using System;

using Microsoft.Extensions.Caching.Memory;

using System.Runtime;

namespace UFX.Tools

{

    public class CacheHelper

    {

        public static IMemoryCache _memoryCache= new MemoryCache(new MemoryCacheOptions());

        /// <summary>

        /// 缓存绝对过期时间

        /// </summary>

        ///<param name="key">Cache键值</param>

        ///<param name="value">给Cache[key]赋的值</param>

        ///<param name="minute">minute分钟后绝对过期</param>

        public static void CacheInsertAddMinutes(string key, object value, int minute)

        {

            if (value == null) return;

            _memoryCache.Set(key, value, new MemoryCacheEntryOptions()

                    .SetAbsoluteExpiration(TimeSpan.FromMinutes(minute)));

        }

        /// <summary>

        /// 缓存相对过期，最后一次访问后minute分钟后过期

        /// </summary>

        ///<param name="key">Cache键值</param>

        ///<param name="value">给Cache[key]赋的值</param>

        ///<param name="minute">滑动过期分钟</param>

        public static void CacheInsertFromMinutes(string key, object value, int minute)

        {

            if (value == null) return;

            _memoryCache.Set(key, value, new MemoryCacheEntryOptions()

                    .SetSlidingExpiration(TimeSpan.FromMinutes(minute)));

        }

        /// <summary>

        ///以key键值，把value赋给Cache[key].如果不主动清空，会一直保存在内存中.

        /// </summary>

        ///<param name="key">Cache键值</param>

        ///<param name="value">给Cache[key]赋的值</param>

        public static void CacheInsert(string key, object value)

        {

            _memoryCache.Set(key, value);

        }

        /// <summary>

        ///清除Cache[key]的值

        /// </summary>

        ///<param name="key"></param>

        public static void CacheNull(string key)

        {

            _memoryCache.Remove(key);

        }

        /// <summary>

        ///根据key值，返回Cache[key]的值

        /// </summary>

        ///<param name="key"></param>

        public static object CacheValue(string key)

        {

            return _memoryCache.Get(key);

        }

        #region 缓存文档

        //public IActionResult Index()

        //{

        //    string cacheKey = "key";

        //    string result;

        //    if (!_memoryCache.TryGetValue(cacheKey, out result))

        //    {

        //        result = $"LineZero{DateTime.Now}";

        //        _memoryCache.Set(cacheKey, result);

        //        //设置相对过期时间2分钟

        //        _memoryCache.Set(cacheKey, result, new MemoryCacheEntryOptions()

        //            .SetSlidingExpiration(TimeSpan.FromMinutes(2)));

        //        //设置绝对过期时间2分钟

        //        _memoryCache.Set(cacheKey, result, new MemoryCacheEntryOptions()

        //            .SetAbsoluteExpiration(TimeSpan.FromMinutes(2)));

        //        //移除缓存

        //        _memoryCache.Remove(cacheKey);

        //        //缓存优先级 （程序压力大时，会根据优先级自动回收）

        //        _memoryCache.Set(cacheKey, result, new MemoryCacheEntryOptions()

        //            .SetPriority(CacheItemPriority.NeverRemove));

        //        //缓存回调 10秒过期会回调

        //        _memoryCache.Set(cacheKey, result, new MemoryCacheEntryOptions()

        //            .SetAbsoluteExpiration(TimeSpan.FromSeconds(10))

        //            .RegisterPostEvictionCallback((key, value, reason, substate) =>

        //            {

        //                Console.WriteLine($"键{key}值{value}改变，因为{reason}");

        //            }));

        //        //缓存回调 根据Token过期

        //        var cts = new CancellationTokenSource();

        //        _memoryCache.Set(cacheKey, result, new MemoryCacheEntryOptions()

        //            .AddExpirationToken(new CancellationChangeToken(cts.Token))

        //            .RegisterPostEvictionCallback((key, value, reason, substate) =>

        //            {

        //                Console.WriteLine($"键{key}值{value}改变，因为{reason}");

        //            }));

        //        cts.Cancel();

        //    }

        //    ViewBag.Cache = result;

        //    return View();

        //}

        #endregion

    }

}