/*   PIKA - Photo and Image Kooker Application
 *   Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 *   Quite OK Image (QOI) plug-in
 *
 *   Copyright (C) 2023 Alex S.
 *
 *   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 <string.h>
#include <errno.h>

#include <glib/gstdio.h>

#include <libpika/pika.h>
#include <libpika/pikaui.h>

#define QOI_IMPLEMENTATION
#include "qoi.h"

#include "libpika/stdplugins-intl.h"


#define LOAD_PROC      "file-qoi-load"
#define SAVE_PROC      "file-qoi-save"
#define PLUG_IN_BINARY "file-qoi"
#define PLUG_IN_ROLE   "pika-file-qoi"

typedef struct _Qoi      Qoi;
typedef struct _QoiClass QoiClass;

struct _Qoi
{
  PikaPlugIn      parent_instance;
};

struct _QoiClass
{
  PikaPlugInClass parent_class;
};


#define QOI_TYPE  (qoi_get_type ())
#define QOI(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), QOI_TYPE, Qoi))

GType                   qoi_get_type         (void) G_GNUC_CONST;


static GList          * qoi_query_procedures (PikaPlugIn            *plug_in);
static PikaProcedure  * qoi_create_procedure (PikaPlugIn            *plug_in,
                                              const gchar           *name);

static PikaValueArray * qoi_load             (PikaProcedure         *procedure,
                                              PikaRunMode            run_mode,
                                              GFile                 *file,
                                              PikaMetadata          *metadata,
                                              PikaMetadataLoadFlags *flags,
                                              PikaProcedureConfig   *config,
                                              gpointer               run_data);
static PikaValueArray * qoi_save             (PikaProcedure         *procedure,
                                              PikaRunMode            run_mode,
                                              PikaImage             *image,
                                              gint                   n_drawables,
                                              PikaDrawable         **drawables,
                                              GFile                 *file,
                                              PikaMetadata          *metadata,
                                              PikaProcedureConfig   *config,
                                              gpointer               run_data);

static PikaImage      * load_image           (GFile                 *file,
                                              GObject               *config,
                                              PikaRunMode            run_mode,
                                              GError               **error);
static gboolean         save_image           (GFile                 *file,
                                              PikaImage             *image,
                                              PikaDrawable          *drawable,
                                              GError               **error);


G_DEFINE_TYPE (Qoi, qoi, PIKA_TYPE_PLUG_IN)

PIKA_MAIN (QOI_TYPE)
DEFINE_STD_SET_I18N


static void
qoi_class_init (QoiClass *klass)
{
  PikaPlugInClass *plug_in_class = PIKA_PLUG_IN_CLASS (klass);

  plug_in_class->query_procedures = qoi_query_procedures;
  plug_in_class->create_procedure = qoi_create_procedure;
  plug_in_class->set_i18n         = STD_SET_I18N;
}

static void
qoi_init (Qoi *qoi)
{
}

static GList *
qoi_query_procedures (PikaPlugIn *plug_in)
{
  GList *list = NULL;

  list = g_list_append (list, g_strdup (LOAD_PROC));
  list = g_list_append (list, g_strdup (SAVE_PROC));

  return list;
}

static PikaProcedure *
qoi_create_procedure (PikaPlugIn  *plug_in,
                      const gchar *name)
{
  PikaProcedure *procedure = NULL;

  if (! strcmp (name, LOAD_PROC))
    {
      procedure = pika_load_procedure_new (plug_in, name,
                                           PIKA_PDB_PROC_TYPE_PLUGIN,
                                           qoi_load, NULL, NULL);

      pika_procedure_set_menu_label (procedure,
                                     N_("Quite OK Image"));

      pika_procedure_set_documentation (procedure,
                                        _("Load file in the QOI file format"),
                                        _("Load file in the QOI file format "
                                          "(Quite OK Image)"),
                                        name);
      pika_procedure_set_attribution (procedure,
                                      "Alex S.",
                                      "Alex S.",
                                      "2023");

