<?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;

			}