/grawler/TvdbLib/Data/Banner/TvdbBanner.cs

/*

 *   TvdbLib: A library to retrieve information and media from http://thetvdb.com

 * 

 *   Copyright (C) 2008  Benjamin Gmeiner

 * 

 *   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 3 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, see <http://www.gnu.org/licenses/>.

 * 

 */



using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Drawing;

using System.Net;

using System.IO;

using System.Threading;

using TvdbLib.Cache;



namespace TvdbLib.Data

{

  /// <summary>

  /// Tvdb Banners are the graphical element of tvdb. There are different types of banners which are

  /// representet by sub-classes in this library. These subclasses are:

  /// <list type="bullet">

  /// <item>

  ///   <term>TvdbEpisodeBanner</term>

  ///   <description>Each episode may contain a small image that should be an non-spoiler action shot from the episode (http://thetvdb.com/wiki/index.php/Episode_Images)</description>

  /// </item>                 

  /// <item>

  ///   <term>TvdbFanartBanner</term>

  ///   <description>Fan Art is high quality artwork that is displayed in the background of HTPC menus (http://thetvdb.com/wiki/index.php/Fan_Art)</description>

  /// </item>                    

  /// <item>

  ///   <term>TvdbSeasonBanner</term>

  ///   <description>Banner for each season of a series, dvd-style (400 x 578) or banner style (758 x 140) (http://thetvdb.com/wiki/index.php/Wide_Season_Banners)</description>

  /// </item>                    

  /// <item>

  ///   <term>TvdbSeriesBanner</term>

  ///   <description>Wide banner for each series (758 x 140), comes in graphical, text or blank style. For further information see http://thetvdb.com/wiki/index.php/Series_Banners</description>

  /// </item>                    

  /// <item>

  ///   <term>TvdbPosterBanner</term>

  ///   <description>Newest addition to the tvdb graphical section (680px x 1000px) and not smaller than 500k (http://thetvdb.com/wiki/index.php/Posters)</description>

  /// </item>                    

  /// </list>

  /// </summary>

  [Serializable]

  public class TvdbBanner

  {

    #region private/protected fields

    private String m_bannerPath;

    private Image m_banner;

    private bool m_isLoaded;

    private int m_id;

    private TvdbLanguage m_language;

    private bool m_bannerLoading = false;

    private System.Object m_bannerLoadingLock = new System.Object();

    private DateTime m_lastUpdated;

    private int m_seriesId;

    private ICacheProvider m_cacheProvider;

    #endregion



    /// <summary>

    /// Used to load/save images persistent if we're using a cache provider 

    /// (should keep memory usage much lower)

    /// on the other hand we have a back-ref to tvdb (from a data class), which sucks

    /// </summary>

    public ICacheProvider CacheProvider

    {

      get { return m_cacheProvider; }

      set { m_cacheProvider = value; }

    }



    /// <summary>

    /// Language of the banner

    /// </summary>

    public TvdbLanguage Language

    {

      get { return m_language; }

      set { m_language = value; }

    }



    /// <summary>

    /// Id of the banner

    /// </summary>

    public int Id

    {

      get { return m_id; }

      set { m_id = value; }

    }



    /// <summary>

    /// Image data of the banner

    /// </summary>

    public Image BannerImage

    {

      get { return m_banner; }

      set { m_banner = value; }

    }



    /// <summary>

    /// True if the image data has been already loaded, false otherwise

    /// </summary>

    public bool IsLoaded

    {

      get { return m_isLoaded; }

    }



    /// <summary>

    /// Is the banner currently beeing loaded

    /// </summary>

    public bool BannerLoading

    {

      get { return m_bannerLoading; }

      set { m_bannerLoading = value; }

    }



    /// <summary>

    /// Path to the location on the tvdb server where the image is located

    /// </summary>

    public String BannerPath

    {

      get { return m_bannerPath; }

      set { m_bannerPath = value; }

    }



    /// <summary>

    /// When was the banner updated the last time

    /// </summary>

    public DateTime LastUpdated

    {

      get { return m_lastUpdated; }

      set { m_lastUpdated = value; }

    }



    /// <summary>

    /// Id of the series this banner belongs to

    /// </summary>

    public int SeriesId

    {

      get { return m_seriesId; }

      set { m_seriesId = value; }

    }



    /// <summary>

    /// Loads the actual image data of the banner

    /// </summary>

    /// <returns>true if the banner could be loaded successfully, false otherwise</returns>

    public bool LoadBanner()

    {

      return LoadBanner(false);

    }



    /// <summary>

    /// Loads the actual image data of the banner

    /// </summary>

    /// <param name="_replaceOld">If true will replace an old image (if one exists already)</param>

