#include <stdio.h>
#include <stdarg.h>
#include <strings.h>

#include "gif.h"

static GIFREADER *gr;
static const char *broken_ext_name;
static int appext_is_netscape;
static int scr_w;
static int scr_h;
static int scr_m;
static int scr_bpp;
static int scr_bg;
static unsigned char (*gcmap)[3];
static unsigned char (*lcmap)[3];
static unsigned char (*cmap)[3];
static int gx_disp;
static int gx_input;
static int gx_delay;
static int gx_transp;

static int gifdump_read_input(void *cookie __attribute__((__unused__)), void *buf, int len)
{
 int i;

 i = fread(buf,1,len,stdin);
 if (i < 0) return(-1);
 return(i);
}

static void gifdump_error(void *cookie __attribute__((__unused__)), int err, ...)
{
 va_list ap;

 va_start(ap,err);
 switch (err)
  { default:
       printf("Impossible error %d\n",err);
       abort();
       break;
    case GIFREAD_ERR_READERROR:
       printf("*** Read error reading %s\n",va_arg(ap,const char *));
       exit(1);
       break;
    case GIFREAD_ERR_UNXEOF:
       printf("*** Unexpected EOF reading %s\n",va_arg(ap,const char *));
       exit(1);
       break;
    case GIFREAD_ERR_BADSIG:
       printf("*** Invalid signature\n");
       exit(1);
       break;
    case GIFREAD_ERR_87a_RESERVED:
       if (va_arg(ap,int)) printf("*** Reserved bit set in word 5 of screen descriptor (ignoring)\n");
       if (va_arg(ap,int)) printf("*** Word 7 of screen descriptor is not zero (ignoring)\n");
       break;
    case GIFREAD_ERR_TEXTEXT_HDRSIZE:
       printf("*** plain text extension block length %d wrong\n",va_arg(ap,int));
       broken_ext_name = "plain text";
       break;
    case GIFREAD_ERR_GFXCTLEXT_HDRSIZE:
       printf("*** graphic control extension block length %d wrong\n",va_arg(ap,int));
       broken_ext_name = "graphic control";
       break;
    case GIFREAD_ERR_GFXCTLEXT_MBZ:
       printf("*** Reserved bits not zero in graphic control extension header (ignoring)\n");
       break;
    case GIFREAD_ERR_GFXCTLEXT_BADTERM:
       printf("*** graphic control extension block terminator wrong\n");
       broken_ext_name = "graphic control";
       break;
    case GIFREAD_ERR_GFXCTLEXT_BADDISP:
       printf("*** Reserved disposal value %d graphic control extension byte 0 (treating as 0)\n",va_arg(ap,int));
       break;
    case GIFREAD_ERR_APPEXT_HDRSIZE:
       printf("*** application extension block length %d wrong\n",va_arg(ap,int));
       broken_ext_name = "application";
       break;
    case GIFREAD_ERR_IMGDESC_RESERVED:
       printf("*** Reserved bits set in image descriptor (ignoring)\n");
       break;
    case GIFREAD_ERR_IMGDESC_CODESIZE:
       printf("***\tcodesize %d ",va_arg(ap,int));
       printf("not expected for bpp %d, using codesize\n",va_arg(ap,int));
       break;
    case GIFREAD_ERR_LZW_OVERFLOW:
       printf("***\t\tError, lzw table overflow (forcing clear)\n");
       break;
    case GIFREAD_ERR_LZW_BAD_KWKWK:
       printf("***\t\tError, KwKwK code with no previous code (ignoring)\n");
       break;
    case GIFREAD_ERR_LZW_BAD_CODE:
       printf("***\t\tError, LZW code %d out of range (ignoring)\n",va_arg(ap,int));
       break;
    case GIFREAD_ERR_SKIPJUNK:
       printf("*** Skipping junk in file...\n");
       break;
    case GIFREAD_ERR_TRAILJUNK:
       printf("*** Skipping trailing junk...\n");
       break;
  }
 va_end(ap);
}

static void clear_gx(void)
{
 gx_disp = GIFREAD_GX_DISP_NONE;
 gx_input = 0;
 gx_delay = 0;
 gx_transp = -1;
}

static void gifdump_detail(void *cookie __attribute__((__unused__)), unsigned int what, ...)
{
 va_list ap;

