<?php
/**
 * These functions are needed to load Multisite.
 *
 * @since 3.0.0
 *
 * @package WordPress
 * @subpackage Multisite
 */

/**
 * Whether a subdomain configuration is enabled.
 *
 * @since 3.0.0
 *
 * @return bool True if subdomain configuration is enabled, false otherwise.
 */
function is_subdomain_install() {
	if ( defined( 'SUBDOMAIN_INSTALL' ) ) {
		return SUBDOMAIN_INSTALL;
	}

	return ( defined( 'VHOST' ) && 'yes' === VHOST );
}

/**
 * Returns array of network plugin files to be included in global scope.
 *
 * The default directory is wp-content/plugins. To change the default directory
 * manually, define `WP_PLUGIN_DIR` and `WP_PLUGIN_URL` in `wp-config.php`.
 *
 * @access private
 * @since 3.1.0
 *
 * @return string[] Array of absolute paths to files to include.
 */
function wp_get_active_network_plugins() {
	$active_plugins = (array) get_site_option( 'active_sitewide_plugins', array() );
	if ( empty( $active_plugins ) ) {
		return array();
	}

	$plugins        = array();
	$active_plugins = array_keys( $active_plugins );
	sort( $active_plugins );

	foreach ( $active_plugins as $plugin ) {
		if ( ! validate_file( $plugin )                     // $plugin must validate as file.
			&& '.php' === substr( $plugin, -4 )             // $plugin must end with '.php'.
			&& file_exists( WP_PLUGIN_DIR . '/' . $plugin ) // $plugin must exist.
			) {
			$plugins[] = WP_PLUGIN_DIR . '/' . $plugin;
		}
	}

	return $plugins;
}

/**
 * Checks status of current blog.
 *
 * Checks if the blog is deleted, inactive, archived, or spammed.
 *
 * Dies with a default message if the blog does not pass the check.
 *
 * To change the default message when a blog does not pass the check,
 * use the wp-content/blog-deleted.php, blog-inactive.php and
 * blog-suspended.php drop-ins.
 *
 * @since 3.0.0
 *
 * @return true|string Returns true on success, or drop-in file to include.
 */
function ms_site_check() {

	/**
	 * Filters checking the status of the current blog.
	 *
	 * @since 3.0.0
	 *
	 * @param bool|null $check Whether to skip the blog status check. Default null.
	 */
	$check = apply_filters( 'ms_site_check', null );
	if ( null !== $check ) {
		return true;
	}

	// Allow super admins to see blocked sites.
	if ( is_super_admin() ) {
		return true;
	}

	$blog = get_site();

	if ( '1' == $blog->deleted ) {
		if ( file_exists( WP_CONTENT_DIR . '/blog-deleted.php' ) ) {
			return WP_CONTENT_DIR . '/blog-deleted.php';
		} else {
			wp_die( __( 'This site is no longer available.' ), '', array( 'response' => 410 ) );
		}
	}

	if ( '2' == $blog->deleted ) {
		if ( file_exists( WP_CONTENT_DIR . '/blog-inactive.php' ) ) {
			return WP_CONTENT_DIR . '/blog-inactive.php';
		} else {
			$admin_email = str_replace( '@', ' AT ', get_site_option( 'admin_email', 'support@' . get_network()->domain ) );
			wp_die(
				sprintf(
					/* translators: %s: Admin email link. */
					__( 'This site has not been activated yet. If you are having problems activating your site, please contact %s.' ),
					sprintf( '%1$s', $admin_email )
				)
			);
		}
	}

	if ( '1' == $blog->archived || '1' == $blog->spam ) {
		if ( file_exists( WP_CONTENT_DIR . '/blog-suspended.php' ) ) {
			return WP_CONTENT_DIR . '/blog-suspended.php';
		} else {
			wp_die( __( 'This site has been archived or suspended.' ), '', array( 'response' => 410 ) );
		}
	}

	return true;
}

/**
 * Retrieve the closest matching network for a domain and path.
 *
 * @since 3.9.0
 *
 * @internal In 4.4.0, converted to a wrapper for WP_Network::get_by_path()
 *
 * @param string   $domain   Domain to check.
 * @param string   $path     Path to check.
 * @param int|null $segments Path segments to use. Defaults to null, or the full path.
 * @return WP_Network|false Network object if successful. False when no network is found.
 */
function get_network_by_path( $domain, $path, $segments = null ) {
	return WP_Network::get_by_path( $domain, $path, $segments );
}

/**
 * Retrieves the closest matching site object by its domain and path.
 *
 * This will not necessarily return an exact match for a domain and path. Instead, it
 * breaks the domain and path into pieces that are then used to match the closest
 * possibility from a query.
 *
 * The intent of this method is to match a site object during bootstrap for a
 * requested site address
 *
 * @since 3.9.0
 * @since 4.7.0 Updated to always return a `WP_Site` object.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string   $domain   Domain to check.
 * @param string   $path     Path to check.
 * @param int|null $segments Path segments to use. Defaults to null, or the full path.
 * @return WP_Site|false Site object if successful. False when no site is found.
 */
function get_site_by_path( $domain, $path, $segments = null ) {
	$path_segments = array_filter( explode( '/', trim( $path, '/' ) ) );

	/**
	 * Filters the number of path segments to consider when searching for a site.
	 *
	 * @since 3.9.0
	 *
	 * @param int|null $segments The number of path segments to consider. WordPress by default looks at
	 *                           one path segment following the network path. The function default of
	 *                           null only makes sense when you know the requested path should match a site.
	 * @param string   $domain   The requested domain.
	 * @param string   $path     The requested path, in full.
	 */
	$segments = apply_filters( 'site_by_path_segments_count', $segments, $domain, $path );

	if ( null !== $segments && count( $path_segments ) > $segments ) {
		$path_segments = array_slice( $path_segments, 0, $segments );
	}

	$paths = array();

	while ( count( $path_segments ) ) {
		$paths[] = '/' . implode( '/', $path_segments ) . '/';
		array_pop( $path_segments );
	}

	$paths[] = '/';

	/**
	 * Determine a site by its domain and path.
	 *
	 * This allows one to short-circuit the default logic, perhaps by
	 * replacing it with a routine that is more optimal for your setup.
	 *
	 * Return null to avoid the short-circuit. Return false if no site
	 * can be found at the requested domain and path. Otherwise, return
	 * a site object.
	 *
	 * @since 3.9.0
	 *
	 * @param null|false|WP_Site $site     Site value to return by path. Default null
	 *                                     to continue retrieving the site.
	 * @param string             $domain   The requested domain.
	 * @param string             $path     The requested path, in full.
	 * @param int|null           $segments The suggested number of paths to consult.
	 *                                     Default null, meaning the entire path was to be consulted.
	 * @param string[]           $paths    The paths to search for, based on $path and $segments.
	 */
	$pre = apply_filters( 'pre_get_site_by_path', null, $domain, $path, $segments, $paths );
	if ( null !== $pre ) {
		if ( false !== $pre && ! $pre instanceof WP_Site ) {
			$pre = new WP_Site( $pre );
		}
		return $pre;
	}

	/*
	 * @todo
	 * Caching, etc. Consider alternative optimization routes,
	 * perhaps as an opt-in for plugins, rather than using the pre_* filter.
	 * For example: The segments filter can expand or ignore paths.
	 * If persistent caching is enabled, we could query the DB for a path <> '/'
	 * then cache whether we can just always ignore paths.
	 */

	// Either www or non-www is supported, not both. If a www domain is requested,
	// query for both to provide the proper redirect.
	$domains = array( $domain );
	if ( 'www.' === substr( $domain, 0, 4 ) ) {
		$domains[] = substr( $domain, 4 );
	}

	$args = array(
		'number'                 => 1,
		'update_site_meta_cache' => false,
	);

	if ( count( $domains ) > 1 ) {
		$args['domain__in']               = $domains;
		$args['orderby']['domain_length'] = 'DESC';
	} else {
		$args['domain'] = array_shift( $domains );
	}

	if ( count( $paths ) > 1 ) {
		$args['path__in']               = $paths;
		$args['orderby']['path_length'] = 'DESC';
	} else {
		$args['path'] = array_shift( $paths );
	}

	$result = get_sites( $args );
	$site   = array_shift( $result );

	if ( $site ) {
		return $site;
	}

	return false;
}

/**
 * Identifies the network and site of a requested domain and path and populates the
 * corresponding network and site global objects as part of the multisite bootstrap process.
 *
 * Prior to 4.6.0, this was a procedural block in `ms-settings.php`. It was wrapped into
 * a function to facilitate unit tests. It should not be used outside of core.
 *
 * Usually, it's easier to query the site first, which then declares its network.
 * In limited situations, we either can or must find the network first.
 *
 * If a network and site are found, a `true` response will be returned so that the
 * request can continue.
 *
 * If neither a network or site is found, `false` or a URL string will be returned
 * so that either an error can be shown or a redirect can occur.
 *
 * @since 4.6.0
 * @access private
 *
 * @global WP_Network $current_site The current network.
 * @global WP_Site    $current_blog The current site.
 *
 * @param string $domain    The requested domain.
 * @param string $path      The requested path.
 * @param bool   $subdomain Optional. Whether a subdomain (true) or subdirectory (false) configuration.
 *                          Default false.
 * @return bool|string True if bootstrap successfully populated `$current_blog` and `$current_site`.
 *                     False if bootstrap could not be properly completed.
 *                     Redirect URL if parts exist, but the request as a whole can not be fulfilled.
 */
function ms_load_current_site_and_network( $domain, $path, $subdomain = false ) {
	global $current_site, $current_blog;

	// If the network is defined in wp-config.php, we can simply use that.
	if ( defined( 'DOMAIN_CURRENT_SITE' ) && defined( 'PATH_CURRENT_SITE' ) ) {
		$current_site         = new stdClass;
		$current_site->id     = defined( 'SITE_ID_CURRENT_SITE' ) ? SITE_ID_CURRENT_SITE : 1;
		$current_site->domain = DOMAIN_CURRENT_SITE;
		$current_site->path   = PATH_CURRENT_SITE;
		if ( defined( 'BLOG_ID_CURRENT_SITE' ) ) {
			$current_site->blog_id = BLOG_ID_CURRENT_SITE;
		} elseif ( defined( 'BLOGID_CURRENT_SITE' ) ) { // Deprecated.
			$current_site->blog_id = BLOGID_CURRENT_SITE;
		}

		if ( 0 === strcasecmp( $current_site->domain, $domain ) && 0 === strcasecmp( $current_site->path, $path ) ) {
			$current_blog = get_site_by_path( $domain, $path );
		} elseif ( '/' !== $current_site->path && 0 === strcasecmp( $current_site->domain, $domain ) && 0 === stripos( $path, $current_site->path ) ) {
			// If the current network has a path and also matches the domain and path of the request,
			// we need to look for a site using the first path segment following the network's path.
			$current_blog = get_site_by_path( $domain, $path, 1 + count( explode( '/', trim( $current_site->path, '/' ) ) ) );
		} else {
			// Otherwise, use the first path segment (as usual).
			$current_blog = get_site_by_path( $domain, $path, 1 );
		}
	} elseif ( ! $subdomain ) {
		/*
		 * A "subdomain" installation can be re-interpreted to mean "can support any domain".
		 * If we're not dealing with one of these installations, then the important part is determining
		 * the network first, because we need the network's path to identify any sites.
		 */
		$current_site = wp_cache_get( 'current_network', 'site-options' );
		if ( ! $current_site ) {
			// Are there even two networks installed?
			$networks = get_networks( array( 'number' => 2 ) );
			if ( count( $networks ) === 1 ) {
				$current_site = array_shift( $networks );
				wp_cache_add( 'current_network', $current_site, 'site-options' );
			} elseif ( empty( $networks ) ) {
				// A network not found hook should fire here.
				return false;
			}
		}

		if ( empty( $current_site ) ) {
			$current_site = WP_Network::get_by_path( $domain, $path, 1 );
		}

		if ( empty( $current_site ) ) {
			/**
			 * Fires when a network cannot be found based on the requested domain and path.
			 *
			 * At the time of this action, the only recourse is to redirect somewhere
			 * and exit. If you want to declare a particular network, do so earlier.
			 *
			 * @since 4.4.0
			 *
			 * @param string $domain       The domain used to search for a network.
			 * @param string $path         The path used to search for a path.
			 */
			do_action( 'ms_network_not_found', $domain, $path );

			return false;
		} elseif ( $path === $current_site->path ) {
			$current_blog = get_site_by_path( $domain, $path );
		} else {
			// Search the network path + one more path segment (on top of the network path).
			$current_blog = get_site_by_path( $domain, $path, substr_count( $current_site->path, '/' ) );
		}
	} else {
		// Find the site by the domain and at most the first path segment.
		$current_blog = get_site_by_path( $domain, $path, 1 );
		if ( $current_blog ) {
			$current_site = WP_Network::get_instance( $current_blog->site_id ? $current_blog->site_id : 1 );
		} else {
			// If you don't have a site with the same domain/path as a network, you're pretty screwed, but:
			$current_site = WP_Network::get_by_path( $domain, $path, 1 );
		}
	}

