le = sprintf( esc_html__( 'Your Security Digest for %s', 'better-wp-security' ), '<b>' . $period . '</b>' );
				break;
		}

		$data_proxy = new ITSEC_Notify_Data_Proxy( $data );

		$mail = $nc->mail( 'digest' );
		$mail->add_header(
			$title,
			$banner_title,
			false,
			sprintf( esc_html__( 'The following is a summary of security related activity on your site: %s', 'better-wp-security' ), '<b>' . $mail->get_display_url() . '</b>' )
		);

		$content = $mail->get_content();

		/**
		 * Fires before the main content of the Security Digest is added.
		 *
		 * @param ITSEC_Mail              $mail
		 * @param ITSEC_Notify_Data_Proxy $data_proxy
		 * @param int                     $last_sent
		 */
		do_action( 'itsec_security_digest_before', $mail, $data_proxy, $last_sent );

		if ( $content !== $mail->get_content() ) {
			$send_email = true;
		}

		$mail->add_section_heading( esc_html__( 'Lockouts', 'better-wp-security' ), 'lock' );

		$user_count = $itsec_lockout->get_lockouts( 'user', array( 'after' => $last_sent, 'current' => false, 'return' => 'count' ) );
		$host_count = $itsec_lockout->get_lockouts( 'host', array( 'after' => $last_sent, 'current' => false, 'return' => 'count' ) );

		if ( $host_count > 0 || $user_count > 0 ) {
			$mail->add_lockouts_summary( $user_count, $host_count );
			$send_email = true;
		} else {
			$mail->add_text( esc_html__( 'No lockouts since the last email check.', 'better-wp-security' ) );
		}

		if ( $data_proxy->has_message( 'file-change' ) ) {
			$mail->add_section_heading( esc_html__( 'File Changes', 'better-wp-security' ), 'folder' );
			$mail->add_text( esc_html__( 'File changes detected on the site.', 'better-wp-security' ) );
			$send_email = true;
		}

		if ( ! $send_email ) {
			$content = $mail->get_content();
		}

		/**
		 * Fires when additional info should be attached to the Security Digest.
		 *
		 * @since 3.9.0
		 *
		 * @param ITSEC_Mail              $mail
		 * @param ITSEC_Notify_Data_Proxy $data_proxy
		 * @param int                     $last_sent
		 */
		do_action( 'itsec_security_digest_attach_additional_info', $mail, $data_proxy, $last_sent );

		if ( ! $send_email && $content !== $mail->get_content() ) {
			$send_email = true;
		}

		$messages = $this->get_general_messages( $data );

		if ( $messages ) {
			$mail->add_section_heading( esc_html__( 'Messages', 'better-wp-security' ), 'message' );

			foreach ( $messages as $message ) {
				$mail->add_text( $message );
			}

			$send_email = true;
		}


		if ( ! $send_email ) {
			return true;
		}


		$mail->add_details_box( sprintf(
			esc_html__( 'For more details, %1$svisit your security logs%2$s', 'better-wp-security' ),
			'<a href="' . ITSEC_Mail::filter_admin_page_url( ITSEC_Core::get_logs_page_url() ) . '"><b>',
			'</b></a>'
		) );

		$mail->add_footer();

		return $nc->send( 'digest', $mail );
	}

	/**
	 * Get general digest messages.
	 *
	 * @param array $data
	 *
	 * @return string[]
	 */
	private function get_general_messages( $data ) {

		$messages = array();

		foreach ( $data as $datum ) {

			if ( ! is_array( $datum ) || ! isset( $datum['message'] ) ) {
				continue;
			}

			if ( isset( $datum['type'] ) && 'general' !== $datum['type'] ) {
				continue;
			}

			$messages[] = $datum['message'];
		}

		return $messages;
	}

	/**
	 * Used by the File Change Detection module to tell the notification system about found file changes.
	 *
	 * @since 2.6.0
	 *
	 * @return null
	 */
	public function register_file_change() {
		_deprecated_function( __METHOD__, '3.9.0', 'ITSEC_Notification_Center::enqueue_data' );
		ITSEC_Core::get_notification_center()->enqueue_data( 'digest', array( 'type' => 'file-change' ) );
	}

	/**
	 * Set HTML content type for email
	 *
	 * @since 4.5
	 *
	 * @return string html content type
	 */
	public function wp_mail_content_type() {

		return 'text/html';

	}
}

class ITSEC_Notify_Data_Proxy {

	/** @var array */
	private $data;

	/**
	 * ITSEC_Notify_Data_Proxy constructor.
	 *
	 * @param array $data
	 */
	public function __construct( $data ) { $this->data = $data; }

	/**
	 * Check for a queued message.
	 *
	 * @param string $type
	 *
	 * @return array|null
	 */
	public function has_message( $type ) {

		foreach ( $this->data as $datum ) {

			if ( ! is_array( $datum ) ) {
				continue;
			}

			if ( isset( $datum['type'] ) && $type === $datum['type'] ) {
				return $datum;
			}
		}

		return null;
	}

	/**
	 * Get all messages of a given type.
	 *
	 * @param string $type
	 *
	 *' @return array
	 */
	public function get_messages_of_type( $type ) {

		$of_type = array();

		foreach ( $this->data as $datum ) {
			if ( ! is_array( $datum ) ) {
				continue;
			}

			if ( isset( $datum['type'] ) && $type === $datum['type'] ) {
				$of_type[] = $datum;
			}
		}

		return $of_type;
	}

}