      pika_file_procedure_set_mime_types (PIKA_FILE_PROCEDURE (procedure),
                                          "image/qoi");
      pika_file_procedure_set_extensions (PIKA_FILE_PROCEDURE (procedure),
                                          "qoi");
      pika_file_procedure_set_magics (PIKA_FILE_PROCEDURE (procedure),
                                      "0,string,qoif");
    }
  else if (! strcmp (name, SAVE_PROC))
    {
      procedure = pika_save_procedure_new (plug_in, name,
                                           PIKA_PDB_PROC_TYPE_PLUGIN,
                                           FALSE, qoi_save, NULL, NULL);

      pika_procedure_set_image_types (procedure, "*");

      pika_procedure_set_menu_label (procedure, _("Quite OK Image"));

      pika_procedure_set_documentation (procedure,
                                        _("Export image in the QOI file format"),
                                        _("Export image in the QOI file format "
                                          "(Quite OK Image)"),
                                        name);
      pika_procedure_set_attribution (procedure,
                                      "Alex S.",
                                      "Alex S.",
                                      "2023");

      pika_file_procedure_set_mime_types (PIKA_FILE_PROCEDURE (procedure),
                                          "image/qoi");
      pika_file_procedure_set_extensions (PIKA_FILE_PROCEDURE (procedure),
                                          "qoi");
    }

  return procedure;
}

static PikaValueArray *
qoi_load (PikaProcedure         *procedure,
          PikaRunMode            run_mode,
          GFile                 *file,
          PikaMetadata          *metadata,
          PikaMetadataLoadFlags *flags,
          PikaProcedureConfig   *config,
          gpointer               run_data)
{
  PikaValueArray *return_vals;
  PikaImage      *image;
  GError         *error = NULL;

  gegl_init (NULL, NULL);

  image = load_image (file, G_OBJECT (config), run_mode, &error);

  if (! image)
    return pika_procedure_new_return_values (procedure,
                                             PIKA_PDB_EXECUTION_ERROR,
                                             error);

  return_vals = pika_procedure_new_return_values (procedure,
                                                  PIKA_PDB_SUCCESS,
                                                  NULL);

  PIKA_VALUES_SET_IMAGE (return_vals, 1, image);

  return return_vals;
}

static PikaValueArray *
qoi_save (PikaProcedure        *procedure,
          PikaRunMode           run_mode,
          PikaImage            *image,
          gint                  n_drawables,
          PikaDrawable        **drawables,
          GFile                *file,
          PikaMetadata         *metadata,
          PikaProcedureConfig  *config,
          gpointer              run_data)
{
  PikaPDBStatusType  status = PIKA_PDB_SUCCESS;
  PikaExportReturn   export = PIKA_EXPORT_CANCEL;
  GError            *error  = NULL;

  gegl_init (NULL, NULL);

  switch (run_mode)
    {
    case PIKA_RUN_INTERACTIVE:
    case PIKA_RUN_WITH_LAST_VALS:
      pika_ui_init (PLUG_IN_BINARY);

      export = pika_export_image (&image, &n_drawables, &drawables, "qoi",
                                  PIKA_EXPORT_CAN_HANDLE_RGB     |
                                  PIKA_EXPORT_CAN_HANDLE_GRAY    |
                                  PIKA_EXPORT_CAN_HANDLE_INDEXED |
                                  PIKA_EXPORT_CAN_HANDLE_ALPHA);

      if (export == PIKA_EXPORT_CANCEL)
        return pika_procedure_new_return_values (procedure,
                                                 PIKA_PDB_CANCEL,
                                                 NULL);
      break;

    default:
      break;
    }

  if (n_drawables != 1)
    {
      g_set_error (&error, G_FILE_ERROR, 0,
                   _("QOI format does not support multiple layers."));

      return pika_procedure_new_return_values (procedure,
                                               PIKA_PDB_CALLING_ERROR,
                                               error);
    }

  if (! save_image (file, image, drawables[0], &error))
    status = PIKA_PDB_EXECUTION_ERROR;

  if (export == PIKA_EXPORT_EXPORT)
    {
      pika_image_delete (image);
      g_free (drawables);
    }

