ( $preset_metadata['properties'] as $property ) {
                            if ( ! static::is_safe_css_declaration( $property, $value ) ) {
                                $preset_is_valid = false;
                                break;
                            }
                        }

                        if ( $preset_is_valid ) {
                            $escaped_preset[] = $preset;
                        }
                    }
                }

                if ( ! empty( $escaped_preset ) ) {
                    _wp_array_set( $output, $path_with_origin, $escaped_preset );
                }
            }
        }

        // Ensure indirect properties not included in any `PRESETS_METADATA` value are allowed.
        static::remove_indirect_properties( $input, $output );

        return $output;
    }

    /**
     * Processes a style node and returns the same node
     * without the insecure styles.
     *
     * @since 5.9.0
     *
     * @param array $input Node to process.
     * @return array
     */
    protected static function remove_insecure_styles( $input ) {
        $output       = array();
        $declarations = static::compute_style_properties( $input );

        foreach ( $declarations as $declaration ) {
            if ( static::is_safe_css_declaration( $declaration['name'], $declaration['value'] ) ) {
                $path = static::PROPERTIES_METADATA[ $declaration['name'] ];

                /*
                 * Check the value isn't an array before adding so as to not
                 * double up shorthand and longhand styles.
                 */
                $value = _wp_array_get( $input, $path, array() );
                if ( ! is_array( $value ) ) {
                    _wp_array_set( $output, $path, $value );
                }
            }
        }

        // Ensure indirect properties not handled by `compute_style_properties` are allowed.
        static::remove_indirect_properties( $input, $output );

        return $output;
    }

    /**
     * Checks that a declaration provided by the user is safe.
     *
     * @since 5.9.0
     *
     * @param string $property_name  Property name in a CSS declaration, i.e. the `color` in `color: red`.
     * @param string $property_value Value in a CSS declaration, i.e. the `red` in `color: red`.
     * @return bool
     */
    protected static function is_safe_css_declaration( $property_name, $property_value ) {
        $style_to_validate = $property_name . ': ' . $property_value;
        $filtered          = esc_html( safecss_filter_attr( $style_to_validate ) );
        return ! empty( trim( $filtered ) );
    }

    /**
     * Removes indirect properties from the given input node and
     * sets in the given output node.
     *
     * @since 6.2.0
     *
     * @param array $input  Node to process.
     * @param array $output The processed node. Passed by reference.
     */
    private static function remove_indirect_properties( $input, &$output ) {
        foreach ( static::INDIRECT_PROPERTIES_METADATA as $property => $paths ) {
            foreach ( $paths as $path ) {
                $value = _wp_array_get( $input, $path );
                if (
                    is_string( $value ) &&
                    static::is_safe_css_declaration( $property, $value )
                ) {
                    _wp_array_set( $output, $path, $value );
                }
            }
        }
    }

    /**
     * Returns the raw data.
     *
     * @since 5.8.0
     *
     * @return array Raw data.
     */
    public function get_raw_data() {
        return $this->theme_json;
    }

    /**
     * Transforms the given editor settings according the
     * add_theme_support format to the theme.json format.
     *
     * @since 5.8.0
     *
     * @param array $settings Existing editor settings.
     * @return array Config that adheres to the theme.json schema.
     */
    public static function get_from_editor_settings( $settings ) {
        $theme_settings = array(
            'version'  => static::LATEST_SCHEMA,
            'settings' => array(),
        );

        // Deprecated theme supports.
        if ( isset( $settings['disableCustomColors'] ) ) {
            if ( ! isset( $theme_settings['settings']['color'] ) ) {
                $theme_settings['settings']['color'] = array();
            }
            $theme_settings['settings']['color']['custom'] = ! $settings['disableCustomColors'];
        }

        if ( isset( $settings['disableCustomGradients'] ) ) {
            if ( ! isset( $theme_settings['settings']['color'] ) ) {
                $theme_settings['settings']['color'] = array();
            }
            $theme_settings['settings']['color']['customGradient'] = ! $settings['disableCustomGradients'];
        }

