ted, only the attribute name is added
	 * to $attributes_string for entries with a boolean value, and that are true.
	 */
	foreach ( $attributes as $attribute_name => $attribute_value ) {
		if ( is_bool( $attribute_value ) ) {
			if ( $attribute_value ) {
				$attributes_string .= $html5_script_support ? sprintf( ' %1$s="%2$s"', esc_attr( $attribute_name ), esc_attr( $attribute_name ) ) : ' ' . esc_attr( $attribute_name );
			}
		} else {
			$attributes_string .= sprintf( ' %1$s="%2$s"', esc_attr( $attribute_name ), esc_attr( $attribute_value ) );
		}
	}

	return $attributes_string;
}

/**
 * Formats `<script>` loader tags.
 *
 * It is possible to inject attributes in the `<script>` tag via the {@see 'wp_script_attributes'} filter.
 * Automatically injects type attribute if needed.
 *
 * @since 5.7.0
 *
 * @param array $attributes Key-value pairs representing `<script>` tag attributes.
 * @return string String containing `<script>` opening and closing tags.
 */
function wp_get_script_tag( $attributes ) {
	if ( ! isset( $attributes['type'] ) && ! is_admin() && ! current_theme_supports( 'html5', 'script' ) ) {
		$attributes['type'] = 'text/javascript';
	}
	/**
	 * Filters attributes to be added to a script tag.
	 *
	 * @since 5.7.0
	 *
	 * @param array $attributes Key-value pairs representing `<script>` tag attributes.
	 *                          Only the attribute name is added to the `<script>` tag for
	 *                          entries with a boolean value, and that are true.
	 */
	$attributes = apply_filters( 'wp_script_attributes', $attributes );

	return sprintf( "<script%s></script>\n", wp_sanitize_script_attributes( $attributes ) );
}

/**
 * Prints formatted `<script>` loader tag.
 *
 * It is possible to inject attributes in the `<script>` tag via the  {@see 'wp_script_attributes'}  filter.
 * Automatically injects type attribute if needed.
 *
 * @since 5.7.0
 *
 * @param array $attributes Key-value pairs representing `<script>` tag attributes.
 */
function wp_print_script_tag( $attributes ) {
	echo wp_get_script_tag( $attributes );
}

/**
 * Wraps inline JavaScript in `<script>` tag.
 *
 * It is possible to inject attributes in the `<script>` tag via the  {@see 'wp_script_attributes'}  filter.
 * Automatically injects type attribute if needed.
 *
 * @since 5.7.0
 *
 * @param string $javascript Inline JavaScript code.
 * @param array  $attributes Optional. Key-value pairs representing `<script>` tag attributes.
 * @return string String containing inline JavaScript code wrapped around `<script>` tag.
 */
function wp_get_inline_script_tag( $javascript, $attributes = array() ) {
	if ( ! isset( $attributes['type'] ) && ! is_admin() && ! current_theme_supports( 'html5', 'script' ) ) {
		$attributes['type'] = 'text/javascript';
	}
	/**
	 * Filters attributes to be added to a script tag.
	 *
	 * @since 5.7.0
	 *
	 * @param array  $attributes Key-value pairs representing `<script>` tag attributes.
	 *                           Only the attribute name is added to the `<script>` tag for
	 *                           entries with a boolean value, and that are true.
	 * @param string $javascript Inline JavaScript code.
	 */
	$attributes = apply_filters( 'wp_inline_script_attributes', $attributes, $javascript );

	$javascript = "\n" . trim( $javascript, "\n\r " ) . "\n";

	return sprintf( "<script%s>%s</script>\n", wp_sanitize_script_attributes( $attributes ), $javascript );
}

/**
 * Prints inline JavaScript wrapped in `<script>` tag.
 *
 * It is possible to inject attributes in the `<script>` tag via the  {@see 'wp_script_attributes'}  filter.
 * Automatically injects type attribute if needed.
 *
 * @since 5.7.0
 *
 * @param string $javascript Inline JavaScript code.
 * @param array  $attributes Optional. Key-value pairs representing `<script>` tag attributes.
 */
function wp_print_inline_script_tag( $javascript, $attributes = array() ) {
	echo wp_get_inline_script_tag( $javascript, $attributes );
}

