<?php
/**
 * Theme, template, and stylesheet functions.
 *
 * @package ClassicPress
 * @subpackage Theme
 */

/**
 * Returns an array of WP_Theme objects based on the arguments.
 *
 * Despite advances over get_themes(), this function is quite expensive, and grows
 * linearly with additional themes. Stick to wp_get_theme() if possible.
 *
 * @since 3.4.0
 *
 * @global array $wp_theme_directories
 *
 * @param array $args {
 *     Optional. The search arguments.
 *
 *     @type mixed $errors  True to return themes with errors, false to return
 *                          themes without errors, null to return all themes.
 *                          Default false.
 *     @type mixed $allowed (Multisite) True to return only allowed themes for a site.
 *                          False to return only disallowed themes for a site.
 *                          'site' to return only site-allowed themes.
 *                          'network' to return only network-allowed themes.
 *                          Null to return all themes. Default null.
 *     @type int   $blog_id (Multisite) The blog ID used to calculate which themes
 *                          are allowed. Default 0, synonymous for the current blog.
 * }
 * @return WP_Theme[] Array of WP_Theme objects.
 */
function wp_get_themes( $args = array() ) {
	global $wp_theme_directories;

	$defaults = array(
		'errors'  => false,
		'allowed' => null,
		'blog_id' => 0,
	);
	$args     = wp_parse_args( $args, $defaults );

	$theme_directories = search_theme_directories();

	if ( is_array( $wp_theme_directories ) && count( $wp_theme_directories ) > 1 ) {
		// Make sure the active theme wins out, in case search_theme_directories() picks the wrong
		// one in the case of a conflict. (Normally, last registered theme root wins.)
		$current_theme = get_stylesheet();
		if ( isset( $theme_directories[ $current_theme ] ) ) {
			$root_of_current_theme = get_raw_theme_root( $current_theme );
			if ( ! in_array( $root_of_current_theme, $wp_theme_directories, true ) ) {
				$root_of_current_theme = WP_CONTENT_DIR . $root_of_current_theme;
			}
			$theme_directories[ $current_theme ]['theme_root'] = $root_of_current_theme;
		}
	}

	if ( empty( $theme_directories ) ) {
		return array();
	}

	if ( is_multisite() && null !== $args['allowed'] ) {
		$allowed = $args['allowed'];
		if ( 'network' === $allowed ) {
			$theme_directories = array_intersect_key( $theme_directories, WP_Theme::get_allowed_on_network() );
		} elseif ( 'site' === $allowed ) {
			$theme_directories = array_intersect_key( $theme_directories, WP_Theme::get_allowed_on_site( $args['blog_id'] ) );
		} elseif ( $allowed ) {
			$theme_directories = array_intersect_key( $theme_directories, WP_Theme::get_allowed( $args['blog_id'] ) );
		} else {
			$theme_directories = array_diff_key( $theme_directories, WP_Theme::get_allowed( $args['blog_id'] ) );
		}
	}

	$themes         = array();
	static $_themes = array();

	foreach ( $theme_directories as $theme => $theme_root ) {
		if ( isset( $_themes[ $theme_root['theme_root'] . '/' . $theme ] ) ) {
			$themes[ $theme ] = $_themes[ $theme_root['theme_root'] . '/' . $theme ];
		} else {
			$themes[ $theme ] = new WP_Theme( $theme, $theme_root['theme_root'] );

			$_themes[ $theme_root['theme_root'] . '/' . $theme ] = $themes[ $theme ];
		}
	}

	if ( null !== $args['errors'] ) {
		foreach ( $themes as $theme => $wp_theme ) {
			if ( $wp_theme->errors() != $args['errors'] ) {
				unset( $themes[ $theme ] );
			}
		}
	}

	return $themes;
}

/**
 * Gets a WP_Theme object for a theme.
 *
 * @since 3.4.0
 *
 * @global array $wp_theme_directories
 *
 * @param string $stylesheet Optional. Directory name for the theme. Defaults to active theme.
 * @param string $theme_root Optional. Absolute path of the theme root to look in.
 *                           If not specified, get_raw_theme_root() is used to calculate
 *                           the theme root for the $stylesheet provided (or active theme).
 * @return WP_Theme Theme object. Be sure to check the object's exists() method
 *                  if you need to confirm the theme's existence.
 */
function wp_get_theme( $stylesheet = '', $theme_root = '' ) {
	global $wp_theme_directories;

	if ( empty( $stylesheet ) ) {
		$stylesheet = get_stylesheet();
	}

	if ( empty( $theme_root ) ) {
		$theme_root = get_raw_theme_root( $stylesheet );
		if ( false === $theme_root ) {
			$theme_root = WP_CONTENT_DIR . '/themes';
		} elseif ( ! in_array( $theme_root, (array) $wp_theme_directories, true ) ) {
			$theme_root = WP_CONTENT_DIR . $theme_root;
		}
	}

	return new WP_Theme( $stylesheet, $theme_root );
}

/**
 * Clears the cache held by get_theme_roots() and WP_Theme.
 *
 * @since 3.5.0
 * @param bool $clear_update_cache Whether to clear the theme updates cache.
 */
function wp_clean_themes_cache( $clear_update_cache = true ) {
	if ( $clear_update_cache ) {
		delete_site_transient( 'update_themes' );
	}
	search_theme_directories( true );
	foreach ( wp_get_themes( array( 'errors' => null ) ) as $theme ) {
		$theme->cache_delete();
	}
}

/**
 * Whether a child theme is in use.
 *
 * @since 3.0.0
 *
 * @return bool True if a child theme is in use, false otherwise.
 */
function is_child_theme() {
	return ( TEMPLATEPATH !== STYLESHEETPATH );
}

/**
 * Retrieves name of the current stylesheet.
 *
 * The theme name that is currently set as the front end theme.
 *
 * For all intents and purposes, the template name and the stylesheet name
 * are going to be the same for most cases.
 *
 * @since 1.5.0
 *
 * @return string Stylesheet name.
 */
function get_stylesheet() {
	/**
	 * Filters the name of current stylesheet.
	 *
	 * @since 1.5.0
	 *
	 * @param string $stylesheet Name of the current stylesheet.
	 */
	return apply_filters( 'stylesheet', get_option( 'stylesheet' ) );
}

/**
 * Retrieves stylesheet directory path for the active theme.
 *
 * @since 1.5.0
 *
 * @return string Path to active theme's stylesheet directory.
 */
function get_stylesheet_directory() {
	$stylesheet     = get_stylesheet();
	$theme_root     = get_theme_root( $stylesheet );
	$stylesheet_dir = "$theme_root/$stylesheet";

	/**
	 * Filters the stylesheet directory path for the active theme.
	 *
	 * @since 1.5.0
	 *
	 * @param string $stylesheet_dir Absolute path to the active theme.
	 * @param string $stylesheet     Directory name of the active theme.
	 * @param string $theme_root     Absolute path to themes directory.
	 */
	return apply_filters( 'stylesheet_directory', $stylesheet_dir, $stylesheet, $theme_root );
}

/**
 * Retrieves stylesheet directory URI for the active theme.
 *
 * @since 1.5.0
 *
 * @return string URI to active theme's stylesheet directory.
 */
function get_stylesheet_directory_uri() {
	$stylesheet         = str_replace( '%2F', '/', rawurlencode( get_stylesheet() ) );
	$theme_root_uri     = get_theme_root_uri( $stylesheet );
	$stylesheet_dir_uri = "$theme_root_uri/$stylesheet";

	/**
	 * Filters the stylesheet directory URI.
	 *
	 * @since 1.5.0
	 *
	 * @param string $stylesheet_dir_uri Stylesheet directory URI.
	 * @param string $stylesheet         Name of the activated theme's directory.
	 * @param string $theme_root_uri     Themes root URI.
	 */
	return apply_filters( 'stylesheet_directory_uri', $stylesheet_dir_uri, $stylesheet, $theme_root_uri );
}

/**
 * Retrieves stylesheet URI for the active theme.
 *
 * The stylesheet file name is 'style.css' which is appended to the stylesheet directory URI path.
 * See get_stylesheet_directory_uri().
 *
 * @since 1.5.0
 *
 * @return string URI to active theme's stylesheet.
 */
function get_stylesheet_uri() {
	$stylesheet_dir_uri = get_stylesheet_directory_uri();
	$stylesheet_uri     = $stylesheet_dir_uri . '/style.css';
	/**
	 * Filters the URI of the active theme stylesheet.
	 *
	 * @since 1.5.0
	 *
	 * @param string $stylesheet_uri     Stylesheet URI for the active theme/child theme.
	 * @param string $stylesheet_dir_uri Stylesheet directory URI for the active theme/child theme.
	 */
	return apply_filters( 'stylesheet_uri', $stylesheet_uri, $stylesheet_dir_uri );
}

/**
 * Retrieves the localized stylesheet URI.
 *
 * The stylesheet directory for the localized stylesheet files are located, by
 * default, in the base theme directory. The name of the locale file will be the
 * locale followed by '.css'. If that does not exist, then the text direction
 * stylesheet will be checked for existence, for example 'ltr.css'.
 *
 * The theme may change the location of the stylesheet directory by either using
 * the {@see 'stylesheet_directory_uri'} or {@see 'locale_stylesheet_uri'} filters.
 *
 * If you want to change the location of the stylesheet files for the entire
 * WordPress workflow, then change the former. If you just have the locale in a
 * separate folder, then change the latter.
 *
 * @since 2.1.0
 *
 * @global WP_Locale $wp_locale WordPress date and time locale object.
 *
 * @return string URI to active theme's localized stylesheet.
 */
function get_locale_stylesheet_uri() {
	global $wp_locale;
	$stylesheet_dir_uri = get_stylesheet_directory_uri();
	$dir                = get_stylesheet_directory();
	$locale             = get_locale();
	if ( file_exists( "$dir/$locale.css" ) ) {
		$stylesheet_uri = "$stylesheet_dir_uri/$locale.css";
	} elseif ( ! empty( $wp_locale->text_direction ) && file_exists( "$dir/{$wp_locale->text_direction}.css" ) ) {
		$stylesheet_uri = "$stylesheet_dir_uri/{$wp_locale->text_direction}.css";
	} else {
		$stylesheet_uri = '';
	}
	/**
	 * Filters the localized stylesheet URI.
	 *
	 * @since 2.1.0
	 *
	 * @param string $stylesheet_uri     Localized stylesheet URI.
	 * @param string $stylesheet_dir_uri Stylesheet directory URI.
	 */
	return apply_filters( 'locale_stylesheet_uri', $stylesheet_uri, $stylesheet_dir_uri );
}

/**
 * Retrieves name of the active theme.
 *
 * @since 1.5.0
 *
 * @return string Template name.
 */
function get_template() {
	/**
	 * Filters the name of the active theme.
	 *
	 * @since 1.5.0
	 *
	 * @param string $template active theme's directory name.
	 */
	return apply_filters( 'template', get_option( 'template' ) );
}

/**
 * Retrieves template directory path for the active theme.
 *
 * @since 1.5.0
 *
 * @return string Path to active theme's template directory.
 */
function get_template_directory() {
	$template     = get_template();
	$theme_root   = get_theme_root( $template );
	$template_dir = "$theme_root/$template";

	/**
	 * Filters the active theme directory path.
	 *
	 * @since 1.5.0
	 *
	 * @param string $template_dir The path of the active theme directory.
	 * @param string $template     Directory name of the active theme.
	 * @param string $theme_root   Absolute path to the themes directory.
	 */
	return apply_filters( 'template_directory', $template_dir, $template, $theme_root );
}

/**
 * Retrieves template directory URI for the active theme.
 *
 * @since 1.5.0
 *
 * @return string URI to active theme's template directory.
 */
function get_template_directory_uri() {
	$template         = str_replace( '%2F', '/', rawurlencode( get_template() ) );
	$theme_root_uri   = get_theme_root_uri( $template );
	$template_dir_uri = "$theme_root_uri/$template";

	/**
	 * Filters the active theme directory URI.
	 *
	 * @since 1.5.0
	 *
	 * @param string $template_dir_uri The URI of the active theme directory.
	 * @param string $template         Directory name of the active theme.
	 * @param string $theme_root_uri   The themes root URI.
	 */
	return apply_filters( 'template_directory_uri', $template_dir_uri, $template, $theme_root_uri );
}

/**
 * Retrieves theme roots.
 *
 * @since 2.9.0
 *
 * @global array $wp_theme_directories
 *
 * @return array|string An array of theme roots keyed by template/stylesheet
 *                      or a single theme root if all themes have the same root.
 */
function get_theme_roots() {
	global $wp_theme_directories;

	if ( ! is_array( $wp_theme_directories ) || count( $wp_theme_directories ) <= 1 ) {
		return '/themes';
	}

	$theme_roots = get_site_transient( 'theme_roots' );
	if ( false === $theme_roots ) {
		search_theme_directories( true ); // Regenerate the transient.
		$theme_roots = get_site_transient( 'theme_roots' );
	}
	return $theme_roots;
}

/**
 * Registers a directory that contains themes.
 *
 * @since 2.9.0
 *
 * @global array $wp_theme_directories
 *
 * @param string $directory Either the full filesystem path to a theme folder
 *                          or a folder within WP_CONTENT_DIR.
 * @return bool True if successfully registered a directory that contains themes,
 *              false if the directory does not exist.
 */
function register_theme_directory( $directory ) {
	global $wp_theme_directories;

	if ( ! file_exists( $directory ) ) {
		// Try prepending as the theme directory could be relative to the content directory.
		$directory = WP_CONTENT_DIR . '/' . $directory;
		// If this directory does not exist, return and do not register.
		if ( ! file_exists( $directory ) ) {
			return false;
		}
	}

	if ( ! is_array( $wp_theme_directories ) ) {
		$wp_theme_directories = array();
	}

	$untrailed = untrailingslashit( $directory );
	if ( ! empty( $untrailed ) && ! in_array( $untrailed, $wp_theme_directories, true ) ) {
		$wp_theme_directories[] = $untrailed;
	}

	return true;
}

/**
 * Searches all registered theme directories for complete and valid themes.
 *
 * @since 2.9.0
 *
 * @global array $wp_theme_directories
 *
 * @param bool $force Optional. Whether to force a new directory scan. Default false.
 * @return array|false Valid themes found on success, false on failure.
 */
function search_theme_directories( $force = false ) {
	global $wp_theme_directories;
	static $found_themes = null;

	if ( empty( $wp_theme_directories ) ) {
		return false;
	}

	if ( ! $force && isset( $found_themes ) ) {
		return $found_themes;
	}

	$found_themes = array();

	$wp_theme_directories = (array) $wp_theme_directories;
	$relative_theme_roots = array();

	/*
	 * Set up maybe-relative, maybe-absolute array of theme directories.
	 * We always want to return absolute, but we need to cache relative
	 * to use in get_theme_root().
	 */
	foreach ( $wp_theme_directories as $theme_root ) {
		if ( str_starts_with( $theme_root, WP_CONTENT_DIR ) ) {
			$relative_theme_roots[ str_replace( WP_CONTENT_DIR, '', $theme_root ) ] = $theme_root;
		} else {
			$relative_theme_roots[ $theme_root ] = $theme_root;
		}
	}

	/**
	 * Filters whether to get the cache of the registered theme directories.
	 *
	 * @since 3.4.0
	 *
	 * @param bool   $cache_expiration Whether to get the cache of the theme directories. Default false.
	 * @param string $context          The class or function name calling the filter.
	 */
	$cache_expiration = apply_filters( 'wp_cache_themes_persistently', false, 'search_theme_directories' );

	if ( $cache_expiration ) {
		$cached_roots = get_site_transient( 'theme_roots' );
		if ( is_array( $cached_roots ) ) {
			foreach ( $cached_roots as $theme_dir => $theme_root ) {
				// A cached theme root is no longer around, so skip it.
				if ( ! isset( $relative_theme_roots[ $theme_root ] ) ) {
					continue;
				}
				$found_themes[ $theme_dir ] = array(
					'theme_file' => $theme_dir . '/style.css',
					'theme_root' => $relative_theme_roots[ $theme_root ], // Convert relative to absolute.
				);
			}
			return $found_themes;
		}
		if ( ! is_int( $cache_expiration ) ) {
			$cache_expiration = 30 * MINUTE_IN_SECONDS;
		}
	} else {
		$cache_expiration = 30 * MINUTE_IN_SECONDS;
	}

