/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8; c-indent-level: 8 -*- */
/*
 *  Copyright (C) 2004 Anders Carlsson <andersca@gnome.org>
 *
 *  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, 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.
 *
 */

#include <config.h>

#include "ev-utils.h"
#include "ev-file-helpers.h"

#include <string.h>
#include <math.h>
#include <glib/gi18n.h>

typedef struct
{
  int size;
  double *data;
} ConvFilter;

static double
gaussian (double x, double y, double r)
{
    return ((1 / (2 * M_PI * r)) *
	    exp ((- (x * x + y * y)) / (2 * r * r)));
}

static ConvFilter *
create_blur_filter (int radius)
{
  ConvFilter *filter;
  int x, y;
  double sum;
  
  filter = g_new0 (ConvFilter, 1);
  filter->size = radius * 2 + 1;
  filter->data = g_new (double, filter->size * filter->size);

  sum = 0.0;
  
  for (y = 0 ; y < filter->size; y++)
    {
      for (x = 0 ; x < filter->size; x++)
	{
	  sum += filter->data[y * filter->size + x] = gaussian (x - (filter->size >> 1),
								y - (filter->size >> 1),
								radius);
	}
    }

  for (y = 0; y < filter->size; y++)
    {
      for (x = 0; x < filter->size; x++)
	{
	  filter->data[y * filter->size + x] /= sum;
	}
    }

  return filter;
  
}

static GdkPixbuf *
create_shadow (GdkPixbuf *src, int blur_radius,
	       int x_offset, int y_offset, double opacity)
{
  int x, y, i, j;
  int width, height;
  GdkPixbuf *dest;
  static ConvFilter *filter = NULL;
  int src_rowstride, dest_rowstride;
  int src_bpp, dest_bpp;
  
  guchar *src_pixels, *dest_pixels;

  if (!filter)
    filter = create_blur_filter (blur_radius);

  if (x_offset < 0)
	  x_offset = (blur_radius * 4) / 5;
  
  if (y_offset < 0)
	  y_offset = (blur_radius * 4) / 5;

  
  width = gdk_pixbuf_get_width (src) + blur_radius * 2 + x_offset;
  height = gdk_pixbuf_get_height (src) + blur_radius * 2 + y_offset;

  dest = gdk_pixbuf_new (gdk_pixbuf_get_colorspace (src), TRUE,
			 gdk_pixbuf_get_bits_per_sample (src),
			 width, height);
  gdk_pixbuf_fill (dest, 0);  
  src_pixels = gdk_pixbuf_get_pixels (src);
  src_rowstride = gdk_pixbuf_get_rowstride (src);
  src_bpp = gdk_pixbuf_get_has_alpha (src) ? 4 : 3;
  
  dest_pixels = gdk_pixbuf_get_pixels (dest);
  dest_rowstride = gdk_pixbuf_get_rowstride (dest);
  dest_bpp = gdk_pixbuf_get_has_alpha (dest) ? 4 : 3;
  
  for (y = 0; y < height; y++)
    {
      for (x = 0; x < width; x++)
	{
	  int sumr = 0, sumg = 0, sumb = 0, suma = 0;

	  for (i = 0; i < filter->size; i++)
	    {
	      for (j = 0; j < filter->size; j++)
		{
		  int src_x, src_y;

		  src_y = -(blur_radius + x_offset) + y - (filter->size >> 1) + i;
		  src_x = -(blur_radius + y_offset) + x - (filter->size >> 1) + j;

		  if (src_y < 0 || src_y > gdk_pixbuf_get_height (src) ||
		      src_x < 0 || src_x > gdk_pixbuf_get_width (src))
		    continue;

		  sumr += src_pixels [src_y * src_rowstride +
				      src_x * src_bpp + 0] *
		    filter->data [i * filter->size + j];
		  sumg += src_pixels [src_y * src_rowstride +
				      src_x * src_bpp + 1] * 
		    filter->data [i * filter->size + j];

		  sumb += src_pixels [src_y * src_rowstride +
				      src_x * src_bpp + 2] * 
		    filter->data [i * filter->size + j];
		  
		  if (src_bpp == 4)
		    suma += src_pixels [src_y * src_rowstride +
					src_x * src_bpp + 3] *
		    filter->data [i * filter->size + j];
		  else
			  suma += 0xff;
		    