        if ( isset( $settings['disableCustomFontSizes'] ) ) {
            if ( ! isset( $theme_settings['settings']['typography'] ) ) {
                $theme_settings['settings']['typography'] = array();
            }
            $theme_settings['settings']['typography']['customFontSize'] = ! $settings['disableCustomFontSizes'];
        }

        if ( isset( $settings['enableCustomLineHeight'] ) ) {
            if ( ! isset( $theme_settings['settings']['typography'] ) ) {
                $theme_settings['settings']['typography'] = array();
            }
            $theme_settings['settings']['typography']['lineHeight'] = $settings['enableCustomLineHeight'];
        }

        if ( isset( $settings['enableCustomUnits'] ) ) {
            if ( ! isset( $theme_settings['settings']['spacing'] ) ) {
                $theme_settings['settings']['spacing'] = array();
            }
            $theme_settings['settings']['spacing']['units'] = ( true === $settings['enableCustomUnits'] ) ?
                array( 'px', 'em', 'rem', 'vh', 'vw', '%' ) :
                $settings['enableCustomUnits'];
        }

        if ( isset( $settings['colors'] ) ) {
            if ( ! isset( $theme_settings['settings']['color'] ) ) {
                $theme_settings['settings']['color'] = array();
            }
            $theme_settings['settings']['color']['palette'] = $settings['colors'];
        }

        if ( isset( $settings['gradients'] ) ) {
            if ( ! isset( $theme_settings['settings']['color'] ) ) {
                $theme_settings['settings']['color'] = array();
            }
            $theme_settings['settings']['color']['gradients'] = $settings['gradients'];
        }

        if ( isset( $settings['fontSizes'] ) ) {
            $font_sizes = $settings['fontSizes'];
            // Back-compatibility for presets without units.
            foreach ( $font_sizes as $key => $font_size ) {
                if ( is_numeric( $font_size['size'] ) ) {
                    $font_sizes[ $key ]['size'] = $font_size['size'] . 'px';
                }
            }
            if ( ! isset( $theme_settings['settings']['typography'] ) ) {
                $theme_settings['settings']['typography'] = array();
            }
            $theme_settings['settings']['typography']['fontSizes'] = $font_sizes;
        }

        if ( isset( $settings['enableCustomSpacing'] ) ) {
            if ( ! isset( $theme_settings['settings']['spacing'] ) ) {
                $theme_settings['settings']['spacing'] = array();
            }
            $theme_settings['settings']['spacing']['padding'] = $settings['enableCustomSpacing'];
        }

        return $theme_settings;
    }

    /**
     * Returns the current theme's wanted patterns(slugs) to be
     * registered from Pattern Directory.
     *
     * @since 6.0.0
     *
     * @return string[]
     */
    public function get_patterns() {
        if ( isset( $this->theme_json['patterns'] ) && is_array( $this->theme_json['patterns'] ) ) {
            return $this->theme_json['patterns'];
        }
        return array();
    }

    /**
     * Returns a valid theme.json as provided by a theme.
     *
     * Unlike get_raw_data() this returns the presets flattened, as provided by a theme.
     * This also uses appearanceTools instead of their opt-ins if all of them are true.
     *
     * @since 6.0.0
     *
     * @return array
     */
    public function get_data() {
        $output = $this->theme_json;
        $nodes  = static::get_setting_nodes( $output );

        /**
         * Flatten the theme & custom origins into a single one.
         *
         * For example, the following:
         *
         * {
         *   "settings": {
         *     "color": {
         *       "palette": {
         *         "theme": [ {} ],
         *         "custom": [ {} ]
         *       }
         *     }
         *   }
         * }
         *
         * will be converted to:
         *
         * {
         *   "settings": {
         *     "color": {
         *       "palette": [ {} ]
         *     }
         *   }
         * }
         */
        foreach ( $nodes as $node ) {
            foreach ( static::PRESETS_METADATA as $preset_metadata ) {
                $path = $node['path'];
                foreach ( $preset_metadata['path'] as $preset_metadata_path ) {
                    $path[] = $preset_metadata_path;
                }
                $preset = _wp_array_get( $output, $path, null );
                if ( null === $preset ) {
                    continue;
                }

