Changing property after specific time in ASP Core MVC - asp.net

Question

I'm working on a subscription-based system developed using Asp Core 3 MVC and Sql Server. The payment is handled externally, not linked to the application in any way. All I need to do in the application is to check the user's status, that is managed by an admin. When a user registers the status will be Pending, when the admin approves the user, Approval Date will be saved in the database, and the status will be changed to Approved.
The tricky thing for me is that I want the application to wait for 365 days before it changes the user status to Expired. I've no idea from where to start this part and would appreciate your help.

Answer 1

The simplest way i can think of without using hosted services is to add a check on user login that subtracts the approval date from today's date and check if the difference is equal or greater than 365 days
Something like this:
if ((DateTime.Now - user.ApprovalDate).TotalDays >= 365)
{
//Mark the user as expired...
}

Answer 2

You really shouldn't trigger a background thread from your main application code.
The correct way to do this is with a background worker process that has been designed specifically for this scenario.
ASP.NET Core 3 has a project type that is specifically for this, and will continue to run the back ground and can be used for all of your maintenance tasks. You can create a worker process using dotnet new worker -o YourProjectName or selecting Worker Service from the project selection window in Visual Studio.
Within that service you can then create a routine that will be used to determine if the user has expired. Encapsulate this logic in a class that makes testing easy.
Working repl has been posted here.
using System;
public class MainClass {
public static void Main (string[] args) {
var user = new User(){ ApprovedDate = DateTime.Today };
Console.WriteLine (UserHelper.IsUserExpired(user));
// this should be false
user = new User(){ ApprovedDate = DateTime.Today.AddDays(-180) };
Console.WriteLine (UserHelper.IsUserExpired(user));
// this should be false
user = new User(){ ApprovedDate = DateTime.Today.AddDays(-365) };
Console.WriteLine (UserHelper.IsUserExpired(user));
// this should be true
user = new User(){ ApprovedDate = DateTime.Today.AddDays(-366) };
Console.WriteLine (UserHelper.IsUserExpired(user));
}
}
public class User {
public DateTime ApprovedDate {get; set;}
}
public static class UserHelper
{
public static bool IsUserExpired(User user){
//... add all the repective logic in here that you need, for example;
return (DateTime.Today - user.ApprovedDate.Date).TotalDays > 365;
}
}