اضافه کردن Expiration time به دیتابیس مونگو در Asp.Net Core

public class UserMongoDbRepository : IUserRepository
{
    private readonly IMongoCollection<User> _userCollection;
    private readonly ILogger<UserMongoDbRepository> _logger;

    public UserMongoDbRepository(ILogger<UserMongoDbRepository> logger, IOptions<MongoDbConfiguration> options)
    {
        _logger = logger; 
        var mongoClient = new MongoClient(options.Value.ConnectionString);
        var database = mongoClient.GetDatabase(options.Value.DatabaseName);
        _userCollection = database.GetCollection<User>(options.Value.CollectionName);
    }
 
    public async Task AddUser(User user, CancellationToken cancellationToken)
    {
        await _userCollection.InsertOneAsync(user, null, cancellationToken);
    }
    public async Task<User> GetUserById(int id, CancellationToken cancellationToken)
    {
        var filter = Builders<User>.Filter.Eq(a => a.Id, id);

        var result = await _userCollection.FindAsync(filter, cancellationToken: cancellationToken);

        return await result.FirstOrDefaultAsync(cancellationToken);
    }
}

private void CreateExpireIndex(MongoDbConfiguration mongoDbConfiguration)
{
    var isValidExpireFormat = TimeSpan.TryParseExact(mongoDbConfiguration.ExpireAfter,
        mongoDbConfiguration.ExpireFormat,
        CultureInfo.InvariantCulture,
        out TimeSpan expireAfter);

    if (isValidExpireFormat)
    {
        const string _expireAt = "ExpireAt";
        var expireIndex = new IndexKeysDefinitionBuilder<User>().Ascending(c => c.CreationTime);

        var index = _userCollection.Indexes.List().ToList()
            .Where(a => a["name"] == _expireAt)
            .Select(a => new
            {
                ExpireAfterSeconds = a.GetElement("expireAfterSeconds").Value.ToString()
            }).FirstOrDefault();

        if (index != null)
        {
            var registeredExpireAfter = TimeSpan.FromSeconds(Convert.ToInt64(index.ExpireAfterSeconds));
            if (registeredExpireAfter == expireAfter)
            {
                return;
            }
            _userCollection.Indexes.DropOne(_expireAt);
            _logger.LogInformation($"Index deleted. {registeredExpireAfter.ToString(mongoDbConfiguration.ExpireFormat)}");
        }

        _userCollection.Indexes.CreateOne(new CreateIndexModel<User>(expireIndex, new CreateIndexOptions
        {
            Name = _expireAt,
            ExpireAfter = expireAfter
        }));
        _logger.LogInformation($"Index created. {expireAfter.ToString(mongoDbConfiguration.ExpireFormat)}");
    }
}

public UserMongoDbRepository(ILogger<UserMongoDbRepository> logger, IOptions<MongoDbConfiguration> options)
{
    _logger = logger; 
    var mongoClient = new MongoClient(options.Value.ConnectionString);
    var database = mongoClient.GetDatabase(options.Value.DatabaseName);
    _userCollection = database.GetCollection<User>(options.Value.CollectionName);
    CreateExpireIndex(options.Value);
}

public void ConfigureServices(IServiceCollection services)
{
    services.Configure<MongoDbConfiguration>(a => Configuration.GetSection(nameof(MongoDbConfiguration)).Bind(a));
    services.AddControllers();
    services.AddSingleton<IUserRepository, UserMongoDbRepository>();
}

public class MongoDbConfiguration
{
    public string DatabaseName { get; set; }
    public string ConnectionString { get; set; }
    public string CollectionName { get; set; }
    public string ExpireAfter { get; set; }
    public string ExpireFormat { get; set; }
}

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft": "Warning",
      "Microsoft.Hosting.Lifetime": "Information"
    }
  },
  "AllowedHosts": "*",
  "MongoDbConfiguration": {
    "ConnectionString": "connectionString",
    "DatabaseName": "TestDb",
    "CollectionName": "User",
    "ExpireFormat": "dd':'hh':'mm':'ss",
    "ExpireAfter": "02:00:00:00"
  }
}