                $items = array();
                if ( isset( $preset['theme'] ) ) {
                    foreach ( $preset['theme'] as $item ) {
                        $slug = $item['slug'];
                        unset( $item['slug'] );
                        $items[ $slug ] = $item;
                    }
                }
                if ( isset( $preset['custom'] ) ) {
                    foreach ( $preset['custom'] as $item ) {
                        $slug = $item['slug'];
                        unset( $item['slug'] );
                        $items[ $slug ] = $item;
                    }
                }
                $flattened_preset = array();
                foreach ( $items as $slug => $value ) {
                    $flattened_preset[] = array_merge( array( 'slug' => (string) $slug ), $value );
                }
                _wp_array_set( $output, $path, $flattened_preset );
            }
        }

        /*
         * If all of the static::APPEARANCE_TOOLS_OPT_INS are true,
         * this code unsets them and sets 'appearanceTools' instead.
         */
        foreach ( $nodes as $node ) {
            $all_opt_ins_are_set = true;
            foreach ( static::APPEARANCE_TOOLS_OPT_INS as $opt_in_path ) {
                $full_path = $node['path'];
                foreach ( $opt_in_path as $opt_in_path_item ) {
                    $full_path[] = $opt_in_path_item;
                }
                /*
                 * Use "unset prop" as a marker instead of "null" because
                 * "null" can be a valid value for some props (e.g. blockGap).
                 */
                $opt_in_value = _wp_array_get( $output, $full_path, 'unset prop' );
                if ( 'unset prop' === $opt_in_value ) {
                    $all_opt_ins_are_set = false;
                    break;
                }
            }

            if ( $all_opt_ins_are_set ) {
                $node_path_with_appearance_tools   = $node['path'];
                $node_path_with_appearance_tools[] = 'appearanceTools';
                _wp_array_set( $output, $node_path_with_appearance_tools, true );
                foreach ( static::APPEARANCE_TOOLS_OPT_INS as $opt_in_path ) {
                    $full_path = $node['path'];
                    foreach ( $opt_in_path as $opt_in_path_item ) {
                        $full_path[] = $opt_in_path_item;
                    }
                    /*
                     * Use "unset prop" as a marker instead of "null" because
                     * "null" can be a valid value for some props (e.g. blockGap).
                     */
                    $opt_in_value = _wp_array_get( $output, $full_path, 'unset prop' );
                    if ( true !== $opt_in_value ) {
                        continue;
                    }

                    /*
                     * The following could be improved to be path independent.
                     * At the moment it relies on a couple of assumptions:
                     *
                     * - all opt-ins having a path of size 2.
                     * - there's two sources of settings: the top-level and the block-level.
                     */
                    if (
                        ( 1 === count( $node['path'] ) ) &&
                        ( 'settings' === $node['path'][0] )
                    ) {
                        // Top-level settings.
                        unset( $output['settings'][ $opt_in_path[0] ][ $opt_in_path[1] ] );
                        if ( empty( $output['settings'][ $opt_in_path[0] ] ) ) {
                            unset( $output['settings'][ $opt_in_path[0] ] );
                        }
                    } elseif (
                        ( 3 === count( $node['path'] ) ) &&
                        ( 'settings' === $node['path'][0] ) &&
                        ( 'blocks' === $node['path'][1] )
                    ) {
                        // Block-level settings.
                        $block_name = $node['path'][2];
                        unset( $output['settings']['blocks'][ $block_name ][ $opt_in_path[0] ][ $opt_in_path[1] ] );
                        if ( empty( $output['settings']['blocks'][ $block_name ][ $opt_in_path[0] ] ) ) {
                            unset( $output['settings']['blocks'][ $block_name ][ $opt_in_path[0] ] );
                        }
                    }
                }
            }
        }

        wp_recursive_ksort( $output );

