/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 * Alias|Wavefront pix/matte image reading and writing code
 * Copyright (C) 1997 Mike Taylor
 * (email: mtaylor@aw.sgi.com, WWW: http://reality.sgi.com/mtaylor)
 *
 * 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/>.
 *
 */

/* This plug-in was written using the online documentation from
 * Alias|Wavefront Inc's PowerAnimator product.
 *
 * Bug reports or suggestions should be e-mailed to mtaylor@aw.sgi.com
 */

/* Event history:
 * V 1.0, MT, 02-Jul-97: initial version of plug-in
 * V 1.1, MT, 04-Dec-97: added .als file extension
 */

/* Features
 *  - loads and exports
 *    - 24-bit (.pix)
 *    - 8-bit (.matte, .alpha, or .mask) images
 *
 * NOTE: pix and matte files do not support alpha channels or indexed
 *       color, so neither does this plug-in
 */

#include "config.h"

#include <errno.h>
#include <string.h>

#include <glib/gstdio.h>

#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>

#include "libgimp/stdplugins-intl.h"


#define LOAD_PROC      "file-pix-load"
#define EXPORT_PROC    "file-pix-export"
#define PLUG_IN_BINARY "file-pix"
#define PLUG_IN_ROLE   "gimp-file-pix"


/* #define PIX_DEBUG */

#ifdef PIX_DEBUG
#    define PIX_DEBUG_PRINT(a,b) g_printerr (a,b)
#else
#    define PIX_DEBUG_PRINT(a,b)
#endif


typedef struct _Pix      Pix;
typedef struct _PixClass PixClass;

struct _Pix
{
  GimpPlugIn      parent_instance;
};

struct _PixClass
{
  GimpPlugInClass parent_class;
};


#define PIX_TYPE  (pix_get_type ())
#define PIX(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), PIX_TYPE, Pix))

GType                   pix_get_type         (void) G_GNUC_CONST;

static GList          * pix_query_procedures (GimpPlugIn            *plug_in);
static GimpProcedure  * pix_create_procedure (GimpPlugIn            *plug_in,
                                              const gchar           *name);

static GimpValueArray * pix_load             (GimpProcedure         *procedure,
                                              GimpRunMode            run_mode,
                                              GFile                 *file,
                                              GimpMetadata          *metadata,
                                              GimpMetadataLoadFlags *flags,
                                              GimpProcedureConfig   *config,
                                              gpointer               run_data);
static GimpValueArray * pix_export           (GimpProcedure         *procedure,
                                              GimpRunMode            run_mode,
                                              GimpImage             *image,
                                              GFile                 *file,
                                              GimpExportOptions     *options,
                                              GimpMetadata          *metadata,
                                              GimpProcedureConfig   *config,
                                              gpointer               run_data);

static GimpImage      * load_image           (GFile                 *file,
                                              GError               **error);
static GimpImage      * load_esm_image       (GInputStream          *input,
                                              GError               **error);
static gboolean         export_image         (GFile                 *file,
                                              GimpImage             *image,
                                              GimpDrawable          *drawable,
                                              GError               **error);

static gboolean         get_short            (GInputStream          *input,
                                              guint16               *value,
                                              GError               **error);
static gboolean         put_short            (GOutputStream         *output,
                                              guint16                value,
                                              GError               **error);


G_DEFINE_TYPE (Pix, pix, GIMP_TYPE_PLUG_IN)

GIMP_MAIN (PIX_TYPE)
DEFINE_STD_SET_I18N


static void
pix_class_init (PixClass *klass)
{
  GimpPlugInClass *plug_in_class = GIMP_PLUG_IN_CLASS (klass);

  plug_in_class->query_procedures = pix_query_procedures;
  plug_in_class->create_procedure = pix_create_procedure;
  plug_in_class->set_i18n         = STD_SET_I18N;
}

static void
pix_init (Pix *pix)
{
}

static GList *
pix_query_procedures (GimpPlugIn *plug_in)
{
  GList *list = NULL;

