/* webcollage-helper --- scales and pastes one image into another
 * xscreensaver, Copyright (c) 2002-2017 Jamie Zawinski <jwz@jwz.org>
 *
 * Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation.  No representations are made about the suitability of this
 * software for any purpose.  It is provided "as is" without express or 
 * implied warranty.
 */

/* This is the GDK + JPEGlib implementation.  See webcollage-helper-cocoa.m
   for the Cocoa implementation.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#if defined(HAVE_GDK_PIXBUF) && defined(HAVE_JPEGLIB)  /* whole file */

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>

#undef HAVE_STDLIB_H /* stupid jconfig.h! */
#include <jpeglib.h>
#include <gdk-pixbuf/gdk-pixbuf.h>


char *progname;
static int verbose_p = 0;

static void add_jpeg_comment (struct jpeg_compress_struct *cinfo);
static void write_pixbuf (GdkPixbuf *pb, const char *file);

static GdkPixbuf *
load_pixbuf (const char *file)
{
  GdkPixbuf *pb;
#ifdef HAVE_GTK2
  GError *err = NULL;

  pb = gdk_pixbuf_new_from_file (file, &err);
#else  /* !HAVE_GTK2 */
  pb = gdk_pixbuf_new_from_file (file);
#endif /* HAVE_GTK2 */

  if (!pb)
    {
#ifdef HAVE_GTK2
      fprintf (stderr, "%s: %s\n", progname, err->message);
      g_error_free (err);
#else  /* !HAVE_GTK2 */
      fprintf (stderr, "%s: unable to load %s\n", progname, file);
#endif /* !HAVE_GTK2 */
      exit (1);
    }

  return pb;
}


static void
bevel_image (GdkPixbuf **pbP, int bevel_pct,
             int x, int y, int w, int h)
{
  GdkPixbuf *pb = *pbP;
  int small_size = (w > h ? h : w);

  int bevel_size = small_size * (bevel_pct / 100.0);

  /* Use a proportionally larger bevel size for especially small images. */
  if      (bevel_size < 20 && small_size > 40) bevel_size = 20;
  else if (bevel_size < 10 && small_size > 20) bevel_size = 10;
  else if (bevel_size < 5)    /* too small to bother bevelling */
    return;

  /* Ensure the pixbuf has an alpha channel. */
  if (! gdk_pixbuf_get_has_alpha (pb))
    {
      GdkPixbuf *pb2 = gdk_pixbuf_add_alpha (pb, FALSE, 0, 0, 0);
      g_object_unref (pb);
      pb = pb2;
    }

  {
    guchar *data = gdk_pixbuf_get_pixels (pb);
    guchar *line;
    int rs = gdk_pixbuf_get_rowstride (pb);
    int ch = gdk_pixbuf_get_n_channels (pb);
    int xx, yy;
    double *ramp = (double *) malloc (sizeof(*ramp) * (bevel_size + 1));

    if (!ramp)
      {
        fprintf (stderr, "%s: out of memory (%d)\n", progname, bevel_size);
        exit (1);
      }

    for (xx = 0; xx <= bevel_size; xx++)
      {

# if 0  /* linear */
        ramp[xx] = xx / (double) bevel_size;

# else /* sinusoidal */
        double p = (xx / (double) bevel_size);
        double s = sin (p * M_PI / 2);
        ramp[xx] = s;
# endif
      }

    line = data + (rs * y);
    for (yy = 0; yy < h; yy++)
      {
        guchar *p = line + (x * ch);
        for (xx = 0; xx < w; xx++)
          {
            double rx, ry, r;

            if (xx < bevel_size)           rx = ramp[xx];
            else if (xx >= w - bevel_size) rx = ramp[w - xx - 1];
            else rx = 1;

            if (yy < bevel_size)           ry = ramp[yy];
            else if (yy >= h - bevel_size) ry = ramp[h - yy - 1];
            else ry = 1;

            r = rx * ry;
            if (r != 1)
              p[ch-1] *= r;

            p += ch;
          }
        line += rs;
      }

#if 0  /* show the ramp */
    line = data + (rs * y);
    for (yy = 0; yy < h; yy++)
      {
        guchar *p = line + (x * ch);
        for (xx = 0; xx < w; xx++)
          {
            int cc = 0;
            for (cc = 0; cc < ch-1; cc++)
              p[cc] = 255;
            p += ch;
          }
        line += rs;
      }
#endif

    free (ramp);

    if (verbose_p)
      fprintf (stderr, "%s: added %d%% bevel (%d px)\n", progname,
               bevel_pct, bevel_size);
  }