	// The network declared by the site trumps any constants.
	if ( $current_blog && $current_blog->site_id != $current_site->id ) {
		$current_site = WP_Network::get_instance( $current_blog->site_id );
	}

	// No network has been found, bail.
	if ( empty( $current_site ) ) {
		/** This action is documented in wp-includes/ms-settings.php */
		do_action( 'ms_network_not_found', $domain, $path );

		return false;
	}

	// During activation of a new subdomain, the requested site does not yet exist.
	if ( empty( $current_blog ) && wp_installing() ) {
		$current_blog          = new stdClass;
		$current_blog->blog_id = 1;
		$blog_id               = 1;
		$current_blog->public  = 1;
	}

	// No site has been found, bail.
	if ( empty( $current_blog ) ) {
		// We're going to redirect to the network URL, with some possible modifications.
		$scheme      = is_ssl() ? 'https' : 'http';
		$destination = "$scheme://{$current_site->domain}{$current_site->path}";

		/**
		 * Fires when a network can be determined but a site cannot.
		 *
		 * At the time of this action, the only recourse is to redirect somewhere
		 * and exit. If you want to declare a particular site, do so earlier.
		 *
		 * @since 3.9.0
		 *
		 * @param object $current_site The network that had been determined.
		 * @param string $domain       The domain used to search for a site.
		 * @param string $path         The path used to search for a site.
		 */
		do_action( 'ms_site_not_found', $current_site, $domain, $path );

		if ( $subdomain && ! defined( 'NOBLOGREDIRECT' ) ) {
			// For a "subdomain" installation, redirect to the signup form specifically.
			$destination .= 'wp-signup.php?new=' . str_replace( '.' . $current_site->domain, '', $domain );
		} elseif ( $subdomain ) {
			/*
			 * For a "subdomain" installation, the NOBLOGREDIRECT constant
			 * can be used to avoid a redirect to the signup form.
			 * Using the ms_site_not_found action is preferred to the constant.
			 */
			if ( '%siteurl%' !== NOBLOGREDIRECT ) {
				$destination = NOBLOGREDIRECT;
			}
		} elseif ( 0 === strcasecmp( $current_site->domain, $domain ) ) {
			/*
			 * If the domain we were searching for matches the network's domain,
			 * it's no use redirecting back to ourselves -- it'll cause a loop.
			 * As we couldn't find a site, we're simply not installed.
			 */
			return false;
		}

		return $destination;
	}

	// Figure out the current network's main site.
	if ( empty( $current_site->blog_id ) ) {
		$current_site->blog_id = get_main_site_id( $current_site->id );
	}

	return true;
}

/**
 * Displays a failure message.
 *
 * Used when a blog's tables do not exist. Checks for a missing $wpdb->site table as well.
 *
 * @access private
 * @since 3.0.0
 * @since 4.4.0 The `$domain` and `$path` parameters were added.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string $domain The requested domain for the error to reference.
 * @param string $path   The requested path for the error to reference.
 */
function ms_not_installed( $domain, $path ) {
	global $wpdb;

	if ( ! is_admin() ) {
		dead_db();
	}

	wp_load_translations_early();

	$title = __( 'Error establishing a database connection' );

	$msg   = '
' . $title . '
';
	$msg  .= '
' . __( 'If your site does not display, please contact the owner of this network.' ) . '';
	$msg  .= ' ' . __( 'If you are the owner of this network please check that MySQL is running properly and all tables are error free.' ) . '
';
	$query = $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $wpdb->site ) );
	if ( ! $wpdb->get_var( $query ) ) {
		$msg .= '
' . sprintf(
			/* translators: %s: Table name. */
			__( 'Database tables are missing. This means that MySQL is not running, WordPress was not installed properly, or someone deleted %s. You really should look at your database now.' ),
			'' . $wpdb->site . ''
		) . '
';
	} else {
		$msg .= '
' . sprintf(
			/* translators: 1: Site URL, 2: Table name, 3: Database name. */
			__( 'Could not find site %1$s. Searched for table %2$s in database %3$s. Is that right?' ),
			'' . rtrim( $domain . $path, '/' ) . '',
			'' . $wpdb->blogs . '',
			'' . DB_NAME . ''
		) . '
';
	}
	$msg .= '
' . __( 'What do I do now?' ) . ' ';
	$msg .= sprintf(
		/* translators: %s: Documentation URL. */
		__( 'Read the Debugging a WordPress Network article. Some of the suggestions there may help you figure out what went wrong.' ),
		__( 'https://wordpress.org/support/article/debugging-a-wordpress-network/' )
	);
	$msg .= ' ' . __( 'If you’re still stuck with this message, then check that your database contains the following tables:' ) . '

';
	foreach ( $wpdb->tables( 'global' ) as $t => $table ) {
		if ( 'sitecategories' === $t ) {
			continue;
		}
		$msg .= '
' . $table . '
';
	}
	$msg .= '
';

	wp_die( $msg, $title, array( 'response' => 500 ) );
}

/**
 * This deprecated function formerly set the site_name property of the $current_site object.
 *
 * This function simply returns the object, as before.
 * The bootstrap takes care of setting site_name.
 *
 * @access private
 * @since 3.0.0
 * @deprecated 3.9.0 Use get_current_site() instead.
 *
 * @param object $current_site
 * @return object
 */
function get_current_site_name( $current_site ) {
	_deprecated_function( __FUNCTION__, '3.9.0', 'get_current_site()' );
	return $current_site;
}

/**
 * This deprecated function managed much of the site and network loading in multisite.
 *
 * The current bootstrap code is now responsible for parsing the site and network load as
 * well as setting the global $current_site object.
 *
 * @access private
 * @since 3.0.0
 * @deprecated 3.9.0
 *
 * @global object $current_site
 *
 * @return object
 */
function wpmu_current_site() {
	global $current_site;
	_deprecated_function( __FUNCTION__, '3.9.0' );
	return $current_site;
}

/**
 * Retrieve an object containing information about the requested network.
 *
 * @since 3.9.0
 * @deprecated 4.7.0 Use `get_network()`
 * @see get_network()
 *
 * @internal In 4.6.0, converted to use get_network()
 *
 * @param object|int $network The network's database row or ID.
 * @return WP_Network|false Object containing network information if found, false if not.
 */
function wp_get_network( $network ) {
	_deprecated_function( __FUNCTION__, '4.7.0', 'get_network()' );

	$network = get_network( $network );
	if ( null === $network ) {
		return false;
	}

	return $network;
}


<?php
/**
 * Network API
 *
 * @package WordPress
 * @subpackage Multisite
 * @since 5.1.0
 */

/**
 * Retrieves network data given a network ID or network object.
 *
 * Network data will be cached and returned after being passed through a filter.
 * If the provided network is empty, the current network global will be used.
 *
 * @since 4.6.0
 *
 * @global WP_Network $current_site
 *
 * @param WP_Network|int|null $network Optional. Network to retrieve. Default is the current network.
 * @return WP_Network|null The network object or null if not found.
 */
function get_network( $network = null ) {
	global $current_site;
	if ( empty( $network ) && isset( $current_site ) ) {
		$network = $current_site;
	}

	if ( $network instanceof WP_Network ) {
		$_network = $network;
	} elseif ( is_object( $network ) ) {
		$_network = new WP_Network( $network );
	} else {
		$_network = WP_Network::get_instance( $network );
	}

	if ( ! $_network ) {
		return null;
	}

	/**
	 * Fires after a network is retrieved.
	 *
	 * @since 4.6.0
	 *
	 * @param WP_Network $_network Network data.
	 */
	$_network = apply_filters( 'get_network', $_network );

	return $_network;
}

/**
 * Retrieves a list of networks.
 *
 * @since 4.6.0
 *
 * @param string|array $args Optional. Array or string of arguments. See WP_Network_Query::parse_query()
 *                           for information on accepted arguments. Default empty array.
 * @return array|int List of WP_Network objects, a list of network IDs when 'fields' is set to 'ids',
 *                   or the number of networks when 'count' is passed as a query var.
 */
function get_networks( $args = array() ) {
	$query = new WP_Network_Query();

	return $query->query( $args );
}

/**
 * Removes a network from the object cache.
 *
 * @since 4.6.0
 *
 * @global bool $_wp_suspend_cache_invalidation
 *
 * @param int|array $ids Network ID or an array of network IDs to remove from cache.
 */
function clean_network_cache( $ids ) {
	global $_wp_suspend_cache_invalidation;

	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
		return;
	}

	foreach ( (array) $ids as $id ) {
		wp_cache_delete( $id, 'networks' );

		/**
		 * Fires immediately after a network has been removed from the object cache.
		 *
		 * @since 4.6.0
		 *
		 * @param int $id Network ID.
		 */
		do_action( 'clean_network_cache', $id );
	}

	wp_cache_set( 'last_changed', microtime(), 'networks' );
}

/**
 * Updates the network cache of given networks.
 *
 * Will add the networks in $networks to the cache. If network ID already exists
 * in the network cache then it will not be updated. The network is added to the
 * cache using the network group with the key using the ID of the networks.
 *
 * @since 4.6.0
 *
 * @param array $networks Array of network row objects.
 */
function update_network_cache( $networks ) {
	foreach ( (array) $networks as $network ) {
		wp_cache_add( $network->id, $network, 'networks' );
	}
}

/**
 * Adds any networks from the given IDs to the cache that do not already exist in cache.
 *
 * @since 4.6.0
 * @access private
 *
 * @see update_network_cache()
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $network_ids Array of network IDs.
 */
function _prime_network_caches( $network_ids ) {
	global $wpdb;

	$non_cached_ids = _get_non_cached_ids( $network_ids, 'networks' );
	if ( ! empty( $non_cached_ids ) ) {
		$fresh_networks = $wpdb->get_results( sprintf( "SELECT $wpdb->site.* FROM $wpdb->site WHERE id IN (%s)", join( ',', array_map( 'intval', $non_cached_ids ) ) ) ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared

		update_network_cache( $fresh_networks );
	}
}


<?php
/**
 * Used to set up and fix common variables and include
 * the Multisite procedural and class library.
 *
 * Allows for some configuration in wp-config.php (see ms-default-constants.php)
 *
 * @package WordPress
 * @subpackage Multisite
 * @since 3.0.0
 */

/**
 * Objects representing the current network and current site.
 *
 * These may be populated through a custom `sunrise.php`. If not, then this
 * file will attempt to populate them based on the current request.
 *
 * @global WP_Network $current_site The current network.
 * @global object     $current_blog The current site.
 * @global string     $domain       Deprecated. The domain of the site found on load.
 *                                  Use `get_site()->domain` instead.
 * @global string     $path         Deprecated. The path of the site found on load.
 *                                  Use `get_site()->path` instead.
 * @global int        $site_id      Deprecated. The ID of the network found on load.
 *                                  Use `get_current_network_id()` instead.
 * @global bool       $public       Deprecated. Whether the site found on load is public.
 *                                  Use `get_site()->public` instead.
 *
 * @since 3.0.0
 */
global $current_site, $current_blog, $domain, $path, $site_id, $public;

