PeriodicTimer: .NET 6

namespace PeriodicTimerDemo;

// REF
// https://www.youtube.com/watch?v=J4JL4zR_l-0

public class BackgroundTask
{
    private readonly PeriodicTimer _periodicTimer;
    private Task _task;

    // TaskCompletionSource : learn more in SingletonSean
    // private CancellationToken _cancellationToken = new();
    private readonly CancellationTokenSource _cancellationTokenSource = new();

    public BackgroundTask(TimeSpan timeSpan)
    {
        _periodicTimer = new PeriodicTimer(timeSpan);
    }

    public void Start() => _task = WorkAsync();

    private async Task WorkAsync()
    {
        try
        {
            while (await _periodicTimer.WaitForNextTickAsync(_cancellationTokenSource.Token))
            {
                // Console.WriteLine("Ta-da!");
                Console.WriteLine(DateTime.Now.ToString("O"));
            }
        }
        catch (OperationCanceledException exception)
        {
            // user cancel using StopAsync which uses CancellationTokenSource
        }
    }

    public async Task StopAsync()
    {
        if (_task is null)
        {
            return;
        }

        _cancellationTokenSource.Cancel();
        await _task;
        _cancellationTokenSource.Dispose();
    }
}