	/* Loop the registered theme directories and extract all themes */
	foreach ( $wp_theme_directories as $theme_root ) {

		// Start with directories in the root of the active theme directory.
		$dirs = @ scandir( $theme_root );
		if ( ! $dirs ) {
			trigger_error( "$theme_root is not readable", E_USER_NOTICE );
			continue;
		}
		foreach ( $dirs as $dir ) {
			if ( ! is_dir( $theme_root . '/' . $dir ) || '.' === $dir[0] || 'CVS' === $dir ) {
				continue;
			}
			if ( file_exists( $theme_root . '/' . $dir . '/style.css' ) ) {
				// wp-content/themes/a-single-theme
				// wp-content/themes is $theme_root, a-single-theme is $dir.
				$found_themes[ $dir ] = array(
					'theme_file' => $dir . '/style.css',
					'theme_root' => $theme_root,
				);
			} else {
				$found_theme = false;
				// wp-content/themes/a-folder-of-themes/*
				// wp-content/themes is $theme_root, a-folder-of-themes is $dir, then themes are $sub_dirs.
				$sub_dirs = @ scandir( $theme_root . '/' . $dir );
				if ( ! $sub_dirs ) {
					trigger_error( "$theme_root/$dir is not readable", E_USER_NOTICE );
					continue;
				}
				foreach ( $sub_dirs as $sub_dir ) {
					if ( ! is_dir( $theme_root . '/' . $dir . '/' . $sub_dir ) || '.' === $dir[0] || 'CVS' === $dir ) {
						continue;
					}
					if ( ! file_exists( $theme_root . '/' . $dir . '/' . $sub_dir . '/style.css' ) ) {
						continue;
					}
					$found_themes[ $dir . '/' . $sub_dir ] = array(
						'theme_file' => $dir . '/' . $sub_dir . '/style.css',
						'theme_root' => $theme_root,
					);
					$found_theme                           = true;
				}
				// Never mind the above, it's just a theme missing a style.css.
				// Return it; WP_Theme will catch the error.
				if ( ! $found_theme ) {
					$found_themes[ $dir ] = array(
						'theme_file' => $dir . '/style.css',
						'theme_root' => $theme_root,
					);
				}
			}
		}
	}

	asort( $found_themes );

	$theme_roots          = array();
	$relative_theme_roots = array_flip( $relative_theme_roots );

	foreach ( $found_themes as $theme_dir => $theme_data ) {
		$theme_roots[ $theme_dir ] = $relative_theme_roots[ $theme_data['theme_root'] ]; // Convert absolute to relative.
	}

	if ( get_site_transient( 'theme_roots' ) != $theme_roots ) {
		set_site_transient( 'theme_roots', $theme_roots, $cache_expiration );
	}

	return $found_themes;
}

/**
 * Retrieves path to themes directory.
 *
 * Does not have trailing slash.
 *
 * @since 1.5.0
 *
 * @global array $wp_theme_directories
 *
 * @param string $stylesheet_or_template Optional. The stylesheet or template name of the theme.
 *                                       Default is to leverage the main theme root.
 * @return string Themes directory path.
 */
function get_theme_root( $stylesheet_or_template = '' ) {
	global $wp_theme_directories;

	$theme_root = '';

	if ( $stylesheet_or_template ) {
		$theme_root = get_raw_theme_root( $stylesheet_or_template );
		if ( $theme_root ) {
			// Always prepend WP_CONTENT_DIR unless the root currently registered as a theme directory.
			// This gives relative theme roots the benefit of the doubt when things go haywire.
			if ( ! in_array( $theme_root, (array) $wp_theme_directories, true ) ) {
				$theme_root = WP_CONTENT_DIR . $theme_root;
			}
		}
	}

	if ( ! $theme_root ) {
		$theme_root = WP_CONTENT_DIR . '/themes';
	}

	/**
	 * Filters the absolute path to the themes directory.
	 *
	 * @since 1.5.0
	 *
	 * @param string $theme_root Absolute path to themes directory.
	 */
	return apply_filters( 'theme_root', $theme_root );
}

/**
 * Retrieves URI for themes directory.
 *
 * Does not have trailing slash.
 *
 * @since 1.5.0
 *
 * @global array $wp_theme_directories
 *
 * @param string $stylesheet_or_template Optional. The stylesheet or template name of the theme.
 *                                       Default is to leverage the main theme root.
 * @param string $theme_root             Optional. The theme root for which calculations will be based,
 *                                       preventing the need for a get_raw_theme_root() call. Default empty.
 * @return string Themes directory URI.
 */
function get_theme_root_uri( $stylesheet_or_template = '', $theme_root = '' ) {
	global $wp_theme_directories;

	if ( $stylesheet_or_template && ! $theme_root ) {
		$theme_root = get_raw_theme_root( $stylesheet_or_template );
	}

	if ( $stylesheet_or_template && $theme_root ) {
		if ( in_array( $theme_root, (array) $wp_theme_directories, true ) ) {
			// Absolute path. Make an educated guess. YMMV -- but note the filter below.
			if ( str_starts_with( $theme_root, WP_CONTENT_DIR ) ) {
				$theme_root_uri = content_url( str_replace( WP_CONTENT_DIR, '', $theme_root ) );
			} elseif ( str_starts_with( $theme_root, ABSPATH ) ) {
				$theme_root_uri = site_url( str_replace( ABSPATH, '', $theme_root ) );
			} elseif ( str_starts_with( $theme_root, WP_PLUGIN_DIR ) || str_starts_with( $theme_root, WPMU_PLUGIN_DIR ) ) {
				$theme_root_uri = plugins_url( basename( $theme_root ), $theme_root );
			} else {
				$theme_root_uri = $theme_root;
			}
		} else {
			$theme_root_uri = content_url( $theme_root );
		}
	} else {
		$theme_root_uri = content_url( 'themes' );
	}

	/**
	 * Filters the URI for themes directory.
	 *
	 * @since 1.5.0
	 *
	 * @param string $theme_root_uri         The URI for themes directory.
	 * @param string $siteurl                WordPress web address which is set in General Options.
	 * @param string $stylesheet_or_template The stylesheet or template name of the theme.
	 */
	return apply_filters( 'theme_root_uri', $theme_root_uri, get_option( 'siteurl' ), $stylesheet_or_template );
}

/**
 * Gets the raw theme root relative to the content directory with no filters applied.
 *
 * @since 3.1.0
 *
 * @global array $wp_theme_directories
 *
 * @param string $stylesheet_or_template The stylesheet or template name of the theme.
 * @param bool   $skip_cache             Optional. Whether to skip the cache.
 *                                       Defaults to false, meaning the cache is used.
 * @return string Theme root.
 */
function get_raw_theme_root( $stylesheet_or_template, $skip_cache = false ) {
	global $wp_theme_directories;

	if ( ! is_array( $wp_theme_directories ) || count( $wp_theme_directories ) <= 1 ) {
		return '/themes';
	}

	$theme_root = false;

	// If requesting the root for the active theme, consult options to avoid calling get_theme_roots().
	if ( ! $skip_cache ) {
		if ( get_option( 'stylesheet' ) == $stylesheet_or_template ) {
			$theme_root = get_option( 'stylesheet_root' );
		} elseif ( get_option( 'template' ) == $stylesheet_or_template ) {
			$theme_root = get_option( 'template_root' );
		}
	}

	if ( empty( $theme_root ) ) {
		$theme_roots = get_theme_roots();
		if ( ! empty( $theme_roots[ $stylesheet_or_template ] ) ) {
			$theme_root = $theme_roots[ $stylesheet_or_template ];
		}
	}

	return $theme_root;
}

/**
 * Displays localized stylesheet link element.
 *
 * @since 2.1.0
 */
function locale_stylesheet() {
	$stylesheet = get_locale_stylesheet_uri();
	if ( empty( $stylesheet ) ) {
		return;
	}

	printf(
		'<link rel="stylesheet" href="%s" media="screen">',
		$stylesheet
	);
}

/**
 * Switches the theme.
 *
 * Accepts one argument: $stylesheet of the theme. It also accepts an additional function signature
 * of two arguments: $template then $stylesheet. This is for backward compatibility.
 *
 * @since 2.5.0
 *
 * @global array                $wp_theme_directories
 * @global WP_Customize_Manager $wp_customize
 * @global array                $sidebars_widgets
 * @global array                $wp_registered_sidebars
 *
 * @param string $stylesheet Stylesheet name.
 */
function switch_theme( $stylesheet ) {
	global $wp_theme_directories, $wp_customize, $sidebars_widgets, $wp_registered_sidebars;

	$requirements = validate_theme_requirements( $stylesheet );
	if ( is_wp_error( $requirements ) ) {
		wp_die( $requirements );
	}

	$_sidebars_widgets = null;
	if ( 'wp_ajax_customize_save' === current_action() ) {
		$old_sidebars_widgets_data_setting = $wp_customize->get_setting( 'old_sidebars_widgets_data' );
		if ( $old_sidebars_widgets_data_setting ) {
			$_sidebars_widgets = $wp_customize->post_value( $old_sidebars_widgets_data_setting );
		}
	} elseif ( is_array( $sidebars_widgets ) ) {
		$_sidebars_widgets = $sidebars_widgets;
	}

	if ( is_array( $_sidebars_widgets ) ) {
		set_theme_mod(
			'sidebars_widgets',
			array(
				'time' => time(),
				'data' => $_sidebars_widgets,
			)
		);
	}

	$nav_menu_locations = get_theme_mod( 'nav_menu_locations' );
	update_option( 'theme_switch_menu_locations', $nav_menu_locations );

	if ( func_num_args() > 1 ) {
		$stylesheet = func_get_arg( 1 );
	}

	$old_theme = wp_get_theme();
	$new_theme = wp_get_theme( $stylesheet );
	$template  = $new_theme->get_template();

	if ( wp_is_recovery_mode() ) {
		$paused_themes = wp_paused_themes();
		$paused_themes->delete( $old_theme->get_stylesheet() );
		$paused_themes->delete( $old_theme->get_template() );
	}

	update_option( 'template', $template );
	update_option( 'stylesheet', $stylesheet );

	if ( count( $wp_theme_directories ) > 1 ) {
		update_option( 'template_root', get_raw_theme_root( $template, true ) );
		update_option( 'stylesheet_root', get_raw_theme_root( $stylesheet, true ) );
	} else {
		delete_option( 'template_root' );
		delete_option( 'stylesheet_root' );
	}

	$new_name = $new_theme->get( 'Name' );

	update_option( 'current_theme', $new_name );

	// Migrate from the old mods_{name} option to theme_mods_{slug}.
	if ( is_admin() && false === get_option( 'theme_mods_' . $stylesheet ) ) {
		$default_theme_mods = (array) get_option( 'mods_' . $new_name );
		if ( ! empty( $nav_menu_locations ) && empty( $default_theme_mods['nav_menu_locations'] ) ) {
			$default_theme_mods['nav_menu_locations'] = $nav_menu_locations;
		}
		add_option( "theme_mods_$stylesheet", $default_theme_mods );
	} else {
		/*
		 * Since retrieve_widgets() is called when initializing a theme in the Customizer,
		 * we need to remove the theme mods to avoid overwriting changes made via
		 * the Customizer when accessing wp-admin/widgets.php.
		 */
		if ( 'wp_ajax_customize_save' === current_action() ) {
			remove_theme_mod( 'sidebars_widgets' );
		}
	}

	update_option( 'theme_switched', $old_theme->get_stylesheet() );

	/**
	 * Fires after the theme is switched.
	 *
	 * @since 1.5.0
	 * @since 4.5.0 Introduced the `$old_theme` parameter.
	 *
	 * @param string   $new_name  Name of the new theme.
	 * @param WP_Theme $new_theme WP_Theme instance of the new theme.
	 * @param WP_Theme $old_theme WP_Theme instance of the old theme.
	 */
	do_action( 'switch_theme', $new_name, $new_theme, $old_theme );
}

/**
 * Checks that the active theme has the required files.
 *
 * Standalone themes need to have a `templates/index.html` or `index.php` template file.
 * Child themes need to have a `Template` header in the `style.css` stylesheet.
 *
 * Does not initially check the default theme, which is the fallback and should always exist.
 * But if it doesn't exist, it'll fall back to the latest core default theme that does exist.
 * Will switch theme to the fallback theme if active theme does not validate.
 *
 * You can use the {@see 'validate_current_theme'} filter to return false to disable
 * this functionality.
 *
 * @since 1.5.0
 *
 * @see WP_DEFAULT_THEME
 *
 * @return bool
 */
function validate_current_theme() {
	/**
	 * Filters whether to validate the active theme.
	 *
	 * @since 2.7.0
	 *
	 * @param bool $validate Whether to validate the active theme. Default true.
	 */
	if ( wp_installing() || ! apply_filters( 'validate_current_theme', true ) ) {
		return true;
	}

	if ( ! file_exists( get_template_directory() . '/index.php' ) ) {
		// Invalid.
	} elseif ( ! file_exists( get_template_directory() . '/style.css' ) ) {
		// Invalid.
	} elseif ( is_child_theme() && ! file_exists( get_stylesheet_directory() . '/style.css' ) ) {
		// Invalid.
	} else {
		// Valid.
		return true;
	}

	$default = wp_get_theme( WP_DEFAULT_THEME );
	if ( $default->exists() ) {
		switch_theme( WP_DEFAULT_THEME );
		return false;
	}

	/**
	 * If we're in an invalid state but WP_DEFAULT_THEME doesn't exist,
	 * switch to the latest core default theme that's installed.
	 *
	 * If it turns out that this latest core default theme is our current
	 * theme, then there's nothing we can do about that, so we have to bail,
	 * rather than going into an infinite loop. (This is why there are
	 * checks against WP_DEFAULT_THEME above, also.) We also can't do anything
	 * if it turns out there is no default theme installed. (That's `false`.)
	 */
	$default = WP_Theme::get_core_default_theme();
	if ( false === $default || get_stylesheet() == $default->get_stylesheet() ) {
		return true;
	}

	switch_theme( $default->get_stylesheet() );
	return false;
}

/**
 * Validates the theme requirements for WordPress version and PHP version.
 *
 * Uses the information from `Requires at least` and `Requires PHP` headers
 * defined in the theme's `style.css` file.
 *
 * @since 5.5.0
 * @since 5.8.0 Removed support for using `readme.txt` as a fallback.
 *
 * @param string $stylesheet Directory name for the theme.
 * @return true|WP_Error True if requirements are met, WP_Error on failure.
 */
function validate_theme_requirements( $stylesheet ) {
	$theme = wp_get_theme( $stylesheet );

	$requirements = array(
		'requires'     => ! empty( $theme->get( 'RequiresWP' ) ) ? $theme->get( 'RequiresWP' ) : '',
		'requires_php' => ! empty( $theme->get( 'RequiresPHP' ) ) ? $theme->get( 'RequiresPHP' ) : '',
	);

	$compatible_wp  = is_wp_version_compatible( $requirements['requires'] );
	$compatible_php = is_php_version_compatible( $requirements['requires_php'] );

	if ( ! $compatible_wp && ! $compatible_php ) {
		return new WP_Error(
			'theme_wp_php_incompatible',
			sprintf(
				/* translators: %s: Theme name. */
				_x( '<strong>Error:</strong> Current ClassicPress and PHP versions do not meet minimum requirements for %s.', 'theme' ),
				$theme->display( 'Name' )
			)
		);
	} elseif ( ! $compatible_php ) {
		return new WP_Error(
			'theme_php_incompatible',
			sprintf(
				/* translators: %s: Theme name. */
				_x( '<strong>Error:</strong> Current PHP version does not meet minimum requirements for %s.', 'theme' ),
				$theme->display( 'Name' )
			)
		);
	} elseif ( ! $compatible_wp ) {
		return new WP_Error(
			'theme_wp_incompatible',
			sprintf(
				/* translators: %s: Theme name. */
				_x( '<strong>Error:</strong> Current ClassicPress version does not meet minimum requirements for %s.', 'theme' ),
				$theme->display( 'Name' )
			)
		);
	}

	return true;
}

/**
 * Retrieves all theme modifications.
 *
 * @since 3.1.0
 * @since 5.9.0 The return value is always an array.
 *
 * @return array Theme modifications.
 */
function get_theme_mods() {
	$theme_slug = get_option( 'stylesheet' );
	$mods       = get_option( "theme_mods_$theme_slug" );

	if ( false === $mods ) {
		$theme_name = get_option( 'current_theme' );
		if ( false === $theme_name ) {
			$theme_name = wp_get_theme()->get( 'Name' );
		}

