using System;
using System.Collections.Generic;
using System.Web;
using System.Web.Caching;

namespace CP.Cache
{
	public class BaseCache
    {
		protected static volatile System.Web.Caching.Cache cache = HttpRuntime.Cache;
        
		/// <summary>
		/// cache是否存在
		/// </summary>
		/// <param name="k"></param>
		/// <returns></returns>
		public static bool IsExist(string k)
		{
			if (string.IsNullOrEmpty(k))
				return false;
			return cache[k] != null;
		}
		/// <summary>
		/// 获取cache
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="k"></param>
		/// <returns></returns>
		public static T Get<T>(string k)
		{
			if (!string.IsNullOrEmpty(k) && cache[k] != null)
			{
				return (T)cache.Get(k);
			}
			return default(T);
		}
		/// <summary>
		/// 添加cache
		/// </summary>
		/// <typeparam name="T"></typeparam>
		/// <param name="k">key</param>
		/// <param name="v">value</param>
		/// <param name="m">绝对过期时间</param>
		public static void Add<T>(string k,T v,int m = 0)
		{
			if(!string.IsNullOrEmpty(k) && v != null)
			{
				if (m > 0)
				{
					cache.Insert(k, v, null, DateTime.Now.AddMinutes(m), System.Web.Caching.Cache.NoSlidingExpiration);
				}
				else
				{
					cache.Insert(k, v);
				}
			}
		}
		/// <summary>
		/// 移出Cache
		/// </summary>
		/// <param name="k"></param>
		public static void Remove(string k)
		{
			if(IsExist(k))
			{
				cache.Remove(k);
			}
		}
		/// <summary>
		/// 批量移出cache
		/// </summary>
		/// <param name="k"></param>
		public static void RemoveList(string k)
		{
			if (!string.IsNullOrEmpty(k))
			{
				var e = cache.GetEnumerator();
				while (e.MoveNext())
				{
					if (e.Key.ToString().IndexOf(k, StringComparison.OrdinalIgnoreCase) != -1)
					{
						Remove(e.Key.ToString());
					}
				}
			}
		}
		/// <summary>
		/// 移出所有Cache
		/// </summary>
		public static void RemoveAll()
		{
			var e = cache.GetEnumerator();
			while (e.MoveNext())
			{
				Remove(e.Key.ToString());
			}
		}
		/// <summary>
		/// 获取所有key
		/// </summary>
		/// <returns></returns>
		public static List<string> GetKeys()
		{
			List<string> list = new List<string>();
			var e = cache.GetEnumerator();
			while (e.MoveNext())
			{
				list.Add(e.Key.ToString());
			}
			return list;
		}
		/// <summary>
		/// cache总数
		/// </summary>
		/// <returns></returns>
		public static int Count()
		{
			return cache.Count;
		}
	}
}