  return pika_procedure_new_return_values (procedure, status, error);
}

static PikaImage *
load_image (GFile        *file,
            GObject      *config,
            PikaRunMode   run_mode,
            GError      **error)
{
  PikaImage  *image  = NULL;
  PikaLayer  *layer;
  GeglBuffer *buffer;
  qoi_desc    desc;
  void       *pixels = NULL;
  const Babl *format = NULL;
  FILE       *fp;

  fp = g_fopen (g_file_peek_path (file), "rb");

  if (! fp)
    {
      g_set_error (error, G_FILE_ERROR, g_file_error_from_errno (errno),
                   _("Could not open '%s' for reading: %s"),
                   pika_file_get_utf8_name (file), g_strerror (errno));
      return NULL;
    }

  fclose (fp);

  pixels = qoi_read (g_file_peek_path (file), &desc, 0);

  if (! pixels)
    {
      g_set_error (error, G_FILE_ERROR, g_file_error_from_errno (errno),
                   _("Failed to read QOI file"));
      return NULL;
    }

  image = pika_image_new_with_precision (desc.width, desc.height, PIKA_RGB,
                                         desc.colorspace ?
                                         PIKA_PRECISION_U8_LINEAR :
                                         PIKA_PRECISION_U8_NON_LINEAR);

  layer = pika_layer_new (image, _("Background"), desc.width, desc.height,
                          (desc.channels == 4) ? PIKA_RGBA_IMAGE : PIKA_RGB_IMAGE,
                          100, pika_image_get_default_new_layer_mode (image));
  pika_image_insert_layer (image, layer, NULL, 0);

  format = babl_format ((desc.channels == 4) ? "R'G'B'A u8" : "R'G'B' u8");

  buffer = pika_drawable_get_buffer (PIKA_DRAWABLE (layer));

  gegl_buffer_set (buffer, GEGL_RECTANGLE (0, 0, desc.width, desc.height), 0,
                   format, pixels, GEGL_AUTO_ROWSTRIDE);

  g_object_unref (buffer);
  g_free (pixels);

  return image;
}

static gboolean
save_image (GFile         *file,
            PikaImage     *image,
            PikaDrawable  *drawable,
            GError       **error)
{
  GeglBuffer *buffer;
  const Babl *format;
  qoi_desc    desc;
  void       *pixels = NULL;
  gboolean    has_alpha;
  gint        success;

  has_alpha = pika_drawable_has_alpha (drawable);

  buffer = pika_drawable_get_buffer (drawable);

  desc.width    = gegl_buffer_get_width  (buffer);
  desc.height   = gegl_buffer_get_height (buffer);
  desc.channels = has_alpha ? 4 : 3;
  switch (pika_image_get_precision (image))
    {
      case PIKA_PRECISION_U8_LINEAR:
      case PIKA_PRECISION_U16_LINEAR:
      case PIKA_PRECISION_U32_LINEAR:
      case PIKA_PRECISION_HALF_LINEAR:
      case PIKA_PRECISION_FLOAT_LINEAR:
      case PIKA_PRECISION_DOUBLE_LINEAR:
        desc.colorspace = QOI_LINEAR;
        break;

      default:
        desc.colorspace = QOI_SRGB;
        break;
    }

  pika_progress_init_printf (_("Exporting '%s'"),
                             pika_file_get_utf8_name (file));

  format = babl_format (has_alpha ? "R'G'B'A u8" : "R'G'B' u8");

  pixels = (guchar *) g_malloc (desc.width * desc.height * desc.channels);

  gegl_buffer_get (buffer, GEGL_RECTANGLE (0, 0, desc.width, desc.height),
                   1.0, format, pixels,
                   GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);

  success = qoi_write (g_file_peek_path (file), pixels, &desc);

  g_object_unref (buffer);
  g_free (pixels);

  if (! success)
    {
      g_set_error (error, G_FILE_ERROR, g_file_error_from_errno (errno),
                   _("Writing to file '%s' failed: %s"),
                   pika_file_get_utf8_name (file), g_strerror (errno));
      return FALSE;
    }

  return TRUE;
}