		$mods = get_option( "mods_$theme_name" ); // Deprecated location.
		if ( is_admin() && false !== $mods ) {
			update_option( "theme_mods_$theme_slug", $mods );
			delete_option( "mods_$theme_name" );
		}
	}

	if ( ! is_array( $mods ) ) {
		$mods = array();
	}

	return $mods;
}

/**
 * Retrieves theme modification value for the active theme.
 *
 * If the modification name does not exist and `$default_value` is a string, then the
 * default will be passed through the {@link https://www.php.net/sprintf sprintf()}
 * PHP function with the template directory URI as the first value and the
 * stylesheet directory URI as the second value.
 *
 * @since 2.1.0
 *
 * @param string $name          Theme modification name.
 * @param mixed  $default_value Optional. Theme modification default value. Default false.
 * @return mixed Theme modification value.
 */
function get_theme_mod( $name, $default_value = false ) {
	$mods = get_theme_mods();

	if ( isset( $mods[ $name ] ) ) {
		/**
		 * Filters the theme modification, or 'theme_mod', value.
		 *
		 * The dynamic portion of the hook name, `$name`, refers to the key name
		 * of the modification array. For example, 'header_textcolor', 'header_image',
		 * and so on depending on the theme options.
		 *
		 * @since 2.2.0
		 *
		 * @param mixed $current_mod The value of the active theme modification.
		 */
		return apply_filters( "theme_mod_{$name}", $mods[ $name ] );
	}

	if ( is_string( $default_value ) ) {
		// Only run the replacement if an sprintf() string format pattern was found.
		if ( preg_match( '#(?<!%)%(?:\d+\$?)?s#', $default_value ) ) {
			// Remove a single trailing percent sign.
			$default_value = preg_replace( '#(?<!%)%$#', '', $default_value );
			$default_value = sprintf( $default_value, get_template_directory_uri(), get_stylesheet_directory_uri() );
		}
	}

	/** This filter is documented in wp-includes/theme.php */
	return apply_filters( "theme_mod_{$name}", $default_value );
}

/**
 * Updates theme modification value for the active theme.
 *
 * @since 2.1.0
 * @since 5.6.0 A return value was added.
 *
 * @param string $name  Theme modification name.
 * @param mixed  $value Theme modification value.
 * @return bool True if the value was updated, false otherwise.
 */
function set_theme_mod( $name, $value ) {
	$mods      = get_theme_mods();
	$old_value = isset( $mods[ $name ] ) ? $mods[ $name ] : false;

	/**
	 * Filters the theme modification, or 'theme_mod', value on save.
	 *
	 * The dynamic portion of the hook name, `$name`, refers to the key name
	 * of the modification array. For example, 'header_textcolor', 'header_image',
	 * and so on depending on the theme options.
	 *
	 * @since 3.9.0
	 *
	 * @param mixed $value     The new value of the theme modification.
	 * @param mixed $old_value The current value of the theme modification.
	 */
	$mods[ $name ] = apply_filters( "pre_set_theme_mod_{$name}", $value, $old_value );

	$theme = get_option( 'stylesheet' );

	return update_option( "theme_mods_$theme", $mods );
}

/**
 * Removes theme modification name from active theme list.
 *
 * If removing the name also removes all elements, then the entire option
 * will be removed.
 *
 * @since 2.1.0
 *
 * @param string $name Theme modification name.
 */
function remove_theme_mod( $name ) {
	$mods = get_theme_mods();

	if ( ! isset( $mods[ $name ] ) ) {
		return;
	}

	unset( $mods[ $name ] );

	if ( empty( $mods ) ) {
		remove_theme_mods();
		return;
	}

	$theme = get_option( 'stylesheet' );

	update_option( "theme_mods_$theme", $mods );
}

/**
 * Removes theme modifications option for the active theme.
 *
 * @since 2.1.0
 */
function remove_theme_mods() {
	delete_option( 'theme_mods_' . get_option( 'stylesheet' ) );

	// Old style.
	$theme_name = get_option( 'current_theme' );
	if ( false === $theme_name ) {
		$theme_name = wp_get_theme()->get( 'Name' );
	}

	delete_option( 'mods_' . $theme_name );
}

/**
 * Retrieves the custom header text color in 3- or 6-digit hexadecimal form.
 *
 * @since 2.1.0
 *
 * @return string Header text color in 3- or 6-digit hexadecimal form (minus the hash symbol).
 */
function get_header_textcolor() {
	return get_theme_mod( 'header_textcolor', get_theme_support( 'custom-header', 'default-text-color' ) );
}

/**
 * Displays the custom header text color in 3- or 6-digit hexadecimal form (minus the hash symbol).
 *
 * @since 2.1.0
 */
function header_textcolor() {
	echo get_header_textcolor();
}

/**
 * Whether to display the header text.
 *
 * @since 3.4.0
 *
 * @return bool
 */
function display_header_text() {
	if ( ! current_theme_supports( 'custom-header', 'header-text' ) ) {
		return false;
	}

	$text_color = get_theme_mod( 'header_textcolor', get_theme_support( 'custom-header', 'default-text-color' ) );
	return 'blank' !== $text_color;
}

/**
 * Checks whether a header image is set or not.
 *
 * @since 4.2.0
 *
 * @see get_header_image()
 *
 * @return bool Whether a header image is set or not.
 */
function has_header_image() {
	return (bool) get_header_image();
}

/**
 * Retrieves header image for custom header.
 *
 * @since 2.1.0
 *
 * @return string|false
 */
function get_header_image() {
	$url = get_theme_mod( 'header_image', get_theme_support( 'custom-header', 'default-image' ) );

	if ( 'remove-header' === $url ) {
		return false;
	}

	if ( is_random_header_image() ) {
		$url = get_random_header_image();
	}

	/**
	 * Filters the header image URL.
	 *
	 * @since 6.1.0
	 *
	 * @param string $url Header image URL.
	 */
	$url = apply_filters( 'get_header_image', $url );

	if ( ! is_string( $url ) ) {
		return false;
	}

	$url = trim( $url );
	return sanitize_url( set_url_scheme( $url ) );
}

/**
 * Creates image tag markup for a custom header image.
 *
 * @since 4.4.0
 *
 * @param array $attr Optional. Additional attributes for the image tag. Can be used
 *                              to override the default attributes. Default empty.
 * @return string HTML image element markup or empty string on failure.
 */
function get_header_image_tag( $attr = array() ) {
	$header      = get_custom_header();
	$header->url = get_header_image();

	if ( ! $header->url ) {
		return '';
	}

	$width  = absint( $header->width );
	$height = absint( $header->height );
	$alt    = '';

	// Use alternative text assigned to the image, if available. Otherwise, leave it empty.
	if ( ! empty( $header->attachment_id ) ) {
		$image_alt = get_post_meta( $header->attachment_id, '_wp_attachment_image_alt', true );

		if ( is_string( $image_alt ) ) {
			$alt = $image_alt;
		}
	}

	$attr = wp_parse_args(
		$attr,
		array(
			'src'    => $header->url,
			'width'  => $width,
			'height' => $height,
			'alt'    => $alt,
			'decoding' => 'async',
		)
	);

	// Generate 'srcset' and 'sizes' if not already present.
	if ( empty( $attr['srcset'] ) && ! empty( $header->attachment_id ) ) {
		$image_meta = get_post_meta( $header->attachment_id, '_wp_attachment_metadata', true );
		$size_array = array( $width, $height );

		if ( is_array( $image_meta ) ) {
			$srcset = wp_calculate_image_srcset( $size_array, $header->url, $image_meta, $header->attachment_id );

			if ( ! empty( $attr['sizes'] ) ) {
				$sizes = $attr['sizes'];
			} else {
				$sizes = wp_calculate_image_sizes( $size_array, $header->url, $image_meta, $header->attachment_id );
			}

			if ( $srcset && $sizes ) {
				$attr['srcset'] = $srcset;
				$attr['sizes']  = $sizes;
			}
		}
	}

	$attr = array_merge(
		$attr,
		wp_get_loading_optimization_attributes( 'img', $attr, 'get_header_image_tag' )
	);

	/*
	 * If the default value of `lazy` for the `loading` attribute is overridden
	 * to omit the attribute for this image, ensure it is not included.
	 */
	if ( isset( $attr['loading'] ) && ! $attr['loading'] ) {
		unset( $attr['loading'] );
	}

	// If the `fetchpriority` attribute is overridden and set to false or an empty string.
	if ( isset( $attr['fetchpriority'] ) && ! $attr['fetchpriority'] ) {
		unset( $attr['fetchpriority'] );
	}

	// If the `decoding` attribute is overridden and set to false or an empty string.
	if ( isset( $attr['decoding'] ) && ! $attr['decoding'] ) {
		unset( $attr['decoding'] );
	}

	/**
	 * Filters the list of header image attributes.
	 *
	 * @since 5.9.0
	 *
	 * @param array  $attr   Array of the attributes for the image tag.
	 * @param object $header The custom header object returned by 'get_custom_header()'.
	 */
	$attr = apply_filters( 'get_header_image_tag_attributes', $attr, $header );

	$attr = array_map( 'esc_attr', $attr );
	$html = '<img';

	foreach ( $attr as $name => $value ) {
		$html .= ' ' . $name . '="' . $value . '"';
	}

	$html .= '>';

	/**
	 * Filters the markup of header images.
	 *
	 * @since 4.4.0
	 *
	 * @param string $html   The HTML image tag markup being filtered.
	 * @param object $header The custom header object returned by 'get_custom_header()'.
	 * @param array  $attr   Array of the attributes for the image tag.
	 */
	return apply_filters( 'get_header_image_tag', $html, $header, $attr );
}

/**
 * Displays the image markup for a custom header image.
 *
 * @since 4.4.0
 *
 * @param array $attr Optional. Attributes for the image markup. Default empty.
 */
function the_header_image_tag( $attr = array() ) {
	echo get_header_image_tag( $attr );
}

/**
 * Gets random header image data from registered images in theme.
 *
 * @since 3.4.0
 *
 * @access private
 *
 * @global array $_wp_default_headers
 *
 * @return object
 */
function _get_random_header_data() {
	global $_wp_default_headers;
	static $_wp_random_header = null;

	if ( empty( $_wp_random_header ) ) {
		$header_image_mod = get_theme_mod( 'header_image', '' );
		$headers          = array();

		if ( 'random-uploaded-image' === $header_image_mod ) {
			$headers = get_uploaded_header_images();
		} elseif ( ! empty( $_wp_default_headers ) ) {
			if ( 'random-default-image' === $header_image_mod ) {
				$headers = $_wp_default_headers;
			} else {
				if ( current_theme_supports( 'custom-header', 'random-default' ) ) {
					$headers = $_wp_default_headers;
				}
			}
		}

		if ( empty( $headers ) ) {
			return new stdClass();
		}

		$_wp_random_header = (object) $headers[ array_rand( $headers ) ];

		$_wp_random_header->url = sprintf(
			$_wp_random_header->url,
			get_template_directory_uri(),
			get_stylesheet_directory_uri()
		);

		$_wp_random_header->thumbnail_url = sprintf(
			$_wp_random_header->thumbnail_url,
			get_template_directory_uri(),
			get_stylesheet_directory_uri()
		);
	}

	return $_wp_random_header;
}

/**
 * Gets random header image URL from registered images in theme.
 *
 * @since 3.2.0
 *
 * @return string Path to header image.
 */
function get_random_header_image() {
	$random_image = _get_random_header_data();

	if ( empty( $random_image->url ) ) {
		return '';
	}

	return $random_image->url;
}

/**
 * Checks if random header image is in use.
 *
 * Always true if user expressly chooses the option in Appearance > Header.
 * Also true if theme has multiple header images registered, no specific header image
 * is chosen, and theme turns on random headers with add_theme_support().
 *
 * @since 3.2.0
 *
 * @param string $type The random pool to use. Possible values include 'any',
 *                     'default', 'uploaded'. Default 'any'.
 * @return bool
 */
function is_random_header_image( $type = 'any' ) {
	$header_image_mod = get_theme_mod( 'header_image', get_theme_support( 'custom-header', 'default-image' ) );

	if ( 'any' === $type ) {
		if ( 'random-default-image' === $header_image_mod
			|| 'random-uploaded-image' === $header_image_mod
			|| ( '' !== get_random_header_image() && empty( $header_image_mod ) )
		) {
			return true;
		}
	} else {
		if ( "random-$type-image" === $header_image_mod ) {
			return true;
		} elseif ( 'default' === $type && empty( $header_image_mod ) && '' !== get_random_header_image() ) {
			return true;
		}
	}

	return false;
}

/**
 * Displays header image URL.
 *
 * @since 2.1.0
 */
function header_image() {
	$image = get_header_image();

	if ( $image ) {
		echo esc_url( $image );
	}
}

/**
 * Gets the header images uploaded for the active theme.
 *
 * @since 3.2.0
 *
 * @return array
 */
function get_uploaded_header_images() {
	$header_images = array();

	// @todo Caching.
	$headers = get_posts(
		array(
			'post_type'  => 'attachment',
			'meta_key'   => '_wp_attachment_is_custom_header',
			'meta_value' => get_option( 'stylesheet' ),
			'orderby'    => 'none',
			'nopaging'   => true,
		)
	);

	if ( empty( $headers ) ) {
		return array();
	}

	foreach ( (array) $headers as $header ) {
		$url          = sanitize_url( wp_get_attachment_url( $header->ID ) );
		$header_data  = wp_get_attachment_metadata( $header->ID );
		$header_index = $header->ID;

		$header_images[ $header_index ]                  = array();
		$header_images[ $header_index ]['attachment_id'] = $header->ID;
		$header_images[ $header_index ]['url']           = $url;
		$header_images[ $header_index ]['thumbnail_url'] = $url;
		$header_images[ $header_index ]['alt_text']      = get_post_meta( $header->ID, '_wp_attachment_image_alt', true );

		if ( isset( $header_data['attachment_parent'] ) ) {
			$header_images[ $header_index ]['attachment_parent'] = $header_data['attachment_parent'];
		} else {
			$header_images[ $header_index ]['attachment_parent'] = '';
		}

		if ( isset( $header_data['width'] ) ) {
			$header_images[ $header_index ]['width'] = $header_data['width'];
		}
		if ( isset( $header_data['height'] ) ) {
			$header_images[ $header_index ]['height'] = $header_data['height'];
		}
	}

	return $header_images;
}

/**
 * Gets the header image data.
 *
 * @since 3.4.0
 *
 * @global array $_wp_default_headers
 *
 * @return object
 */
function get_custom_header() {
	global $_wp_default_headers;

	if ( is_random_header_image() ) {
		$data = _get_random_header_data();
	} else {
		$data = get_theme_mod( 'header_image_data' );
		if ( ! $data && current_theme_supports( 'custom-header', 'default-image' ) ) {
			$directory_args        = array( get_template_directory_uri(), get_stylesheet_directory_uri() );
			$data                  = array();
			$data['url']           = vsprintf( get_theme_support( 'custom-header', 'default-image' ), $directory_args );
			$data['thumbnail_url'] = $data['url'];
			if ( ! empty( $_wp_default_headers ) ) {
				foreach ( (array) $_wp_default_headers as $default_header ) {
					$url = vsprintf( $default_header['url'], $directory_args );
					if ( $data['url'] == $url ) {
						$data                  = $default_header;
						$data['url']           = $url;
						$data['thumbnail_url'] = vsprintf( $data['thumbnail_url'], $directory_args );
						break;
					}
				}
			}
		}
	}

