using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace AutoUpdater
{
    public class ExceptionUtils
    {
        private static ExceptionUtils current = null;
        private static object lockObject = new object();

        public static ExceptionUtils Current
        {
            get
            {
                if (current == null)
                {
                    System.Threading.Interlocked.CompareExchange(ref current,new ExceptionUtils(), null);
                }
                return current;
            }
        }

        public void Handle(Exception e)
        {
            string logFile = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"logs");
            if (!System.IO.Directory.Exists(logFile))
            {
                System.IO.Directory.CreateDirectory(logFile);
            }
            string ExceptionName = e.GetType().Name;
            logFile = logFile + "\\" + ExceptionName;
            string filePath = logFile + DateTime.Now.ToString("yyyyMMdd") + ".log";

            using (StreamWriter sw = new StreamWriter(filePath, true, System.Text.Encoding.Default))
            {
                //确保线程安全
                TextWriter tw = TextWriter.Synchronized(sw);
                tw.Write(GetExceptionInfo(e));
                tw.Close();
            }
        }
        public static string GetExceptionInfo(Exception e)
        {
            string ExceptionName = e.GetType().Name;
            StringBuilder sb = new StringBuilder();
            sb.Append("---------------------Header-----------------");
            sb.Append(Environment.NewLine);
            sb.Append("<" + ExceptionName + ">\n");
            sb.Append(Environment.NewLine);
            sb.Append("<LogDateTime>" + DateTime.Now.ToString() + "</LogDateTime>\n");
            sb.Append(Environment.NewLine);
            sb.Append("<Message>" + System.Net.WebUtility.HtmlEncode(e.Message) + "</Message>\n");
            sb.Append(Environment.NewLine);
            if (e.Source != null)
            {
                sb.Append("<Source>" + e.Source + "</Source>\n");
                sb.Append(Environment.NewLine);
            }
            if (e.StackTrace != null)
            {
                sb.Append("<StackTrace>" + e.StackTrace + "</StackTrace>\n");
                sb.Append(Environment.NewLine);
            }
            if (e.InnerException != null)
            {
                sb.Append("<InnerException>" + System.Net.WebUtility.HtmlEncode(e.InnerException.ToString()) + "</InnerException>\n");
                sb.Append(Environment.NewLine);
            }
            sb.Append("<TargetSite>" + e.TargetSite + "</TargetSite>\n");
            sb.Append(Environment.NewLine);
            sb.Append("</" + ExceptionName + ">\n");
            sb.Append(Environment.NewLine);
            sb.Append("---------------------Footer-----------------");
            sb.Append(Environment.NewLine);

            return sb.ToString();
        }
    }
}