using PCScreenSavers.ViewModel;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Xml;

namespace PCScreenSavers.Business
{
    class VersionUpdate
    {
        /// <summary>
        /// 是否需要更新
        /// </summary>
        /// <returns></returns>
        public List<XmlNodeItem> IsUpdate(out string currentVersion,string conUpdate)
        {
            List<XmlNodeItem> updateList = new List<XmlNodeItem>();
            try
            {
                string localPath = Directory.GetCurrentDirectory() + "\\ScreenVersion.txt";

                FileStream fs = new FileStream(localPath, FileMode.Open);
                using (StreamReader sr = new StreamReader(fs))
                {
                    string temp = sr.ReadLine();
                    currentVersion = temp.Substring(temp.LastIndexOf("V"));
                }
                //fs.Close();

                List<XmlNodeItem> versionList = XmlReader(conUpdate);

                foreach (var item in versionList)
                {
                    if (currentVersion != item.Title)
                        updateList.Add(item);
                    else
                        break;
                }
                return updateList;
            }
            catch
            {
                currentVersion = "";
                return updateList;
            }
        }

        /// <summary>
        /// 读取xml文件
        /// </summary>
        /// <param name="url"></param>
        /// <returns></returns>
        private List<XmlNodeItem> XmlReader(string url)
        {

            List<XmlNodeItem> nodeList = new List<XmlNodeItem>();
            try
            {
                XmlDocument doc = new XmlDocument();
                doc.Load(url);    //加载Xml文件  
                XmlElement rootElem = doc.DocumentElement;   //获取根节点 
                XmlNodeList itemNodes = rootElem.GetElementsByTagName("item"); //获取item子节点集合  
                foreach (XmlNode node in itemNodes)
                {
                    XmlNodeItem item = new XmlNodeItem();
                    XmlNodeList subTitleNodes = ((XmlElement)node).GetElementsByTagName("title");  //获取title子XmlElement集合  
                    XmlNodeList subDateNodes = ((XmlElement)node).GetElementsByTagName("date");  //获取date子XmlElement集合  
                    XmlNodeList subUrlNodes = ((XmlElement)node).GetElementsByTagName("url");  //获取url子XmlElement集合  
                    XmlNodeList subConfigNodes = ((XmlElement)node).GetElementsByTagName("iscopyconfig");  //获取iscopyconfig子XmlElement集合  
                    XmlNodeList subDescribtionNodes = ((XmlElement)node).GetElementsByTagName("describtion");  //获取describtion子XmlElement集合
                    if (subTitleNodes.Count == 1)
                        item.Title = subTitleNodes[0].InnerText;
                    if (subDateNodes.Count == 1)
                        item.Date = subDateNodes[0].InnerText;
                    if (subUrlNodes.Count == 1)
                        item.Url = subUrlNodes[0].InnerText;
                    if (subConfigNodes.Count == 1)
                        item.IsCopyConfig = subConfigNodes[0].InnerText;
                    if (subDescribtionNodes.Count == 1)
                        item.Describtion = subDescribtionNodes[0].InnerText;

                    nodeList.Add(item);
                }

                return nodeList;
            }
            catch (Exception ex)
            {
                return nodeList;
            }
        }
    }
}