	$default = array(
		'url'           => '',
		'thumbnail_url' => '',
		'width'         => get_theme_support( 'custom-header', 'width' ),
		'height'        => get_theme_support( 'custom-header', 'height' ),
		'video'         => get_theme_support( 'custom-header', 'video' ),
	);
	return (object) wp_parse_args( $data, $default );
}

/**
 * Registers a selection of default headers to be displayed by the custom header admin UI.
 *
 * @since 3.0.0
 *
 * @global array $_wp_default_headers
 *
 * @param array $headers Array of headers keyed by a string ID. The IDs point to arrays
 *                       containing 'url', 'thumbnail_url', and 'description' keys.
 */
function register_default_headers( $headers ) {
	global $_wp_default_headers;

	$_wp_default_headers = array_merge( (array) $_wp_default_headers, (array) $headers );
}

/**
 * Unregisters default headers.
 *
 * This function must be called after register_default_headers() has already added the
 * header you want to remove.
 *
 * @see register_default_headers()
 * @since 3.0.0
 *
 * @global array $_wp_default_headers
 *
 * @param string|array $header The header string id (key of array) to remove, or an array thereof.
 * @return bool|void A single header returns true on success, false on failure.
 *                   There is currently no return value for multiple headers.
 */
function unregister_default_headers( $header ) {
	global $_wp_default_headers;

	if ( is_array( $header ) ) {
		array_map( 'unregister_default_headers', $header );
	} elseif ( isset( $_wp_default_headers[ $header ] ) ) {
		unset( $_wp_default_headers[ $header ] );
		return true;
	} else {
		return false;
	}
}

/**
 * Checks whether a header video is set or not.
 *
 * @since 4.7.0
 *
 * @see get_header_video_url()
 *
 * @return bool Whether a header video is set or not.
 */
function has_header_video() {
	return (bool) get_header_video_url();
}

/**
 * Retrieves header video URL for custom header.
 *
 * Uses a local video if present, or falls back to an external video.
 *
 * @since 4.7.0
 *
 * @return string|false Header video URL or false if there is no video.
 */
function get_header_video_url() {
	$id = absint( get_theme_mod( 'header_video' ) );

	if ( $id ) {
		// Get the file URL from the attachment ID.
		$url = wp_get_attachment_url( $id );
	} else {
		$url = get_theme_mod( 'external_header_video' );
	}

	/**
	 * Filters the header video URL.
	 *
	 * @since 4.7.3
	 *
	 * @param string $url Header video URL, if available.
	 */
	$url = apply_filters( 'get_header_video_url', $url );

	if ( ! $id && ! $url ) {
		return false;
	}

	return sanitize_url( set_url_scheme( $url ) );
}

/**
 * Displays header video URL.
 *
 * @since 4.7.0
 */
function the_header_video_url() {
	$video = get_header_video_url();

	if ( $video ) {
		echo esc_url( $video );
	}
}

/**
 * Retrieves header video settings.
 *
 * @since 4.7.0
 *
 * @return array
 */
function get_header_video_settings() {
	$header     = get_custom_header();
	$video_url  = get_header_video_url();
	$video_type = wp_check_filetype( $video_url, wp_get_mime_types() );

	$settings = array(
		'mimeType'  => '',
		'posterUrl' => get_header_image(),
		'videoUrl'  => $video_url,
		'width'     => absint( $header->width ),
		'height'    => absint( $header->height ),
		'minWidth'  => 900,
		'minHeight' => 500,
		'l10n'      => array(
			'pause'      => __( 'Pause' ),
			'play'       => __( 'Play' ),
			'pauseSpeak' => __( 'Video is paused.' ),
			'playSpeak'  => __( 'Video is playing.' ),
		),
	);

	if ( preg_match( '#^https?://(?:www\.)?(?:youtube\.com/watch|youtu\.be/)#', $video_url ) ) {
		$settings['mimeType'] = 'video/x-youtube';
	} elseif ( ! empty( $video_type['type'] ) ) {
		$settings['mimeType'] = $video_type['type'];
	}

	/**
	 * Filters header video settings.
	 *
	 * @since 4.7.0
	 *
	 * @param array $settings An array of header video settings.
	 */
	return apply_filters( 'header_video_settings', $settings );
}

/**
 * Checks whether a custom header is set or not.
 *
 * @since 4.7.0
 *
 * @return bool True if a custom header is set. False if not.
 */
function has_custom_header() {
	if ( has_header_image() || ( has_header_video() && is_header_video_active() ) ) {
		return true;
	}

	return false;
}

/**
 * Checks whether the custom header video is eligible to show on the current page.
 *
 * @since 4.7.0
 *
 * @return bool True if the custom header video should be shown. False if not.
 */
function is_header_video_active() {
	if ( ! get_theme_support( 'custom-header', 'video' ) ) {
		return false;
	}

	$video_active_cb = get_theme_support( 'custom-header', 'video-active-callback' );

	if ( empty( $video_active_cb ) || ! is_callable( $video_active_cb ) ) {
		$show_video = true;
	} else {
		$show_video = call_user_func( $video_active_cb );
	}

	/**
	 * Filters whether the custom header video is eligible to show on the current page.
	 *
	 * @since 4.7.0
	 *
	 * @param bool $show_video Whether the custom header video should be shown. Returns the value
	 *                         of the theme setting for the `custom-header`'s `video-active-callback`.
	 *                         If no callback is set, the default value is that of `is_front_page()`.
	 */
	return apply_filters( 'is_header_video_active', $show_video );
}

/**
 * Retrieves the markup for a custom header.
 *
 * The container div will always be returned in the Customizer preview.
 *
 * @since 4.7.0
 *
 * @return string The markup for a custom header on success.
 */
function get_custom_header_markup() {
	if ( ! has_custom_header() && ! is_customize_preview() ) {
		return '';
	}

	return sprintf(
		'<div id="wp-custom-header" class="wp-custom-header">%s</div>',
		get_header_image_tag()
	);
}

/**
 * Prints the markup for a custom header.
 *
 * A container div will always be printed in the Customizer preview.
 *
 * @since 4.7.0
 */
function the_custom_header_markup() {
	$custom_header = get_custom_header_markup();
	if ( empty( $custom_header ) ) {
		return;
	}

	echo $custom_header;

	if ( is_header_video_active() && ( has_header_video() || is_customize_preview() ) ) {
		wp_enqueue_script( 'wp-custom-header' );
		wp_localize_script( 'wp-custom-header', '_wpCustomHeaderSettings', get_header_video_settings() );
	}
}

/**
 * Retrieves background image for custom background.
 *
 * @since 3.0.0
 *
 * @return string
 */
function get_background_image() {
	return get_theme_mod( 'background_image', get_theme_support( 'custom-background', 'default-image' ) );
}

/**
 * Displays background image path.
 *
 * @since 3.0.0
 */
function background_image() {
	echo get_background_image();
}

/**
 * Retrieves value for custom background color.
 *
 * @since 3.0.0
 *
 * @return string
 */
function get_background_color() {
	return get_theme_mod( 'background_color', get_theme_support( 'custom-background', 'default-color' ) );
}

/**
 * Displays background color value.
 *
 * @since 3.0.0
 */
function background_color() {
	echo get_background_color();
}

/**
 * Default custom background callback.
 *
 * @since 3.0.0
 */
function _custom_background_cb() {
	// $background is the saved custom image, or the default image.
	$background = set_url_scheme( get_background_image() );

	// $color is the saved custom color.
	// A default has to be specified in style.css. It will not be printed here.
	$color = get_background_color();

	if ( get_theme_support( 'custom-background', 'default-color' ) === $color ) {
		$color = false;
	}

	if ( ! $background && ! $color ) {
		if ( is_customize_preview() ) {
			print( '<style id="custom-background-css"></style>' );
		}
		return;
	}

	$style = $color ? "background-color: #$color;" : '';

	if ( $background ) {
		$image = ' background-image: url("' . sanitize_url( $background ) . '");';

		// Background Position.
		$position_x = get_theme_mod( 'background_position_x', get_theme_support( 'custom-background', 'default-position-x' ) );
		$position_y = get_theme_mod( 'background_position_y', get_theme_support( 'custom-background', 'default-position-y' ) );

		if ( ! in_array( $position_x, array( 'left', 'center', 'right' ), true ) ) {
			$position_x = 'left';
		}

		if ( ! in_array( $position_y, array( 'top', 'center', 'bottom' ), true ) ) {
			$position_y = 'top';
		}

		$position = " background-position: $position_x $position_y;";

		// Background Size.
		$size = get_theme_mod( 'background_size', get_theme_support( 'custom-background', 'default-size' ) );

		if ( ! in_array( $size, array( 'auto', 'contain', 'cover' ), true ) ) {
			$size = 'auto';
		}

		$size = " background-size: $size;";

		// Background Repeat.
		$repeat = get_theme_mod( 'background_repeat', get_theme_support( 'custom-background', 'default-repeat' ) );

		if ( ! in_array( $repeat, array( 'repeat-x', 'repeat-y', 'repeat', 'no-repeat' ), true ) ) {
			$repeat = 'repeat';
		}

		$repeat = " background-repeat: $repeat;";

		// Background Scroll.
		$attachment = get_theme_mod( 'background_attachment', get_theme_support( 'custom-background', 'default-attachment' ) );

		if ( 'fixed' !== $attachment ) {
			$attachment = 'scroll';
		}

		$attachment = " background-attachment: $attachment;";

		$style .= $image . $position . $size . $repeat . $attachment;
	}
	?>
<style id="custom-background-css">
body.custom-background { <?php echo trim( $style ); ?> }
</style>
	<?php
}

/**
 * Renders the Custom CSS style element.
 *
 * @since 4.7.0
 */
function wp_custom_css_cb() {
	$styles = wp_get_custom_css();
	if ( $styles || is_customize_preview() ) :
		?>
		<style id="wp-custom-css">
			<?php
			// Note that esc_html() cannot be used because `div &gt; span` is not interpreted properly.
			echo strip_tags( $styles );
			?>
		</style>
		<?php
	endif;
}

/**
 * Fetches the `custom_css` post for a given theme.
 *
 * @since 4.7.0
 *
 * @param string $stylesheet Optional. A theme object stylesheet name. Defaults to the active theme.
 * @return WP_Post|null The custom_css post or null if none exists.
 */
function wp_get_custom_css_post( $stylesheet = '' ) {
	if ( empty( $stylesheet ) ) {
		$stylesheet = get_stylesheet();
	}

	$custom_css_query_vars = array(
		'post_type'              => 'custom_css',
		'post_status'            => get_post_stati(),
		'name'                   => sanitize_title( $stylesheet ),
		'posts_per_page'         => 1,
		'no_found_rows'          => true,
		'cache_results'          => true,
		'update_post_meta_cache' => false,
		'update_post_term_cache' => false,
		'lazy_load_term_meta'    => false,
	);

	$post = null;
	if ( get_stylesheet() === $stylesheet ) {
		$post_id = get_theme_mod( 'custom_css_post_id' );

		if ( $post_id > 0 && get_post( $post_id ) ) {
			$post = get_post( $post_id );
		}

		// `-1` indicates no post exists; no query necessary.
		if ( ! $post && -1 !== $post_id ) {
			$query = new WP_Query( $custom_css_query_vars );
			$post  = $query->post;
			/*
			 * Cache the lookup. See wp_update_custom_css_post().
			 * @todo This should get cleared if a custom_css post is added/removed.
			 */
			set_theme_mod( 'custom_css_post_id', $post ? $post->ID : -1 );
		}
	} else {
		$query = new WP_Query( $custom_css_query_vars );
		$post  = $query->post;
	}

	return $post;
}

/**
 * Fetches the saved Custom CSS content for rendering.
 *
 * @since 4.7.0
 *
 * @param string $stylesheet Optional. A theme object stylesheet name. Defaults to the active theme.
 * @return string The Custom CSS Post content.
 */
function wp_get_custom_css( $stylesheet = '' ) {
	$css = '';

	if ( empty( $stylesheet ) ) {
		$stylesheet = get_stylesheet();
	}

	$post = wp_get_custom_css_post( $stylesheet );
	if ( $post ) {
		$css = $post->post_content;
	}

	/**
	 * Filters the custom CSS output into the head element.
	 *
	 * @since 4.7.0
	 *
	 * @param string $css        CSS pulled in from the Custom CSS post type.
	 * @param string $stylesheet The theme stylesheet name.
	 */
	$css = apply_filters( 'wp_get_custom_css', $css, $stylesheet );

	return $css;
}

/**
 * Updates the `custom_css` post for a given theme.
 *
 * Inserts a `custom_css` post when one doesn't yet exist.
 *
 * @since 4.7.0
 *
 * @param string $css CSS, stored in `post_content`.
 * @param array  $args {
 *     Args.
 *
 *     @type string $preprocessed Optional. Pre-processed CSS, stored in `post_content_filtered`.
 *                                Normally empty string.
 *     @type string $stylesheet   Optional. Stylesheet (child theme) to update.
 *                                Defaults to active theme/stylesheet.
 * }
 * @return WP_Post|WP_Error Post on success, error on failure.
 */
function wp_update_custom_css_post( $css, $args = array() ) {
	$args = wp_parse_args(
		$args,
		array(
			'preprocessed' => '',
			'stylesheet'   => get_stylesheet(),
		)
	);

	$data = array(
		'css'          => $css,
		'preprocessed' => $args['preprocessed'],
	);

	/**
	 * Filters the `css` (`post_content`) and `preprocessed` (`post_content_filtered`) args
	 * for a `custom_css` post being updated.
	 *
	 * This filter can be used by plugin that offer CSS pre-processors, to store the original
	 * pre-processed CSS in `post_content_filtered` and then store processed CSS in `post_content`.
	 * When used in this way, the `post_content_filtered` should be supplied as the setting value
	 * instead of `post_content` via a the `customize_value_custom_css` filter, for example:
	 *
	 * <code>
	 * add_filter( 'customize_value_custom_css', function( $value, $setting ) {
	 *     $post = wp_get_custom_css_post( $setting->stylesheet );
	 *     if ( $post && ! empty( $post->post_content_filtered ) ) {
	 *         $css = $post->post_content_filtered;
	 *     }
	 *     return $css;
	 * }, 10, 2 );
	 * </code>
	 *
	 * @since 4.7.0
	 * @param array $data {
	 *     Custom CSS data.
	 *
	 *     @type string $css          CSS stored in `post_content`.
	 *     @type string $preprocessed Pre-processed CSS stored in `post_content_filtered`.
	 *                                Normally empty string.
	 * }
	 * @param array $args {
	 *     The args passed into `wp_update_custom_css_post()` merged with defaults.
	 *
	 *     @type string $css          The original CSS passed in to be updated.
	 *     @type string $preprocessed The original preprocessed CSS passed in to be updated.
	 *     @type string $stylesheet   The stylesheet (theme) being updated.
	 * }
	 */
	$data = apply_filters( 'update_custom_css_data', $data, array_merge( $args, compact( 'css' ) ) );

	$post_data = array(
		'post_title'            => $args['stylesheet'],
		'post_name'             => sanitize_title( $args['stylesheet'] ),
		'post_type'             => 'custom_css',
		'post_status'           => 'publish',
		'post_content'          => $data['css'],
		'post_content_filtered' => $data['preprocessed'],
	);

	// Update post if it already exists, otherwise create a new one.
	$post = wp_get_custom_css_post( $args['stylesheet'] );
	if ( $post ) {
		$post_data['ID'] = $post->ID;
		$r               = wp_update_post( wp_slash( $post_data ), true );
	} else {
		$r = wp_insert_post( wp_slash( $post_data ), true );

		if ( ! is_wp_error( $r ) ) {
			if ( get_stylesheet() === $args['stylesheet'] ) {
				set_theme_mod( 'custom_css_post_id', $r );
			}

