<?php
/**
 * User API: WP_Roles class
 *
 * @package WordPress
 * @subpackage Users
 * @since 4.4.0
 */

/**
 * Core class used to implement a user roles API.
 *
 * The role option is simple, the structure is organized by role name that store
 * the name in value of the 'name' key. The capabilities are stored as an array
 * in the value of the 'capability' key.
 *
 *     array (
 *          'rolename' => array (
 *              'name' => 'rolename',
 *              'capabilities' => array()
 *          )
 *     )
 *
 * @since 2.0.0
 */
class WP_Roles {
	/**
	 * List of roles and capabilities.
	 *
	 * @since 2.0.0
	 * @var array[]
	 */
	public $roles;

	/**
	 * List of the role objects.
	 *
	 * @since 2.0.0
	 * @var WP_Role[]
	 */
	public $role_objects = array();

	/**
	 * List of role names.
	 *
	 * @since 2.0.0
	 * @var string[]
	 */
	public $role_names = array();

	/**
	 * Option name for storing role list.
	 *
	 * @since 2.0.0
	 * @var string
	 */
	public $role_key;

	/**
	 * Whether to use the database for retrieval and storage.
	 *
	 * @since 2.1.0
	 * @var bool
	 */
	public $use_db = true;

	/**
	 * The site ID the roles are initialized for.
	 *
	 * @since 4.9.0
	 * @var int
	 */
	protected $site_id = 0;

	/**
	 * Constructor
	 *
	 * @since 2.0.0
	 * @since 4.9.0 The `$site_id` argument was added.
	 *
	 * @global array $wp_user_roles Used to set the 'roles' property value.
	 *
	 * @param int $site_id Site ID to initialize roles for. Default is the current site.
	 */
	public function __construct( $site_id = null ) {
		global $wp_user_roles;

		$this->use_db = empty( $wp_user_roles );

		$this->for_site( $site_id );
	}

	/**
	 * Make private/protected methods readable for backward compatibility.
	 *
	 * @since 4.0.0
	 *
	 * @param string $name      Method to call.
	 * @param array  $arguments Arguments to pass when calling.
	 * @return mixed|false Return value of the callback, false otherwise.
	 */
	public function __call( $name, $arguments ) {
		if ( '_init' === $name ) {
			return $this->_init( ...$arguments );
		}
		return false;
	}

	/**
	 * Set up the object properties.
	 *
	 * The role key is set to the current prefix for the $wpdb object with
	 * 'user_roles' appended. If the $wp_user_roles global is set, then it will
	 * be used and the role option will not be updated or used.
	 *
	 * @since 2.1.0
	 * @deprecated 4.9.0 Use WP_Roles::for_site()
	 */
	protected function _init() {
		_deprecated_function( __METHOD__, '4.9.0', 'WP_Roles::for_site()' );

		$this->for_site();
	}

	/**
	 * Reinitialize the object
	 *
	 * Recreates the role objects. This is typically called only by switch_to_blog()
	 * after switching wpdb to a new site ID.
	 *
	 * @since 3.5.0
	 * @deprecated 4.7.0 Use WP_Roles::for_site()
	 */
	public function reinit() {
		_deprecated_function( __METHOD__, '4.7.0', 'WP_Roles::for_site()' );

		$this->for_site();
	}

	/**
	 * Add role name with capabilities to list.
	 *
	 * Updates the list of roles, if the role doesn't already exist.
	 *
	 * The capabilities are defined in the following format `array( 'read' => true );`
	 * To explicitly deny a role a capability you set the value for that capability to false.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role         Role name.
	 * @param string $display_name Role display name.
	 * @param bool[] $capabilities List of capabilities keyed by the capability name,
	 *                             e.g. array( 'edit_posts' => true, 'delete_posts' => false ).
	 * @return WP_Role|void WP_Role object, if role is added.
	 */
	public function add_role( $role, $display_name, $capabilities = array() ) {
		if ( empty( $role ) || isset( $this->roles[ $role ] ) ) {
			return;
		}

		$this->roles[ $role ] = array(
			'name'         => $display_name,
			'capabilities' => $capabilities,
		);
		if ( $this->use_db ) {
			update_option( $this->role_key, $this->roles );
		}
		$this->role_objects[ $role ] = new WP_Role( $role, $capabilities );
		$this->role_names[ $role ]   = $display_name;
		return $this->role_objects[ $role ];
	}

	/**
	 * Remove role by name.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role Role name.
	 */
	public function remove_role( $role ) {
		if ( ! isset( $this->role_objects[ $role ] ) ) {
			return;
		}

		unset( $this->role_objects[ $role ] );
		unset( $this->role_names[ $role ] );
		unset( $this->roles[ $role ] );

		if ( $this->use_db ) {
			update_option( $this->role_key, $this->roles );
		}

		if ( get_option( 'default_role' ) == $role ) {
			update_option( 'default_role', 'subscriber' );
		}
	}

	/**
	 * Add capability to role.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role  Role name.
	 * @param string $cap   Capability name.
	 * @param bool   $grant Optional. Whether role is capable of performing capability.
	 *                      Default true.
	 */
	public function add_cap( $role, $cap, $grant = true ) {
		if ( ! isset( $this->roles[ $role ] ) ) {
			return;
		}

		$this->roles[ $role ]['capabilities'][ $cap ] = $grant;
		if ( $this->use_db ) {
			update_option( $this->role_key, $this->roles );
		}
	}

	/**
	 * Remove capability from role.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role Role name.
	 * @param string $cap  Capability name.
	 */
	public function remove_cap( $role, $cap ) {
		if ( ! isset( $this->roles[ $role ] ) ) {
			return;
		}

		unset( $this->roles[ $role ]['capabilities'][ $cap ] );
		if ( $this->use_db ) {
			update_option( $this->role_key, $this->roles );
		}
	}

	/**
	 * Retrieve role object by name.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role Role name.
	 * @return WP_Role|null WP_Role object if found, null if the role does not exist.
	 */
	public function get_role( $role ) {
		if ( isset( $this->role_objects[ $role ] ) ) {
			return $this->role_objects[ $role ];
		} else {
			return null;
		}
	}

	/**
	 * Retrieve list of role names.
	 *
	 * @since 2.0.0
	 *
	 * @return string[] List of role names.
	 */
	public function get_names() {
		return $this->role_names;
	}

	/**
	 * Whether role name is currently in the list of available roles.
	 *
	 * @since 2.0.0
	 *
	 * @param string $role Role name to look up.
	 * @return bool
	 */
	public function is_role( $role ) {
		return isset( $this->role_names[ $role ] );
	}

	/**
	 * Initializes all of the available roles.
	 *
	 * @since 4.9.0
	 */
	public function init_roles() {
		if ( empty( $this->roles ) ) {
			return;
		}

		$this->role_objects = array();
		$this->role_names   = array();
		foreach ( array_keys( $this->roles ) as $role ) {
			$this->role_objects[ $role ] = new WP_Role( $role, $this->roles[ $role ]['capabilities'] );
			$this->role_names[ $role ]   = $this->roles[ $role ]['name'];
		}

		/**
		 * After the roles have been initialized, allow plugins to add their own roles.
		 *
		 * @since 4.7.0
		 *
		 * @param WP_Roles $this A reference to the WP_Roles object.
		 */
		do_action( 'wp_roles_init', $this );
	}

	/**
	 * Sets the site to operate on. Defaults to the current site.
	 *
	 * @since 4.9.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param int $site_id Site ID to initialize roles for. Default is the current site.
	 */
	public function for_site( $site_id = null ) {
		global $wpdb;

		if ( ! empty( $site_id ) ) {
			$this->site_id = absint( $site_id );
		} else {
			$this->site_id = get_current_blog_id();
		}

		$this->role_key = $wpdb->get_blog_prefix( $this->site_id ) . 'user_roles';

		if ( ! empty( $this->roles ) && ! $this->use_db ) {
			return;
		}

		$this->roles = $this->get_roles_data();

		$this->init_roles();
	}

	/**
	 * Gets the ID of the site for which roles are currently initialized.
	 *
	 * @since 4.9.0
	 *
	 * @return int Site ID.
	 */
	public function get_site_id() {
		return $this->site_id;
	}

	/**
	 * Gets the available roles data.
	 *
	 * @since 4.9.0
	 *
	 * @global array $wp_user_roles Used to set the 'roles' property value.
	 *
	 * @return array Roles array.
	 */
	protected function get_roles_data() {
		global $wp_user_roles;

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

		if ( is_multisite() && get_current_blog_id() != $this->site_id ) {
			remove_action( 'switch_blog', 'wp_switch_roles_and_user', 1 );

			$roles = get_blog_option( $this->site_id, $this->role_key, array() );

			add_action( 'switch_blog', 'wp_switch_roles_and_user', 1, 2 );

			return $roles;
		}

		return get_option( $this->role_key, array() );
	}
}


<?php
/**
 * Session API: WP_Session_Tokens class
 *
 * @package WordPress
 * @subpackage Session
 * @since 4.7.0
 */

/**
 * Abstract class for managing user session tokens.
 *
 * @since 4.0.0
 */
abstract class WP_Session_Tokens {

	/**
	 * User ID.
	 *
	 * @since 4.0.0
	 * @var int User ID.
	 */
	protected $user_id;

	/**
	 * Protected constructor. Use the `get_instance()` method to get the instance.
	 *
	 * @since 4.0.0
	 *
	 * @param int $user_id User whose session to manage.
	 */
	protected function __construct( $user_id ) {
		$this->user_id = $user_id;
	}

	/**
	 * Retrieves a session manager instance for a user.
	 *
	 * This method contains a {@see 'session_token_manager'} filter, allowing a plugin to swap out
	 * the session manager for a subclass of `WP_Session_Tokens`.
	 *
	 * @since 4.0.0
	 *
	 * @param int $user_id User whose session to manage.
	 * @return WP_Session_Tokens The session object, which is by default an instance of
	 *                           the `WP_User_Meta_Session_Tokens` class.
	 */
	final public static function get_instance( $user_id ) {
		/**
		 * Filters the class name for the session token manager.
		 *
		 * @since 4.0.0
		 *
		 * @param string $session Name of class to use as the manager.
		 *                        Default 'WP_User_Meta_Session_Tokens'.
		 */
		$manager = apply_filters( 'session_token_manager', 'WP_User_Meta_Session_Tokens' );
		return new $manager( $user_id );
	}

	/**
	 * Hashes the given session token for storage.
	 *
	 * @since 4.0.0
	 *
	 * @param string $token Session token to hash.
	 * @return string A hash of the session token (a verifier).
	 */
	final private function hash_token( $token ) {
		// If ext/hash is not present, use sha1() instead.
		if ( function_exists( 'hash' ) ) {
			return hash( 'sha256', $token );
		} else {
			return sha1( $token );
		}
	}

	/**
	 * Retrieves a user's session for the given token.
	 *
	 * @since 4.0.0
	 *
	 * @param string $token Session token.
	 * @return array|null The session, or null if it does not exist.
	 */
	final public function get( $token ) {
		$verifier = $this->hash_token( $token );
		return $this->get_session( $verifier );
	}

	/**
	 * Validates the given session token for authenticity and validity.
	 *
	 * Checks that the given token is present and hasn't expired.
	 *
	 * @since 4.0.0
	 *
	 * @param string $token Token to verify.
	 * @return bool Whether the token is valid for the user.
	 */
	final public function verify( $token ) {
		$verifier = $this->hash_token( $token );
		return (bool) $this->get_session( $verifier );
	}

