/*
* Copyright (C) 2010 Canonical Ltd
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* 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/>.
*
* Authored by: Neil Jagdish Patel <neil.patel@canonical.com>
*/

#ifndef ICON_LOADER_H
#define ICON_LOADER_H

#include <string>
#include <map>
#include <vector>
#include <sigc++/sigc++.h>
#include <gtk/gtk.h>

class IconLoader
{
public:
  typedef sigc::slot<void, const char *, guint, GdkPixbuf *> IconLoaderCallback;

  IconLoader ();
  ~IconLoader ();

 // DO NOT `delete` this...ever.
 static IconLoader * GetDefault ();

 void LoadFromIconName    (const char        *icon_name,
                           guint              size,
                           IconLoaderCallback slot);

 void LoadFromGIconString (const char        *gicon_string,
                           guint              size,
                           IconLoaderCallback slot);

 void LoadFromFilename    (const char        *filename,
                           guint              size,
                           IconLoaderCallback slot);

 void LoadFromURI         (const char        *uri,
                           guint              size,
                           IconLoaderCallback slot);
private:

  enum IconLoaderRequestType
  {
    REQUEST_TYPE_ICON_NAME=0,
    REQUEST_TYPE_GICON_STRING,
    REQUEST_TYPE_URI,
  };

  struct IconLoaderTask
  {
    IconLoaderRequestType type;
    char                 *data;
    guint                 size;
    char                 *key;
    IconLoaderCallback    slot;
    IconLoader           *self;
  };


  void   QueueTask (const char           *key,
                    const char           *data,
                    guint                 size,
                    IconLoaderCallback    slot,
                    IconLoaderRequestType type);
  char * Hash (const char *data, guint size);
  bool   CacheLookup (const char *key,
                      const char *data,
                      guint       size,
                      IconLoaderCallback slot);
  bool   ProcessTask (IconLoaderTask *task);
  bool   ProcessIconNameTask (IconLoaderTask *task);
  bool   ProcessGIconTask (IconLoaderTask *task);
  bool   ProcessURITask (IconLoaderTask *task);
  void   ProcessURITaskReady (IconLoaderTask *task, char *contents, gsize length);
  bool   Iteration ();
  void   FreeTask (IconLoaderTask *task);

  static bool Loop (IconLoader *self);
  static void LoadContentsReady (GObject *object, GAsyncResult *res, IconLoaderTask *task);
 
private:
  bool _no_load;

  std::map<std::string, GdkPixbuf *> _cache;
  GQueue       *_tasks;
  guint         _idle_id;
  GtkIconTheme *_theme;
  gint64        _idle_start_time;
};

#endif // ICON_LOADER_H