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

  return list;
}

static GimpProcedure *
pix_create_procedure (GimpPlugIn  *plug_in,
                      const gchar *name)
{
  GimpProcedure *procedure = NULL;

  if (! strcmp (name, LOAD_PROC))
    {
      procedure = gimp_load_procedure_new (plug_in, name,
                                           GIMP_PDB_PROC_TYPE_PLUGIN,
                                           pix_load, NULL, NULL);

      gimp_file_procedure_set_handles_remote (GIMP_FILE_PROCEDURE (procedure),
                                              TRUE);

      gimp_procedure_set_menu_label (procedure, _("Alias Pix image"));

      gimp_procedure_set_documentation (procedure,
                                        _("Loads files of the Alias|Wavefront "
                                          "or Esm Software Pix file format"),
                                        _("Loads files of the Alias|Wavefront "
                                          "or Esm Software Pix file format"),
                                        name);
      gimp_procedure_set_attribution (procedure,
                                      "Michael Taylor",
                                      "Michael Taylor",
                                      "1997");

      gimp_file_procedure_set_extensions (GIMP_FILE_PROCEDURE (procedure),
                                          "pix,matte,mask,alpha,als");
      /* Magic Number for Esm Software PIX files */
      gimp_file_procedure_set_magics (GIMP_FILE_PROCEDURE (procedure),
                                      "0,string,Esm Software PIX file");

    }
  else if (! strcmp (name, EXPORT_PROC))
    {
      procedure = gimp_export_procedure_new (plug_in, name,
                                             GIMP_PDB_PROC_TYPE_PLUGIN,
                                             FALSE, pix_export, NULL, NULL);

      gimp_procedure_set_image_types (procedure, "*");

      gimp_file_procedure_set_handles_remote (GIMP_FILE_PROCEDURE (procedure),
                                              TRUE);

      gimp_procedure_set_menu_label (procedure, _("Alias Pix image"));

      gimp_procedure_set_documentation (procedure,
                                        _("Export file in the Alias|Wavefront "
                                          "pix/matte file format"),
                                        _("Export file in the Alias|Wavefront "
                                          "pix/matte file format"),
                                        name);
      gimp_procedure_set_attribution (procedure,
                                      "Michael Taylor",
                                      "Michael Taylor",
                                      "1997");

      gimp_file_procedure_set_extensions (GIMP_FILE_PROCEDURE (procedure),
                                          "pix,matte,mask,alpha,als");

      gimp_export_procedure_set_capabilities (GIMP_EXPORT_PROCEDURE (procedure),
                                              GIMP_EXPORT_CAN_HANDLE_RGB  |
                                              GIMP_EXPORT_CAN_HANDLE_GRAY |
                                              GIMP_EXPORT_CAN_HANDLE_INDEXED,
                                              NULL, NULL, NULL);
    }

  return procedure;
}

static GimpValueArray *
pix_load (GimpProcedure         *procedure,
          GimpRunMode            run_mode,
          GFile                 *file,
          GimpMetadata          *metadata,
          GimpMetadataLoadFlags *flags,
          GimpProcedureConfig   *config,
          gpointer               run_data)
{
  GimpValueArray *return_vals;
  GimpImage      *image;
  GError         *error = NULL;

  gegl_init (NULL, NULL);

  image = load_image (file, &error);

  if (! image)
    return gimp_procedure_new_return_values (procedure,
                                             GIMP_PDB_EXECUTION_ERROR,
                                             error);

  return_vals = gimp_procedure_new_return_values (procedure,
                                                  GIMP_PDB_SUCCESS,
                                                  NULL);

  GIMP_VALUES_SET_IMAGE (return_vals, 1, image);

  return return_vals;
}

static GimpValueArray *
pix_export (GimpProcedure        *procedure,
            GimpRunMode           run_mode,
            GimpImage            *image,
            GFile                *file,
            GimpExportOptions    *options,
            GimpMetadata         *metadata,
            GimpProcedureConfig  *config,
            gpointer              run_data)
{
  GimpPDBStatusType  status = GIMP_PDB_SUCCESS;
  GimpExportReturn   export = GIMP_EXPORT_IGNORE;
  GList             *drawables;
  GError            *error  = NULL;

  gegl_init (NULL, NULL);

  export    = gimp_export_options_get_image (options, &image);
  drawables = gimp_image_list_layers (image);

  if (! export_image (file, image, drawables->data, &error))
    {
      status = GIMP_PDB_EXECUTION_ERROR;
    }

  if (export == GIMP_EXPORT_EXPORT)
    gimp_image_delete (image);

  g_list_free (drawables);
  return gimp_procedure_new_return_values (procedure, status, error);
}