/**
 * Allows small styles to be inlined.
 *
 * This improves performance and sustainability, and is opt-in. Stylesheets can opt in
 * by adding `path` data using `wp_style_add_data`, and defining the file's absolute path:
 *
 *     wp_style_add_data( $style_handle, 'path', $file_path );
 *
 * @since 5.8.0
 *
 * @global WP_Styles $wp_styles
 */
function wp_maybe_inline_styles() {
	global $wp_styles;

	$total_inline_limit = 20000;
	/**
	 * The maximum size of inlined styles in bytes.
	 *
	 * @since 5.8.0
	 *
	 * @param int $total_inline_limit The file-size threshold, in bytes. Default 20000.
	 */
	$total_inline_limit = apply_filters( 'styles_inline_size_limit', $total_inline_limit );

	$styles = array();

	// Build an array of styles that have a path defined.
	foreach ( $wp_styles->queue as $handle ) {
		if ( ! isset( $wp_styles->registered[ $handle ] ) ) {
			continue;
		}
		$src  = $wp_styles->registered[ $handle ]->src;
		$path = $wp_styles->get_data( $handle, 'path' );
		if ( $path && $src ) {
			$size = wp_filesize( $path );
			if ( ! $size ) {
				continue;
			}
			$styles[] = array(
				'handle' => $handle,
				'src'    => $src,
				'path'   => $path,
				'size'   => $size,
			);
		}
	}

	if ( ! empty( $styles ) ) {
		// Reorder styles array based on size.
		usort(
			$styles,
			static function( $a, $b ) {
				return ( $a['size'] <= $b['size'] ) ? -1 : 1;
			}
		);

		/*
		 * The total inlined size.
		 *
		 * On each iteration of the loop, if a style gets added inline the value of this var increases
		 * to reflect the total size of inlined styles.
		 */
		$total_inline_size = 0;

		// Loop styles.
		foreach ( $styles as $style ) {

			// Size check. Since styles are ordered by size, we can break the loop.
			if ( $total_inline_size + $style['size'] > $total_inline_limit ) {
				break;
			}

			// Get the styles if we don't already have them.
			$style['css'] = file_get_contents( $style['path'] );

			/*
			 * Check if the style contains relative URLs that need to be modified.
			 * URLs relative to the stylesheet's path should be converted to relative to the site's root.
			 */
			$style['css'] = _wp_normalize_relative_css_links( $style['css'], $style['src'] );

			// Set `src` to `false` and add styles inline.
			$wp_styles->registered[ $style['handle'] ]->src = false;
			if ( empty( $wp_styles->registered[ $style['handle'] ]->extra['after'] ) ) {
				$wp_styles->registered[ $style['handle'] ]->extra['after'] = array();
			}
			array_unshift( $wp_styles->registered[ $style['handle'] ]->extra['after'], $style['css'] );

			// Add the styles size to the $total_inline_size var.
			$total_inline_size += (int) $style['size'];
		}
	}
}

/**
 * Makes URLs relative to the WordPress installation.
 *
 * @since 5.9.0
 * @access private
 *
 * @param string $css            The CSS to make URLs relative to the WordPress installation.
 * @param string $stylesheet_url The URL to the stylesheet.
 *
 * @return string The CSS with URLs made relative to the WordPress installation.
 */
function _wp_normalize_relative_css_links( $css, $stylesheet_url ) {
	return preg_replace_callback(
		'#(url\s*\(\s*[\'"]?\s*)([^\'"\)]+)#',
		static function ( $matches ) use ( $stylesheet_url ) {
			list( , $prefix, $url ) = $matches;

			// Short-circuit if the URL does not require normalization.
			if (
				str_starts_with( $url, 'http:' ) ||
				str_starts_with( $url, 'https:' ) ||
				str_starts_with( $url, '//' ) ||
				str_starts_with( $url, '#' ) ||
				str_starts_with( $url, 'data:' )
			) {
				return $matches[0];
			}

			// Build the absolute URL.
			$absolute_url = dirname( $stylesheet_url ) . '/' . $url;
			$absolute_url = str_replace( '/./', '/', $absolute_url );