  *pbP = pb;
}


static void
paste (const char *paste_file,
       const char *base_file,
       double from_scale,
       double opacity, int bevel_pct,
       int from_x, int from_y, int to_x, int to_y,
       int w, int h)
{
  GdkPixbuf *paste_pb;
  GdkPixbuf *base_pb;

  int paste_w, paste_h;
  int base_w, base_h;

  paste_pb = load_pixbuf (paste_file);
  base_pb  = load_pixbuf (base_file);

  paste_w = gdk_pixbuf_get_width (paste_pb);
  paste_h = gdk_pixbuf_get_height (paste_pb);

  base_w = gdk_pixbuf_get_width (base_pb);
  base_h = gdk_pixbuf_get_height (base_pb);

  if (verbose_p)
    {
      fprintf (stderr, "%s: loaded %s: %dx%d\n",
               progname, base_file, base_w, base_h);
      fprintf (stderr, "%s: loaded %s: %dx%d\n",
               progname, paste_file, paste_w, paste_h);
    }

  if (from_scale != 1.0)
    {
      int new_w = paste_w * from_scale;
      int new_h = paste_h * from_scale;
      GdkPixbuf *new_pb = gdk_pixbuf_scale_simple (paste_pb, new_w, new_h,
                                                   GDK_INTERP_HYPER);
      g_object_unref (paste_pb);
      paste_pb = new_pb;
      paste_w = gdk_pixbuf_get_width (paste_pb);
      paste_h = gdk_pixbuf_get_height (paste_pb);

      if (verbose_p)
        fprintf (stderr, "%s: %s: scaled to %dx%d (%.2f)\n",
                 progname, paste_file, paste_w, paste_h, from_scale);
    }

  if (w == 0) w = paste_w - from_x;
  if (h == 0) h = paste_h - from_y;

  {
    int ofx = from_x;
    int ofy = from_y;
    int otx = to_x;
    int oty = to_y;
    int ow = w;
    int oh = h;

    int clipped = 0;

    if (from_x < 0)		/* from left out of bounds */
      {
        w += from_x;
        from_x = 0;
        clipped = 1;
      }

    if (from_y < 0)		/* from top out of bounds */
      {
        h += from_y;
        from_y = 0;
        clipped = 1;
      }

    if (to_x < 0)		/* to left out of bounds */
      {
        w += to_x;
        from_x -= to_x;
        to_x = 0;
        clipped = 1;
      }

    if (to_y < 0)		/* to top out of bounds */
      {
        h += to_y;
        from_y -= to_y;
        to_y = 0;
        clipped = 1;
      }

    if (from_x + w > paste_w)	/* from right out of bounds */
      {
        w = paste_w - from_x;
        clipped = 1;
      }

    if (from_y + h > paste_h)	/* from bottom out of bounds */
      {
        h = paste_h - from_y;
        clipped = 1;
      }

    if (to_x + w > base_w)	/* to right out of bounds */
      {
        w = base_w - to_x;
        clipped = 1;
      }

    if (to_y + h > base_h)	/* to bottom out of bounds */
      {
        h = base_h - to_y;
        clipped = 1;
      }


    if (clipped && verbose_p)
      {
        fprintf (stderr, "clipped from: %dx%d %d,%d %d,%d\n",
                 ow, oh, ofx, ofy, otx, oty);
        fprintf (stderr, "clipped   to: %dx%d %d,%d %d,%d\n",
                 w, h, from_x, from_y, to_x, to_y);
      }
  }

  if (bevel_pct > 0)
    bevel_image (&paste_pb, bevel_pct,
                 from_x, from_y, w, h);

  if (opacity == 1.0 && bevel_pct == 0)
    gdk_pixbuf_copy_area (paste_pb,
                          from_x, from_y, w, h,
                          base_pb,
                          to_x, to_y);
  else
    {
      from_x++;  /* gdk_pixbuf_composite gets confused about the bevel: */
      from_y++;  /* it leaves a stripe on the top and left if we try to */
      to_x++;    /* start at 0,0, so pull it right and down by 1 pixel. */
      to_y++;    /* (problem seen in gtk2-2.4.14-2.fc3) */
      w--;
      h--;

