using System;
using System.Web;
using System.Web.Caching;

namespace EnVisage.Code.Cache
{
    public class CacheManager
    {
        private static CacheManager instance;
        public static CacheManager Instance
        {
            get
            {
                if (instance == null)
                    instance = new CacheManager();

                return instance;
            }
        }

        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;
        }
    }
}