			// Trigger creation of a revision. This should be removed once #30854 is resolved.
			$revisions = wp_get_latest_revision_id_and_total_count( $r );
			if ( ! is_wp_error( $revisions ) && 0 === $revisions['count'] ) {
				wp_save_post_revision( $r );
			}
		}
	}

	if ( is_wp_error( $r ) ) {
		return $r;
	}
	return get_post( $r );
}

/**
 * Adds callback for custom TinyMCE editor stylesheets.
 *
 * The parameter $stylesheet is the name of the stylesheet, relative to
 * the theme root. It also accepts an array of stylesheets.
 * It is optional and defaults to 'editor-style.css'.
 *
 * This function automatically adds another stylesheet with -rtl prefix, e.g. editor-style-rtl.css.
 * If that file doesn't exist, it is removed before adding the stylesheet(s) to TinyMCE.
 * If an array of stylesheets is passed to add_editor_style(),
 * RTL is only added for the first stylesheet.
 *
 * Since version 3.4 the TinyMCE body has .rtl CSS class.
 * It is a better option to use that class and add any RTL styles to the main stylesheet.
 *
 * @since 3.0.0
 *
 * @global array $editor_styles
 *
 * @param array|string $stylesheet Optional. Stylesheet name or array thereof, relative to theme root.
 *                                 Defaults to 'editor-style.css'
 */
function add_editor_style( $stylesheet = 'editor-style.css' ) {
	global $editor_styles;

	add_theme_support( 'editor-style' );

	$editor_styles = (array) $editor_styles;
	$stylesheet    = (array) $stylesheet;

	if ( is_rtl() ) {
		$rtl_stylesheet = str_replace( '.css', '-rtl.css', $stylesheet[0] );
		$stylesheet[]   = $rtl_stylesheet;
	}

	$editor_styles = array_merge( $editor_styles, $stylesheet );
}

/**
 * Removes all visual editor stylesheets.
 *
 * @since 3.1.0
 *
 * @global array $editor_styles
 *
 * @return bool True on success, false if there were no stylesheets to remove.
 */
function remove_editor_styles() {
	if ( ! current_theme_supports( 'editor-style' ) ) {
		return false;
	}
	_remove_theme_support( 'editor-style' );
	if ( is_admin() ) {
		$GLOBALS['editor_styles'] = array();
	}
	return true;
}

/**
 * Retrieves any registered editor stylesheet URLs.
 *
 * @since 4.0.0
 *
 * @global array $editor_styles Registered editor stylesheets
 *
 * @return string[] If registered, a list of editor stylesheet URLs.
 */
function get_editor_stylesheets() {
	$stylesheets = array();
	// Load editor_style.css if the active theme supports it.
	if ( ! empty( $GLOBALS['editor_styles'] ) && is_array( $GLOBALS['editor_styles'] ) ) {
		$editor_styles = $GLOBALS['editor_styles'];

		$editor_styles = array_unique( array_filter( $editor_styles ) );
		$style_uri     = get_stylesheet_directory_uri();
		$style_dir     = get_stylesheet_directory();

		// Support externally referenced styles (like, say, fonts).
		foreach ( $editor_styles as $key => $file ) {
			if ( preg_match( '~^(https?:)?//~', $file ) ) {
				$stylesheets[] = sanitize_url( $file );
				unset( $editor_styles[ $key ] );
			}
		}

		// Look in a parent theme first, that way child theme CSS overrides.
		if ( is_child_theme() ) {
			$template_uri = get_template_directory_uri();
			$template_dir = get_template_directory();

			foreach ( $editor_styles as $key => $file ) {
				if ( $file && file_exists( "$template_dir/$file" ) ) {
					$stylesheets[] = "$template_uri/$file";
				}
			}
		}

		foreach ( $editor_styles as $file ) {
			if ( $file && file_exists( "$style_dir/$file" ) ) {
				$stylesheets[] = "$style_uri/$file";
			}
		}
	}

	/**
	 * Filters the array of URLs of stylesheets applied to the editor.
	 *
	 * @since 4.3.0
	 *
	 * @param string[] $stylesheets Array of URLs of stylesheets to be applied to the editor.
	 */
	return apply_filters( 'editor_stylesheets', $stylesheets );
}

/**
 * Expands a theme's starter content configuration using core-provided data.
 *
 * @since 4.7.0
 *
 * @return array Array of starter content.
 */
function get_theme_starter_content() {
	$theme_support = get_theme_support( 'starter-content' );
	if ( is_array( $theme_support ) && ! empty( $theme_support[0] ) && is_array( $theme_support[0] ) ) {
		$config = $theme_support[0];
	} else {
		$config = array();
	}

	$core_content = array(
		'widgets'   => array(
			'text_business_info' => array(
				'text',
				array(
					'title'  => _x( 'Find Us', 'Theme starter content' ),
					'text'   => implode(
						'',
						array(
							'<strong>' . _x( 'Address', 'Theme starter content' ) . "</strong>\n",
							_x( '123 Main Street', 'Theme starter content' ) . "\n",
							_x( 'New York, NY 10001', 'Theme starter content' ) . "\n\n",
							'<strong>' . _x( 'Hours', 'Theme starter content' ) . "</strong>\n",
							_x( 'Monday&ndash;Friday: 9:00AM&ndash;5:00PM', 'Theme starter content' ) . "\n",
							_x( 'Saturday &amp; Sunday: 11:00AM&ndash;3:00PM', 'Theme starter content' ),
						)
					),
					'filter' => true,
					'visual' => true,
				),
			),
			'text_about'         => array(
				'text',
				array(
					'title'  => _x( 'About This Site', 'Theme starter content' ),
					'text'   => _x( 'This may be a good place to introduce yourself and your site or include some credits.', 'Theme starter content' ),
					'filter' => true,
					'visual' => true,
				),
			),
			'archives'           => array(
				'archives',
				array(
					'title' => _x( 'Archives', 'Theme starter content' ),
				),
			),
			'calendar'           => array(
				'calendar',
				array(
					'title' => _x( 'Calendar', 'Theme starter content' ),
				),
			),
			'categories'         => array(
				'categories',
				array(
					'title' => _x( 'Categories', 'Theme starter content' ),
				),
			),
			'meta'               => array(
				'meta',
				array(
					'title' => _x( 'Meta', 'Theme starter content' ),
				),
			),
			'recent-comments'    => array(
				'recent-comments',
				array(
					'title' => _x( 'Recent Comments', 'Theme starter content' ),
				),
			),
			'recent-posts'       => array(
				'recent-posts',
				array(
					'title' => _x( 'Recent Posts', 'Theme starter content' ),
				),
			),
			'search'             => array(
				'search',
				array(
					'title' => _x( 'Search', 'Theme starter content' ),
				),
			),
		),
		'nav_menus' => array(
			'link_home'       => array(
				'type'  => 'custom',
				'title' => _x( 'Home', 'Theme starter content' ),
				'url'   => home_url( '/' ),
			),
			'page_home'       => array( // Deprecated in favor of 'link_home'.
				'type'      => 'post_type',
				'object'    => 'page',
				'object_id' => '{{home}}',
			),
			'page_about'      => array(
				'type'      => 'post_type',
				'object'    => 'page',
				'object_id' => '{{about}}',
			),
			'page_blog'       => array(
				'type'      => 'post_type',
				'object'    => 'page',
				'object_id' => '{{blog}}',
			),
			'page_news'       => array(
				'type'      => 'post_type',
				'object'    => 'page',
				'object_id' => '{{news}}',
			),
			'page_contact'    => array(
				'type'      => 'post_type',
				'object'    => 'page',
				'object_id' => '{{contact}}',
			),

			'link_email'      => array(
				'title' => _x( 'Email', 'Theme starter content' ),
				'url'   => 'mailto:classicpress@example.com',
			),
			'link_facebook'   => array(
				'title' => _x( 'Facebook', 'Theme starter content' ),
				'url'   => 'https://www.facebook.com/wordpress',
			),
			'link_foursquare' => array(
				'title' => _x( 'Foursquare', 'Theme starter content' ),
				'url'   => 'https://foursquare.com/',
			),
			'link_github'     => array(
				'title' => _x( 'GitHub', 'Theme starter content' ),
				'url'   => 'https://github.com/wordpress/',
			),
			'link_instagram'  => array(
				'title' => _x( 'Instagram', 'Theme starter content' ),
				'url'   => 'https://www.instagram.com/explore/tags/wordcamp/',
			),
			'link_linkedin'   => array(
				'title' => _x( 'LinkedIn', 'Theme starter content' ),
				'url'   => 'https://www.linkedin.com/company/1089783',
			),
			'link_pinterest'  => array(
				'title' => _x( 'Pinterest', 'Theme starter content' ),
				'url'   => 'https://www.pinterest.com/',
			),
			'link_twitter'    => array(
				'title' => _x( 'Twitter', 'Theme starter content' ),
				'url'   => 'https://twitter.com/wordpress',
			),
			'link_yelp'       => array(
				'title' => _x( 'Yelp', 'Theme starter content' ),
				'url'   => 'https://www.yelp.com',
			),
			'link_youtube'    => array(
				'title' => _x( 'YouTube', 'Theme starter content' ),
				'url'   => 'https://www.youtube.com/channel/UCdof4Ju7amm1chz1gi1T2ZA',
			),
		),
		'posts'     => array(
			'home'             => array(
				'post_type'    => 'page',
				'post_title'   => _x( 'Home', 'Theme starter content' ),
				'post_content' => _x( 'Welcome to your site! This is your homepage, which is what most visitors will see when they come to your site for the first time.', 'Theme starter content' ),
			),
			'about'            => array(
				'post_type'    => 'page',
				'post_title'   => _x( 'About', 'Theme starter content' ),
				'post_content' => _x( 'You might be an artist who would like to introduce yourself and your work here or maybe you&rsquo;re a business with a mission to describe.', 'Theme starter content' ),
			),
			'contact'          => array(
				'post_type'    => 'page',
				'post_title'   => _x( 'Contact', 'Theme starter content' ),
				'post_content' => _x( 'This is a page with some basic contact information, such as an address and phone number. You might also try a plugin to add a contact form.', 'Theme starter content' ),
			),
			'blog'             => array(
				'post_type'  => 'page',
				'post_title' => _x( 'Blog', 'Theme starter content' ),
			),
			'news'             => array(
				'post_type'  => 'page',
				'post_title' => _x( 'News', 'Theme starter content' ),
			),

			'homepage-section' => array(
				'post_type'    => 'page',
				'post_title'   => _x( 'A homepage section', 'Theme starter content' ),
				'post_content' => _x( 'This is an example of a homepage section. Homepage sections can be any page other than the homepage itself, including the page that shows your latest blog posts.', 'Theme starter content' ),
			),
		),
	);

	$content = array();

	foreach ( $config as $type => $args ) {
		switch ( $type ) {
			// Use options and theme_mods as-is.
			case 'options':
			case 'theme_mods':
				$content[ $type ] = $config[ $type ];
				break;

			// Widgets are grouped into sidebars.
			case 'widgets':
				foreach ( $config[ $type ] as $sidebar_id => $widgets ) {
					foreach ( $widgets as $id => $widget ) {
						if ( is_array( $widget ) ) {

							// Item extends core content.
							if ( ! empty( $core_content[ $type ][ $id ] ) ) {
								$widget = array(
									$core_content[ $type ][ $id ][0],
									array_merge( $core_content[ $type ][ $id ][1], $widget ),
								);
							}

							$content[ $type ][ $sidebar_id ][] = $widget;
						} elseif ( is_string( $widget )
							&& ! empty( $core_content[ $type ] )
							&& ! empty( $core_content[ $type ][ $widget ] )
						) {
							$content[ $type ][ $sidebar_id ][] = $core_content[ $type ][ $widget ];
						}
					}
				}
				break;

			// And nav menu items are grouped into nav menus.
			case 'nav_menus':
				foreach ( $config[ $type ] as $nav_menu_location => $nav_menu ) {

					// Ensure nav menus get a name.
					if ( empty( $nav_menu['name'] ) ) {
						$nav_menu['name'] = $nav_menu_location;
					}

					$content[ $type ][ $nav_menu_location ]['name'] = $nav_menu['name'];

					foreach ( $nav_menu['items'] as $id => $nav_menu_item ) {
						if ( is_array( $nav_menu_item ) ) {

							// Item extends core content.
							if ( ! empty( $core_content[ $type ][ $id ] ) ) {
								$nav_menu_item = array_merge( $core_content[ $type ][ $id ], $nav_menu_item );
							}

							$content[ $type ][ $nav_menu_location ]['items'][] = $nav_menu_item;
						} elseif ( is_string( $nav_menu_item )
							&& ! empty( $core_content[ $type ] )
							&& ! empty( $core_content[ $type ][ $nav_menu_item ] )
						) {
							$content[ $type ][ $nav_menu_location ]['items'][] = $core_content[ $type ][ $nav_menu_item ];
						}
					}
				}
				break;

			// Attachments are posts but have special treatment.
			case 'attachments':
				foreach ( $config[ $type ] as $id => $item ) {
					if ( ! empty( $item['file'] ) ) {
						$content[ $type ][ $id ] = $item;
					}
				}
				break;

			// All that's left now are posts (besides attachments).
			// Not a default case for the sake of clarity and future work.
			case 'posts':
				foreach ( $config[ $type ] as $id => $item ) {
					if ( is_array( $item ) ) {

						// Item extends core content.
						if ( ! empty( $core_content[ $type ][ $id ] ) ) {
							$item = array_merge( $core_content[ $type ][ $id ], $item );
						}

						// Enforce a subset of fields.
						$content[ $type ][ $id ] = wp_array_slice_assoc(
							$item,
							array(
								'post_type',
								'post_title',
								'post_excerpt',
								'post_name',
								'post_content',
								'menu_order',
								'comment_status',
								'thumbnail',
								'template',
							)
						);
					} elseif ( is_string( $item ) && ! empty( $core_content[ $type ][ $item ] ) ) {
						$content[ $type ][ $item ] = $core_content[ $type ][ $item ];
					}
				}
				break;
		}
	}

	/**
	 * Filters the expanded array of starter content.
	 *
	 * @since 4.7.0
	 *
	 * @param array $content Array of starter content.
	 * @param array $config  Array of theme-specific starter content configuration.
	 */
	return apply_filters( 'get_theme_starter_content', $content, $config );
}

/**
 * Registers theme support for a given feature.
 *
 * Must be called in the theme's functions.php file to work.
 * If attached to a hook, it must be {@see 'after_setup_theme'}.
 * The {@see 'init'} hook may be too late for some features.
 *
 * Example usage:
 *
 *     add_theme_support( 'title-tag' );
 *     add_theme_support( 'custom-logo', array(
 *         'height' => 480,
 *         'width'  => 720,
 *     ) );
 *
 * @since 2.9.0
 * @since 3.4.0    The `custom-header-uploads` feature was deprecated.
 * @since 3.6.0    The `html5` feature was added.
 * @since 3.6.1    The `html5` feature requires an array of types to be passed. Defaults to
 *                 'comment-list', 'comment-form', 'search-form' for backward compatibility.
 * @since 3.9.0    The `html5` feature now also accepts 'gallery' and 'caption'.
 * @since 4.1.0    The `title-tag` feature was added.
 * @since 4.5.0    The `customize-selective-refresh-widgets` feature was added.
 * @since 4.7.0    The `starter-content` feature was added.
 * @since 5.0.0    The `responsive-embeds`, `align-wide`, `dark-editor-style`, `disable-custom-colors`,
 *                 `disable-custom-font-sizes`, `editor-color-palette`, `editor-font-sizes`
 *                 and `editor-styles` features were added.
 * @since 5.3.0    The `html5` feature now also accepts 'script' and 'style'.
 * @since 5.3.0    Formalized the existing and already documented `...$args` parameter
 *                 by adding it to the function signature.
 * @since 5.5.0    The `custom-logo` feature now also accepts 'unlink-homepage-logo'.
 * @since 5.6.0    The `post-formats` feature warns if no array is passed as the second parameter.
 * @since 6.0.0    The `html5` feature warns if no array is passed as the second parameter.
 * @since CP-2.0.0 The `html5` feature warns if used as it is no longer required.
 *
 * @global array $_wp_theme_features
 *
 * @param string $feature The feature being added. Likely core values include:
 *                          - 'admin-bar'
 *                          - 'align-wide'
 *                          - 'automatic-feed-links'
 *                          - 'custom-background'
 *                          - 'custom-header'
 *                          - 'custom-line-height'
 *                          - 'custom-logo'
 *                          - 'customize-selective-refresh-widgets'
 *                          - 'custom-spacing'
 *                          - 'custom-units'
 *                          - 'dark-editor-style'
 *                          - 'disable-custom-colors'
 *                          - 'disable-custom-font-sizes'
 *                          - 'editor-color-palette'
 *                          - 'editor-gradient-presets'
 *                          - 'editor-font-sizes'
 *                          - 'editor-styles'
 *                          - 'featured-content'
 *                          - 'html5'
 *                          - 'menus'
 *                          - 'post-formats'
 *                          - 'post-thumbnails'
 *                          - 'responsive-embeds'
 *                          - 'starter-content'
 *                          - 'title-tag'
 *                          - 'widgets'
 * @param mixed  ...$args Optional extra arguments to pass along with certain features.
 * @return void|false Void on success, false on failure.
 */
function add_theme_support( $feature, ...$args ) {
	global $_wp_theme_features;

	if ( ! $args ) {
		$args = true;
	}

	switch ( $feature ) {
		case 'post-thumbnails':
			// All post types are already supported.
			if ( true === get_theme_support( 'post-thumbnails' ) ) {
				return;
			}