        return $output;
    }

    /**
     * Sets the spacingSizes array based on the spacingScale values from theme.json.
     *
     * @since 6.1.0
     *
     * @return null|void
     */
    public function set_spacing_sizes() {
        $spacing_scale = isset( $this->theme_json['settings']['spacing']['spacingScale'] )
            ? $this->theme_json['settings']['spacing']['spacingScale']
            : array();

        if ( ! isset( $spacing_scale['steps'] )
            || ! is_numeric( $spacing_scale['steps'] )
            || ! isset( $spacing_scale['mediumStep'] )
            || ! isset( $spacing_scale['unit'] )
            || ! isset( $spacing_scale['operator'] )
            || ! isset( $spacing_scale['increment'] )
            || ! isset( $spacing_scale['steps'] )
            || ! is_numeric( $spacing_scale['increment'] )
            || ! is_numeric( $spacing_scale['mediumStep'] )
            || ( '+' !== $spacing_scale['operator'] && '*' !== $spacing_scale['operator'] ) ) {
            if ( ! empty( $spacing_scale ) ) {
                trigger_error(
                    sprintf(
                        /* translators: 1: theme.json, 2: settings.spacing.spacingScale */
                        __( 'Some of the %1$s %2$s values are invalid' ),
                        'theme.json',
                        'settings.spacing.spacingScale'
                    ),
                    E_USER_NOTICE
                );
            }
            return null;
        }

        // If theme authors want to prevent the generation of the core spacing scale they can set their theme.json spacingScale.steps to 0.
        if ( 0 === $spacing_scale['steps'] ) {
            return null;
        }

        $unit            = '%' === $spacing_scale['unit'] ? '%' : sanitize_title( $spacing_scale['unit'] );
        $current_step    = $spacing_scale['mediumStep'];
        $steps_mid_point = round( $spacing_scale['steps'] / 2, 0 );
        $x_small_count   = null;
        $below_sizes     = array();
        $slug            = 40;
        $remainder       = 0;

        for ( $below_midpoint_count = $steps_mid_point - 1; $spacing_scale['steps'] > 1 && $slug > 0 && $below_midpoint_count > 0; $below_midpoint_count-- ) {
            if ( '+' === $spacing_scale['operator'] ) {
                $current_step -= $spacing_scale['increment'];
            } elseif ( $spacing_scale['increment'] > 1 ) {
                $current_step /= $spacing_scale['increment'];
            } else {
                $current_step *= $spacing_scale['increment'];
            }

            if ( $current_step <= 0 ) {
                $remainder = $below_midpoint_count;
                break;
            }

            $below_sizes[] = array(
                /* translators: %s: Digit to indicate multiple of sizing, eg. 2X-Small. */
                'name' => $below_midpoint_count === $steps_mid_point - 1 ? __( 'Small' ) : sprintf( __( '%sX-Small' ), (string) $x_small_count ),
                'slug' => (string) $slug,
                'size' => round( $current_step, 2 ) . $unit,
            );

            if ( $below_midpoint_count === $steps_mid_point - 2 ) {
                $x_small_count = 2;
            }

            if ( $below_midpoint_count < $steps_mid_point - 2 ) {
                ++$x_small_count;
            }

            $slug -= 10;
        }

        $below_sizes = array_reverse( $below_sizes );

        $below_sizes[] = array(
            'name' => __( 'Medium' ),
            'slug' => '50',
            'size' => $spacing_scale['mediumStep'] . $unit,
        );

        $current_step  = $spacing_scale['mediumStep'];
        $x_large_count = null;
        $above_sizes   = array();
        $slug          = 60;
        $steps_above   = ( $spacing_scale['steps'] - $steps_mid_point ) + $remainder;

        for ( $above_midpoint_count = 0; $above_midpoint_count < $steps_above; $above_midpoint_count++ ) {
            $current_step = '+' === $spacing_scale['operator']
                ? $current_step + $spacing_scale['increment']
                : ( $spacing_scale['increment'] >= 1 ? $current_step * $spacing_scale['increment'] : $current_step / $spacing_scale['increment'] );

