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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-$slug-border-color'     => 'border-color',
	 *                       )
	 * - properties       => array of CSS properties to be used by kses to
	 *                       validate the content of each preset
	 *                       by means of the remove_insecure_properties method.
	 *
	 * @since 5.8.0
	 * @since 5.9.0 Added the `color.duotone` and `typography.fontFamilies` presets,
	 *              `use_default_names` preset key, and simplified the metadata structure.
	 * @since 6.0.0 Replaced `override` with `prevent_override` and updated the
	 *              `prevent_override` value for `color.duotone` to use `color.defaultDuotone`.
	 * @since 6.2.0 Added 'shadow' presets.
	 * @since 6.3.0 Replaced value_func for duotone with `null`. Custom properties are handled by class-wp-duotone.php.
	 * @since 6.6.0 Added the `dimensions.aspectRatios` and `dimensions.defaultAspectRatios` presets.
	 *              Updated the 'prevent_override' value for font size presets to use 'typography.defaultFontSizes'
	 *              and spacing size presets to use `spacing.defaultSpacingSizes`.
	 * @var array
	 */
	const PRESETS_METADATA = array(
		array(
			'path'              => array( 'dimensions', 'aspectRatios' ),
			'prevent_override'  => array( 'dimensions', 'defaultAspectRatios' ),
			'use_default_names' => false,
			'value_key'         => 'ratio',
			'css_vars'          => '--wp--preset--aspect-ratio--$slug',
			'classes'           => array(),
			'properties'        => array( 'aspect-ratio' ),
		),
		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'  => array( 'typography', 'defaultFontSizes' ),
			'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'  => array( 'spacing', 'defaultSpacingSizes' ),
			'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.
	 * @since 6.7.0 Added `background-attachment` property.
	 *
	 * @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' ),
		'background-attachment'             => array( 'background', 'backgroundAttachment' ),
		'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' ),
		'text-align'                        => array( 'typography', 'textAlign' ),
		'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.
	 * @since 6.6.0 Added `blockTypes` to support block style variation theme.json partials.
	 * @var string[]
	 */
	const VALID_TOP_LEVEL_KEYS = array(
		'blockTypes',
		'customTemplates',
		'description',
		'patterns',
		'settings',
		'slug',
		'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`.
	 * @since 6.6.0 Added support for 'dimensions.aspectRatios', 'dimensions.defaultAspectRatios',
	 *              'typography.defaultFontSizes', and 'spacing.defaultSpacingSizes'.
	 * @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,
			'aspectRatios'        => null,
			'defaultAspectRatios' => 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,
			'defaultSpacingSizes' => 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,
			'defaultFontSizes' => null,
			'dropCap'          => null,
			'fontFamilies'     => null,
			'fontSizes'        => null,
			'fontStyle'        => null,
			'fontWeight'       => null,
			'letterSpacing'    => null,
			'lineHeight'       => null,
			'textAlign'        => 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'      => null,
			'backgroundPosition'   => null,
			'backgroundRepeat'     => null,
			'backgroundSize'       => null,
			'backgroundAttachment' => null,
		),
		'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,
			'textAlign'      => 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.
	 * @since 6.6.0 Changed value from 2 to 3.
	 * @var int
	 */
	const LATEST_SCHEMA = 3;

	/**
	 * Constructor.
	 *
	 * @since 5.8.0
	 * @since 6.6.0 Key spacingScale by origin, and Pre-generate the spacingSizes from spacingScale.
	 *              Added unwrapping of shared block style variations into block type variations if registered.
	 *
	 * @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 'blocks', 'default', 'theme', or 'custom'. Default 'theme'.
	 */
	public function __construct( $theme_json = array( 'version' => self::LATEST_SCHEMA ), $origin = 'theme' ) {
		if ( ! in_array( $origin, static::VALID_ORIGINS, true ) ) {
			$origin = 'theme';
		}

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

		// In addition to presets, spacingScale (which generates presets) is also keyed by origin.
		$scale_path    = array( 'settings', 'spacing', 'spacingScale' );
		$spacing_scale = _wp_array_get( $this->theme_json, $scale_path, null );
		if ( null !== $spacing_scale ) {
			// If the spacingScale is not already keyed by origin.
			if ( empty( array_intersect( array_keys( $spacing_scale ), static::VALID_ORIGINS ) ) ) {
				_wp_array_set( $this->theme_json, $scale_path, array( $origin => $spacing_scale ) );
			}
		}

