balmet.com

ms-functions.php (93902B)

---

 <?php
 /**
  * Multisite WordPress API
  *
  * @package WordPress
  * @subpackage Multisite
  * @since 3.0.0
  */
 
 /**
  * Gets the network's site and user counts.
  *
  * @since MU (3.0.0)
  *
  * @return int[] {
  *     Site and user count for the network.
  *
  *     @type int $blogs Number of sites on the network.
  *     @type int $users Number of users on the network.
  * }
  */
 function get_sitestats() {
 	$stats = array(
 		'blogs' => get_blog_count(),
 		'users' => get_user_count(),
 	);
 
 	return $stats;
 }
 
 /**
  * Get one of a user's active blogs
  *
  * Returns the user's primary blog, if they have one and
  * it is active. If it's inactive, function returns another
  * active blog of the user. If none are found, the user
  * is added as a Subscriber to the Dashboard Blog and that blog
  * is returned.
  *
  * @since MU (3.0.0)
  *
  * @param int $user_id The unique ID of the user
  * @return WP_Site|void The blog object
  */
 function get_active_blog_for_user( $user_id ) {
 	$blogs = get_blogs_of_user( $user_id );
 	if ( empty( $blogs ) ) {
 		return;
 	}
 
 	if ( ! is_multisite() ) {
 		return $blogs[ get_current_blog_id() ];
 	}
 
 	$primary_blog = get_user_meta( $user_id, 'primary_blog', true );
 	$first_blog   = current( $blogs );
 	if ( false !== $primary_blog ) {
 		if ( ! isset( $blogs[ $primary_blog ] ) ) {
 			update_user_meta( $user_id, 'primary_blog', $first_blog->userblog_id );
 			$primary = get_site( $first_blog->userblog_id );
 		} else {
 			$primary = get_site( $primary_blog );
 		}
 	} else {
 		// TODO: Review this call to add_user_to_blog too - to get here the user must have a role on this blog?
 		$result = add_user_to_blog( $first_blog->userblog_id, $user_id, 'subscriber' );
 
 		if ( ! is_wp_error( $result ) ) {
 			update_user_meta( $user_id, 'primary_blog', $first_blog->userblog_id );
 			$primary = $first_blog;
 		}
 	}
 
 	if ( ( ! is_object( $primary ) ) || ( 1 == $primary->archived || 1 == $primary->spam || 1 == $primary->deleted ) ) {
 		$blogs = get_blogs_of_user( $user_id, true ); // If a user's primary blog is shut down, check their other blogs.
 		$ret   = false;
 		if ( is_array( $blogs ) && count( $blogs ) > 0 ) {
 			foreach ( (array) $blogs as $blog_id => $blog ) {
 				if ( get_current_network_id() != $blog->site_id ) {
 					continue;
 				}
 				$details = get_site( $blog_id );
 				if ( is_object( $details ) && 0 == $details->archived && 0 == $details->spam && 0 == $details->deleted ) {
 					$ret = $details;
 					if ( get_user_meta( $user_id, 'primary_blog', true ) != $blog_id ) {
 						update_user_meta( $user_id, 'primary_blog', $blog_id );
 					}
 					if ( ! get_user_meta( $user_id, 'source_domain', true ) ) {
 						update_user_meta( $user_id, 'source_domain', $details->domain );
 					}
 					break;
 				}
 			}
 		} else {
 			return;
 		}
 		return $ret;
 	} else {
 		return $primary;
 	}
 }
 
 /**
  * The number of active users in your installation.
  *
  * The count is cached and updated twice daily. This is not a live count.
  *
  * @since MU (3.0.0)
  * @since 4.8.0 The `$network_id` parameter has been added.
  *
  * @param int|null $network_id ID of the network. Default is the current network.
  * @return int Number of active users on the network.
  */
 function get_user_count( $network_id = null ) {
 	return get_network_option( $network_id, 'user_count' );
 }
 
 /**
  * The number of active sites on your installation.
  *
  * The count is cached and updated twice daily. This is not a live count.
  *
  * @since MU (3.0.0)
  * @since 3.7.0 The `$network_id` parameter has been deprecated.
  * @since 4.8.0 The `$network_id` parameter is now being used.
  *
  * @param int|null $network_id ID of the network. Default is the current network.
  * @return int Number of active sites on the network.
  */
 function get_blog_count( $network_id = null ) {
 	return get_network_option( $network_id, 'blog_count' );
 }
 
 /**
  * Gets a blog post from any site on the network.
  *
  * This function is similar to get_post(), except that it can retrieve a post
  * from any site on the network, not just the current site.
  *
  * @since MU (3.0.0)
  *
  * @param int $blog_id ID of the blog.
  * @param int $post_id ID of the post being looked for.
  * @return WP_Post|null WP_Post object on success, null on failure
  */
 function get_blog_post( $blog_id, $post_id ) {
 	switch_to_blog( $blog_id );
 	$post = get_post( $post_id );
 	restore_current_blog();
 
 	return $post;
 }
 
 /**
  * Adds a user to a blog, along with specifying the user's role.
  *
  * Use the {@see 'add_user_to_blog'} action to fire an event when users are added to a blog.
  *
  * @since MU (3.0.0)
  *
  * @param int    $blog_id ID of the blog the user is being added to.
  * @param int    $user_id ID of the user being added.
  * @param string $role    The role you want the user to have.
  * @return true|WP_Error True on success or a WP_Error object if the user doesn't exist
  *                       or could not be added.
  */
 function add_user_to_blog( $blog_id, $user_id, $role ) {
 	switch_to_blog( $blog_id );
 
 	$user = get_userdata( $user_id );
 
 	if ( ! $user ) {
 		restore_current_blog();
 		return new WP_Error( 'user_does_not_exist', __( 'The requested user does not exist.' ) );
 	}
 
 	/**
 	 * Filters whether a user should be added to a site.
 	 *
 	 * @since 4.9.0
 	 *
 	 * @param true|WP_Error $retval  True if the user should be added to the site, error
 	 *                               object otherwise.
 	 * @param int           $user_id User ID.
 	 * @param string        $role    User role.
 	 * @param int           $blog_id Site ID.
 	 */
 	$can_add_user = apply_filters( 'can_add_user_to_blog', true, $user_id, $role, $blog_id );
 
 	if ( true !== $can_add_user ) {
 		restore_current_blog();
 
 		if ( is_wp_error( $can_add_user ) ) {
 			return $can_add_user;
 		}
 
 		return new WP_Error( 'user_cannot_be_added', __( 'User cannot be added to this site.' ) );
 	}
 
 	if ( ! get_user_meta( $user_id, 'primary_blog', true ) ) {
 		update_user_meta( $user_id, 'primary_blog', $blog_id );
 		$site = get_site( $blog_id );
 		update_user_meta( $user_id, 'source_domain', $site->domain );
 	}
 
 	$user->set_role( $role );
 
 	/**
 	 * Fires immediately after a user is added to a site.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param int    $user_id User ID.
 	 * @param string $role    User role.
 	 * @param int    $blog_id Blog ID.
 	 */
 	do_action( 'add_user_to_blog', $user_id, $role, $blog_id );
 
 	clean_user_cache( $user_id );
 	wp_cache_delete( $blog_id . '_user_count', 'blog-details' );
 
 	restore_current_blog();
 
 	return true;
 }
 
 /**
  * Remove a user from a blog.
  *
  * Use the {@see 'remove_user_from_blog'} action to fire an event when
  * users are removed from a blog.
  *
  * Accepts an optional `$reassign` parameter, if you want to
  * reassign the user's blog posts to another user upon removal.
  *
  * @since MU (3.0.0)
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param int $user_id  ID of the user being removed.
  * @param int $blog_id  Optional. ID of the blog the user is being removed from. Default 0.
  * @param int $reassign Optional. ID of the user to whom to reassign posts. Default 0.
  * @return true|WP_Error True on success or a WP_Error object if the user doesn't exist.
  */
 function remove_user_from_blog( $user_id, $blog_id = 0, $reassign = 0 ) {
 	global $wpdb;
 
 	switch_to_blog( $blog_id );
 	$user_id = (int) $user_id;
 
 	/**
 	 * Fires before a user is removed from a site.
 	 *
 	 * @since MU (3.0.0)
 	 * @since 5.4.0 Added the `$reassign` parameter.
 	 *
 	 * @param int $user_id  ID of the user being removed.
 	 * @param int $blog_id  ID of the blog the user is being removed from.
 	 * @param int $reassign ID of the user to whom to reassign posts.
 	 */
 	do_action( 'remove_user_from_blog', $user_id, $blog_id, $reassign );
 
 	// If being removed from the primary blog, set a new primary
 	// if the user is assigned to multiple blogs.
 	$primary_blog = get_user_meta( $user_id, 'primary_blog', true );
 	if ( $primary_blog == $blog_id ) {
 		$new_id     = '';
 		$new_domain = '';
 		$blogs      = get_blogs_of_user( $user_id );
 		foreach ( (array) $blogs as $blog ) {
 			if ( $blog->userblog_id == $blog_id ) {
 				continue;
 			}
 			$new_id     = $blog->userblog_id;
 			$new_domain = $blog->domain;
 			break;
 		}
 
 		update_user_meta( $user_id, 'primary_blog', $new_id );
 		update_user_meta( $user_id, 'source_domain', $new_domain );
 	}
 
 	// wp_revoke_user( $user_id );
 	$user = get_userdata( $user_id );
 	if ( ! $user ) {
 		restore_current_blog();
 		return new WP_Error( 'user_does_not_exist', __( 'That user does not exist.' ) );
 	}
 
 	$user->remove_all_caps();
 
 	$blogs = get_blogs_of_user( $user_id );
 	if ( count( $blogs ) == 0 ) {
 		update_user_meta( $user_id, 'primary_blog', '' );
 		update_user_meta( $user_id, 'source_domain', '' );
 	}
 
 	if ( $reassign ) {
 		$reassign = (int) $reassign;
 		$post_ids = $wpdb->get_col( $wpdb->prepare( "SELECT ID FROM $wpdb->posts WHERE post_author = %d", $user_id ) );
 		$link_ids = $wpdb->get_col( $wpdb->prepare( "SELECT link_id FROM $wpdb->links WHERE link_owner = %d", $user_id ) );
 
 		if ( ! empty( $post_ids ) ) {
 			$wpdb->query( $wpdb->prepare( "UPDATE $wpdb->posts SET post_author = %d WHERE post_author = %d", $reassign, $user_id ) );
 			array_walk( $post_ids, 'clean_post_cache' );
 		}
 
 		if ( ! empty( $link_ids ) ) {
 			$wpdb->query( $wpdb->prepare( "UPDATE $wpdb->links SET link_owner = %d WHERE link_owner = %d", $reassign, $user_id ) );
 			array_walk( $link_ids, 'clean_bookmark_cache' );
 		}
 	}
 
 	restore_current_blog();
 
 	return true;
 }
 
 /**
  * Get the permalink for a post on another blog.
  *
  * @since MU (3.0.0) 1.0
  *
  * @param int $blog_id ID of the source blog.
  * @param int $post_id ID of the desired post.
  * @return string The post's permalink
  */
 function get_blog_permalink( $blog_id, $post_id ) {
 	switch_to_blog( $blog_id );
 	$link = get_permalink( $post_id );
 	restore_current_blog();
 
 	return $link;
 }
 
 /**
  * Get a blog's numeric ID from its URL.
  *
  * On a subdirectory installation like example.com/blog1/,
  * $domain will be the root 'example.com' and $path the
  * subdirectory '/blog1/'. With subdomains like blog1.example.com,
  * $domain is 'blog1.example.com' and $path is '/'.
  *
  * @since MU (3.0.0)
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param string $domain
  * @param string $path   Optional. Not required for subdomain installations.
  * @return int 0 if no blog found, otherwise the ID of the matching blog
  */
 function get_blog_id_from_url( $domain, $path = '/' ) {
 	$domain = strtolower( $domain );
 	$path   = strtolower( $path );
 	$id     = wp_cache_get( md5( $domain . $path ), 'blog-id-cache' );
 
 	if ( -1 == $id ) { // Blog does not exist.
 		return 0;
 	} elseif ( $id ) {
 		return (int) $id;
 	}
 
