PI_Assync_SCDE/Infrastructure/RateLimiter.cs

namespace Infrastructure
{
    public class RateLimiter
    {
        private readonly int _maxRequests;
        private readonly TimeSpan _interval;
        private int _requestCount;
        private DateTime _windowStart;
        private readonly object _lock = new();

        public RateLimiter(int maxRequests, TimeSpan interval)
        {
            _maxRequests = maxRequests;
            _interval = interval;
            var now = DateTime.Now;
            _windowStart = new DateTime(now.Year, now.Month, now.Day, now.Hour, now.Minute - (now.Minute % interval.Minutes), 0);
            _requestCount = 0;
        }

        public async Task WaitAsync(CancellationToken ct)
        {
            while (true)
            {
                lock (_lock)
                {
                    if ((DateTime.Now - _windowStart) > _interval)
                    {
                        // reset janela
                        _windowStart = DateTime.Now;
                        _requestCount = 0;
                    }

                    if (_requestCount < _maxRequests)
                    {
                        _requestCount++;
                        return; // pode prosseguir
                    }
                }

                // já bateu o limite → espera até reset
                await Task.Delay(200, ct); // aguarda 200ms e tenta de novo
            }
        }
    }
}