	/**
	 * Generates a session token and attaches session information to it.
	 *
	 * A session token is a long, random string. It is used in a cookie
	 * to link that cookie to an expiration time and to ensure the cookie
	 * becomes invalidated when the user logs out.
	 *
	 * This function generates a token and stores it with the associated
	 * expiration time (and potentially other session information via the
	 * {@see 'attach_session_information'} filter).
	 *
	 * @since 4.0.0
	 *
	 * @param int $expiration Session expiration timestamp.
	 * @return string Session token.
	 */
	final public function create( $expiration ) {
		/**
		 * Filters the information attached to the newly created session.
		 *
		 * Can be used to attach further information to a session.
		 *
		 * @since 4.0.0
		 *
		 * @param array $session Array of extra data.
		 * @param int   $user_id User ID.
		 */
		$session               = apply_filters( 'attach_session_information', array(), $this->user_id );
		$session['expiration'] = $expiration;

		// IP address.
		if ( ! empty( $_SERVER['REMOTE_ADDR'] ) ) {
			$session['ip'] = $_SERVER['REMOTE_ADDR'];
		}

		// User-agent.
		if ( ! empty( $_SERVER['HTTP_USER_AGENT'] ) ) {
			$session['ua'] = wp_unslash( $_SERVER['HTTP_USER_AGENT'] );
		}

		// Timestamp.
		$session['login'] = time();

		$token = wp_generate_password( 43, false, false );

		$this->update( $token, $session );

		return $token;
	}

	/**
	 * Updates the data for the session with the given token.
	 *
	 * @since 4.0.0
	 *
	 * @param string $token Session token to update.
	 * @param array  $session Session information.
	 */
	final public function update( $token, $session ) {
		$verifier = $this->hash_token( $token );
		$this->update_session( $verifier, $session );
	}

	/**
	 * Destroys the session with the given token.
	 *
	 * @since 4.0.0
	 *
	 * @param string $token Session token to destroy.
	 */
	final public function destroy( $token ) {
		$verifier = $this->hash_token( $token );
		$this->update_session( $verifier, null );
	}

	/**
	 * Destroys all sessions for this user except the one with the given token (presumably the one in use).
	 *
	 * @since 4.0.0
	 *
	 * @param string $token_to_keep Session token to keep.
	 */
	final public function destroy_others( $token_to_keep ) {
		$verifier = $this->hash_token( $token_to_keep );
		$session  = $this->get_session( $verifier );
		if ( $session ) {
			$this->destroy_other_sessions( $verifier );
		} else {
			$this->destroy_all_sessions();
		}
	}

	/**
	 * Determines whether a session is still valid, based on its expiration timestamp.
	 *
	 * @since 4.0.0
	 *
	 * @param array $session Session to check.
	 * @return bool Whether session is valid.
	 */
	final protected function is_still_valid( $session ) {
		return $session['expiration'] >= time();
	}

	/**
	 * Destroys all sessions for a user.
	 *
	 * @since 4.0.0
	 */
	final public function destroy_all() {
		$this->destroy_all_sessions();
	}

	/**
	 * Destroys all sessions for all users.
	 *
	 * @since 4.0.0
	 */
	final public static function destroy_all_for_all_users() {
		/** This filter is documented in wp-includes/class-wp-session-tokens.php */
		$manager = apply_filters( 'session_token_manager', 'WP_User_Meta_Session_Tokens' );
		call_user_func( array( $manager, 'drop_sessions' ) );
	}

	/**
	 * Retrieves all sessions for a user.
	 *
	 * @since 4.0.0
	 *
	 * @return array Sessions for a user.
	 */
	final public function get_all() {
		return array_values( $this->get_sessions() );
	}

	/**
	 * Retrieves all sessions of the user.
	 *
	 * @since 4.0.0
	 *
	 * @return array Sessions of the user.
	 */
	abstract protected function get_sessions();

	/**
	 * Retrieves a session based on its verifier (token hash).
	 *
	 * @since 4.0.0
	 *
	 * @param string $verifier Verifier for the session to retrieve.
	 * @return array|null The session, or null if it does not exist.
	 */
	abstract protected function get_session( $verifier );

	/**
	 * Updates a session based on its verifier (token hash).
	 *
	 * Omitting the second argument destroys the session.
	 *
	 * @since 4.0.0
	 *
	 * @param string $verifier Verifier for the session to update.
	 * @param array  $session  Optional. Session. Omitting this argument destroys the session.
	 */
	abstract protected function update_session( $verifier, $session = null );

	/**
	 * Destroys all sessions for this user, except the single session with the given verifier.
	 *
	 * @since 4.0.0
	 *
	 * @param string $verifier Verifier of the session to keep.
	 */
	abstract protected function destroy_other_sessions( $verifier );

	/**
	 * Destroys all sessions for the user.
	 *
	 * @since 4.0.0
	 */
	abstract protected function destroy_all_sessions();

	/**
	 * Destroys all sessions for all users.
	 *
	 * @since 4.0.0
	 */
	public static function drop_sessions() {}
}


<?php
/**
 * Feed API: WP_SimplePie_File class
 *
 * @package WordPress
 * @subpackage Feed
 * @since 4.7.0
 */

/**
 * Core class for fetching remote files and reading local files with SimplePie.
 *
 * @since 2.8.0
 *
 * @see SimplePie_File
 */
class WP_SimplePie_File extends SimplePie_File {

	/**
	 * Constructor.
	 *
	 * @since 2.8.0
	 * @since 3.2.0 Updated to use a PHP5 constructor.
	 *
	 * @param string       $url             Remote file URL.
	 * @param integer      $timeout         Optional. How long the connection should stay open in seconds.
	 *                                      Default 10.
	 * @param integer      $redirects       Optional. The number of allowed redirects. Default 5.
	 * @param string|array $headers         Optional. Array or string of headers to send with the request.
	 *                                      Default null.
	 * @param string       $useragent       Optional. User-agent value sent. Default null.
	 * @param boolean      $force_fsockopen Optional. Whether to force opening internet or unix domain socket
	 *                                      connection or not. Default false.
	 */
	public function __construct( $url, $timeout = 10, $redirects = 5, $headers = null, $useragent = null, $force_fsockopen = false ) {
		$this->url       = $url;
		$this->timeout   = $timeout;
		$this->redirects = $redirects;
		$this->headers   = $headers;
		$this->useragent = $useragent;

		$this->method = SIMPLEPIE_FILE_SOURCE_REMOTE;

		if ( preg_match( '/^http(s)?:\/\//i', $url ) ) {
			$args = array(
				'timeout'     => $this->timeout,
				'redirection' => $this->redirects,
			);

			if ( ! empty( $this->headers ) ) {
				$args['headers'] = $this->headers;
			}

			if ( SIMPLEPIE_USERAGENT != $this->useragent ) { // Use default WP user agent unless custom has been specified.
				$args['user-agent'] = $this->useragent;
			}

			$res = wp_safe_remote_request( $url, $args );

			if ( is_wp_error( $res ) ) {
				$this->error   = 'WP HTTP Error: ' . $res->get_error_message();
				$this->success = false;
			} else {
				$this->headers     = wp_remote_retrieve_headers( $res );
				$this->body        = wp_remote_retrieve_body( $res );
				$this->status_code = wp_remote_retrieve_response_code( $res );
			}
		} else {
			$this->error   = '';
			$this->success = false;
		}
	}
}


<?php
/**
 * Feed API: WP_SimplePie_Sanitize_KSES class
 *
 * @package WordPress
 * @subpackage Feed
 * @since 4.7.0
 */

/**
 * Core class used to implement SimpliePie feed sanitization.
 *
 * Extends the SimplePie_Sanitize class to use KSES, because
 * we cannot universally count on DOMDocument being available.
 *
 * @since 3.5.0
 *
 * @see SimplePie_Sanitize
 */
class WP_SimplePie_Sanitize_KSES extends SimplePie_Sanitize {

	/**
	 * WordPress SimplePie sanitization using KSES.
	 *
	 * Sanitizes the incoming data, to ensure that it matches the type of data expected, using KSES.
	 *
	 * @since 3.5.0
	 *
	 * @param mixed   $data The data that needs to be sanitized.
	 * @param integer $type The type of data that it's supposed to be.
	 * @param string  $base Optional. The `xml:base` value to use when converting relative
	 *                      URLs to absolute ones. Default empty.
	 * @return mixed Sanitized data.
	 */
	public function sanitize( $data, $type, $base = '' ) {
		$data = trim( $data );
		if ( $type & SIMPLEPIE_CONSTRUCT_MAYBE_HTML ) {
			if ( preg_match( '/(&(#(x[0-9a-fA-F]+|[0-9]+)|[a-zA-Z0-9]+)|<\/[A-Za-z][^\x09\x0A\x0B\x0C\x0D\x20\x2F\x3E]*' . SIMPLEPIE_PCRE_HTML_ATTRIBUTE . '>)/', $data ) ) {
				$type |= SIMPLEPIE_CONSTRUCT_HTML;
			} else {
				$type |= SIMPLEPIE_CONSTRUCT_TEXT;
			}
		}
		if ( $type & SIMPLEPIE_CONSTRUCT_BASE64 ) {
			$data = base64_decode( $data );
		}
		if ( $type & ( SIMPLEPIE_CONSTRUCT_HTML | SIMPLEPIE_CONSTRUCT_XHTML ) ) {
			$data = wp_kses_post( $data );
			if ( 'UTF-8' !== $this->output_encoding ) {
				$data = $this->registry->call( 'Misc', 'change_encoding', array( $data, 'UTF-8', $this->output_encoding ) );
			}
			return $data;
		} else {
			return parent::sanitize( $data, $type, $base );
		}
	}
}


<?php
/**
 * Site API: WP_Site_Query class
 *
 * @package WordPress
 * @subpackage Sites
 * @since 4.6.0
 */

/**
 * Core class used for querying sites.
 *
 * @since 4.6.0
 *
 * @see WP_Site_Query::__construct() for accepted arguments.
 */
class WP_Site_Query {

	/**
	 * SQL for database query.
	 *
	 * @since 4.6.0
	 * @var string
	 */
	public $request;

	/**
	 * SQL query clauses.
	 *
	 * @since 4.6.0
	 * @var array
	 */
	protected $sql_clauses = array(
		'select'  => '',
		'from'    => '',
		'where'   => array(),
		'groupby' => '',
		'orderby' => '',
		'limits'  => '',
	);

	/**
	 * Metadata query container.
	 *
	 * @since 5.1.0
	 * @var WP_Meta_Query
	 */
	public $meta_query = false;

	/**
	 * Metadata query clauses.
	 *
	 * @since 5.1.0
	 * @var array
	 */
	protected $meta_query_clauses;

	/**
	 * Date query container.
	 *
	 * @since 4.6.0
	 * @var WP_Date_Query A date query instance.
	 */
	public $date_query = false;

	/**
	 * Query vars set by the user.
	 *
	 * @since 4.6.0
	 * @var array
	 */
	public $query_vars;

	/**
	 * Default values for query vars.
	 *
	 * @since 4.6.0
	 * @var array
	 */
	public $query_var_defaults;

	/**
	 * List of sites located by the query.
	 *
	 * @since 4.6.0
	 * @var array
	 */
	public $sites;

	/**
	 * The amount of found sites for the current query.
	 *
	 * @since 4.6.0
	 * @var int
	 */
	public $found_sites = 0;