 	$args   = array(
 		'domain'                 => $domain,
 		'path'                   => $path,
 		'fields'                 => 'ids',
 		'number'                 => 1,
 		'update_site_meta_cache' => false,
 	);
 	$result = get_sites( $args );
 	$id     = array_shift( $result );
 
 	if ( ! $id ) {
 		wp_cache_set( md5( $domain . $path ), -1, 'blog-id-cache' );
 		return 0;
 	}
 
 	wp_cache_set( md5( $domain . $path ), $id, 'blog-id-cache' );
 
 	return $id;
 }
 
 //
 // Admin functions.
 //
 
 /**
  * Checks an email address against a list of banned domains.
  *
  * This function checks against the Banned Email Domains list
  * at wp-admin/network/settings.php. The check is only run on
  * self-registrations; user creation at wp-admin/network/users.php
  * bypasses this check.
  *
  * @since MU (3.0.0)
  *
  * @param string $user_email The email provided by the user at registration.
  * @return bool True when the email address is banned, false otherwise.
  */
 function is_email_address_unsafe( $user_email ) {
 	$banned_names = get_site_option( 'banned_email_domains' );
 	if ( $banned_names && ! is_array( $banned_names ) ) {
 		$banned_names = explode( "\n", $banned_names );
 	}
 
 	$is_email_address_unsafe = false;
 
 	if ( $banned_names && is_array( $banned_names ) && false !== strpos( $user_email, '@', 1 ) ) {
 		$banned_names     = array_map( 'strtolower', $banned_names );
 		$normalized_email = strtolower( $user_email );
 
 		list( $email_local_part, $email_domain ) = explode( '@', $normalized_email );
 
 		foreach ( $banned_names as $banned_domain ) {
 			if ( ! $banned_domain ) {
 				continue;
 			}
 
 			if ( $email_domain == $banned_domain ) {
 				$is_email_address_unsafe = true;
 				break;
 			}
 
 			$dotted_domain = ".$banned_domain";
 			if ( substr( $normalized_email, -strlen( $dotted_domain ) ) === $dotted_domain ) {
 				$is_email_address_unsafe = true;
 				break;
 			}
 		}
 	}
 
 	/**
 	 * Filters whether an email address is unsafe.
 	 *
 	 * @since 3.5.0
 	 *
 	 * @param bool   $is_email_address_unsafe Whether the email address is "unsafe". Default false.
 	 * @param string $user_email              User email address.
 	 */
 	return apply_filters( 'is_email_address_unsafe', $is_email_address_unsafe, $user_email );
 }
 
 /**
  * Sanitize and validate data required for a user sign-up.
  *
  * Verifies the validity and uniqueness of user names and user email addresses,
  * and checks email addresses against allowed and disallowed domains provided by
  * administrators.
  *
  * The {@see 'wpmu_validate_user_signup'} hook provides an easy way to modify the sign-up
  * process. The value $result, which is passed to the hook, contains both the user-provided
  * info and the error messages created by the function. {@see 'wpmu_validate_user_signup'}
  * allows you to process the data in any way you'd like, and unset the relevant errors if
  * necessary.
  *
  * @since MU (3.0.0)
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param string $user_name  The login name provided by the user.
  * @param string $user_email The email provided by the user.
  * @return array {
  *     The array of user name, email, and the error messages.
  *
  *     @type string   $user_name     Sanitized and unique username.
  *     @type string   $orig_username Original username.
  *     @type string   $user_email    User email address.
  *     @type WP_Error $errors        WP_Error object containing any errors found.
  * }
  */
 function wpmu_validate_user_signup( $user_name, $user_email ) {
 	global $wpdb;
 
 	$errors = new WP_Error();
 
 	$orig_username = $user_name;
 	$user_name     = preg_replace( '/\s+/', '', sanitize_user( $user_name, true ) );
 
 	if ( $user_name != $orig_username || preg_match( '/[^a-z0-9]/', $user_name ) ) {
 		$errors->add( 'user_name', __( 'Usernames can only contain lowercase letters (a-z) and numbers.' ) );
 		$user_name = $orig_username;
 	}
 
 	$user_email = sanitize_email( $user_email );
 
 	if ( empty( $user_name ) ) {
 		$errors->add( 'user_name', __( 'Please enter a username.' ) );
 	}
 
 	$illegal_names = get_site_option( 'illegal_names' );
 	if ( ! is_array( $illegal_names ) ) {
 		$illegal_names = array( 'www', 'web', 'root', 'admin', 'main', 'invite', 'administrator' );
 		add_site_option( 'illegal_names', $illegal_names );
 	}
 	if ( in_array( $user_name, $illegal_names, true ) ) {
 		$errors->add( 'user_name', __( 'Sorry, that username is not allowed.' ) );
 	}
 
 	/** This filter is documented in wp-includes/user.php */
 	$illegal_logins = (array) apply_filters( 'illegal_user_logins', array() );
 
 	if ( in_array( strtolower( $user_name ), array_map( 'strtolower', $illegal_logins ), true ) ) {
 		$errors->add( 'user_name', __( 'Sorry, that username is not allowed.' ) );
 	}
 
 	if ( ! is_email( $user_email ) ) {
 		$errors->add( 'user_email', __( 'Please enter a valid email address.' ) );
 	} elseif ( is_email_address_unsafe( $user_email ) ) {
 		$errors->add( 'user_email', __( 'You cannot use that email address to signup. We are having problems with them blocking some of our email. Please use another email provider.' ) );
 	}
 
 	if ( strlen( $user_name ) < 4 ) {
 		$errors->add( 'user_name', __( 'Username must be at least 4 characters.' ) );
 	}
 
 	if ( strlen( $user_name ) > 60 ) {
 		$errors->add( 'user_name', __( 'Username may not be longer than 60 characters.' ) );
 	}
 
 	// All numeric?
 	if ( preg_match( '/^[0-9]*$/', $user_name ) ) {
 		$errors->add( 'user_name', __( 'Sorry, usernames must have letters too!' ) );
 	}
 
 	$limited_email_domains = get_site_option( 'limited_email_domains' );
 	if ( is_array( $limited_email_domains ) && ! empty( $limited_email_domains ) ) {
 		$limited_email_domains = array_map( 'strtolower', $limited_email_domains );
 		$emaildomain           = strtolower( substr( $user_email, 1 + strpos( $user_email, '@' ) ) );
 		if ( ! in_array( $emaildomain, $limited_email_domains, true ) ) {
 			$errors->add( 'user_email', __( 'Sorry, that email address is not allowed!' ) );
 		}
 	}
 
 	// Check if the username has been used already.
 	if ( username_exists( $user_name ) ) {
 		$errors->add( 'user_name', __( 'Sorry, that username already exists!' ) );
 	}
 
 	// Check if the email address has been used already.
 	if ( email_exists( $user_email ) ) {
 		$errors->add( 'user_email', __( 'Sorry, that email address is already used!' ) );
 	}
 
 	// Has someone already signed up for this username?
 	$signup = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->signups WHERE user_login = %s", $user_name ) );
 	if ( $signup instanceof stdClass ) {
 		$registered_at = mysql2date( 'U', $signup->registered );
 		$now           = time();
 		$diff          = $now - $registered_at;
 		// If registered more than two days ago, cancel registration and let this signup go through.
 		if ( $diff > 2 * DAY_IN_SECONDS ) {
 			$wpdb->delete( $wpdb->signups, array( 'user_login' => $user_name ) );
 		} else {
 			$errors->add( 'user_name', __( 'That username is currently reserved but may be available in a couple of days.' ) );
 		}
 	}
 
 	$signup = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->signups WHERE user_email = %s", $user_email ) );
 	if ( $signup instanceof stdClass ) {
 		$diff = time() - mysql2date( 'U', $signup->registered );
 		// If registered more than two days ago, cancel registration and let this signup go through.
 		if ( $diff > 2 * DAY_IN_SECONDS ) {
 			$wpdb->delete( $wpdb->signups, array( 'user_email' => $user_email ) );
 		} else {
 			$errors->add( 'user_email', __( 'That email address has already been used. Please check your inbox for an activation email. It will become available in a couple of days if you do nothing.' ) );
 		}
 	}
 
 	$result = array(
 		'user_name'     => $user_name,
 		'orig_username' => $orig_username,
 		'user_email'    => $user_email,
 		'errors'        => $errors,
 	);
 
 	/**
 	 * Filters the validated user registration details.
 	 *
 	 * This does not allow you to override the username or email of the user during
 	 * registration. The values are solely used for validation and error handling.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param array $result {
 	 *     The array of user name, email, and the error messages.
 	 *
 	 *     @type string   $user_name     Sanitized and unique username.
 	 *     @type string   $orig_username Original username.
 	 *     @type string   $user_email    User email address.
 	 *     @type WP_Error $errors        WP_Error object containing any errors found.
 	 * }
 	 */
 	return apply_filters( 'wpmu_validate_user_signup', $result );
 }
 
 /**
  * Processes new site registrations.
  *
  * Checks the data provided by the user during blog signup. Verifies
  * the validity and uniqueness of blog paths and domains.
  *
  * This function prevents the current user from registering a new site
  * with a blogname equivalent to another user's login name. Passing the
  * $user parameter to the function, where $user is the other user, is
  * effectively an override of this limitation.
  *
  * Filter {@see 'wpmu_validate_blog_signup'} if you want to modify
  * the way that WordPress validates new site signups.
  *
  * @since MU (3.0.0)
  *
  * @global wpdb   $wpdb   WordPress database abstraction object.
  * @global string $domain
  *
  * @param string         $blogname   The blog name provided by the user. Must be unique.
  * @param string         $blog_title The blog title provided by the user.
  * @param WP_User|string $user       Optional. The user object to check against the new site name.
  * @return array {
  *     Array of domain, path, blog name, blog title, user and error messages.
  *
  *     @type string         $domain     Domain for the site.
  *     @type string         $path       Path for the site. Used in subdirectory installations.
  *     @type string         $blogname   The unique site name (slug).
  *     @type string         $blog_title Blog title.
  *     @type string|WP_User $user       By default, an empty string. A user object if provided.
  *     @type WP_Error       $errors     WP_Error containing any errors found.
  * }
  */
 function wpmu_validate_blog_signup( $blogname, $blog_title, $user = '' ) {
 	global $wpdb, $domain;
 
 	$current_network = get_network();
 	$base            = $current_network->path;
 
 	$blog_title = strip_tags( $blog_title );
 
 	$errors        = new WP_Error();
 	$illegal_names = get_site_option( 'illegal_names' );
 	if ( false == $illegal_names ) {
 		$illegal_names = array( 'www', 'web', 'root', 'admin', 'main', 'invite', 'administrator' );
 		add_site_option( 'illegal_names', $illegal_names );
 	}
 
 	/*
 	 * On sub dir installations, some names are so illegal, only a filter can
 	 * spring them from jail.
 	 */
 	if ( ! is_subdomain_install() ) {
 		$illegal_names = array_merge( $illegal_names, get_subdirectory_reserved_names() );
 	}
 
 	if ( empty( $blogname ) ) {
 		$errors->add( 'blogname', __( 'Please enter a site name.' ) );
 	}
 
 	if ( preg_match( '/[^a-z0-9]+/', $blogname ) ) {
 		$errors->add( 'blogname', __( 'Site names can only contain lowercase letters (a-z) and numbers.' ) );
 	}
 
 	if ( in_array( $blogname, $illegal_names, true ) ) {
 		$errors->add( 'blogname', __( 'That name is not allowed.' ) );
 	}
 
 	/**
 	 * Filters the minimum site name length required when validating a site signup.
 	 *
 	 * @since 4.8.0
 	 *
 	 * @param int $length The minimum site name length. Default 4.
 	 */
 	$minimum_site_name_length = apply_filters( 'minimum_site_name_length', 4 );
 
 	if ( strlen( $blogname ) < $minimum_site_name_length ) {
 		/* translators: %s: Minimum site name length. */
 		$errors->add( 'blogname', sprintf( _n( 'Site name must be at least %s character.', 'Site name must be at least %s characters.', $minimum_site_name_length ), number_format_i18n( $minimum_site_name_length ) ) );
 	}
 
 	// Do not allow users to create a blog that conflicts with a page on the main blog.
 	if ( ! is_subdomain_install() && $wpdb->get_var( $wpdb->prepare( 'SELECT post_name FROM ' . $wpdb->get_blog_prefix( $current_network->site_id ) . "posts WHERE post_type = 'page' AND post_name = %s", $blogname ) ) ) {
 		$errors->add( 'blogname', __( 'Sorry, you may not use that site name.' ) );
 	}
 
 	// All numeric?
 	if ( preg_match( '/^[0-9]*$/', $blogname ) ) {
 		$errors->add( 'blogname', __( 'Sorry, site names must have letters too!' ) );
 	}
 
 	/**
 	 * Filters the new site name during registration.
 	 *
 	 * The name is the site's subdomain or the site's subdirectory
 	 * path depending on the network settings.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param string $blogname Site name.
 	 */
 	$blogname = apply_filters( 'newblogname', $blogname );
 
 	$blog_title = wp_unslash( $blog_title );
 
 	if ( empty( $blog_title ) ) {
 		$errors->add( 'blog_title', __( 'Please enter a site title.' ) );
 	}
 
