Notification Processing Rewrite

gistfile1.txt

        /// <summary>
        /// Attempt to process the RabbitMQ message for the subscriber notification
        /// </summary>
        /// <param name="message"></param>
        /// <param name="retryCount"></param>
        /// <returns></returns>
        private IoEither<Failure, Unit> ProcessMessage(IConsumeContext<ProcessSubscriberNotification> message, int retryCount)
        {
            Func<IConsumeContext<ProcessSubscriberNotification>, string, int, IoEither<Failure, Unit>> delayMessageProcessing = (m, log, delay) =>
                from _0 in Logger.DebugU($"STI Subscriber Notification Handler: {log}. Will retry after a delay of {delay} milliseconds.").ToIoEither<Failure, Unit>()
                from _1 in m.DelayProcessing(delay).ToMaybe().AsEither<Failure, Unit>(() => new GenericFailure($"Failed to delay message[{m.AsReadableObject()}]")).ToIoEither()
                select Unit.Only;
            return
                from id in message.ToMaybe().SelectMany(m => m.Message.ToMaybe()).Select(m => m.NotificationId).AsEither<Failure, int>(() => new GenericFailure($"Unable to process message[{message.AsReadableObject()}]")).ToIoEither()
                from notification in Io.Apply(() => _dataContext.Set<SubscriberNotification>().Find(id).ToMaybe().AsEither<Failure, SubscriberNotification>(() => new GenericFailure($"Unable to get notification[{id}] for message."))).ToIoEither()
                let delay = new TimeSpan(0, 0, (int)ProcessDelay, 0, retryCount * RetryDelay)
                let timeSinceReceived = DateTime.Now.Subtract(notification.Created)
                from _0 in timeSinceReceived.TotalMinutes < ProcessDelay
                    ? delayMessageProcessing(message, $"Delaying processing of subscriber notification[{id}]", RetryDelay * (int)ProcessDelay / (timeSinceReceived.Minutes + 1))
                    : retryCount > 0 && timeSinceReceived < delay
                        ? delayMessageProcessing(message, $"Failed to process subscriber notification[{id}] {retryCount} times", delay.Milliseconds)
                        : ProcessNotification(notification) // TODO - Do something here on failure or success using the notification
                select Unit.Only;
        }

        /// <summary>
        /// Process the given subscriber notification request
        /// </summary>
        /// <param name="notification"></param>
        private IoEither<Failure, Unit> ProcessNotification(SubscriberNotification notification)
        {
            //attempt to match the notification and account
            return Io.Apply(() => notification.Account.ToMaybe().Match(
                //if successful, process the notification
                just: a => ProcessNotificationForAccount(notification, a),
                //if not successfule, see if we can find it
                nothing: () => Try.Attempt(() => _dataContext.Set<SystemUserAccount>().AsQueryable().GetSystemUserAccount(notification.SubscriberNumber, notification.AccountNumber)).Match(
                    //if we found it, process the notification
                    success: a => SaveAccountToNotificationAndProcess(notification, a),
                    //if not we can check to see if it's a holding account
                    failure: ex => GetHoldingAccount(notification.SubscriberNumber, notification.AccountNumber).ToMaybe().Match(
                        //if it is, we shouldn't process it but we can simply log that it was found
                        just: a => Logger.InfoU($"STI Subscriber Notification received a notification[{notification.Id}] for a subscription/holding account with subscriber number {notification.SubscriberNumber} and account number {notification.AccountNumber}. Notification skipped.").UnsafePerformIo().AsRight<Failure, Unit>(),
                        //if we can't find it at all, log and throw exception
                        nothing: () =>
                        {
                            Logger.Warn($"STI Subscriber Notification received a notification[{notification.Id}] for an invalid subscription with subscriber number {notification.SubscriberNumber} and account number {notification.AccountNumber}.");
                            return new GenericFailure("Unable to find an account for the given subscriber notification.").AsLeft<Failure, Unit>();
                        })))).ToIoEither();
        }