The Favalias Application

// Jean-Christophe Magnon
// jcmag@yahoo.com
#region Copyright � 2003 The Favalias Group
/*
 * This software is provided 'as-is', without any express or implied warranty.
 * In no event will the authors be held liable for any damages arising from the
 * use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not claim
 * that you wrote the original software. If you use this software in a product,
 * an acknowledgment in the product documentation is required, as shown here:
 *
 * Portions Copyright � 2003 The Favalias Group (http://sourceforge.net/projects/favalias).
 *
 * 2. Altered source versions must be plainly marked as such, and must not be 
 * misrepresented as being the original software.
 * 
 * 3. This notice may not be removed or altered from any source distribution.
*/
#endregion

#region Namespaces
using Favalias.Forms;
using System;
using System.Collections;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Net;
using System.Reflection;
using System.Runtime.Serialization.Formatters.Binary;
using System.Text.RegularExpressions;
using System.Threading;
using System.Windows.Forms;
using System.Xml;
using Toub.Threading;
#endregion

namespace Favalias.Controllers
{
	/// <summary>
	/// Load favicons with WebRequest.
	/// </summary>
	public class FaviconsController
	{
		#region Fields
		
		private FormProgress _formProgress;
		private static readonly log4net.ILog _log = log4net.LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
		private int _waitingRequests;
		private Hashtable _favicons;
		private FormFavalias _parent;
		private int _timeout;
		
		#endregion

		#region Initialization

		public FaviconsController(FormFavalias parent)
		{
			string timeout = System.Configuration.ConfigurationSettings.AppSettings["timeoutForLoadingFavicons"];
			_timeout = 15000; // 15 seconds by default
			if(timeout.Length != 0)
			{
				Regex myRegex = new Regex(@"\d{1,6}");
				if(myRegex.IsMatch(timeout))
					_timeout = Convert.ToInt32(timeout);
			}				
			this._parent = parent;
			deserializeFavicons();
		}

		#endregion

		#region Properties
		
		public Hashtable Favicons
		{
			get
			{
				return _favicons;
			}
		}

		#endregion

		#region Public Methods
		public void LoadFavicons()
		{
			try
			{
				_favicons = new Hashtable();
				_formProgress = new FormProgress();
				_formProgress.Show();
				XmlDocument doc = new XmlDocument();
				doc.Load(FavaliasController.userPref.favoritesFile);
				_waitingRequests = doc.SelectNodes("//favorite").Count;
				_formProgress.progressBar1.Maximum = _waitingRequests;

				XmlNodeList categories = doc.SelectNodes("favorites/category");	
				foreach(XmlNode node in categories)
				{
					recurseCategory(node);
					recurseFavorites(node);
				}
			}
			catch(Exception exc)
			{
				Debug.WriteLine(exc);
				if(_log.IsErrorEnabled) _log.Error(MethodBase.GetCurrentMethod().Name, exc);
			}
		}

		#endregion

		#region Private Methods
		/// <summary>
		/// Deserialize the Hashtable containing the _favicons (if _favicons.dat exists)
		/// </summary>
		private void deserializeFavicons()
		{
			try
			{
				_favicons = new Hashtable();
				BinaryFormatter formatter = new BinaryFormatter();
				string path = FavaliasController.appDataFolder + @"\_favicons.dat";
				if(File.Exists(path))
				{
					using(FileStream _formProgress = new FileStream(path, FileMode.Open))
					{
						_favicons = (Hashtable)formatter.Deserialize(_formProgress);
					}
				}
			}
			catch(Exception exc)
			{
				Debug.WriteLine(exc);
				if(_log.IsErrorEnabled) _log.Error(MethodBase.GetCurrentMethod().Name, exc);
			}
		}

		/// <summary>
		/// Serialize the Hashtable containing the _favicons in _favicons.dat
		/// </summary>
		private void serializeFavicons()
		{
			try
			{
				BinaryFormatter formatter = new BinaryFormatter();
				using(FileStream _formProgress = new FileStream(FavaliasController.appDataFolder + @"\_favicons.dat", FileMode.Create))
				{
					formatter.Serialize(_formProgress, _favicons);
				}
			}
			catch(Exception exc)
			{
				Debug.WriteLine(exc);
				if(_log.IsErrorEnabled) _log.Error(MethodBase.GetCurrentMethod().Name, exc);
			}
		}


		private void recurseCategory(XmlNode node)
		{
			XmlNodeList categories = node.SelectNodes("category");	
			foreach(XmlNode xnode in categories)
			{
				recurseCategory(xnode);
				recurseFavorites(xnode);
			}
		}

		private void recurseFavorites(XmlNode node)
		{
			XmlNodeList favorites = node.SelectNodes("favorite");	
			foreach(XmlNode xnode in favorites)
			{
				Uri completeUri = new Uri(xnode.InnerText);
				RequestState rs = new RequestState();
				rs.faviconName = xnode.Attributes["name"].Value;
				rs.faviconUri = "http://" + completeUri.Host + "/favicon.ico";

