using Microsoft.Practices.EnterpriseLibrary.Caching;
using Microsoft.Practices.EnterpriseLibrary.Caching.Expirations;
using System;

namespace ETLUtilHelpV2
{
  /// <summary>
  /// Enterprise Library for .NET Framework 2.0 緩存工具類
  /// </summary>
  public class ETLCacheToolV2
  {
    /*
     *在Caching Application Block中，主要提供以下四種保存緩存數(shù)據(jù)的途徑，
     *分別是：內(nèi)存存儲（默認(rèn)）、獨立存儲（Isolated Storage）、
     *數(shù)據(jù)庫存儲（DataBase Cache Storage）和自定義存儲（Custom Cache Storage）。
     *In-Memory：保存在內(nèi)存中。  
     *Isolated Storage Cache Store：系統(tǒng)將緩存的信息保存在獨立文件中（C:\Users\<<user name>>\AppData\Local\IsolatedStorage）。
     *Data Cache Storage：將緩存數(shù)據(jù)保存在數(shù)據(jù)庫中。（需要運行CreateCachingDatabase.sql腳本）
     *Custom Cache Storage：自己擴展的處理器。我們可以將數(shù)據(jù)保存在注冊表中或文本文件中。
     *
     * 緩存等級，在企業(yè)庫的緩存模塊中已經(jīng)提供了4個緩存等級：Low，Normal，High和NotRemovable，在超出最大緩存數(shù)量后會自動根據(jù)緩存等級來移除對象。
     * 過期方式，企業(yè)庫默認(rèn)提供4種過期方式
     * AbsoluteTime：絕對是時間過期，傳遞一個時間對象指定到時過期
     * SlidingTime：緩存在最后一次訪問之后多少時間后過期，默認(rèn)為2分鐘，有2個構(gòu)造函數(shù)可以指定一個過期時間或指定一個過期時間和一個最后使用時
     * ExtendedFormatTime ：指定過期格式，以特定的格式來過期，通過ExtendedFormat.cs類來包裝過期方式，具體可參照ExtendedFormat.cs，源代碼中已經(jīng)給出了很多方式
     * FileDependency：依賴于文件過期，當(dāng)所依賴的文件被修改則過期，這個我覺得很有用，因為在許多網(wǎng)站，如論壇、新聞系統(tǒng)等都需要大量的配置，可以將配置文件信息進行緩存，將依賴項設(shè)為配置文件，這樣當(dāng)用戶更改了配置文件后通過ICacheItemRefreshAction.Refresh可以自動重新緩存。
     */

    ///// <summary>
    ///// 自定義緩存刷新操作
    ///// </summary>
    //[Serializable]
    //public class CacheItemRefreshAction : ICacheItemRefreshAction
    //{
    //  #region ICacheItemRefreshAction 成員
    //  /// <summary>
    //  /// 自定義刷新操作
    //  /// </summary>
    //  /// <param name="removedKey">移除的鍵</param>
    //  /// <param name="expiredValue">過期的值</param>
    //  /// <param name="removalReason">移除理由</param>
    //  void ICacheItemRefreshAction.Refresh(string removedKey, object expiredValue, CacheItemRemovedReason removalReason)
    //  {
    //    if (removalReason == CacheItemRemovedReason.Expired)
    //    {
    //      CacheManager cache = CacheFactory.GetCacheManager();
    //      cache.Add(removedKey, expiredValue);
    //    }
    //  }
    //  #endregion
    //}