	/**
	 * The number of pages.
	 *
	 * @since 4.6.0
	 * @var int
	 */
	public $max_num_pages = 0;

	/**
	 * Sets up the site query, based on the query vars passed.
	 *
	 * @since 4.6.0
	 * @since 4.8.0 Introduced the 'lang_id', 'lang__in', and 'lang__not_in' parameters.
	 * @since 5.1.0 Introduced the 'update_site_meta_cache', 'meta_query', 'meta_key',
	 *              'meta_value', 'meta_type' and 'meta_compare' parameters.
	 *
	 * @param string|array $query {
	 *     Optional. Array or query string of site query parameters. Default empty.
	 *
	 *     @type array        $site__in               Array of site IDs to include. Default empty.
	 *     @type array        $site__not_in           Array of site IDs to exclude. Default empty.
	 *     @type bool         $count                  Whether to return a site count (true) or array of site objects.
	 *                                                Default false.
	 *     @type array        $date_query             Date query clauses to limit sites by. See WP_Date_Query.
	 *                                                Default null.
	 *     @type string       $fields                 Site fields to return. Accepts 'ids' (returns an array of site IDs)
	 *                                                or empty (returns an array of complete site objects). Default empty.
	 *     @type int          $ID                     A site ID to only return that site. Default empty.
	 *     @type int          $number                 Maximum number of sites to retrieve. Default 100.
	 *     @type int          $offset                 Number of sites to offset the query. Used to build LIMIT clause.
	 *                                                Default 0.
	 *     @type bool         $no_found_rows          Whether to disable the `SQL_CALC_FOUND_ROWS` query. Default true.
	 *     @type string|array $orderby                Site status or array of statuses. Accepts 'id', 'domain', 'path',
	 *                                                'network_id', 'last_updated', 'registered', 'domain_length',
	 *                                                'path_length', 'site__in' and 'network__in'. Also accepts false,
	 *                                                an empty array, or 'none' to disable `ORDER BY` clause.
	 *                                                Default 'id'.
	 *     @type string       $order                  How to order retrieved sites. Accepts 'ASC', 'DESC'. Default 'ASC'.
	 *     @type int          $network_id             Limit results to those affiliated with a given network ID. If 0,
	 *                                                include all networks. Default 0.
	 *     @type array        $network__in            Array of network IDs to include affiliated sites for. Default empty.
	 *     @type array        $network__not_in        Array of network IDs to exclude affiliated sites for. Default empty.
	 *     @type string       $domain                 Limit results to those affiliated with a given domain. Default empty.
	 *     @type array        $domain__in             Array of domains to include affiliated sites for. Default empty.
	 *     @type array        $domain__not_in         Array of domains to exclude affiliated sites for. Default empty.
	 *     @type string       $path                   Limit results to those affiliated with a given path. Default empty.
	 *     @type array        $path__in               Array of paths to include affiliated sites for. Default empty.
	 *     @type array        $path__not_in           Array of paths to exclude affiliated sites for. Default empty.
	 *     @type int          $public                 Limit results to public sites. Accepts '1' or '0'. Default empty.
	 *     @type int          $archived               Limit results to archived sites. Accepts '1' or '0'. Default empty.
	 *     @type int          $mature                 Limit results to mature sites. Accepts '1' or '0'. Default empty.
	 *     @type int          $spam                   Limit results to spam sites. Accepts '1' or '0'. Default empty.
	 *     @type int          $deleted                Limit results to deleted sites. Accepts '1' or '0'. Default empty.
	 *     @type int          $lang_id                Limit results to a language ID. Default empty.
	 *     @type array        $lang__in               Array of language IDs to include affiliated sites for. Default empty.
	 *     @type array        $lang__not_in           Array of language IDs to exclude affiliated sites for. Default empty.
	 *     @type string       $search                 Search term(s) to retrieve matching sites for. Default empty.
	 *     @type array        $search_columns         Array of column names to be searched. Accepts 'domain' and 'path'.
	 *                                                Default empty array.
	 *     @type bool         $update_site_cache      Whether to prime the cache for found sites. Default true.
	 *     @type bool         $update_site_meta_cache Whether to prime the metadata cache for found sites. Default true.
	 *     @type array        $meta_query             Meta query clauses to limit retrieved sites by. See `WP_Meta_Query`.
	 *                                                Default empty.
	 *     @type string       $meta_key               Limit sites to those matching a specific metadata key.
	 *                                                Can be used in conjunction with `$meta_value`. Default empty.
	 *     @type string       $meta_value             Limit sites to those matching a specific metadata value.
	 *                                                Usually used in conjunction with `$meta_key`. Default empty.
	 *     @type string       $meta_type              Data type that the `$meta_value` column will be CAST to for
	 *                                                comparisons. Default empty.
	 *     @type string       $meta_compare           Comparison operator to test the `$meta_value`. Default empty.
	 * }
	 */
	public function __construct( $query = '' ) {
		$this->query_var_defaults = array(
			'fields'                 => '',
			'ID'                     => '',
			'site__in'               => '',
			'site__not_in'           => '',
			'number'                 => 100,
			'offset'                 => '',
			'no_found_rows'          => true,
			'orderby'                => 'id',
			'order'                  => 'ASC',
			'network_id'             => 0,
			'network__in'            => '',
			'network__not_in'        => '',
			'domain'                 => '',
			'domain__in'             => '',
			'domain__not_in'         => '',
			'path'                   => '',
			'path__in'               => '',
			'path__not_in'           => '',
			'public'                 => null,
			'archived'               => null,
			'mature'                 => null,
			'spam'                   => null,
			'deleted'                => null,
			'lang_id'                => null,
			'lang__in'               => '',
			'lang__not_in'           => '',
			'search'                 => '',
			'search_columns'         => array(),
			'count'                  => false,
			'date_query'             => null, // See WP_Date_Query.
			'update_site_cache'      => true,
			'update_site_meta_cache' => true,
			'meta_query'             => '',
			'meta_key'               => '',
			'meta_value'             => '',
			'meta_type'              => '',
			'meta_compare'           => '',
		);

		if ( ! empty( $query ) ) {
			$this->query( $query );
		}
	}

	/**
	 * Parses arguments passed to the site query with default query parameters.
	 *
	 * @since 4.6.0
	 *
	 * @see WP_Site_Query::__construct()
	 *
	 * @param string|array $query Array or string of WP_Site_Query arguments. See WP_Site_Query::__construct().
	 */
	public function parse_query( $query = '' ) {
		if ( empty( $query ) ) {
			$query = $this->query_vars;
		}

		$this->query_vars = wp_parse_args( $query, $this->query_var_defaults );

		/**
		 * Fires after the site query vars have been parsed.
		 *
		 * @since 4.6.0
		 *
		 * @param WP_Site_Query $this The WP_Site_Query instance (passed by reference).
		 */
		do_action_ref_array( 'parse_site_query', array( &$this ) );
	}

	/**
	 * Sets up the WordPress query for retrieving sites.
	 *
	 * @since 4.6.0
	 *
	 * @param string|array $query Array or URL query string of parameters.
	 * @return array|int List of WP_Site objects, a list of site IDs when 'fields' is set to 'ids',
	 *                   or the number of sites when 'count' is passed as a query var.
	 */
	public function query( $query ) {
		$this->query_vars = wp_parse_args( $query );

		return $this->get_sites();
	}

	/**
	 * Retrieves a list of sites matching the query vars.
	 *
	 * @since 4.6.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @return array|int List of WP_Site objects, a list of site IDs when 'fields' is set to 'ids',
	 *                   or the number of sites when 'count' is passed as a query var.
	 */
	public function get_sites() {
		global $wpdb;

		$this->parse_query();

		// Parse meta query.
		$this->meta_query = new WP_Meta_Query();
		$this->meta_query->parse_query_vars( $this->query_vars );

		/**
		 * Fires before sites are retrieved.
		 *
		 * @since 4.6.0
		 *
		 * @param WP_Site_Query $this Current instance of WP_Site_Query (passed by reference).
		 */
		do_action_ref_array( 'pre_get_sites', array( &$this ) );

		// Reparse query vars, in case they were modified in a 'pre_get_sites' callback.
		$this->meta_query->parse_query_vars( $this->query_vars );
		if ( ! empty( $this->meta_query->queries ) ) {
			$this->meta_query_clauses = $this->meta_query->get_sql( 'blog', $wpdb->blogs, 'blog_id', $this );
		}

		$site_data = null;

		/**
		 * Filter the site data before the get_sites query takes place.
		 *
		 * Return a non-null value to bypass WordPress's default site queries.
		 *
		 * The expected return type from this filter depends on the value passed in the request query_vars:
		 * When `$this->query_vars['count']` is set, the filter should return the site count as an int.
		 * When `'ids' === $this->query_vars['fields']`, the filter should return an array of site IDs.
		 * Otherwise the filter should return an array of WP_Site objects.
		 *
		 * @since 5.2.0
		 *
		 * @param array|int|null $site_data Return an array of site data to short-circuit WP's site query,
		 *                                  the site count as an integer if `$this->query_vars['count']` is set,
		 *                                  or null to run the normal queries.
		 * @param WP_Site_Query  $this      The WP_Site_Query instance, passed by reference.
		 */
		$site_data = apply_filters_ref_array( 'sites_pre_query', array( $site_data, &$this ) );

		if ( null !== $site_data ) {
			return $site_data;
		}

		// $args can include anything. Only use the args defined in the query_var_defaults to compute the key.
		$_args = wp_array_slice_assoc( $this->query_vars, array_keys( $this->query_var_defaults ) );

		// Ignore the $fields argument as the queried result will be the same regardless.
		unset( $_args['fields'] );

		$key          = md5( serialize( $_args ) );
		$last_changed = wp_cache_get_last_changed( 'sites' );

		$cache_key   = "get_sites:$key:$last_changed";
		$cache_value = wp_cache_get( $cache_key, 'sites' );

		if ( false === $cache_value ) {
			$site_ids = $this->get_site_ids();
			if ( $site_ids ) {
				$this->set_found_sites();
			}

			$cache_value = array(
				'site_ids'    => $site_ids,
				'found_sites' => $this->found_sites,
			);
			wp_cache_add( $cache_key, $cache_value, 'sites' );
		} else {
			$site_ids          = $cache_value['site_ids'];
			$this->found_sites = $cache_value['found_sites'];
		}

		if ( $this->found_sites && $this->query_vars['number'] ) {
			$this->max_num_pages = ceil( $this->found_sites / $this->query_vars['number'] );
		}

		// If querying for a count only, there's nothing more to do.
		if ( $this->query_vars['count'] ) {
			// $site_ids is actually a count in this case.
			return intval( $site_ids );
		}

		$site_ids = array_map( 'intval', $site_ids );

		if ( 'ids' === $this->query_vars['fields'] ) {
			$this->sites = $site_ids;

			return $this->sites;
		}

		// Prime site network caches.
		if ( $this->query_vars['update_site_cache'] ) {
			_prime_site_caches( $site_ids, $this->query_vars['update_site_meta_cache'] );
		}

		// Fetch full site objects from the primed cache.
		$_sites = array();
		foreach ( $site_ids as $site_id ) {
			$_site = get_site( $site_id );
			if ( $_site ) {
				$_sites[] = $_site;
			}
		}