		// Pre-generate the spacingSizes from spacingScale.
		$scale_path    = array( 'settings', 'spacing', 'spacingScale', $origin );
		$spacing_scale = _wp_array_get( $this->theme_json, $scale_path, null );
		if ( isset( $spacing_scale ) ) {
			$sizes_path           = array( 'settings', 'spacing', 'spacingSizes', $origin );
			$spacing_sizes        = _wp_array_get( $this->theme_json, $sizes_path, array() );
			$spacing_scale_sizes  = static::compute_spacing_sizes( $spacing_scale );
			$merged_spacing_sizes = static::merge_spacing_sizes( $spacing_scale_sizes, $spacing_sizes );
			_wp_array_set( $this->theme_json, $sizes_path, $merged_spacing_sizes );
		}
	}

	/**
	 * Unwraps shared block style variations.
	 *
	 * It takes the shared variations (styles.variations.variationName) and
	 * applies them to all the blocks that have the given variation registered
	 * (styles.blocks.blockType.variations.variationName).
	 *
	 * For example, given the `core/paragraph` and `core/group` blocks have
	 * registered the `section-a` style variation, and given the following input:
	 *
	 * {
	 *   "styles": {
	 *     "variations": {
	 *       "section-a": { "color": { "background": "backgroundColor" } }
	 *     }
	 *   }
	 * }
	 *
	 * It returns the following output:
	 *
	 * {
	 *   "styles": {
	 *     "blocks": {
	 *       "core/paragraph": {
	 *         "variations": {
	 *             "section-a": { "color": { "background": "backgroundColor" } }
	 *         },
	 *       },
	 *       "core/group": {
	 *         "variations": {
	 *           "section-a": { "color": { "background": "backgroundColor" } }
	 *         }
	 *       }
	 *     }
	 *   }
	 * }
	 *
	 * @since 6.6.0
	 *
	 * @param array $theme_json       A structure that follows the theme.json schema.
	 * @param array $valid_variations Valid block style variations.
	 * @return array Theme json data with shared variation definitions unwrapped under appropriate block types.
	 */
	private static function unwrap_shared_block_style_variations( $theme_json, $valid_variations ) {
		if ( empty( $theme_json['styles']['variations'] ) || empty( $valid_variations ) ) {
			return $theme_json;
		}

		$new_theme_json = $theme_json;
		$variations     = $new_theme_json['styles']['variations'];

		foreach ( $valid_variations as $block_type => $registered_variations ) {
			foreach ( $registered_variations as $variation_name ) {
				$block_level_data = $new_theme_json['styles']['blocks'][ $block_type ]['variations'][ $variation_name ] ?? array();
				$top_level_data   = $variations[ $variation_name ] ?? array();
				$merged_data      = array_replace_recursive( $top_level_data, $block_level_data );
				if ( ! empty( $merged_data ) ) {
					_wp_array_set( $new_theme_json, array( 'styles', 'blocks', $block_type, 'variations', $variation_name ), $merged_data );
				}
			}
		}

		unset( $new_theme_json['styles']['variations'] );

		return $new_theme_json;
	}

	/**
	 * 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.
	 * @since 6.6.0 Updated schema to allow extended block style variations.
	 *
	 * @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();

		/*
		 * Generate a schema for blocks.
		 * - Block styles can contain `elements` & `variations` definitions.
		 * - Variations definitions cannot be nested.
		 * - Variations can contain styles for inner `blocks`.
		 * - Variation inner `blocks` styles can contain `elements`.
		 *
		 * As each variation needs a `blocks` schema but further nested
		 * inner `blocks`, the overall schema will be generated in multiple passes.
		 */
		foreach ( $valid_block_names as $block ) {
			$schema_settings_blocks[ $block ]           = static::VALID_SETTINGS;
			$schema_styles_blocks[ $block ]             = $styles_non_top_level;
			$schema_styles_blocks[ $block ]['elements'] = $schema_styles_elements;
		}

		$block_style_variation_styles             = static::VALID_STYLES;
		$block_style_variation_styles['blocks']   = $schema_styles_blocks;
		$block_style_variation_styles['elements'] = $schema_styles_elements;

		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, $block_style_variation_styles );
			}

			$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.
	 * @since 6.6.0 Updated to include block style variations from the block styles registry.
	 *
	 * @return array Block metadata.
	 */
	protected static function get_blocks_metadata() {
		$registry       = WP_Block_Type_Registry::get_instance();
		$blocks         = $registry->get_all_registered();
		$style_registry = WP_Block_Styles_Registry::get_instance();