 	// Check if the domain/path has been used already.
 	if ( is_subdomain_install() ) {
 		$mydomain = $blogname . '.' . preg_replace( '|^www\.|', '', $domain );
 		$path     = $base;
 	} else {
 		$mydomain = $domain;
 		$path     = $base . $blogname . '/';
 	}
 	if ( domain_exists( $mydomain, $path, $current_network->id ) ) {
 		$errors->add( 'blogname', __( 'Sorry, that site already exists!' ) );
 	}
 
 	if ( username_exists( $blogname ) ) {
 		if ( ! is_object( $user ) || ( is_object( $user ) && ( $user->user_login != $blogname ) ) ) {
 			$errors->add( 'blogname', __( 'Sorry, that site is reserved!' ) );
 		}
 	}
 
 	// Has someone already signed up for this domain?
 	// TODO: Check email too?
 	$signup = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->signups WHERE domain = %s AND path = %s", $mydomain, $path ) );
 	if ( $signup instanceof stdClass ) {
 		$diff = time() - mysql2date( 'U', $signup->registered );
 		// If registered more than two days ago, cancel registration and let this signup go through.
 		if ( $diff > 2 * DAY_IN_SECONDS ) {
 			$wpdb->delete(
 				$wpdb->signups,
 				array(
 					'domain' => $mydomain,
 					'path'   => $path,
 				)
 			);
 		} else {
 			$errors->add( 'blogname', __( 'That site is currently reserved but may be available in a couple days.' ) );
 		}
 	}
 
 	$result = array(
 		'domain'     => $mydomain,
 		'path'       => $path,
 		'blogname'   => $blogname,
 		'blog_title' => $blog_title,
 		'user'       => $user,
 		'errors'     => $errors,
 	);
 
 	/**
 	 * Filters site details and error messages following registration.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param array $result {
 	 *     Array of domain, path, blog name, blog title, user and error messages.
 	 *
 	 *     @type string         $domain     Domain for the site.
 	 *     @type string         $path       Path for the site. Used in subdirectory installations.
 	 *     @type string         $blogname   The unique site name (slug).
 	 *     @type string         $blog_title Blog title.
 	 *     @type string|WP_User $user       By default, an empty string. A user object if provided.
 	 *     @type WP_Error       $errors     WP_Error containing any errors found.
 	 * }
 	 */
 	return apply_filters( 'wpmu_validate_blog_signup', $result );
 }
 
 /**
  * Record site signup information for future activation.
  *
  * @since MU (3.0.0)
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param string $domain     The requested domain.
  * @param string $path       The requested path.
  * @param string $title      The requested site title.
  * @param string $user       The user's requested login name.
  * @param string $user_email The user's email address.
  * @param array  $meta       Optional. Signup meta data. By default, contains the requested privacy setting and lang_id.
  */
 function wpmu_signup_blog( $domain, $path, $title, $user, $user_email, $meta = array() ) {
 	global $wpdb;
 
 	$key = substr( md5( time() . wp_rand() . $domain ), 0, 16 );
 
 	/**
 	 * Filters the metadata for a site signup.
 	 *
 	 * The metadata will be serialized prior to storing it in the database.
 	 *
 	 * @since 4.8.0
 	 *
 	 * @param array  $meta       Signup meta data. Default empty array.
 	 * @param string $domain     The requested domain.
 	 * @param string $path       The requested path.
 	 * @param string $title      The requested site title.
 	 * @param string $user       The user's requested login name.
 	 * @param string $user_email The user's email address.
 	 * @param string $key        The user's activation key.
 	 */
 	$meta = apply_filters( 'signup_site_meta', $meta, $domain, $path, $title, $user, $user_email, $key );
 
 	$wpdb->insert(
 		$wpdb->signups,
 		array(
 			'domain'         => $domain,
 			'path'           => $path,
 			'title'          => $title,
 			'user_login'     => $user,
 			'user_email'     => $user_email,
 			'registered'     => current_time( 'mysql', true ),
 			'activation_key' => $key,
 			'meta'           => serialize( $meta ),
 		)
 	);
 
 	/**
 	 * Fires after site signup information has been written to the database.
 	 *
 	 * @since 4.4.0
 	 *
 	 * @param string $domain     The requested domain.
 	 * @param string $path       The requested path.
 	 * @param string $title      The requested site title.
 	 * @param string $user       The user's requested login name.
 	 * @param string $user_email The user's email address.
 	 * @param string $key        The user's activation key.
 	 * @param array  $meta       Signup meta data. By default, contains the requested privacy setting and lang_id.
 	 */
 	do_action( 'after_signup_site', $domain, $path, $title, $user, $user_email, $key, $meta );
 }
 
 /**
  * Record user signup information for future activation.
  *
  * This function is used when user registration is open but
  * new site registration is not.
  *
  * @since MU (3.0.0)
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param string $user       The user's requested login name.
  * @param string $user_email The user's email address.
  * @param array  $meta       Optional. Signup meta data. Default empty array.
  */
 function wpmu_signup_user( $user, $user_email, $meta = array() ) {
 	global $wpdb;
 
 	// Format data.
 	$user       = preg_replace( '/\s+/', '', sanitize_user( $user, true ) );
 	$user_email = sanitize_email( $user_email );
 	$key        = substr( md5( time() . wp_rand() . $user_email ), 0, 16 );
 
 	/**
 	 * Filters the metadata for a user signup.
 	 *
 	 * The metadata will be serialized prior to storing it in the database.
 	 *
 	 * @since 4.8.0
 	 *
 	 * @param array  $meta       Signup meta data. Default empty array.
 	 * @param string $user       The user's requested login name.
 	 * @param string $user_email The user's email address.
 	 * @param string $key        The user's activation key.
 	 */
 	$meta = apply_filters( 'signup_user_meta', $meta, $user, $user_email, $key );
 
 	$wpdb->insert(
 		$wpdb->signups,
 		array(
 			'domain'         => '',
 			'path'           => '',
 			'title'          => '',
 			'user_login'     => $user,
 			'user_email'     => $user_email,
 			'registered'     => current_time( 'mysql', true ),
 			'activation_key' => $key,
 			'meta'           => serialize( $meta ),
 		)
 	);
 
 	/**
 	 * Fires after a user's signup information has been written to the database.
 	 *
 	 * @since 4.4.0
 	 *
 	 * @param string $user       The user's requested login name.
 	 * @param string $user_email The user's email address.
 	 * @param string $key        The user's activation key.
 	 * @param array  $meta       Signup meta data. Default empty array.
 	 */
 	do_action( 'after_signup_user', $user, $user_email, $key, $meta );
 }
 
 /**
  * Send a confirmation request email to a user when they sign up for a new site. The new site will not become active
  * until the confirmation link is clicked.
  *
  * This is the notification function used when site registration
  * is enabled.
  *
  * Filter {@see 'wpmu_signup_blog_notification'} to bypass this function or
  * replace it with your own notification behavior.
  *
  * Filter {@see 'wpmu_signup_blog_notification_email'} and
  * {@see 'wpmu_signup_blog_notification_subject'} to change the content
  * and subject line of the email sent to newly registered users.
  *
  * @since MU (3.0.0)
  *
  * @param string $domain     The new blog domain.
  * @param string $path       The new blog path.
  * @param string $title      The site title.
  * @param string $user_login The user's login name.
  * @param string $user_email The user's email address.
  * @param string $key        The activation key created in wpmu_signup_blog()
  * @param array  $meta       Optional. Signup meta data. By default, contains the requested privacy setting and lang_id.
  * @return bool
  */
 function wpmu_signup_blog_notification( $domain, $path, $title, $user_login, $user_email, $key, $meta = array() ) {
 	/**
 	 * Filters whether to bypass the new site email notification.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param string|false $domain     Site domain, or false to prevent the email from sending.
 	 * @param string       $path       Site path.
 	 * @param string       $title      Site title.
 	 * @param string       $user_login User login name.
 	 * @param string       $user_email User email address.
 	 * @param string       $key        Activation key created in wpmu_signup_blog().
 	 * @param array        $meta       Signup meta data. By default, contains the requested privacy setting and lang_id.
 	 */
 	if ( ! apply_filters( 'wpmu_signup_blog_notification', $domain, $path, $title, $user_login, $user_email, $key, $meta ) ) {
 		return false;
 	}
 
 	// Send email with activation link.
 	if ( ! is_subdomain_install() || get_current_network_id() != 1 ) {
 		$activate_url = network_site_url( "wp-activate.php?key=$key" );
 	} else {
 		$activate_url = "http://{$domain}{$path}wp-activate.php?key=$key"; // @todo Use *_url() API.
 	}
 
 	$activate_url = esc_url( $activate_url );
 
 	$admin_email = get_site_option( 'admin_email' );
 
 	if ( '' === $admin_email ) {
 		$admin_email = 'support@' . wp_parse_url( network_home_url(), PHP_URL_HOST );
 	}
 
 	$from_name       = ( '' !== get_site_option( 'site_name' ) ) ? esc_html( get_site_option( 'site_name' ) ) : 'WordPress';
 	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . 'Content-Type: text/plain; charset="' . get_option( 'blog_charset' ) . "\"\n";
 
 	$user            = get_user_by( 'login', $user_login );
 	$switched_locale = switch_to_locale( get_user_locale( $user ) );
 
 	$message = sprintf(
 		/**
 		 * Filters the message content of the new blog notification email.
 		 *
 		 * Content should be formatted for transmission via wp_mail().
 		 *
 		 * @since MU (3.0.0)
 		 *
 		 * @param string $content    Content of the notification email.
 		 * @param string $domain     Site domain.
 		 * @param string $path       Site path.
 		 * @param string $title      Site title.
 		 * @param string $user_login User login name.
 		 * @param string $user_email User email address.
 		 * @param string $key        Activation key created in wpmu_signup_blog().
 		 * @param array  $meta       Signup meta data. By default, contains the requested privacy setting and lang_id.
 		 */
 		apply_filters(
 			'wpmu_signup_blog_notification_email',
 			/* translators: New site notification email. 1: Activation URL, 2: New site URL. */
 			__( "To activate your blog, please click the following link:\n\n%1\$s\n\nAfter you activate, you will receive *another email* with your login.\n\nAfter you activate, you can visit your site here:\n\n%2\$s" ),
 			$domain,
 			$path,
 			$title,
 			$user_login,
 			$user_email,
 			$key,
 			$meta
 		),
 		$activate_url,
 		esc_url( "http://{$domain}{$path}" ),
 		$key
 	);
 
 	$subject = sprintf(
 		/**
 		 * Filters the subject of the new blog notification email.
 		 *
 		 * @since MU (3.0.0)
 		 *
 		 * @param string $subject    Subject of the notification email.
 		 * @param string $domain     Site domain.
 		 * @param string $path       Site path.
 		 * @param string $title      Site title.
 		 * @param string $user_login User login name.
 		 * @param string $user_email User email address.
 		 * @param string $key        Activation key created in wpmu_signup_blog().
 		 * @param array  $meta       Signup meta data. By default, contains the requested privacy setting and lang_id.
 		 */
 		apply_filters(
 			'wpmu_signup_blog_notification_subject',
 			/* translators: New site notification email subject. 1: Network title, 2: New site URL. */
 			_x( '[%1$s] Activate %2$s', 'New site notification email subject' ),
 			$domain,
 			$path,
 			$title,
 			$user_login,
 			$user_email,
 			$key,
 			$meta
 		),
 		$from_name,
 		esc_url( 'http://' . $domain . $path )
 	);
 
 	wp_mail( $user_email, wp_specialchars_decode( $subject ), $message, $message_headers );
 
 	if ( $switched_locale ) {
 		restore_previous_locale();
 	}
 
 	return true;
 }
 
 /**
  * Send a confirmation request email to a user when they sign up for a new user account (without signing up for a site
  * at the same time). The user account will not become active until the confirmation link is clicked.
  *
  * This is the notification function used when no new site has
  * been requested.
  *
  * Filter {@see 'wpmu_signup_user_notification'} to bypass this function or
  * replace it with your own notification behavior.
  *
  * Filter {@see 'wpmu_signup_user_notification_email'} and
  * {@see 'wpmu_signup_user_notification_subject'} to change the content
  * and subject line of the email sent to newly registered users.
  *
  * @since MU (3.0.0)
  *
  * @param string $user_login The user's login name.
  * @param string $user_email The user's email address.
  * @param string $key        The activation key created in wpmu_signup_user()
  * @param array  $meta       Optional. Signup meta data. Default empty array.
  * @return bool
  */
 function wpmu_signup_user_notification( $user_login, $user_email, $key, $meta = array() ) {
 	/**
 	 * Filters whether to bypass the email notification for new user sign-up.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param string $user_login User login name.
 	 * @param string $user_email User email address.
 	 * @param string $key        Activation key created in wpmu_signup_user().
 	 * @param array  $meta       Signup meta data. Default empty array.
 	 */
 	if ( ! apply_filters( 'wpmu_signup_user_notification', $user_login, $user_email, $key, $meta ) ) {
 		return false;
 	}
 