            $above_sizes[] = array(
                /* translators: %s: Digit to indicate multiple of sizing, eg. 2X-Large. */
                'name' => 0 === $above_midpoint_count ? __( 'Large' ) : sprintf( __( '%sX-Large' ), (string) $x_large_count ),
                'slug' => (string) $slug,
                'size' => round( $current_step, 2 ) . $unit,
            );

            if ( 1 === $above_midpoint_count ) {
                $x_large_count = 2;
            }

            if ( $above_midpoint_count > 1 ) {
                ++$x_large_count;
            }

            $slug += 10;
        }

        $spacing_sizes = $below_sizes;
        foreach ( $above_sizes as $above_sizes_item ) {
            $spacing_sizes[] = $above_sizes_item;
        }

        // If there are 7 or fewer steps in the scale revert to numbers for labels instead of t-shirt sizes.
        if ( $spacing_scale['steps'] <= 7 ) {
            for ( $spacing_sizes_count = 0; $spacing_sizes_count < count( $spacing_sizes ); $spacing_sizes_count++ ) {
                $spacing_sizes[ $spacing_sizes_count ]['name'] = (string) ( $spacing_sizes_count + 1 );
            }
        }

        _wp_array_set( $this->theme_json, array( 'settings', 'spacing', 'spacingSizes', 'default' ), $spacing_sizes );
    }

    /**
     * This is used to convert the internal representation of variables to the CSS representation.
     * For example, `var:preset|color|vivid-green-cyan` becomes `var(--wp--preset--color--vivid-green-cyan)`.
     *
     * @since 6.3.0
     * @param string $value The variable such as var:preset|color|vivid-green-cyan to convert.
     * @return string The converted variable.
     */
    private static function convert_custom_properties( $value ) {
        $prefix     = 'var:';
        $prefix_len = strlen( $prefix );
        $token_in   = '|';
        $token_out  = '--';
        if ( str_starts_with( $value, $prefix ) ) {
            $unwrapped_name = str_replace(
                $token_in,
                $token_out,
                substr( $value, $prefix_len )
            );
            $value          = "var(--wp--$unwrapped_name)";
        }

        return $value;
    }

    /**
     * Given a tree, converts the internal representation of variables to the CSS representation.
     * It is recursive and modifies the input in-place.
     *
     * @since 6.3.0
     * @param array $tree   Input to process.
     * @return array The modified $tree.
     */
    private static function resolve_custom_css_format( $tree ) {
        $prefix = 'var:';

        foreach ( $tree as $key => $data ) {
            if ( is_string( $data ) && str_starts_with( $data, $prefix ) ) {
                $tree[ $key ] = self::convert_custom_properties( $data );
            } elseif ( is_array( $data ) ) {
                $tree[ $key ] = self::resolve_custom_css_format( $data );
            }
        }

        return $tree;
    }

    /**
     * Returns the selectors metadata for a block.
     *
     * @since 6.3.0
     *
     * @param object $block_type    The block type.
     * @param string $root_selector The block's root selector.
     *
     * @return array The custom selectors set by the block.
     */
    protected static function get_block_selectors( $block_type, $root_selector ) {
        if ( ! empty( $block_type->selectors ) ) {
            return $block_type->selectors;
        }

        $selectors = array( 'root' => $root_selector );
        foreach ( static::BLOCK_SUPPORT_FEATURE_LEVEL_SELECTORS as $key => $feature ) {
            $feature_selector = wp_get_block_css_selector( $block_type, $key );
            if ( null !== $feature_selector ) {
                $selectors[ $feature ] = array( 'root' => $feature_selector );
            }
        }

        return $selectors;
    }

    /**
     * Generates all the element selectors for a block.
     *
     * @since 6.3.0
     *
     * @param string $root_selector The block's root CSS selector.
     * @return array The block's element selectors.
     */
    protected static function get_block_element_selectors( $root_selector ) {
        /*
         * Assign defaults, then override those that the block sets by itself.
         * If the block selector is compounded, will append the element to each
         * individual block selector.
         */
        $block_selectors   = explode( ',', $root_selector );
        $element_selectors = array();
        foreach ( static::ELEMENTS as $el_name => $el_selector ) {
            $element_selector = array();
            foreach ( $block_selectors as $selector ) {
                if ( $selector === $el_selector ) {
                    $element_selector = array( $el_selector );
                    break;
                }
                $element_selector[] = static::prepend_to_selector( $el_selector, $selector . ' ' );
            }
            $element_selectors[ $el_name ] = implode( ',', $element_selector );
        }

