/* PIKA - Photo and Image Kooker Application
 * a rebranding of The GNU Image Manipulation Program (created with heckimp)
 * A derived work which may be trivial. However, any changes may be (C)2023 by Aldercone Studio
 *
 * Original copyright, applying to most contents (license remains unchanged): 
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * pikaplugin-cleanup.c
 *
 * 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 "plug-in-types.h"

#include "core/pika.h"
#include "core/pikacontainer.h"
#include "core/pikadrawable.h"
#include "core/pikadrawable-shadow.h"
#include "core/pikaimage.h"
#include "core/pikaimage-undo.h"
#include "core/pikaundostack.h"

#include "pikaplugin.h"
#include "pikaplugin-cleanup.h"
#include "pikapluginmanager.h"
#include "pikapluginprocedure.h"

#include "pika-log.h"


typedef struct _PikaPlugInCleanupImage PikaPlugInCleanupImage;

struct _PikaPlugInCleanupImage
{
  PikaImage *image;
  gint       image_id;

  gint       undo_group_count;
  gint       layers_freeze_count;
  gint       channels_freeze_count;
  gint       vectors_freeze_count;
};


typedef struct _PikaPlugInCleanupItem PikaPlugInCleanupItem;

struct _PikaPlugInCleanupItem
{
  PikaItem *item;
  gint      item_id;

  gboolean  shadow_buffer;
};


/*  local function prototypes  */

static PikaPlugInCleanupImage *
              pika_plug_in_cleanup_image_new      (PikaPlugInProcFrame    *proc_frame,
                                                   PikaImage              *image);
static void   pika_plug_in_cleanup_image_free     (PikaPlugInProcFrame    *proc_frame,
                                                   PikaPlugInCleanupImage *cleanup);
static gboolean
              pika_plug_in_cleanup_image_is_clean (PikaPlugInCleanupImage *cleanup);
static PikaPlugInCleanupImage *
              pika_plug_in_cleanup_image_get      (PikaPlugInProcFrame    *proc_frame,
                                                   PikaImage              *image);
static void   pika_plug_in_cleanup_image          (PikaPlugInProcFrame    *proc_frame,
                                                   PikaPlugInCleanupImage *cleanup);

static PikaPlugInCleanupItem *
              pika_plug_in_cleanup_item_new       (PikaPlugInProcFrame    *proc_frame,
                                                   PikaItem               *item);
static void   pika_plug_in_cleanup_item_free      (PikaPlugInProcFrame    *proc_frame,
                                                   PikaPlugInCleanupItem  *cleanup);
static gboolean
              pika_plug_in_cleanup_item_is_clean  (PikaPlugInCleanupItem  *cleanup);
static PikaPlugInCleanupItem *
              pika_plug_in_cleanup_item_get       (PikaPlugInProcFrame    *proc_frame,
                                                   PikaItem               *item);
static void   pika_plug_in_cleanup_item           (PikaPlugInProcFrame    *proc_frame,
                                                   PikaPlugInCleanupItem  *cleanup);


/*  public functions  */

gboolean
pika_plug_in_cleanup_undo_group_start (PikaPlugIn *plug_in,
                                       PikaImage  *image)
{
  PikaPlugInProcFrame    *proc_frame;
  PikaPlugInCleanupImage *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_IMAGE (image), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_image_get (proc_frame, image);

  if (! cleanup)
    cleanup = pika_plug_in_cleanup_image_new (proc_frame, image);

  cleanup->undo_group_count++;

  return TRUE;
}

gboolean
pika_plug_in_cleanup_undo_group_end (PikaPlugIn *plug_in,
                                     PikaImage  *image)
{
  PikaPlugInProcFrame    *proc_frame;
  PikaPlugInCleanupImage *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_IMAGE (image), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_image_get (proc_frame, image);

  if (! cleanup)
    return FALSE;

  if (cleanup->undo_group_count > 0)
    {
      cleanup->undo_group_count--;

