TickerLib/Helper/FeedSerializer.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.IO;
using System.Windows.Media;
using MarketData.Utils;
using Ticker.Models;
//  Author:Sean Kessler
namespace Ticker.Helper
{
  public class FeedSerializer
  {
    private FeedSerializer()
    {
    }
    public static List<FeedItem> Deserialize(String strPathFileName)
    {
      List<FeedItem> feedItems=new List<FeedItem>();
      if(!File.Exists(strPathFileName))return feedItems;
      String strLine=null;

      if(!IsCacheCurrent(strPathFileName,DateTime.Now))
      {
        RemoveCache(strPathFileName);
        return feedItems;
      }
      StreamReader streamReader=new StreamReader(new FileStream(strPathFileName,FileMode.Open));
      DateTime cacheDate=new NVP(streamReader.ReadLine()).Get<DateTime>();
      while(null!=(strLine=streamReader.ReadLine()))
      {
        if("".Equals(strLine))continue;
        FeedItem feedItem=FeedItem.FromString(strLine);
        if(null==feedItem)continue;
        feedItems.Add(feedItem);
      }
      streamReader.Close();
      streamReader.Dispose();
      return feedItems;
    }
    public static bool Serialize(String strPathFileName,DateTime feedDate,List<FeedItem> feedsList)
    {
      try
      {
        if(File.Exists(strPathFileName))File.Delete(strPathFileName);
        StreamWriter streamWriter=new StreamWriter(new FileStream(strPathFileName,FileMode.CreateNew));
        streamWriter.WriteLine(new NVP("CacheDate",feedDate.ToShortDateString()).ToString());
        foreach(FeedItem feedItem in feedsList)
        {
          String strLine=feedItem.ToNVPCollection().ToString();
          if(null==strLine||"".Equals(strLine))continue;
          streamWriter.WriteLine(strLine);
        }
        streamWriter.Flush();
        streamWriter.Close();
        streamWriter.Dispose();
        return true;
      }
      catch(Exception)
      {
        return false;
      }
    }
    public static bool Serialize(String strPathFileName,DateTime feedDate,FeedItem feedItem)
    {
      try
      {
        StreamWriter streamWriter=null;
        String strLine=feedItem.ToNVPCollection().ToString();
        if(null==strLine||"".Equals(strLine))return false;
        if(!File.Exists(strPathFileName))
        {
          streamWriter=new StreamWriter(new FileStream(strPathFileName,FileMode.CreateNew));
          streamWriter.WriteLine(new NVP("CacheDate",feedDate.ToShortDateString()).ToString());
        }
        else 
        {
          streamWriter=new StreamWriter(new FileStream(strPathFileName,FileMode.Append));
        }
        streamWriter.WriteLine(strLine);
        streamWriter.Flush();
        streamWriter.Close();
        streamWriter.Dispose();
        return true;
      }
      catch(Exception)
      {
        return false;
      }
    }
    private static bool IsCacheCurrent(String strPathFileName,DateTime feedDate)
    {
      try
      {
        if(!File.Exists(strPathFileName))return false;
        StreamReader streamReader=new StreamReader(new FileStream(strPathFileName,FileMode.Open));
        DateTime cacheDate=new NVP(streamReader.ReadLine()).Get<DateTime>();
        streamReader.Close();
        return feedDate.Date.Equals(cacheDate.Date);
      }
      catch(Exception)
      {
        return false;
      }
    }
    private static void RemoveCache(String strPathFileName)
    {
      try
      {
        if(File.Exists(strPathFileName))File.Delete(strPathFileName);
      }
      catch(Exception)
      {
      }
    }
  }
}