/*
 * gbr plug-in version 1.00
 * Loads/saves version 2 GIMP .gbr files, by Tim Newsome <drz@frody.bloke.com>
 * Some bits stolen from the .99.7 source tree.
 *
 * Added in GBR version 1 support after learning that there wasn't a
 * tool to read them.
 * July 6, 1998 by Seth Burgess <sjburges@gimp.org>
 *
 * Dec 17, 2000
 * Load and save GIMP brushes in GRAY or RGBA.  jtl + neo
 *
 *
 * TODO: Give some better error reporting on not opening files/bad headers
 *       etc.
 */

#include "config.h"

#include <glib.h>		/* Include early for G_OS_WIN32 */

#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#ifdef G_OS_WIN32
#include <io.h>
#endif

#ifndef _O_BINARY
#define _O_BINARY 0
#endif

#include <gtk/gtk.h>

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

#include "app/core/gimpbrush-header.h"
#include "app/core/gimppattern-header.h"

#include "libgimp/stdplugins-intl.h"


/* Declare local data types
 */

typedef struct
{
  gchar description[256];
  gint  spacing;
} t_info;

t_info info =
{   /* Initialize to this, change if non-interactive later */
  "GIMP Brush",
  10
};


/* Declare some local functions.
 */
static void   query          (void);
static void   run            (const gchar      *name,
			      gint              nparams,
			      const GimpParam  *param,
			      gint             *nreturn_vals,
			      GimpParam       **return_vals);

static gint32 load_image     (const gchar      *filename);
static gint   save_image     (const gchar      *filename,
			      gint32            image_ID,
			      gint32            drawable_ID);

static gint   save_dialog    (void);
static void   entry_callback (GtkWidget  *widget,
			      gpointer    data);


GimpPlugInInfo PLUG_IN_INFO =
{
  NULL,  /* init_proc  */
  NULL,  /* quit_proc  */
  query, /* query_proc */
  run,   /* run_proc   */
};


MAIN ()

static void
query (void)
{
  static GimpParamDef load_args[] =
  {
    { GIMP_PDB_INT32,  "run_mode",       "Interactive, non-interactive" },
    { GIMP_PDB_STRING, "filename",       "The name of the file to load" },
    { GIMP_PDB_STRING, "raw_filename",   "The name of the file to load" }
  };
  static GimpParamDef load_return_vals[] =
  {
    { GIMP_PDB_IMAGE,  "image",          "Output image" }
  };

  static GimpParamDef save_args[] =
  {
    { GIMP_PDB_INT32,    "run_mode",     "Interactive, non-interactive" },
    { GIMP_PDB_IMAGE,    "image",        "Input image" },
    { GIMP_PDB_DRAWABLE, "drawable",     "Drawable to save" },
    { GIMP_PDB_STRING,   "filename",     "The name of the file to save the image in" },
    { GIMP_PDB_STRING,   "raw_filename", "The name of the file to save the image in" },
    { GIMP_PDB_INT32,    "spacing",      "Spacing of the brush" },
    { GIMP_PDB_STRING,   "description",  "Short description of the brush" }
  };

  gimp_install_procedure ("file_gbr_load",
                          "Loads GIMP brushes (1 or 4 bpp and old .gpb format)",
                          "FIXME: write help",
                          "Tim Newsome, Jens Lautenbacher, Sven Neumann",
                          "Tim Newsome, Jens Lautenbacher, Sven Neumann",
                          "1997-2000",
                          "<Load>/GBR",
                          NULL,
                          GIMP_PLUGIN,
                          G_N_ELEMENTS (load_args),
                          G_N_ELEMENTS (load_return_vals),
                          load_args, load_return_vals);

  gimp_install_procedure ("file_gbr_save",
                          "saves files in the .gbr file format",
                          "Yeah!",
                          "Tim Newsome, Jens Lautenbacher, Sven Neumann",
                          "Tim Newsome, Jens Lautenbacher, Sven Neumann",
                          "1997-2000",
                          "<Save>/GBR",
                          "RGBA, GRAY",
                          GIMP_PLUGIN,
                          G_N_ELEMENTS (save_args), 0,
                          save_args, NULL);