/** WP_Network class */
require_once ABSPATH . WPINC . '/class-wp-network.php';

/** WP_Site class */
require_once ABSPATH . WPINC . '/class-wp-site.php';

/** Multisite loader */
require_once ABSPATH . WPINC . '/ms-load.php';

/** Default Multisite constants */
require_once ABSPATH . WPINC . '/ms-default-constants.php';

if ( defined( 'SUNRISE' ) ) {
	include_once WP_CONTENT_DIR . '/sunrise.php';
}

/** Check for and define SUBDOMAIN_INSTALL and the deprecated VHOST constant. */
ms_subdomain_constants();

// This block will process a request if the current network or current site objects
// have not been populated in the global scope through something like `sunrise.php`.
if ( ! isset( $current_site ) || ! isset( $current_blog ) ) {

	$domain = strtolower( stripslashes( $_SERVER['HTTP_HOST'] ) );
	if ( ':80' === substr( $domain, -3 ) ) {
		$domain               = substr( $domain, 0, -3 );
		$_SERVER['HTTP_HOST'] = substr( $_SERVER['HTTP_HOST'], 0, -3 );
	} elseif ( ':443' === substr( $domain, -4 ) ) {
		$domain               = substr( $domain, 0, -4 );
		$_SERVER['HTTP_HOST'] = substr( $_SERVER['HTTP_HOST'], 0, -4 );
	}

	$path = stripslashes( $_SERVER['REQUEST_URI'] );
	if ( is_admin() ) {
		$path = preg_replace( '#(.*)/wp-admin/.*#', '$1/', $path );
	}
	list( $path ) = explode( '?', $path );

	$bootstrap_result = ms_load_current_site_and_network( $domain, $path, is_subdomain_install() );

	if ( true === $bootstrap_result ) {
		// `$current_blog` and `$current_site are now populated.
	} elseif ( false === $bootstrap_result ) {
		ms_not_installed( $domain, $path );
	} else {
		header( 'Location: ' . $bootstrap_result );
		exit;
	}
	unset( $bootstrap_result );

	$blog_id = $current_blog->blog_id;
	$public  = $current_blog->public;

	if ( empty( $current_blog->site_id ) ) {
		// This dates to [MU134] and shouldn't be relevant anymore,
		// but it could be possible for arguments passed to insert_blog() etc.
		$current_blog->site_id = 1;
	}

	$site_id = $current_blog->site_id;
	wp_load_core_site_options( $site_id );
}

$wpdb->set_prefix( $table_prefix, false ); // $table_prefix can be set in sunrise.php.
$wpdb->set_blog_id( $current_blog->blog_id, $current_blog->site_id );
$table_prefix       = $wpdb->get_blog_prefix();
$_wp_switched_stack = array();
$switched           = false;

// Need to init cache again after blog_id is set.
wp_start_object_cache();

if ( ! $current_site instanceof WP_Network ) {
	$current_site = new WP_Network( $current_site );
}

if ( ! $current_blog instanceof WP_Site ) {
	$current_blog = new WP_Site( $current_blog );
}

// Define upload directory constants.
ms_upload_constants();

/**
 * Fires after the current site and network have been detected and loaded
 * in multisite's bootstrap.
 *
 * @since 4.6.0
 */
do_action( 'ms_loaded' );


<?php
/**
 * Site API
 *
 * @package WordPress
 * @subpackage Multisite
 * @since 5.1.0
 */

/**
 * Inserts a new site into the database.
 *
 * @since 5.1.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $data {
 *     Data for the new site that should be inserted.
 *
 *     @type string $domain       Site domain. Default empty string.
 *     @type string $path         Site path. Default '/'.
 *     @type int    $network_id   The site's network ID. Default is the current network ID.
 *     @type string $registered   When the site was registered, in SQL datetime format. Default is
 *                                the current time.
 *     @type string $last_updated When the site was last updated, in SQL datetime format. Default is
 *                                the value of $registered.
 *     @type int    $public       Whether the site is public. Default 1.
 *     @type int    $archived     Whether the site is archived. Default 0.
 *     @type int    $mature       Whether the site is mature. Default 0.
 *     @type int    $spam         Whether the site is spam. Default 0.
 *     @type int    $deleted      Whether the site is deleted. Default 0.
 *     @type int    $lang_id      The site's language ID. Currently unused. Default 0.
 *     @type int    $user_id      User ID for the site administrator. Passed to the
 *                                `wp_initialize_site` hook.
 *     @type string $title        Site title. Default is 'Site %d' where %d is the site ID. Passed
 *                                to the `wp_initialize_site` hook.
 *     @type array  $options      Custom option $key => $value pairs to use. Default empty array. Passed
 *                                to the `wp_initialize_site` hook.
 *     @type array  $meta         Custom site metadata $key => $value pairs to use. Default empty array.
 *                                Passed to the `wp_initialize_site` hook.
 * }
 * @return int|WP_Error The new site's ID on success, or error object on failure.
 */
function wp_insert_site( array $data ) {
	global $wpdb;

	$now = current_time( 'mysql', true );

	$defaults = array(
		'domain'       => '',
		'path'         => '/',
		'network_id'   => get_current_network_id(),
		'registered'   => $now,
		'last_updated' => $now,
		'public'       => 1,
		'archived'     => 0,
		'mature'       => 0,
		'spam'         => 0,
		'deleted'      => 0,
		'lang_id'      => 0,
	);

	$prepared_data = wp_prepare_site_data( $data, $defaults );
	if ( is_wp_error( $prepared_data ) ) {
		return $prepared_data;
	}

	if ( false === $wpdb->insert( $wpdb->blogs, $prepared_data ) ) {
		return new WP_Error( 'db_insert_error', __( 'Could not insert site into the database.' ), $wpdb->last_error );
	}

	$site_id = (int) $wpdb->insert_id;

	clean_blog_cache( $site_id );

	$new_site = get_site( $site_id );

	if ( ! $new_site ) {
		return new WP_Error( 'get_site_error', __( 'Could not retrieve site data.' ) );
	}

	/**
	 * Fires once a site has been inserted into the database.
	 *
	 * @since 5.1.0
	 *
	 * @param WP_Site $new_site New site object.
	 */
	do_action( 'wp_insert_site', $new_site );

	// Extract the passed arguments that may be relevant for site initialization.
	$args = array_diff_key( $data, $defaults );
	if ( isset( $args['site_id'] ) ) {
		unset( $args['site_id'] );
	}

	/**
	 * Fires when a site's initialization routine should be executed.
	 *
	 * @since 5.1.0
	 *
	 * @param WP_Site $new_site New site object.
	 * @param array   $args     Arguments for the initialization.
	 */
	do_action( 'wp_initialize_site', $new_site, $args );

	// Only compute extra hook parameters if the deprecated hook is actually in use.
	if ( has_action( 'wpmu_new_blog' ) ) {
		$user_id = ! empty( $args['user_id'] ) ? $args['user_id'] : 0;
		$meta    = ! empty( $args['options'] ) ? $args['options'] : array();

		// WPLANG was passed with `$meta` to the `wpmu_new_blog` hook prior to 5.1.0.
		if ( ! array_key_exists( 'WPLANG', $meta ) ) {
			$meta['WPLANG'] = get_network_option( $new_site->network_id, 'WPLANG' );
		}

		// Rebuild the data expected by the `wpmu_new_blog` hook prior to 5.1.0 using allowed keys.
		// The `$allowed_data_fields` matches the one used in `wpmu_create_blog()`.
		$allowed_data_fields = array( 'public', 'archived', 'mature', 'spam', 'deleted', 'lang_id' );
		$meta                = array_merge( array_intersect_key( $data, array_flip( $allowed_data_fields ) ), $meta );

		/**
		 * Fires immediately after a new site is created.
		 *
		 * @since MU (3.0.0)
		 * @deprecated 5.1.0 Use {@see 'wp_insert_site'} instead.
		 *
		 * @param int    $site_id    Site ID.
		 * @param int    $user_id    User ID.
		 * @param string $domain     Site domain.
		 * @param string $path       Site path.
		 * @param int    $network_id Network ID. Only relevant on multi-network installations.
		 * @param array  $meta       Meta data. Used to set initial site options.
		 */
		do_action_deprecated(
			'wpmu_new_blog',
			array( $new_site->id, $user_id, $new_site->domain, $new_site->path, $new_site->network_id, $meta ),
			'5.1.0',
			'wp_insert_site'
		);
	}

	return (int) $new_site->id;
}

/**
 * Updates a site in the database.
 *
 * @since 5.1.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int   $site_id ID of the site that should be updated.
 * @param array $data    Site data to update. See {@see wp_insert_site()} for the list of supported keys.
 * @return int|WP_Error The updated site's ID on success, or error object on failure.
 */
function wp_update_site( $site_id, array $data ) {
	global $wpdb;

	if ( empty( $site_id ) ) {
		return new WP_Error( 'site_empty_id', __( 'Site ID must not be empty.' ) );
	}

	$old_site = get_site( $site_id );
	if ( ! $old_site ) {
		return new WP_Error( 'site_not_exist', __( 'Site does not exist.' ) );
	}

	$defaults                 = $old_site->to_array();
	$defaults['network_id']   = (int) $defaults['site_id'];
	$defaults['last_updated'] = current_time( 'mysql', true );
	unset( $defaults['blog_id'], $defaults['site_id'] );

	$data = wp_prepare_site_data( $data, $defaults, $old_site );
	if ( is_wp_error( $data ) ) {
		return $data;
	}

	if ( false === $wpdb->update( $wpdb->blogs, $data, array( 'blog_id' => $old_site->id ) ) ) {
		return new WP_Error( 'db_update_error', __( 'Could not update site in the database.' ), $wpdb->last_error );
	}

	clean_blog_cache( $old_site );

	$new_site = get_site( $old_site->id );

	/**
	 * Fires once a site has been updated in the database.
	 *
	 * @since 5.1.0
	 *
	 * @param WP_Site $new_site New site object.
	 * @param WP_Site $old_site Old site object.
	 */
	do_action( 'wp_update_site', $new_site, $old_site );

	return (int) $new_site->id;
}

/**
 * Deletes a site from the database.
 *
 * @since 5.1.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int $site_id ID of the site that should be deleted.
 * @return WP_Site|WP_Error The deleted site object on success, or error object on failure.
 */
function wp_delete_site( $site_id ) {
	global $wpdb;

	if ( empty( $site_id ) ) {
		return new WP_Error( 'site_empty_id', __( 'Site ID must not be empty.' ) );
	}

	$old_site = get_site( $site_id );
	if ( ! $old_site ) {
		return new WP_Error( 'site_not_exist', __( 'Site does not exist.' ) );
	}

	$errors = new WP_Error();

	/**
	 * Fires before a site should be deleted from the database.
	 *
	 * Plugins should amend the `$errors` object via its `WP_Error::add()` method. If any errors
	 * are present, the site will not be deleted.
	 *
	 * @since 5.1.0
	 *
	 * @param WP_Error $errors   Error object to add validation errors to.
	 * @param WP_Site  $old_site The site object to be deleted.
	 */
	do_action( 'wp_validate_site_deletion', $errors, $old_site );

	if ( ! empty( $errors->errors ) ) {
		return $errors;
	}

	/**
	 * Fires before a site is deleted.
	 *
	 * @since MU (3.0.0)
	 * @deprecated 5.1.0
	 *
	 * @param int  $site_id The site ID.
	 * @param bool $drop    True if site's table should be dropped. Default false.
	 */
	do_action_deprecated( 'delete_blog', array( $old_site->id, true ), '5.1.0' );

