/*  Screem:  screem-icon-cache.c
 *
 *  Copyright (C) 2004 David A Knight
 *
 *  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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 *
 *  For contact information with the author of this source code please see
 *  the AUTHORS file.  If there is no AUTHORS file present then check the
 *  about box under the help menu for a contact address
 */
#include <config.h>

#include <gtk/gtk.h>
#include <glib.h>
#include <libgnomeui/gnome-icon-lookup.h>
#include <libgnomeui/gnome-thumbnail.h>

#include "screem-icon-cache.h"

struct ScreemIconCachePrivate {
	GtkIconTheme *theme;
	GnomeThumbnailFactory *small_thumbs;
	GnomeThumbnailFactory *large_thumbs;

	GHashTable *hash;
};

enum {
	ARG_0
};

enum {
	CHANGED,
	LAST_SIGNAL
};

static guint screem_icon_cache_signals[ LAST_SIGNAL ] = { 0 };

static void screem_icon_cache_theme_changed( GtkIconTheme *theme,
		ScreemIconCache *cache );
static gchar *screem_icon_cache_get_name( ScreemIconCache *cache,
		const gchar *uri, const gchar *mime_type,
		gboolean thumbnail, GnomeThumbnailSize thumb_size );
static GdkPixbuf *screem_icon_cache_get_icon( ScreemIconCache *cache,
		const gchar *uri, const gchar *mime_type,
		gboolean thumbnail, GnomeThumbnailSize thumb_size, 
		gint size );

/* G Object stuff */
G_DEFINE_TYPE( ScreemIconCache, screem_icon_cache, G_TYPE_OBJECT )

static void screem_icon_cache_finalize( GObject *object );
static void screem_icon_cache_set_prop( GObject *object, 
		guint property_id, const GValue *value, 
		GParamSpec *pspec );
static void screem_icon_cache_get_prop( GObject *object, 
		guint property_id, GValue *value, GParamSpec *pspec );

static void screem_icon_cache_class_init( ScreemIconCacheClass *klass )
{
	GObjectClass *object_class;

	object_class = G_OBJECT_CLASS( klass );

	object_class->finalize = screem_icon_cache_finalize;
	screem_icon_cache_parent_class = g_type_class_peek_parent( klass );

	object_class->get_property = screem_icon_cache_get_prop;
	object_class->set_property = screem_icon_cache_set_prop;

	screem_icon_cache_signals[ CHANGED ] =
		g_signal_new( "changed",
			      G_OBJECT_CLASS_TYPE( object_class ),
			      G_SIGNAL_RUN_LAST,
			      G_STRUCT_OFFSET( ScreemIconCacheClass, 
					       changed ),
			      NULL, NULL,
			      g_cclosure_marshal_VOID__VOID,
			      G_TYPE_NONE, 0 );
}

static void screem_icon_cache_init( ScreemIconCache *icon_cache )
{
	ScreemIconCachePrivate *priv;
	GtkIconTheme *theme;
	
	priv = icon_cache->priv = g_new0( ScreemIconCachePrivate, 1 );

	theme = priv->theme = gtk_icon_theme_get_default();
	
	g_signal_connect( G_OBJECT( theme ), "changed",
			G_CALLBACK( screem_icon_cache_theme_changed ),
			icon_cache );
	
	priv->small_thumbs = gnome_thumbnail_factory_new( GNOME_THUMBNAIL_SIZE_NORMAL );

	priv->large_thumbs = gnome_thumbnail_factory_new( GNOME_THUMBNAIL_SIZE_LARGE );

	priv->hash = g_hash_table_new_full( g_str_hash, g_str_equal,
			(GDestroyNotify)g_free,
			(GDestroyNotify)g_object_unref );
}

static void screem_icon_cache_finalize( GObject *object )
{
	ScreemIconCache *icon_cache;
	ScreemIconCachePrivate *priv;
	
	icon_cache = SCREEM_ICON_CACHE( object );
	priv = icon_cache->priv;

	if( priv->theme ) {
		g_object_unref( priv->theme );
	}
	if( priv->small_thumbs ) {
		g_object_unref( priv->small_thumbs );
	}
	if( priv->large_thumbs ) {
		g_object_unref( priv->large_thumbs );
	}
	if( priv->hash ) {
		g_hash_table_destroy( priv->hash );
	}
	
	g_free( priv );
	
	G_OBJECT_CLASS( screem_icon_cache_parent_class )->finalize( object );
}

static void screem_icon_cache_set_prop( GObject *object, 
		guint property_id, const GValue *value, 
		GParamSpec *pspec )
{
	ScreemIconCache *icon_cache;
	ScreemIconCachePrivate *priv;
	
	icon_cache = SCREEM_ICON_CACHE( object );
	priv = icon_cache->priv;
	
	switch( property_id ) {
		default:
			break;
	}
}

static void screem_icon_cache_get_prop( GObject *object, 
		guint property_id, GValue *value, GParamSpec *pspec )
{
	ScreemIconCache *icon_cache;
	ScreemIconCachePrivate *priv;
	
	icon_cache = SCREEM_ICON_CACHE( object );
	priv = icon_cache->priv;
	
	switch( property_id ) {
		default:
			break;
	}
}

/* Private API */
static void screem_icon_cache_theme_changed( GtkIconTheme *theme,
		ScreemIconCache *cache )
{
	ScreemIconCachePrivate *priv;

	priv = cache->priv;

	g_hash_table_destroy( priv->hash );
	
	priv->hash = g_hash_table_new_full( g_str_hash, g_str_equal,
			(GDestroyNotify)g_free,
			(GDestroyNotify)g_object_unref );