        return $element_selectors;
    }

    /**
     * Generates style declarations for a node's features e.g., color, border,
     * typography etc. that have custom selectors in their related block's
     * metadata.
     *
     * @since 6.3.0
     *
     * @param object $metadata The related block metadata containing selectors.
     * @param object $node     A merged theme.json node for block or variation.
     *
     * @return array The style declarations for the node's features with custom
     * selectors.
     */
    protected function get_feature_declarations_for_node( $metadata, &$node ) {
        $declarations = array();

        if ( ! isset( $metadata['selectors'] ) ) {
            return $declarations;
        }

        $settings = isset( $this->theme_json['settings'] )
            ? $this->theme_json['settings']
            : array();

        foreach ( $metadata['selectors'] as $feature => $feature_selectors ) {
            /*
             * Skip if this is the block's root selector or the block doesn't
             * have any styles for the feature.
             */
            if ( 'root' === $feature || empty( $node[ $feature ] ) ) {
                continue;
            }

            if ( is_array( $feature_selectors ) ) {
                foreach ( $feature_selectors as $subfeature => $subfeature_selector ) {
                    if ( 'root' === $subfeature || empty( $node[ $feature ][ $subfeature ] ) ) {
                        continue;
                    }

                    /*
                     * Create temporary node containing only the subfeature data
                     * to leverage existing `compute_style_properties` function.
                     */
                    $subfeature_node = array(
                        $feature => array(
                            $subfeature => $node[ $feature ][ $subfeature ],
                        ),
                    );

                    // Generate style declarations.
                    $new_declarations = static::compute_style_properties( $subfeature_node, $settings, null, $this->theme_json );

                    // Merge subfeature declarations into feature declarations.
                    if ( isset( $declarations[ $subfeature_selector ] ) ) {
                        foreach ( $new_declarations as $new_declaration ) {
                            $declarations[ $subfeature_selector ][] = $new_declaration;
                        }
                    } else {
                        $declarations[ $subfeature_selector ] = $new_declarations;
                    }

                    /*
                     * Remove the subfeature from the block's node now its
                     * styles will be included under its own selector not the
                     * block's.
                     */
                    unset( $node[ $feature ][ $subfeature ] );
                }
            }

            /*
             * Now subfeatures have been processed and removed we can process
             * feature root selector or simple string selector.
             */
            if (
                is_string( $feature_selectors ) ||
                ( isset( $feature_selectors['root'] ) && $feature_selectors['root'] )
            ) {
                $feature_selector = is_string( $feature_selectors ) ? $feature_selectors : $feature_selectors['root'];

                /*
                 * Create temporary node containing only the feature data
                 * to leverage existing `compute_style_properties` function.
                 */
                $feature_node = array( $feature => $node[ $feature ] );

                // Generate the style declarations.
                $new_declarations = static::compute_style_properties( $feature_node, $settings, null, $this->theme_json );

                /*
                 * Merge new declarations with any that already exist for
                 * the feature selector. This may occur when multiple block
                 * support features use the same custom selector.
                 */
                if ( isset( $declarations[ $feature_selector ] ) ) {
                    foreach ( $new_declarations as $new_declaration ) {
                        $declarations[ $feature_selector ][] = $new_declaration;
                    }
                } else {
                    $declarations[ $feature_selector ] = $new_declarations;
                }

                /*
                 * Remove the feature from the block's node now its styles
                 * will be included under its own selector not the block's.
                 */
                unset( $node[ $feature ] );
            }
        }

        return $declarations;
    }

    /**
     * Replaces CSS variables with their values in place.
     *
     * @since 6.3.0
     * @since 6.5.0 Check for empty style before processing its value.
     *
     * @param array $styles CSS declarations to convert.
     * @param array $values key => value pairs to use for replacement.
     * @return array
     */
    private static function convert_variables_to_value( $styles, $values ) {
        foreach ( $styles as $key => $style ) {
            if ( empty( $style ) ) {
                continue;
            }

            if ( is_array( $style ) ) {
                $styles[ $key ] = self::convert_variables_to_value( $style, $values );
                continue;
            }

            if ( 0 <= strpos( $style, 'var(' ) ) {
                // find all the variables in the string in the form of var(--variable-name, fallback), with fallback in the second capture group.