 	$user            = get_user_by( 'login', $user_login );
 	$switched_locale = switch_to_locale( get_user_locale( $user ) );
 
 	// Send email with activation link.
 	$admin_email = get_site_option( 'admin_email' );
 
 	if ( '' === $admin_email ) {
 		$admin_email = 'support@' . wp_parse_url( network_home_url(), PHP_URL_HOST );
 	}
 
 	$from_name       = ( '' !== get_site_option( 'site_name' ) ) ? esc_html( get_site_option( 'site_name' ) ) : 'WordPress';
 	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . 'Content-Type: text/plain; charset="' . get_option( 'blog_charset' ) . "\"\n";
 	$message         = sprintf(
 		/**
 		 * Filters the content of the notification email for new user sign-up.
 		 *
 		 * Content should be formatted for transmission via wp_mail().
 		 *
 		 * @since MU (3.0.0)
 		 *
 		 * @param string $content    Content of the notification email.
 		 * @param string $user_login User login name.
 		 * @param string $user_email User email address.
 		 * @param string $key        Activation key created in wpmu_signup_user().
 		 * @param array  $meta       Signup meta data. Default empty array.
 		 */
 		apply_filters(
 			'wpmu_signup_user_notification_email',
 			/* translators: New user notification email. %s: Activation URL. */
 			__( "To activate your user, please click the following link:\n\n%s\n\nAfter you activate, you will receive *another email* with your login." ),
 			$user_login,
 			$user_email,
 			$key,
 			$meta
 		),
 		site_url( "wp-activate.php?key=$key" )
 	);
 
 	$subject = sprintf(
 		/**
 		 * Filters the subject of the notification email of new user signup.
 		 *
 		 * @since MU (3.0.0)
 		 *
 		 * @param string $subject    Subject of the notification email.
 		 * @param string $user_login User login name.
 		 * @param string $user_email User email address.
 		 * @param string $key        Activation key created in wpmu_signup_user().
 		 * @param array  $meta       Signup meta data. Default empty array.
 		 */
 		apply_filters(
 			'wpmu_signup_user_notification_subject',
 			/* translators: New user notification email subject. 1: Network title, 2: New user login. */
 			_x( '[%1$s] Activate %2$s', 'New user notification email subject' ),
 			$user_login,
 			$user_email,
 			$key,
 			$meta
 		),
 		$from_name,
 		$user_login
 	);
 
 	wp_mail( $user_email, wp_specialchars_decode( $subject ), $message, $message_headers );
 
 	if ( $switched_locale ) {
 		restore_previous_locale();
 	}
 
 	return true;
 }
 
 /**
  * Activate a signup.
  *
  * Hook to {@see 'wpmu_activate_user'} or {@see 'wpmu_activate_blog'} for events
  * that should happen only when users or sites are self-created (since
  * those actions are not called when users and sites are created
  * by a Super Admin).
  *
  * @since MU (3.0.0)
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param string $key The activation key provided to the user.
  * @return array|WP_Error An array containing information about the activated user and/or blog
  */
 function wpmu_activate_signup( $key ) {
 	global $wpdb;
 
 	$signup = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->signups WHERE activation_key = %s", $key ) );
 
 	if ( empty( $signup ) ) {
 		return new WP_Error( 'invalid_key', __( 'Invalid activation key.' ) );
 	}
 
 	if ( $signup->active ) {
 		if ( empty( $signup->domain ) ) {
 			return new WP_Error( 'already_active', __( 'The user is already active.' ), $signup );
 		} else {
 			return new WP_Error( 'already_active', __( 'The site is already active.' ), $signup );
 		}
 	}
 
 	$meta     = maybe_unserialize( $signup->meta );
 	$password = wp_generate_password( 12, false );
 
 	$user_id = username_exists( $signup->user_login );
 
 	if ( ! $user_id ) {
 		$user_id = wpmu_create_user( $signup->user_login, $password, $signup->user_email );
 	} else {
 		$user_already_exists = true;
 	}
 
 	if ( ! $user_id ) {
 		return new WP_Error( 'create_user', __( 'Could not create user' ), $signup );
 	}
 
 	$now = current_time( 'mysql', true );
 
 	if ( empty( $signup->domain ) ) {
 		$wpdb->update(
 			$wpdb->signups,
 			array(
 				'active'    => 1,
 				'activated' => $now,
 			),
 			array( 'activation_key' => $key )
 		);
 
 		if ( isset( $user_already_exists ) ) {
 			return new WP_Error( 'user_already_exists', __( 'That username is already activated.' ), $signup );
 		}
 
 		/**
 		 * Fires immediately after a new user is activated.
 		 *
 		 * @since MU (3.0.0)
 		 *
 		 * @param int    $user_id  User ID.
 		 * @param string $password User password.
 		 * @param array  $meta     Signup meta data.
 		 */
 		do_action( 'wpmu_activate_user', $user_id, $password, $meta );
 
 		return array(
 			'user_id'  => $user_id,
 			'password' => $password,
 			'meta'     => $meta,
 		);
 	}
 
 	$blog_id = wpmu_create_blog( $signup->domain, $signup->path, $signup->title, $user_id, $meta, get_current_network_id() );
 
 	// TODO: What to do if we create a user but cannot create a blog?
 	if ( is_wp_error( $blog_id ) ) {
 		/*
 		 * If blog is taken, that means a previous attempt to activate this blog
 		 * failed in between creating the blog and setting the activation flag.
 		 * Let's just set the active flag and instruct the user to reset their password.
 		 */
 		if ( 'blog_taken' === $blog_id->get_error_code() ) {
 			$blog_id->add_data( $signup );
 			$wpdb->update(
 				$wpdb->signups,
 				array(
 					'active'    => 1,
 					'activated' => $now,
 				),
 				array( 'activation_key' => $key )
 			);
 		}
 		return $blog_id;
 	}
 
 	$wpdb->update(
 		$wpdb->signups,
 		array(
 			'active'    => 1,
 			'activated' => $now,
 		),
 		array( 'activation_key' => $key )
 	);
 
 	/**
 	 * Fires immediately after a site is activated.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param int    $blog_id       Blog ID.
 	 * @param int    $user_id       User ID.
 	 * @param int    $password      User password.
 	 * @param string $signup_title  Site title.
 	 * @param array  $meta          Signup meta data. By default, contains the requested privacy setting and lang_id.
 	 */
 	do_action( 'wpmu_activate_blog', $blog_id, $user_id, $password, $signup->title, $meta );
 
 	return array(
 		'blog_id'  => $blog_id,
 		'user_id'  => $user_id,
 		'password' => $password,
 		'title'    => $signup->title,
 		'meta'     => $meta,
 	);
 }
 
 /**
  * Deletes am associated signup entry when a user is deleted from the database.
  *
  * @since 5.5.0
  *
  * @param int      $id       ID of the user to delete.
  * @param int|null $reassign ID of the user to reassign posts and links to.
  * @param WP_User  $user     User object.
  */
 function wp_delete_signup_on_user_delete( $id, $reassign, $user ) {
 	global $wpdb;
 
 	$wpdb->delete( $wpdb->signups, array( 'user_login' => $user->user_login ) );
 }
 
 /**
  * Create a user.
  *
  * This function runs when a user self-registers as well as when
  * a Super Admin creates a new user. Hook to {@see 'wpmu_new_user'} for events
  * that should affect all new users, but only on Multisite (otherwise
  * use {@see'user_register'}).
  *
  * @since MU (3.0.0)
  *
  * @param string $user_name The new user's login name.
  * @param string $password  The new user's password.
  * @param string $email     The new user's email address.
  * @return int|false Returns false on failure, or int $user_id on success
  */
 function wpmu_create_user( $user_name, $password, $email ) {
 	$user_name = preg_replace( '/\s+/', '', sanitize_user( $user_name, true ) );
 
 	$user_id = wp_create_user( $user_name, $password, $email );
 	if ( is_wp_error( $user_id ) ) {
 		return false;
 	}
 
 	// Newly created users have no roles or caps until they are added to a blog.
 	delete_user_option( $user_id, 'capabilities' );
 	delete_user_option( $user_id, 'user_level' );
 
 	/**
 	 * Fires immediately after a new user is created.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param int $user_id User ID.
 	 */
 	do_action( 'wpmu_new_user', $user_id );
 
 	return $user_id;
 }
 
 /**
  * Create a site.
  *
  * This function runs when a user self-registers a new site as well
  * as when a Super Admin creates a new site. Hook to {@see 'wpmu_new_blog'}
  * for events that should affect all new sites.
  *
  * On subdirectory installations, $domain is the same as the main site's
  * domain, and the path is the subdirectory name (eg 'example.com'
  * and '/blog1/'). On subdomain installations, $domain is the new subdomain +
  * root domain (eg 'blog1.example.com'), and $path is '/'.
  *
  * @since MU (3.0.0)
  *
  * @param string $domain     The new site's domain.
  * @param string $path       The new site's path.
  * @param string $title      The new site's title.
  * @param int    $user_id    The user ID of the new site's admin.
  * @param array  $options    Optional. Array of key=>value pairs used to set initial site options.
  *                           If valid status keys are included ('public', 'archived', 'mature',
  *                           'spam', 'deleted', or 'lang_id') the given site status(es) will be
  *                           updated. Otherwise, keys and values will be used to set options for
  *                           the new site. Default empty array.
  * @param int    $network_id Optional. Network ID. Only relevant on multi-network installations.
  * @return int|WP_Error Returns WP_Error object on failure, the new site ID on success.
  */
 function wpmu_create_blog( $domain, $path, $title, $user_id, $options = array(), $network_id = 1 ) {
 	$defaults = array(
 		'public' => 0,
 	);
 	$options  = wp_parse_args( $options, $defaults );
 
 	$title   = strip_tags( $title );
 	$user_id = (int) $user_id;
 
 	// Check if the domain has been used already. We should return an error message.
 	if ( domain_exists( $domain, $path, $network_id ) ) {
 		return new WP_Error( 'blog_taken', __( 'Sorry, that site already exists!' ) );
 	}
 
 	if ( ! wp_installing() ) {
 		wp_installing( true );
 	}
 
 	$allowed_data_fields = array( 'public', 'archived', 'mature', 'spam', 'deleted', 'lang_id' );
 
 	$site_data = array_merge(
 		array(
 			'domain'     => $domain,
 			'path'       => $path,
 			'network_id' => $network_id,
 		),
 		array_intersect_key( $options, array_flip( $allowed_data_fields ) )
 	);
 
 	// Data to pass to wp_initialize_site().
 	$site_initialization_data = array(
 		'title'   => $title,
 		'user_id' => $user_id,
 		'options' => array_diff_key( $options, array_flip( $allowed_data_fields ) ),
 	);
 
 	$blog_id = wp_insert_site( array_merge( $site_data, $site_initialization_data ) );
 
 	if ( is_wp_error( $blog_id ) ) {
 		return $blog_id;
 	}
 
 	wp_cache_set( 'last_changed', microtime(), 'sites' );
 
 	return $blog_id;
 }
 
 /**
  * Notifies the network admin that a new site has been activated.
  *
  * Filter {@see 'newblog_notify_siteadmin'} to change the content of
  * the notification email.
  *
  * @since MU (3.0.0)
  * @since 5.1.0 $blog_id now supports input from the {@see 'wp_initialize_site'} action.
  *
  * @param WP_Site|int $blog_id    The new site's object or ID.
  * @param string      $deprecated Not used.
  * @return bool
  */
 function newblog_notify_siteadmin( $blog_id, $deprecated = '' ) {
 	if ( is_object( $blog_id ) ) {
 		$blog_id = $blog_id->blog_id;
 	}
 
 	if ( 'yes' !== get_site_option( 'registrationnotification' ) ) {
 		return false;
 	}
 
 	$email = get_site_option( 'admin_email' );
 
 	if ( is_email( $email ) == false ) {
 		return false;
 	}
 
 	$options_site_url = esc_url( network_admin_url( 'settings.php' ) );
 
 	switch_to_blog( $blog_id );
 	$blogname = get_option( 'blogname' );
 	$siteurl  = site_url();
 	restore_current_blog();
 
 	$msg = sprintf(
 		/* translators: New site notification email. 1: Site URL, 2: User IP address, 3: URL to Network Settings screen. */
 		__(
 			'New Site: %1$s
 URL: %2$s
 Remote IP address: %3$s
 