			// Convert to URL related to the site root.
			$url = wp_make_link_relative( $absolute_url );

			return $prefix . $url;
		},
		$css
	);
}

/**
 * Function that enqueues the CSS Custom Properties coming from theme.json.
 *
 * @since 5.9.0
 */
function wp_enqueue_global_styles_css_custom_properties() {
	wp_register_style( 'global-styles-css-custom-properties', false );
	wp_add_inline_style( 'global-styles-css-custom-properties', wp_get_global_stylesheet( array( 'variables' ) ) );
	wp_enqueue_style( 'global-styles-css-custom-properties' );
}

/**
 * Hooks inline styles in the proper place, depending on the active theme.
 *
 * @since 5.9.1
 * @since 6.1.0 Added the `$priority` parameter.
 *
 * For block themes, styles are loaded in the head.
 * For classic ones, styles are loaded in the body because the wp_head action happens before render_block.
 *
 * @link https://core.trac.wordpress.org/ticket/53494.
 *
 * @param string $style    String containing the CSS styles to be added.
 * @param int    $priority To set the priority for the add_action.
 */
function wp_enqueue_block_support_styles( $style, $priority = 10 ) {
	$action_hook_name = 'wp_footer';
	if ( wp_is_block_theme() ) {
		$action_hook_name = 'wp_head';
	}
	add_action(
		$action_hook_name,
		static function () use ( $style ) {
			echo "<style>$style</style>\n";
		},
		$priority
	);
}

/**
 * Fetches, processes and compiles stored core styles, then combines and renders them to the page.
 * Styles are stored via the style engine API.
 *
 * @link https://developer.wordpress.org/block-editor/reference-guides/packages/packages-style-engine/
 *
 * @since 6.1.0
 *
 * @param array $options {
 *     Optional. An array of options to pass to wp_style_engine_get_stylesheet_from_context().
 *     Default empty array.
 *
 *     @type bool $optimize Whether to optimize the CSS output, e.g., combine rules.
 *                          Default true.
 *     @type bool $prettify Whether to add new lines and indents to output.
 *                          Default to whether the `SCRIPT_DEBUG` constant is defined.
 * }
 */
function wp_enqueue_stored_styles( $options = array() ) {
	$is_block_theme   = wp_is_block_theme();
	$is_classic_theme = ! $is_block_theme;

	/*
	 * For block themes, this function prints stored styles in the header.
	 * For classic themes, in the footer.
	 */
	if (
		( $is_block_theme && doing_action( 'wp_footer' ) ) ||
		( $is_classic_theme && doing_action( 'wp_enqueue_scripts' ) )
	) {
		return;
	}

	$core_styles_keys         = array( 'block-supports' );
	$compiled_core_stylesheet = '';
	$style_tag_id             = 'core';
	// Adds comment if code is prettified to identify core styles sections in debugging.
	$should_prettify = isset( $options['prettify'] ) ? true === $options['prettify'] : defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG;
	foreach ( $core_styles_keys as $style_key ) {
		if ( $should_prettify ) {
			$compiled_core_stylesheet .= "/**\n * Core styles: $style_key\n */\n";
		}
		// Chains core store ids to signify what the styles contain.
		$style_tag_id             .= '-' . $style_key;
		$compiled_core_stylesheet .= wp_style_engine_get_stylesheet_from_context( $style_key, $options );
	}

	// Combines Core styles.
	if ( ! empty( $compiled_core_stylesheet ) ) {
		wp_register_style( $style_tag_id, false );
		wp_add_inline_style( $style_tag_id, $compiled_core_stylesheet );
		wp_enqueue_style( $style_tag_id );
	}

	// Prints out any other stores registered by themes or otherwise.
	$additional_stores = WP_Style_Engine_CSS_Rules_Store::get_stores();
	foreach ( array_keys( $additional_stores ) as $store_name ) {
		if ( in_array( $store_name, $core_styles_keys, true ) ) {
			continue;
		}
		$styles = wp_style_engine_get_stylesheet_from_context( $store_name, $options );
		if ( ! empty( $styles ) ) {
			$key = "wp-style-engine-$store_name";
			wp_register_style( $key, false );
			wp_add_inline_style( $key, $styles );
			wp_enqueue_style( $key );
		}
	}
}