/*
 * Description:
 *     Reads a 16-bit integer from a file in such a way that the machine's
 *     byte order should not matter.
 */

static gboolean
get_short (GInputStream  *input,
           guint16       *value,
           GError       **error)
{
  guchar buf[2];
  gsize  bytes_read;

  if (! g_input_stream_read_all (input, buf, 2,
                                 &bytes_read, NULL, error) ||
      bytes_read != 2)
    {
      return FALSE;
    }

  if (value)
    *value = (buf[0] << 8) + buf[1];

  return TRUE;
}

/*
 * Description:
 *     Writes a 16-bit integer to a file in such a way that the machine's
 *     byte order should not matter.
 */

static gboolean
put_short (GOutputStream  *output,
           guint16         value,
           GError        **error)
{
  guchar buf[2];

  buf[0] = (value >> 8) & 0xFF;
  buf[1] = value & 0xFF;

  return g_output_stream_write_all (output, buf, 2, NULL, NULL, error);
}

/*
 *  Description:
 *      load the given image into gimp
 *
 *  Arguments:
 *      filename      - name on the file to read
 *
 *  Return Value:
 *      Image id for the loaded image
 *
 */

static GimpImage *
load_image (GFile   *file,
            GError **error)
{
  GInputStream      *input;
  GeglBuffer        *buffer;
  GimpImageBaseType  imgtype;
  GimpImageType      gdtype;
  guchar            *dest;
  guchar            *dest_base;
  GimpImage         *image = NULL;
  GimpLayer         *layer;
  gushort            width, height, depth;
  gint               i, j, tile_height, row;

  PIX_DEBUG_PRINT ("Opening file: %s\n", gimp_file_get_utf8_name (file));

  gimp_progress_init_printf (_("Opening '%s'"),
                             g_file_get_parse_name (file));

  input = G_INPUT_STREAM (g_file_read (file, NULL, error));
  if (! input)
    return NULL;

  /* Read header information */
  if (! get_short (input, &width,  error) ||
      ! get_short (input, &height, error) ||
      ! get_short (input, NULL,    error) || /* Discard obsolete field */
      ! get_short (input, NULL,    error) || /* Discard obsolete field */
      ! get_short (input, &depth,  error))
    {
      g_object_unref (input);
      return NULL;
    }

  PIX_DEBUG_PRINT ("Width %hu\n",  width);
  PIX_DEBUG_PRINT ("Height %hu\n", height);

  if (depth == 8)
    {
      /* Loading a matte file */
      imgtype = GIMP_GRAY;
      gdtype  = GIMP_GRAY_IMAGE;
    }
  else if (depth == 24)
    {
      /* Loading an RGB file */
      imgtype = GIMP_RGB;
      gdtype  = GIMP_RGB_IMAGE;
    }
  else
    {
      /* Check if this is Esm Software PIX file format */
      gchar esm_header[22];
      gsize bytes_read;

      g_seekable_seek (G_SEEKABLE (input), 0, G_SEEK_SET, NULL, NULL);
      if (g_input_stream_read_all (input, &esm_header, sizeof (esm_header),
                                   &bytes_read, NULL, NULL))
        {
          esm_header[21] = '\0';

          if (g_str_has_prefix (esm_header, "Esm Software PIX file"))
            image = load_esm_image (input, error);

          if (image)
            {
              g_object_unref (input);
              gimp_progress_update (1.0);

              return image;
            }
        }

      /* Header is invalid */
      g_object_unref (input);
      return NULL;
    }

  image = gimp_image_new (width, height, imgtype);
  layer = gimp_layer_new (image, _("Background"),
                          width, height,
                          gdtype,
                          100,
                          gimp_image_get_default_new_layer_mode (image));
  gimp_image_insert_layer (image, layer, NULL, 0);

  buffer = gimp_drawable_get_buffer (GIMP_DRAWABLE (layer));

  tile_height = gimp_tile_height ();

  if (depth == 24)
    {
      /* Read a 24-bit Pix image */

      dest_base = dest = g_new (guchar, 3 * width * tile_height);

      for (i = 0; i < height;)
        {
          for (dest = dest_base, row = 0;
               row < tile_height && i < height;
               i++, row++)
            {
              guchar record[4];
              gsize  bytes_read;
              guchar count;

              /* Read a row of the image */
              j = 0;
              while (j < width)
                {
                  if (! g_input_stream_read_all (input, record, 4,
                                                 &bytes_read, NULL, error) ||
                      bytes_read != 4)
                    break;

                  for (count = 0; count < record[0]; ++count)
                    {
                      dest[0]   = record[3];
                      dest[1]   = record[2];
                      dest[2]   = record[1];
                      dest += 3;
                      j++;
                      if (j >= width)
                        break;
                    }
                }
            }

          gegl_buffer_set (buffer, GEGL_RECTANGLE (0, i - row, width, row), 0,
                           NULL, dest_base, GEGL_AUTO_ROWSTRIDE);

          gimp_progress_update ((double) i / (double) height);
        }

      g_free (dest_base);
    }
  else
    {
      /* Read an 8-bit Matte image */

      dest_base = dest = g_new (guchar, width * tile_height);

      for (i = 0; i < height;)
        {
          for (dest = dest_base, row = 0;
               row < tile_height && i < height;
               i++, row++)
            {
              guchar record[2];
              gsize  bytes_read;
              guchar count;

