public class RateLimitMiddleware

    {

        private readonly RequestDelegate _next;

        private readonly ILogger<RateLimitMiddleware> _logger;

        private readonly ConcurrentDictionary<string, DateTime> _requestDictionary;

​

        public RateLimitMiddleware(RequestDelegate next, ILogger<RateLimitMiddleware> logger)

        {

            _next = next;

            _logger = logger;

            _requestDictionary = new ConcurrentDictionary<string, DateTime>();

        }

​

        public async Task InvokeAsync(HttpContext context)

        {

            var ipAddress = context.Connection.RemoteIpAddress?.ToString();

            var currentTime = DateTime.UtcNow;

​

            if (IsRateLimitExceeded(ipAddress, currentTime))

            {

                _logger.LogInformation($"Rate limit exceeded for IP address: {ipAddress}");

                context.Response.StatusCode = StatusCodes.Status429TooManyRequests;

                await context.Response.WriteAsync("Too many requests. Please try again later.");

                return;

            }

​

            await _next(context);

​

            _requestDictionary.AddOrUpdate(ipAddress, currentTime, (_, _) => currentTime);

        }

​

        private bool IsRateLimitExceeded(string ipAddress, DateTime currentTime)

        {

            if (_requestDictionary.TryGetValue(ipAddress, out var lastRequestTime))

            {

                var timeDifference = currentTime - lastRequestTime;

                return timeDifference.TotalSeconds < 10; // Ограничение в 10 секунд

            }

​

            return false;

        }

    }