 Disable these notifications: %4$s'
 		),
 		$blogname,
 		$siteurl,
 		wp_unslash( $_SERVER['REMOTE_ADDR'] ),
 		$options_site_url
 	);
 	/**
 	 * Filters the message body of the new site activation email sent
 	 * to the network administrator.
 	 *
 	 * @since MU (3.0.0)
 	 * @since 5.4.0 The `$blog_id` parameter was added.
 	 *
 	 * @param string $msg     Email body.
 	 * @param int    $blog_id The new site's ID.
 	 */
 	$msg = apply_filters( 'newblog_notify_siteadmin', $msg, $blog_id );
 
 	/* translators: New site notification email subject. %s: New site URL. */
 	wp_mail( $email, sprintf( __( 'New Site Registration: %s' ), $siteurl ), $msg );
 
 	return true;
 }
 
 /**
  * Notifies the network admin that a new user has been activated.
  *
  * Filter {@see 'newuser_notify_siteadmin'} to change the content of
  * the notification email.
  *
  * @since MU (3.0.0)
  *
  * @param int $user_id The new user's ID.
  * @return bool
  */
 function newuser_notify_siteadmin( $user_id ) {
 	if ( 'yes' !== get_site_option( 'registrationnotification' ) ) {
 		return false;
 	}
 
 	$email = get_site_option( 'admin_email' );
 
 	if ( is_email( $email ) == false ) {
 		return false;
 	}
 
 	$user = get_userdata( $user_id );
 
 	$options_site_url = esc_url( network_admin_url( 'settings.php' ) );
 
 	$msg = sprintf(
 		/* translators: New user notification email. 1: User login, 2: User IP address, 3: URL to Network Settings screen. */
 		__(
 			'New User: %1$s
 Remote IP address: %2$s
 
 Disable these notifications: %3$s'
 		),
 		$user->user_login,
 		wp_unslash( $_SERVER['REMOTE_ADDR'] ),
 		$options_site_url
 	);
 
 	/**
 	 * Filters the message body of the new user activation email sent
 	 * to the network administrator.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param string  $msg  Email body.
 	 * @param WP_User $user WP_User instance of the new user.
 	 */
 	$msg = apply_filters( 'newuser_notify_siteadmin', $msg, $user );
 
 	/* translators: New user notification email subject. %s: User login. */
 	wp_mail( $email, sprintf( __( 'New User Registration: %s' ), $user->user_login ), $msg );
 
 	return true;
 }
 
 /**
  * Checks whether a site name is already taken.
  *
  * The name is the site's subdomain or the site's subdirectory
  * path depending on the network settings.
  *
  * Used during the new site registration process to ensure
  * that each site name is unique.
  *
  * @since MU (3.0.0)
  *
  * @param string $domain     The domain to be checked.
  * @param string $path       The path to be checked.
  * @param int    $network_id Optional. Network ID. Relevant only on multi-network installations.
  * @return int|null The site ID if the site name exists, null otherwise.
  */
 function domain_exists( $domain, $path, $network_id = 1 ) {
 	$path   = trailingslashit( $path );
 	$args   = array(
 		'network_id'             => $network_id,
 		'domain'                 => $domain,
 		'path'                   => $path,
 		'fields'                 => 'ids',
 		'number'                 => 1,
 		'update_site_meta_cache' => false,
 	);
 	$result = get_sites( $args );
 	$result = array_shift( $result );
 
 	/**
 	 * Filters whether a site name is taken.
 	 *
 	 * The name is the site's subdomain or the site's subdirectory
 	 * path depending on the network settings.
 	 *
 	 * @since 3.5.0
 	 *
 	 * @param int|null $result     The site ID if the site name exists, null otherwise.
 	 * @param string   $domain     Domain to be checked.
 	 * @param string   $path       Path to be checked.
 	 * @param int      $network_id Network ID. Relevant only on multi-network installations.
 	 */
 	return apply_filters( 'domain_exists', $result, $domain, $path, $network_id );
 }
 
 /**
  * Notifies the site administrator that their site activation was successful.
  *
  * Filter {@see 'wpmu_welcome_notification'} to disable or bypass.
  *
  * Filter {@see 'update_welcome_email'} and {@see 'update_welcome_subject'} to
  * modify the content and subject line of the notification email.
  *
  * @since MU (3.0.0)
  *
  * @param int    $blog_id  Site ID.
  * @param int    $user_id  User ID.
  * @param string $password User password, or "N/A" if the user account is not new.
  * @param string $title    Site title.
  * @param array  $meta     Optional. Signup meta data. By default, contains the requested privacy setting and lang_id.
  * @return bool Whether the email notification was sent.
  */
 function wpmu_welcome_notification( $blog_id, $user_id, $password, $title, $meta = array() ) {
 	$current_network = get_network();
 
 	/**
 	 * Filters whether to bypass the welcome email sent to the site administrator after site activation.
 	 *
 	 * Returning false disables the welcome email.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param int|false $blog_id  Site ID, or false to prevent the email from sending.
 	 * @param int       $user_id  User ID of the site administrator.
 	 * @param string    $password User password, or "N/A" if the user account is not new.
 	 * @param string    $title    Site title.
 	 * @param array     $meta     Signup meta data. By default, contains the requested privacy setting and lang_id.
 	 */
 	if ( ! apply_filters( 'wpmu_welcome_notification', $blog_id, $user_id, $password, $title, $meta ) ) {
 		return false;
 	}
 
 	$user = get_userdata( $user_id );
 
 	$switched_locale = switch_to_locale( get_user_locale( $user ) );
 
 	$welcome_email = get_site_option( 'welcome_email' );
 	if ( false == $welcome_email ) {
 		/* translators: Do not translate USERNAME, SITE_NAME, BLOG_URL, PASSWORD: those are placeholders. */
 		$welcome_email = __(
 			'Howdy USERNAME,
 
 Your new SITE_NAME site has been successfully set up at:
 BLOG_URL
 
 You can log in to the administrator account with the following information:
 
 Username: USERNAME
 Password: PASSWORD
 Log in here: BLOG_URLwp-login.php
 
 We hope you enjoy your new site. Thanks!
 
 --The Team @ SITE_NAME'
 		);
 	}
 
 	$url = get_blogaddress_by_id( $blog_id );
 
 	$welcome_email = str_replace( 'SITE_NAME', $current_network->site_name, $welcome_email );
 	$welcome_email = str_replace( 'BLOG_TITLE', $title, $welcome_email );
 	$welcome_email = str_replace( 'BLOG_URL', $url, $welcome_email );
 	$welcome_email = str_replace( 'USERNAME', $user->user_login, $welcome_email );
 	$welcome_email = str_replace( 'PASSWORD', $password, $welcome_email );
 
 	/**
 	 * Filters the content of the welcome email sent to the site administrator after site activation.
 	 *
 	 * Content should be formatted for transmission via wp_mail().
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param string $welcome_email Message body of the email.
 	 * @param int    $blog_id       Site ID.
 	 * @param int    $user_id       User ID of the site administrator.
 	 * @param string $password      User password, or "N/A" if the user account is not new.
 	 * @param string $title         Site title.
 	 * @param array  $meta          Signup meta data. By default, contains the requested privacy setting and lang_id.
 	 */
 	$welcome_email = apply_filters( 'update_welcome_email', $welcome_email, $blog_id, $user_id, $password, $title, $meta );
 
 	$admin_email = get_site_option( 'admin_email' );
 
 	if ( '' === $admin_email ) {
 		$admin_email = 'support@' . wp_parse_url( network_home_url(), PHP_URL_HOST );
 	}
 
 	$from_name       = ( '' !== get_site_option( 'site_name' ) ) ? esc_html( get_site_option( 'site_name' ) ) : 'WordPress';
 	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . 'Content-Type: text/plain; charset="' . get_option( 'blog_charset' ) . "\"\n";
 	$message         = $welcome_email;
 
 	if ( empty( $current_network->site_name ) ) {
 		$current_network->site_name = 'WordPress';
 	}
 
 	/* translators: New site notification email subject. 1: Network title, 2: New site title. */
 	$subject = __( 'New %1$s Site: %2$s' );
 
 	/**
 	 * Filters the subject of the welcome email sent to the site administrator after site activation.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param string $subject Subject of the email.
 	 */
 	$subject = apply_filters( 'update_welcome_subject', sprintf( $subject, $current_network->site_name, wp_unslash( $title ) ) );
 
 	wp_mail( $user->user_email, wp_specialchars_decode( $subject ), $message, $message_headers );
 
 	if ( $switched_locale ) {
 		restore_previous_locale();
 	}
 
 	return true;
 }
 
 /**
  * Notifies the Multisite network administrator that a new site was created.
  *
  * Filter {@see 'send_new_site_email'} to disable or bypass.
  *
  * Filter {@see 'new_site_email'} to filter the contents.
  *
  * @since 5.6.0
  *
  * @param int $site_id Site ID of the new site.
  * @param int $user_id User ID of the administrator of the new site.
  * @return bool Whether the email notification was sent.
  */
 function wpmu_new_site_admin_notification( $site_id, $user_id ) {
 	$site  = get_site( $site_id );
 	$user  = get_userdata( $user_id );
 	$email = get_site_option( 'admin_email' );
 
 	if ( ! $site || ! $user || ! $email ) {
 		return false;
 	}
 
 	/**
 	 * Filters whether to send an email to the Multisite network administrator when a new site is created.
 	 *
 	 * Return false to disable sending the email.
 	 *
 	 * @since 5.6.0
 	 *
 	 * @param bool    $send Whether to send the email.
 	 * @param WP_Site $site Site object of the new site.
 	 * @param WP_User $user User object of the administrator of the new site.
 	 */
 	if ( ! apply_filters( 'send_new_site_email', true, $site, $user ) ) {
 		return false;
 	}
 
 	$switched_locale = false;
 	$network_admin   = get_user_by( 'email', $email );
 
 	if ( $network_admin ) {
 		// If the network admin email address corresponds to a user, switch to their locale.
 		$switched_locale = switch_to_locale( get_user_locale( $network_admin ) );
 	} else {
 		// Otherwise switch to the locale of the current site.
 		$switched_locale = switch_to_locale( get_locale() );
 	}
 
 	$subject = sprintf(
 		/* translators: New site notification email subject. %s: Network title. */
 		__( '[%s] New Site Created' ),
 		get_network()->site_name
 	);
 
 	$message = sprintf(
 		/* translators: New site notification email. 1: User login, 2: Site URL, 3: Site title. */
 		__(
 			'New site created by %1$s
 
 Address: %2$s
 Name: %3$s'
 		),
 		$user->user_login,
 		get_site_url( $site->id ),
 		get_blog_option( $site->id, 'blogname' )
 	);
 
 	$header = sprintf(
 		'From: "%1$s" <%2$s>',
 		_x( 'Site Admin', 'email "From" field' ),
 		$email
 	);
 
 	$new_site_email = array(
 		'to'      => $email,
 		'subject' => $subject,
 		'message' => $message,
 		'headers' => $header,
 	);
 
 	/**
 	 * Filters the content of the email sent to the Multisite network administrator when a new site is created.
 	 *
 	 * Content should be formatted for transmission via wp_mail().
 	 *
 	 * @since 5.6.0
 	 *
 	 * @param array $new_site_email {
 	 *     Used to build wp_mail().
 	 *
 	 *     @type string $to      The email address of the recipient.
 	 *     @type string $subject The subject of the email.
 	 *     @type string $message The content of the email.
 	 *     @type string $headers Headers.
 	 * }
 	 * @param WP_Site $site         Site object of the new site.
 	 * @param WP_User $user         User object of the administrator of the new site.
 	 */
 	$new_site_email = apply_filters( 'new_site_email', $new_site_email, $site, $user );
 
 	wp_mail(
 		$new_site_email['to'],
 		wp_specialchars_decode( $new_site_email['subject'] ),
 		$new_site_email['message'],
 		$new_site_email['headers']
 	);
 
 	if ( $switched_locale ) {
 		restore_previous_locale();
 	}
 
 	return true;
 }
 
 /**
  * Notify a user that their account activation has been successful.
  *
  * Filter {@see 'wpmu_welcome_user_notification'} to disable or bypass.
  *
  * Filter {@see 'update_welcome_user_email'} and {@see 'update_welcome_user_subject'} to
  * modify the content and subject line of the notification email.
  *
  * @since MU (3.0.0)
  *
  * @param int    $user_id  User ID.
  * @param string $password User password.
  * @param array  $meta     Optional. Signup meta data. Default empty array.
  * @return bool
  */
 function wpmu_welcome_user_notification( $user_id, $password, $meta = array() ) {
 	$current_network = get_network();
 