/**
 * Enqueues a stylesheet for a specific block.
 *
 * If the theme has opted-in to separate-styles loading,
 * then the stylesheet will be enqueued on-render,
 * otherwise when the block inits.
 *
 * @since 5.9.0
 *
 * @param string $block_name The block-name, including namespace.
 * @param array  $args       {
 *     An array of arguments. See wp_register_style() for full information about each argument.
 *
 *     @type string           $handle The handle for the stylesheet.
 *     @type string|false     $src    The source URL of the stylesheet.
 *     @type string[]         $deps   Array of registered stylesheet handles this stylesheet depends on.
 *     @type string|bool|null $ver    Stylesheet version number.
 *     @type string           $media  The media for which this stylesheet has been defined.
 * }
 */
function wp_enqueue_block_style( $block_name, $args ) {
	$args = wp_parse_args(
		$args,
		array(
			'handle' => '',
			'src'    => '',
			'deps'   => array(),
			'ver'    => false,
			'media'  => 'all',
		)
	);

	/**
	 * Callback function to register and enqueue styles.
	 *
	 * @param string $content When the callback is used for the render_block filter,
	 *                        the content needs to be returned so the function parameter
	 *                        is to ensure the content exists.
	 * @return string Block content.
	 */
	$callback = static function( $content ) use ( $args ) {
		// Register the stylesheet.
		if ( ! empty( $args['src'] ) ) {
			wp_register_style( $args['handle'], $args['src'], $args['deps'], $args['ver'], $args['media'] );
		}

		// Add `path` data if provided.
		if ( isset( $args['path'] ) ) {
			wp_style_add_data( $args['handle'], 'path', $args['path'] );

			// Get the RTL file path.
			$rtl_file_path = str_replace( '.css', '-rtl.css', $args['path'] );

			// Add RTL stylesheet.
			if ( file_exists( $rtl_file_path ) ) {
				wp_style_add_data( $args['handle'], 'rtl', 'replace' );

				if ( is_rtl() ) {
					wp_style_add_data( $args['handle'], 'path', $rtl_file_path );
				}
			}
		}

		// Enqueue the stylesheet.
		wp_enqueue_style( $args['handle'] );

		return $content;
	};

	$hook = did_action( 'wp_enqueue_scripts' ) ? 'wp_footer' : 'wp_enqueue_scripts';
	if ( wp_should_load_separate_core_block_assets() ) {
		/**
		 * Callback function to register and enqueue styles.
		 *
		 * @param string $content The block content.
		 * @param array  $block   The full block, including name and attributes.
		 * @return string Block content.
		 */
		$callback_separate = static function( $content, $block ) use ( $block_name, $callback ) {
			if ( ! empty( $block['blockName'] ) && $block_name === $block['blockName'] ) {
				return $callback( $content );
			}
			return $content;
		};

		/*
		 * The filter's callback here is an anonymous function because
		 * using a named function in this case is not possible.
		 *
		 * The function cannot be unhooked, however, users are still able
		 * to dequeue the stylesheets registered/enqueued by the callback
		 * which is why in this case, using an anonymous function
		 * was deemed acceptable.
		 */
		add_filter( 'render_block', $callback_separate, 10, 2 );
		return;
	}

	/*
	 * The filter's callback here is an anonymous function because
	 * using a named function in this case is not possible.
	 *
	 * The function cannot be unhooked, however, users are still able
	 * to dequeue the stylesheets registered/enqueued by the callback
	 * which is why in this case, using an anonymous function
	 * was deemed acceptable.
	 */
	add_filter( $hook, $callback );

	// Enqueue assets in the editor.
	add_action( 'enqueue_block_assets', $callback );
}