      if (w > 0 && h > 0)
        gdk_pixbuf_composite (paste_pb, base_pb,
                              to_x, to_y, w, h,
                              to_x - from_x, to_y - from_y,
                              1.0, 1.0,
                              GDK_INTERP_HYPER,
                              opacity * 255);
    }

  if (verbose_p)
    fprintf (stderr, "%s: pasted %dx%d from %d,%d to %d,%d\n",
             progname, paste_w, paste_h, from_x, from_y, to_x, to_y);

  g_object_unref (paste_pb);
  write_pixbuf (base_pb, base_file);
  g_object_unref (base_pb);
}


static guint32
parse_color (const char *s)
{
  static const char hex[128] =
    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0,
     0, 10,11,12,13,14,15,0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 10,11,12,13,14,15,0, 0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};

  unsigned char r=0, g=0, b=0;

  if      (!strcasecmp (s, "black")) ;
  else if (!strcasecmp (s, "white")) r = g = b = 0xFF;
  else if (!strcasecmp (s, "red"))   r = 0xFF;
  else if (!strcasecmp (s, "green")) g = 0xFF;
  else if (!strcasecmp (s, "blue"))  b = 0xFF;
  else
    {
      if (*s != '#' || strlen(s) != 7)
        {
          fprintf (stderr, "%s: unparsable color: \"%s\"\n", progname, s);
          exit (1);
        }
      s++;
      r = (hex[(int) s[0]] << 4) | hex[(int) s[1]], s += 2;
      g = (hex[(int) s[0]] << 4) | hex[(int) s[1]], s += 2;
      b = (hex[(int) s[0]] << 4) | hex[(int) s[1]], s += 2;
    }

  return (r << 16) | (g << 8) | b;
}


static void
create (const char *color,
        int w, int h,
        const char *file)
{
  int i;
  GdkPixbuf *pb;
  guint32 pixel = parse_color (color);
  unsigned char *bytes = malloc (w * h * 3);
  if (!bytes) abort();
  for (i = 0; i < w * h * 3; i += 3)
    {
      bytes[i]   = 0xFF & (pixel >> 16);
      bytes[i+1] = 0xFF & (pixel >> 8);
      bytes[i+2] = 0xFF & (pixel);
    }

  pb = gdk_pixbuf_new_from_data (bytes, GDK_COLORSPACE_RGB,
                                 FALSE, 8, /* alpha, sample size */
                                 w, h,
                                 w * 3,   /* rowstride */
                                 NULL, 0);
  if (!pb) abort();
  write_pixbuf (pb, file);
  g_object_unref (pb);
  free (bytes);
}


static void
write_pixbuf (GdkPixbuf *pb, const char *file)
{
  int jpeg_quality = 85;

  int w = gdk_pixbuf_get_width (pb);
  int h = gdk_pixbuf_get_height (pb);
  guchar *data = gdk_pixbuf_get_pixels (pb);
  int ww = gdk_pixbuf_get_rowstride (pb);
  int channels = gdk_pixbuf_get_n_channels (pb);

  struct jpeg_compress_struct cinfo;
  struct jpeg_error_mgr jerr;
  FILE *out;

  if (channels != 3)
    {
      fprintf (stderr, "%s: %d channels?\n", progname, channels);
      exit (1);
    }

  cinfo.err = jpeg_std_error (&jerr);
  jpeg_create_compress (&cinfo);

  out = fopen (file, "wb");
  if (!out)
    {
      char buf[255];
      sprintf (buf, "%.100s: %.100s", progname, file);
      perror (buf);
      exit (1);
    }
  else if (verbose_p)
    fprintf (stderr, "%s: writing %s...", progname, file);

  jpeg_stdio_dest (&cinfo, out);

  cinfo.image_width = w;
  cinfo.image_height = h;
  cinfo.input_components = channels;
  cinfo.in_color_space = JCS_RGB;

  jpeg_set_defaults (&cinfo);
  jpeg_simple_progression (&cinfo);
  jpeg_set_quality (&cinfo, jpeg_quality, TRUE);

  jpeg_start_compress (&cinfo, TRUE);
  add_jpeg_comment (&cinfo);