  gimp_register_magic_load_handler ("file_gbr_load",
				    "gbr, gpb",
				    "",
				    "20, string, GIMP");
  gimp_register_save_handler       ("file_gbr_save",
				    "gbr",
				    "");
}

static void
run (const gchar      *name,
     gint              nparams,
     const GimpParam  *param,
     gint             *nreturn_vals,
     GimpParam       **return_vals)
{
  static GimpParam  values[2];
  GimpRunMode       run_mode;
  GimpPDBStatusType status = GIMP_PDB_SUCCESS;
  gint32            image_ID;
  gint32            drawable_ID;
  GimpExportReturn  export = GIMP_EXPORT_CANCEL;

  run_mode = param[0].data.d_int32;

  INIT_I18N ();

  *nreturn_vals = 1;
  *return_vals  = values;

  values[0].type          = GIMP_PDB_STATUS;
  values[0].data.d_status = GIMP_PDB_EXECUTION_ERROR;

  if (strcmp (name, "file_gbr_load") == 0)
    {
      image_ID = load_image (param[1].data.d_string);

      if (image_ID != -1)
	{
	  *nreturn_vals = 2;
	  values[1].type         = GIMP_PDB_IMAGE;
	  values[1].data.d_image = image_ID;
	}
      else
	{
	  status = GIMP_PDB_EXECUTION_ERROR;
	}
    }
  else if (strcmp (name, "file_gbr_save") == 0)
    {
      image_ID    = param[1].data.d_int32;
      drawable_ID = param[2].data.d_int32;

      /*  eventually export the image */
      switch (run_mode)
	{
	case GIMP_RUN_INTERACTIVE:
	case GIMP_RUN_WITH_LAST_VALS:
	  gimp_ui_init ("gbr", FALSE);
	  export = gimp_export_image (&image_ID, &drawable_ID, "GBR",
				      GIMP_EXPORT_CAN_HANDLE_GRAY  |
				      GIMP_EXPORT_CAN_HANDLE_RGB   |
				      GIMP_EXPORT_CAN_HANDLE_ALPHA);
	  if (export == GIMP_EXPORT_CANCEL)
	    {
	      values[0].data.d_status = GIMP_PDB_CANCEL;
	      return;
	    }
	  break;
	default:
	  break;
	}

      switch (run_mode)
	{
	case GIMP_RUN_INTERACTIVE:
	  /*  Possibly retrieve data  */
	  strncpy (info.description, gimp_drawable_name (drawable_ID), 256);
	  gimp_get_data ("file_gbr_save", &info);
	  if (! save_dialog ())
	    status = GIMP_PDB_CANCEL;
	  break;

	case GIMP_RUN_NONINTERACTIVE:
	  /* FIXME - need a real GIMP_RUN_NONINTERACTIVE */
	  if (nparams != 7)
	    {
	      status = GIMP_PDB_CALLING_ERROR;
	    }
	  else
	    {
	      info.spacing = (param[5].data.d_int32);
	      strncpy (info.description, param[6].data.d_string, 256);
	    }
	  break;

	case GIMP_RUN_WITH_LAST_VALS:
	  gimp_get_data ("file_gbr_save", &info);
	  break;
	}

      if (status == GIMP_PDB_SUCCESS)
	{
	  if (save_image (param[3].data.d_string, image_ID, drawable_ID))
	    {
	      gimp_set_data ("file_gbr_save", &info, sizeof(info));
	    }
	  else
	    {
	      status = GIMP_PDB_EXECUTION_ERROR;
	    }
	}

      if (export == GIMP_EXPORT_EXPORT)
	gimp_image_delete (image_ID);
    }
  else
    {
      status = GIMP_PDB_CALLING_ERROR;
    }