/**
 * Runs the theme.json webfonts handler.
 *
 * Using `WP_Theme_JSON_Resolver`, it gets the fonts defined
 * in the `theme.json` for the current selection and style
 * variations, validates the font-face properties, generates
 * the '@font-face' style declarations, and then enqueues the
 * styles for both the editor and front-end.
 *
 * Design Notes:
 * This is not a public API, but rather an internal handler.
 * A future public Webfonts API will replace this stopgap code.
 *
 * This code design is intentional.
 *    a. It hides the inner-workings.
 *    b. It does not expose API ins or outs for consumption.
 *    c. It only works with a theme's `theme.json`.
 *
 * Why?
 *    a. To avoid backwards-compatibility issues when
 *       the Webfonts API is introduced in Core.
 *    b. To make `fontFace` declarations in `theme.json` work.
 *
 * @link  https://github.com/WordPress/gutenberg/issues/40472
 *
 * @since 6.0.0
 * @access private
 */
function _wp_theme_json_webfonts_handler() {
	// Block themes are unavailable during installation.
	if ( wp_installing() ) {
		return;
	}

	if ( ! wp_theme_has_theme_json() ) {
		return;
	}

	// Webfonts to be processed.
	$registered_webfonts = array();

	/**
	 * Gets the webfonts from theme.json.
	 *
	 * @since 6.0.0
	 *
	 * @return array Array of defined webfonts.
	 */
	$fn_get_webfonts_from_theme_json = static function() {
		// Get settings from theme.json.
		$settings = WP_Theme_JSON_Resolver::get_merged_data()->get_settings();

		// If in the editor, add webfonts defined in variations.
		if ( is_admin() || ( defined( 'REST_REQUEST' ) && REST_REQUEST ) ) {
			$variations = WP_Theme_JSON_Resolver::get_style_variations();
			foreach ( $variations as $variation ) {
				// Skip if fontFamilies are not defined in the variation.
				if ( empty( $variation['settings']['typography']['fontFamilies'] ) ) {
					continue;
				}

				// Initialize the array structure.
				if ( empty( $settings['typography'] ) ) {
					$settings['typography'] = array();
				}
				if ( empty( $settings['typography']['fontFamilies'] ) ) {
					$settings['typography']['fontFamilies'] = array();
				}
				if ( empty( $settings['typography']['fontFamilies']['theme'] ) ) {
					$settings['typography']['fontFamilies']['theme'] = array();
				}

				// Combine variations with settings. Remove duplicates.
				$settings['typography']['fontFamilies']['theme'] = array_merge( $settings['typography']['fontFamilies']['theme'], $variation['settings']['typography']['fontFamilies']['theme'] );
				$settings['typography']['fontFamilies']          = array_unique( $settings['typography']['fontFamilies'] );
			}
		}

		// Bail out early if there are no settings for webfonts.
		if ( empty( $settings['typography']['fontFamilies'] ) ) {
			return array();
		}

		$webfonts = array();

		// Look for fontFamilies.
		foreach ( $settings['typography']['fontFamilies'] as $font_families ) {
			foreach ( $font_families as $font_family ) {

				// Skip if fontFace is not defined.
				if ( empty( $font_family['fontFace'] ) ) {
					continue;
				}

				// Skip if fontFace is not an array of webfonts.
				if ( ! is_array( $font_family['fontFace'] ) ) {
					continue;
				}

				$webfonts = array_merge( $webfonts, $font_family['fontFace'] );
			}
		}

		return $webfonts;
	};

	/**
	 * Transforms each 'src' into an URI by replacing 'file:./'
	 * placeholder from theme.json.
	 *
	 * The absolute path to the webfont file(s) cannot be defined in
	 * theme.json. `file:./` is the placeholder which is replaced by
	 * the theme's URL path to the theme's root.
	 *
	 * @since 6.0.0
	 *
	 * @param array $src Webfont file(s) `src`.
	 * @return array Webfont's `src` in URI.
	 */
	$fn_transform_src_into_uri = static function( array $src ) {
		foreach ( $src as $key => $url ) {
			// Tweak the URL to be relative to the theme root.
			if ( ! str_starts_with( $url, 'file:./' ) ) {
				continue;
			}

			$src[ $key ] = get_theme_file_uri( str_replace( 'file:./', '', $url ) );
		}

		return $src;
	};