 va_start(ap,what);
 switch (what)
  { default:
       abort();
       break;
    case GIFREAD_DETAIL_DATAREAD:
	{ const unsigned char *data;
	  int len;
	  const char *what;
	  int i;
	  data = va_arg(ap,const unsigned char *);
	  len = va_arg(ap,int);
	  what = va_arg(ap,const char *);
	  printf("[read %s:",what);
	  for (i=0;i<len;i++) printf(" %02x",data[i]);
	  printf("]\n");
	}
       break;
    case GIFREAD_DETAIL_SIGNATURE:
	{ const unsigned char *sig;
	  int vers;
	  sig = va_arg(ap,const unsigned char *);
	  vers = va_arg(ap,int);
	  printf("Signature: %.6s\n",sig);
	  if (vers == GIFREAD_VERS_OTHER) printf("*** Unrecognized GIF version\n");
	}
       break;
    case GIFREAD_DETAIL_SCRDESC:
       printf("Screen descriptor:\n");
       scr_w = va_arg(ap,int);
       scr_h = va_arg(ap,int);
       printf("\tSize = %dx%d\n",scr_w,scr_h);
       scr_m = va_arg(ap,int);
       switch (scr_m)
	{ case GIFREAD_CMAP_NONE:
	     printf("\tNo global color map\n");
	     break;
	  case GIFREAD_CMAP_UNSORTED:
	     printf("\tHas global color map (not sorted)\n");
	     break;
	  case GIFREAD_CMAP_SORTED:
	     printf("\tHas global color map (sorted)\n");
	     break;
	  default:
	     abort();
	     break;
	}
       printf("\tColor resolution = %d\n",va_arg(ap,int));
       scr_bpp = va_arg(ap,int);
       printf("\tBits/pixel = %d\n",scr_bpp);
       scr_bg = va_arg(ap,int);
       printf("\tBackground = %d\n",scr_bg);
	{ int ar;
	  ar = va_arg(ap,int);
	  if (ar == 0)
	   { printf("\tAspect ratio not specified\n");
	   }
	  else
	   { int arn;
	     int ard;
	     arn = ar + 15;
	     ard = 64;
	     // Don't worry about divisors other than 2
	     //  since ard is a power of 2
	     while (((arn|ard) & 1) == 0)
	      { arn >>= 1;
		ard >>= 1;
	      }
	     printf("\tAspect ratio w:h = %d:%d\n",arn,ard);
	   }
	}
       clear_gx();
       break;
    case GIFREAD_DETAIL_UNKEXT:
       printf("Extension block:\n");
       printf("\tExtension code %02x\n",va_arg(ap,int));
       break;
    case GIFREAD_DETAIL_UNKEXT_DATA:
	{ const unsigned char *dp;
	  int len;
	  dp = va_arg(ap,const unsigned char *);
	  len = va_arg(ap,int);
	  printf("\tData %d:",len);
	  for (;len>0;len--) printf(" %02x",*dp++);
	  printf("\n");
	}
       break;
    case GIFREAD_DETAIL_BROKEN_EXT:
	{ const unsigned char *dp;
	  int len;
	  dp = va_arg(ap,const unsigned char *);
	  len = va_arg(ap,int);
	  printf("Broken %s extension data %d:",broken_ext_name,len);
	  for (;len>0;len--) printf(" %02x",*dp++);
	  printf("\n");
	}
       break;
    case GIFREAD_DETAIL_TEXTEXT:
	{ unsigned int gx;
	  unsigned int gy;
	  unsigned int gw;
	  unsigned int gh;
	  unsigned int ccw;
	  unsigned int cch;
	  unsigned int fg;
	  unsigned int bg;
	  gx = va_arg(ap,unsigned int);
	  gy = va_arg(ap,unsigned int);
	  gw = va_arg(ap,unsigned int);
	  gh = va_arg(ap,unsigned int);
	  ccw = va_arg(ap,unsigned int);
	  cch = va_arg(ap,unsigned int);
	  fg = va_arg(ap,unsigned int);
	  bg = va_arg(ap,unsigned int);
	  printf("\tPlain text extension:\n");
	  printf("\t\tGrid area: %ux%u+%u+%u\n",gw,gh,gx,gy);
	  printf("\t\tCharcell: %ux%u\n",ccw,cch);
	  if (gw % ccw) printf("*** Grid width is not a multiple of charcell width (ignoring)\n");
	  if (gh % cch) printf("*** Grid height is not a multiple of charcell height (ignoring)\n");
	  printf("\t\tPixel values: fg=%u bg=%u\n",fg,bg);
	}
       break;
    case GIFREAD_DETAIL_TEXTEXT_DATA:
	{ const unsigned char *dp;
	  int len;
	  dp = va_arg(ap,const unsigned char *);
	  len = va_arg(ap,int);
	  printf("Plain text extension data %d:",len);