				PriorityThreadPool.QueueUserWorkItem(new WaitCallback(async_with_threadpool_step1), rs, 1);
			}
		}

		private void async_with_threadpool_step1(object state)
		{
			RequestState rs = state as RequestState;
			if(rs != null)
			{
				try
				{
					Debug.WriteLine("http://" + new Uri(rs.faviconUri).Host);
					WebRequest request = WebRequest.Create("http://" + new Uri(rs.faviconUri).Host);
					request.Timeout = _timeout;
					using(WebResponse resp = request.GetResponse())
					{
						//Debug.WriteLine("ContentType : " + ((HttpWebResponse)resp).ContentType);
						string contentType = ((HttpWebResponse)resp).ContentType;
						int deb = contentType.IndexOf("charset", 0);
						string encod = "ISO-8859-1";
						if(deb > 0)
							encod = contentType.Substring(deb + 8, contentType.Length - (deb + 8));
						//Debug.WriteLine("encod : " + encod);
						
						StreamReader reader = new StreamReader(resp.GetResponseStream(), System.Text.Encoding.GetEncoding(encod));
						string webPage = reader.ReadToEnd();
						string pattern = @"<link\s+rel\s*=""(shortcut)?\s*icon""\s+href\s*=\s*""([\w:/\.]+)"">";
						Regex regExp = new Regex(pattern, RegexOptions.IgnoreCase);
						for(Match m = regExp.Match(webPage); m.Success; m = m.NextMatch())
						{
							//Debug.WriteLine("Match : " + m.Value);
							string url = m.Groups[2].Value;
							//Debug.WriteLine("group (" + rs.faviconName + ") : " + url);
							if(url.StartsWith("\\") || url.StartsWith("/"))
								rs.faviconUri = "http://" + (new Uri(rs.faviconUri)).Host + url;
							else
								rs.faviconUri = url;
						}

					}
					Debug.WriteLine(MethodBase.GetCurrentMethod().Name + " - " + rs.faviconName + " ; rs.faviconUri : " + rs.faviconUri);
					if(_log.IsInfoEnabled) _log.Info(MethodBase.GetCurrentMethod().Name + " - " + rs.faviconName + " ; rs.faviconUri : " + rs.faviconUri);
					async_with_threadpool_step2(rs);

				}
				catch(Exception exc)
				{
					if(_formProgress != null)
					{
						_formProgress.PerformStep(rs.faviconName + " : " + exc.Message);
					}
					if(_log.IsInfoEnabled) _log.Info(MethodBase.GetCurrentMethod().Name + " - " + rs.faviconName, exc);
					Debug.WriteLine(rs.faviconName + " : " + exc.ToString());
					decreaseWaitingRequests();
				}
			}
		}
		
		private void async_with_threadpool_step2(object state)
		{
			RequestState rs = state as RequestState;
			if(rs != null)
			{
				try
				{
					WebRequest requestIcon = WebRequest.Create(rs.faviconUri);
					requestIcon.Timeout = _timeout;
					using(WebResponse response = requestIcon.GetResponse())
					{
						Debug.WriteLine(rs.faviconName + " - content type : " + response.ContentType);
						using(Stream myStream = response.GetResponseStream())
						{
//							byte[] bytes = new byte[response.ContentLength];
//							myStream.Read(bytes, 0, bytes.Length);
//							MemoryStream ms = new MemoryStream(bytes, 0, bytes.Length);							
							Image img = Image.FromStream(myStream);
							saveFavicon(rs.faviconName, img);
						}
					}
					if(_formProgress != null)
					{
						_formProgress.Invoke(new FormProgress.ProgressInvoker(_formProgress.PerformStep), new object[]{rs.faviconName + " : OK"});
					}
					if(_log.IsInfoEnabled) _log.Info(MethodBase.GetCurrentMethod().Name + " - " + rs.faviconName + " : OK");
				}
				catch(Exception exc)
				{
					if(_formProgress != null)
					{
						_formProgress.Invoke(new FormProgress.ProgressInvoker(_formProgress.PerformStep), new object[]{rs.faviconName + " : (" + exc.GetType().Name + ") -- " + exc.Message});
					}
					if(_log.IsInfoEnabled) _log.Info(MethodBase.GetCurrentMethod().Name + " - " + rs.faviconName, exc);
					Debug.WriteLine(rs.faviconName + " : " + exc.ToString());
				}
			}
			decreaseWaitingRequests();
		}

		private void decreaseWaitingRequests()
		{
			Interlocked.Decrement(ref _waitingRequests);
			if (_waitingRequests == 0)
			{
				if (_formProgress != null)
				{
					_formProgress.Invoke(new MethodInvoker(_formProgress.EndProgress));
				}
				serializeFavicons();
				_parent.loadFavorites();
			}
		}

		private void saveFavicon(string name, Image img)
		{
			if (img.Height > 1 && img.Width > 1)
			{
				Bitmap b = (img.Height > 16 && img.Width > 16) ? new Bitmap(img, 16, 16) : new Bitmap(img);
				lock(_favicons.SyncRoot)
				{
					_favicons.Add(name, b);
				}
				if(_log.IsInfoEnabled) _log.Info("adding in _favicons : " + name + " ; " + b.GetHashCode());
				Debug.WriteLine("adding in _favicons : " + name + " ; " + b.GetHashCode());
			}
		}
		#endregion

		
		/// <summary>
		/// Used to pass data across asynchronous calls
		/// </summary>
		internal class RequestState
		{
			public string faviconUri;
			public string faviconName;
		}
	}
}