	/**
	 * Converts the font-face properties (i.e. keys) into kebab-case.
	 *
	 * @since 6.0.0
	 *
	 * @param array $font_face Font face to convert.
	 * @return array Font faces with each property in kebab-case format.
	 */
	$fn_convert_keys_to_kebab_case = static function( array $font_face ) {
		foreach ( $font_face as $property => $value ) {
			$kebab_case               = _wp_to_kebab_case( $property );
			$font_face[ $kebab_case ] = $value;
			if ( $kebab_case !== $property ) {
				unset( $font_face[ $property ] );
			}
		}

		return $font_face;
	};

	/**
	 * Validates a webfont.
	 *
	 * @since 6.0.0
	 *
	 * @param array $webfont The webfont arguments.
	 * @return array|false The validated webfont arguments, or false if the webfont is invalid.
	 */
	$fn_validate_webfont = static function( $webfont ) {
		$webfont = wp_parse_args(
			$webfont,
			array(
				'font-family'  => '',
				'font-style'   => 'normal',
				'font-weight'  => '400',
				'font-display' => 'fallback',
				'src'          => array(),
			)
		);

		// Check the font-family.
		if ( empty( $webfont['font-family'] ) || ! is_string( $webfont['font-family'] ) ) {
			trigger_error( __( 'Webfont font family must be a non-empty string.' ) );

			return false;
		}

		// Check that the `src` property is defined and a valid type.
		if ( empty( $webfont['src'] ) || ( ! is_string( $webfont['src'] ) && ! is_array( $webfont['src'] ) ) ) {
			trigger_error( __( 'Webfont src must be a non-empty string or an array of strings.' ) );

			return false;
		}

		// Validate the `src` property.
		foreach ( (array) $webfont['src'] as $src ) {
			if ( ! is_string( $src ) || '' === trim( $src ) ) {
				trigger_error( __( 'Each webfont src must be a non-empty string.' ) );

				return false;
			}
		}

		// Check the font-weight.
		if ( ! is_string( $webfont['font-weight'] ) && ! is_int( $webfont['font-weight'] ) ) {
			trigger_error( __( 'Webfont font weight must be a properly formatted string or integer.' ) );

			return false;
		}

		// Check the font-display.
		if ( ! in_array( $webfont['font-display'], array( 'auto', 'block', 'fallback', 'swap' ), true ) ) {
			$webfont['font-display'] = 'fallback';
		}

		$valid_props = array(
			'ascend-override',
			'descend-override',
			'font-display',
			'font-family',
			'font-stretch',
			'font-style',
			'font-weight',
			'font-variant',
			'font-feature-settings',
			'font-variation-settings',
			'line-gap-override',
			'size-adjust',
			'src',
			'unicode-range',
		);

		foreach ( $webfont as $prop => $value ) {
			if ( ! in_array( $prop, $valid_props, true ) ) {
				unset( $webfont[ $prop ] );
			}
		}

		return $webfont;
	};

	/**
	 * Registers webfonts declared in theme.json.
	 *
	 * @since 6.0.0
	 *
	 * @uses $registered_webfonts To access and update the registered webfonts registry (passed by reference).
	 * @uses $fn_get_webfonts_from_theme_json To run the function that gets the webfonts from theme.json.
	 * @uses $fn_convert_keys_to_kebab_case To run the function that converts keys into kebab-case.
	 * @uses $fn_validate_webfont To run the function that validates each font-face (webfont) from theme.json.
	 */
	$fn_register_webfonts = static function() use ( &$registered_webfonts, $fn_get_webfonts_from_theme_json, $fn_convert_keys_to_kebab_case, $fn_validate_webfont, $fn_transform_src_into_uri ) {
		$registered_webfonts = array();

		foreach ( $fn_get_webfonts_from_theme_json() as $webfont ) {
			if ( ! is_array( $webfont ) ) {
				continue;
			}

			$webfont = $fn_convert_keys_to_kebab_case( $webfont );

			$webfont = $fn_validate_webfont( $webfont );

			$webfont['src'] = $fn_transform_src_into_uri( (array) $webfont['src'] );

			// Skip if not valid.
			if ( empty( $webfont ) ) {
				continue;
			}

			$registered_webfonts[] = $webfont;
		}
	};