	/**
	 * Fires when a site's uninitialization routine should be executed.
	 *
	 * @since 5.1.0
	 *
	 * @param WP_Site $old_site Deleted site object.
	 */
	do_action( 'wp_uninitialize_site', $old_site );

	if ( is_site_meta_supported() ) {
		$blog_meta_ids = $wpdb->get_col( $wpdb->prepare( "SELECT meta_id FROM $wpdb->blogmeta WHERE blog_id = %d ", $old_site->id ) );
		foreach ( $blog_meta_ids as $mid ) {
			delete_metadata_by_mid( 'blog', $mid );
		}
	}

	if ( false === $wpdb->delete( $wpdb->blogs, array( 'blog_id' => $old_site->id ) ) ) {
		return new WP_Error( 'db_delete_error', __( 'Could not delete site from the database.' ), $wpdb->last_error );
	}

	clean_blog_cache( $old_site );

	/**
	 * Fires once a site has been deleted from the database.
	 *
	 * @since 5.1.0
	 *
	 * @param WP_Site $old_site Deleted site object.
	 */
	do_action( 'wp_delete_site', $old_site );

	/**
	 * Fires after the site is deleted from the network.
	 *
	 * @since 4.8.0
	 * @deprecated 5.1.0
	 *
	 * @param int  $site_id The site ID.
	 * @param bool $drop    True if site's tables should be dropped. Default false.
	 */
	do_action_deprecated( 'deleted_blog', array( $old_site->id, true ), '5.1.0' );

	return $old_site;
}

/**
 * Retrieves site data given a site ID or site object.
 *
 * Site data will be cached and returned after being passed through a filter.
 * If the provided site is empty, the current site global will be used.
 *
 * @since 4.6.0
 *
 * @param WP_Site|int|null $site Optional. Site to retrieve. Default is the current site.
 * @return WP_Site|null The site object or null if not found.
 */
function get_site( $site = null ) {
	if ( empty( $site ) ) {
		$site = get_current_blog_id();
	}

	if ( $site instanceof WP_Site ) {
		$_site = $site;
	} elseif ( is_object( $site ) ) {
		$_site = new WP_Site( $site );
	} else {
		$_site = WP_Site::get_instance( $site );
	}

	if ( ! $_site ) {
		return null;
	}

	/**
	 * Fires after a site is retrieved.
	 *
	 * @since 4.6.0
	 *
	 * @param WP_Site $_site Site data.
	 */
	$_site = apply_filters( 'get_site', $_site );

	return $_site;
}

/**
 * Adds any sites from the given IDs to the cache that do not already exist in cache.
 *
 * @since 4.6.0
 * @since 5.1.0 Introduced the `$update_meta_cache` parameter.
 * @access private
 *
 * @see update_site_cache()
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param array $ids               ID list.
 * @param bool  $update_meta_cache Optional. Whether to update the meta cache. Default true.
 */
function _prime_site_caches( $ids, $update_meta_cache = true ) {
	global $wpdb;

	$non_cached_ids = _get_non_cached_ids( $ids, 'sites' );
	if ( ! empty( $non_cached_ids ) ) {
		$fresh_sites = $wpdb->get_results( sprintf( "SELECT * FROM $wpdb->blogs WHERE blog_id IN (%s)", join( ',', array_map( 'intval', $non_cached_ids ) ) ) ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared

		update_site_cache( $fresh_sites, $update_meta_cache );
	}
}

/**
 * Updates sites in cache.
 *
 * @since 4.6.0
 * @since 5.1.0 Introduced the `$update_meta_cache` parameter.
 *
 * @param array $sites             Array of site objects.
 * @param bool  $update_meta_cache Whether to update site meta cache. Default true.
 */
function update_site_cache( $sites, $update_meta_cache = true ) {
	if ( ! $sites ) {
		return;
	}
	$site_ids = array();
	foreach ( $sites as $site ) {
		$site_ids[] = $site->blog_id;
		wp_cache_add( $site->blog_id, $site, 'sites' );
		wp_cache_add( $site->blog_id . 'short', $site, 'blog-details' );
	}

	if ( $update_meta_cache ) {
		update_sitemeta_cache( $site_ids );
	}
}

/**
 * Updates metadata cache for list of site IDs.
 *
 * Performs SQL query to retrieve all metadata for the sites matching `$site_ids` and stores them in the cache.
 * Subsequent calls to `get_site_meta()` will not need to query the database.
 *
 * @since 5.1.0
 *
 * @param array $site_ids List of site IDs.
 * @return array|false An array of metadata on success, false if there is nothing to update.
 */
function update_sitemeta_cache( $site_ids ) {
	// Ensure this filter is hooked in even if the function is called early.
	if ( ! has_filter( 'update_blog_metadata_cache', 'wp_check_site_meta_support_prefilter' ) ) {
		add_filter( 'update_blog_metadata_cache', 'wp_check_site_meta_support_prefilter' );
	}
	return update_meta_cache( 'blog', $site_ids );
}

/**
 * Retrieves a list of sites matching requested arguments.
 *
 * @since 4.6.0
 * @since 4.8.0 Introduced the 'lang_id', 'lang__in', and 'lang__not_in' parameters.
 *
 * @see WP_Site_Query::parse_query()
 *
 * @param string|array $args {
 *     Optional. Array or query string of site query parameters. Default empty.
 *
 *     @type array        $site__in          Array of site IDs to include. Default empty.
 *     @type array        $site__not_in      Array of site IDs to exclude. Default empty.
 *     @type bool         $count             Whether to return a site count (true) or array of site objects.
 *                                           Default false.
 *     @type array        $date_query        Date query clauses to limit sites by. See WP_Date_Query.
 *                                           Default null.
 *     @type string       $fields            Site fields to return. Accepts 'ids' (returns an array of site IDs)
 *                                           or empty (returns an array of complete site objects). Default empty.
 *     @type int          $ID                A site ID to only return that site. Default empty.
 *     @type int          $number            Maximum number of sites to retrieve. Default 100.
 *     @type int          $offset            Number of sites to offset the query. Used to build LIMIT clause.
 *                                           Default 0.
 *     @type bool         $no_found_rows     Whether to disable the `SQL_CALC_FOUND_ROWS` query. Default true.
 *     @type string|array $orderby           Site status or array of statuses. Accepts 'id', 'domain', 'path',
 *                                           'network_id', 'last_updated', 'registered', 'domain_length',
 *                                           'path_length', 'site__in' and 'network__in'. Also accepts false,
 *                                           an empty array, or 'none' to disable `ORDER BY` clause.
 *                                           Default 'id'.
 *     @type string       $order             How to order retrieved sites. Accepts 'ASC', 'DESC'. Default 'ASC'.
 *     @type int          $network_id        Limit results to those affiliated with a given network ID. If 0,
 *                                           include all networks. Default 0.
 *     @type array        $network__in       Array of network IDs to include affiliated sites for. Default empty.
 *     @type array        $network__not_in   Array of network IDs to exclude affiliated sites for. Default empty.
 *     @type string       $domain            Limit results to those affiliated with a given domain. Default empty.
 *     @type array        $domain__in        Array of domains to include affiliated sites for. Default empty.
 *     @type array        $domain__not_in    Array of domains to exclude affiliated sites for. Default empty.
 *     @type string       $path              Limit results to those affiliated with a given path. Default empty.
 *     @type array        $path__in          Array of paths to include affiliated sites for. Default empty.
 *     @type array        $path__not_in      Array of paths to exclude affiliated sites for. Default empty.
 *     @type int          $public            Limit results to public sites. Accepts '1' or '0'. Default empty.
 *     @type int          $archived          Limit results to archived sites. Accepts '1' or '0'. Default empty.
 *     @type int          $mature            Limit results to mature sites. Accepts '1' or '0'. Default empty.
 *     @type int          $spam              Limit results to spam sites. Accepts '1' or '0'. Default empty.
 *     @type int          $deleted           Limit results to deleted sites. Accepts '1' or '0'. Default empty.
 *     @type int          $lang_id           Limit results to a language ID. Default empty.
 *     @type array        $lang__in          Array of language IDs to include affiliated sites for. Default empty.
 *     @type array        $lang__not_in      Array of language IDs to exclude affiliated sites for. Default empty.
 *     @type string       $search            Search term(s) to retrieve matching sites for. Default empty.
 *     @type array        $search_columns    Array of column names to be searched. Accepts 'domain' and 'path'.
 *                                           Default empty array.
 *     @type bool         $update_site_cache Whether to prime the cache for found sites. Default true.
 * }
 * @return array|int List of WP_Site objects, a list of site IDs when 'fields' is set to 'ids',
 *                   or the number of sites when 'count' is passed as a query var.
 */
function get_sites( $args = array() ) {
	$query = new WP_Site_Query();

	return $query->query( $args );
}

/**
 * Prepares site data for insertion or update in the database.
 *
 * @since 5.1.0
 *
 * @param array        $data     Associative array of site data passed to the respective function.
 *                               See {@see wp_insert_site()} for the possibly included data.
 * @param array        $defaults Site data defaults to parse $data against.
 * @param WP_Site|null $old_site Optional. Old site object if an update, or null if an insertion.
 *                               Default null.
 * @return array|WP_Error Site data ready for a database transaction, or WP_Error in case a validation
 *                        error occurred.
 */
function wp_prepare_site_data( $data, $defaults, $old_site = null ) {

	// Maintain backward-compatibility with `$site_id` as network ID.
	if ( isset( $data['site_id'] ) ) {
		if ( ! empty( $data['site_id'] ) && empty( $data['network_id'] ) ) {
			$data['network_id'] = $data['site_id'];
		}
		unset( $data['site_id'] );
	}

	/**
	 * Filters passed site data in order to normalize it.
	 *
	 * @since 5.1.0
	 *
	 * @param array $data Associative array of site data passed to the respective function.
	 *                    See {@see wp_insert_site()} for the possibly included data.
	 */
	$data = apply_filters( 'wp_normalize_site_data', $data );

	$allowed_data_fields = array( 'domain', 'path', 'network_id', 'registered', 'last_updated', 'public', 'archived', 'mature', 'spam', 'deleted', 'lang_id' );
	$data                = array_intersect_key( wp_parse_args( $data, $defaults ), array_flip( $allowed_data_fields ) );

	$errors = new WP_Error();

	/**
	 * Fires when data should be validated for a site prior to inserting or updating in the database.
	 *
	 * Plugins should amend the `$errors` object via its `WP_Error::add()` method.
	 *
	 * @since 5.1.0
	 *
	 * @param WP_Error     $errors   Error object to add validation errors to.
	 * @param array        $data     Associative array of complete site data. See {@see wp_insert_site()}
	 *                               for the included data.
	 * @param WP_Site|null $old_site The old site object if the data belongs to a site being updated,
	 *                               or null if it is a new site being inserted.
	 */
	do_action( 'wp_validate_site_data', $errors, $data, $old_site );

	if ( ! empty( $errors->errors ) ) {
		return $errors;
	}

	// Prepare for database.
	$data['site_id'] = $data['network_id'];
	unset( $data['network_id'] );

	return $data;
}

/**
 * Normalizes data for a site prior to inserting or updating in the database.
 *
 * @since 5.1.0
 *
 * @param array $data Associative array of site data passed to the respective function.
 *                    See {@see wp_insert_site()} for the possibly included data.
 * @return array Normalized site data.
 */
function wp_normalize_site_data( $data ) {
	// Sanitize domain if passed.
	if ( array_key_exists( 'domain', $data ) ) {
		$data['domain'] = trim( $data['domain'] );
		$data['domain'] = preg_replace( '/\s+/', '', sanitize_user( $data['domain'], true ) );
		if ( is_subdomain_install() ) {
			$data['domain'] = str_replace( '@', '', $data['domain'] );
		}
	}

	// Sanitize path if passed.
	if ( array_key_exists( 'path', $data ) ) {
		$data['path'] = trailingslashit( '/' . trim( $data['path'], '/' ) );
	}

	// Sanitize network ID if passed.
	if ( array_key_exists( 'network_id', $data ) ) {
		$data['network_id'] = (int) $data['network_id'];
	}

	// Sanitize status fields if passed.
	$status_fields = array( 'public', 'archived', 'mature', 'spam', 'deleted' );
	foreach ( $status_fields as $status_field ) {
		if ( array_key_exists( $status_field, $data ) ) {
			$data[ $status_field ] = (int) $data[ $status_field ];
		}
	}