 	/**
 	 * Filters whether to bypass the welcome email after user activation.
 	 *
 	 * Returning false disables the welcome email.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param int    $user_id  User ID.
 	 * @param string $password User password.
 	 * @param array  $meta     Signup meta data. Default empty array.
 	 */
 	if ( ! apply_filters( 'wpmu_welcome_user_notification', $user_id, $password, $meta ) ) {
 		return false;
 	}
 
 	$welcome_email = get_site_option( 'welcome_user_email' );
 
 	$user = get_userdata( $user_id );
 
 	$switched_locale = switch_to_locale( get_user_locale( $user ) );
 
 	/**
 	 * Filters the content of the welcome email after user activation.
 	 *
 	 * Content should be formatted for transmission via wp_mail().
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param string $welcome_email The message body of the account activation success email.
 	 * @param int    $user_id       User ID.
 	 * @param string $password      User password.
 	 * @param array  $meta          Signup meta data. Default empty array.
 	 */
 	$welcome_email = apply_filters( 'update_welcome_user_email', $welcome_email, $user_id, $password, $meta );
 	$welcome_email = str_replace( 'SITE_NAME', $current_network->site_name, $welcome_email );
 	$welcome_email = str_replace( 'USERNAME', $user->user_login, $welcome_email );
 	$welcome_email = str_replace( 'PASSWORD', $password, $welcome_email );
 	$welcome_email = str_replace( 'LOGINLINK', wp_login_url(), $welcome_email );
 
 	$admin_email = get_site_option( 'admin_email' );
 
 	if ( '' === $admin_email ) {
 		$admin_email = 'support@' . wp_parse_url( network_home_url(), PHP_URL_HOST );
 	}
 
 	$from_name       = ( '' !== get_site_option( 'site_name' ) ) ? esc_html( get_site_option( 'site_name' ) ) : 'WordPress';
 	$message_headers = "From: \"{$from_name}\" <{$admin_email}>\n" . 'Content-Type: text/plain; charset="' . get_option( 'blog_charset' ) . "\"\n";
 	$message         = $welcome_email;
 
 	if ( empty( $current_network->site_name ) ) {
 		$current_network->site_name = 'WordPress';
 	}
 
 	/* translators: New user notification email subject. 1: Network title, 2: New user login. */
 	$subject = __( 'New %1$s User: %2$s' );
 
 	/**
 	 * Filters the subject of the welcome email after user activation.
 	 *
 	 * @since MU (3.0.0)
 	 *
 	 * @param string $subject Subject of the email.
 	 */
 	$subject = apply_filters( 'update_welcome_user_subject', sprintf( $subject, $current_network->site_name, $user->user_login ) );
 
 	wp_mail( $user->user_email, wp_specialchars_decode( $subject ), $message, $message_headers );
 
 	if ( $switched_locale ) {
 		restore_previous_locale();
 	}
 
 	return true;
 }
 
 /**
  * Get the current network.
  *
  * Returns an object containing the 'id', 'domain', 'path', and 'site_name'
  * properties of the network being viewed.
  *
  * @see wpmu_current_site()
  *
  * @since MU (3.0.0)
  *
  * @global WP_Network $current_site
  *
  * @return WP_Network
  */
 function get_current_site() {
 	global $current_site;
 	return $current_site;
 }
 
 /**
  * Get a user's most recent post.
  *
  * Walks through each of a user's blogs to find the post with
  * the most recent post_date_gmt.
  *
  * @since MU (3.0.0)
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param int $user_id
  * @return array Contains the blog_id, post_id, post_date_gmt, and post_gmt_ts
  */
 function get_most_recent_post_of_user( $user_id ) {
 	global $wpdb;
 
 	$user_blogs       = get_blogs_of_user( (int) $user_id );
 	$most_recent_post = array();
 
 	// Walk through each blog and get the most recent post
 	// published by $user_id.
 	foreach ( (array) $user_blogs as $blog ) {
 		$prefix      = $wpdb->get_blog_prefix( $blog->userblog_id );
 		$recent_post = $wpdb->get_row( $wpdb->prepare( "SELECT ID, post_date_gmt FROM {$prefix}posts WHERE post_author = %d AND post_type = 'post' AND post_status = 'publish' ORDER BY post_date_gmt DESC LIMIT 1", $user_id ), ARRAY_A );
 
 		// Make sure we found a post.
 		if ( isset( $recent_post['ID'] ) ) {
 			$post_gmt_ts = strtotime( $recent_post['post_date_gmt'] );
 
 			/*
 			 * If this is the first post checked
 			 * or if this post is newer than the current recent post,
 			 * make it the new most recent post.
 			 */
 			if ( ! isset( $most_recent_post['post_gmt_ts'] ) || ( $post_gmt_ts > $most_recent_post['post_gmt_ts'] ) ) {
 				$most_recent_post = array(
 					'blog_id'       => $blog->userblog_id,
 					'post_id'       => $recent_post['ID'],
 					'post_date_gmt' => $recent_post['post_date_gmt'],
 					'post_gmt_ts'   => $post_gmt_ts,
 				);
 			}
 		}
 	}
 
 	return $most_recent_post;
 }
 
 //
 // Misc functions.
 //
 
 /**
  * Check an array of MIME types against a list of allowed types.
  *
  * WordPress ships with a set of allowed upload filetypes,
  * which is defined in wp-includes/functions.php in
  * get_allowed_mime_types(). This function is used to filter
  * that list against the filetypes allowed provided by Multisite
  * Super Admins at wp-admin/network/settings.php.
  *
  * @since MU (3.0.0)
  *
  * @param array $mimes
  * @return array
  */
 function check_upload_mimes( $mimes ) {
 	$site_exts  = explode( ' ', get_site_option( 'upload_filetypes', 'jpg jpeg png gif' ) );
 	$site_mimes = array();
 	foreach ( $site_exts as $ext ) {
 		foreach ( $mimes as $ext_pattern => $mime ) {
 			if ( '' !== $ext && false !== strpos( $ext_pattern, $ext ) ) {
 				$site_mimes[ $ext_pattern ] = $mime;
 			}
 		}
 	}
 	return $site_mimes;
 }
 
 /**
  * Update a blog's post count.
  *
  * WordPress MS stores a blog's post count as an option so as
  * to avoid extraneous COUNTs when a blog's details are fetched
  * with get_site(). This function is called when posts are published
  * or unpublished to make sure the count stays current.
  *
  * @since MU (3.0.0)
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param string $deprecated Not used.
  */
 function update_posts_count( $deprecated = '' ) {
 	global $wpdb;
 	update_option( 'post_count', (int) $wpdb->get_var( "SELECT COUNT(ID) FROM {$wpdb->posts} WHERE post_status = 'publish' and post_type = 'post'" ) );
 }
 
 /**
  * Logs the user email, IP, and registration date of a new site.
  *
  * @since MU (3.0.0)
  * @since 5.1.0 Parameters now support input from the {@see 'wp_initialize_site'} action.
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param WP_Site|int $blog_id The new site's object or ID.
  * @param int|array   $user_id User ID, or array of arguments including 'user_id'.
  */
 function wpmu_log_new_registrations( $blog_id, $user_id ) {
 	global $wpdb;
 
 	if ( is_object( $blog_id ) ) {
 		$blog_id = $blog_id->blog_id;
 	}
 
 	if ( is_array( $user_id ) ) {
 		$user_id = ! empty( $user_id['user_id'] ) ? $user_id['user_id'] : 0;
 	}
 
 	$user = get_userdata( (int) $user_id );
 	if ( $user ) {
 		$wpdb->insert(
 			$wpdb->registration_log,
 			array(
 				'email'           => $user->user_email,
 				'IP'              => preg_replace( '/[^0-9., ]/', '', wp_unslash( $_SERVER['REMOTE_ADDR'] ) ),
 				'blog_id'         => $blog_id,
 				'date_registered' => current_time( 'mysql' ),
 			)
 		);
 	}
 }
 
 /**
  * Maintains a canonical list of terms by syncing terms created for each blog with the global terms table.
  *
  * @since 3.0.0
  *
  * @see term_id_filter
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param int    $term_id    An ID for a term on the current blog.
  * @param string $deprecated Not used.
  * @return int An ID from the global terms table mapped from $term_id.
  */
 function global_terms( $term_id, $deprecated = '' ) {
 	global $wpdb;
 	static $global_terms_recurse = null;
 
 	if ( ! global_terms_enabled() ) {
 		return $term_id;
 	}
 
 	// Prevent a race condition.
 	$recurse_start = false;
 	if ( null === $global_terms_recurse ) {
 		$recurse_start        = true;
 		$global_terms_recurse = 1;
 	} elseif ( 10 < $global_terms_recurse++ ) {
 		return $term_id;
 	}
 
 	$term_id = (int) $term_id;
 	$c       = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->terms WHERE term_id = %d", $term_id ) );
 
 	$global_id = $wpdb->get_var( $wpdb->prepare( "SELECT cat_ID FROM $wpdb->sitecategories WHERE category_nicename = %s", $c->slug ) );
 	if ( null == $global_id ) {
 		$used_global_id = $wpdb->get_var( $wpdb->prepare( "SELECT cat_ID FROM $wpdb->sitecategories WHERE cat_ID = %d", $c->term_id ) );
 		if ( null == $used_global_id ) {
 			$wpdb->insert(
 				$wpdb->sitecategories,
 				array(
 					'cat_ID'            => $term_id,
 					'cat_name'          => $c->name,
 					'category_nicename' => $c->slug,
 				)
 			);
 			$global_id = $wpdb->insert_id;
 			if ( empty( $global_id ) ) {
 				return $term_id;
 			}
 		} else {
 			$max_global_id = $wpdb->get_var( "SELECT MAX(cat_ID) FROM $wpdb->sitecategories" );
 			$max_local_id  = $wpdb->get_var( "SELECT MAX(term_id) FROM $wpdb->terms" );
 			$new_global_id = max( $max_global_id, $max_local_id ) + mt_rand( 100, 400 );
 			$wpdb->insert(
 				$wpdb->sitecategories,
 				array(
 					'cat_ID'            => $new_global_id,
 					'cat_name'          => $c->name,
 					'category_nicename' => $c->slug,
 				)
 			);
 			$global_id = $wpdb->insert_id;
 		}
 	} elseif ( $global_id != $term_id ) {
 		$local_id = $wpdb->get_var( $wpdb->prepare( "SELECT term_id FROM $wpdb->terms WHERE term_id = %d", $global_id ) );
 		if ( null != $local_id ) {
 			global_terms( $local_id );
 			if ( 10 < $global_terms_recurse ) {
 				$global_id = $term_id;
 			}
 		}
 	}
 
 	if ( $global_id != $term_id ) {
 		if ( get_option( 'default_category' ) == $term_id ) {
 			update_option( 'default_category', $global_id );
 		}
 
 		$wpdb->update( $wpdb->terms, array( 'term_id' => $global_id ), array( 'term_id' => $term_id ) );
 		$wpdb->update( $wpdb->term_taxonomy, array( 'term_id' => $global_id ), array( 'term_id' => $term_id ) );
 		$wpdb->update( $wpdb->term_taxonomy, array( 'parent' => $global_id ), array( 'parent' => $term_id ) );
 
 		clean_term_cache( $term_id );
 	}
 	if ( $recurse_start ) {
 		$global_terms_recurse = null;
 	}
 
 	return $global_id;
 }
 
 /**
  * Ensure that the current site's domain is listed in the allowed redirect host list.
  *
  * @see wp_validate_redirect()
  * @since MU (3.0.0)
  *
  * @param array|string $deprecated Not used.
  * @return string[] {
  *     An array containing the current site's domain.
  *
  *     @type string $0 The current site's domain.
  * }
  */
 function redirect_this_site( $deprecated = '' ) {
 	return array( get_network()->domain );
 }
 
 /**
  * Check whether an upload is too big.
  *
  * @since MU (3.0.0)
  *
  * @blessed
  *
  * @param array $upload
  * @return string|array If the upload is under the size limit, $upload is returned. Otherwise returns an error message.
  */
 function upload_is_file_too_big( $upload ) {
 	if ( ! is_array( $upload ) || defined( 'WP_IMPORTING' ) || get_site_option( 'upload_space_check_disabled' ) ) {
 		return $upload;
 	}
 
 	if ( strlen( $upload['bits'] ) > ( KB_IN_BYTES * get_site_option( 'fileupload_maxk', 1500 ) ) ) {
 		/* translators: %s: Maximum allowed file size in kilobytes. */
 		return sprintf( __( 'This file is too big. Files must be less than %s KB in size.' ) . '<br />', get_site_option( 'fileupload_maxk', 1500 ) );
 	}
 
 	return $upload;
 }
 
 /**
  * Add a nonce field to the signup page.
  *
  * @since MU (3.0.0)
  */
 function signup_nonce_fields() {
 	$id = mt_rand();
 	echo "<input type='hidden' name='signup_form_id' value='{$id}' />";
 	wp_nonce_field( 'signup_form_' . $id, '_signup_form', false );
 }
 