	/**
	 * Orders 'src' items to optimize for browser support.
	 *
	 * @since 6.0.0
	 *
	 * @param array $webfont Webfont to process.
	 * @return array Ordered `src` items.
	 */
	$fn_order_src = static function( array $webfont ) {
		$src         = array();
		$src_ordered = array();

		foreach ( $webfont['src'] as $url ) {
			// Add data URIs first.
			if ( str_starts_with( trim( $url ), 'data:' ) ) {
				$src_ordered[] = array(
					'url'    => $url,
					'format' => 'data',
				);
				continue;
			}
			$format         = pathinfo( $url, PATHINFO_EXTENSION );
			$src[ $format ] = $url;
		}

		// Add woff2.
		if ( ! empty( $src['woff2'] ) ) {
			$src_ordered[] = array(
				'url'    => sanitize_url( $src['woff2'] ),
				'format' => 'woff2',
			);
		}

		// Add woff.
		if ( ! empty( $src['woff'] ) ) {
			$src_ordered[] = array(
				'url'    => sanitize_url( $src['woff'] ),
				'format' => 'woff',
			);
		}

		// Add ttf.
		if ( ! empty( $src['ttf'] ) ) {
			$src_ordered[] = array(
				'url'    => sanitize_url( $src['ttf'] ),
				'format' => 'truetype',
			);
		}

		// Add eot.
		if ( ! empty( $src['eot'] ) ) {
			$src_ordered[] = array(
				'url'    => sanitize_url( $src['eot'] ),
				'format' => 'embedded-opentype',
			);
		}

		// Add otf.
		if ( ! empty( $src['otf'] ) ) {
			$src_ordered[] = array(
				'url'    => sanitize_url( $src['otf'] ),
				'format' => 'opentype',
			);
		}
		$webfont['src'] = $src_ordered;

		return $webfont;
	};

	/**
	 * Compiles the 'src' into valid CSS.
	 *
	 * @since 6.0.0
	 * @since 6.2.0 Removed local() CSS.
	 *
	 * @param string $font_family Font family.
	 * @param array  $value       Value to process.
	 * @return string The CSS.
	 */
	$fn_compile_src = static function( $font_family, array $value ) {
		$src = '';

		foreach ( $value as $item ) {
			$src .= ( 'data' === $item['format'] )
				? ", url({$item['url']})"
				: ", url('{$item['url']}') format('{$item['format']}')";
		}

		$src = ltrim( $src, ', ' );

		return $src;
	};

	/**
	 * Compiles the font variation settings.
	 *
	 * @since 6.0.0
	 *
	 * @param array $font_variation_settings Array of font variation settings.
	 * @return string The CSS.
	 */
	$fn_compile_variations = static function( array $font_variation_settings ) {
		$variations = '';

		foreach ( $font_variation_settings as $key => $value ) {
			$variations .= "$key $value";
		}

		return $variations;
	};

	/**
	 * Builds the font-family's CSS.
	 *
	 * @since 6.0.0
	 *
	 * @uses $fn_compile_src To run the function that compiles the src.
	 * @uses $fn_compile_variations To run the function that compiles the variations.
	 *
	 * @param array $webfont Webfont to process.
	 * @return string This font-family's CSS.
	 */
	$fn_build_font_face_css = static function( array $webfont ) use ( $fn_compile_src, $fn_compile_variations ) {
		$css = '';

		// Wrap font-family in quotes if it contains spaces.
		if (
			str_contains( $webfont['font-family'], ' ' ) &&
			! str_contains( $webfont['font-family'], '"' ) &&
			! str_contains( $webfont['font-family'], "'" )
		) {
			$webfont['font-family'] = '"' . $webfont['font-family'] . '"';
		}

		foreach ( $webfont as $key => $value ) {
			/*
			 * Skip "provider", since it's for internal API use,
			 * and not a valid CSS property.
			 */
			if ( 'provider' === $key ) {
				continue;
			}

			// Compile the "src" parameter.
			if ( 'src' === $key ) {
				$value = $fn_compile_src( $webfont['font-family'], $value );
			}

			// If font-variation-settings is an array, convert it to a string.
			if ( 'font-variation-settings' === $key && is_array( $value ) ) {
				$value = $fn_compile_variations( $value );
			}

			if ( ! empty( $value ) ) {
				$css .= "$key:$value;";
			}
		}

		return $css;
	};

