/*
 * Copyright © 2012 Red Hat Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library. If not, see <http://www.gnu.org/licenses/>.
 *
 * Authors: Benjamin Otte <otte@gnome.org>
 */

#include "config.h"

#include "gtkcssimageiconthemeprivate.h"

#include <math.h>

#include "gtkcssiconthemevalueprivate.h"
#include "gtksettingsprivate.h"
#include "gtksnapshot.h"
#include "gtkstyleproviderprivate.h"
#include "gtkiconthemeprivate.h"

G_DEFINE_TYPE (GtkCssImageIconTheme, _gtk_css_image_icon_theme, GTK_TYPE_CSS_IMAGE)

static double
gtk_css_image_icon_theme_get_aspect_ratio (GtkCssImage *image)
{
  /* icon theme icons only take a single size when requesting, so we insist on being square */
  return 1.0;
}

static void
gtk_css_image_icon_theme_snapshot (GtkCssImage *image,
                                   GtkSnapshot *snapshot,
                                   double       width,
                                   double       height)
{
  GtkCssImageIconTheme *icon_theme = GTK_CSS_IMAGE_ICON_THEME (image);
  GdkTexture *texture;
  double texture_width, texture_height;
  gint size;
  gboolean symbolic;

  size = floor (MIN (width, height));
  if (size <= 0)
    return;

  if (size == icon_theme->cached_size &&
      icon_theme->cached_texture != NULL)
    {
      texture = icon_theme->cached_texture;
      symbolic = icon_theme->cached_symbolic;
    }
  else
    {
      GtkIconInfo *icon_info;

      icon_info = gtk_icon_theme_lookup_icon_for_scale (icon_theme->icon_theme,
                                                        icon_theme->name,
                                                        size,
                                                        icon_theme->scale,
                                                        GTK_ICON_LOOKUP_USE_BUILTIN);
      if (icon_info == NULL)
        icon_info = gtk_icon_theme_lookup_icon (icon_theme->icon_theme,
                                                "image-missing",
                                                size,
                                                GTK_ICON_LOOKUP_USE_BUILTIN | GTK_ICON_LOOKUP_GENERIC_FALLBACK);

      g_assert (icon_info != NULL);

      symbolic = gtk_icon_info_is_symbolic (icon_info);
      texture = GDK_TEXTURE (gtk_icon_info_load_icon (icon_info, NULL));

      g_clear_object (&icon_theme->cached_texture);

      icon_theme->cached_size = size;
      icon_theme->cached_texture = texture;
      icon_theme->cached_symbolic = symbolic;

      g_object_unref (icon_info);
    }

  texture_width = (double) gdk_texture_get_width (texture) / icon_theme->scale;
  texture_height = (double) gdk_texture_get_height (texture) / icon_theme->scale;

  if (symbolic)
    {
      const GdkRGBA *fg = &icon_theme->color;
      const GdkRGBA *sc = &icon_theme->success;
      const GdkRGBA *wc = &icon_theme->warning;
      const GdkRGBA *ec = &icon_theme->error;
      graphene_matrix_t matrix;
      graphene_vec4_t offset;


      graphene_matrix_init_from_float (&matrix,
          (float[16]) {
                       sc->red - fg->red, sc->green - fg->green, sc->blue - fg->blue, 0,
                       wc->red - fg->red, wc->green - fg->green, wc->blue - fg->blue, 0,
                       ec->red - fg->red, ec->green - fg->green, ec->blue - fg->blue, 0,
                       0, 0, 0, fg->alpha
                      });
      graphene_vec4_init (&offset, fg->red, fg->green, fg->blue, 0);

      gtk_snapshot_push_color_matrix (snapshot, &matrix, &offset);
    }

  gtk_snapshot_append_texture (snapshot,
                               texture,
                               &GRAPHENE_RECT_INIT(
                                   (width - texture_width) / 2.0,
                                   (height - texture_height) / 2.0,
                                   texture_width,
                                   texture_height
                               ));
  if (symbolic)
    gtk_snapshot_pop (snapshot);
}

