• File: ms-functions-20260727063025.php
  • Full Path: /home/u505525515/domains/medineeestates.com/public_html/wp-includes/ms-functions-20260727063025.php
  • Date Modified: 05/25/2026 6:29 AM
  • File size: 89.69 KB
  • MIME-type: text/x-php
  • Charset: utf-8
<?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;
}

/**
 * Gets 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 ) {
            $current_network_id = get_current_network_id();

            foreach ( (array) $blogs as $blog_id => $blog ) {
                if ( $blog->site_id !== $current_network_id ) {
                    continue;
                }

                $details = get_site( $blog_id );
                if ( is_object( $details )
                    && '0' === $details->archived && '0' === $details->spam && '0' === $details->deleted
                ) {
                    $ret = $details;
                    if ( (int) 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;
    }
}

/**
 * Gets the number of active sites on the 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    User role.
 * @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;
}

/**
 * Removes 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;

    $user_id = (int) $user_id;
    $blog_id = (int) $blog_id;

    switch_to_blog( $blog_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 = (int) 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 );
    }

    $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' );
        }
    }

    clean_user_cache( $user_id );
    restore_current_blog();

    return true;
}

/**
 * Gets 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;
}

/**
 * Gets 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 Website domain.
 * @param string $path   Optional. Not required for subdomain installations. Default '/'.
 * @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;
            }

            if ( str_ends_with( $normalized_email, ".$banned_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 );
}

/**
 * Sanitizes and validates 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. There are problems with them blocking some emails from WordPress. 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 );
        $email_domain          = strtolower( substr( $user_email, 1 + strpos( $user_email, '@' ) ) );

        if ( ! in_array( $email_domain, $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',
            sprintf(
                /* translators: %s: Link to the login page. */
                __( '<strong>Error:</strong> This email address is already registered. <a href="%s">Log in</a> with this address or choose another one.' ),
                wp_login_url()
            )
        );
    }

    // 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 is pending activation and is not available for new registration. If you made a previous attempt with this email address, please check your inbox for an activation email. If left unconfirmed, it will become available in a couple of days.' ) );
        }
    }

    $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 site name provided by the user. Must be unique.
 * @param string         $blog_title The site title provided by the user.
 * @param WP_User|string $user       Optional. The user object to check against the new site name.
 *                                   Default empty string.
 * @return array {
 *     Array of domain, path, site name, site 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 ( ! is_array( $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 site 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!' ) );
    }

    /*
     * Do not allow users to create a site that matches an existing user's login name,
     * unless it's the user's own username.
     */
    if ( username_exists( $blogname ) ) {
        if ( ! $user instanceof WP_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, site name, site 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 Site 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 );
}

/**
 * Records 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 );
}

/**
 * Records 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 );
}

/**
 * Sends 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,
    #[\SensitiveParameter]
    $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 = $user && switch_to_user_locale( $user->ID );

    $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 site, 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;
}

/**
 * Sends 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,
    #[\SensitiveParameter]
    $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 = $user && switch_to_user_locale( $user->ID );

    // 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;
}

/**
 * Activates 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(
    #[\SensitiveParameter]
    $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 string $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 an associated signup entry when a user is deleted from the database.
 *
 * @since 5.5.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @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 ) );
}

/**
 * Creates 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,
    #[\SensitiveParameter]
    $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;
}

/**
 * Creates 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.
 *                           Default 1.
 * @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_sites_last_changed();

    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 ) ) {
        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|string $blog_id The new site's ID as an integer or numeric string.
     */
    $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 ) ) {
        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. Only relevant on multi-network installations.
 *                           Default 1.
 * @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. Only relevant 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,
    #[\SensitiveParameter]
    $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_user_locale( $user_id );

    $welcome_email = get_site_option( 'welcome_email' );

    if ( ! $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_user_locale( $network_admin->ID );
    } 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;
}

/**
 * Notifies 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,
    #[\SensitiveParameter]
    $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_user_locale( $user_id );

    /**
     * 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;
}

/**
 * Gets 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 The current network.
 *
 * @return WP_Network The current network.
 */
function get_current_site() {
    global $current_site;
    return $current_site;
}

/**
 * Gets 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 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.
//

/**
 * Checks 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 && str_contains( $ext_pattern, $ext ) ) {
                $site_mimes[ $ext_pattern ] = $mime;
            }
        }
    }
    return $site_mimes;
}

/**
 * Updates 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'" ), true );
}

/**
 * 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' ),
            )
        );
    }
}

/**
 * Ensures 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 );
}

/**
 * Checks whether an upload is too big.
 *
 * @since MU (3.0.0)
 *
 * @param array $upload An array of information about the newly-uploaded file.
 * @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;
}

/**
 * Adds 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 );
}

/**
 * Processes 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;
}

/**
 * Corrects 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;
        }
    }
}

/**
 * Adds 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 ( ! str_contains( $_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 )
    );
}

/**
 * Adds 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,
    #[\SensitiveParameter]
    $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 );
        }
    }
}

/**
 * Corrects From host on outgoing mail to match the site domain.
 *
 * @since MU (3.0.0)
 *
 * @param PHPMailer\PHPMailer\PHPMailer $phpmailer The PHPMailer instance (passed by reference).
 */
function fix_phpmailer_messageid( $phpmailer ) {
    $phpmailer->Hostname = get_network()->domain;
}

/**
 * Determines 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;
}

/**
 * Updates 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 The old public 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 );
}

/**
 * Determines 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 );
}

/**
 * Ensures 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;
}

/**
 * Determines whether to force SSL on content.
 *
 * @since 2.8.5
 *
 * @param bool|null $force Optional. Whether to force SSL in admin screens. Default null.
 * @return bool True if forced, false if not forced.
 */
function force_ssl_content( $force = null ) {
    static $forced_content = false;

    if ( ! is_null( $force ) ) {
        $old_forced     = $forced_content;
        $forced_content = (bool) $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 site URL with proper scheme.
    }

    if ( force_ssl_content() && is_ssl() ) {
        $url = set_url_scheme( $url, 'https' );
    }

    return $url;
}

/**
 * Schedules 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' );
    }
}

/**
 * Updates 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 );
}

/**
 * Updates 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 );
}

/**
 * Updates 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 );
}

/**
 * Updates 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 );
}

/**
 * Updates the network-wide user count.
 *
 * @since 3.7.0
 * @since 4.8.0 The `$network_id` parameter has been added.
 * @since 6.0.0 This function is now a wrapper for wp_update_user_counts().
 *
 * @param int|null $network_id ID of the network. Default is the current network.
 */
function wp_update_network_user_counts( $network_id = null ) {
    wp_update_user_counts( $network_id );
}

/**
 * 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         = (int) get_site_option( 'fileupload_maxk', 1500 );
    $max_fileupload_in_bytes = KB_IN_BYTES * $fileupload_maxk;

    if ( get_site_option( 'upload_space_check_disabled' ) ) {
        return min( $size, $max_fileupload_in_bytes );
    }

    return min( $size, $max_fileupload_in_bytes, get_upload_space_available() );
}

/**
 * Determines 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 );

        $is_large_network = wp_is_large_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', $is_large_network, '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 );
}

/**
 * Sends 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_user_locale( get_current_user_id() );

    /* 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();
    }
}

/**
 * Sends 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 for an empty email address or the default 'admin_email' value.
    if ( empty( $old_email ) || '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']
    );
}