/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * 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 3 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, see <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gegl.h>

#include "core-types.h"

#include "gegl/gimp-babl.h"

#include "gimperror.h"
#include "gimpimage.h"
#include "gimplayer.h"
#include "gimplayermask.h"

#include "gimp-intl.h"


static void            gimp_layer_mask_preview_freeze       (GimpViewable      *viewable);
static void            gimp_layer_mask_preview_thaw         (GimpViewable      *viewable);

static gboolean        gimp_layer_mask_is_attached          (GimpItem          *item);
static gboolean        gimp_layer_mask_is_content_locked    (GimpItem          *item,
                                                             GimpItem         **locked_item);
static gboolean        gimp_layer_mask_is_position_locked   (GimpItem          *item,
                                                             GimpItem         **locked_item,
                                                             gboolean           check_children);
static GimpItemTree  * gimp_layer_mask_get_tree             (GimpItem          *item);
static GimpItem      * gimp_layer_mask_duplicate            (GimpItem          *item,
                                                             GType              new_type);
static gboolean        gimp_layer_mask_rename               (GimpItem          *item,
                                                             const gchar       *new_name,
                                                             const gchar       *undo_desc,
                                                             GError           **error);

static void            gimp_layer_mask_bounding_box_changed (GimpDrawable      *drawable);
static void            gimp_layer_mask_convert_type         (GimpDrawable      *drawable,
                                                             GimpImage         *dest_image,
                                                             const Babl        *new_format,
                                                             GimpColorProfile  *src_profile,
                                                             GimpColorProfile  *dest_profile,
                                                             GeglDitherMethod   layer_dither_type,
                                                             GeglDitherMethod   mask_dither_type,
                                                             gboolean           push_undo,
                                                             GimpProgress      *progress);


G_DEFINE_TYPE (GimpLayerMask, gimp_layer_mask, GIMP_TYPE_CHANNEL)

#define parent_class gimp_layer_mask_parent_class


static void
gimp_layer_mask_class_init (GimpLayerMaskClass *klass)
{
  GimpViewableClass *viewable_class = GIMP_VIEWABLE_CLASS (klass);
  GimpItemClass     *item_class     = GIMP_ITEM_CLASS (klass);
  GimpDrawableClass *drawable_class = GIMP_DRAWABLE_CLASS (klass);

  viewable_class->default_icon_name = "gimp-layer-mask";

  viewable_class->preview_freeze       = gimp_layer_mask_preview_freeze;
  viewable_class->preview_thaw         = gimp_layer_mask_preview_thaw;

  item_class->is_attached              = gimp_layer_mask_is_attached;
  item_class->is_content_locked        = gimp_layer_mask_is_content_locked;
  item_class->is_position_locked       = gimp_layer_mask_is_position_locked;
  item_class->get_tree                 = gimp_layer_mask_get_tree;
  item_class->duplicate                = gimp_layer_mask_duplicate;
  item_class->rename                   = gimp_layer_mask_rename;
  item_class->translate_desc           = C_("undo-type", "Move Layer Mask");
  item_class->to_selection_desc        = C_("undo-type", "Layer Mask to Selection");

  drawable_class->bounding_box_changed = gimp_layer_mask_bounding_box_changed;
  drawable_class->convert_type         = gimp_layer_mask_convert_type;
}

static void
gimp_layer_mask_init (GimpLayerMask *layer_mask)
{
  layer_mask->layer = NULL;
}

static void
gimp_layer_mask_preview_freeze (GimpViewable *viewable)
{
  GimpLayerMask *mask  = GIMP_LAYER_MASK (viewable);
  GimpLayer     *layer = gimp_layer_mask_get_layer (mask);

  if (layer)
    {
      GimpViewable *parent = gimp_viewable_get_parent (GIMP_VIEWABLE (layer));

      if (! parent && gimp_item_is_attached (GIMP_ITEM (layer)))
        parent = GIMP_VIEWABLE (gimp_item_get_image (GIMP_ITEM (layer)));

      if (parent)
        gimp_viewable_preview_freeze (parent);
    }
}

static void
gimp_layer_mask_preview_thaw (GimpViewable *viewable)
{
  GimpLayerMask *mask  = GIMP_LAYER_MASK (viewable);
  GimpLayer     *layer = gimp_layer_mask_get_layer (mask);

  if (layer)
    {
      GimpViewable *parent = gimp_viewable_get_parent (GIMP_VIEWABLE (layer));

      if (! parent && gimp_item_is_attached (GIMP_ITEM (layer)))
        parent = GIMP_VIEWABLE (gimp_item_get_image (GIMP_ITEM (layer)));

      if (parent)
        gimp_viewable_preview_thaw (parent);
    }
}

static gboolean
gimp_layer_mask_is_content_locked (GimpItem  *item,
                                   GimpItem **locked_item)
{
  GimpLayerMask *mask  = GIMP_LAYER_MASK (item);
  GimpLayer     *layer = gimp_layer_mask_get_layer (mask);

  if (layer)
    return gimp_item_is_content_locked (GIMP_ITEM (layer), locked_item);

