heme_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;
}

/**
 * Removes leading and trailing _empty_ script tags.
 *
 * This is a helper meant to be used for literal script tag construction
 * within `wp_get_inline_script_tag()` or `wp_print_inline_script_tag()`.
 * It removes the literal values of "<script>" and "</script>" from
 * around an inline script after trimming whitespace. Typically this
 * is used in conjunction with output buffering, where `ob_get_clean()`
 * is passed as the `$contents` argument.
 *
 * Example:
 *
 *     // Strips exact literal empty SCRIPT tags.
 *     $js = '<script>sayHello();</script>;
 *     'sayHello();' === wp_remove_surrounding_empty_script_tags( $js );
 *
 *     // Otherwise if anything is different it warns in the JS console.
 *     $js = '<script type="text/javascript">console.log( "hi" );</script>';
 *     'console.error( ... )' === wp_remove_surrounding_empty_script_tags( $js );
 *
 * @since 6.4.0
 * @access private
 *
 * @see wp_print_inline_script_tag()
 * @see wp_get_inline_script_tag()
 *
 * @param string $contents Script body with manually created SCRIPT tag literals.
 * @return string Script body without surrounding script tag literals, or
 *                original contents if both exact literals aren't present.
 */
function wp_remove_surrounding_empty_script_tags( $contents ) {
	$contents = trim( $contents );
	$opener   = '<SCRIPT>';
	$closer   = '</SCRIPT>';

	if (
		strlen( $contents ) > strlen( $opener ) + strlen( $closer ) &&
		strtoupper( substr( $contents, 0, strlen( $opener ) ) ) === $opener &&
		strtoupper( substr( $contents, -strlen( $closer ) ) ) === $closer
	) {
		return substr( $contents, strlen( $opener ), -strlen( $closer ) );
	} else {
		$error_message = __( 'Expected string to start with script tag (without attributes) and end with script tag, with optional whitespace.' );
		_doing_it_wrong( __FUNCTION__, $error_message, '6.4' );
		return sprintf(
			'console.error(%s)',
			wp_json_encode(
				sprintf(
					/* translators: %s: wp_remove_surrounding_empty_script_tags() */
					__( 'Function %s used incorrectly in PHP.' ),
					'wp_remove_surrounding_empty_script_tags()'
				) . ' ' . $error_message
			)
		);
	}
}