using Microsoft.Extensions.Caching.Memory;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace CrazyStudio.Core.Common
{
    public class CacheManager
    {
        public static CacheManager Default = new CacheManager();

        private IMemoryCache _cache = new MemoryCache(new MemoryCacheOptions());

        /// <summary>
        /// 取得缓存数据
        /// </summary>
        /// <typeparam name="T">类型值</typeparam>
        /// <param name="key">关键字</param>
        /// <returns></returns>
        public T Get<T>(string key)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));
            T value;
            _cache.TryGetValue<T>(key, out value);
            return value;
        }

        /// <summary>
        /// 设置缓存(永不过期)
        /// </summary>
        /// <param name="key">关键字</param>
        /// <param name="value">缓存值</param>
        public void Set_NotExpire<T>(string key, T value)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));

            T v;
            if (_cache.TryGetValue(key, out v))
                _cache.Remove(key);
            _cache.Set(key, value);
        }

        /// <summary>
        /// 设置缓存(滑动过期:超过一段时间不访问就会过期,一直访问就一直不过期)
        /// </summary>
        /// <param name="key">关键字</param>
        /// <param name="value">缓存值</param>
        public void Set_SlidingExpire<T>(string key, T value, TimeSpan span)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));

            T v;
            if (_cache.TryGetValue(key, out v))
                _cache.Remove(key);
            _cache.Set(key, value, new MemoryCacheEntryOptions()
            {
                SlidingExpiration = span
            });
        }

        /// <summary>
        /// 设置缓存(绝对时间过期:从缓存开始持续指定的时间段后就过期,无论有没有持续的访问)
        /// </summary>
        /// <param name="key">关键字</param>
        /// <param name="value">缓存值</param>
        public void Set_AbsoluteExpire<T>(string key, T value, TimeSpan span)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));

            T v;
            if (_cache.TryGetValue(key, out v))
                _cache.Remove(key);
            _cache.Set(key, value, span);
        }

        /// <summary>
        /// 设置缓存(绝对时间过期+滑动过期:比如滑动过期设置半小时,绝对过期时间设置2个小时，那么缓存开始后只要半小时内没有访问就会立马过期,如果半小时内有访问就会向后顺延半小时，但最多只能缓存2个小时)
        /// </summary>
        /// <param name="key">关键字</param>
        /// <param name="value">缓存值</param>
        public void Set_SlidingAndAbsoluteExpire<T>(string key, T value, TimeSpan slidingSpan, TimeSpan absoluteSpan)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));

            T v;
            if (_cache.TryGetValue(key, out v))
                _cache.Remove(key);
            _cache.Set(key, value, new MemoryCacheEntryOptions()
            {
                SlidingExpiration = slidingSpan,
                AbsoluteExpiration = DateTimeOffset.Now.AddMilliseconds(absoluteSpan.TotalMilliseconds)
            });
        }

        /// <summary>
        /// 移除缓存
        /// </summary>
        /// <param name="key">关键字</param>
        public void Remove(string key)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));

            _cache.Remove(key);
        }

        /// <summary>
        /// 释放
        /// </summary>
        public void Dispose()
        {
            if (_cache != null)
                _cache.Dispose();
            GC.SuppressFinalize(this);
        }
    }
}