  {
    guchar *d = data;
    guchar *end = d + (ww * h);
    while (d < end)
      {
        jpeg_write_scanlines (&cinfo, &d, 1);
        d += ww;
      }
  }

  jpeg_finish_compress (&cinfo);
  jpeg_destroy_compress (&cinfo);

  if (verbose_p)
    {
      struct stat st;
      fflush (out);
      if (fstat (fileno (out), &st))
        {
          char buf[255];
          sprintf (buf, "%.100s: %.100s", progname, file);
          perror (buf);
          exit (1);
        }
      fprintf (stderr, " %luK\n", ((unsigned long) st.st_size + 1023) / 1024);
    }

  fclose (out);
}


static void
add_jpeg_comment (struct jpeg_compress_struct *cinfo)
{
  time_t now = time ((time_t *) 0);
  struct tm *tm = localtime (&now);
  const char fmt[] =
    "\r\n"
    "    Generated by WebCollage: Exterminate All Rational Thought. \r\n"
    "    Copyright (c) 1999-%Y by Jamie Zawinski <jwz@jwz.org> \r\n"
    "\r\n"
    "        https://www.jwz.org/webcollage/ \r\n"
    "\r\n"
    "    This is what the web looked like on %d %b %Y at %I:%M:%S %p %Z. \r\n"
    "\r\n";
  char comment[sizeof(fmt) + 100];
  strftime (comment, sizeof(comment)-1, fmt, tm);
  jpeg_write_marker (cinfo, JPEG_COM,
                     (unsigned char *) comment,
                     strlen (comment));
}


static void
usage (void)
{
  fprintf (stderr,
           "\nusage: %s [-v] paste-file base-file\n"
           "\t from-scale opacity\n"
           "\t from-x from-y to-x to-y w h\n"
           "\n"
           "\t Pastes paste-file into base-file.\n"
           "\t base-file will be overwritten (with JPEG data.)\n"
           "\t scaling is applied first: coordinates apply to scaled image.\n"
           "\n"
           "usage: %s [-v] color width height output-file\n"
           "\t Creates a new image of a solid color.\n\n",
           progname, progname);
  exit (1);
}


int
main (int argc, char **argv)
{
  int i;
  char *paste_file, *base_file, *s, dummy;
  double from_scale, opacity;
  int from_x, from_y, to_x, to_y, w, h, bevel_pct;

  i = 0;
  progname = argv[i++];
  s = strrchr (progname, '/');
  if (s) progname = s+1;

  if (!strcmp(argv[i], "-v"))
    verbose_p++, i++;

  if (argc == 11 || argc == 12)
    {
      paste_file = argv[i++];
      base_file = argv[i++];

      if (*paste_file == '-') usage();
      if (*base_file == '-') usage();

      s = argv[i++];
      if (1 != sscanf (s, " %lf %c", &from_scale, &dummy)) usage();
      if (from_scale <= 0 || from_scale > 100) usage();

      s = argv[i++];
      if (1 != sscanf (s, " %lf %c", &opacity, &dummy)) usage();
      if (opacity <= 0 || opacity > 1) usage();

      s = argv[i++]; if (1 != sscanf (s, " %d %c", &from_x, &dummy)) usage();
      s = argv[i++]; if (1 != sscanf (s, " %d %c", &from_y, &dummy)) usage();
      s = argv[i++]; if (1 != sscanf (s, " %d %c", &to_x, &dummy)) usage();
      s = argv[i++]; if (1 != sscanf (s, " %d %c", &to_y, &dummy)) usage();
      s = argv[i++]; if (1 != sscanf (s, " %d %c", &w, &dummy)) usage();
      s = argv[i];   if (1 != sscanf (s, " %d %c", &h, &dummy)) usage();

      bevel_pct = 10; /* #### */

      if (w < 0) usage();
      if (h < 0) usage();

# ifdef HAVE_GTK2
#  if !GLIB_CHECK_VERSION(2, 36 ,0)
      g_type_init ();
#  endif
# endif /* HAVE_GTK2 */

      paste (paste_file, base_file,
             from_scale, opacity, bevel_pct,
             from_x, from_y, to_x, to_y,
             w, h);
    }
  else if (argc == 4 || argc == 5)
    {
      char *color = argv[i++];
      s = argv[i++]; if (1 != sscanf (s, " %d %c", &w, &dummy)) usage();
      s = argv[i++]; if (1 != sscanf (s, " %d %c", &h, &dummy)) usage();
      paste_file = argv[i++];
      if (*paste_file == '-') usage();

      create (color, w, h, paste_file);
    }
  else
    {
      usage();
    }

  exit (0);
}

#endif /* HAVE_GDK_PIXBUF && HAVE_JPEGLIB -- whole file */