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

namespace EnVisage.Code.Cache
{
	public class CacheManager
	{
		private static CacheManager instance;
		public static CacheManager Instance
		{
			get
			{
				return instance ?? new CacheManager();
			}
		}

		protected CacheManager()
		{ }

		private System.Web.Caching.Cache cache = HttpContext.Current.Cache;

		public void AddToCache(string key, object value)
		{
			if(!IsInCache(key))
				cache.Add(key, value, null, 
						System.Web.Caching.Cache.NoAbsoluteExpiration, TimeSpan.FromMinutes(60), CacheItemPriority.Default, null);
			else
				cache.Insert(key, value);
		}

		public void RemoveFromCache(string key)
		{
			if (cache[key] != null)
				cache.Remove(key);
		}

		public bool IsInCache(string key)
		{
			if (cache.Count == 0)
				return false;
			else
				return cache[key] != null;
		}

		public object GetCacheData(string key)
		{
			if (IsInCache(key))
				return cache[key];
			else
				return null;
		}
	}
}