      if (pika_plug_in_cleanup_image_is_clean (cleanup))
        pika_plug_in_cleanup_image_free (proc_frame, cleanup);

      return TRUE;
    }

  return FALSE;
}

gboolean
pika_plug_in_cleanup_layers_freeze (PikaPlugIn *plug_in,
                                    PikaImage  *image)
{
  PikaPlugInProcFrame    *proc_frame;
  PikaPlugInCleanupImage *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_IMAGE (image), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_image_get (proc_frame, image);

  if (! cleanup)
    cleanup = pika_plug_in_cleanup_image_new (proc_frame, image);

  cleanup->layers_freeze_count++;

  return TRUE;
}

gboolean
pika_plug_in_cleanup_layers_thaw (PikaPlugIn *plug_in,
                                  PikaImage  *image)
{
  PikaPlugInProcFrame    *proc_frame;
  PikaPlugInCleanupImage *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_IMAGE (image), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_image_get (proc_frame, image);

  if (! cleanup)
    return FALSE;

  if (cleanup->layers_freeze_count > 0)
    {
      cleanup->layers_freeze_count--;

      if (pika_plug_in_cleanup_image_is_clean (cleanup))
        pika_plug_in_cleanup_image_free (proc_frame, cleanup);

      return TRUE;
    }

  return FALSE;
}

gboolean
pika_plug_in_cleanup_channels_freeze (PikaPlugIn *plug_in,
                                      PikaImage  *image)
{
  PikaPlugInProcFrame    *proc_frame;
  PikaPlugInCleanupImage *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_IMAGE (image), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_image_get (proc_frame, image);

  if (! cleanup)
    cleanup = pika_plug_in_cleanup_image_new (proc_frame, image);

  cleanup->channels_freeze_count++;

  return TRUE;
}

gboolean
pika_plug_in_cleanup_channels_thaw (PikaPlugIn *plug_in,
                                    PikaImage  *image)
{
  PikaPlugInProcFrame    *proc_frame;
  PikaPlugInCleanupImage *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_IMAGE (image), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_image_get (proc_frame, image);

  if (! cleanup)
    return FALSE;

  if (cleanup->channels_freeze_count > 0)
    {
      cleanup->channels_freeze_count--;

      if (pika_plug_in_cleanup_image_is_clean (cleanup))
        pika_plug_in_cleanup_image_free (proc_frame, cleanup);

      return TRUE;
    }

  return FALSE;
}

gboolean
pika_plug_in_cleanup_vectors_freeze (PikaPlugIn *plug_in,
                                     PikaImage  *image)
{
  PikaPlugInProcFrame    *proc_frame;
  PikaPlugInCleanupImage *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_IMAGE (image), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_image_get (proc_frame, image);

  if (! cleanup)
    cleanup = pika_plug_in_cleanup_image_new (proc_frame, image);

  cleanup->vectors_freeze_count++;

  return TRUE;
}

gboolean
pika_plug_in_cleanup_vectors_thaw (PikaPlugIn *plug_in,
                                   PikaImage  *image)
{
  PikaPlugInProcFrame    *proc_frame;
  PikaPlugInCleanupImage *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_IMAGE (image), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_image_get (proc_frame, image);

  if (! cleanup)
    return FALSE;

  if (cleanup->vectors_freeze_count > 0)
    {
      cleanup->vectors_freeze_count--;

      if (pika_plug_in_cleanup_image_is_clean (cleanup))
        pika_plug_in_cleanup_image_free (proc_frame, cleanup);

      return TRUE;
    }

  return FALSE;
}

gboolean
pika_plug_in_cleanup_add_shadow (PikaPlugIn   *plug_in,
                                 PikaDrawable *drawable)
{
  PikaPlugInProcFrame   *proc_frame;
  PikaPlugInCleanupItem *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_DRAWABLE (drawable), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_item_get (proc_frame, PIKA_ITEM (drawable));