 /**
  * Process the signup nonce created in signup_nonce_fields().
  *
  * @since MU (3.0.0)
  *
  * @param array $result
  * @return array
  */
 function signup_nonce_check( $result ) {
 	if ( ! strpos( $_SERVER['PHP_SELF'], 'wp-signup.php' ) ) {
 		return $result;
 	}
 
 	if ( ! wp_verify_nonce( $_POST['_signup_form'], 'signup_form_' . $_POST['signup_form_id'] ) ) {
 		$result['errors']->add( 'invalid_nonce', __( 'Unable to submit this form, please try again.' ) );
 	}
 
 	return $result;
 }
 
 /**
  * Correct 404 redirects when NOBLOGREDIRECT is defined.
  *
  * @since MU (3.0.0)
  */
 function maybe_redirect_404() {
 	if ( is_main_site() && is_404() && defined( 'NOBLOGREDIRECT' ) ) {
 		/**
 		 * Filters the redirect URL for 404s on the main site.
 		 *
 		 * The filter is only evaluated if the NOBLOGREDIRECT constant is defined.
 		 *
 		 * @since 3.0.0
 		 *
 		 * @param string $no_blog_redirect The redirect URL defined in NOBLOGREDIRECT.
 		 */
 		$destination = apply_filters( 'blog_redirect_404', NOBLOGREDIRECT );
 
 		if ( $destination ) {
 			if ( '%siteurl%' === $destination ) {
 				$destination = network_home_url();
 			}
 
 			wp_redirect( $destination );
 			exit;
 		}
 	}
 }
 
 /**
  * Add a new user to a blog by visiting /newbloguser/{key}/.
  *
  * This will only work when the user's details are saved as an option
  * keyed as 'new_user_{key}', where '{key}' is a hash generated for the user to be
  * added, as when a user is invited through the regular WP Add User interface.
  *
  * @since MU (3.0.0)
  */
 function maybe_add_existing_user_to_blog() {
 	if ( false === strpos( $_SERVER['REQUEST_URI'], '/newbloguser/' ) ) {
 		return;
 	}
 
 	$parts = explode( '/', $_SERVER['REQUEST_URI'] );
 	$key   = array_pop( $parts );
 
 	if ( '' === $key ) {
 		$key = array_pop( $parts );
 	}
 
 	$details = get_option( 'new_user_' . $key );
 	if ( ! empty( $details ) ) {
 		delete_option( 'new_user_' . $key );
 	}
 
 	if ( empty( $details ) || is_wp_error( add_existing_user_to_blog( $details ) ) ) {
 		wp_die(
 			sprintf(
 				/* translators: %s: Home URL. */
 				__( 'An error occurred adding you to this site. Go to the <a href="%s">homepage</a>.' ),
 				home_url()
 			)
 		);
 	}
 
 	wp_die(
 		sprintf(
 			/* translators: 1: Home URL, 2: Admin URL. */
 			__( 'You have been added to this site. Please visit the <a href="%1$s">homepage</a> or <a href="%2$s">log in</a> using your username and password.' ),
 			home_url(),
 			admin_url()
 		),
 		__( 'WordPress &rsaquo; Success' ),
 		array( 'response' => 200 )
 	);
 }
 
 /**
  * Add a user to a blog based on details from maybe_add_existing_user_to_blog().
  *
  * @since MU (3.0.0)
  *
  * @param array|false $details {
  *     User details. Must at least contain values for the keys listed below.
  *
  *     @type int    $user_id The ID of the user being added to the current blog.
  *     @type string $role    The role to be assigned to the user.
  * }
  * @return true|WP_Error|void True on success or a WP_Error object if the user doesn't exist
  *                            or could not be added. Void if $details array was not provided.
  */
 function add_existing_user_to_blog( $details = false ) {
 	if ( is_array( $details ) ) {
 		$blog_id = get_current_blog_id();
 		$result  = add_user_to_blog( $blog_id, $details['user_id'], $details['role'] );
 
 		/**
 		 * Fires immediately after an existing user is added to a site.
 		 *
 		 * @since MU (3.0.0)
 		 *
 		 * @param int           $user_id User ID.
 		 * @param true|WP_Error $result  True on success or a WP_Error object if the user doesn't exist
 		 *                               or could not be added.
 		 */
 		do_action( 'added_existing_user', $details['user_id'], $result );
 
 		return $result;
 	}
 }
 
 /**
  * Adds a newly created user to the appropriate blog
  *
  * To add a user in general, use add_user_to_blog(). This function
  * is specifically hooked into the {@see 'wpmu_activate_user'} action.
  *
  * @since MU (3.0.0)
  *
  * @see add_user_to_blog()
  *
  * @param int    $user_id  User ID.
  * @param string $password User password. Ignored.
  * @param array  $meta     Signup meta data.
  */
 function add_new_user_to_blog( $user_id, $password, $meta ) {
 	if ( ! empty( $meta['add_to_blog'] ) ) {
 		$blog_id = $meta['add_to_blog'];
 		$role    = $meta['new_role'];
 		remove_user_from_blog( $user_id, get_network()->site_id ); // Remove user from main blog.
 
 		$result = add_user_to_blog( $blog_id, $user_id, $role );
 
 		if ( ! is_wp_error( $result ) ) {
 			update_user_meta( $user_id, 'primary_blog', $blog_id );
 		}
 	}
 }
 
 /**
  * Correct From host on outgoing mail to match the site domain
  *
  * @since MU (3.0.0)
  *
  * @param PHPMailer $phpmailer The PHPMailer instance (passed by reference).
  */
 function fix_phpmailer_messageid( $phpmailer ) {
 	$phpmailer->Hostname = get_network()->domain;
 }
 
 /**
  * Check to see whether a user is marked as a spammer, based on user login.
  *
  * @since MU (3.0.0)
  *
  * @param string|WP_User $user Optional. Defaults to current user. WP_User object,
  *                             or user login name as a string.
  * @return bool
  */
 function is_user_spammy( $user = null ) {
 	if ( ! ( $user instanceof WP_User ) ) {
 		if ( $user ) {
 			$user = get_user_by( 'login', $user );
 		} else {
 			$user = wp_get_current_user();
 		}
 	}
 
 	return $user && isset( $user->spam ) && 1 == $user->spam;
 }
 
 /**
  * Update this blog's 'public' setting in the global blogs table.
  *
  * Public blogs have a setting of 1, private blogs are 0.
  *
  * @since MU (3.0.0)
  *
  * @param int $old_value
  * @param int $value     The new public value
  */
 function update_blog_public( $old_value, $value ) {
 	update_blog_status( get_current_blog_id(), 'public', (int) $value );
 }
 
 /**
  * Check whether users can self-register, based on Network settings.
  *
  * @since MU (3.0.0)
  *
  * @return bool
  */
 function users_can_register_signup_filter() {
 	$registration = get_site_option( 'registration' );
 	return ( 'all' === $registration || 'user' === $registration );
 }
 
 /**
  * Ensure that the welcome message is not empty. Currently unused.
  *
  * @since MU (3.0.0)
  *
  * @param string $text
  * @return string
  */
 function welcome_user_msg_filter( $text ) {
 	if ( ! $text ) {
 		remove_filter( 'site_option_welcome_user_email', 'welcome_user_msg_filter' );
 
 		/* translators: Do not translate USERNAME, PASSWORD, LOGINLINK, SITE_NAME: those are placeholders. */
 		$text = __(
 			'Howdy USERNAME,
 
 Your new account is set up.
 
 You can log in with the following information:
 Username: USERNAME
 Password: PASSWORD
 LOGINLINK
 
 Thanks!
 
 --The Team @ SITE_NAME'
 		);
 		update_site_option( 'welcome_user_email', $text );
 	}
 	return $text;
 }
 
 /**
  * Whether to force SSL on content.
  *
  * @since 2.8.5
  *
  * @param bool $force
  * @return bool True if forced, false if not forced.
  */
 function force_ssl_content( $force = '' ) {
 	static $forced_content = false;
 
 	if ( ! $force ) {
 		$old_forced     = $forced_content;
 		$forced_content = $force;
 		return $old_forced;
 	}
 
 	return $forced_content;
 }
 
 /**
  * Formats a URL to use https.
  *
  * Useful as a filter.
  *
  * @since 2.8.5
  *
  * @param string $url URL
  * @return string URL with https as the scheme
  */
 function filter_SSL( $url ) {  // phpcs:ignore WordPress.NamingConventions.ValidFunctionName.FunctionNameInvalid
 	if ( ! is_string( $url ) ) {
 		return get_bloginfo( 'url' ); // Return home blog URL with proper scheme.
 	}
 
 	if ( force_ssl_content() && is_ssl() ) {
 		$url = set_url_scheme( $url, 'https' );
 	}
 
 	return $url;
 }
 
 /**
  * Schedule update of the network-wide counts for the current network.
  *
  * @since 3.1.0
  */
 function wp_schedule_update_network_counts() {
 	if ( ! is_main_site() ) {
 		return;
 	}
 
 	if ( ! wp_next_scheduled( 'update_network_counts' ) && ! wp_installing() ) {
 		wp_schedule_event( time(), 'twicedaily', 'update_network_counts' );
 	}
 }
 
 /**
  * Update the network-wide counts for the current network.
  *
  * @since 3.1.0
  * @since 4.8.0 The `$network_id` parameter has been added.
  *
  * @param int|null $network_id ID of the network. Default is the current network.
  */
 function wp_update_network_counts( $network_id = null ) {
 	wp_update_network_user_counts( $network_id );
 	wp_update_network_site_counts( $network_id );
 }
 
 /**
  * Update the count of sites for the current network.
  *
  * If enabled through the {@see 'enable_live_network_counts'} filter, update the sites count
  * on a network when a site is created or its status is updated.
  *
  * @since 3.7.0
  * @since 4.8.0 The `$network_id` parameter has been added.
  *
  * @param int|null $network_id ID of the network. Default is the current network.
  */
 function wp_maybe_update_network_site_counts( $network_id = null ) {
 	$is_small_network = ! wp_is_large_network( 'sites', $network_id );
 
 	/**
 	 * Filters whether to update network site or user counts when a new site is created.
 	 *
 	 * @since 3.7.0
 	 *
 	 * @see wp_is_large_network()
 	 *
 	 * @param bool   $small_network Whether the network is considered small.
 	 * @param string $context       Context. Either 'users' or 'sites'.
 	 */
 	if ( ! apply_filters( 'enable_live_network_counts', $is_small_network, 'sites' ) ) {
 		return;
 	}
 
 	wp_update_network_site_counts( $network_id );
 }
 
 /**
  * Update the network-wide users count.
  *
  * If enabled through the {@see 'enable_live_network_counts'} filter, update the users count
  * on a network when a user is created or its status is updated.
  *
  * @since 3.7.0
  * @since 4.8.0 The `$network_id` parameter has been added.
  *
  * @param int|null $network_id ID of the network. Default is the current network.
  */
 function wp_maybe_update_network_user_counts( $network_id = null ) {
 	$is_small_network = ! wp_is_large_network( 'users', $network_id );
 
 	/** This filter is documented in wp-includes/ms-functions.php */
 	if ( ! apply_filters( 'enable_live_network_counts', $is_small_network, 'users' ) ) {
 		return;
 	}
 
 	wp_update_network_user_counts( $network_id );
 }
 
 /**
  * Update the network-wide site count.
  *
  * @since 3.7.0
  * @since 4.8.0 The `$network_id` parameter has been added.
  *
  * @param int|null $network_id ID of the network. Default is the current network.
  */
 function wp_update_network_site_counts( $network_id = null ) {
 	$network_id = (int) $network_id;
 	if ( ! $network_id ) {
 		$network_id = get_current_network_id();
 	}
 
 	$count = get_sites(
 		array(
 			'network_id'             => $network_id,
 			'spam'                   => 0,
 			'deleted'                => 0,
 			'archived'               => 0,
 			'count'                  => true,
 			'update_site_meta_cache' => false,
 		)
 	);
 
 	update_network_option( $network_id, 'blog_count', $count );
 }
 
 /**
  * Update the network-wide user count.
  *
  * @since 3.7.0
  * @since 4.8.0 The `$network_id` parameter has been added.
  *
  * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param int|null $network_id ID of the network. Default is the current network.
  */
 function wp_update_network_user_counts( $network_id = null ) {
 	global $wpdb;
 