                $has_matches = preg_match_all( '/var\(([^),]+)?,?\s?(\S+)?\)/', $style, $var_parts );

                if ( $has_matches ) {
                    $resolved_style = $styles[ $key ];
                    foreach ( $var_parts[1] as $index => $var_part ) {
                        $key_in_values   = 'var(' . $var_part . ')';
                        $rule_to_replace = $var_parts[0][ $index ]; // the css rule to replace e.g. var(--wp--preset--color--vivid-green-cyan).
                        $fallback        = $var_parts[2][ $index ]; // the fallback value.
                        $resolved_style  = str_replace(
                            array(
                                $rule_to_replace,
                                $fallback,
                            ),
                            array(
                                isset( $values[ $key_in_values ] ) ? $values[ $key_in_values ] : $rule_to_replace,
                                isset( $values[ $fallback ] ) ? $values[ $fallback ] : $fallback,
                            ),
                            $resolved_style
                        );
                    }
                    $styles[ $key ] = $resolved_style;
                }
            }
        }

        return $styles;
    }

    /**
     * Resolves the values of CSS variables in the given styles.
     *
     * @since 6.3.0
     * @param WP_Theme_JSON $theme_json The theme json resolver.
     *
     * @return WP_Theme_JSON The $theme_json with resolved variables.
     */
    public static function resolve_variables( $theme_json ) {
        $settings    = $theme_json->get_settings();
        $styles      = $theme_json->get_raw_data()['styles'];
        $preset_vars = static::compute_preset_vars( $settings, static::VALID_ORIGINS );
        $theme_vars  = static::compute_theme_vars( $settings );
        $vars        = array_reduce(
            array_merge( $preset_vars, $theme_vars ),
            function ( $carry, $item ) {
                $name                    = $item['name'];
                $carry[ "var({$name})" ] = $item['value'];
                return $carry;
            },
            array()
        );

        $theme_json->theme_json['styles'] = self::convert_variables_to_value( $styles, $vars );
        return $theme_json;
    }

    /**
     * Generates a selector for a block style variation.
     *
     * @since 6.5.0
     *
     * @param string $variation_name Name of the block style variation.
     * @param string $block_selector CSS selector for the block.
     * @return string Block selector with block style variation selector added to it.
     */
    protected static function get_block_style_variation_selector( $variation_name, $block_selector ) {
        $variation_class = ".is-style-$variation_name";

        if ( ! $block_selector ) {
            return $variation_class;
        }

        $limit          = 1;
        $selector_parts = explode( ',', $block_selector );
        $result         = array();

        foreach ( $selector_parts as $part ) {
            $result[] = preg_replace_callback(
                '/((?::\([^)]+\))?\s*)([^\s:]+)/',
                function ( $matches ) use ( $variation_class ) {
                    return $matches[1] . $matches[2] . $variation_class;
                },
                $part,
                $limit
            );
        }

        return implode( ',', $result );
    }

    /**
     * Collects valid block style variations keyed by block type.
     *
     * @since 6.6.0
     *
     * @return array Valid block style variations by block type.
     */
    protected static function get_valid_block_style_variations() {
        $valid_variations = array();
        foreach ( self::get_blocks_metadata() as $block_name => $block_meta ) {
            if ( ! isset( $block_meta['styleVariations'] ) ) {
                continue;
            }
            $valid_variations[ $block_name ] = array_keys( $block_meta['styleVariations'] );
        }

        return $valid_variations;
    }
}