		/**
		 * Filters the site query results.
		 *
		 * @since 4.6.0
		 *
		 * @param WP_Site[]     $_sites An array of WP_Site objects.
		 * @param WP_Site_Query $this   Current instance of WP_Site_Query (passed by reference).
		 */
		$_sites = apply_filters_ref_array( 'the_sites', array( $_sites, &$this ) );

		// Convert to WP_Site instances.
		$this->sites = array_map( 'get_site', $_sites );

		return $this->sites;
	}

	/**
	 * Used internally to get a list of site IDs matching the query vars.
	 *
	 * @since 4.6.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @return int|array A single count of site IDs if a count query. An array of site IDs if a full query.
	 */
	protected function get_site_ids() {
		global $wpdb;

		$order = $this->parse_order( $this->query_vars['order'] );

		// Disable ORDER BY with 'none', an empty array, or boolean false.
		if ( in_array( $this->query_vars['orderby'], array( 'none', array(), false ), true ) ) {
			$orderby = '';
		} elseif ( ! empty( $this->query_vars['orderby'] ) ) {
			$ordersby = is_array( $this->query_vars['orderby'] ) ?
				$this->query_vars['orderby'] :
				preg_split( '/[,\s]/', $this->query_vars['orderby'] );

			$orderby_array = array();
			foreach ( $ordersby as $_key => $_value ) {
				if ( ! $_value ) {
					continue;
				}

				if ( is_int( $_key ) ) {
					$_orderby = $_value;
					$_order   = $order;
				} else {
					$_orderby = $_key;
					$_order   = $_value;
				}

				$parsed = $this->parse_orderby( $_orderby );

				if ( ! $parsed ) {
					continue;
				}

				if ( 'site__in' === $_orderby || 'network__in' === $_orderby ) {
					$orderby_array[] = $parsed;
					continue;
				}

				$orderby_array[] = $parsed . ' ' . $this->parse_order( $_order );
			}

			$orderby = implode( ', ', $orderby_array );
		} else {
			$orderby = "{$wpdb->blogs}.blog_id $order";
		}

		$number = absint( $this->query_vars['number'] );
		$offset = absint( $this->query_vars['offset'] );
		$limits = '';

		if ( ! empty( $number ) ) {
			if ( $offset ) {
				$limits = 'LIMIT ' . $offset . ',' . $number;
			} else {
				$limits = 'LIMIT ' . $number;
			}
		}

		if ( $this->query_vars['count'] ) {
			$fields = 'COUNT(*)';
		} else {
			$fields = "{$wpdb->blogs}.blog_id";
		}

		// Parse site IDs for an IN clause.
		$site_id = absint( $this->query_vars['ID'] );
		if ( ! empty( $site_id ) ) {
			$this->sql_clauses['where']['ID'] = $wpdb->prepare( "{$wpdb->blogs}.blog_id = %d", $site_id );
		}

		// Parse site IDs for an IN clause.
		if ( ! empty( $this->query_vars['site__in'] ) ) {
			$this->sql_clauses['where']['site__in'] = "{$wpdb->blogs}.blog_id IN ( " . implode( ',', wp_parse_id_list( $this->query_vars['site__in'] ) ) . ' )';
		}

		// Parse site IDs for a NOT IN clause.
		if ( ! empty( $this->query_vars['site__not_in'] ) ) {
			$this->sql_clauses['where']['site__not_in'] = "{$wpdb->blogs}.blog_id NOT IN ( " . implode( ',', wp_parse_id_list( $this->query_vars['site__not_in'] ) ) . ' )';
		}

		$network_id = absint( $this->query_vars['network_id'] );

		if ( ! empty( $network_id ) ) {
			$this->sql_clauses['where']['network_id'] = $wpdb->prepare( 'site_id = %d', $network_id );
		}

		// Parse site network IDs for an IN clause.
		if ( ! empty( $this->query_vars['network__in'] ) ) {
			$this->sql_clauses['where']['network__in'] = 'site_id IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['network__in'] ) ) . ' )';
		}

		// Parse site network IDs for a NOT IN clause.
		if ( ! empty( $this->query_vars['network__not_in'] ) ) {
			$this->sql_clauses['where']['network__not_in'] = 'site_id NOT IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['network__not_in'] ) ) . ' )';
		}

		if ( ! empty( $this->query_vars['domain'] ) ) {
			$this->sql_clauses['where']['domain'] = $wpdb->prepare( 'domain = %s', $this->query_vars['domain'] );
		}

		// Parse site domain for an IN clause.
		if ( is_array( $this->query_vars['domain__in'] ) ) {
			$this->sql_clauses['where']['domain__in'] = "domain IN ( '" . implode( "', '", $wpdb->_escape( $this->query_vars['domain__in'] ) ) . "' )";
		}

		// Parse site domain for a NOT IN clause.
		if ( is_array( $this->query_vars['domain__not_in'] ) ) {
			$this->sql_clauses['where']['domain__not_in'] = "domain NOT IN ( '" . implode( "', '", $wpdb->_escape( $this->query_vars['domain__not_in'] ) ) . "' )";
		}

		if ( ! empty( $this->query_vars['path'] ) ) {
			$this->sql_clauses['where']['path'] = $wpdb->prepare( 'path = %s', $this->query_vars['path'] );
		}

		// Parse site path for an IN clause.
		if ( is_array( $this->query_vars['path__in'] ) ) {
			$this->sql_clauses['where']['path__in'] = "path IN ( '" . implode( "', '", $wpdb->_escape( $this->query_vars['path__in'] ) ) . "' )";
		}

		// Parse site path for a NOT IN clause.
		if ( is_array( $this->query_vars['path__not_in'] ) ) {
			$this->sql_clauses['where']['path__not_in'] = "path NOT IN ( '" . implode( "', '", $wpdb->_escape( $this->query_vars['path__not_in'] ) ) . "' )";
		}

		if ( is_numeric( $this->query_vars['archived'] ) ) {
			$archived                               = absint( $this->query_vars['archived'] );
			$this->sql_clauses['where']['archived'] = $wpdb->prepare( 'archived = %s ', absint( $archived ) );
		}

		if ( is_numeric( $this->query_vars['mature'] ) ) {
			$mature                               = absint( $this->query_vars['mature'] );
			$this->sql_clauses['where']['mature'] = $wpdb->prepare( 'mature = %d ', $mature );
		}

		if ( is_numeric( $this->query_vars['spam'] ) ) {
			$spam                               = absint( $this->query_vars['spam'] );
			$this->sql_clauses['where']['spam'] = $wpdb->prepare( 'spam = %d ', $spam );
		}

		if ( is_numeric( $this->query_vars['deleted'] ) ) {
			$deleted                               = absint( $this->query_vars['deleted'] );
			$this->sql_clauses['where']['deleted'] = $wpdb->prepare( 'deleted = %d ', $deleted );
		}

		if ( is_numeric( $this->query_vars['public'] ) ) {
			$public                               = absint( $this->query_vars['public'] );
			$this->sql_clauses['where']['public'] = $wpdb->prepare( 'public = %d ', $public );
		}

		if ( is_numeric( $this->query_vars['lang_id'] ) ) {
			$lang_id                               = absint( $this->query_vars['lang_id'] );
			$this->sql_clauses['where']['lang_id'] = $wpdb->prepare( 'lang_id = %d ', $lang_id );
		}

		// Parse site language IDs for an IN clause.
		if ( ! empty( $this->query_vars['lang__in'] ) ) {
			$this->sql_clauses['where']['lang__in'] = 'lang_id IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['lang__in'] ) ) . ' )';
		}

		// Parse site language IDs for a NOT IN clause.
		if ( ! empty( $this->query_vars['lang__not_in'] ) ) {
			$this->sql_clauses['where']['lang__not_in'] = 'lang_id NOT IN ( ' . implode( ',', wp_parse_id_list( $this->query_vars['lang__not_in'] ) ) . ' )';
		}

		// Falsey search strings are ignored.
		if ( strlen( $this->query_vars['search'] ) ) {
			$search_columns = array();

			if ( $this->query_vars['search_columns'] ) {
				$search_columns = array_intersect( $this->query_vars['search_columns'], array( 'domain', 'path' ) );
			}

			if ( ! $search_columns ) {
				$search_columns = array( 'domain', 'path' );
			}

			/**
			 * Filters the columns to search in a WP_Site_Query search.
			 *
			 * The default columns include 'domain' and 'path.
			 *
			 * @since 4.6.0
			 *
			 * @param string[]      $search_columns Array of column names to be searched.
			 * @param string        $search         Text being searched.
			 * @param WP_Site_Query $this           The current WP_Site_Query instance.
			 */
			$search_columns = apply_filters( 'site_search_columns', $search_columns, $this->query_vars['search'], $this );

			$this->sql_clauses['where']['search'] = $this->get_search_sql( $this->query_vars['search'], $search_columns );
		}

		$date_query = $this->query_vars['date_query'];
		if ( ! empty( $date_query ) && is_array( $date_query ) ) {
			$this->date_query                         = new WP_Date_Query( $date_query, 'registered' );
			$this->sql_clauses['where']['date_query'] = preg_replace( '/^\s*AND\s*/', '', $this->date_query->get_sql() );
		}

		$join    = '';
		$groupby = '';

		if ( ! empty( $this->meta_query_clauses ) ) {
			$join .= $this->meta_query_clauses['join'];

			// Strip leading 'AND'.
			$this->sql_clauses['where']['meta_query'] = preg_replace( '/^\s*AND\s*/', '', $this->meta_query_clauses['where'] );

			if ( ! $this->query_vars['count'] ) {
				$groupby = "{$wpdb->blogs}.blog_id";
			}
		}

		$where = implode( ' AND ', $this->sql_clauses['where'] );

		$pieces = array( 'fields', 'join', 'where', 'orderby', 'limits', 'groupby' );

		/**
		 * Filters the site query clauses.
		 *
		 * @since 4.6.0
		 *
		 * @param string[]      $pieces An associative array of site query clauses.
		 * @param WP_Site_Query $this   Current instance of WP_Site_Query (passed by reference).
		 */
		$clauses = apply_filters_ref_array( 'sites_clauses', array( compact( $pieces ), &$this ) );

		$fields  = isset( $clauses['fields'] ) ? $clauses['fields'] : '';
		$join    = isset( $clauses['join'] ) ? $clauses['join'] : '';
		$where   = isset( $clauses['where'] ) ? $clauses['where'] : '';
		$orderby = isset( $clauses['orderby'] ) ? $clauses['orderby'] : '';
		$limits  = isset( $clauses['limits'] ) ? $clauses['limits'] : '';
		$groupby = isset( $clauses['groupby'] ) ? $clauses['groupby'] : '';

		if ( $where ) {
			$where = 'WHERE ' . $where;
		}

		if ( $groupby ) {
			$groupby = 'GROUP BY ' . $groupby;
		}

		if ( $orderby ) {
			$orderby = "ORDER BY $orderby";
		}

		$found_rows = '';
		if ( ! $this->query_vars['no_found_rows'] ) {
			$found_rows = 'SQL_CALC_FOUND_ROWS';
		}

		$this->sql_clauses['select']  = "SELECT $found_rows $fields";
		$this->sql_clauses['from']    = "FROM $wpdb->blogs $join";
		$this->sql_clauses['groupby'] = $groupby;
		$this->sql_clauses['orderby'] = $orderby;
		$this->sql_clauses['limits']  = $limits;

		$this->request = "{$this->sql_clauses['select']} {$this->sql_clauses['from']} {$where} {$this->sql_clauses['groupby']} {$this->sql_clauses['orderby']} {$this->sql_clauses['limits']}";

		if ( $this->query_vars['count'] ) {
			return intval( $wpdb->get_var( $this->request ) );
		}