static guint
gtk_css_image_icon_theme_parse_arg (GtkCssParser *parser,
                                    guint         arg,
                                    gpointer      data)
{
  GtkCssImageIconTheme *icon_theme = data;

  icon_theme->name = gtk_css_parser_consume_string (parser);
  if (icon_theme->name == NULL)
    return 0;

  return 1;
}

static gboolean
gtk_css_image_icon_theme_parse (GtkCssImage  *image,
                                GtkCssParser *parser)
{
  if (!gtk_css_parser_has_function (parser, "-gtk-icontheme"))
    {
      gtk_css_parser_error_syntax (parser, "Expected '-gtk-icontheme('");
      return FALSE;
    }

  return gtk_css_parser_consume_function (parser, 1, 1, gtk_css_image_icon_theme_parse_arg, image);
}

static void
gtk_css_image_icon_theme_print (GtkCssImage *image,
                                GString     *string)
{
  GtkCssImageIconTheme *icon_theme = GTK_CSS_IMAGE_ICON_THEME (image);

  g_string_append (string, "-gtk-icontheme(");
  _gtk_css_print_string (string, icon_theme->name);
  g_string_append (string, ")");
}

static GtkCssImage *
gtk_css_image_icon_theme_compute (GtkCssImage      *image,
                                  guint             property_id,
                                  GtkStyleProvider *provider,
                                  GtkCssStyle      *style,
                                  GtkCssStyle      *parent_style)
{
  GtkCssImageIconTheme *icon_theme = GTK_CSS_IMAGE_ICON_THEME (image);
  GtkCssImageIconTheme *copy;

  copy = g_object_new (GTK_TYPE_CSS_IMAGE_ICON_THEME, NULL);
  copy->name = g_strdup (icon_theme->name);
  copy->icon_theme = gtk_css_icon_theme_value_get_icon_theme (style->core->icon_theme);
  copy->scale = gtk_style_provider_get_scale (provider);
  gtk_icon_theme_lookup_symbolic_colors (style, &copy->color, &copy->success, &copy->warning, &copy->error);

  return GTK_CSS_IMAGE (copy);
}

static gboolean
gtk_css_image_icon_theme_equal (GtkCssImage *image1,
                                GtkCssImage *image2)
{
  GtkCssImageIconTheme *icon_theme1 = (GtkCssImageIconTheme *) image1;
  GtkCssImageIconTheme *icon_theme2 = (GtkCssImageIconTheme *) image2;

  return g_str_equal (icon_theme1->name, icon_theme2->name);
}

static void
gtk_css_image_icon_theme_dispose (GObject *object)
{
  GtkCssImageIconTheme *icon_theme = GTK_CSS_IMAGE_ICON_THEME (object);

  g_free (icon_theme->name);
  icon_theme->name = NULL;

  g_clear_object (&icon_theme->cached_texture);

  G_OBJECT_CLASS (_gtk_css_image_icon_theme_parent_class)->dispose (object);
}

static void
_gtk_css_image_icon_theme_class_init (GtkCssImageIconThemeClass *klass)
{
  GtkCssImageClass *image_class = GTK_CSS_IMAGE_CLASS (klass);
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  image_class->get_aspect_ratio = gtk_css_image_icon_theme_get_aspect_ratio;
  image_class->snapshot = gtk_css_image_icon_theme_snapshot;
  image_class->parse = gtk_css_image_icon_theme_parse;
  image_class->print = gtk_css_image_icon_theme_print;
  image_class->compute = gtk_css_image_icon_theme_compute;
  image_class->equal = gtk_css_image_icon_theme_equal;

  object_class->dispose = gtk_css_image_icon_theme_dispose;
}

static void
_gtk_css_image_icon_theme_init (GtkCssImageIconTheme *icon_theme)
{
  icon_theme->icon_theme = gtk_icon_theme_get_default ();
  icon_theme->scale = 1;
  icon_theme->cached_size = -1;
  icon_theme->cached_texture = NULL;
}