              /* Read a row of the image */
              j = 0;
              while (j < width)
                {
                  if (! g_input_stream_read_all (input, record, 2,
                                                 &bytes_read, NULL, error) ||
                      bytes_read != 2)
                    break;

                  for (count = 0; count < record[0]; ++count)
                    {
                      dest[j]   = record[1];
                      j++;
                      if (j >= width)
                        break;
                    }
                }

              dest += width;
            }

          gegl_buffer_set (buffer, GEGL_RECTANGLE (0, i - row, width, row), 0,
                           NULL, dest_base, GEGL_AUTO_ROWSTRIDE);

          gimp_progress_update ((double) i / (double) height);
        }

      g_free (dest_base);
    }

  g_object_unref (buffer);
  g_object_unref (input);

  gimp_progress_update (1.0);

  return image;
}

static GimpImage *
load_esm_image (GInputStream  *input,
                GError       **error)
{
  GimpImage      *image       = NULL;
  GFile          *temp_file   = NULL;
  FILE           *fp;
  goffset         file_size;

  g_seekable_seek (G_SEEKABLE (input), 0, G_SEEK_END, NULL, error);
  file_size = g_seekable_tell (G_SEEKABLE (input));
  g_seekable_seek (G_SEEKABLE (input), 21, G_SEEK_SET, NULL, error);

  /* Esm Software PIX format is just a JPEG with an extra 21 byte header */
  temp_file = gimp_temp_file ("jpeg");
  fp = g_fopen (g_file_peek_path (temp_file), "wb");

  if (! fp)
    {
      g_file_delete (temp_file, NULL, NULL);
      g_object_unref (temp_file);

      g_message (_("Error trying to open temporary JPEG file '%s' "
                   "for Esm Software pix loading: %s"),
                 gimp_file_get_utf8_name (temp_file),
                 g_strerror (errno));
      return NULL;
    }
  else
    {
      GimpProcedure  *procedure;
      GimpValueArray *return_vals;
      guchar          buffer[file_size - 21];

      if (! g_input_stream_read_all (input, buffer, sizeof (buffer),
                                     NULL, NULL, error))
        {
          g_file_delete (temp_file, NULL, NULL);
          g_object_unref (temp_file);

          g_printerr (_("Invalid Esm Software PIX file"));
          return NULL;
        }

      fwrite (buffer, sizeof (guchar), file_size, fp);
      fclose (fp);

      procedure   = gimp_pdb_lookup_procedure (gimp_get_pdb (), "file-jpeg-load");
      return_vals = gimp_procedure_run (procedure,
                                        "run-mode", GIMP_RUN_NONINTERACTIVE,
                                        "file",     temp_file,
                                        NULL);

      if (return_vals)
        {
          image = g_value_get_object (gimp_value_array_index (return_vals, 1));

          gimp_value_array_unref (return_vals);
        }

      g_file_delete (temp_file, NULL, NULL);
      g_object_unref (temp_file);
    }

  return image;
}

/*
 *  Description:
 *      export the given file out as an alias pix or matte file
 *
 *  Arguments:
 *      filename    - name of file to export to
 *      image       - image to export
 *      drawable    - current drawable
 */

static gboolean
export_image (GFile         *file,
              GimpImage     *image,
             GimpDrawable  *drawable,
              GError       **error)
{
  GOutputStream *output;
  GeglBuffer    *buffer;
  const Babl    *format;
  GCancellable  *cancellable;
  gint           width;
  gint           height;
  gint           depth, i, j, row, tile_height, rectHeight;
  gboolean       savingColor = TRUE;
  guchar        *src;
  guchar        *src_base;

  gimp_progress_init_printf (_("Exporting '%s'"),
                             g_file_get_parse_name (file));

  output = G_OUTPUT_STREAM (g_file_replace (file,
                                            NULL, FALSE, G_FILE_CREATE_NONE,
                                            NULL, error));
  if (! output)
    return FALSE;