  if (! cleanup)
    cleanup = pika_plug_in_cleanup_item_new (proc_frame, PIKA_ITEM (drawable));

  cleanup->shadow_buffer = TRUE;

  return TRUE;
}

gboolean
pika_plug_in_cleanup_remove_shadow (PikaPlugIn   *plug_in,
                                    PikaDrawable *drawable)
{
  PikaPlugInProcFrame   *proc_frame;
  PikaPlugInCleanupItem *cleanup;

  g_return_val_if_fail (PIKA_IS_PLUG_IN (plug_in), FALSE);
  g_return_val_if_fail (PIKA_IS_DRAWABLE (drawable), FALSE);

  proc_frame = pika_plug_in_get_proc_frame (plug_in);
  cleanup    = pika_plug_in_cleanup_item_get (proc_frame, PIKA_ITEM (drawable));

  if (! cleanup)
    return FALSE;

  if (cleanup->shadow_buffer)
    {
      cleanup->shadow_buffer = FALSE;

      if (pika_plug_in_cleanup_item_is_clean (cleanup))
        pika_plug_in_cleanup_item_free (proc_frame, cleanup);

      return TRUE;
    }

  return FALSE;
}

void
pika_plug_in_cleanup (PikaPlugIn          *plug_in,
                      PikaPlugInProcFrame *proc_frame)
{
  g_return_if_fail (PIKA_IS_PLUG_IN (plug_in));
  g_return_if_fail (proc_frame != NULL);

  while (proc_frame->image_cleanups)
    {
      PikaPlugInCleanupImage *cleanup = proc_frame->image_cleanups->data;

      if (pika_image_get_by_id (plug_in->manager->pika,
                                cleanup->image_id) == cleanup->image)
        {
          pika_plug_in_cleanup_image (proc_frame, cleanup);
        }

      pika_plug_in_cleanup_image_free (proc_frame, cleanup);
    }

  while (proc_frame->item_cleanups)
    {
      PikaPlugInCleanupItem *cleanup = proc_frame->item_cleanups->data;

      if (pika_item_get_by_id (plug_in->manager->pika,
                               cleanup->item_id) == cleanup->item)
        {
          pika_plug_in_cleanup_item (proc_frame, cleanup);
        }

      pika_plug_in_cleanup_item_free (proc_frame, cleanup);
    }
}


/*  private functions  */

static PikaPlugInCleanupImage *
pika_plug_in_cleanup_image_new (PikaPlugInProcFrame *proc_frame,
                                PikaImage           *image)
{
  PikaPlugInCleanupImage *cleanup = g_slice_new0 (PikaPlugInCleanupImage);

  cleanup->image    = image;
  cleanup->image_id = pika_image_get_id (image);

  proc_frame->image_cleanups = g_list_prepend (proc_frame->image_cleanups,
                                               cleanup);

  return cleanup;
}

static void
pika_plug_in_cleanup_image_free (PikaPlugInProcFrame    *proc_frame,
                                 PikaPlugInCleanupImage *cleanup)
{
  proc_frame->image_cleanups = g_list_remove (proc_frame->image_cleanups,
                                              cleanup);

  g_slice_free (PikaPlugInCleanupImage, cleanup);
}

static gboolean
pika_plug_in_cleanup_image_is_clean (PikaPlugInCleanupImage *cleanup)
{
  if (cleanup->undo_group_count > 0)
    return FALSE;

  if (cleanup->layers_freeze_count > 0)
    return FALSE;

  if (cleanup->channels_freeze_count > 0)
    return FALSE;

  if (cleanup->vectors_freeze_count > 0)
    return FALSE;

  return TRUE;
}

static PikaPlugInCleanupImage *
pika_plug_in_cleanup_image_get (PikaPlugInProcFrame *proc_frame,
                                PikaImage           *image)
{
  GList *list;

  for (list = proc_frame->image_cleanups; list; list = g_list_next (list))
    {
      PikaPlugInCleanupImage *cleanup = list->data;