			/*
			 * Merge post types with any that already declared their support
			 * for post thumbnails.
			 */
			if ( isset( $args[0] ) && is_array( $args[0] ) && isset( $_wp_theme_features['post-thumbnails'] ) ) {
				$args[0] = array_unique( array_merge( $_wp_theme_features['post-thumbnails'][0], $args[0] ) );
			}

			break;

		case 'post-formats':
			if ( isset( $args[0] ) && is_array( $args[0] ) ) {
				$post_formats = get_post_format_slugs();
				unset( $post_formats['standard'] );

				$args[0] = array_intersect( $args[0], array_keys( $post_formats ) );
			} else {
				_doing_it_wrong(
					"add_theme_support( 'post-formats' )",
					__( 'You need to pass an array of post formats.' ),
					'5.6.0'
				);
				return false;
			}
			break;

		case 'html5':
			// Since CP-2.0.0 HTLM5 has been expected as theme default
			_deprecated_argument(
				"add_theme_support( 'html5' )",
				'CP-2.0.0',
				__( 'HTML5 is the default.' )
			);

			return true;
			break;

		case 'custom-logo':
			if ( true === $args ) {
				$args = array( 0 => array() );
			}
			$defaults = array(
				'width'                => null,
				'height'               => null,
				'flex-width'           => false,
				'flex-height'          => false,
				'header-text'          => '',
				'unlink-homepage-logo' => false,
			);
			$args[0]  = wp_parse_args( array_intersect_key( $args[0], $defaults ), $defaults );

			// Allow full flexibility if no size is specified.
			if ( is_null( $args[0]['width'] ) && is_null( $args[0]['height'] ) ) {
				$args[0]['flex-width']  = true;
				$args[0]['flex-height'] = true;
			}
			break;

		case 'custom-header-uploads':
			return add_theme_support( 'custom-header', array( 'uploads' => true ) );

		case 'custom-header':
			if ( true === $args ) {
				$args = array( 0 => array() );
			}

			$defaults = array(
				'default-image'          => '',
				'random-default'         => false,
				'width'                  => 0,
				'height'                 => 0,
				'flex-height'            => false,
				'flex-width'             => false,
				'default-text-color'     => '',
				'header-text'            => true,
				'uploads'                => true,
				'wp-head-callback'       => '',
				'admin-head-callback'    => '',
				'admin-preview-callback' => '',
				'video'                  => false,
				'video-active-callback'  => 'is_front_page',
			);

			$jit = isset( $args[0]['__jit'] );
			unset( $args[0]['__jit'] );

			// Merge in data from previous add_theme_support() calls.
			// The first value registered wins. (A child theme is set up first.)
			if ( isset( $_wp_theme_features['custom-header'] ) ) {
				$args[0] = wp_parse_args( $_wp_theme_features['custom-header'][0], $args[0] );
			}

			// Load in the defaults at the end, as we need to insure first one wins.
			// This will cause all constants to be defined, as each arg will then be set to the default.
			if ( $jit ) {
				$args[0] = wp_parse_args( $args[0], $defaults );
			}

			/*
			 * If a constant was defined, use that value. Otherwise, define the constant to ensure
			 * the constant is always accurate (and is not defined later,  overriding our value).
			 * As stated above, the first value wins.
			 * Once we get to wp_loaded (just-in-time), define any constants we haven't already.
			 * Constants are lame. Don't reference them. This is just for backward compatibility.
			 */

			if ( defined( 'NO_HEADER_TEXT' ) ) {
				$args[0]['header-text'] = ! NO_HEADER_TEXT;
			} elseif ( isset( $args[0]['header-text'] ) ) {
				define( 'NO_HEADER_TEXT', empty( $args[0]['header-text'] ) );
			}

			if ( defined( 'HEADER_IMAGE_WIDTH' ) ) {
				$args[0]['width'] = (int) HEADER_IMAGE_WIDTH;
			} elseif ( isset( $args[0]['width'] ) ) {
				define( 'HEADER_IMAGE_WIDTH', (int) $args[0]['width'] );
			}

			if ( defined( 'HEADER_IMAGE_HEIGHT' ) ) {
				$args[0]['height'] = (int) HEADER_IMAGE_HEIGHT;
			} elseif ( isset( $args[0]['height'] ) ) {
				define( 'HEADER_IMAGE_HEIGHT', (int) $args[0]['height'] );
			}

			if ( defined( 'HEADER_TEXTCOLOR' ) ) {
				$args[0]['default-text-color'] = HEADER_TEXTCOLOR;
			} elseif ( isset( $args[0]['default-text-color'] ) ) {
				define( 'HEADER_TEXTCOLOR', $args[0]['default-text-color'] );
			}

			if ( defined( 'HEADER_IMAGE' ) ) {
				$args[0]['default-image'] = HEADER_IMAGE;
			} elseif ( isset( $args[0]['default-image'] ) ) {
				define( 'HEADER_IMAGE', $args[0]['default-image'] );
			}

			if ( $jit && ! empty( $args[0]['default-image'] ) ) {
				$args[0]['random-default'] = false;
			}

			// If headers are supported, and we still don't have a defined width or height,
			// we have implicit flex sizes.
			if ( $jit ) {
				if ( empty( $args[0]['width'] ) && empty( $args[0]['flex-width'] ) ) {
					$args[0]['flex-width'] = true;
				}
				if ( empty( $args[0]['height'] ) && empty( $args[0]['flex-height'] ) ) {
					$args[0]['flex-height'] = true;
				}
			}

			break;

		case 'custom-background':
			if ( true === $args ) {
				$args = array( 0 => array() );
			}

			$defaults = array(
				'default-image'          => '',
				'default-preset'         => 'default',
				'default-position-x'     => 'left',
				'default-position-y'     => 'top',
				'default-size'           => 'auto',
				'default-repeat'         => 'repeat',
				'default-attachment'     => 'scroll',
				'default-color'          => '',
				'wp-head-callback'       => '_custom_background_cb',
				'admin-head-callback'    => '',
				'admin-preview-callback' => '',
			);

			$jit = isset( $args[0]['__jit'] );
			unset( $args[0]['__jit'] );

			// Merge in data from previous add_theme_support() calls. The first value registered wins.
			if ( isset( $_wp_theme_features['custom-background'] ) ) {
				$args[0] = wp_parse_args( $_wp_theme_features['custom-background'][0], $args[0] );
			}

			if ( $jit ) {
				$args[0] = wp_parse_args( $args[0], $defaults );
			}

			if ( defined( 'BACKGROUND_COLOR' ) ) {
				$args[0]['default-color'] = BACKGROUND_COLOR;
			} elseif ( isset( $args[0]['default-color'] ) || $jit ) {
				define( 'BACKGROUND_COLOR', $args[0]['default-color'] );
			}

			if ( defined( 'BACKGROUND_IMAGE' ) ) {
				$args[0]['default-image'] = BACKGROUND_IMAGE;
			} elseif ( isset( $args[0]['default-image'] ) || $jit ) {
				define( 'BACKGROUND_IMAGE', $args[0]['default-image'] );
			}

			break;

		// Ensure that 'title-tag' is accessible in the admin.
		case 'title-tag':
			// Can be called in functions.php but must happen before wp_loaded, i.e. not in header.php.
			if ( did_action( 'wp_loaded' ) ) {
				_doing_it_wrong(
					"add_theme_support( 'title-tag' )",
					sprintf(
						/* translators: 1: title-tag, 2: wp_loaded */
						__( 'Theme support for %1$s should be registered before the %2$s hook.' ),
						'<code>title-tag</code>',
						'<code>wp_loaded</code>'
					),
					'4.1.0'
				);

				return false;
			}

			break;

		case 'body-only':
			add_theme_support( 'automatic-feed-links' );
			add_theme_support( 'title-tag' );

	}

	$_wp_theme_features[ $feature ] = $args;
}

/**
 * Registers the internal custom header and background routines.
 *
 * @since 3.4.0
 * @access private
 *
 * @global Custom_Image_Header $custom_image_header
 * @global Custom_Background   $custom_background
 */
function _custom_header_background_just_in_time() {
	global $custom_image_header, $custom_background;

	if ( current_theme_supports( 'custom-header' ) ) {
		// In case any constants were defined after an add_custom_image_header() call, re-run.
		add_theme_support( 'custom-header', array( '__jit' => true ) );

		$args = get_theme_support( 'custom-header' );
		if ( $args[0]['wp-head-callback'] ) {
			add_action( 'wp_head', $args[0]['wp-head-callback'] );
		}

		if ( is_admin() ) {
			require_once ABSPATH . 'wp-admin/includes/class-custom-image-header.php';
			$custom_image_header = new Custom_Image_Header( $args[0]['admin-head-callback'], $args[0]['admin-preview-callback'] );
		}
	}

	if ( current_theme_supports( 'custom-background' ) ) {
		// In case any constants were defined after an add_custom_background() call, re-run.
		add_theme_support( 'custom-background', array( '__jit' => true ) );

		$args = get_theme_support( 'custom-background' );
		add_action( 'wp_head', $args[0]['wp-head-callback'] );

		if ( is_admin() ) {
			require_once ABSPATH . 'wp-admin/includes/class-custom-background.php';
			$custom_background = new Custom_Background( $args[0]['admin-head-callback'], $args[0]['admin-preview-callback'] );
		}
	}
}

/**
 * Adds CSS to hide header text for custom logo, based on Customizer setting.
 *
 * @since 4.5.0
 * @access private
 */
function _custom_logo_header_styles() {
	if ( ! current_theme_supports( 'custom-header', 'header-text' )
		&& get_theme_support( 'custom-logo', 'header-text' )
		&& ! get_theme_mod( 'header_text', true )
	) {
		$classes = (array) get_theme_support( 'custom-logo', 'header-text' );
		$classes = array_map( 'sanitize_html_class', $classes );
		$classes = '.' . implode( ', .', $classes );
		?>
		<!-- Custom Logo: hide header text -->
		<style id="custom-logo-css">
			<?php echo $classes; ?> {
				position: absolute;
				clip: rect(1px, 1px, 1px, 1px);
			}
		</style>
		<?php
	}
}

/**
 * Gets the theme support arguments passed when registering that support.
 *
 * Example usage:
 *
 *     get_theme_support( 'custom-logo' );
 *     get_theme_support( 'custom-header', 'width' );
 *
 * @since 3.1.0
 * @since 5.3.0 Formalized the existing and already documented `...$args` parameter
 *              by adding it to the function signature.
 *
 * @global array $_wp_theme_features
 *
 * @param string $feature The feature to check. See add_theme_support() for the list
 *                        of possible values.
 * @param mixed  ...$args Optional extra arguments to be checked against certain features.
 * @return mixed The array of extra arguments or the value for the registered feature.
 */
function get_theme_support( $feature, ...$args ) {
	global $_wp_theme_features;

	if ( ! isset( $_wp_theme_features[ $feature ] ) ) {
		return false;
	}

	if ( ! $args ) {
		return $_wp_theme_features[ $feature ];
	}

	switch ( $feature ) {
		case 'custom-logo':
		case 'custom-header':
		case 'custom-background':
			if ( isset( $_wp_theme_features[ $feature ][0][ $args[0] ] ) ) {
				return $_wp_theme_features[ $feature ][0][ $args[0] ];
			}
			return false;

		default:
			return $_wp_theme_features[ $feature ];
	}
}

/**
 * Allows a theme to de-register its support of a certain feature
 *
 * Should be called in the theme's functions.php file. Generally would
 * be used for child themes to override support from the parent theme.
 *
 * @since 3.0.0
 *
 * @see add_theme_support()
 *
 * @param string $feature The feature being removed. See add_theme_support() for the list
 *                        of possible values.
 * @return bool|void Whether feature was removed.
 */
function remove_theme_support( $feature ) {
	// Do not remove internal registrations that are not used directly by themes.
	if ( in_array( $feature, array( 'editor-style', 'widgets', 'menus' ), true ) ) {
		return false;
	}

	return _remove_theme_support( $feature );
}

/**
 * Do not use. Removes theme support internally without knowledge of those not used
 * by themes directly.
 *
 * @access private
 * @since 3.1.0
 * @global array               $_wp_theme_features
 * @global Custom_Image_Header $custom_image_header
 * @global Custom_Background   $custom_background
 *
 * @param string $feature The feature being removed. See add_theme_support() for the list
 *                        of possible values.
 * @return bool True if support was removed, false if the feature was not registered.
 */
function _remove_theme_support( $feature ) {
	global $_wp_theme_features;

	switch ( $feature ) {
		case 'custom-header-uploads':
			if ( ! isset( $_wp_theme_features['custom-header'] ) ) {
				return false;
			}
			add_theme_support( 'custom-header', array( 'uploads' => false ) );
			return; // Do not continue - custom-header-uploads no longer exists.
	}

	if ( ! isset( $_wp_theme_features[ $feature ] ) ) {
		return false;
	}

	switch ( $feature ) {
		case 'custom-header':
			if ( ! did_action( 'wp_loaded' ) ) {
				break;
			}
			$support = get_theme_support( 'custom-header' );
			if ( isset( $support[0]['wp-head-callback'] ) ) {
				remove_action( 'wp_head', $support[0]['wp-head-callback'] );
			}
			if ( isset( $GLOBALS['custom_image_header'] ) ) {
				remove_action( 'admin_menu', array( $GLOBALS['custom_image_header'], 'init' ) );
				unset( $GLOBALS['custom_image_header'] );
			}
			break;

		case 'custom-background':
			if ( ! did_action( 'wp_loaded' ) ) {
				break;
			}
			$support = get_theme_support( 'custom-background' );
			if ( isset( $support[0]['wp-head-callback'] ) ) {
				remove_action( 'wp_head', $support[0]['wp-head-callback'] );
			}
			remove_action( 'admin_menu', array( $GLOBALS['custom_background'], 'init' ) );
			unset( $GLOBALS['custom_background'] );
			break;
	}

	unset( $_wp_theme_features[ $feature ] );

	return true;
}

/**
 * Checks a theme's support for a given feature.
 *
 * Example usage:
 *
 *     current_theme_supports( 'custom-logo' );
 *
 * @since 2.9.0
 * @since 5.3.0    Formalized the existing and already documented `...$args` parameter
 *                 by adding it to the function signature.
 * @since CP-2.0.0 HTML5 is expected to be supported by default.
 *
 * @global array $_wp_theme_features
 *
 * @param string $feature The feature being checked. See add_theme_support() for the list
 *                        of possible values.
 * @param mixed  ...$args Optional extra arguments to be checked against certain features.
 * @return bool True if the active theme supports the feature, false otherwise.
 */
function current_theme_supports( $feature, ...$args ) {
	global $_wp_theme_features;

	if ( 'custom-header-uploads' === $feature ) {
		return current_theme_supports( 'custom-header', 'uploads' );
	}

	if ( 'html5' === strtolower( $feature ) ) {
		return true;
	}

	if ( ! isset( $_wp_theme_features[ $feature ] ) ) {
		return false;
	}

	// If no args passed then no extra checks need to be performed.
	if ( ! $args ) {
		/** This filter is documented in wp-includes/theme.php */
		return apply_filters( "current_theme_supports-{$feature}", true, $args, $_wp_theme_features[ $feature ] ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores
	}

	switch ( $feature ) {
		case 'post-thumbnails':
			/*
			 * post-thumbnails can be registered for only certain content/post types
			 * by passing an array of types to add_theme_support().
			 * If no array was passed, then any type is accepted.
			 */
			if ( true === $_wp_theme_features[ $feature ] ) {  // Registered for all types.
				return true;
			}
			$content_type = $args[0];
			return in_array( $content_type, $_wp_theme_features[ $feature ][0], true );

		case 'post-formats':
			/*
			 * Specific post formats can be registered by passing an array of types
			 * to add_theme_support().
			 */
			$type = $args[0];
			return in_array( $type, $_wp_theme_features[ $feature ][0], true );

		case 'custom-logo':
		case 'custom-header':
		case 'custom-background':
			// Specific capabilities can be registered by passing an array to add_theme_support().
			return ( isset( $_wp_theme_features[ $feature ][0][ $args[0] ] ) && $_wp_theme_features[ $feature ][0][ $args[0] ] );
	}