	// Strip date fields if empty.
	$date_fields = array( 'registered', 'last_updated' );
	foreach ( $date_fields as $date_field ) {
		if ( ! array_key_exists( $date_field, $data ) ) {
			continue;
		}

		if ( empty( $data[ $date_field ] ) || '0000-00-00 00:00:00' === $data[ $date_field ] ) {
			unset( $data[ $date_field ] );
		}
	}

	return $data;
}

/**
 * Validates data for a site prior to inserting or updating in the database.
 *
 * @since 5.1.0
 *
 * @param WP_Error     $errors   Error object, passed by reference. Will contain validation errors if
 *                               any occurred.
 * @param array        $data     Associative array of complete site data. See {@see wp_insert_site()}
 *                               for the included data.
 * @param WP_Site|null $old_site The old site object if the data belongs to a site being updated,
 *                               or null if it is a new site being inserted.
 */
function wp_validate_site_data( $errors, $data, $old_site = null ) {
	// A domain must always be present.
	if ( empty( $data['domain'] ) ) {
		$errors->add( 'site_empty_domain', __( 'Site domain must not be empty.' ) );
	}

	// A path must always be present.
	if ( empty( $data['path'] ) ) {
		$errors->add( 'site_empty_path', __( 'Site path must not be empty.' ) );
	}

	// A network ID must always be present.
	if ( empty( $data['network_id'] ) ) {
		$errors->add( 'site_empty_network_id', __( 'Site network ID must be provided.' ) );
	}

	// Both registration and last updated dates must always be present and valid.
	$date_fields = array( 'registered', 'last_updated' );
	foreach ( $date_fields as $date_field ) {
		if ( empty( $data[ $date_field ] ) ) {
			$errors->add( 'site_empty_' . $date_field, __( 'Both registration and last updated dates must be provided.' ) );
			break;
		}

		// Allow '0000-00-00 00:00:00', although it be stripped out at this point.
		if ( '0000-00-00 00:00:00' !== $data[ $date_field ] ) {
			$month      = substr( $data[ $date_field ], 5, 2 );
			$day        = substr( $data[ $date_field ], 8, 2 );
			$year       = substr( $data[ $date_field ], 0, 4 );
			$valid_date = wp_checkdate( $month, $day, $year, $data[ $date_field ] );
			if ( ! $valid_date ) {
				$errors->add( 'site_invalid_' . $date_field, __( 'Both registration and last updated dates must be valid dates.' ) );
				break;
			}
		}
	}

	if ( ! empty( $errors->errors ) ) {
		return;
	}

	// If a new site, or domain/path/network ID have changed, ensure uniqueness.
	if ( ! $old_site
		|| $data['domain'] !== $old_site->domain
		|| $data['path'] !== $old_site->path
		|| $data['network_id'] !== $old_site->network_id
	) {
		if ( domain_exists( $data['domain'], $data['path'], $data['network_id'] ) ) {
			$errors->add( 'site_taken', __( 'Sorry, that site already exists!' ) );
		}
	}
}

/**
 * Runs the initialization routine for a given site.
 *
 * This process includes creating the site's database tables and
 * populating them with defaults.
 *
 * @since 5.1.0
 *
 * @global wpdb     $wpdb     WordPress database abstraction object.
 * @global WP_Roles $wp_roles WordPress role management object.
 *
 * @param int|WP_Site $site_id Site ID or object.
 * @param array       $args    {
 *     Optional. Arguments to modify the initialization behavior.
 *
 *     @type int    $user_id Required. User ID for the site administrator.
 *     @type string $title   Site title. Default is 'Site %d' where %d is the
 *                           site ID.
 *     @type array  $options Custom option $key => $value pairs to use. Default
 *                           empty array.
 *     @type array  $meta    Custom site metadata $key => $value pairs to use.
 *                           Default empty array.
 * }
 * @return bool|WP_Error True on success, or error object on failure.
 */
function wp_initialize_site( $site_id, array $args = array() ) {
	global $wpdb, $wp_roles;

	if ( empty( $site_id ) ) {
		return new WP_Error( 'site_empty_id', __( 'Site ID must not be empty.' ) );
	}

	$site = get_site( $site_id );
	if ( ! $site ) {
		return new WP_Error( 'site_invalid_id', __( 'Site with the ID does not exist.' ) );
	}

	if ( wp_is_site_initialized( $site ) ) {
		return new WP_Error( 'site_already_initialized', __( 'The site appears to be already initialized.' ) );
	}

	$network = get_network( $site->network_id );
	if ( ! $network ) {
		$network = get_network();
	}

	$args = wp_parse_args(
		$args,
		array(
			'user_id' => 0,
			/* translators: %d: Site ID. */
			'title'   => sprintf( __( 'Site %d' ), $site->id ),
			'options' => array(),
			'meta'    => array(),
		)
	);

	/**
	 * Filters the arguments for initializing a site.
	 *
	 * @since 5.1.0
	 *
	 * @param array      $args    Arguments to modify the initialization behavior.
	 * @param WP_Site    $site    Site that is being initialized.
	 * @param WP_Network $network Network that the site belongs to.
	 */
	$args = apply_filters( 'wp_initialize_site_args', $args, $site, $network );

	$orig_installing = wp_installing();
	if ( ! $orig_installing ) {
		wp_installing( true );
	}

	$switch = false;
	if ( get_current_blog_id() !== $site->id ) {
		$switch = true;
		switch_to_blog( $site->id );
	}

	require_once ABSPATH . 'wp-admin/includes/upgrade.php';

	// Set up the database tables.
	make_db_current_silent( 'blog' );

	$home_scheme    = 'http';
	$siteurl_scheme = 'http';
	if ( ! is_subdomain_install() ) {
		if ( 'https' === parse_url( get_home_url( $network->site_id ), PHP_URL_SCHEME ) ) {
			$home_scheme = 'https';
		}
		if ( 'https' === parse_url( get_network_option( $network->id, 'siteurl' ), PHP_URL_SCHEME ) ) {
			$siteurl_scheme = 'https';
		}
	}

	// Populate the site's options.
	populate_options(
		array_merge(
			array(
				'home'        => untrailingslashit( $home_scheme . '://' . $site->domain . $site->path ),
				'siteurl'     => untrailingslashit( $siteurl_scheme . '://' . $site->domain . $site->path ),
				'blogname'    => wp_unslash( $args['title'] ),
				'admin_email' => '',
				'upload_path' => get_network_option( $network->id, 'ms_files_rewriting' ) ? UPLOADBLOGSDIR . "/{$site->id}/files" : get_blog_option( $network->site_id, 'upload_path' ),
				'blog_public' => (int) $site->public,
				'WPLANG'      => get_network_option( $network->id, 'WPLANG' ),
			),
			$args['options']
		)
	);

	// Clean blog cache after populating options.
	clean_blog_cache( $site );

	// Populate the site's roles.
	populate_roles();
	$wp_roles = new WP_Roles();

	// Populate metadata for the site.
	populate_site_meta( $site->id, $args['meta'] );

	// Remove all permissions that may exist for the site.
	$table_prefix = $wpdb->get_blog_prefix();
	delete_metadata( 'user', 0, $table_prefix . 'user_level', null, true );   // Delete all.
	delete_metadata( 'user', 0, $table_prefix . 'capabilities', null, true ); // Delete all.

	// Install default site content.
	wp_install_defaults( $args['user_id'] );

	// Set the site administrator.
	add_user_to_blog( $site->id, $args['user_id'], 'administrator' );
	if ( ! user_can( $args['user_id'], 'manage_network' ) && ! get_user_meta( $args['user_id'], 'primary_blog', true ) ) {
		update_user_meta( $args['user_id'], 'primary_blog', $site->id );
	}

	if ( $switch ) {
		restore_current_blog();
	}

	wp_installing( $orig_installing );

	return true;
}

/**
 * Runs the uninitialization routine for a given site.
 *
 * This process includes dropping the site's database tables and deleting its uploads directory.
 *
 * @since 5.1.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int|WP_Site $site_id Site ID or object.
 * @return bool|WP_Error True on success, or error object on failure.
 */
function wp_uninitialize_site( $site_id ) {
	global $wpdb;

	if ( empty( $site_id ) ) {
		return new WP_Error( 'site_empty_id', __( 'Site ID must not be empty.' ) );
	}

	$site = get_site( $site_id );
	if ( ! $site ) {
		return new WP_Error( 'site_invalid_id', __( 'Site with the ID does not exist.' ) );
	}

	if ( ! wp_is_site_initialized( $site ) ) {
		return new WP_Error( 'site_already_uninitialized', __( 'The site appears to be already uninitialized.' ) );
	}

	$users = get_users(
		array(
			'blog_id' => $site->id,
			'fields'  => 'ids',
		)
	);

	// Remove users from the site.
	if ( ! empty( $users ) ) {
		foreach ( $users as $user_id ) {
			remove_user_from_blog( $user_id, $site->id );
		}
	}

	$switch = false;
	if ( get_current_blog_id() !== $site->id ) {
		$switch = true;
		switch_to_blog( $site->id );
	}

	$uploads = wp_get_upload_dir();

	$tables = $wpdb->tables( 'blog' );

	/**
	 * Filters the tables to drop when the site is deleted.
	 *
	 * @since MU (3.0.0)
	 *
	 * @param string[] $tables  Array of names of the site tables to be dropped.
	 * @param int      $site_id The ID of the site to drop tables for.
	 */
	$drop_tables = apply_filters( 'wpmu_drop_tables', $tables, $site->id );

	foreach ( (array) $drop_tables as $table ) {
		$wpdb->query( "DROP TABLE IF EXISTS `$table`" ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
	}

	/**
	 * Filters the upload base directory to delete when the site is deleted.
	 *
	 * @since MU (3.0.0)
	 *
	 * @param string $uploads['basedir'] Uploads path without subdirectory. @see wp_upload_dir()
	 * @param int    $site_id            The site ID.
	 */
	$dir     = apply_filters( 'wpmu_delete_blog_upload_dir', $uploads['basedir'], $site->id );
	$dir     = rtrim( $dir, DIRECTORY_SEPARATOR );
	$top_dir = $dir;
	$stack   = array( $dir );
	$index   = 0;

	while ( $index < count( $stack ) ) {
		// Get indexed directory from stack.
		$dir = $stack[ $index ];

		// phpcs:disable WordPress.PHP.NoSilencedErrors.Discouraged
		$dh = @opendir( $dir );
		if ( $dh ) {
			$file = @readdir( $dh );
			while ( false !== $file ) {
				if ( '.' === $file || '..' === $file ) {
					$file = @readdir( $dh );
					continue;
				}

				if ( @is_dir( $dir . DIRECTORY_SEPARATOR . $file ) ) {
					$stack[] = $dir . DIRECTORY_SEPARATOR . $file;
				} elseif ( @is_file( $dir . DIRECTORY_SEPARATOR . $file ) ) {
					@unlink( $dir . DIRECTORY_SEPARATOR . $file );
				}

				$file = @readdir( $dh );
			}
			@closedir( $dh );
		}
		$index++;
	}

	$stack = array_reverse( $stack ); // Last added directories are deepest.
	foreach ( (array) $stack as $dir ) {
		if ( $dir != $top_dir ) {
			@rmdir( $dir );
		}
	}

	// phpcs:enable WordPress.PHP.NoSilencedErrors.Discouraged
	if ( $switch ) {
		restore_current_blog();
	}

	return true;
}

/**
 * Checks whether a site is initialized.
 *
 * A site is considered initialized when its database tables are present.
 *
 * @since 5.1.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int|WP_Site $site_id Site ID or object.
 * @return bool True if the site is initialized, false otherwise.
 */
function wp_is_site_initialized( $site_id ) {
	global $wpdb;

	if ( is_object( $site_id ) ) {
		$site_id = $site_id->blog_id;
	}
	$site_id = (int) $site_id;