 	$count = $wpdb->get_var( "SELECT COUNT(ID) as c FROM $wpdb->users WHERE spam = '0' AND deleted = '0'" );
 	update_network_option( $network_id, 'user_count', $count );
 }
 
 /**
  * Returns the space used by the current site.
  *
  * @since 3.5.0
  *
  * @return int Used space in megabytes.
  */
 function get_space_used() {
 	/**
 	 * Filters the amount of storage space used by the current site, in megabytes.
 	 *
 	 * @since 3.5.0
 	 *
 	 * @param int|false $space_used The amount of used space, in megabytes. Default false.
 	 */
 	$space_used = apply_filters( 'pre_get_space_used', false );
 
 	if ( false === $space_used ) {
 		$upload_dir = wp_upload_dir();
 		$space_used = get_dirsize( $upload_dir['basedir'] ) / MB_IN_BYTES;
 	}
 
 	return $space_used;
 }
 
 /**
  * Returns the upload quota for the current blog.
  *
  * @since MU (3.0.0)
  *
  * @return int Quota in megabytes
  */
 function get_space_allowed() {
 	$space_allowed = get_option( 'blog_upload_space' );
 
 	if ( ! is_numeric( $space_allowed ) ) {
 		$space_allowed = get_site_option( 'blog_upload_space' );
 	}
 
 	if ( ! is_numeric( $space_allowed ) ) {
 		$space_allowed = 100;
 	}
 
 	/**
 	 * Filters the upload quota for the current site.
 	 *
 	 * @since 3.7.0
 	 *
 	 * @param int $space_allowed Upload quota in megabytes for the current blog.
 	 */
 	return apply_filters( 'get_space_allowed', $space_allowed );
 }
 
 /**
  * Determines if there is any upload space left in the current blog's quota.
  *
  * @since 3.0.0
  *
  * @return int of upload space available in bytes
  */
 function get_upload_space_available() {
 	$allowed = get_space_allowed();
 	if ( $allowed < 0 ) {
 		$allowed = 0;
 	}
 	$space_allowed = $allowed * MB_IN_BYTES;
 	if ( get_site_option( 'upload_space_check_disabled' ) ) {
 		return $space_allowed;
 	}
 
 	$space_used = get_space_used() * MB_IN_BYTES;
 
 	if ( ( $space_allowed - $space_used ) <= 0 ) {
 		return 0;
 	}
 
 	return $space_allowed - $space_used;
 }
 
 /**
  * Determines if there is any upload space left in the current blog's quota.
  *
  * @since 3.0.0
  * @return bool True if space is available, false otherwise.
  */
 function is_upload_space_available() {
 	if ( get_site_option( 'upload_space_check_disabled' ) ) {
 		return true;
 	}
 
 	return (bool) get_upload_space_available();
 }
 
 /**
  * Filters the maximum upload file size allowed, in bytes.
  *
  * @since 3.0.0
  *
  * @param int $size Upload size limit in bytes.
  * @return int Upload size limit in bytes.
  */
 function upload_size_limit_filter( $size ) {
 	$fileupload_maxk = KB_IN_BYTES * get_site_option( 'fileupload_maxk', 1500 );
 	if ( get_site_option( 'upload_space_check_disabled' ) ) {
 		return min( $size, $fileupload_maxk );
 	}
 
 	return min( $size, $fileupload_maxk, get_upload_space_available() );
 }
 
 /**
  * Whether or not we have a large network.
  *
  * The default criteria for a large network is either more than 10,000 users or more than 10,000 sites.
  * Plugins can alter this criteria using the {@see 'wp_is_large_network'} filter.
  *
  * @since 3.3.0
  * @since 4.8.0 The `$network_id` parameter has been added.
  *
  * @param string   $using      'sites or 'users'. Default is 'sites'.
  * @param int|null $network_id ID of the network. Default is the current network.
  * @return bool True if the network meets the criteria for large. False otherwise.
  */
 function wp_is_large_network( $using = 'sites', $network_id = null ) {
 	$network_id = (int) $network_id;
 	if ( ! $network_id ) {
 		$network_id = get_current_network_id();
 	}
 
 	if ( 'users' === $using ) {
 		$count = get_user_count( $network_id );
 		/**
 		 * Filters whether the network is considered large.
 		 *
 		 * @since 3.3.0
 		 * @since 4.8.0 The `$network_id` parameter has been added.
 		 *
 		 * @param bool   $is_large_network Whether the network has more than 10000 users or sites.
 		 * @param string $component        The component to count. Accepts 'users', or 'sites'.
 		 * @param int    $count            The count of items for the component.
 		 * @param int    $network_id       The ID of the network being checked.
 		 */
 		return apply_filters( 'wp_is_large_network', $count > 10000, 'users', $count, $network_id );
 	}
 
 	$count = get_blog_count( $network_id );
 
 	/** This filter is documented in wp-includes/ms-functions.php */
 	return apply_filters( 'wp_is_large_network', $count > 10000, 'sites', $count, $network_id );
 }
 
 /**
  * Retrieves a list of reserved site on a sub-directory Multisite installation.
  *
  * @since 4.4.0
  *
  * @return string[] Array of reserved names.
  */
 function get_subdirectory_reserved_names() {
 	$names = array(
 		'page',
 		'comments',
 		'blog',
 		'files',
 		'feed',
 		'wp-admin',
 		'wp-content',
 		'wp-includes',
 		'wp-json',
 		'embed',
 	);
 
 	/**
 	 * Filters reserved site names on a sub-directory Multisite installation.
 	 *
 	 * @since 3.0.0
 	 * @since 4.4.0 'wp-admin', 'wp-content', 'wp-includes', 'wp-json', and 'embed' were added
 	 *              to the reserved names list.
 	 *
 	 * @param string[] $subdirectory_reserved_names Array of reserved names.
 	 */
 	return apply_filters( 'subdirectory_reserved_names', $names );
 }
 
 /**
  * Send a confirmation request email when a change of network admin email address is attempted.
  *
  * The new network admin address will not become active until confirmed.
  *
  * @since 4.9.0
  *
  * @param string $old_value The old network admin email address.
  * @param string $value     The proposed new network admin email address.
  */
 function update_network_option_new_admin_email( $old_value, $value ) {
 	if ( get_site_option( 'admin_email' ) === $value || ! is_email( $value ) ) {
 		return;
 	}
 
 	$hash            = md5( $value . time() . mt_rand() );
 	$new_admin_email = array(
 		'hash'     => $hash,
 		'newemail' => $value,
 	);
 	update_site_option( 'network_admin_hash', $new_admin_email );
 
 	$switched_locale = switch_to_locale( get_user_locale() );
 
 	/* translators: Do not translate USERNAME, ADMIN_URL, EMAIL, SITENAME, SITEURL: those are placeholders. */
 	$email_text = __(
 		'Howdy ###USERNAME###,
 
 You recently requested to have the network admin email address on
 your network changed.
 
 If this is correct, please click on the following link to change it:
 ###ADMIN_URL###
 
 You can safely ignore and delete this email if you do not want to
 take this action.
 
 This email has been sent to ###EMAIL###
 
 Regards,
 All at ###SITENAME###
 ###SITEURL###'
 	);
 
 	/**
 	 * Filters the text of the email sent when a change of network admin email address is attempted.
 	 *
 	 * The following strings have a special meaning and will get replaced dynamically:
 	 * ###USERNAME###  The current user's username.
 	 * ###ADMIN_URL### The link to click on to confirm the email change.
 	 * ###EMAIL###     The proposed new network admin email address.
 	 * ###SITENAME###  The name of the network.
 	 * ###SITEURL###   The URL to the network.
 	 *
 	 * @since 4.9.0
 	 *
 	 * @param string $email_text      Text in the email.
 	 * @param array  $new_admin_email {
 	 *     Data relating to the new network admin email address.
 	 *
 	 *     @type string $hash     The secure hash used in the confirmation link URL.
 	 *     @type string $newemail The proposed new network admin email address.
 	 * }
 	 */
 	$content = apply_filters( 'new_network_admin_email_content', $email_text, $new_admin_email );
 
 	$current_user = wp_get_current_user();
 	$content      = str_replace( '###USERNAME###', $current_user->user_login, $content );
 	$content      = str_replace( '###ADMIN_URL###', esc_url( network_admin_url( 'settings.php?network_admin_hash=' . $hash ) ), $content );
 	$content      = str_replace( '###EMAIL###', $value, $content );
 	$content      = str_replace( '###SITENAME###', wp_specialchars_decode( get_site_option( 'site_name' ), ENT_QUOTES ), $content );
 	$content      = str_replace( '###SITEURL###', network_home_url(), $content );
 
 	wp_mail(
 		$value,
 		sprintf(
 			/* translators: Email change notification email subject. %s: Network title. */
 			__( '[%s] Network Admin Email Change Request' ),
 			wp_specialchars_decode( get_site_option( 'site_name' ), ENT_QUOTES )
 		),
 		$content
 	);
 
 	if ( $switched_locale ) {
 		restore_previous_locale();
 	}
 }
 
 /**
  * Send an email to the old network admin email address when the network admin email address changes.
  *
  * @since 4.9.0
  *
  * @param string $option_name The relevant database option name.
  * @param string $new_email   The new network admin email address.
  * @param string $old_email   The old network admin email address.
  * @param int    $network_id  ID of the network.
  */
 function wp_network_admin_email_change_notification( $option_name, $new_email, $old_email, $network_id ) {
 	$send = true;
 
 	// Don't send the notification to the default 'admin_email' value.
 	if ( 'you@example.com' === $old_email ) {
 		$send = false;
 	}
 
 	/**
 	 * Filters whether to send the network admin email change notification email.
 	 *
 	 * @since 4.9.0
 	 *
 	 * @param bool   $send       Whether to send the email notification.
 	 * @param string $old_email  The old network admin email address.
 	 * @param string $new_email  The new network admin email address.
 	 * @param int    $network_id ID of the network.
 	 */
 	$send = apply_filters( 'send_network_admin_email_change_email', $send, $old_email, $new_email, $network_id );
 
 	if ( ! $send ) {
 		return;
 	}
 
 	/* translators: Do not translate OLD_EMAIL, NEW_EMAIL, SITENAME, SITEURL: those are placeholders. */
 	$email_change_text = __(
 		'Hi,
 
 This notice confirms that the network admin email address was changed on ###SITENAME###.
 
 The new network admin email address is ###NEW_EMAIL###.
 
 This email has been sent to ###OLD_EMAIL###
 
 Regards,
 All at ###SITENAME###
 ###SITEURL###'
 	);
 
 	$email_change_email = array(
 		'to'      => $old_email,
 		/* translators: Network admin email change notification email subject. %s: Network title. */
 		'subject' => __( '[%s] Network Admin Email Changed' ),
 		'message' => $email_change_text,
 		'headers' => '',
 	);
 	// Get network name.
 	$network_name = wp_specialchars_decode( get_site_option( 'site_name' ), ENT_QUOTES );
 
 	/**
 	 * Filters the contents of the email notification sent when the network admin email address is changed.
 	 *
 	 * @since 4.9.0
 	 *
 	 * @param array $email_change_email {
 	 *     Used to build wp_mail().
 	 *
 	 *     @type string $to      The intended recipient.
 	 *     @type string $subject The subject of the email.
 	 *     @type string $message The content of the email.
 	 *         The following strings have a special meaning and will get replaced dynamically:
 	 *         - ###OLD_EMAIL### The old network admin email address.
 	 *         - ###NEW_EMAIL### The new network admin email address.
 	 *         - ###SITENAME###  The name of the network.
 	 *         - ###SITEURL###   The URL to the site.
 	 *     @type string $headers Headers.
 	 * }
 	 * @param string $old_email  The old network admin email address.
 	 * @param string $new_email  The new network admin email address.
 	 * @param int    $network_id ID of the network.
 	 */
 	$email_change_email = apply_filters( 'network_admin_email_change_email', $email_change_email, $old_email, $new_email, $network_id );
 
 	$email_change_email['message'] = str_replace( '###OLD_EMAIL###', $old_email, $email_change_email['message'] );
 	$email_change_email['message'] = str_replace( '###NEW_EMAIL###', $new_email, $email_change_email['message'] );
 	$email_change_email['message'] = str_replace( '###SITENAME###', $network_name, $email_change_email['message'] );
 	$email_change_email['message'] = str_replace( '###SITEURL###', home_url(), $email_change_email['message'] );
 
 	wp_mail(
 		$email_change_email['to'],
 		sprintf(
 			$email_change_email['subject'],
 			$network_name
 		),
 		$email_change_email['message'],
 		$email_change_email['headers']
 	);
 }