		$site_ids = $wpdb->get_col( $this->request );

		return array_map( 'intval', $site_ids );
	}

	/**
	 * Populates found_sites and max_num_pages properties for the current query
	 * if the limit clause was used.
	 *
	 * @since 4.6.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 */
	private function set_found_sites() {
		global $wpdb;

		if ( $this->query_vars['number'] && ! $this->query_vars['no_found_rows'] ) {
			/**
			 * Filters the query used to retrieve found site count.
			 *
			 * @since 4.6.0
			 *
			 * @param string        $found_sites_query SQL query. Default 'SELECT FOUND_ROWS()'.
			 * @param WP_Site_Query $site_query        The `WP_Site_Query` instance.
			 */
			$found_sites_query = apply_filters( 'found_sites_query', 'SELECT FOUND_ROWS()', $this );

			$this->found_sites = (int) $wpdb->get_var( $found_sites_query );
		}
	}

	/**
	 * Used internally to generate an SQL string for searching across multiple columns.
	 *
	 * @since 4.6.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param string   $string  Search string.
	 * @param string[] $columns Array of columns to search.
	 * @return string Search SQL.
	 */
	protected function get_search_sql( $string, $columns ) {
		global $wpdb;

		if ( false !== strpos( $string, '*' ) ) {
			$like = '%' . implode( '%', array_map( array( $wpdb, 'esc_like' ), explode( '*', $string ) ) ) . '%';
		} else {
			$like = '%' . $wpdb->esc_like( $string ) . '%';
		}

		$searches = array();
		foreach ( $columns as $column ) {
			$searches[] = $wpdb->prepare( "$column LIKE %s", $like );
		}

		return '(' . implode( ' OR ', $searches ) . ')';
	}

	/**
	 * Parses and sanitizes 'orderby' keys passed to the site query.
	 *
	 * @since 4.6.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param string $orderby Alias for the field to order by.
	 * @return string|false Value to used in the ORDER clause. False otherwise.
	 */
	protected function parse_orderby( $orderby ) {
		global $wpdb;

		$parsed = false;

		switch ( $orderby ) {
			case 'site__in':
				$site__in = implode( ',', array_map( 'absint', $this->query_vars['site__in'] ) );
				$parsed   = "FIELD( {$wpdb->blogs}.blog_id, $site__in )";
				break;
			case 'network__in':
				$network__in = implode( ',', array_map( 'absint', $this->query_vars['network__in'] ) );
				$parsed      = "FIELD( {$wpdb->blogs}.site_id, $network__in )";
				break;
			case 'domain':
			case 'last_updated':
			case 'path':
			case 'registered':
				$parsed = $orderby;
				break;
			case 'network_id':
				$parsed = 'site_id';
				break;
			case 'domain_length':
				$parsed = 'CHAR_LENGTH(domain)';
				break;
			case 'path_length':
				$parsed = 'CHAR_LENGTH(path)';
				break;
			case 'id':
				$parsed = "{$wpdb->blogs}.blog_id";
				break;
		}

		if ( ! empty( $parsed ) || empty( $this->meta_query_clauses ) ) {
			return $parsed;
		}

		$meta_clauses = $this->meta_query->get_clauses();
		if ( empty( $meta_clauses ) ) {
			return $parsed;
		}

		$primary_meta_query = reset( $meta_clauses );
		if ( ! empty( $primary_meta_query['key'] ) && $primary_meta_query['key'] === $orderby ) {
			$orderby = 'meta_value';
		}

		switch ( $orderby ) {
			case 'meta_value':
				if ( ! empty( $primary_meta_query['type'] ) ) {
					$parsed = "CAST({$primary_meta_query['alias']}.meta_value AS {$primary_meta_query['cast']})";
				} else {
					$parsed = "{$primary_meta_query['alias']}.meta_value";
				}
				break;
			case 'meta_value_num':
				$parsed = "{$primary_meta_query['alias']}.meta_value+0";
				break;
			default:
				if ( isset( $meta_clauses[ $orderby ] ) ) {
					$meta_clause = $meta_clauses[ $orderby ];
					$parsed      = "CAST({$meta_clause['alias']}.meta_value AS {$meta_clause['cast']})";
				}
		}

		return $parsed;
	}

	/**
	 * Parses an 'order' query variable and cast it to 'ASC' or 'DESC' as necessary.
	 *
	 * @since 4.6.0
	 *
	 * @param string $order The 'order' query variable.
	 * @return string The sanitized 'order' query variable.
	 */
	protected function parse_order( $order ) {
		if ( ! is_string( $order ) || empty( $order ) ) {
			return 'ASC';
		}

		if ( 'ASC' === strtoupper( $order ) ) {
			return 'ASC';
		} else {
			return 'DESC';
		}
	}
}


<?php
/**
 * Site API: WP_Site class
 *
 * @package WordPress
 * @subpackage Multisite
 * @since 4.5.0
 */

/**
 * Core class used for interacting with a multisite site.
 *
 * This class is used during load to populate the `$current_blog` global and
 * setup the current site.
 *
 * @since 4.5.0
 *
 * @property int    $id
 * @property int    $network_id
 * @property string $blogname
 * @property string $siteurl
 * @property int    $post_count
 * @property string $home
 */
final class WP_Site {

	/**
	 * Site ID.
	 *
	 * A numeric string, for compatibility reasons.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $blog_id;

	/**
	 * Domain of the site.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $domain = '';

	/**
	 * Path of the site.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $path = '';

	/**
	 * The ID of the site's parent network.
	 *
	 * Named "site" vs. "network" for legacy reasons. An individual site's "site" is
	 * its network.
	 *
	 * A numeric string, for compatibility reasons.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $site_id = '0';

	/**
	 * The date on which the site was created or registered.
	 *
	 * @since 4.5.0
	 * @var string Date in MySQL's datetime format.
	 */
	public $registered = '0000-00-00 00:00:00';

	/**
	 * The date and time on which site settings were last updated.
	 *
	 * @since 4.5.0
	 * @var string Date in MySQL's datetime format.
	 */
	public $last_updated = '0000-00-00 00:00:00';

	/**
	 * Whether the site should be treated as public.
	 *
	 * A numeric string, for compatibility reasons.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $public = '1';

	/**
	 * Whether the site should be treated as archived.
	 *
	 * A numeric string, for compatibility reasons.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $archived = '0';

	/**
	 * Whether the site should be treated as mature.
	 *
	 * Handling for this does not exist throughout WordPress core, but custom
	 * implementations exist that require the property to be present.
	 *
	 * A numeric string, for compatibility reasons.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $mature = '0';

	/**
	 * Whether the site should be treated as spam.
	 *
	 * A numeric string, for compatibility reasons.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $spam = '0';

	/**
	 * Whether the site should be treated as deleted.
	 *
	 * A numeric string, for compatibility reasons.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $deleted = '0';

	/**
	 * The language pack associated with this site.
	 *
	 * A numeric string, for compatibility reasons.
	 *
	 * @since 4.5.0
	 * @var string
	 */
	public $lang_id = '0';

	/**
	 * Retrieves a site from the database by its ID.
	 *
	 * @since 4.5.0
	 *
	 * @global wpdb $wpdb WordPress database abstraction object.
	 *
	 * @param int $site_id The ID of the site to retrieve.
	 * @return WP_Site|false The site's object if found. False if not.
	 */
	public static function get_instance( $site_id ) {
		global $wpdb;

		$site_id = (int) $site_id;
		if ( ! $site_id ) {
			return false;
		}

		$_site = wp_cache_get( $site_id, 'sites' );

		if ( false === $_site ) {
			$_site = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM {$wpdb->blogs} WHERE blog_id = %d LIMIT 1", $site_id ) );

			if ( empty( $_site ) || is_wp_error( $_site ) ) {
				$_site = -1;
			}

			wp_cache_add( $site_id, $_site, 'sites' );
		}

		if ( is_numeric( $_site ) ) {
			return false;
		}

		return new WP_Site( $_site );
	}

	/**
	 * Creates a new WP_Site object.
	 *
	 * Will populate object properties from the object provided and assign other
	 * default properties based on that information.
	 *
	 * @since 4.5.0
	 *
	 * @param WP_Site|object $site A site object.
	 */
	public function __construct( $site ) {
		foreach ( get_object_vars( $site ) as $key => $value ) {
			$this->$key = $value;
		}
	}

	/**
	 * Converts an object to array.
	 *
	 * @since 4.6.0
	 *
	 * @return array Object as array.
	 */
	public function to_array() {
		return get_object_vars( $this );
	}

	/**
	 * Getter.
	 *
	 * Allows current multisite naming conventions when getting properties.
	 * Allows access to extended site properties.
	 *
	 * @since 4.6.0
	 *
	 * @param string $key Property to get.
	 * @return mixed Value of the property. Null if not available.
	 */
	public function __get( $key ) {
		switch ( $key ) {
			case 'id':
				return (int) $this->blog_id;
			case 'network_id':
				return (int) $this->site_id;
			case 'blogname':
			case 'siteurl':
			case 'post_count':
			case 'home':
			default: // Custom properties added by 'site_details' filter.
				if ( ! did_action( 'ms_loaded' ) ) {
					return null;
				}

				$details = $this->get_details();
				if ( isset( $details->$key ) ) {
					return $details->$key;
				}
		}

		return null;
	}

	/**
	 * Isset-er.
	 *
	 * Allows current multisite naming conventions when checking for properties.
	 * Checks for extended site properties.
	 *
	 * @since 4.6.0
	 *
	 * @param string $key Property to check if set.
	 * @return bool Whether the property is set.
	 */
	public function __isset( $key ) {
		switch ( $key ) {
			case 'id':
			case 'network_id':
				return true;
			case 'blogname':
			case 'siteurl':
			case 'post_count':
			case 'home':
				if ( ! did_action( 'ms_loaded' ) ) {
					return false;
				}
				return true;
			default: // Custom properties added by 'site_details' filter.
				if ( ! did_action( 'ms_loaded' ) ) {
					return false;
				}

				$details = $this->get_details();
				if ( isset( $details->$key ) ) {
					return true;
				}
		}

		return false;
	}

	/**
	 * Setter.
	 *
	 * Allows current multisite naming conventions while setting properties.
	 *
	 * @since 4.6.0
	 *
	 * @param string $key   Property to set.
	 * @param mixed  $value Value to assign to the property.
	 */
	public function __set( $key, $value ) {
		switch ( $key ) {
			case 'id':
				$this->blog_id = (string) $value;
				break;
			case 'network_id':
				$this->site_id = (string) $value;
				break;
			default:
				$this->$key = $value;
		}
	}

	/**
	 * Retrieves the details for this site.
	 *
	 * This method is used internally to lazy-load the extended properties of a site.
	 *
	 * @since 4.6.0
	 *
	 * @see WP_Site::__get()
	 *
	 * @return stdClass A raw site object with all details included.
	 */
	private function get_details() {
		$details = wp_cache_get( $this->blog_id, 'site-details' );

		if ( false === $details ) {

			switch_to_blog( $this->blog_id );
			// Create a raw copy of the object for backward compatibility with the filter below.
			$details = new stdClass();
			foreach ( get_object_vars( $this ) as $key => $value ) {
				$details->$key = $value;
			}
			$details->blogname   = get_option( 'blogname' );
			$details->siteurl    = get_option( 'siteurl' );
			$details->post_count = get_option( 'post_count' );
			$details->home       = get_option( 'home' );
			restore_current_blog();

			wp_cache_set( $this->blog_id, $details, 'site-details' );
		}

		/** This filter is documented in wp-includes/ms-blogs.php */
		$details = apply_filters_deprecated( 'blog_details', array( $details ), '4.7.0', 'site_details' );