    static CacheManager CacheMgr = null;
    static ETLCacheToolV2()
    {
      CacheMgr = CacheFactory.GetCacheManager();
    }
    /// <summary>
    /// 獲取CacheManager實例
    /// </summary>
    /// <returns>CacheManager</returns>
    public static CacheManager Instance()
    {
      return CacheMgr;
    }
    /// <summary>
    /// 添加緩存
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    public static void Add(string key, object value)
    {
      CacheMgr.Add(key, value);
    }
    /// <summary>
    /// 添加緩存_滑動過期_小時
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="hour">小時</param>
    public static void AddWithHour(string key, object value, int hour)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, null, new SlidingTime(TimeSpan.FromHours(hour)));
    }
    /// <summary>
    /// 添加緩存_滑動過期_天
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="days">天</param>
    public static void AddWithDay(string key, object value, int days)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, null, new SlidingTime(TimeSpan.FromDays(days)));
    }
    /// <summary>
    /// 添加緩存_滑動過期_毫秒
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="millisecond">毫秒</param>
    public static void AddWithMillisecond(string key, object value, int millisecond)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, null, new SlidingTime(TimeSpan.FromMilliseconds(millisecond)));
    }
    /// <summary>
    ///添加緩存_滑動過期_分鐘
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="minutes">分鐘</param>
    public static void AddWithMinutes(string key, object value, int minutes)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, null, new SlidingTime(TimeSpan.FromMinutes(minutes)));
    }
    /// <summary>
    ///添加緩存_滑動過期_秒
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="seconds">秒</param>
    public static void AddWithSeconds(string key, object value, int seconds)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, null, new SlidingTime(TimeSpan.FromSeconds(seconds)));
    }
    /// <summary>
    /// 添加緩存_滑動過期_文件依賴
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="filePath">文件路徑</param>
    public static void AddFileDependency(string key, object value, string filePath)
    {
      FileDependency _fileDependency = new FileDependency(filePath);
      CacheMgr.Add(key, value, CacheItemPriority.Normal, null, _fileDependency);
    }
    /// <summary>
    /// 添加緩存_滑動過期_小時
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="hour">小時</param>
    /// <param name="refreshAction">ICacheItemRefreshAction</param>
    public static void AddWithHour(string key, object value, int hour, ICacheItemRefreshAction refreshAction)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, refreshAction, new SlidingTime(TimeSpan.FromHours(hour)));
    }
    /// <summary>
    /// 添加緩存_滑動過期_天
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="days">天</param>
    /// <param name="refreshAction">ICacheItemRefreshAction</param>
    public static void AddWithDay(string key, object value, int days, ICacheItemRefreshAction refreshAction)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, refreshAction, new SlidingTime(TimeSpan.FromDays(days)));
    }
    /// <summary>
    /// 添加緩存_滑動過期_毫秒
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="millisecond">毫秒</param>
    /// <param name="refreshAction">ICacheItemRefreshAction</param>
    public static void AddWithMillisecond(string key, object value, int millisecond, ICacheItemRefreshAction refreshAction)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, refreshAction, new SlidingTime(TimeSpan.FromMilliseconds(millisecond)));
    }
    /// <summary>
    /// 添加緩存_滑動過期_分鐘
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="minutes">分鐘</param>
    /// <param name="refreshAction">ICacheItemRefreshAction</param>
    public static void AddWithMinutes(string key, object value, int minutes, ICacheItemRefreshAction refreshAction)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, refreshAction, new SlidingTime(TimeSpan.FromMinutes(minutes)));
    }
    /// <summary>
    /// 添加緩存_滑動過期_秒
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="seconds">秒</param>
    /// <param name="refreshAction">ICacheItemRefreshAction</param>
    public static void AddWithSeconds(string key, object value, int seconds, ICacheItemRefreshAction refreshAction)
    {
      CacheMgr.Add(key, value, CacheItemPriority.Normal, refreshAction, new SlidingTime(TimeSpan.FromSeconds(seconds)));
    }
    /// <summary>
    /// 添加緩存_滑動過期_文件依賴
    /// </summary>
    /// <param name="key">鍵</param>
    /// <param name="value">值</param>
    /// <param name="filePath">文件路徑</param>
    /// <param name="refreshAction">ICacheItemRefreshAction</param>
    public static void AddFileDependency(string key, object value, string filePath, ICacheItemRefreshAction refreshAction)
    {
      FileDependency _fileDependency = new FileDependency(filePath);
      CacheMgr.Add(key, value, CacheItemPriority.Normal, refreshAction, _fileDependency);
    }
    /// <summary>
    /// 清空緩存
    /// </summary>
    public static void Flush()
    {
      CacheMgr.Flush();
    }
    /// <summary>
    /// 移出緩存
    /// </summary>
    /// <param name="key"></param>
    public static void Remove(string key)
    {
      if (CacheMgr.Contains(key))
        CacheMgr.Remove(key);
    }
    /// <summary>
    /// 獲取緩存
    /// </summary>
    /// <param name="key">鍵</param>
    /// <returns>值</returns>
    public static object GetData(string key)
    {
      if (CacheMgr.Contains(key))
        return CacheMgr.GetData(key);
      return null;
    }
    /// <summary>
    /// 獲取緩存
    /// </summary>
    /// <typeparam name="T">泛型</typeparam>
    /// <param name="key">鍵</param>
    /// <returns>值</returns>
    public static T GetData<T>(string key)
    {
      if (CacheMgr.Contains(key))
        return (T)CacheMgr.GetData(key);
      return default(T);
    }
  }
}