// ==========================================================================
//  Squidex Headless CMS
// ==========================================================================
//  Copyright (c) Squidex UG (haftungsbeschränkt)
//  All rights reserved. Licensed under the MIT license.
// ==========================================================================

using System;
using System.Collections.Generic;
using NodaTime;

namespace Squidex.Infrastructure
{
    public sealed class RetryWindow
    {
        private readonly Duration windowDuration;
        private readonly int windowSize;
        private readonly Queue<Instant> retries = new Queue<Instant>();
        private readonly IClock clock;

        public RetryWindow(TimeSpan windowDuration, int windowSize, IClock clock = null)
        {
            this.windowDuration = Duration.FromTimeSpan(windowDuration);
            this.windowSize = windowSize + 1;

            this.clock = clock ?? SystemClock.Instance;
        }

        public void Reset()
        {
            retries.Clear();
        }

        public bool CanRetryAfterFailure()
        {
            var now = clock.GetCurrentInstant();

            retries.Enqueue(now);

            while (retries.Count > windowSize)
            {
                retries.Dequeue();
            }

            return retries.Count < windowSize || (retries.Count > 0 && (now - retries.Peek()) > windowDuration);
        }
    }
}