/*
 * Copyright (C) 2007 Ross Burton
 *
 * Author: Ross Burton <ross@burtonini.com>
 *
 * 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.
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif /* HAVE_CONFIG_H */

#include <glib.h>
#include <gtk/gtkliststore.h>
#include "egg-pixbuf-thumbnail.h"
#include "thumbnailer.h"

static GStaticMutex thumbnail_queue_lock = G_STATIC_MUTEX_INIT;
static guint thumbnail_idle_id;
static GAsyncQueue *thumbnail_queue;
static GThreadPool *thumbnailer_pool;

static gboolean
set_thumbnail (gpointer user_data)
{
  ThumbnailData *data;
  GtkListStore *store;

  g_return_val_if_fail (GTK_IS_LIST_STORE (user_data), FALSE);
  store = user_data;

  /* TODO: can I lock this any later? I don't want to race between this loop
     ending and the handler being re-registered. */

  g_static_mutex_lock (&thumbnail_queue_lock);

  while ((data = g_async_queue_try_pop (thumbnail_queue)) != NULL) {
    if (data->thumb) {
      gtk_list_store_set (store, &data->iter, COL_THUMB, data->thumb, -1);
      gdk_pixbuf_unref (data->thumb);
    }
    
    g_object_unref (data->file);
    g_slice_free (ThumbnailData, data);
  }
  
  thumbnail_idle_id = 0;
  g_static_mutex_unlock (&thumbnail_queue_lock);

  return FALSE;
}

/* TODO: integrate gvfs into EggPixbufThumbnail */
static void
thumbnail_thread (gpointer thread_data, gpointer user_data)
{
  ThumbnailData *data = thread_data;
  char *path;
  
  g_assert (data);

  path = g_file_get_path (data->file);
  /* TODO: if thumbnail doesn't exist, attempt to read JPEG thumbnail with libexif */
  data->thumb = egg_pixbuf_get_thumbnail_for_file (path, EGG_PIXBUF_THUMBNAIL_NORMAL, NULL);
  g_free (path);

  g_async_queue_push (thumbnail_queue, data);

  g_static_mutex_lock (&thumbnail_queue_lock);
  if (thumbnail_idle_id == 0) {
    thumbnail_idle_id = g_timeout_add (50, set_thumbnail, user_data);
  }
  g_static_mutex_unlock (&thumbnail_queue_lock);
}

void
thumbnailer_push (ThumbnailData *data)
{
  g_return_if_fail (data != NULL);

  g_thread_pool_push (thumbnailer_pool, data, NULL);
}

void 
thumbnailer_init (KatachiImageStore *liststore)
{
  g_return_if_fail (KATACHI_IS_IMAGE_STORE (liststore));

  thumbnail_idle_id = 0;
  thumbnailer_pool = g_thread_pool_new (thumbnail_thread, liststore, 4, FALSE, NULL);
  thumbnail_queue = g_async_queue_new ();
}