// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
 
namespace Microsoft.Extensions.Caching.Distributed
{
    /// <summary>
    /// Provides the cache options for an entry in <see cref="IDistributedCache"/>.
    /// </summary>
    public class DistributedCacheEntryOptions
    {
        private DateTimeOffset? _absoluteExpiration;
        private TimeSpan? _absoluteExpirationRelativeToNow;
        private TimeSpan? _slidingExpiration;
 
        /// <summary>
        /// Gets or sets an absolute expiration date for the cache entry.
        /// </summary>
        public DateTimeOffset? AbsoluteExpiration
        {
            get
            {
                return _absoluteExpiration;
            }
            set
            {
                _absoluteExpiration = value;
            }
        }
 
        /// <summary>
        /// Gets or sets an absolute expiration time, relative to now.
        /// </summary>
        public TimeSpan? AbsoluteExpirationRelativeToNow
        {
            get
            {
                return _absoluteExpirationRelativeToNow;
            }
            set
            {
                if (value <= TimeSpan.Zero)
                {
                    throw new ArgumentOutOfRangeException(
                        nameof(AbsoluteExpirationRelativeToNow),
                        value,
                        "The relative expiration value must be positive.");
                }
 
                _absoluteExpirationRelativeToNow = value;
            }
        }
 
        /// <summary>
        /// Gets or sets how long a cache entry can be inactive (for example, not accessed) before it will be removed.
        /// This will not extend the entry lifetime beyond the absolute expiration (if set).
        /// </summary>
        public TimeSpan? SlidingExpiration
        {
            get
            {
                return _slidingExpiration;
            }
            set
            {
                if (value <= TimeSpan.Zero)
                {
                    throw new ArgumentOutOfRangeException(
                        nameof(SlidingExpiration),
                        value,
                        "The sliding expiration value must be positive.");
                }
                _slidingExpiration = value;
            }
        }
    }
}