	/**
	 * Filters the check for whether a site is initialized before the database is accessed.
	 *
	 * Returning a non-null value will effectively short-circuit the function, returning
	 * that value instead.
	 *
	 * @since 5.1.0
	 *
	 * @param bool|null $pre     The value to return instead. Default null
	 *                           to continue with the check.
	 * @param int       $site_id The site ID that is being checked.
	 */
	$pre = apply_filters( 'pre_wp_is_site_initialized', null, $site_id );
	if ( null !== $pre ) {
		return (bool) $pre;
	}

	$switch = false;
	if ( get_current_blog_id() !== $site_id ) {
		$switch = true;
		remove_action( 'switch_blog', 'wp_switch_roles_and_user', 1 );
		switch_to_blog( $site_id );
	}

	$suppress = $wpdb->suppress_errors();
	$result   = (bool) $wpdb->get_results( "DESCRIBE {$wpdb->posts}" );
	$wpdb->suppress_errors( $suppress );

	if ( $switch ) {
		restore_current_blog();
		add_action( 'switch_blog', 'wp_switch_roles_and_user', 1, 2 );
	}

	return $result;
}

/**
 * Clean the blog cache
 *
 * @since 3.5.0
 *
 * @global bool $_wp_suspend_cache_invalidation
 *
 * @param WP_Site|int $blog The site object or ID to be cleared from cache.
 */
function clean_blog_cache( $blog ) {
	global $_wp_suspend_cache_invalidation;

	if ( ! empty( $_wp_suspend_cache_invalidation ) ) {
		return;
	}

	if ( empty( $blog ) ) {
		return;
	}

	$blog_id = $blog;
	$blog    = get_site( $blog_id );
	if ( ! $blog ) {
		if ( ! is_numeric( $blog_id ) ) {
			return;
		}

		// Make sure a WP_Site object exists even when the site has been deleted.
		$blog = new WP_Site(
			(object) array(
				'blog_id' => $blog_id,
				'domain'  => null,
				'path'    => null,
			)
		);
	}

	$blog_id         = $blog->blog_id;
	$domain_path_key = md5( $blog->domain . $blog->path );

	wp_cache_delete( $blog_id, 'sites' );
	wp_cache_delete( $blog_id, 'site-details' );
	wp_cache_delete( $blog_id, 'blog-details' );
	wp_cache_delete( $blog_id . 'short', 'blog-details' );
	wp_cache_delete( $domain_path_key, 'blog-lookup' );
	wp_cache_delete( $domain_path_key, 'blog-id-cache' );
	wp_cache_delete( $blog_id, 'blog_meta' );

	/**
	 * Fires immediately after a site has been removed from the object cache.
	 *
	 * @since 4.6.0
	 *
	 * @param int     $id              Blog ID.
	 * @param WP_Site $blog            Site object.
	 * @param string  $domain_path_key md5 hash of domain and path.
	 */
	do_action( 'clean_site_cache', $blog_id, $blog, $domain_path_key );

	wp_cache_set( 'last_changed', microtime(), 'sites' );

	/**
	 * Fires after the blog details cache is cleared.
	 *
	 * @since 3.4.0
	 * @deprecated 4.9.0 Use {@see 'clean_site_cache'} instead.
	 *
	 * @param int $blog_id Blog ID.
	 */
	do_action_deprecated( 'refresh_blog_details', array( $blog_id ), '4.9.0', 'clean_site_cache' );
}

/**
 * Adds metadata to a site.
 *
 * @since 5.1.0
 *
 * @param int    $site_id    Site ID.
 * @param string $meta_key   Metadata name.
 * @param mixed  $meta_value Metadata value. Must be serializable if non-scalar.
 * @param bool   $unique     Optional. Whether the same key should not be added.
 *                           Default false.
 * @return int|false Meta ID on success, false on failure.
 */
function add_site_meta( $site_id, $meta_key, $meta_value, $unique = false ) {
	return add_metadata( 'blog', $site_id, $meta_key, $meta_value, $unique );
}

/**
 * Removes metadata matching criteria from a site.
 *
 * You can match based on the key, or key and value. Removing based on key and
 * value, will keep from removing duplicate metadata with the same key. It also
 * allows removing all metadata matching key, if needed.
 *
 * @since 5.1.0
 *
 * @param int    $site_id    Site ID.
 * @param string $meta_key   Metadata name.
 * @param mixed  $meta_value Optional. Metadata value. If provided,
 *                           rows will only be removed that match the value.
 *                           Must be serializable if non-scalar. Default empty.
 * @return bool True on success, false on failure.
 */
function delete_site_meta( $site_id, $meta_key, $meta_value = '' ) {
	return delete_metadata( 'blog', $site_id, $meta_key, $meta_value );
}

/**
 * Retrieves metadata for a site.
 *
 * @since 5.1.0
 *
 * @param int    $site_id Site ID.
 * @param string $key     Optional. The meta key to retrieve. By default,
 *                        returns data for all keys. Default empty.
 * @param bool   $single  Optional. Whether to return a single value.
 *                        This parameter has no effect if $key is not specified.
 *                        Default false.
 * @return mixed An array if $single is false. The value of meta data field
 *               if $single is true. False for an invalid $site_id.
 */
function get_site_meta( $site_id, $key = '', $single = false ) {
	return get_metadata( 'blog', $site_id, $key, $single );
}

/**
 * Updates metadata for a site.
 *
 * Use the $prev_value parameter to differentiate between meta fields with the
 * same key and site ID.
 *
 * If the meta field for the site does not exist, it will be added.
 *
 * @since 5.1.0
 *
 * @param int    $site_id    Site ID.
 * @param string $meta_key   Metadata key.
 * @param mixed  $meta_value Metadata value. Must be serializable if non-scalar.
 * @param mixed  $prev_value Optional. Previous value to check before updating.
 *                           If specified, only update existing metadata entries with
 *                           this value. Otherwise, update all entries. Default empty.
 * @return int|bool Meta ID if the key didn't exist, true on successful update,
 *                  false on failure or if the value passed to the function
 *                  is the same as the one that is already in the database.
 */
function update_site_meta( $site_id, $meta_key, $meta_value, $prev_value = '' ) {
	return update_metadata( 'blog', $site_id, $meta_key, $meta_value, $prev_value );
}

/**
 * Deletes everything from site meta matching meta key.
 *
 * @since 5.1.0
 *
 * @param string $meta_key Metadata key to search for when deleting.
 * @return bool Whether the site meta key was deleted from the database.
 */
function delete_site_meta_by_key( $meta_key ) {
	return delete_metadata( 'blog', null, $meta_key, '', true );
}

/**
 * Updates the count of sites for a network based on a changed site.
 *
 * @since 5.1.0
 *
 * @param WP_Site      $new_site The site object that has been inserted, updated or deleted.
 * @param WP_Site|null $old_site Optional. If $new_site has been updated, this must be the previous
 *                               state of that site. Default null.
 */
function wp_maybe_update_network_site_counts_on_update( $new_site, $old_site = null ) {
	if ( null === $old_site ) {
		wp_maybe_update_network_site_counts( $new_site->network_id );
		return;
	}

	if ( $new_site->network_id != $old_site->network_id ) {
		wp_maybe_update_network_site_counts( $new_site->network_id );
		wp_maybe_update_network_site_counts( $old_site->network_id );
	}
}

/**
 * Triggers actions on site status updates.
 *
 * @since 5.1.0
 *
 * @param WP_Site      $new_site The site object after the update.
 * @param WP_Site|null $old_site Optional. If $new_site has been updated, this must be the previous
 *                               state of that site. Default null.
 */
function wp_maybe_transition_site_statuses_on_update( $new_site, $old_site = null ) {
	$site_id = $new_site->id;

	// Use the default values for a site if no previous state is given.
	if ( ! $old_site ) {
		$old_site = new WP_Site( new stdClass() );
	}

	if ( $new_site->spam != $old_site->spam ) {
		if ( 1 == $new_site->spam ) {

			/**
			 * Fires when the 'spam' status is added to a site.
			 *
			 * @since MU (3.0.0)
			 *
			 * @param int $site_id Site ID.
			 */
			do_action( 'make_spam_blog', $site_id );
		} else {

			/**
			 * Fires when the 'spam' status is removed from a site.
			 *
			 * @since MU (3.0.0)
			 *
			 * @param int $site_id Site ID.
			 */
			do_action( 'make_ham_blog', $site_id );
		}
	}

	if ( $new_site->mature != $old_site->mature ) {
		if ( 1 == $new_site->mature ) {

			/**
			 * Fires when the 'mature' status is added to a site.
			 *
			 * @since 3.1.0
			 *
			 * @param int $site_id Site ID.
			 */
			do_action( 'mature_blog', $site_id );
		} else {

			/**
			 * Fires when the 'mature' status is removed from a site.
			 *
			 * @since 3.1.0
			 *
			 * @param int $site_id Site ID.
			 */
			do_action( 'unmature_blog', $site_id );
		}
	}

	if ( $new_site->archived != $old_site->archived ) {
		if ( 1 == $new_site->archived ) {

			/**
			 * Fires when the 'archived' status is added to a site.
			 *
			 * @since MU (3.0.0)
			 *
			 * @param int $site_id Site ID.
			 */
			do_action( 'archive_blog', $site_id );
		} else {

			/**
			 * Fires when the 'archived' status is removed from a site.
			 *
			 * @since MU (3.0.0)
			 *
			 * @param int $site_id Site ID.
			 */
			do_action( 'unarchive_blog', $site_id );
		}
	}

	if ( $new_site->deleted != $old_site->deleted ) {
		if ( 1 == $new_site->deleted ) {

			/**
			 * Fires when the 'deleted' status is added to a site.
			 *
			 * @since 3.5.0
			 *
			 * @param int $site_id Site ID.
			 */
			do_action( 'make_delete_blog', $site_id );
		} else {

			/**
			 * Fires when the 'deleted' status is removed from a site.
			 *
			 * @since 3.5.0
			 *
			 * @param int $site_id Site ID.
			 */
			do_action( 'make_undelete_blog', $site_id );
		}
	}

	if ( $new_site->public != $old_site->public ) {

		/**
		 * Fires after the current blog's 'public' setting is updated.
		 *
		 * @since MU (3.0.0)
		 *
		 * @param int    $site_id Site ID.
		 * @param string $value   The value of the site status.
		 */
		do_action( 'update_blog_public', $site_id, $new_site->public );
	}
}

/**
 * Cleans the necessary caches after specific site data has been updated.
 *
 * @since 5.1.0
 *
 * @param WP_Site $new_site The site object after the update.
 * @param WP_Site $old_site The site obejct prior to the update.
 */
function wp_maybe_clean_new_site_cache_on_update( $new_site, $old_site ) {
	if ( $old_site->domain !== $new_site->domain || $old_site->path !== $new_site->path ) {
		clean_blog_cache( $new_site );
	}
}

/**
 * Updates the `blog_public` option for a given site ID.
 *
 * @since 5.1.0
 *
 * @param int    $site_id Site ID.
 * @param string $public  The value of the site status.
 */
function wp_update_blog_public_option_on_site_update( $site_id, $public ) {

	// Bail if the site's database tables do not exist (yet).
	if ( ! wp_is_site_initialized( $site_id ) ) {
		return;
	}

	update_blog_option( $site_id, 'blog_public', $public );
}

/**
 * Sets the last changed time for the 'sites' cache group.
 *
 * @since 5.1.0
 */
function wp_cache_set_sites_last_changed() {
	wp_cache_set( 'last_changed', microtime(), 'sites' );
}

/**
 * Aborts calls to site meta if it is not supported.
 *
 * @since 5.1.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param mixed $check Skip-value for whether to proceed site meta function execution.
 * @return mixed Original value of $check, or false if site meta is not supported.
 */
function wp_check_site_meta_support_prefilter( $check ) {
	if ( ! is_site_meta_supported() ) {
		/* translators: %s: Database table name. */
		_doing_it_wrong( __FUNCTION__, sprintf( __( 'The %s table is not installed. Please run the network database upgrade.' ), $GLOBALS['wpdb']->blogmeta ), '5.1.0' );
		return false;
	}

	return $check;
}


<?php
/**
 * Nav Menu API: Template functions
 *
 * @package WordPress
 * @subpackage Nav_Menus
 * @since 3.0.0
 */