	/**
	 * Filters whether the active theme supports a specific feature.
	 *
	 * The dynamic portion of the hook name, `$feature`, refers to the specific
	 * theme feature. See add_theme_support() for the list of possible values.
	 *
	 * @since 3.4.0
	 *
	 * @param bool   $supports Whether the active theme supports the given feature. Default true.
	 * @param array  $args     Array of arguments for the feature.
	 * @param string $feature  The theme feature.
	 */
	return apply_filters( "current_theme_supports-{$feature}", true, $args, $_wp_theme_features[ $feature ] ); // phpcs:ignore WordPress.NamingConventions.ValidHookName.UseUnderscores
}

/**
 * Checks a theme's support for a given feature before loading the functions which implement it.
 *
 * @since 2.9.0
 *
 * @param string $feature The feature being checked. See add_theme_support() for the list
 *                        of possible values.
 * @param string $file    Path to the file.
 * @return bool True if the active theme supports the supplied feature, false otherwise.
 */
function require_if_theme_supports( $feature, $file ) {
	if ( current_theme_supports( $feature ) ) {
		require $file;
		return true;
	}
	return false;
}

/**
 * Registers a theme feature for use in add_theme_support().
 *
 * This does not indicate that the active theme supports the feature, it only describes
 * the feature's supported options.
 *
 * @since 5.5.0
 *
 * @see add_theme_support()
 *
 * @global array $_wp_registered_theme_features
 *
 * @param string $feature The name uniquely identifying the feature. See add_theme_support()
 *                        for the list of possible values.
 * @param array  $args {
 *     Data used to describe the theme.
 *
 *     @type string     $type         The type of data associated with this feature.
 *                                    Valid values are 'string', 'boolean', 'integer',
 *                                    'number', 'array', and 'object'. Defaults to 'boolean'.
 *     @type bool       $variadic     Does this feature utilize the variadic support
 *                                    of add_theme_support(), or are all arguments specified
 *                                    as the second parameter. Must be used with the "array" type.
 *     @type string     $description  A short description of the feature. Included in
 *                                    the Themes REST API schema. Intended for developers.
 *     @type bool|array $show_in_rest {
 *         Whether this feature should be included in the Themes REST API endpoint.
 *         Defaults to not being included. When registering an 'array' or 'object' type,
 *         this argument must be an array with the 'schema' key.
 *
 *         @type array    $schema           Specifies the JSON Schema definition describing
 *                                          the feature. If any objects in the schema do not include
 *                                          the 'additionalProperties' keyword, it is set to false.
 *         @type string   $name             An alternate name to be used as the property name
 *                                          in the REST API.
 *         @type callable $prepare_callback A function used to format the theme support in the REST API.
 *                                          Receives the raw theme support value.
 *      }
 * }
 * @return true|WP_Error True if the theme feature was successfully registered, a WP_Error object if not.
 */
function register_theme_feature( $feature, $args = array() ) {
	global $_wp_registered_theme_features;

	if ( ! is_array( $_wp_registered_theme_features ) ) {
		$_wp_registered_theme_features = array();
	}

	$defaults = array(
		'type'         => 'boolean',
		'variadic'     => false,
		'description'  => '',
		'show_in_rest' => false,
	);

	$args = wp_parse_args( $args, $defaults );

	if ( true === $args['show_in_rest'] ) {
		$args['show_in_rest'] = array();
	}

	if ( is_array( $args['show_in_rest'] ) ) {
		$args['show_in_rest'] = wp_parse_args(
			$args['show_in_rest'],
			array(
				'schema'           => array(),
				'name'             => $feature,
				'prepare_callback' => null,
			)
		);
	}

	if ( ! in_array( $args['type'], array( 'string', 'boolean', 'integer', 'number', 'array', 'object' ), true ) ) {
		return new WP_Error(
			'invalid_type',
			__( 'The feature "type" is not valid JSON Schema type.' )
		);
	}

	if ( true === $args['variadic'] && 'array' !== $args['type'] ) {
		return new WP_Error(
			'variadic_must_be_array',
			__( 'When registering a "variadic" theme feature, the "type" must be an "array".' )
		);
	}

	if ( false !== $args['show_in_rest'] && in_array( $args['type'], array( 'array', 'object' ), true ) ) {
		if ( ! is_array( $args['show_in_rest'] ) || empty( $args['show_in_rest']['schema'] ) ) {
			return new WP_Error(
				'missing_schema',
				__( 'When registering an "array" or "object" feature to show in the REST API, the feature\'s schema must also be defined.' )
			);
		}

		if ( 'array' === $args['type'] && ! isset( $args['show_in_rest']['schema']['items'] ) ) {
			return new WP_Error(
				'missing_schema_items',
				__( 'When registering an "array" feature, the feature\'s schema must include the "items" keyword.' )
			);
		}

		if ( 'object' === $args['type'] && ! isset( $args['show_in_rest']['schema']['properties'] ) ) {
			return new WP_Error(
				'missing_schema_properties',
				__( 'When registering an "object" feature, the feature\'s schema must include the "properties" keyword.' )
			);
		}
	}

	if ( is_array( $args['show_in_rest'] ) ) {
		if ( isset( $args['show_in_rest']['prepare_callback'] )
			&& ! is_callable( $args['show_in_rest']['prepare_callback'] )
		) {
			return new WP_Error(
				'invalid_rest_prepare_callback',
				sprintf(
					/* translators: %s: prepare_callback */
					__( 'The "%s" must be a callable function.' ),
					'prepare_callback'
				)
			);
		}

		$args['show_in_rest']['schema'] = wp_parse_args(
			$args['show_in_rest']['schema'],
			array(
				'description' => $args['description'],
				'type'        => $args['type'],
				'default'     => false,
			)
		);

		if ( is_bool( $args['show_in_rest']['schema']['default'] )
			&& ! in_array( 'boolean', (array) $args['show_in_rest']['schema']['type'], true )
		) {
			// Automatically include the "boolean" type when the default value is a boolean.
			$args['show_in_rest']['schema']['type'] = (array) $args['show_in_rest']['schema']['type'];
			array_unshift( $args['show_in_rest']['schema']['type'], 'boolean' );
		}

		$args['show_in_rest']['schema'] = rest_default_additional_properties_to_false( $args['show_in_rest']['schema'] );
	}

	$_wp_registered_theme_features[ $feature ] = $args;

	return true;
}

/**
 * Gets the list of registered theme features.
 *
 * @since 5.5.0
 *
 * @global array $_wp_registered_theme_features
 *
 * @return array[] List of theme features, keyed by their name.
 */
function get_registered_theme_features() {
	global $_wp_registered_theme_features;

	if ( ! is_array( $_wp_registered_theme_features ) ) {
		return array();
	}

	return $_wp_registered_theme_features;
}

/**
 * Gets the registration config for a theme feature.
 *
 * @since 5.5.0
 *
 * @global array $_wp_registered_theme_features
 *
 * @param string $feature The feature name. See add_theme_support() for the list
 *                        of possible values.
 * @return array|null The registration args, or null if the feature was not registered.
 */
function get_registered_theme_feature( $feature ) {
	global $_wp_registered_theme_features;

	if ( ! is_array( $_wp_registered_theme_features ) ) {
		return null;
	}

	return isset( $_wp_registered_theme_features[ $feature ] ) ? $_wp_registered_theme_features[ $feature ] : null;
}

/**
 * Checks an attachment being deleted to see if it's a header or background image.
 *
 * If true it removes the theme modification which would be pointing at the deleted
 * attachment.
 *
 * @access private
 * @since 3.0.0
 * @since 4.3.0 Also removes `header_image_data`.
 * @since 4.5.0 Also removes custom logo theme mods.
 *
 * @param int $id The attachment ID.
 */
function _delete_attachment_theme_mod( $id ) {
	$attachment_image = wp_get_attachment_url( $id );
	$header_image     = get_header_image();
	$background_image = get_background_image();
	$custom_logo_id   = get_theme_mod( 'custom_logo' );

	if ( $custom_logo_id && $custom_logo_id == $id ) {
		remove_theme_mod( 'custom_logo' );
		remove_theme_mod( 'header_text' );
	}

	if ( $header_image && $header_image == $attachment_image ) {
		remove_theme_mod( 'header_image' );
		remove_theme_mod( 'header_image_data' );
	}

	if ( $background_image && $background_image == $attachment_image ) {
		remove_theme_mod( 'background_image' );
	}
}

/**
 * Checks if a theme has been changed and runs 'after_switch_theme' hook on the next WP load.
 *
 * See {@see 'after_switch_theme'}.
 *
 * @since 3.3.0
 */
function check_theme_switched() {
	$stylesheet = get_option( 'theme_switched' );

	if ( $stylesheet ) {
		$old_theme = wp_get_theme( $stylesheet );

		// Prevent widget & menu mapping from running since Customizer already called it up front.
		if ( get_option( 'theme_switched_via_customizer' ) ) {
			remove_action( 'after_switch_theme', '_wp_menus_changed' );
			remove_action( 'after_switch_theme', '_wp_sidebars_changed' );
			update_option( 'theme_switched_via_customizer', false );
		}

		if ( $old_theme->exists() ) {
			/**
			 * Fires on the first WP load after a theme switch if the old theme still exists.
			 *
			 * This action fires multiple times and the parameters differs
			 * according to the context, if the old theme exists or not.
			 * If the old theme is missing, the parameter will be the slug
			 * of the old theme.
			 *
			 * @since 3.3.0
			 *
			 * @param string   $old_name  Old theme name.
			 * @param WP_Theme $old_theme WP_Theme instance of the old theme.
			 */
			do_action( 'after_switch_theme', $old_theme->get( 'Name' ), $old_theme );
		} else {
			/** This action is documented in wp-includes/theme.php */
			do_action( 'after_switch_theme', $stylesheet, $old_theme );
		}

		flush_rewrite_rules();

		update_option( 'theme_switched', false );
	}
}

/**
 * Includes and instantiates the WP_Customize_Manager class.
 *
 * Loads the Customizer at plugins_loaded when accessing the customize.php admin
 * page or when any request includes a wp_customize=on param or a customize_changeset
 * param (a UUID). This param is a signal for whether to bootstrap the Customizer when
 * WordPress is loading, especially in the Customizer preview
 * or when making Customizer Ajax requests for widgets or menus.
 *
 * @since 3.4.0
 *
 * @global WP_Customize_Manager $wp_customize
 */
function _wp_customize_include() {

	$is_customize_admin_page = ( is_admin() && 'customize.php' === basename( $_SERVER['PHP_SELF'] ) );
	$should_include          = (
		$is_customize_admin_page
		||
		( isset( $_REQUEST['wp_customize'] ) && 'on' === $_REQUEST['wp_customize'] )
		||
		( ! empty( $_GET['customize_changeset_uuid'] ) || ! empty( $_POST['customize_changeset_uuid'] ) )
	);

	if ( ! $should_include ) {
		return;
	}

	/*
	 * Note that wp_unslash() is not being used on the input vars because it is
	 * called before wp_magic_quotes() gets called. Besides this fact, none of
	 * the values should contain any characters needing slashes anyway.
	 */
	$keys       = array(
		'changeset_uuid',
		'customize_changeset_uuid',
		'customize_theme',
		'theme',
		'customize_messenger_channel',
		'customize_autosaved',
	);
	$input_vars = array_merge(
		wp_array_slice_assoc( $_GET, $keys ),
		wp_array_slice_assoc( $_POST, $keys )
	);

	$theme             = null;
	$autosaved         = null;
	$messenger_channel = null;

	// Value false indicates UUID should be determined after_setup_theme
	// to either re-use existing saved changeset or else generate a new UUID if none exists.
	$changeset_uuid = false;

	// Set initially fo false since defaults to true for back-compat;
	// can be overridden via the customize_changeset_branching filter.
	$branching = false;

	if ( $is_customize_admin_page && isset( $input_vars['changeset_uuid'] ) ) {
		$changeset_uuid = sanitize_key( $input_vars['changeset_uuid'] );
	} elseif ( ! empty( $input_vars['customize_changeset_uuid'] ) ) {
		$changeset_uuid = sanitize_key( $input_vars['customize_changeset_uuid'] );
	}

	// Note that theme will be sanitized via WP_Theme.
	if ( $is_customize_admin_page && isset( $input_vars['theme'] ) ) {
		$theme = $input_vars['theme'];
	} elseif ( isset( $input_vars['customize_theme'] ) ) {
		$theme = $input_vars['customize_theme'];
	}

	if ( ! empty( $input_vars['customize_autosaved'] ) ) {
		$autosaved = true;
	}

	if ( isset( $input_vars['customize_messenger_channel'] ) ) {
		$messenger_channel = sanitize_key( $input_vars['customize_messenger_channel'] );
	}

	/*
	 * Note that settings must be previewed even outside the customizer preview
	 * and also in the customizer pane itself. This is to enable loading an existing
	 * changeset into the customizer. Previewing the settings only has to be prevented
	 * here in the case of a customize_save action because this will cause WP to think
	 * there is nothing changed that needs to be saved.
	 */
	$is_customize_save_action = (
		wp_doing_ajax()
		&&
		isset( $_REQUEST['action'] )
		&&
		'customize_save' === wp_unslash( $_REQUEST['action'] )
	);
	$settings_previewed       = ! $is_customize_save_action;

	require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
	$GLOBALS['wp_customize'] = new WP_Customize_Manager(
		compact(
			'changeset_uuid',
			'theme',
			'messenger_channel',
			'settings_previewed',
			'autosaved',
			'branching'
		)
	);
}

/**
 * Publishes a snapshot's changes.
 *
 * @since 4.7.0
 * @access private
 *
 * @global wpdb                 $wpdb         WordPress database abstraction object.
 * @global WP_Customize_Manager $wp_customize Customizer instance.
 *
 * @param string  $new_status     New post status.
 * @param string  $old_status     Old post status.
 * @param WP_Post $changeset_post Changeset post object.
 */
function _wp_customize_publish_changeset( $new_status, $old_status, $changeset_post ) {
	global $wp_customize, $wpdb;

	$is_publishing_changeset = (
		'customize_changeset' === $changeset_post->post_type
		&&
		'publish' === $new_status
		&&
		'publish' !== $old_status
	);
	if ( ! $is_publishing_changeset ) {
		return;
	}

	if ( empty( $wp_customize ) ) {
		require_once ABSPATH . WPINC . '/class-wp-customize-manager.php';
		$wp_customize = new WP_Customize_Manager(
			array(
				'changeset_uuid'     => $changeset_post->post_name,
				'settings_previewed' => false,
			)
		);
	}

	if ( ! did_action( 'customize_register' ) ) {
		/*
		 * When running from CLI or Cron, the customize_register action will need
		 * to be triggered in order for core, themes, and plugins to register their
		 * settings. Normally core will add_action( 'customize_register' ) at
		 * priority 10 to register the core settings, and if any themes/plugins
		 * also add_action( 'customize_register' ) at the same priority, they
		 * will have a $wp_customize with those settings registered since they
		 * call add_action() afterward, normally. However, when manually doing
		 * the customize_register action after the setup_theme, then the order
		 * will be reversed for two actions added at priority 10, resulting in
		 * the core settings no longer being available as expected to themes/plugins.
		 * So the following manually calls the method that registers the core
		 * settings up front before doing the action.
		 */
		remove_action( 'customize_register', array( $wp_customize, 'register_controls' ) );
		$wp_customize->register_controls();

