DownloadManager.cs :  » Business-Application » DC » DCSharp » Backend » Managers » C# / CSharp Open Source

/* 
 * Copyright (C) 2004-2005 Jonathan Bindel
 * Copyright (C) 2006-2007 Eskil Bylund
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Xml.Serialization;

using DCSharp.Backend.Objects;
using DCSharp.Xml;

namespace DCSharp.Backend.Managers{
  public class DownloadManager : IEnumerable<DownloadFileInfo>
  {
    public event EventHandler<DownloadEventArgs> DownloadAdded;
    public event EventHandler<DownloadEventArgs> DownloadRemoved;
    
    private List<DownloadFileInfo> downloads;
    private Downloader downloader;
    
    #region Constructors
    
    public DownloadManager(ConnectionManager connectionManager,
      Listener listener)
    {
      downloads = new List<DownloadFileInfo>();
      
      downloader = new Downloader(connectionManager, this, listener);
    }

    #endregion

    #region Properties
    
    public int Count
    {
      get { return downloads.Count; }
    }
    
    public object SyncRoot
    {
      get { return downloads; }
    }

    #endregion

    #region Methods

    public void Add(DownloadFileInfo download)
    {
      if (download == null)
      {
        throw new ArgumentNullException("download");
      }
      lock (downloads)
      {
        if (Contains(download))
        {
          return;
        }
        downloads.Add(download);
        OnDownloadAdded(download);
      }
    }

    public void Remove(DownloadFileInfo download)
    {
      if (download == null)
      {
        throw new ArgumentNullException("download");
      }
      lock (downloads)
      {
        if (!Contains(download))
        {
          return;
        }
        downloads.Remove(download);
        OnDownloadRemoved(download);
      }
      
      // Remove the temp file
      if (download.TempTarget != null)
      {
        string tempFile = Path.Combine(download.TempTarget,
          download.Name + ".dctmp");
        if (File.Exists(tempFile))
        {
          File.Delete(tempFile);
        }
      }
    }

    public bool Contains(DownloadFileInfo download)
    {
      return downloads.Contains(download);
    }

    public DownloadFileInfo Find(Predicate<DownloadFileInfo> match)
    {
      lock (downloads)
      {
        for (int i = 0; i < downloads.Count; i++)
        {
          if (match(downloads[i]))
          {
            return downloads[i];
          }
        }
      }
      return null;
    }

    public IEnumerator<DownloadFileInfo> GetEnumerator()
    {
      return downloads.GetEnumerator();
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
      return GetEnumerator();
    }

    public DownloadFileInfo AddFileList(User user)
    {
      if (user == null)
      {
        throw new ArgumentNullException("user");
      }
      
      DownloadFileInfo download = new DownloadFileInfo(user.Uid);
      download.Add(new SourceInfo(user, null));
      
      Add(download);
      
      return download;
    }

    public bool HasDownload(User user)
    {
      if (user == null)
      {
        throw new ArgumentNullException("user");
      }
      DownloadFileInfo download = Find(delegate(DownloadFileInfo d)
      {
        return d.HasSource(user);
      });
      return download != null;
    }

    public DownloadFileInfo GetDownload(string tth)
    {
      if (tth == null)
      {
        throw new ArgumentNullException("tth");
      }
      return Find(delegate(DownloadFileInfo download)
      {
        return download.TTH == tth;
      });
    }
    
    public void SetNextDownload(User user, DownloadFileInfo download,
      bool forceStart)
    {
      downloader.SetNextDownload(user, download, forceStart);
    }
    
    protected virtual void OnDownloadAdded(DownloadFileInfo download)
    {
      if (DownloadAdded != null)
      {
        DownloadAdded(this, new DownloadEventArgs(download));
      }
    }

    protected virtual void OnDownloadRemoved(DownloadFileInfo download)
    {
      if (DownloadRemoved != null)
      {
        DownloadRemoved(this, new DownloadEventArgs(download));
      }
    }
    
    // TODO: Let some other class handle the saving/loading of the downloads.
    public void Save(string filename)
    {
      lock (downloads)
      {
        Queue queue = new Queue();
        queue.Downloads = downloads.FindAll(delegate (DownloadFileInfo d)
        {
          return !d.IsFileList;
        });
        
        XmlHelper.Serialize(queue, filename);
      }
    }
    
    public void Load(string filename)
    {
      lock (downloads)
      {
        Queue queue = (Queue)XmlHelper.Deserialize(typeof(Queue), filename);
        foreach (DownloadFileInfo download in queue.Downloads)
        {
          if (download.Name != null && download.Target != null &&
            !download.IsFileList)
          {
            Add(download);
          }
        }
      }
    }
    
    // Helper class for xml serialization of downloads
    [XmlRoot("Downloads")]
    public class Queue
    {
      [XmlElement("Download")]
      public List<DownloadFileInfo> Downloads = new List<DownloadFileInfo>();
    }
    
    #endregion
  }
}