/** Walker_Nav_Menu class */
require_once ABSPATH . WPINC . '/class-walker-nav-menu.php';

/**
 * Displays a navigation menu.
 *
 * @since 3.0.0
 * @since 4.7.0 Added the `item_spacing` argument.
 * @since 5.5.0 Added the `container_aria_label` argument.
 *
 * @param array $args {
 *     Optional. Array of nav menu arguments.
 *
 *     @type int|string|WP_Term $menu                 Desired menu. Accepts a menu ID, slug, name, or object.
 *                                                    Default empty.
 *     @type string             $menu_class           CSS class to use for the ul element which forms the menu.
 *                                                    Default 'menu'.
 *     @type string             $menu_id              The ID that is applied to the ul element which forms the menu.
 *                                                    Default is the menu slug, incremented.
 *     @type string             $container            Whether to wrap the ul, and what to wrap it with.
 *                                                    Default 'div'.
 *     @type string             $container_class      Class that is applied to the container.
 *                                                    Default 'menu-{menu slug}-container'.
 *     @type string             $container_id         The ID that is applied to the container. Default empty.
 *     @type string             $container_aria_label The aria-label attribute that is applied to the container
 *                                                    when it's a nav element. Default empty.
 *     @type callable|bool      $fallback_cb          If the menu doesn't exist, a callback function will fire.
 *                                                    Default is 'wp_page_menu'. Set to false for no fallback.
 *     @type string             $before               Text before the link markup. Default empty.
 *     @type string             $after                Text after the link markup. Default empty.
 *     @type string             $link_before          Text before the link text. Default empty.
 *     @type string             $link_after           Text after the link text. Default empty.
 *     @type bool               $echo                 Whether to echo the menu or return it. Default true.
 *     @type int                $depth                How many levels of the hierarchy are to be included.
 *                                                    0 means all. Default 0.
 *                                                    Default 0.
 *     @type object             $walker               Instance of a custom walker class. Default empty.
 *     @type string             $theme_location       Theme location to be used. Must be registered with
 *                                                    register_nav_menu() in order to be selectable by the user.
 *     @type string             $items_wrap           How the list items should be wrapped. Uses printf() format with
 *                                                    numbered placeholders. Default is a ul with an id and class.
 *     @type string             $item_spacing         Whether to preserve whitespace within the menu's HTML.
 *                                                    Accepts 'preserve' or 'discard'. Default 'preserve'.
 * }
 * @return void|string|false Void if 'echo' argument is true, menu output if 'echo' is false.
 *                           False if there are no items or no menu was found.
 */
function wp_nav_menu( $args = array() ) {
	static $menu_id_slugs = array();

	$defaults = array(
		'menu'                 => '',
		'container'            => 'div',
		'container_class'      => '',
		'container_id'         => '',
		'container_aria_label' => '',
		'menu_class'           => 'menu',
		'menu_id'              => '',
		'echo'                 => true,
		'fallback_cb'          => 'wp_page_menu',
		'before'               => '',
		'after'                => '',
		'link_before'          => '',
		'link_after'           => '',
		'items_wrap'           => '
%3$s
',
		'item_spacing'         => 'preserve',
		'depth'                => 0,
		'walker'               => '',
		'theme_location'       => '',
	);

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

	if ( ! in_array( $args['item_spacing'], array( 'preserve', 'discard' ), true ) ) {
		// Invalid value, fall back to default.
		$args['item_spacing'] = $defaults['item_spacing'];
	}

	/**
	 * Filters the arguments used to display a navigation menu.
	 *
	 * @since 3.0.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param array $args Array of wp_nav_menu() arguments.
	 */
	$args = apply_filters( 'wp_nav_menu_args', $args );
	$args = (object) $args;

	/**
	 * Filters whether to short-circuit the wp_nav_menu() output.
	 *
	 * Returning a non-null value from the filter will short-circuit wp_nav_menu(),
	 * echoing that value if $args->echo is true, returning that value otherwise.
	 *
	 * @since 3.9.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param string|null $output Nav menu output to short-circuit with. Default null.
	 * @param stdClass    $args   An object containing wp_nav_menu() arguments.
	 */
	$nav_menu = apply_filters( 'pre_wp_nav_menu', null, $args );

	if ( null !== $nav_menu ) {
		if ( $args->echo ) {
			echo $nav_menu;
			return;
		}

		return $nav_menu;
	}

	// Get the nav menu based on the requested menu.
	$menu = wp_get_nav_menu_object( $args->menu );

	// Get the nav menu based on the theme_location.
	$locations = get_nav_menu_locations();
	if ( ! $menu && $args->theme_location && $locations && isset( $locations[ $args->theme_location ] ) ) {
		$menu = wp_get_nav_menu_object( $locations[ $args->theme_location ] );
	}

	// Get the first menu that has items if we still can't find a menu.
	if ( ! $menu && ! $args->theme_location ) {
		$menus = wp_get_nav_menus();
		foreach ( $menus as $menu_maybe ) {
			$menu_items = wp_get_nav_menu_items( $menu_maybe->term_id, array( 'update_post_term_cache' => false ) );
			if ( $menu_items ) {
				$menu = $menu_maybe;
				break;
			}
		}
	}

	if ( empty( $args->menu ) ) {
		$args->menu = $menu;
	}

	// If the menu exists, get its items.
	if ( $menu && ! is_wp_error( $menu ) && ! isset( $menu_items ) ) {
		$menu_items = wp_get_nav_menu_items( $menu->term_id, array( 'update_post_term_cache' => false ) );
	}

	/*
	 * If no menu was found:
	 *  - Fall back (if one was specified), or bail.
	 *
	 * If no menu items were found:
	 *  - Fall back, but only if no theme location was specified.
	 *  - Otherwise, bail.
	 */
	if ( ( ! $menu || is_wp_error( $menu ) || ( isset( $menu_items ) && empty( $menu_items ) && ! $args->theme_location ) )
		&& isset( $args->fallback_cb ) && $args->fallback_cb && is_callable( $args->fallback_cb ) ) {
			return call_user_func( $args->fallback_cb, (array) $args );
	}

	if ( ! $menu || is_wp_error( $menu ) ) {
		return false;
	}

	$nav_menu = '';
	$items    = '';

	$show_container = false;
	if ( $args->container ) {
		/**
		 * Filters the list of HTML tags that are valid for use as menu containers.
		 *
		 * @since 3.0.0
		 *
		 * @param string[] $tags The acceptable HTML tags for use as menu containers.
		 *                       Default is array containing 'div' and 'nav'.
		 */
		$allowed_tags = apply_filters( 'wp_nav_menu_container_allowedtags', array( 'div', 'nav' ) );

		if ( is_string( $args->container ) && in_array( $args->container, $allowed_tags, true ) ) {
			$show_container = true;
			$class          = $args->container_class ? ' class="' . esc_attr( $args->container_class ) . '"' : ' class="menu-' . $menu->slug . '-container"';
			$id             = $args->container_id ? ' id="' . esc_attr( $args->container_id ) . '"' : '';
			$aria_label     = ( 'nav' === $args->container && $args->container_aria_label ) ? ' aria-label="' . esc_attr( $args->container_aria_label ) . '"' : '';
			$nav_menu      .= '<' . $args->container . $id . $class . $aria_label . '>';
		}
	}

	// Set up the $menu_item variables.
	_wp_menu_item_classes_by_context( $menu_items );

	$sorted_menu_items        = array();
	$menu_items_with_children = array();
	foreach ( (array) $menu_items as $menu_item ) {
		$sorted_menu_items[ $menu_item->menu_order ] = $menu_item;
		if ( $menu_item->menu_item_parent ) {
			$menu_items_with_children[ $menu_item->menu_item_parent ] = true;
		}
	}

	// Add the menu-item-has-children class where applicable.
	if ( $menu_items_with_children ) {
		foreach ( $sorted_menu_items as &$menu_item ) {
			if ( isset( $menu_items_with_children[ $menu_item->ID ] ) ) {
				$menu_item->classes[] = 'menu-item-has-children';
			}
		}
	}

	unset( $menu_items, $menu_item );

	/**
	 * Filters the sorted list of menu item objects before generating the menu's HTML.
	 *
	 * @since 3.1.0
	 *
	 * @param array    $sorted_menu_items The menu items, sorted by each menu item's menu order.
	 * @param stdClass $args              An object containing wp_nav_menu() arguments.
	 */
	$sorted_menu_items = apply_filters( 'wp_nav_menu_objects', $sorted_menu_items, $args );

	$items .= walk_nav_menu_tree( $sorted_menu_items, $args->depth, $args );
	unset( $sorted_menu_items );

	// Attributes.
	if ( ! empty( $args->menu_id ) ) {
		$wrap_id = $args->menu_id;
	} else {
		$wrap_id = 'menu-' . $menu->slug;

		while ( in_array( $wrap_id, $menu_id_slugs, true ) ) {
			if ( preg_match( '#-(\d+)$#', $wrap_id, $matches ) ) {
				$wrap_id = preg_replace( '#-(\d+)$#', '-' . ++$matches[1], $wrap_id );
			} else {
				$wrap_id = $wrap_id . '-1';
			}
		}
	}
	$menu_id_slugs[] = $wrap_id;

	$wrap_class = $args->menu_class ? $args->menu_class : '';

	/**
	 * Filters the HTML list content for navigation menus.
	 *
	 * @since 3.0.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param string   $items The HTML list content for the menu items.
	 * @param stdClass $args  An object containing wp_nav_menu() arguments.
	 */
	$items = apply_filters( 'wp_nav_menu_items', $items, $args );
	/**
	 * Filters the HTML list content for a specific navigation menu.
	 *
	 * @since 3.0.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param string   $items The HTML list content for the menu items.
	 * @param stdClass $args  An object containing wp_nav_menu() arguments.
	 */
	$items = apply_filters( "wp_nav_menu_{$menu->slug}_items", $items, $args );

	// Don't print any markup if there are no items at this point.
	if ( empty( $items ) ) {
		return false;
	}

	$nav_menu .= sprintf( $args->items_wrap, esc_attr( $wrap_id ), esc_attr( $wrap_class ), $items );
	unset( $items );

	if ( $show_container ) {
		$nav_menu .= '</' . $args->container . '>';
	}

	/**
	 * Filters the HTML content for navigation menus.
	 *
	 * @since 3.0.0
	 *
	 * @see wp_nav_menu()
	 *
	 * @param string   $nav_menu The HTML content for the navigation menu.
	 * @param stdClass $args     An object containing wp_nav_menu() arguments.
	 */
	$nav_menu = apply_filters( 'wp_nav_menu', $nav_menu, $args );

	if ( $args->echo ) {
		echo $nav_menu;
	} else {
		return $nav_menu;
	}
}

/**
 * Adds the class property classes for the current context, if applicable.
 *
 * @access private
 * @since 3.0.0
 *
 * @global WP_Query   $wp_query   WordPress Query object.
 * @global WP_Rewrite $wp_rewrite WordPress rewrite component.
 *
 * @param array $menu_items The current menu item objects to which to add the class property information.
 */
function _wp_menu_item_classes_by_context( &$menu_items ) {
	global $wp_query, $wp_rewrite;

	$queried_object    = $wp_query->get_queried_object();
	$queried_object_id = (int) $wp_query->queried_object_id;