  /* Get info about image */
  buffer = gimp_drawable_get_buffer (drawable);

  width  = gegl_buffer_get_width  (buffer);
  height = gegl_buffer_get_height (buffer);

  savingColor = ! gimp_drawable_is_gray (drawable);

  if (savingColor)
    format = babl_format ("R'G'B' u8");
  else
    format = babl_format ("Y' u8");

  depth = babl_format_get_bytes_per_pixel (format);

  /* Write the image header */
  PIX_DEBUG_PRINT ("Width %hu\n",  width);
  PIX_DEBUG_PRINT ("Height %hu\n", height);

  if (! put_short (output, width,  error) ||
      ! put_short (output, height, error) ||
      ! put_short (output, 0,      error) ||
      ! put_short (output, 0,      error))
    {
      cancellable = g_cancellable_new ();
      g_cancellable_cancel (cancellable);
      g_output_stream_close (output, cancellable, NULL);
      g_object_unref (cancellable);

      g_object_unref (output);
      g_object_unref (buffer);
      return FALSE;
    }

  tile_height = gimp_tile_height ();
  src_base    = g_new (guchar, tile_height * width * depth);

  if (savingColor)
    {
      /* Writing a 24-bit Pix image */

      if (! put_short (output, 24, error))
        goto fail;

      for (i = 0; i < height;)
        {
          rectHeight = (tile_height < (height - i)) ?
                        tile_height : (height - i);

          gegl_buffer_get (buffer, GEGL_RECTANGLE (0, i, width, rectHeight), 1.0,
                           format, src_base,
                           GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);

          for (src = src_base, row = 0;
               row < tile_height && i < height;
               i += 1, row += 1)
            {
              /* Write a row of the image */

              guchar record[4];

              record[0] = 1;
              record[3] = src[0];
              record[2] = src[1];
              record[1] = src[2];
              src += depth;
              for (j = 1; j < width; ++j)
                {
                  if ((record[3] != src[0]) ||
                      (record[2] != src[1]) ||
                      (record[1] != src[2]) ||
                      (record[0] == 255))
                    {
                      /* Write current RLE record and start a new one */

                      if (! g_output_stream_write_all (output, record, 4,
                                                       NULL, NULL, error))
                        {
                          goto fail;
                        }

                      record[0] = 1;
                      record[3] = src[0];
                      record[2] = src[1];
                      record[1] = src[2];
                    }
                  else
                    {
                      /* increment run length in current record */
                      record[0]++;
                    }
                  src += depth;
                }

              /* Write last record in row */

              if (! g_output_stream_write_all (output, record, 4,
                                               NULL, NULL, error))
                {
                  goto fail;
                }
            }

          gimp_progress_update ((double) i / (double) height);
        }
    }
  else
    {
      /* Writing a 8-bit Matte (Mask) image */

      if (! put_short (output, 8, error))
        goto fail;

      for (i = 0; i < height;)
        {
          rectHeight = (tile_height < (height - i)) ?
                        tile_height : (height - i);

          gegl_buffer_get (buffer, GEGL_RECTANGLE (0, i, width, rectHeight), 1.0,
                           format, src_base,
                           GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);

          for (src = src_base, row = 0;
               row < tile_height && i < height;
               i += 1, row += 1)
            {
              /* Write a row of the image */

              guchar record[2];

              record[0] = 1;
              record[1] = src[0];
              src += depth;
              for (j = 1; j < width; ++j)
                {
                  if ((record[1] != src[0]) || (record[0] == 255))
                    {
                      /* Write current RLE record and start a new one */

                      if (! g_output_stream_write_all (output, record, 2,
                                                       NULL, NULL, error))
                        {
                          goto fail;
                        }

                      record[0] = 1;
                      record[1] = src[0];
                    }
                  else
                    {
                      /* increment run length in current record */
                      record[0] ++;
                    }
                  src += depth;
                }

              /* Write last record in row */

              if (! g_output_stream_write_all (output, record, 2,
                                               NULL, NULL, error))
                {
                  goto fail;
                }
            }

          gimp_progress_update ((double) i / (double) height);
        }
    }

  g_free (src_base);
  g_object_unref (output);
  g_object_unref (buffer);

  gimp_progress_update (1.0);

  return TRUE;

 fail:

  cancellable = g_cancellable_new ();
  g_cancellable_cancel (cancellable);
  g_output_stream_close (output, cancellable, NULL);
  g_object_unref (cancellable);

  g_free (src_base);
  g_object_unref (output);
  g_object_unref (buffer);

  return FALSE;
}