	/**
	 * Gets the '@font-face' CSS styles for locally-hosted font files.
	 *
	 * @since 6.0.0
	 *
	 * @uses $registered_webfonts To access and update the registered webfonts registry (passed by reference).
	 * @uses $fn_order_src To run the function that orders the src.
	 * @uses $fn_build_font_face_css To run the function that builds the font-face CSS.
	 *
	 * @return string The `@font-face` CSS.
	 */
	$fn_get_css = static function() use ( &$registered_webfonts, $fn_order_src, $fn_build_font_face_css ) {
		$css = '';

		foreach ( $registered_webfonts as $webfont ) {
			// Order the webfont's `src` items to optimize for browser support.
			$webfont = $fn_order_src( $webfont );

			// Build the @font-face CSS for this webfont.
			$css .= '@font-face{' . $fn_build_font_face_css( $webfont ) . '}';
		}

		return $css;
	};

	/**
	 * Generates and enqueues webfonts styles.
	 *
	 * @since 6.0.0
	 *
	 * @uses $fn_get_css To run the function that gets the CSS.
	 */
	$fn_generate_and_enqueue_styles = static function() use ( $fn_get_css ) {
		// Generate the styles.
		$styles = $fn_get_css();

		// Bail out if there are no styles to enqueue.
		if ( '' === $styles ) {
			return;
		}

		// Enqueue the stylesheet.
		wp_register_style( 'wp-webfonts', '' );
		wp_enqueue_style( 'wp-webfonts' );

		// Add the styles to the stylesheet.
		wp_add_inline_style( 'wp-webfonts', $styles );
	};

	/**
	 * Generates and enqueues editor styles.
	 *
	 * @since 6.0.0
	 *
	 * @uses $fn_get_css To run the function that gets the CSS.
	 */
	$fn_generate_and_enqueue_editor_styles = static function() use ( $fn_get_css ) {
		// Generate the styles.
		$styles = $fn_get_css();

		// Bail out if there are no styles to enqueue.
		if ( '' === $styles ) {
			return;
		}

		wp_add_inline_style( 'wp-block-library', $styles );
	};

	add_action( 'wp_loaded', $fn_register_webfonts );
	add_action( 'wp_enqueue_scripts', $fn_generate_and_enqueue_styles );
	add_action( 'admin_init', $fn_generate_and_enqueue_editor_styles );
}

/**
 * Loads classic theme styles on classic themes in the frontend.
 *
 * This is needed for backwards compatibility for button blocks specifically.
 *
 * @since 6.1.0
 */
function wp_enqueue_classic_theme_styles() {
	if ( ! wp_theme_has_theme_json() ) {
		$suffix = wp_scripts_get_suffix();
		wp_register_style( 'classic-theme-styles', '/' . WPINC . "/css/classic-themes$suffix.css" );
		wp_style_add_data( 'classic-theme-styles', 'path', ABSPATH . WPINC . "/css/classic-themes$suffix.css" );
		wp_enqueue_style( 'classic-theme-styles' );
	}
}

/**
 * Loads classic theme styles on classic themes in the editor.
 *
 * This is needed for backwards compatibility for button blocks specifically.
 *
 * @since 6.1.0
 *
 * @param array $editor_settings The array of editor settings.
 * @return array A filtered array of editor settings.
 */
function wp_add_editor_classic_theme_styles( $editor_settings ) {
	if ( wp_theme_has_theme_json() ) {
		return $editor_settings;
	}

	$suffix               = wp_scripts_get_suffix();
	$classic_theme_styles = ABSPATH . WPINC . "/css/classic-themes$suffix.css";

	/*
	 * This follows the pattern of get_block_editor_theme_styles,
	 * but we can't use get_block_editor_theme_styles directly as it
	 * only handles external files or theme files.
	 */
	$classic_theme_styles_settings = array(
		'css'            => file_get_contents( $classic_theme_styles ),
		'__unstableType' => 'core',
		'isGlobalStyles' => false,
	);

	// Add these settings to the start of the array so that themes can override them.
	array_unshift( $editor_settings['styles'], $classic_theme_styles_settings );

	return $editor_settings;
}