  values[0].data.d_status = status;
}

static gint32
load_image (const gchar *filename)
{
  gchar             *temp;
  gchar             *name = NULL;
  gint               fd;
  BrushHeader        bh;
  guchar            *brush_buf = NULL;
  gint32             image_ID;
  gint32             layer_ID;
  GimpDrawable      *drawable;
  GimpPixelRgn       pixel_rgn;
  gint               bn_size;
  GimpImageBaseType  base_type;
  GimpImageType      image_type;
  gssize             size;

  fd = open (filename, O_RDONLY | _O_BINARY);

  if (fd == -1)
    {
      g_message (_("Can't open '%s':\n%s"),
                 filename, g_strerror (errno));
      return -1;
    }

  temp = g_strdup_printf (_("Opening '%s'..."), filename);
  gimp_progress_init (temp);
  g_free (temp);

  if (read (fd, &bh, sizeof (bh)) != sizeof (bh))
    {
      close (fd);
      return -1;
    }

  /*  rearrange the bytes in each unsigned int  */
  bh.header_size  = g_ntohl (bh.header_size);
  bh.version      = g_ntohl (bh.version);
  bh.width        = g_ntohl (bh.width);
  bh.height       = g_ntohl (bh.height);
  bh.bytes        = g_ntohl (bh.bytes);
  bh.magic_number = g_ntohl (bh.magic_number);
  bh.spacing      = g_ntohl (bh.spacing);

  switch (bh.version)
    {
    case 1:
      /* Version 1 didn't have a magic number and had no spacing  */
      bh.spacing = 25;
      /* And we need to rewind the handle, 4 due spacing and 4 due magic */
      lseek (fd, -8, SEEK_CUR);
      bh.header_size += 8;
      break;

    case 3: /*  cinepaint brush  */
      if (bh.bytes == 18 /* FLOAT16_GRAY_GIMAGE */)
        {
          bh.bytes = 2;
        }
      else
        {
          g_message (_("Unsupported brush format"));
          close (fd);
          return -1;
        }
      /*  fallthrough  */

    case 2:
      if (bh.magic_number == GBRUSH_MAGIC && bh.header_size > sizeof (bh))
        break;

    default:
      g_message (_("Unsupported brush format"));
      close (fd);
      return -1;
    }

  if ((bn_size = (bh.header_size - sizeof (bh))) > 0)
    {
      name = g_new (gchar, bn_size);
      if ((read (fd, name, bn_size)) < bn_size)
	{
	  g_message (_("Error in GIMP brush file\n'%s'"), filename);
	  close (fd);
	  g_free (name);
	  return -1;
	}
    }
  else
    {
      name = g_strdup (_("Unnamed"));
    }

  /* Now there's just raw data left. */

  size = bh.width * bh.height * bh.bytes;
  brush_buf = g_malloc (size);

  if (read (fd, brush_buf, size) != size)
    {
      close (fd);
      g_free (brush_buf);
      g_free (name);
      return -1;
    }


  switch (bh.bytes)
    {
    case 1:
      {
        PatternHeader ph;

        /*  For backwards-compatibility, check if a pattern follows.
            The obsolete .gpb format did it this way.  */

        if (read (fd, &ph, sizeof(ph)) == sizeof(ph))
          {
            /*  rearrange the bytes in each unsigned int  */
            ph.header_size  = g_ntohl (ph.header_size);
            ph.version      = g_ntohl (ph.version);
            ph.width        = g_ntohl (ph.width);
            ph.height       = g_ntohl (ph.height);
            ph.bytes        = g_ntohl (ph.bytes);
            ph.magic_number = g_ntohl (ph.magic_number);

            if (ph.magic_number == GPATTERN_MAGIC &&
                ph.version == 1                   &&
                ph.header_size > sizeof (ph)      &&
                ph.bytes   == 3                   &&
                ph.width   == bh.width            &&
                ph.height  == bh.height           &&
                lseek (fd, ph.header_size - sizeof (ph), SEEK_CUR) > 0)
              {
                guchar *plain_brush = brush_buf;
                gint    i;