    /// <returns>true if the banner could be loaded successfully, false otherwise</returns>

    public bool LoadBanner(bool _replaceOld)

    {

      bool wasLoaded = m_isLoaded;//is the banner already loaded at this point

      lock (m_bannerLoadingLock)

      {//if another thread is already loading THIS banner, the lock will block this thread until the other thread

        //has finished loading

        if (!wasLoaded && !_replaceOld && m_isLoaded)

        {////the banner has already been loaded from a different thread and we don't want to replace it

          return false;

        }



        m_bannerLoading = true;

        if (m_bannerPath.Equals("")) return false;

        try

        {

          Image img = null;

          String cacheName = CreateCacheName(m_bannerPath, false);

          if (m_cacheProvider != null && m_cacheProvider.Initialised)

          {//try to load the image from cache first

            img = m_cacheProvider.LoadImageFromCache(m_seriesId, cacheName);

          }



          if (img == null)

          {//couldn't load image from cache -> load it from http://thetvdb.com

            img = LoadImage(TvdbLinkCreator.CreateBannerLink(m_bannerPath));



            if (img != null && m_cacheProvider != null && m_cacheProvider.Initialised)

            {//store the image to cache

              m_cacheProvider.SaveToCache(img, m_seriesId, cacheName);

            }

          }



          if (img != null)

          {//image was successfully loaded

            m_banner = img;

            m_isLoaded = true;

            m_bannerLoading = false;

            return true;

          }

        }

        catch (WebException ex)

        {

          Log.Error("Couldn't load banner " + m_bannerPath, ex);

        }

        m_isLoaded = false;

        m_bannerLoading = false;

        return false;

      }

    }



    /// <summary>

    /// Unloads the image and saves it to cache

    /// </summary>

    /// <returns>true if successful, false otherwise</returns>

    public bool UnloadBanner()

    {

      return UnloadBanner(true);

    }



    /// <summary>

    /// Unloads the image

    /// </summary>

    /// <param name="_saveToCache">should the image kept in cache</param>

    /// <returns>true if successful, false otherwise</returns>

    public bool UnloadBanner(bool _saveToCache)

    {

      if (m_bannerLoading)

      {//banner is currently loading

        Log.Warn("Can't remove banner while it's loading");

        return false;

      }

      else

      {

        try

        {

          if (m_isLoaded)

          {

            LoadBanner(null);

          }

          if (!_saveToCache)

          {//we don't want the image in cache -> if we already cached it it should be deleted

            String cacheName = CreateCacheName(m_bannerPath, false);

            if (m_cacheProvider != null && m_cacheProvider.Initialised)

            {//try to load the image from cache first

              m_cacheProvider.RemoveImageFromCache(m_seriesId, cacheName);

            }

          }

        }

        catch (Exception ex)

        {

          Log.Warn("Error while unloading banner", ex);

        }

        return true;

      }

    }



    /// <summary>

    /// Creates the name used to store images in cache

    /// </summary>

    /// <param name="_path">Path of the image</param>

    /// <param name="_thumb">Is the image a thumbnail</param>

    /// <returns>Name used for caching image</returns>

    protected String CreateCacheName(String _path, bool _thumb)

    {

      if (_path.Contains("_cache/"))

      {

        _path = _path.Replace("_cache/", "");

      }

      if (_path.Contains("fanart/original/"))

      {

        _path = _path.Replace("fanart/original/", "fan-");

      }

      else if (_path.Contains("fanart/vignette/"))

      {

        _path = _path.Replace("fanart/vignette/", "fan-vig-");

      }

      _path = _path.Replace('/', '_');

      return (_thumb ? "thumb_": "img_") + _path;

    }



    /// <summary>

    /// Loads the banner with the given image

    /// </summary>

    /// <param name="_img">Image object that should be used for this banner</param>

    /// <returns>True if successful, false otherwise</returns>

    public bool LoadBanner(Image _img)

    {

      if (_img != null)

      {

        m_banner = _img;

        m_isLoaded = true;

        return true;

      }

      else

      {

        m_banner = null;

        m_isLoaded = false;

        return false;

      }

    }



    /// <summary>

    /// Loads the image from the given path

    /// </summary>

    /// <param name="_path">Path of image that should be used for this banner</param>

    /// <returns>True if successful, false otherwise</returns>

    protected Image LoadImage(String _path)

    {

      try

      {

        WebClient client = new WebClient();

        byte[] imgData = client.DownloadData(_path);

        MemoryStream ms = new MemoryStream(imgData);

        Image img = Image.FromStream(ms, true, true);

        return img;

      }

      catch (Exception ex)

      {

        Log.Error("Error while loading image ", ex);

        return null;

      }

    }

  }

}