Requirement-
The requirement is to send notifications to devices on specific times. That is, if a user has setup a schedule at 07:00 AM for breakfast, he'll get a notification for the same like 'Its time for breakfast, blah blah blah!'.
However, if the user has already had his breakfast before 07:00 AM, he'll make his diary entry on what he had etc. and then the notification must not be sent to him.
This is a recurring schedule and the user will only change this if he needs to, otherwise, the schedule will mostly be the same.
What we have achieved?-
So, for now what we do is to register devices with tags like '{TimeZone:EST},{Breakfast:07:00:00}' on the app's launch.
In case, the user has already had his breakfast, we update his registration on notification hub to also contain a tag like '{HadBreakfast}' - So, the set of tags user's device is registered to becomes - '{TimeZone:EST},{Breakfast:07:00:00},{HadBreakfast}'
What are we stuck at?-
This approach will work very well because, when sending notifications, we use tag expression like - '{TimeZone:EST} && {Breakfast:07:00:00} && !{HadBreakfast}'
So, this will send a notification to all users that wants a notification for breakfast at 07:00:00 AM for EST timezone but not to the ones who already had their breakfast.
However, if the user is registered with a tag like {HadBreakfast}, then the next day, he might not get the notification based on the logic just described.
So, we came up with the workaround to de-register only the {HadBreakfast} tag at the end of day for all the devices which has that tag by running a scheduler.
But, somewhere in our mind, we think that is not the best solution for this problem.
Other Alternative-
We also thought of another alternative that we can run a scheduler for every hour within which, it will do the same thing of removing such tags for the past hour for all the user devices which has that tag - and this process seems to be effective than running it once in a day.
But we wanted to know thoughts from the community on what I can try out? If the method that we use is correct or not? What else could be done to do this more simply OR smoothly? What if we have a million plus devices? Will this work?