		/**
		 * Filters a site's extended properties.
		 *
		 * @since 4.6.0
		 *
		 * @param stdClass $details The site details.
		 */
		$details = apply_filters( 'site_details', $details );

		return $details;
	}
}


<?php
/**
 * Taxonomy API: WP_Tax_Query class
 *
 * @package WordPress
 * @subpackage Taxonomy
 * @since 4.4.0
 */

/**
 * Core class used to implement taxonomy queries for the Taxonomy API.
 *
 * Used for generating SQL clauses that filter a primary query according to object
 * taxonomy terms.
 *
 * WP_Tax_Query is a helper that allows primary query classes, such as WP_Query, to filter
 * their results by object metadata, by generating `JOIN` and `WHERE` subclauses to be
 * attached to the primary SQL query string.
 *
 * @since 3.1.0
 */
class WP_Tax_Query {

	/**
	 * Array of taxonomy queries.
	 *
	 * See WP_Tax_Query::__construct() for information on tax query arguments.
	 *
	 * @since 3.1.0
	 * @var array
	 */
	public $queries = array();

	/**
	 * The relation between the queries. Can be one of 'AND' or 'OR'.
	 *
	 * @since 3.1.0
	 * @var string
	 */
	public $relation;

	/**
	 * Standard response when the query should not return any rows.
	 *
	 * @since 3.2.0
	 * @var string
	 */
	private static $no_results = array(
		'join'  => array( '' ),
		'where' => array( '0 = 1' ),
	);

	/**
	 * A flat list of table aliases used in the JOIN clauses.
	 *
	 * @since 4.1.0
	 * @var array
	 */
	protected $table_aliases = array();

	/**
	 * Terms and taxonomies fetched by this query.
	 *
	 * We store this data in a flat array because they are referenced in a
	 * number of places by WP_Query.
	 *
	 * @since 4.1.0
	 * @var array
	 */
	public $queried_terms = array();

	/**
	 * Database table that where the metadata's objects are stored (eg $wpdb->users).
	 *
	 * @since 4.1.0
	 * @var string
	 */
	public $primary_table;

	/**
	 * Column in 'primary_table' that represents the ID of the object.
	 *
	 * @since 4.1.0
	 * @var string
	 */
	public $primary_id_column;

	/**
	 * Constructor.
	 *
	 * @since 3.1.0
	 * @since 4.1.0 Added support for `$operator` 'NOT EXISTS' and 'EXISTS' values.
	 *
	 * @param array $tax_query {
	 *     Array of taxonomy query clauses.
	 *
	 *     @type string $relation Optional. The MySQL keyword used to join
	 *                            the clauses of the query. Accepts 'AND', or 'OR'. Default 'AND'.
	 *     @type array  ...$0 {
	 *         An array of first-order clause parameters, or another fully-formed tax query.
	 *
	 *         @type string           $taxonomy         Taxonomy being queried. Optional when field=term_taxonomy_id.
	 *         @type string|int|array $terms            Term or terms to filter by.
	 *         @type string           $field            Field to match $terms against. Accepts 'term_id', 'slug',
	 *                                                 'name', or 'term_taxonomy_id'. Default: 'term_id'.
	 *         @type string           $operator         MySQL operator to be used with $terms in the WHERE clause.
	 *                                                  Accepts 'AND', 'IN', 'NOT IN', 'EXISTS', 'NOT EXISTS'.
	 *                                                  Default: 'IN'.
	 *         @type bool             $include_children Optional. Whether to include child terms.
	 *                                                  Requires a $taxonomy. Default: true.
	 *     }
	 * }
	 */
	public function __construct( $tax_query ) {
		if ( isset( $tax_query['relation'] ) ) {
			$this->relation = $this->sanitize_relation( $tax_query['relation'] );
		} else {
			$this->relation = 'AND';
		}

		$this->queries = $this->sanitize_query( $tax_query );
	}

	/**
	 * Ensure the 'tax_query' argument passed to the class constructor is well-formed.
	 *
	 * Ensures that each query-level clause has a 'relation' key, and that
	 * each first-order clause contains all the necessary keys from `$defaults`.
	 *
	 * @since 4.1.0
	 *
	 * @param array $queries Array of queries clauses.
	 * @return array Sanitized array of query clauses.
	 */
	public function sanitize_query( $queries ) {
		$cleaned_query = array();

		$defaults = array(
			'taxonomy'         => '',
			'terms'            => array(),
			'field'            => 'term_id',
			'operator'         => 'IN',
			'include_children' => true,
		);

		foreach ( $queries as $key => $query ) {
			if ( 'relation' === $key ) {
				$cleaned_query['relation'] = $this->sanitize_relation( $query );

				// First-order clause.
			} elseif ( self::is_first_order_clause( $query ) ) {

				$cleaned_clause          = array_merge( $defaults, $query );
				$cleaned_clause['terms'] = (array) $cleaned_clause['terms'];
				$cleaned_query[]         = $cleaned_clause;

				/*
				 * Keep a copy of the clause in the flate
				 * $queried_terms array, for use in WP_Query.
				 */
				if ( ! empty( $cleaned_clause['taxonomy'] ) && 'NOT IN' !== $cleaned_clause['operator'] ) {
					$taxonomy = $cleaned_clause['taxonomy'];
					if ( ! isset( $this->queried_terms[ $taxonomy ] ) ) {
						$this->queried_terms[ $taxonomy ] = array();
					}

					/*
					 * Backward compatibility: Only store the first
					 * 'terms' and 'field' found for a given taxonomy.
					 */
					if ( ! empty( $cleaned_clause['terms'] ) && ! isset( $this->queried_terms[ $taxonomy ]['terms'] ) ) {
						$this->queried_terms[ $taxonomy ]['terms'] = $cleaned_clause['terms'];
					}

					if ( ! empty( $cleaned_clause['field'] ) && ! isset( $this->queried_terms[ $taxonomy ]['field'] ) ) {
						$this->queried_terms[ $taxonomy ]['field'] = $cleaned_clause['field'];
					}
				}

				// Otherwise, it's a nested query, so we recurse.
			} elseif ( is_array( $query ) ) {
				$cleaned_subquery = $this->sanitize_query( $query );

				if ( ! empty( $cleaned_subquery ) ) {
					// All queries with children must have a relation.
					if ( ! isset( $cleaned_subquery['relation'] ) ) {
						$cleaned_subquery['relation'] = 'AND';
					}

					$cleaned_query[] = $cleaned_subquery;
				}
			}
		}

		return $cleaned_query;
	}

	/**
	 * Sanitize a 'relation' operator.
	 *
	 * @since 4.1.0
	 *
	 * @param string $relation Raw relation key from the query argument.
	 * @return string Sanitized relation ('AND' or 'OR').
	 */
	public function sanitize_relation( $relation ) {
		if ( 'OR' === strtoupper( $relation ) ) {
			return 'OR';
		} else {
			return 'AND';
		}
	}

	/**
	 * Determine whether a clause is first-order.
	 *
	 * A "first-order" clause is one that contains any of the first-order
	 * clause keys ('terms', 'taxonomy', 'include_children', 'field',
	 * 'operator'). An empty clause also counts as a first-order clause,
	 * for backward compatibility. Any clause that doesn't meet this is
	 * determined, by process of elimination, to be a higher-order query.
	 *
	 * @since 4.1.0
	 *
	 * @param array $query Tax query arguments.
	 * @return bool Whether the query clause is a first-order clause.
	 */
	protected static function is_first_order_clause( $query ) {
		return is_array( $query ) && ( empty( $query ) || array_key_exists( 'terms', $query ) || array_key_exists( 'taxonomy', $query ) || array_key_exists( 'include_children', $query ) || array_key_exists( 'field', $query ) || array_key_exists( 'operator', $query ) );
	}

	/**
	 * Generates SQL clauses to be appended to a main query.
	 *
	 * @since 3.1.0
	 *
	 * @param string $primary_table     Database table where the object being filtered is stored (eg wp_users).
	 * @param string $primary_id_column ID column for the filtered object in $primary_table.
	 * @return array {
	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.
	 *
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
	 *     @type string $where SQL fragment to append to the main WHERE clause.
	 * }
	 */
	public function get_sql( $primary_table, $primary_id_column ) {
		$this->primary_table     = $primary_table;
		$this->primary_id_column = $primary_id_column;

		return $this->get_sql_clauses();
	}

	/**
	 * Generate SQL clauses to be appended to a main query.
	 *
	 * Called by the public WP_Tax_Query::get_sql(), this method
	 * is abstracted out to maintain parity with the other Query classes.
	 *
	 * @since 4.1.0
	 *
	 * @return array {
	 *     Array containing JOIN and WHERE SQL clauses to append to the main query.
	 *
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
	 *     @type string $where SQL fragment to append to the main WHERE clause.
	 * }
	 */
	protected function get_sql_clauses() {
		/*
		 * $queries are passed by reference to get_sql_for_query() for recursion.
		 * To keep $this->queries unaltered, pass a copy.
		 */
		$queries = $this->queries;
		$sql     = $this->get_sql_for_query( $queries );

		if ( ! empty( $sql['where'] ) ) {
			$sql['where'] = ' AND ' . $sql['where'];
		}

		return $sql;
	}

	/**
	 * Generate SQL clauses for a single query array.
	 *
	 * If nested subqueries are found, this method recurses the tree to
	 * produce the properly nested SQL.
	 *
	 * @since 4.1.0
	 *
	 * @param array $query Query to parse (passed by reference).
	 * @param int   $depth Optional. Number of tree levels deep we currently are.
	 *                     Used to calculate indentation. Default 0.
	 * @return array {
	 *     Array containing JOIN and WHERE SQL clauses to append to a single query array.
	 *
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
	 *     @type string $where SQL fragment to append to the main WHERE clause.
	 * }
	 */
	protected function get_sql_for_query( &$query, $depth = 0 ) {
		$sql_chunks = array(
			'join'  => array(),
			'where' => array(),
		);

		$sql = array(
			'join'  => '',
			'where' => '',
		);

		$indent = '';
		for ( $i = 0; $i < $depth; $i++ ) {
			$indent .= '  ';
		}

		foreach ( $query as $key => &$clause ) {
			if ( 'relation' === $key ) {
				$relation = $query['relation'];
			} elseif ( is_array( $clause ) ) {

				// This is a first-order clause.
				if ( $this->is_first_order_clause( $clause ) ) {
					$clause_sql = $this->get_sql_for_clause( $clause, $query );

					$where_count = count( $clause_sql['where'] );
					if ( ! $where_count ) {
						$sql_chunks['where'][] = '';
					} elseif ( 1 === $where_count ) {
						$sql_chunks['where'][] = $clause_sql['where'][0];
					} else {
						$sql_chunks['where'][] = '( ' . implode( ' AND ', $clause_sql['where'] ) . ' )';
					}

					$sql_chunks['join'] = array_merge( $sql_chunks['join'], $clause_sql['join'] );
					// This is a subquery, so we recurse.
				} else {
					$clause_sql = $this->get_sql_for_query( $clause, $depth + 1 );