	$active_object               = '';
	$active_ancestor_item_ids    = array();
	$active_parent_item_ids      = array();
	$active_parent_object_ids    = array();
	$possible_taxonomy_ancestors = array();
	$possible_object_parents     = array();
	$home_page_id                = (int) get_option( 'page_for_posts' );

	if ( $wp_query->is_singular && ! empty( $queried_object->post_type ) && ! is_post_type_hierarchical( $queried_object->post_type ) ) {
		foreach ( (array) get_object_taxonomies( $queried_object->post_type ) as $taxonomy ) {
			if ( is_taxonomy_hierarchical( $taxonomy ) ) {
				$term_hierarchy = _get_term_hierarchy( $taxonomy );
				$terms          = wp_get_object_terms( $queried_object_id, $taxonomy, array( 'fields' => 'ids' ) );
				if ( is_array( $terms ) ) {
					$possible_object_parents = array_merge( $possible_object_parents, $terms );
					$term_to_ancestor        = array();
					foreach ( (array) $term_hierarchy as $anc => $descs ) {
						foreach ( (array) $descs as $desc ) {
							$term_to_ancestor[ $desc ] = $anc;
						}
					}

					foreach ( $terms as $desc ) {
						do {
							$possible_taxonomy_ancestors[ $taxonomy ][] = $desc;
							if ( isset( $term_to_ancestor[ $desc ] ) ) {
								$_desc = $term_to_ancestor[ $desc ];
								unset( $term_to_ancestor[ $desc ] );
								$desc = $_desc;
							} else {
								$desc = 0;
							}
						} while ( ! empty( $desc ) );
					}
				}
			}
		}
	} elseif ( ! empty( $queried_object->taxonomy ) && is_taxonomy_hierarchical( $queried_object->taxonomy ) ) {
		$term_hierarchy   = _get_term_hierarchy( $queried_object->taxonomy );
		$term_to_ancestor = array();
		foreach ( (array) $term_hierarchy as $anc => $descs ) {
			foreach ( (array) $descs as $desc ) {
				$term_to_ancestor[ $desc ] = $anc;
			}
		}
		$desc = $queried_object->term_id;
		do {
			$possible_taxonomy_ancestors[ $queried_object->taxonomy ][] = $desc;
			if ( isset( $term_to_ancestor[ $desc ] ) ) {
				$_desc = $term_to_ancestor[ $desc ];
				unset( $term_to_ancestor[ $desc ] );
				$desc = $_desc;
			} else {
				$desc = 0;
			}
		} while ( ! empty( $desc ) );
	}

	$possible_object_parents = array_filter( $possible_object_parents );

	$front_page_url         = home_url();
	$front_page_id          = (int) get_option( 'page_on_front' );
	$privacy_policy_page_id = (int) get_option( 'wp_page_for_privacy_policy' );

	foreach ( (array) $menu_items as $key => $menu_item ) {

		$menu_items[ $key ]->current = false;

		$classes   = (array) $menu_item->classes;
		$classes[] = 'menu-item';
		$classes[] = 'menu-item-type-' . $menu_item->type;
		$classes[] = 'menu-item-object-' . $menu_item->object;

		// This menu item is set as the 'Front Page'.
		if ( 'post_type' === $menu_item->type && $front_page_id === (int) $menu_item->object_id ) {
			$classes[] = 'menu-item-home';
		}

		// This menu item is set as the 'Privacy Policy Page'.
		if ( 'post_type' === $menu_item->type && $privacy_policy_page_id === (int) $menu_item->object_id ) {
			$classes[] = 'menu-item-privacy-policy';
		}

		// If the menu item corresponds to a taxonomy term for the currently queried non-hierarchical post object.
		if ( $wp_query->is_singular && 'taxonomy' === $menu_item->type
			&& in_array( (int) $menu_item->object_id, $possible_object_parents, true )
		) {
			$active_parent_object_ids[] = (int) $menu_item->object_id;
			$active_parent_item_ids[]   = (int) $menu_item->db_id;
			$active_object              = $queried_object->post_type;

			// If the menu item corresponds to the currently queried post or taxonomy object.
		} elseif (
			$menu_item->object_id == $queried_object_id
			&& (
				( ! empty( $home_page_id ) && 'post_type' === $menu_item->type
					&& $wp_query->is_home && $home_page_id == $menu_item->object_id )
				|| ( 'post_type' === $menu_item->type && $wp_query->is_singular )
				|| ( 'taxonomy' === $menu_item->type
					&& ( $wp_query->is_category || $wp_query->is_tag || $wp_query->is_tax )
					&& $queried_object->taxonomy == $menu_item->object )
			)
		) {
			$classes[]                   = 'current-menu-item';
			$menu_items[ $key ]->current = true;
			$_anc_id                     = (int) $menu_item->db_id;

			while (
				( $_anc_id = (int) get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) )
				&& ! in_array( $_anc_id, $active_ancestor_item_ids, true )
			) {
				$active_ancestor_item_ids[] = $_anc_id;
			}

			if ( 'post_type' === $menu_item->type && 'page' === $menu_item->object ) {
				// Back compat classes for pages to match wp_page_menu().
				$classes[] = 'page_item';
				$classes[] = 'page-item-' . $menu_item->object_id;
				$classes[] = 'current_page_item';
			}

			$active_parent_item_ids[]   = (int) $menu_item->menu_item_parent;
			$active_parent_object_ids[] = (int) $menu_item->post_parent;
			$active_object              = $menu_item->object;

			// If the menu item corresponds to the currently queried post type archive.
		} elseif (
			'post_type_archive' === $menu_item->type
			&& is_post_type_archive( array( $menu_item->object ) )
		) {
			$classes[]                   = 'current-menu-item';
			$menu_items[ $key ]->current = true;
			$_anc_id                     = (int) $menu_item->db_id;

			while (
				( $_anc_id = (int) get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) )
				&& ! in_array( $_anc_id, $active_ancestor_item_ids, true )
			) {
				$active_ancestor_item_ids[] = $_anc_id;
			}

			$active_parent_item_ids[] = (int) $menu_item->menu_item_parent;

			// If the menu item corresponds to the currently requested URL.
		} elseif ( 'custom' === $menu_item->object && isset( $_SERVER['HTTP_HOST'] ) ) {
			$_root_relative_current = untrailingslashit( $_SERVER['REQUEST_URI'] );

			// If it's the customize page then it will strip the query var off the URL before entering the comparison block.
			if ( is_customize_preview() ) {
				$_root_relative_current = strtok( untrailingslashit( $_SERVER['REQUEST_URI'] ), '?' );
			}

			$current_url        = set_url_scheme( 'http://' . $_SERVER['HTTP_HOST'] . $_root_relative_current );
			$raw_item_url       = strpos( $menu_item->url, '#' ) ? substr( $menu_item->url, 0, strpos( $menu_item->url, '#' ) ) : $menu_item->url;
			$item_url           = set_url_scheme( untrailingslashit( $raw_item_url ) );
			$_indexless_current = untrailingslashit( preg_replace( '/' . preg_quote( $wp_rewrite->index, '/' ) . '$/', '', $current_url ) );

			$matches = array(
				$current_url,
				urldecode( $current_url ),
				$_indexless_current,
				urldecode( $_indexless_current ),
				$_root_relative_current,
				urldecode( $_root_relative_current ),
			);

			if ( $raw_item_url && in_array( $item_url, $matches, true ) ) {
				$classes[]                   = 'current-menu-item';
				$menu_items[ $key ]->current = true;
				$_anc_id                     = (int) $menu_item->db_id;

				while (
					( $_anc_id = (int) get_post_meta( $_anc_id, '_menu_item_menu_item_parent', true ) )
					&& ! in_array( $_anc_id, $active_ancestor_item_ids, true )
				) {
					$active_ancestor_item_ids[] = $_anc_id;
				}

				if ( in_array( home_url(), array( untrailingslashit( $current_url ), untrailingslashit( $_indexless_current ) ), true ) ) {
					// Back compat for home link to match wp_page_menu().
					$classes[] = 'current_page_item';
				}
				$active_parent_item_ids[]   = (int) $menu_item->menu_item_parent;
				$active_parent_object_ids[] = (int) $menu_item->post_parent;
				$active_object              = $menu_item->object;

				// Give front page item the 'current-menu-item' class when extra query arguments are involved.
			} elseif ( $item_url == $front_page_url && is_front_page() ) {
				$classes[] = 'current-menu-item';
			}

			if ( untrailingslashit( $item_url ) == home_url() ) {
				$classes[] = 'menu-item-home';
			}
		}

		// Back-compat with wp_page_menu(): add "current_page_parent" to static home page link for any non-page query.
		if ( ! empty( $home_page_id ) && 'post_type' === $menu_item->type
			&& empty( $wp_query->is_page ) && $home_page_id == $menu_item->object_id
		) {
			$classes[] = 'current_page_parent';
		}

		$menu_items[ $key ]->classes = array_unique( $classes );
	}
	$active_ancestor_item_ids = array_filter( array_unique( $active_ancestor_item_ids ) );
	$active_parent_item_ids   = array_filter( array_unique( $active_parent_item_ids ) );
	$active_parent_object_ids = array_filter( array_unique( $active_parent_object_ids ) );

	// Set parent's class.
	foreach ( (array) $menu_items as $key => $parent_item ) {
		$classes                                   = (array) $parent_item->classes;
		$menu_items[ $key ]->current_item_ancestor = false;
		$menu_items[ $key ]->current_item_parent   = false;

		if (
			isset( $parent_item->type )
			&& (
				// Ancestral post object.
				(
					'post_type' === $parent_item->type
					&& ! empty( $queried_object->post_type )
					&& is_post_type_hierarchical( $queried_object->post_type )
					&& in_array( (int) $parent_item->object_id, $queried_object->ancestors, true )
					&& $parent_item->object != $queried_object->ID
				) ||

				// Ancestral term.
				(
					'taxonomy' === $parent_item->type
					&& isset( $possible_taxonomy_ancestors[ $parent_item->object ] )
					&& in_array( (int) $parent_item->object_id, $possible_taxonomy_ancestors[ $parent_item->object ], true )
					&& (
						! isset( $queried_object->term_id ) ||
						$parent_item->object_id != $queried_object->term_id
					)
				)
			)
		) {
			if ( ! empty( $queried_object->taxonomy ) ) {
				$classes[] = 'current-' . $queried_object->taxonomy . '-ancestor';
			} else {
				$classes[] = 'current-' . $queried_object->post_type . '-ancestor';
			}
		}

		if ( in_array( (int) $parent_item->db_id, $active_ancestor_item_ids, true ) ) {
			$classes[] = 'current-menu-ancestor';

			$menu_items[ $key ]->current_item_ancestor = true;
		}
		if ( in_array( (int) $parent_item->db_id, $active_parent_item_ids, true ) ) {
			$classes[] = 'current-menu-parent';

			$menu_items[ $key ]->current_item_parent = true;
		}
		if ( in_array( (int) $parent_item->object_id, $active_parent_object_ids, true ) ) {
			$classes[] = 'current-' . $active_object . '-parent';
		}

		if ( 'post_type' === $parent_item->type && 'page' === $parent_item->object ) {
			// Back compat classes for pages to match wp_page_menu().
			if ( in_array( 'current-menu-parent', $classes, true ) ) {
				$classes[] = 'current_page_parent';
			}
			if ( in_array( 'current-menu-ancestor', $classes, true ) ) {
				$classes[] = 'current_page_ancestor';
			}
		}

		$menu_items[ $key ]->classes = array_unique( $classes );
	}
}

/**
 * Retrieves the HTML list content for nav menu items.
 *
 * @uses Walker_Nav_Menu to create HTML list content.
 * @since 3.0.0
 *
 * @param array    $items The menu items, sorted by each menu item's menu order.
 * @param int      $depth Depth of the item in reference to parents.
 * @param stdClass $r     An object containing wp_nav_menu() arguments.
 * @return string The HTML list content for the menu items.
 */
function walk_nav_menu_tree( $items, $depth, $r ) {
	$walker = ( empty( $r->walker ) ) ? new Walker_Nav_Menu : $r->walker;

	return $walker->walk( $items, $depth, $r );
}

/**
 * Prevents a menu item ID from being used more than once.
 *
 * @since 3.0.1
 * @access private
 *
 * @param string $id
 * @param object $item
 * @return string
 */
function _nav_menu_item_id_use_once( $id, $item ) {
	static $_used_ids = array();

	if ( in_array( $item->ID, $_used_ids, true ) ) {
		return '';
	}

	$_used_ids[] = $item->ID;

	return $id;
}