using Common;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using System.Web.Caching;

namespace KC.Cache.WebCache
{
    public class WebCache:ICache
    {
        protected static volatile System.Web.Caching.Cache webCache = HttpRuntime.Cache;
        private static int timeOut = ConfigHelper.GetValue("OutTime").TryToInt32();
        /// <summary>
        /// 写入缓存，单体
        /// </summary>
        /// <param name="value">对象数据</param>
        /// <param name="cacheKey">键</param>
        /// <param name="seconds">几秒过期</param>
        public void WriteCache<T>(string cacheKey, T value, int seconds = 0) where T : class
        {
            if (String.IsNullOrEmpty(cacheKey) || value == null)
                return;
            if (seconds == 0)
                seconds = timeOut;
            var callBack = new CacheItemRemovedCallback(onRemove);
            webCache.Insert(cacheKey, value, null, System.DateTime.Now.AddSeconds(seconds), System.Web.Caching.Cache.NoSlidingExpiration, CacheItemPriority.High, callBack);
        }





        /// <summary>
        /// 读取缓存，单体
        /// </summary>
        /// <param name="cacheKey">键</param>
        /// <returns></returns>
        public T GetCache<T>(string cacheKey) where T : class
        {
            if (!String.IsNullOrEmpty(cacheKey))
                return (T)webCache.Get(cacheKey);

            return default(T);
        }



        /// <summary>
        ///  获取所有key
        /// </summary>
        /// <returns></returns>
        public List<string> GetAllKeys()
        {
            List<string> list = new List<string>();
            var enu = webCache.GetEnumerator();
            while (enu.MoveNext())
            {
                list.Add(enu.Key.ToString());
            }

            return list;
        }

        /// <summary>
        /// 确定当前Key是否过期
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public bool HasExpire(string cacheKey)
        {
            if (string.IsNullOrEmpty(cacheKey))
                return false;
            return webCache[cacheKey] != null;
        }

        /// <summary>
        /// 移除指定数据缓存
        /// </summary>
        /// <param name="cacheKey">键</param>
        public void RemoveCache(string cacheKey)
        {
            if (!String.IsNullOrEmpty(cacheKey))
                webCache.Remove(cacheKey);
        }

        /// <summary>
        /// 批量删除数据缓存
        /// </summary>
        /// <param name="keys"></param>
        public void RemoveCache(List<string> keys)
        {
            if (keys.Count > 0)
            {
                var enu = webCache.GetEnumerator();
                while (enu.MoveNext())
                {
                    string key = enu.Key.ToString();
                    if (keys.Where(p => p == key).Count() > 0)
                    {
                        RemoveCache(key);
                    }
                }
            }
        }

        #region MyRegion
        public void onRemove(string key, object val, CacheItemRemovedReason reason)
        {
            switch (reason)
            {
                case CacheItemRemovedReason.DependencyChanged:
                    //更新缓存映射表
                    break;
                case CacheItemRemovedReason.Expired:
                    //更新缓存映射表
                    break;
                case CacheItemRemovedReason.Removed:
                    break;
                case CacheItemRemovedReason.Underused:
                    break;
                default:
                    break;
            }
        }
        #endregion
    }
}