					$sql_chunks['where'][] = $clause_sql['where'];
					$sql_chunks['join'][]  = $clause_sql['join'];
				}
			}
		}

		// Filter to remove empties.
		$sql_chunks['join']  = array_filter( $sql_chunks['join'] );
		$sql_chunks['where'] = array_filter( $sql_chunks['where'] );

		if ( empty( $relation ) ) {
			$relation = 'AND';
		}

		// Filter duplicate JOIN clauses and combine into a single string.
		if ( ! empty( $sql_chunks['join'] ) ) {
			$sql['join'] = implode( ' ', array_unique( $sql_chunks['join'] ) );
		}

		// Generate a single WHERE clause with proper brackets and indentation.
		if ( ! empty( $sql_chunks['where'] ) ) {
			$sql['where'] = '( ' . "\n  " . $indent . implode( ' ' . "\n  " . $indent . $relation . ' ' . "\n  " . $indent, $sql_chunks['where'] ) . "\n" . $indent . ')';
		}

		return $sql;
	}

	/**
	 * Generate SQL JOIN and WHERE clauses for a "first-order" query clause.
	 *
	 * @since 4.1.0
	 *
	 * @global wpdb $wpdb The WordPress database abstraction object.
	 *
	 * @param array $clause       Query clause (passed by reference).
	 * @param array $parent_query Parent query array.
	 * @return array {
	 *     Array containing JOIN and WHERE SQL clauses to append to a first-order query.
	 *
	 *     @type string $join  SQL fragment to append to the main JOIN clause.
	 *     @type string $where SQL fragment to append to the main WHERE clause.
	 * }
	 */
	public function get_sql_for_clause( &$clause, $parent_query ) {
		global $wpdb;

		$sql = array(
			'where' => array(),
			'join'  => array(),
		);

		$join  = '';
		$where = '';

		$this->clean_query( $clause );

		if ( is_wp_error( $clause ) ) {
			return self::$no_results;
		}

		$terms    = $clause['terms'];
		$operator = strtoupper( $clause['operator'] );

		if ( 'IN' === $operator ) {

			if ( empty( $terms ) ) {
				return self::$no_results;
			}

			$terms = implode( ',', $terms );

			/*
			 * Before creating another table join, see if this clause has a
			 * sibling with an existing join that can be shared.
			 */
			$alias = $this->find_compatible_table_alias( $clause, $parent_query );
			if ( false === $alias ) {
				$i     = count( $this->table_aliases );
				$alias = $i ? 'tt' . $i : $wpdb->term_relationships;

				// Store the alias as part of a flat array to build future iterators.
				$this->table_aliases[] = $alias;

				// Store the alias with this clause, so later siblings can use it.
				$clause['alias'] = $alias;

				$join .= " LEFT JOIN $wpdb->term_relationships";
				$join .= $i ? " AS $alias" : '';
				$join .= " ON ($this->primary_table.$this->primary_id_column = $alias.object_id)";
			}

			$where = "$alias.term_taxonomy_id $operator ($terms)";

		} elseif ( 'NOT IN' === $operator ) {

			if ( empty( $terms ) ) {
				return $sql;
			}

			$terms = implode( ',', $terms );

			$where = "$this->primary_table.$this->primary_id_column NOT IN (
				SELECT object_id
				FROM $wpdb->term_relationships
				WHERE term_taxonomy_id IN ($terms)
			)";

		} elseif ( 'AND' === $operator ) {

			if ( empty( $terms ) ) {
				return $sql;
			}

			$num_terms = count( $terms );

			$terms = implode( ',', $terms );

			$where = "(
				SELECT COUNT(1)
				FROM $wpdb->term_relationships
				WHERE term_taxonomy_id IN ($terms)
				AND object_id = $this->primary_table.$this->primary_id_column
			) = $num_terms";

		} elseif ( 'NOT EXISTS' === $operator || 'EXISTS' === $operator ) {

			$where = $wpdb->prepare(
				"$operator (
				SELECT 1
				FROM $wpdb->term_relationships
				INNER JOIN $wpdb->term_taxonomy
				ON $wpdb->term_taxonomy.term_taxonomy_id = $wpdb->term_relationships.term_taxonomy_id
				WHERE $wpdb->term_taxonomy.taxonomy = %s
				AND $wpdb->term_relationships.object_id = $this->primary_table.$this->primary_id_column
			)",
				$clause['taxonomy']
			);

		}

		$sql['join'][]  = $join;
		$sql['where'][] = $where;
		return $sql;
	}

	/**
	 * Identify an existing table alias that is compatible with the current query clause.
	 *
	 * We avoid unnecessary table joins by allowing each clause to look for
	 * an existing table alias that is compatible with the query that it
	 * needs to perform.
	 *
	 * An existing alias is compatible if (a) it is a sibling of `$clause`
	 * (ie, it's under the scope of the same relation), and (b) the combination
	 * of operator and relation between the clauses allows for a shared table
	 * join. In the case of WP_Tax_Query, this only applies to 'IN'
	 * clauses that are connected by the relation 'OR'.
	 *
	 * @since 4.1.0
	 *
	 * @param array $clause       Query clause.
	 * @param array $parent_query Parent query of $clause.
	 * @return string|false Table alias if found, otherwise false.
	 */
	protected function find_compatible_table_alias( $clause, $parent_query ) {
		$alias = false;

		// Sanity check. Only IN queries use the JOIN syntax.
		if ( ! isset( $clause['operator'] ) || 'IN' !== $clause['operator'] ) {
			return $alias;
		}

		// Since we're only checking IN queries, we're only concerned with OR relations.
		if ( ! isset( $parent_query['relation'] ) || 'OR' !== $parent_query['relation'] ) {
			return $alias;
		}

		$compatible_operators = array( 'IN' );

		foreach ( $parent_query as $sibling ) {
			if ( ! is_array( $sibling ) || ! $this->is_first_order_clause( $sibling ) ) {
				continue;
			}

			if ( empty( $sibling['alias'] ) || empty( $sibling['operator'] ) ) {
				continue;
			}

			// The sibling must both have compatible operator to share its alias.
			if ( in_array( strtoupper( $sibling['operator'] ), $compatible_operators, true ) ) {
				$alias = $sibling['alias'];
				break;
			}
		}

		return $alias;
	}

	/**
	 * Validates a single query.
	 *
	 * @since 3.2.0
	 *
	 * @param array $query The single query. Passed by reference.
	 */
	private function clean_query( &$query ) {
		if ( empty( $query['taxonomy'] ) ) {
			if ( 'term_taxonomy_id' !== $query['field'] ) {
				$query = new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
				return;
			}

			// So long as there are shared terms, 'include_children' requires that a taxonomy is set.
			$query['include_children'] = false;
		} elseif ( ! taxonomy_exists( $query['taxonomy'] ) ) {
			$query = new WP_Error( 'invalid_taxonomy', __( 'Invalid taxonomy.' ) );
			return;
		}

		$query['terms'] = array_unique( (array) $query['terms'] );

		if ( is_taxonomy_hierarchical( $query['taxonomy'] ) && $query['include_children'] ) {
			$this->transform_query( $query, 'term_id' );

			if ( is_wp_error( $query ) ) {
				return;
			}

			$children = array();
			foreach ( $query['terms'] as $term ) {
				$children   = array_merge( $children, get_term_children( $term, $query['taxonomy'] ) );
				$children[] = $term;
			}
			$query['terms'] = $children;
		}

		$this->transform_query( $query, 'term_taxonomy_id' );
	}

	/**
	 * Transforms a single query, from one field to another.
	 *
	 * Operates on the `$query` object by reference. In the case of error,
	 * `$query` is converted to a WP_Error object.
	 *
	 * @since 3.2.0
	 *
	 * @global wpdb $wpdb The WordPress database abstraction object.
	 *
	 * @param array  $query           The single query. Passed by reference.
	 * @param string $resulting_field The resulting field. Accepts 'slug', 'name', 'term_taxonomy_id',
	 *                                or 'term_id'. Default 'term_id'.
	 */
	public function transform_query( &$query, $resulting_field ) {
		if ( empty( $query['terms'] ) ) {
			return;
		}

		if ( $query['field'] == $resulting_field ) {
			return;
		}

		$resulting_field = sanitize_key( $resulting_field );

		// Empty 'terms' always results in a null transformation.
		$terms = array_filter( $query['terms'] );
		if ( empty( $terms ) ) {
			$query['terms'] = array();
			$query['field'] = $resulting_field;
			return;
		}

		$args = array(
			'get'                    => 'all',
			'number'                 => 0,
			'taxonomy'               => $query['taxonomy'],
			'update_term_meta_cache' => false,
			'orderby'                => 'none',
		);

		// Term query parameter name depends on the 'field' being searched on.
		switch ( $query['field'] ) {
			case 'slug':
				$args['slug'] = $terms;
				break;
			case 'name':
				$args['name'] = $terms;
				break;
			case 'term_taxonomy_id':
				$args['term_taxonomy_id'] = $terms;
				break;
			default:
				$args['include'] = wp_parse_id_list( $terms );
				break;
		}

		$term_query = new WP_Term_Query();
		$term_list  = $term_query->query( $args );

		if ( is_wp_error( $term_list ) ) {
			$query = $term_list;
			return;
		}

		if ( 'AND' === $query['operator'] && count( $term_list ) < count( $query['terms'] ) ) {
			$query = new WP_Error( 'inexistent_terms', __( 'Inexistent terms.' ) );
			return;
		}

		$query['terms'] = wp_list_pluck( $term_list, $resulting_field );
		$query['field'] = $resulting_field;
	}
}


<?php
/**
 * Taxonomy API: WP_Taxonomy class
 *
 * @package WordPress
 * @subpackage Taxonomy
 * @since 4.7.0
 */

/**
 * Core class used for interacting with taxonomies.
 *
 * @since 4.7.0
 */
final class WP_Taxonomy {
	/**
	 * Taxonomy key.
	 *
	 * @since 4.7.0
	 * @var string
	 */
	public $name;

	/**
	 * Name of the taxonomy shown in the menu. Usually plural.
	 *
	 * @since 4.7.0
	 * @var string
	 */
	public $label;

	/**
	 * Labels object for this taxonomy.
	 *
	 * If not set, tag labels are inherited for non-hierarchical types
	 * and category labels for hierarchical ones.
	 *
	 * @see get_taxonomy_labels()
	 *
	 * @since 4.7.0
	 * @var object
	 */
	public $labels;

	/**
	 * A short descriptive summary of what the taxonomy is for.
	 *
	 * @since 4.7.0
	 * @var string
	 */
	public $description = '';

	/**
	 * Whether a taxonomy is intended for use publicly either via the admin interface or by front-end users.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $public = true;

	/**
	 * Whether the taxonomy is publicly queryable.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $publicly_queryable = true;

	/**
	 * Whether the taxonomy is hierarchical.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $hierarchical = false;

	/**
	 * Whether to generate and allow a UI for managing terms in this taxonomy in the admin.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $show_ui = true;

	/**
	 * Whether to show the taxonomy in the admin menu.
	 *
	 * If true, the taxonomy is shown as a submenu of the object type menu. If false, no menu is shown.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $show_in_menu = true;

	/**
	 * Whether the taxonomy is available for selection in navigation menus.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $show_in_nav_menus = true;

	/**
	 * Whether to list the taxonomy in the tag cloud widget controls.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $show_tagcloud = true;

	/**
	 * Whether to show the taxonomy in the quick/bulk edit panel.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $show_in_quick_edit = true;

