using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Text;
using System.Threading;
using System.Web;
using CB.Config;

namespace CB.Cache.WebCache
{
    /// <summary>
    /// 同步缓存类
    /// </summary>
    public class SyncCache
    {
        /// <summary>
        /// 除本站之外的负载均衡站点列表
        /// </summary>
        static List<string> syncCacheUrlList = null;

        static BaseConfigInfo baseConfigInfo = BaseConfigs.GetConfig();

        static SyncCache()
        {
            syncCacheUrlList = new List<string>();
            if (string.IsNullOrEmpty(baseConfigInfo.SyncCacheServer))
            { return; }
            syncCacheUrlList.AddRange(baseConfigInfo.SyncCacheServer.Split(','));
        }

        /// <summary>
        /// 同步远程缓存信息
        /// </summary>
        /// <param name="cacheKey"></param>
        public static void SyncRemoteCache(string cacheKey)
        {
            foreach (string webSite in syncCacheUrlList)
            {
                var src = new ThreadSyncRemoteCache(string.Format("{0}?cacheKey={1}&passKey={2}",
                   webSite, cacheKey, HttpUtility.UrlEncode(CB.Common.XXTEA.Encode(cacheKey))));

                new Thread(new ThreadStart(src.Send)).Start();
            }
        }
    }

    /// <summary>
    /// 多线程更新远程缓存
    /// </summary>
    public class ThreadSyncRemoteCache
    {
        public string _url { get; set; }

        public ThreadSyncRemoteCache(string url)
        {
            _url = url;
        }

        public void Send()
        {
            try
            {
                //设置循环三次，如果某一次更新成功("OK")，则跳出循环
                for (int count = 0; count < 3; count++)
                {
                    if (this.SendWebRequest() == "OK")
                        break;
                    else
                        Thread.Sleep(5000);//如果更新不成功，则暂停5秒后再次更新
                }
            }
            catch { }
            finally
            {
                if (Thread.CurrentThread.IsAlive)
                    Thread.CurrentThread.Abort();
            }
        }

        /// <summary>
        /// 发送web请求
        /// </summary>
        /// <param name="url"></param>
        /// <returns></returns>
        public string SendWebRequest()
        {
            var builder = new StringBuilder();
            try
            {
                WebRequest request = WebRequest.Create(new Uri(_url));
                request.Method = "GET";
                request.Timeout = 10000;
                request.ContentType = "Text/XML";
                using (WebResponse response = request.GetResponse())
                {
                    using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8))
                    {
                        builder.Append(reader.ReadToEnd());
                    }
                }
            }
            catch
            {
                builder.Append("Process Failed!");
            }
            return builder.ToString();
        }
    }
}