                bh.bytes = 4;
                brush_buf = g_malloc (4 * bh.width * bh.height);

                for (i = 0; i < ph.width * ph.height; i++)
                  {
                    if (read (fd, brush_buf + i * 4, 3) != 3)
                      {
                        close (fd);
                        g_free (name);
                        g_free (plain_brush);
                        g_free (brush_buf);
                        return -1;
                      }
                    brush_buf[i * 4 + 3] = plain_brush[i];
                  }
                g_free (plain_brush);
              }
          }
      }
      break;

    case 2:
      {
        guint16 *buf = (guint16 *) brush_buf;
        gint     i;

        for (i = 0; i < bh.width * bh.height; i++, buf++)
          {
            union
            {
              guint16 u[2];
              gfloat  f;
            } short_float;

#if G_BYTE_ORDER == G_LITTLE_ENDIAN
            short_float.u[0] = 0;
            short_float.u[1] = GUINT16_FROM_BE (*buf);
#else
            short_float.u[0] = GUINT16_FROM_BE (*buf);
            short_float.u[1] = 0;
#endif

            brush_buf[i] = (guchar) (short_float.f *= 255.9999);
          }

        bh.bytes = 1;
      }
      break;

    default:
      break;
    }

  /*
   * Create a new image of the proper size and
   * associate the filename with it.
   */

  switch (bh.bytes)
    {
    case 1:
      base_type = GIMP_GRAY;
      image_type = GIMP_GRAY_IMAGE;
      break;
    case 4:
      base_type = GIMP_RGB;
      image_type = GIMP_RGBA_IMAGE;
      break;
    default:
      g_message ("Unsupported brush depth: %d\n"
                 "GIMP Brushes must be GRAY or RGBA\n",
		 bh.bytes);
      return -1;
    }

  image_ID = gimp_image_new (bh.width, bh.height, base_type);
  gimp_image_set_filename (image_ID, filename);

  layer_ID = gimp_layer_new (image_ID, name,
			     bh.width, bh.height,
			     image_type, 100, GIMP_NORMAL_MODE);
  gimp_image_add_layer (image_ID, layer_ID, 0);

  g_free (name);

  drawable = gimp_drawable_get (layer_ID);
  gimp_pixel_rgn_init (&pixel_rgn, drawable,
		       0, 0, drawable->width, drawable->height,
		       TRUE, FALSE);

  gimp_pixel_rgn_set_rect (&pixel_rgn, brush_buf,
			   0, 0, bh.width, bh.height);
  g_free (brush_buf);

  if (image_type == GIMP_GRAY_IMAGE)
    gimp_invert (layer_ID);

  close (fd);

  gimp_drawable_flush (drawable);
  gimp_progress_update (1.0);

  return image_ID;
}

static gint
save_image (const gchar *filename,
	    gint32       image_ID,
	    gint32       drawable_ID)
{
  gint          fd;
  BrushHeader   bh;
  guchar       *buffer;
  GimpDrawable *drawable;
  gint          line;
  gint          x;
  GimpPixelRgn  pixel_rgn;
  gchar        *temp;

  if (gimp_drawable_type (drawable_ID) != GIMP_GRAY_IMAGE &&
      gimp_drawable_type (drawable_ID) != GIMP_RGBA_IMAGE)
    {
      g_message (_("GIMP brushes are either GRAYSCALE or RGBA\n"));
      return FALSE;
    }

  fd = open (filename, O_CREAT | O_TRUNC | O_WRONLY | _O_BINARY, 0644);

  if (fd == -1)
    {
      g_message (_("Can't open '%s' for writing:\n%s"),
                 filename, g_strerror (errno));
      return FALSE;
    }