		// Is there metadata for all currently registered blocks?
		$blocks = array_diff_key( $blocks, static::$blocks_metadata );
		if ( empty( $blocks ) ) {
			/*
			 * New block styles may have been registered within WP_Block_Styles_Registry.
			 * Update block metadata for any new block style variations.
			 */
			$registered_styles = $style_registry->get_all_registered();
			foreach ( static::$blocks_metadata as $block_name => $block_metadata ) {
				if ( ! empty( $registered_styles[ $block_name ] ) ) {
					$style_selectors = $block_metadata['styleVariations'] ?? array();

					foreach ( $registered_styles[ $block_name ] as $block_style ) {
						if ( ! isset( $style_selectors[ $block_style['name'] ] ) ) {
							$style_selectors[ $block_style['name'] ] = static::get_block_style_variation_selector( $block_style['name'], $block_metadata['selector'] );
						}
					}

					static::$blocks_metadata[ $block_name ]['styleVariations'] = $style_selectors;
				}
			}
			return static::$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.
			$style_selectors = array();
			if ( ! empty( $block_type->styles ) ) {
				foreach ( $block_type->styles as $style ) {
					$style_selectors[ $style['name'] ] = static::get_block_style_variation_selector( $style['name'], static::$blocks_metadata[ $block_name ]['selector'] );
				}
			}

			// Block style variations can be registered through the WP_Block_Styles_Registry as well as block.json.
			$registered_styles = $style_registry->get_registered_styles_for_block( $block_name );
			foreach ( $registered_styles as $style ) {
				$style_selectors[ $style['name'] ] = static::get_block_style_variation_selector( $style['name'], static::$blocks_metadata[ $block_name ]['selector'] );
			}

			if ( ! empty( $style_selectors ) ) {
				static::$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.
	 * @since 6.6.0 Added boolean `skip_root_layout_styles` and `include_block_style_variations` options
	 *              to control styles output as desired.
	 *
	 * @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 {
	 *     Optional. An array of options for now used for internal purposes only (may change without notice).
	 *
	 *     @type string $scope                           Makes sure all style are scoped to a given selector
	 *     @type string $root_selector                   Overwrites and forces a given selector to be used on the root node
	 *     @type bool   $skip_root_layout_styles         Omits root layout styles from the generated stylesheet. Default false.
	 *     @type bool   $include_block_style_variations  Includes styles for block style variations in the generated stylesheet. Default false.
	 * }
	 * @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, $options );
		$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 = static::scope_style_node_selectors( $options['scope'], $node );
			}
			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 && empty( $options['skip_root_layout_styles'] ) ) {
				$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 );
		}

		// Load the custom CSS last so it has the highest specificity.
		if ( in_array( 'custom-css', $types, true ) ) {
			// Add the global styles root CSS.
			$stylesheet .= _wp_array_get( $this->theme_json, array( 'styles', 'css' ) );
		}

		return $stylesheet;
	}

	/**
	 * Processes the CSS, to apply nesting.
	 *
	 * @since 6.2.0
	 * @since 6.6.0 Enforced 0-1-0 specificity for block custom CSS selectors.
	 *
	 * @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 = '';

		if ( empty( $css ) ) {
			return $processed_css;
		}

		// Split CSS nested rules.
		$parts = explode( '&', $css );
		foreach ( $parts as $part ) {
			if ( empty( $part ) ) {
				continue;
			}
			$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 .= ':root :where(' . 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];

				/*
				 * Handle pseudo elements such as ::before, ::after etc. Regex will also
				 * capture any leading combinator such as >, +, or ~, as well as spaces.
				 * This allows pseudo elements as descendants e.g. `.parent ::before`.
				 */
				$matches            = array();
				$has_pseudo_element = preg_match( '/([>+~\s]*::[a-zA-Z-]+)/', $nested_selector, $matches );
				$pseudo_part        = $has_pseudo_element ? $matches[1] : '';
				$nested_selector    = $has_pseudo_element ? str_replace( $pseudo_part, '', $nested_selector ) : $nested_selector;

				// Finalize selector and re-append pseudo element if required.
				$part_selector  = str_starts_with( $nested_selector, ' ' )
					? static::scope_selector( $selector, $nested_selector )
					: static::append_to_selector( $selector, $nested_selector );
				$final_selector = ":root :where($part_selector)$pseudo_part";

				$processed_css .= $final_selector . '{' . trim( $css_value ) . '}';
			}
		}
		return $processed_css;
	}

	/**
	 * Returns the global styles custom CSS.
	 *
	 * @since 6.2.0
	 * @deprecated 6.7.0 Use {@see 'get_stylesheet'} instead.
	 *
	 * @return string The global styles custom CSS.
	 */
	public function get_custom_css() {
		_deprecated_function( __METHOD__, '6.7.0', 'get_stylesheet' );
		// 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.
	 * @since 6.6.0 Updated layout style specificity to be compatible with overall 0-1-0 specificity in global styles.
	 *
	 * @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 === $selector ? ':root :where(.%2$s)%3$s' : ':root :where(%1$s-%2$s)%3$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,