		}
	    }

	  if (dest_bpp == 4)
	    dest_pixels [y * dest_rowstride +
			 x * dest_bpp + 3] = (suma * opacity) / (filter->size * filter->size);

	}
    }
  
  return dest;
}

GdkPixbuf *
ev_pixbuf_add_shadow (GdkPixbuf *src, int size,
		      int x_offset, int y_offset, double opacity)
{
  GdkPixbuf *dest;
  
  dest = create_shadow (src, size, x_offset, y_offset, opacity);

  gdk_pixbuf_composite (src, dest,
			size, size,
			gdk_pixbuf_get_width (src),
			gdk_pixbuf_get_height (src),
 			size, size,
			1.0, 1.0,
			GDK_INTERP_NEAREST, 255);

  return dest;
}


/* Simple function to output the contents of a region.  Used solely for testing
 * the region code.
 */
void
ev_print_region_contents (cairo_region_t *region)
{
	gint n_rectangles, i;

	if (region == NULL) {
		g_print ("<empty region>\n");
		return;
	}

	g_print ("<region %p>\n", region);
	n_rectangles = cairo_region_num_rectangles (region);
	for (i = 0; i < n_rectangles; i++) {
		GdkRectangle rect;

		cairo_region_get_rectangle (region, i, &rect);
		g_print ("\t(%d %d, %d %d) [%dx%d]\n",
			 rect.x,
			 rect.y,
			 rect.x + rect.width,
			 rect.y + rect.height,
			 rect.width,
			 rect.height);
	}
}

static void
ev_gui_sanitise_popup_position (GtkMenu *menu,
				GtkWidget *widget,
				gint *x,
				gint *y)
{
	GdkScreen *screen = gtk_widget_get_screen (widget);
	gint monitor_num;
	GdkRectangle monitor;
	GtkRequisition req;

	g_return_if_fail (widget != NULL);

	gtk_widget_size_request (GTK_WIDGET (menu), &req);

	monitor_num = gdk_screen_get_monitor_at_point (screen, *x, *y);
	gtk_menu_set_monitor (menu, monitor_num);
	gdk_screen_get_monitor_geometry (screen, monitor_num, &monitor);

	*x = CLAMP (*x, monitor.x, monitor.x + MAX (0, monitor.width - req.width));
	*y = CLAMP (*y, monitor.y, monitor.y + MAX (0, monitor.height - req.height));
}

void
ev_gui_menu_position_tree_selection (GtkMenu   *menu,
				     gint      *x,
				     gint      *y,
				     gboolean  *push_in,
				     gpointer  user_data)
{
	GtkTreeSelection *selection;
	GList *selected_rows;
	GtkTreeModel *model;
	GtkTreeView *tree_view = GTK_TREE_VIEW (user_data);
	GtkWidget *widget = GTK_WIDGET (user_data);
	GtkRequisition req;
	GtkAllocation allocation;
	GdkRectangle visible;

	gtk_widget_size_request (GTK_WIDGET (menu), &req);
	gdk_window_get_origin (gtk_widget_get_window (widget), x, y);
	gtk_widget_get_allocation (widget, &allocation);

	*x += (allocation.width - req.width) / 2;

	/* Add on height for the treeview title */
	gtk_tree_view_get_visible_rect (tree_view, &visible);
	*y += allocation.height - visible.height;

	selection = gtk_tree_view_get_selection (tree_view);
	selected_rows = gtk_tree_selection_get_selected_rows (selection, &model);
	if (selected_rows)
	{
		GdkRectangle cell_rect;

		gtk_tree_view_get_cell_area (tree_view, selected_rows->data,
					     NULL, &cell_rect);