  temp = g_strdup_printf (_("Saving %s:"), filename);
  gimp_progress_init (temp);
  g_free (temp);

  drawable = gimp_drawable_get (drawable_ID);
  gimp_pixel_rgn_init (&pixel_rgn, drawable,
		       0, 0, drawable->width, drawable->height,
		       FALSE, FALSE);

  bh.header_size  = g_htonl (sizeof (bh) + strlen (info.description) + 1);
  bh.version      = g_htonl (2);
  bh.width        = g_htonl (drawable->width);
  bh.height       = g_htonl (drawable->height);
  bh.bytes        = g_htonl (drawable->bpp);
  bh.magic_number = g_htonl (GBRUSH_MAGIC);
  bh.spacing      = g_htonl (info.spacing);

  if (write (fd, &bh, sizeof (bh)) != sizeof (bh))
    {
      close (fd);
      return FALSE;
    }

  if (write (fd, info.description, strlen(info.description) + 1) !=
      strlen (info.description) + 1)
    {
      close(fd);
      return FALSE;
    }

  buffer = g_malloc (drawable->width * drawable->bpp);
  for (line = 0; line < drawable->height; line++)
    {
      gimp_pixel_rgn_get_row (&pixel_rgn, buffer, 0, line, drawable->width);

      if (drawable->bpp == 1)
	{
	  for (x = 0; x < drawable->width; x++)
	    buffer[x] = 255 - buffer[x];
	}

      if (write (fd, buffer,
		 drawable->width * drawable->bpp) != drawable->width * drawable->bpp)
	{
	  g_free (buffer);
	  close (fd);
	  return FALSE;
	}
      gimp_progress_update ((gdouble) line / (gdouble) drawable->height);
    }

  g_free (buffer);
  close (fd);

  return TRUE;
}

static gint
save_dialog (void)
{
  GtkWidget *dlg;
  GtkWidget *table;
  GtkWidget *entry;
  GtkWidget *spinbutton;
  GtkObject *adj;
  gboolean   run;

  dlg = gimp_dialog_new (_("Save as Brush"), "gbr",
                         NULL, 0,
			 gimp_standard_help_func, "filters/gbr.html",

			 GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
			 GTK_STOCK_OK,     GTK_RESPONSE_OK,

			 NULL);

  /* The main table */
  table = gtk_table_new (2, 2, FALSE);
  gtk_container_set_border_width (GTK_CONTAINER (table), 6);
  gtk_table_set_row_spacings (GTK_TABLE (table), 2);
  gtk_table_set_col_spacings (GTK_TABLE (table), 4);
  gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dlg)->vbox), table, TRUE, TRUE, 0);
  gtk_widget_show (table);

  spinbutton = gimp_spin_button_new (&adj,
				     info.spacing, 1, 1000, 1, 10, 0, 1, 0);
  gimp_table_attach_aligned (GTK_TABLE (table), 0, 0,
			     _("Spacing:"), 1.0, 0.5,
			     spinbutton, 1, TRUE);

  g_signal_connect (adj, "value_changed",
                    G_CALLBACK (gimp_int_adjustment_update),
                    &info.spacing);

  entry = gtk_entry_new ();
  gtk_widget_set_size_request (entry, 200, -1);
  gtk_entry_set_text (GTK_ENTRY (entry), info.description);
  gimp_table_attach_aligned (GTK_TABLE (table), 0, 1,
			     _("Description:"), 1.0, 0.5,
			     entry, 1, FALSE);

  g_signal_connect (entry, "changed",
                    G_CALLBACK (entry_callback),
                    info.description);

  gtk_widget_show (dlg);

  run = (gtk_dialog_run (GTK_DIALOG (dlg)) == GTK_RESPONSE_OK);

  gtk_widget_destroy (dlg);

  return run;
}

static void
entry_callback (GtkWidget *widget,
		gpointer   data)
{
  strncpy (info.description, gtk_entry_get_text (GTK_ENTRY (widget)), 256);
}