		/** This filter is documented in wp-includes/class-wp-customize-manager.php */
		do_action( 'customize_register', $wp_customize );
	}
	$wp_customize->_publish_changeset_values( $changeset_post->ID );

	/*
	 * Trash the changeset post if revisions are not enabled. Unpublished
	 * changesets by default get garbage collected due to the auto-draft status.
	 * When a changeset post is published, however, it would no longer get cleaned
	 * out. This is a problem when the changeset posts are never displayed anywhere,
	 * since they would just be endlessly piling up. So here we use the revisions
	 * feature to indicate whether or not a published changeset should get trashed
	 * and thus garbage collected.
	 */
	if ( ! wp_revisions_enabled( $changeset_post ) ) {
		$wp_customize->trash_changeset_post( $changeset_post->ID );
	}
}

/**
 * Filters changeset post data upon insert to ensure post_name is intact.
 *
 * This is needed to prevent the post_name from being dropped when the post is
 * transitioned into pending status by a contributor.
 *
 * @since 4.7.0
 *
 * @see wp_insert_post()
 *
 * @param array $post_data          An array of slashed post data.
 * @param array $supplied_post_data An array of sanitized, but otherwise unmodified post data.
 * @return array Filtered data.
 */
function _wp_customize_changeset_filter_insert_post_data( $post_data, $supplied_post_data ) {
	if ( isset( $post_data['post_type'] ) && 'customize_changeset' === $post_data['post_type'] ) {

		// Prevent post_name from being dropped, such as when contributor saves a changeset post as pending.
		if ( empty( $post_data['post_name'] ) && ! empty( $supplied_post_data['post_name'] ) ) {
			$post_data['post_name'] = $supplied_post_data['post_name'];
		}
	}
	return $post_data;
}

/**
 * Adds settings for the customize-loader script.
 *
 * @since 3.4.0
 */
function _wp_customize_loader_settings() {
	$admin_origin = parse_url( admin_url() );
	$home_origin  = parse_url( home_url() );
	$cross_domain = ( strtolower( $admin_origin['host'] ) != strtolower( $home_origin['host'] ) );

	$browser = array(
		'mobile' => wp_is_mobile(),
		'ios'    => wp_is_mobile() && preg_match( '/iPad|iPod|iPhone/', $_SERVER['HTTP_USER_AGENT'] ),
	);

	$settings = array(
		'url'           => esc_url( admin_url( 'customize.php' ) ),
		'isCrossDomain' => $cross_domain,
		'browser'       => $browser,
		'l10n'          => array(
			'saveAlert'       => __( 'The changes you made will be lost if you navigate away from this page.' ),
			'mainIframeTitle' => __( 'Customizer' ),
		),
	);

	$script = 'var _wpCustomizeLoaderSettings = ' . wp_json_encode( $settings ) . ';';

	$wp_scripts = wp_scripts();
	$data       = $wp_scripts->get_data( 'customize-loader', 'data' );
	if ( $data ) {
		$script = "$data\n$script";
	}

	$wp_scripts->add_data( 'customize-loader', 'data', $script );
}

/**
 * Returns a URL to load the Customizer.
 *
 * @since 3.4.0
 *
 * @param string $stylesheet Optional. Theme to customize. Defaults to active theme.
 *                           The theme's stylesheet will be urlencoded if necessary.
 * @return string
 */
function wp_customize_url( $stylesheet = '' ) {
	$url = admin_url( 'customize.php' );
	if ( $stylesheet ) {
		$url .= '?theme=' . urlencode( $stylesheet );
	}
	return esc_url( $url );
}

/**
 * Prints a script to check whether or not the Customizer is supported,
 * and apply either the no-customize-support or customize-support class
 * to the body.
 *
 * This function MUST be called inside the body tag.
 *
 * Ideally, call this function immediately after the body tag is opened.
 * This prevents a flash of unstyled content.
 *
 * It is also recommended that you add the "no-customize-support" class
 * to the body tag by default.
 *
 * @since 3.4.0
 * @since 4.7.0    Support for IE8 and below is explicitly removed via conditional comments.
 * @since 5.5.0    IE8 and older are no longer supported.
 * @since CP-2.0.0 XHTML is no longer supported.
 */
function wp_customize_support_script() {
	$admin_origin = parse_url( admin_url() );
	$home_origin  = parse_url( home_url() );
	$cross_domain = ( strtolower( $admin_origin['host'] ) != strtolower( $home_origin['host'] ) );
	?>
	<script>
		(function() {
			var request, b = document.body, c = 'className', cs = 'customize-support', rcs = new RegExp('(^|\\s+)(no-)?'+cs+'(\\s+|$)');

	<?php	if ( $cross_domain ) : ?>
			request = (function(){ var xhr = new XMLHttpRequest(); return ('withCredentials' in xhr); })();
	<?php	else : ?>
			request = true;
	<?php	endif; ?>

			b[c] = b[c].replace( rcs, ' ' );
			// The customizer requires postMessage and CORS (if the site is cross domain).
			b[c] += ( window.postMessage && request ? ' ' : ' no-' ) + cs;
		}());
	</script>
	<?php
}

/**
 * Whether the site is being previewed in the Customizer.
 *
 * @since 4.0.0
 *
 * @global WP_Customize_Manager $wp_customize Customizer instance.
 *
 * @return bool True if the site is being previewed in the Customizer, false otherwise.
 */
function is_customize_preview() {
	global $wp_customize;

	return ( $wp_customize instanceof WP_Customize_Manager ) && $wp_customize->is_preview();
}

/**
 * Makes sure that auto-draft posts get their post_date bumped or status changed
 * to draft to prevent premature garbage-collection.
 *
 * When a changeset is updated but remains an auto-draft, ensure the post_date
 * for the auto-draft posts remains the same so that it will be
 * garbage-collected at the same time by `wp_delete_auto_drafts()`. Otherwise,
 * if the changeset is updated to be a draft then update the posts
 * to have a far-future post_date so that they will never be garbage collected
 * unless the changeset post itself is deleted.
 *
 * When a changeset is updated to be a persistent draft or to be scheduled for
 * publishing, then transition any dependent auto-drafts to a draft status so
 * that they likewise will not be garbage-collected but also so that they can
 * be edited in the admin before publishing since there is not yet a post/page
 * editing flow in the Customizer. See #39752.
 *
 * @link https://core.trac.wordpress.org/ticket/39752
 *
 * @since 4.8.0
 * @access private
 * @see wp_delete_auto_drafts()
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string   $new_status Transition to this post status.
 * @param string   $old_status Previous post status.
 * @param \WP_Post $post       Post data.
 */
function _wp_keep_alive_customize_changeset_dependent_auto_drafts( $new_status, $old_status, $post ) {
	global $wpdb;
	unset( $old_status );

	// Short-circuit if not a changeset or if the changeset was published.
	if ( 'customize_changeset' !== $post->post_type || 'publish' === $new_status ) {
		return;
	}

	$data = json_decode( $post->post_content, true );
	if ( empty( $data['nav_menus_created_posts']['value'] ) ) {
		return;
	}

	/*
	 * Actually, in lieu of keeping alive, trash any customization drafts here if the changeset itself is
	 * getting trashed. This is needed because when a changeset transitions to a draft, then any of the
	 * dependent auto-draft post/page stubs will also get transitioned to customization drafts which
	 * are then visible in the WP Admin. We cannot wait for the deletion of the changeset in which
	 * _wp_delete_customize_changeset_dependent_auto_drafts() will be called, since they need to be
	 * trashed to remove from visibility immediately.
	 */
	if ( 'trash' === $new_status ) {
		foreach ( $data['nav_menus_created_posts']['value'] as $post_id ) {
			if ( ! empty( $post_id ) && 'draft' === get_post_status( $post_id ) ) {
				wp_trash_post( $post_id );
			}
		}
		return;
	}

	$post_args = array();
	if ( 'auto-draft' === $new_status ) {
		/*
		 * Keep the post date for the post matching the changeset
		 * so that it will not be garbage-collected before the changeset.
		 */
		$post_args['post_date'] = $post->post_date; // Note wp_delete_auto_drafts() only looks at this date.
	} else {
		/*
		 * Since the changeset no longer has an auto-draft (and it is not published)
		 * it is now a persistent changeset, a long-lived draft, and so any
		 * associated auto-draft posts should likewise transition into having a draft
		 * status. These drafts will be treated differently than regular drafts in
		 * that they will be tied to the given changeset. The publish meta box is
		 * replaced with a notice about how the post is part of a set of customized changes
		 * which will be published when the changeset is published.
		 */
		$post_args['post_status'] = 'draft';
	}

	foreach ( $data['nav_menus_created_posts']['value'] as $post_id ) {
		if ( empty( $post_id ) || 'auto-draft' !== get_post_status( $post_id ) ) {
			continue;
		}
		$wpdb->update(
			$wpdb->posts,
			$post_args,
			array( 'ID' => $post_id )
		);
		clean_post_cache( $post_id );
	}
}

/**
 * Creates the initial theme features when the 'setup_theme' action is fired.
 *
 * See {@see 'setup_theme'}.
 *
 * @since 5.5.0
 */
function create_initial_theme_features() {
	register_theme_feature(
		'align-wide',
		array(
			'description'  => __( 'Whether theme opts in to wide alignment CSS class.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'automatic-feed-links',
		array(
			'description'  => __( 'Whether posts and comments RSS feed links are added to head.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'custom-background',
		array(
			'description'  => __( 'Custom background if defined by the theme.' ),
			'type'         => 'object',
			'show_in_rest' => array(
				'schema' => array(
					'properties' => array(
						'default-image'      => array(
							'type'   => 'string',
							'format' => 'uri',
						),
						'default-preset'     => array(
							'type' => 'string',
							'enum' => array(
								'default',
								'fill',
								'fit',
								'repeat',
								'custom',
							),
						),
						'default-position-x' => array(
							'type' => 'string',
							'enum' => array(
								'left',
								'center',
								'right',
							),
						),
						'default-position-y' => array(
							'type' => 'string',
							'enum' => array(
								'left',
								'center',
								'right',
							),
						),
						'default-size'       => array(
							'type' => 'string',
							'enum' => array(
								'auto',
								'contain',
								'cover',
							),
						),
						'default-repeat'     => array(
							'type' => 'string',
							'enum' => array(
								'repeat-x',
								'repeat-y',
								'repeat',
								'no-repeat',
							),
						),
						'default-attachment' => array(
							'type' => 'string',
							'enum' => array(
								'scroll',
								'fixed',
							),
						),
						'default-color'      => array(
							'type' => 'string',
						),
					),
				),
			),
		)
	);
	register_theme_feature(
		'custom-header',
		array(
			'description'  => __( 'Custom header if defined by the theme.' ),
			'type'         => 'object',
			'show_in_rest' => array(
				'schema' => array(
					'properties' => array(
						'default-image'      => array(
							'type'   => 'string',
							'format' => 'uri',
						),
						'random-default'     => array(
							'type' => 'boolean',
						),
						'width'              => array(
							'type' => 'integer',
						),
						'height'             => array(
							'type' => 'integer',
						),
						'flex-height'        => array(
							'type' => 'boolean',
						),
						'flex-width'         => array(
							'type' => 'boolean',
						),
						'default-text-color' => array(
							'type' => 'string',
						),
						'header-text'        => array(
							'type' => 'boolean',
						),
						'uploads'            => array(
							'type' => 'boolean',
						),
						'video'              => array(
							'type' => 'boolean',
						),
					),
				),
			),
		)
	);
	register_theme_feature(
		'custom-logo',
		array(
			'type'         => 'object',
			'description'  => __( 'Custom logo if defined by the theme.' ),
			'show_in_rest' => array(
				'schema' => array(
					'properties' => array(
						'width'                => array(
							'type' => 'integer',
						),
						'height'               => array(
							'type' => 'integer',
						),
						'flex-width'           => array(
							'type' => 'boolean',
						),
						'flex-height'          => array(
							'type' => 'boolean',
						),
						'header-text'          => array(
							'type'  => 'array',
							'items' => array(
								'type' => 'string',
							),
						),
						'unlink-homepage-logo' => array(
							'type' => 'boolean',
						),
					),
				),
			),
		)
	);
	register_theme_feature(
		'customize-selective-refresh-widgets',
		array(
			'description'  => __( 'Whether the theme enables Selective Refresh for Widgets being managed with the Customizer.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'dark-editor-style',
		array(
			'description'  => __( 'Whether theme opts in to the dark editor style UI.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'disable-custom-colors',
		array(
			'description'  => __( 'Whether the theme disables custom colors.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'disable-custom-font-sizes',
		array(
			'description'  => __( 'Whether the theme disables custom font sizes.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'disable-custom-gradients',
		array(
			'description'  => __( 'Whether the theme disables custom gradients.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'disable-layout-styles',
		array(
			'description'  => __( 'Whether the theme disables generated layout styles.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'editor-color-palette',
		array(
			'type'         => 'array',
			'description'  => __( 'Custom color palette if defined by the theme.' ),
			'show_in_rest' => array(
				'schema' => array(
					'items' => array(
						'type'       => 'object',
						'properties' => array(
							'name'  => array(
								'type' => 'string',
							),
							'slug'  => array(
								'type' => 'string',
							),
							'color' => array(
								'type' => 'string',
							),
						),
					),
				),
			),
		)
	);
	register_theme_feature(
		'editor-font-sizes',
		array(
			'type'         => 'array',
			'description'  => __( 'Custom font sizes if defined by the theme.' ),
			'show_in_rest' => array(
				'schema' => array(
					'items' => array(
						'type'       => 'object',
						'properties' => array(
							'name' => array(
								'type' => 'string',
							),
							'size' => array(
								'type' => 'number',
							),
							'slug' => array(
								'type' => 'string',
							),
						),
					),
				),
			),
		)
	);
	register_theme_feature(
		'editor-gradient-presets',
		array(
			'type'         => 'array',
			'description'  => __( 'Custom gradient presets if defined by the theme.' ),
			'show_in_rest' => array(
				'schema' => array(
					'items' => array(
						'type'       => 'object',
						'properties' => array(
							'name'     => array(
								'type' => 'string',
							),
							'gradient' => array(
								'type' => 'string',
							),
							'slug'     => array(
								'type' => 'string',
							),
						),
					),
				),
			),
		)
	);
	register_theme_feature(
		'editor-styles',
		array(
			'description'  => __( 'Whether theme opts in to the editor styles CSS wrapper.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'html5',
		array(
			'type'         => 'array',
			'description'  => __( 'Allows use of HTML5 markup for search forms, comment forms, comment lists, gallery, and caption.' ),
			'show_in_rest' => array(
				'schema' => array(
					'items' => array(
						'type' => 'string',
						'enum' => array(
							'search-form',
							'comment-form',
							'comment-list',
							'gallery',
							'caption',
							'script',
							'style',
						),
					),
				),
			),
		)
	);
	register_theme_feature(
		'post-formats',
		array(
			'type'         => 'array',
			'description'  => __( 'Post formats supported.' ),
			'show_in_rest' => array(
				'name'             => 'formats',
				'schema'           => array(
					'items'   => array(
						'type' => 'string',
						'enum' => get_post_format_slugs(),
					),
					'default' => array( 'standard' ),
				),
				'prepare_callback' => static function ( $formats ) {
					$formats = is_array( $formats ) ? array_values( $formats[0] ) : array();
					$formats = array_merge( array( 'standard' ), $formats );

					return $formats;
				},
			),
		)
	);
	register_theme_feature(
		'post-thumbnails',
		array(
			'type'         => 'array',
			'description'  => __( 'The post types that support thumbnails or true if all post types are supported.' ),
			'show_in_rest' => array(
				'type'   => array( 'boolean', 'array' ),
				'schema' => array(
					'items' => array(
						'type' => 'string',
					),
				),
			),
		)
	);
	register_theme_feature(
		'responsive-embeds',
		array(
			'description'  => __( 'Whether the theme supports responsive embedded content.' ),
			'show_in_rest' => true,
		)
	);
	register_theme_feature(
		'title-tag',
		array(
			'description'  => __( 'Whether the theme can manage the document title tag.' ),
			'show_in_rest' => true,
		)
	);
}