		*y += CLAMP (cell_rect.y + cell_rect.height, 0, visible.height);

		g_list_foreach (selected_rows, (GFunc)gtk_tree_path_free, NULL);
		g_list_free (selected_rows);
	}

	ev_gui_sanitise_popup_position (menu, widget, x, y);
}

/**
 * get_num_monitors: Get the number of user monitors.
 * @window: optional GtkWindow to look at.
 *
 * Returns: Number of monitors, -1 if uncertain situation (like multiple screens)
 */
gint 
get_num_monitors (GtkWindow *window)
{
	GdkDisplay *display; 
	GdkScreen *screen;
	gint num_screen;
	
	display = gdk_display_get_default ();
	num_screen = gdk_display_get_n_screens (display);
	
	if (num_screen != 1)
		return -1;
	
	if (window)
		screen = gtk_window_get_screen (window);
	else
		screen = gdk_display_get_screen (display, 0);

	return gdk_screen_get_n_monitors (screen);
}

void           
file_chooser_dialog_add_writable_pixbuf_formats (GtkFileChooser *chooser)
{
	GSList *pixbuf_formats = NULL;
	GSList *iter;
	GtkFileFilter *filter;
	int i;
  
	filter = gtk_file_filter_new();
	gtk_file_filter_set_name (filter, _("By extension"));
	g_object_set_data (G_OBJECT(filter), "pixbuf-format", NULL);
	gtk_file_chooser_add_filter (chooser, filter);

	pixbuf_formats = gdk_pixbuf_get_formats ();

	for (iter = pixbuf_formats; iter; iter = iter->next) {
		GdkPixbufFormat *format = iter->data;

	        gchar *description, *name, *extensions;
		gchar **extension_list, **mime_types;

		if (gdk_pixbuf_format_is_disabled (format) ||
	    	    !gdk_pixbuf_format_is_writable (format))
		            continue;

	        name = gdk_pixbuf_format_get_description (format);
	        extension_list = gdk_pixbuf_format_get_extensions (format);
	        extensions = g_strjoinv (", ", extension_list);
		g_strfreev (extension_list);
		description = g_strdup_printf ("%s (%s)", name, extensions);

		filter = gtk_file_filter_new ();
		gtk_file_filter_set_name (filter, description);
		g_object_set_data (G_OBJECT (filter), "pixbuf-format", format);
		gtk_file_chooser_add_filter (chooser, filter);

		g_free (description);
		g_free (extensions);
		g_free (name);

		mime_types = gdk_pixbuf_format_get_mime_types (format);
		for (i = 0; mime_types[i] != 0; i++)
			gtk_file_filter_add_mime_type (filter, mime_types[i]);
		g_strfreev (mime_types);
	}

	g_slist_free (pixbuf_formats);
}

GdkPixbufFormat*
get_gdk_pixbuf_format_by_extension (gchar *uri)
{
	GSList *pixbuf_formats = NULL;
	GSList *iter;
	int i;

	pixbuf_formats = gdk_pixbuf_get_formats ();

	for (iter = pixbuf_formats; iter; iter = iter->next) {
		gchar **extension_list;
		GdkPixbufFormat *format = iter->data;
		
		if (gdk_pixbuf_format_is_disabled (format) ||
	    	    !gdk_pixbuf_format_is_writable (format))
		            continue;

	        extension_list = gdk_pixbuf_format_get_extensions (format);

		for (i = 0; extension_list[i] != 0; i++) {
			if (g_str_has_suffix (uri, extension_list[i])) {
			    	g_slist_free (pixbuf_formats);
				g_strfreev (extension_list);
				return format;
			}
		}
		g_strfreev (extension_list);
	}

	g_slist_free (pixbuf_formats);
	return NULL;
}