	g_signal_emit( G_OBJECT( cache ),
		       screem_icon_cache_signals[ CHANGED ], 0 );
}

static gchar *screem_icon_cache_get_name( ScreemIconCache *cache,
		const gchar *uri, const gchar *mime_type,
		gboolean thumbnail, GnomeThumbnailSize thumb_size )
{
	ScreemIconCachePrivate *priv;
	GtkIconTheme *theme;
	GnomeThumbnailFactory *thumbs;
	const gchar *custom_icon;
	GnomeIconLookupFlags flags;
	GnomeIconLookupResultFlags result;
	gchar *icon;

	g_return_val_if_fail( SCREEM_IS_ICON_CACHE( cache ), NULL );
	
	priv = cache->priv;

	theme = priv->theme;
	
	if( ! thumbnail ) {
		thumbs = NULL;
	} else if( thumb_size == GNOME_THUMBNAIL_SIZE_LARGE ) {
		thumbs = priv->large_thumbs;
	} else {
		thumbs = priv->small_thumbs;
	}
	
	custom_icon = NULL;
	
	flags = GNOME_ICON_LOOKUP_FLAGS_NONE;
	
	icon = gnome_icon_lookup( theme, thumbs, uri, custom_icon, 
			NULL /*GnomeVFSFileInfo*/, 
			mime_type, flags, &result );

	return icon;
}

static GdkPixbuf *screem_icon_cache_get_icon( ScreemIconCache *cache,
		const gchar *uri, const gchar *mime_type,
		gboolean thumbnail, GnomeThumbnailSize thumb_size, 
		gint size )
{
	ScreemIconCachePrivate *priv;
	gchar *icon;
	gchar *lookup;
	GtkIconLookupFlags flags;
	GError *error;
	GdkPixbuf *pixbuf;
	guint width;
	guint height;
	guint max;
	gdouble factor;
	GdkPixbuf *scale;
	
	g_return_val_if_fail( SCREEM_IS_ICON_CACHE( cache ), NULL );
	
	priv = cache->priv;
	
	icon = screem_icon_cache_get_name( cache, uri, mime_type,
			thumbnail, thumb_size );

	pixbuf = NULL;
	
	if( icon ) {

		if( ! thumbnail ) {
			lookup = g_strdup_printf( "%s-%i", icon, size );
		} else {
			lookup = g_strdup_printf( "%s-%i-thumb-%i", 
					icon, size, (gint)thumb_size );
		}
		
		pixbuf = g_hash_table_lookup( priv->hash, lookup );

		if( ! pixbuf ) {
			flags = GTK_ICON_LOOKUP_USE_BUILTIN;
			error = NULL;
		
			pixbuf = gtk_icon_theme_load_icon( priv->theme,
					icon, size, flags, &error );
		
			if( pixbuf ) {
				width = gdk_pixbuf_get_width( pixbuf );
				height = gdk_pixbuf_get_height( pixbuf );
				max = MAX( width, height );
				factor = ( size / (gdouble) max );
				if( factor != 1.0 ) {	
					width = (guint)width * factor;
					height = (guint)height * factor;
					scale = gdk_pixbuf_scale_simple( pixbuf, width, height, GDK_INTERP_HYPER );
					if( scale ) {
						g_object_unref( pixbuf );
						pixbuf = scale;
					}
				}
				
				g_hash_table_insert( priv->hash,
						g_strdup( lookup ),
						pixbuf );
			} else if( error ) {
				g_error_free( error );
			}
		} 
		if( pixbuf ) {
			g_object_ref( pixbuf );
		}
		
		g_free( lookup );
		g_free( icon );
	}
	return pixbuf;
}

/* Public API */

ScreemIconCache *screem_icon_cache_new( void )
{
	ScreemIconCache *icon_cache;

	icon_cache = SCREEM_ICON_CACHE( g_object_new( SCREEM_TYPE_ICON_CACHE, 
				NULL ) );

	return icon_cache;
}

GdkPixbuf *screem_icon_cache_get_pixbuf( ScreemIconCache *cache,
		const gchar *uri, const gchar *mime_type, gint size )
{
	GdkPixbuf *ret;

	g_return_val_if_fail( SCREEM_IS_ICON_CACHE( cache ), NULL );
	g_return_val_if_fail( ( uri != NULL || mime_type != NULL ), 
			NULL );
		
	ret = screem_icon_cache_get_icon( cache, uri, mime_type,
			FALSE, GNOME_THUMBNAIL_SIZE_NORMAL, size );

	return ret;
}

GdkPixbuf *screem_icon_cache_get_thumbnail( ScreemIconCache *cache,
		const gchar *uri, const gchar *mime_type, gint size )
{
	GdkPixbuf *ret;

	g_return_val_if_fail( SCREEM_IS_ICON_CACHE( cache ), NULL );
	g_return_val_if_fail( ( uri != NULL || mime_type != NULL ), 
			NULL );
	
	ret = screem_icon_cache_get_icon( cache, uri, mime_type,
			FALSE, GNOME_THUMBNAIL_SIZE_NORMAL, size );

	return ret;
}

GdkPixbuf *screem_icon_cache_get_large_thumbnail( ScreemIconCache *cache,
		const gchar *uri, const gchar *mime_type, gint size )
{
	GdkPixbuf *ret;

	g_return_val_if_fail( SCREEM_IS_ICON_CACHE( cache ), NULL );
	g_return_val_if_fail( ( uri != NULL || mime_type != NULL ), 
			NULL );
	
	ret = screem_icon_cache_get_icon( cache, uri, mime_type,
			FALSE, GNOME_THUMBNAIL_SIZE_LARGE, size );

	return ret;
}