      if (cleanup->image == image)
        return cleanup;
    }

  return NULL;
}

static void
pika_plug_in_cleanup_image (PikaPlugInProcFrame    *proc_frame,
                            PikaPlugInCleanupImage *cleanup)
{
  PikaImage     *image = cleanup->image;
  PikaContainer *container;

  if (cleanup->undo_group_count > 0)
    {
      g_message ("Plug-in '%s' left image undo in inconsistent state, "
                 "closing open undo groups.",
                 pika_procedure_get_label (proc_frame->procedure));

      while (cleanup->undo_group_count--)
        if (! pika_image_undo_group_end (image))
          break;
    }

  container = pika_image_get_layers (image);

  if (cleanup->layers_freeze_count > 0)
    {
      g_message ("Plug-in '%s' left image's layers frozen, "
                 "thawing layers.",
                 pika_procedure_get_label (proc_frame->procedure));

      while (cleanup->layers_freeze_count-- > 0 &&
             pika_container_frozen (container))
        {
          pika_container_thaw (container);
        }
    }

  container = pika_image_get_channels (image);

  if (cleanup->channels_freeze_count > 0)
    {
      g_message ("Plug-in '%s' left image's channels frozen, "
                 "thawing channels.",
                 pika_procedure_get_label (proc_frame->procedure));

      while (cleanup->channels_freeze_count-- > 0 &&
             pika_container_frozen (container))
        {
          pika_container_thaw (container);
        }
    }

  container = pika_image_get_vectors (image);

  if (cleanup->vectors_freeze_count > 0)
    {
      g_message ("Plug-in '%s' left image's vectors frozen, "
                 "thawing vectors.",
                 pika_procedure_get_label (proc_frame->procedure));

      while (cleanup->vectors_freeze_count > 0 &&
             pika_container_frozen (container))
        {
          pika_container_thaw (container);
        }
    }
}

static PikaPlugInCleanupItem *
pika_plug_in_cleanup_item_new (PikaPlugInProcFrame *proc_frame,
                               PikaItem            *item)
{
  PikaPlugInCleanupItem *cleanup = g_slice_new0 (PikaPlugInCleanupItem);

  cleanup->item    = item;
  cleanup->item_id = pika_item_get_id (item);

  proc_frame->item_cleanups = g_list_prepend (proc_frame->item_cleanups,
                                              cleanup);

  return cleanup;
}

static void
pika_plug_in_cleanup_item_free (PikaPlugInProcFrame   *proc_frame,
                                PikaPlugInCleanupItem *cleanup)
{
  proc_frame->item_cleanups = g_list_remove (proc_frame->item_cleanups,
                                             cleanup);

  g_slice_free (PikaPlugInCleanupItem, cleanup);
}

static gboolean
pika_plug_in_cleanup_item_is_clean (PikaPlugInCleanupItem *cleanup)
{
  if (cleanup->shadow_buffer)
    return FALSE;

  return TRUE;
}

static PikaPlugInCleanupItem *
pika_plug_in_cleanup_item_get (PikaPlugInProcFrame *proc_frame,
                               PikaItem            *item)
{
  GList *list;

  for (list = proc_frame->item_cleanups; list; list = g_list_next (list))
    {
      PikaPlugInCleanupItem *cleanup = list->data;

      if (cleanup->item == item)
        return cleanup;
    }

  return NULL;
}

static void
pika_plug_in_cleanup_item (PikaPlugInProcFrame   *proc_frame,
                           PikaPlugInCleanupItem *cleanup)
{
  PikaItem *item = cleanup->item;

  if (cleanup->shadow_buffer)
    {
      PIKA_LOG (SHADOW_TILES,
                "Freeing shadow buffer of drawable '%s' on behalf of '%s'.",
                pika_object_get_name (item),
                pika_procedure_get_label (proc_frame->procedure));

      pika_drawable_free_shadow_buffer (PIKA_DRAWABLE (item));

      cleanup->shadow_buffer = FALSE;
    }
}