	/**
	 * Whether to display a column for the taxonomy on its post type listing screens.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $show_admin_column = false;

	/**
	 * The callback function for the meta box display.
	 *
	 * @since 4.7.0
	 * @var bool|callable
	 */
	public $meta_box_cb = null;

	/**
	 * The callback function for sanitizing taxonomy data saved from a meta box.
	 *
	 * @since 5.1.0
	 * @var callable
	 */
	public $meta_box_sanitize_cb = null;

	/**
	 * An array of object types this taxonomy is registered for.
	 *
	 * @since 4.7.0
	 * @var array
	 */
	public $object_type = null;

	/**
	 * Capabilities for this taxonomy.
	 *
	 * @since 4.7.0
	 * @var object
	 */
	public $cap;

	/**
	 * Rewrites information for this taxonomy.
	 *
	 * @since 4.7.0
	 * @var array|false
	 */
	public $rewrite;

	/**
	 * Query var string for this taxonomy.
	 *
	 * @since 4.7.0
	 * @var string|false
	 */
	public $query_var;

	/**
	 * Function that will be called when the count is updated.
	 *
	 * @since 4.7.0
	 * @var callable
	 */
	public $update_count_callback;

	/**
	 * Whether this taxonomy should appear in the REST API.
	 *
	 * Default false. If true, standard endpoints will be registered with
	 * respect to $rest_base and $rest_controller_class.
	 *
	 * @since 4.7.4
	 * @var bool $show_in_rest
	 */
	public $show_in_rest;

	/**
	 * The base path for this taxonomy's REST API endpoints.
	 *
	 * @since 4.7.4
	 * @var string|bool $rest_base
	 */
	public $rest_base;

	/**
	 * The controller for this taxonomy's REST API endpoints.
	 *
	 * Custom controllers must extend WP_REST_Controller.
	 *
	 * @since 4.7.4
	 * @var string|bool $rest_controller_class
	 */
	public $rest_controller_class;

	/**
	 * The default term name for this taxonomy. If you pass an array you have
	 * to set 'name' and optionally 'slug' and 'description'.
	 *
	 * @since 5.5.0
	 * @var array|string
	 */
	public $default_term;

	/**
	 * The controller instance for this taxonomy's REST API endpoints.
	 *
	 * Lazily computed. Should be accessed using {@see WP_Taxonomy::get_rest_controller()}.
	 *
	 * @since 5.5.0
	 * @var WP_REST_Controller $rest_controller
	 */
	public $rest_controller;

	/**
	 * Whether it is a built-in taxonomy.
	 *
	 * @since 4.7.0
	 * @var bool
	 */
	public $_builtin;

	/**
	 * Constructor.
	 *
	 * @since 4.7.0
	 *
	 * @global WP $wp Current WordPress environment instance.
	 *
	 * @param string       $taxonomy    Taxonomy key, must not exceed 32 characters.
	 * @param array|string $object_type Name of the object type for the taxonomy object.
	 * @param array|string $args        Optional. Array or query string of arguments for registering a taxonomy.
	 *                                  Default empty array.
	 */
	public function __construct( $taxonomy, $object_type, $args = array() ) {
		$this->name = $taxonomy;

		$this->set_props( $object_type, $args );
	}

	/**
	 * Sets taxonomy properties.
	 *
	 * @since 4.7.0
	 *
	 * @param array|string $object_type Name of the object type for the taxonomy object.
	 * @param array|string $args        Array or query string of arguments for registering a taxonomy.
	 */
	public function set_props( $object_type, $args ) {
		$args = wp_parse_args( $args );

		/**
		 * Filters the arguments for registering a taxonomy.
		 *
		 * @since 4.4.0
		 *
		 * @param array    $args        Array of arguments for registering a taxonomy.
		 * @param string   $taxonomy    Taxonomy key.
		 * @param string[] $object_type Array of names of object types for the taxonomy.
		 */
		$args = apply_filters( 'register_taxonomy_args', $args, $this->name, (array) $object_type );

		$defaults = array(
			'labels'                => array(),
			'description'           => '',
			'public'                => true,
			'publicly_queryable'    => null,
			'hierarchical'          => false,
			'show_ui'               => null,
			'show_in_menu'          => null,
			'show_in_nav_menus'     => null,
			'show_tagcloud'         => null,
			'show_in_quick_edit'    => null,
			'show_admin_column'     => false,
			'meta_box_cb'           => null,
			'meta_box_sanitize_cb'  => null,
			'capabilities'          => array(),
			'rewrite'               => true,
			'query_var'             => $this->name,
			'update_count_callback' => '',
			'show_in_rest'          => false,
			'rest_base'             => false,
			'rest_controller_class' => false,
			'default_term'          => null,
			'_builtin'              => false,
		);

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

		// If not set, default to the setting for 'public'.
		if ( null === $args['publicly_queryable'] ) {
			$args['publicly_queryable'] = $args['public'];
		}

		if ( false !== $args['query_var'] && ( is_admin() || false !== $args['publicly_queryable'] ) ) {
			if ( true === $args['query_var'] ) {
				$args['query_var'] = $this->name;
			} else {
				$args['query_var'] = sanitize_title_with_dashes( $args['query_var'] );
			}
		} else {
			// Force 'query_var' to false for non-public taxonomies.
			$args['query_var'] = false;
		}

		if ( false !== $args['rewrite'] && ( is_admin() || get_option( 'permalink_structure' ) ) ) {
			$args['rewrite'] = wp_parse_args(
				$args['rewrite'],
				array(
					'with_front'   => true,
					'hierarchical' => false,
					'ep_mask'      => EP_NONE,
				)
			);

			if ( empty( $args['rewrite']['slug'] ) ) {
				$args['rewrite']['slug'] = sanitize_title_with_dashes( $this->name );
			}
		}

		// If not set, default to the setting for 'public'.
		if ( null === $args['show_ui'] ) {
			$args['show_ui'] = $args['public'];
		}

		// If not set, default to the setting for 'show_ui'.
		if ( null === $args['show_in_menu'] || ! $args['show_ui'] ) {
			$args['show_in_menu'] = $args['show_ui'];
		}

		// If not set, default to the setting for 'public'.
		if ( null === $args['show_in_nav_menus'] ) {
			$args['show_in_nav_menus'] = $args['public'];
		}

		// If not set, default to the setting for 'show_ui'.
		if ( null === $args['show_tagcloud'] ) {
			$args['show_tagcloud'] = $args['show_ui'];
		}

		// If not set, default to the setting for 'show_ui'.
		if ( null === $args['show_in_quick_edit'] ) {
			$args['show_in_quick_edit'] = $args['show_ui'];
		}

		$default_caps = array(
			'manage_terms' => 'manage_categories',
			'edit_terms'   => 'manage_categories',
			'delete_terms' => 'manage_categories',
			'assign_terms' => 'edit_posts',
		);

		$args['cap'] = (object) array_merge( $default_caps, $args['capabilities'] );
		unset( $args['capabilities'] );

		$args['object_type'] = array_unique( (array) $object_type );

		// If not set, use the default meta box.
		if ( null === $args['meta_box_cb'] ) {
			if ( $args['hierarchical'] ) {
				$args['meta_box_cb'] = 'post_categories_meta_box';
			} else {
				$args['meta_box_cb'] = 'post_tags_meta_box';
			}
		}

		$args['name'] = $this->name;

		// Default meta box sanitization callback depends on the value of 'meta_box_cb'.
		if ( null === $args['meta_box_sanitize_cb'] ) {
			switch ( $args['meta_box_cb'] ) {
				case 'post_categories_meta_box':
					$args['meta_box_sanitize_cb'] = 'taxonomy_meta_box_sanitize_cb_checkboxes';
					break;

				case 'post_tags_meta_box':
				default:
					$args['meta_box_sanitize_cb'] = 'taxonomy_meta_box_sanitize_cb_input';
					break;
			}
		}

		// Default taxonomy term.
		if ( ! empty( $args['default_term'] ) ) {
			if ( ! is_array( $args['default_term'] ) ) {
				$args['default_term'] = array( 'name' => $args['default_term'] );
			}
			$args['default_term'] = wp_parse_args(
				$args['default_term'],
				array(
					'name'        => '',
					'slug'        => '',
					'description' => '',
				)
			);
		}

		foreach ( $args as $property_name => $property_value ) {
			$this->$property_name = $property_value;
		}

		$this->labels = get_taxonomy_labels( $this );
		$this->label  = $this->labels->name;
	}

	/**
	 * Adds the necessary rewrite rules for the taxonomy.
	 *
	 * @since 4.7.0
	 *
	 * @global WP $wp Current WordPress environment instance.
	 */
	public function add_rewrite_rules() {
		/* @var WP $wp */
		global $wp;

		// Non-publicly queryable taxonomies should not register query vars, except in the admin.
		if ( false !== $this->query_var && $wp ) {
			$wp->add_query_var( $this->query_var );
		}

		if ( false !== $this->rewrite && ( is_admin() || get_option( 'permalink_structure' ) ) ) {
			if ( $this->hierarchical && $this->rewrite['hierarchical'] ) {
				$tag = '(.+?)';
			} else {
				$tag = '([^/]+)';
			}

			add_rewrite_tag( "%$this->name%", $tag, $this->query_var ? "{$this->query_var}=" : "taxonomy=$this->name&term=" );
			add_permastruct( $this->name, "{$this->rewrite['slug']}/%$this->name%", $this->rewrite );
		}
	}

	/**
	 * Removes any rewrite rules, permastructs, and rules for the taxonomy.
	 *
	 * @since 4.7.0
	 *
	 * @global WP $wp Current WordPress environment instance.
	 */
	public function remove_rewrite_rules() {
		/* @var WP $wp */
		global $wp;

		// Remove query var.
		if ( false !== $this->query_var ) {
			$wp->remove_query_var( $this->query_var );
		}

		// Remove rewrite tags and permastructs.
		if ( false !== $this->rewrite ) {
			remove_rewrite_tag( "%$this->name%" );
			remove_permastruct( $this->name );
		}
	}

	/**
	 * Registers the ajax callback for the meta box.
	 *
	 * @since 4.7.0
	 */
	public function add_hooks() {
		add_filter( 'wp_ajax_add-' . $this->name, '_wp_ajax_add_hierarchical_term' );
	}

	/**
	 * Removes the ajax callback for the meta box.
	 *
	 * @since 4.7.0
	 */
	public function remove_hooks() {
		remove_filter( 'wp_ajax_add-' . $this->name, '_wp_ajax_add_hierarchical_term' );
	}

	/**
	 * Gets the REST API controller for this taxonomy.
	 *
	 * Will only instantiate the controller class once per request.
	 *
	 * @since 5.5.0
	 *
	 * @return WP_REST_Controller|null The controller instance, or null if the taxonomy
	 *                                 is set not to show in rest.
	 */
	public function get_rest_controller() {
		if ( ! $this->show_in_rest ) {
			return null;
		}

		$class = $this->rest_controller_class ? $this->rest_controller_class : WP_REST_Terms_Controller::class;

		if ( ! class_exists( $class ) ) {
			return null;
		}

		if ( ! is_subclass_of( $class, WP_REST_Controller::class ) ) {
			return null;
		}

		if ( ! $this->rest_controller ) {
			$this->rest_controller = new $class( $this->name );
		}

		if ( ! ( $this->rest_controller instanceof $class ) ) {
			return null;
		}

		return $this->rest_controller;
	}
}