hpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
		/**
		 * Tells the client to sync all options to the server
		 *
		 * @since 4.2.0
		 *
		 * @param boolean Whether to expand options (should always be true)
		 */
		do_action( 'jetpack_full_sync_options', true );

		// The number of actions enqueued, and next module state (true == done).
		return array( 1, true );
	}

	/**
	 * Send the options actions for full sync.
	 *
	 * @access public
	 *
	 * @param array $config Full sync configuration for this sync module.
	 * @param int   $send_until The timestamp until the current request can send.
	 * @param array $state This module Full Sync status.
	 *
	 * @return array This module Full Sync status.
	 */
	public function send_full_sync_actions( $config, $send_until, $state ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
		// we call this instead of do_action when sending immediately.
		$this->send_action( 'jetpack_full_sync_options', array( true ) );

		// The number of actions enqueued, and next module state (true == done).
		return array( 'finished' => true );
	}

	/**
	 * Retrieve an estimated number of actions that will be enqueued.
	 *
	 * @access public
	 *
	 * @param array $config Full sync configuration for this sync module.
	 * @return int Number of items yet to be enqueued.
	 */
	public function estimate_full_sync_actions( $config ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
		return 1;
	}

	/**
	 * Retrieve the actions that will be sent for this module during a full sync.
	 *
	 * @access public
	 *
	 * @return array Full sync actions of this module.
	 */
	public function get_full_sync_actions() {
		return array( 'jetpack_full_sync_options' );
	}

	/**
	 * Retrieve all options as per the current options whitelist.
	 * Public so that we don't have to store so much data all the options twice.
	 *
	 * @access public
	 *
	 * @return array All options.
	 */
	public function get_all_options() {
		$options       = array();
		$random_string = wp_generate_password();
		foreach ( $this->options_whitelist as $option ) {
			$option_value = get_option( $option, $random_string );
			if ( $option_value !== $random_string ) {
				$options[ $option ] = $option_value;
			}
		}

		// Add theme mods.
		$theme_mods_option = 'theme_mods_' . get_option( 'stylesheet' );
		$theme_mods_value  = get_option( $theme_mods_option, $random_string );
		if ( $theme_mods_value === $random_string ) {
			return $options;
		}
		$this->filter_theme_mods( $theme_mods_value );
		$options[ $theme_mods_option ] = $theme_mods_value;
		return $options;
	}

	/**
	 * Update the options whitelist to the default one.
	 *
	 * @access public
	 */
	public function update_options_whitelist() {
		$this->options_whitelist = Defaults::get_options_whitelist();
	}

	/**
	 * Set the options whitelist.
	 *
	 * @access public
	 *
	 * @param array $options The new options whitelist.
	 */
	public function set_options_whitelist( $options ) {
		$this->options_whitelist = $options;
	}

	/**
	 * Get the options whitelist.
	 *
	 * @access public
	 *
	 * @return array The options whitelist.
	 */
	public function get_options_whitelist() {
		return $this->options_whitelist;
	}

	/**
	 * Update the contentless options to the defaults.
	 *
	 * @access public
	 */
	public function update_options_contentless() {
		$this->options_contentless = Defaults::get_options_contentless();
	}

	/**
	 * Get the contentless options.
	 *
	 * @access public
	 *
	 * @return array Array of the contentless options.
	 */
	public function get_options_contentless() {
		return $this->options_contentless;
	}

	/**
	 * Reject any options that aren't whitelisted or contentless.
	 *
	 * @access public
	 *
	 * @param array $args The hook parameters.
	 * @return array $args The hook parameters.
	 */
	public function whitelist_options( $args ) {
		// Reject non-whitelisted options.
		if ( ! $this->is_whitelisted_option( $args[0] ) ) {
			return false;
		}

		// Filter our weird array( false ) value for theme_mods_*.
		if ( 'theme_mods_' === substr( $args[0], 0, 11 ) ) {
			$this->filter_theme_mods( $args[1] );
			if ( isset( $args[2] ) ) {
				$this->filter_theme_mods( $args[2] );
			}
		}

		// Set value(s) of contentless option to empty string(s).
		if ( $this->is_contentless_option( $args[0] ) ) {
			// Create a new array matching length of $args, containing empty strings.
			$empty    = array_fill( 0, count( $args ), '' );
			$empty[0] = $args[0];
			return $empty;
		}

		return $args;
	}

	/**
	 * Whether a certain option is whitelisted for sync.
	 *
	 * @access public
	 *
	 * @param string $option Option name.
	 * @return boolean Whether the option is whitelisted.
	 */
	public function is_whitelisted_option( $option ) {
		return in_array( $option, $this->options_whitelist, true ) || 'theme_mods_' === substr( $option, 0, 11 );
	}

	/**
	 * Whether a certain option is a contentless one.
	 *
	 * @access private
	 *
	 * @param string $option Option name.
	 * @return boolean Whether the option is contentless.
	 */
	private function is_contentless_option( $option ) {
		return in_array( $option, $this->options_contentless, true );
	}

	/**
	 * Filters out falsy values from theme mod options.
	 *
	 * @access private
	 *
	 * @param array $value Option value.
	 */
	private function filter_theme_mods( &$value ) {
		if ( is_array( $value ) && isset( $value[0] ) ) {
			unset( $value[0] );
		}
	}

	/**
	 * Handle changes in the core site icon and sync them.
	 *
	 * @access public
	 */
	public function jetpack_sync_core_icon() {
		$url = get_site_icon_url();

		require_once JETPACK__PLUGIN_DIR . 'modules/site-icon/site-icon-functions.php';
		// If there's a core icon, maybe update the option.  If not, fall back to Jetpack's.
		if ( ! empty( $url ) && jetpack_site_icon_url() !== $url ) {
			// This is the option that is synced with dotcom.
			\Jetpack_Options::update_option( 'site_icon_url', $url );
		} elseif ( empty( $url ) ) {
			\Jetpack_Options::delete_option( 'site_icon_url' );
		}
	}

	/**
	 * Expand all options within a hook before they are serialized and sent to the server.
	 *
	 * @access public
	 *
	 * @param array $args The hook parameters.
	 * @return array $args The hook parameters.
	 */
	public function expand_options( $args ) {
		if ( $args[0] ) {
			return $this->get_all_options();
		}

		return $args;
	}

	/**
	 * Return Total number of objects.
	 *
	 * @param array $config Full Sync config.
	 *
	 * @return int total
	 */
	public function total( $config ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
		return count( Defaults::get_options_whitelist() );
	}

}