  return FALSE;
}

static gboolean
gimp_layer_mask_is_position_locked (GimpItem  *item,
                                    GimpItem **locked_item,
                                    gboolean   check_children)
{
  GimpLayerMask *mask  = GIMP_LAYER_MASK (item);
  GimpLayer     *layer = gimp_layer_mask_get_layer (mask);

  if (layer)
    return gimp_item_is_position_locked (GIMP_ITEM (layer), locked_item);

  return FALSE;
}

static gboolean
gimp_layer_mask_is_attached (GimpItem *item)
{
  GimpLayerMask *mask  = GIMP_LAYER_MASK (item);
  GimpLayer     *layer = gimp_layer_mask_get_layer (mask);

  return (GIMP_IS_IMAGE (gimp_item_get_image (item)) &&
          GIMP_IS_LAYER (layer)                      &&
          gimp_layer_get_mask (layer) == mask        &&
          gimp_item_is_attached (GIMP_ITEM (layer)));
}

static GimpItemTree *
gimp_layer_mask_get_tree (GimpItem *item)
{
  return NULL;
}

static GimpItem *
gimp_layer_mask_duplicate (GimpItem *item,
                           GType     new_type)
{
  GimpItem *new_item;

  g_return_val_if_fail (g_type_is_a (new_type, GIMP_TYPE_DRAWABLE), NULL);

  new_item = GIMP_ITEM_CLASS (parent_class)->duplicate (item, new_type);

  return new_item;
}

static gboolean
gimp_layer_mask_rename (GimpItem     *item,
                        const gchar  *new_name,
                        const gchar  *undo_desc,
                        GError      **error)
{
  /* reject renaming, layer masks are always named "<layer name> mask"  */

  g_set_error (error, GIMP_ERROR, GIMP_FAILED,
               _("Cannot rename layer masks."));

  return FALSE;
}

static void
gimp_layer_mask_bounding_box_changed (GimpDrawable *drawable)
{
  GimpLayerMask *mask  = GIMP_LAYER_MASK (drawable);
  GimpLayer     *layer = gimp_layer_mask_get_layer (mask);

  if (GIMP_DRAWABLE_CLASS (parent_class)->bounding_box_changed)
    GIMP_DRAWABLE_CLASS (parent_class)->bounding_box_changed (drawable);

  if (layer)
    gimp_drawable_update_bounding_box (GIMP_DRAWABLE (layer));
}

static void
gimp_layer_mask_convert_type (GimpDrawable      *drawable,
                              GimpImage         *dest_image,
                              const Babl        *new_format,
                              GimpColorProfile  *src_profile,
                              GimpColorProfile  *dest_profile,
                              GeglDitherMethod   layer_dither_type,
                              GeglDitherMethod   mask_dither_type,
                              gboolean           push_undo,
                              GimpProgress      *progress)
{
  new_format =
    gimp_babl_mask_format (gimp_babl_format_get_precision (new_format));

  GIMP_DRAWABLE_CLASS (parent_class)->convert_type (drawable, dest_image,
                                                    new_format,
                                                    src_profile,
                                                    dest_profile,
                                                    layer_dither_type,
                                                    mask_dither_type,
                                                    push_undo,
                                                    progress);
}

GimpLayerMask *
gimp_layer_mask_new (GimpImage     *image,
                     gint           width,
                     gint           height,
                     const gchar   *name,
                     const GimpRGB *color)
{
  GimpLayerMask *layer_mask;

  g_return_val_if_fail (GIMP_IS_IMAGE (image), NULL);
  g_return_val_if_fail (width > 0, NULL);
  g_return_val_if_fail (height > 0, NULL);
  g_return_val_if_fail (color != NULL, NULL);

  layer_mask =
    GIMP_LAYER_MASK (gimp_drawable_new (GIMP_TYPE_LAYER_MASK,
                                        image, name,
                                        0, 0, width, height,
                                        gimp_image_get_mask_format (image)));

  /*  set the layer_mask color and opacity  */
  gimp_channel_set_color (GIMP_CHANNEL (layer_mask), color, FALSE);
  gimp_channel_set_show_masked (GIMP_CHANNEL (layer_mask), TRUE);

  /*  selection mask variables  */
  GIMP_CHANNEL (layer_mask)->x2 = width;
  GIMP_CHANNEL (layer_mask)->y2 = height;

  return layer_mask;
}

void
gimp_layer_mask_set_layer (GimpLayerMask *layer_mask,
                           GimpLayer     *layer)
{
  g_return_if_fail (GIMP_IS_LAYER_MASK (layer_mask));
  g_return_if_fail (layer == NULL || GIMP_IS_LAYER (layer));

  layer_mask->layer = layer;

  if (layer)
    {
      gchar *mask_name;
      gint   offset_x;
      gint   offset_y;

      gimp_item_get_offset (GIMP_ITEM (layer), &offset_x, &offset_y);
      gimp_item_set_offset (GIMP_ITEM (layer_mask), offset_x, offset_y);

      mask_name = g_strdup_printf (_("%s mask"), gimp_object_get_name (layer));

      gimp_object_take_name (GIMP_OBJECT (layer_mask), mask_name);
    }
}

GimpLayer *
gimp_layer_mask_get_layer (GimpLayerMask *layer_mask)
{
  g_return_val_if_fail (GIMP_IS_LAYER_MASK (layer_mask), NULL);

  return layer_mask->layer;
}