	  for (;len>0;len--) printf(" %02x",*dp++);
	  printf("\n");
	}
       break;
    case GIFREAD_DETAIL_GFXCTLEXT:
       gx_disp = va_arg(ap,int);
       gx_input = va_arg(ap,int);
       gx_delay = va_arg(ap,int);
       gx_transp = va_arg(ap,int);
       printf("\tGraphic control extension:\n");
       switch (gx_disp)
	{ case GIFREAD_GX_DISP_NONE:
	     printf("\t\tDisposal: none\n");
	     break;
	  case GIFREAD_GX_DISP_LEAVE:
	     printf("\t\tDisposal: leave\n");
	     break;
	  case GIFREAD_GX_DISP_BG:
	     printf("\t\tDisposal: clear to background\n");
	     break;
	  case GIFREAD_GX_DISP_PREV:
	     printf("\t\tDisposal: restore previous\n");
	     break;
	  default:
	     abort();
	     break;
	}
       printf("\t\tUser input: %s\n",gx_input?"yes":"no");
       if (gx_delay) printf("\t\tDelay: %d ms\n",gx_delay*10); else printf("\t\tNo delay\n");
       if (gx_transp < 0) printf("\t\tNo transparent pixel\n"); else printf("\t\tTransparent pixel: %d\n",gx_transp);
       break;
    case GIFREAD_DETAIL_COMMEXT:
       printf("Comment extension begins\n");
       break;
    case GIFREAD_DETAIL_COMMEXT_DATA:
	{ const unsigned char *dp;
	  int len;
	  dp = va_arg(ap,const unsigned char *);
	  len = va_arg(ap,int);
	  printf("Comment extension data %d:",len);
	  for (;len>0;len--) printf(" %02x",*dp++);
	  printf("\n");
	}
       break;
    case GIFREAD_DETAIL_APPEXT:
	{ const unsigned char *dp;
	  dp = va_arg(ap,const unsigned char *);
	  printf("Application extension: %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n",dp[0],dp[1],dp[2],dp[3],dp[4],dp[5],dp[6],dp[7],dp[8],dp[9],dp[10]);
	  appext_is_netscape = !bcmp(dp,"NETSCAPE2.0",11);
	}
       break;
    case GIFREAD_DETAIL_APPEXT_DATA:
	{ const unsigned char *dp;
	  int len;
	  dp = va_arg(ap,const unsigned char *);
	  len = va_arg(ap,int);
	  if (appext_is_netscape && (len == 3) && (dp[0] == 1))
	   { printf("Netscape looping extension: loop count %d\n",(dp[2]<<8)|dp[1]);
	   }
	  else
	   { printf("Application extension data %d:",len);
	     for (;len>0;len--) printf(" %02x",*dp++);
	     printf("\n");
	   }
	}
       break;
    case GIFREAD_DETAIL_IMGDESC:
	{ int x;
	  int y;
	  int w;
	  int h;
	  int m;
	  int i;
	  int b;
	  x = va_arg(ap,int);
	  y = va_arg(ap,int);
	  w = va_arg(ap,int);
	  h = va_arg(ap,int);
	  m = va_arg(ap,int);
	  i = va_arg(ap,int);
	  b = va_arg(ap,int);
	  printf("Image descriptor:\n");
	  printf("\tGeometry = %dx%d+%d+%d\n",w,h,x,y);
	  if ((x+w > scr_w) || (y+h > scr_h))
	   { printf("***\tGeometry out of bounds (clipping)\n");
	   }
	  switch (m)
	   { case GIFREAD_CMAP_NONE:
		printf("\tNo local color map\n");
		break;
	     case GIFREAD_CMAP_UNSORTED:
		printf("\tHas local color map (not sorted)\n");
		break;
	     case GIFREAD_CMAP_SORTED:
		printf("\tHas local color map (sorted)\n");
		break;
	     default:
		abort();
		break;
	   }
	  printf("\t%s\n",i?"Interlaced":"Not interlaced");
	  if (m == GIFREAD_CMAP_NONE)
	   { printf("\tBits/pixel = %d (global value)\n",scr_bpp);
	   }
	  else
	   { printf("\tBits/pixel = %d\n",b);
	   }
	  lcmap = 0;
	  cmap = gcmap;
	}
       break;
    case GIFREAD_DETAIL_LZW_DATA:
	{ const unsigned char *dp;
	  int len;
	  dp = va_arg(ap,const unsigned char *);
	  len = va_arg(ap,int);
	  printf("LZW compressed data %d:",len);
	  for (;len>0;len--) printf(" %02x",*dp++);
	  printf("\n");
	  if (len == 0) clear_gx();
	}
       break;
    case GIFREAD_DETAIL_LZW_BYTES:
	{ int v;
	  v = va_arg(ap,int);
	  printf("LZW input byte %d%d%d%d %d%d%d%d\n",(v>>7)&1,(v>>6)&1,(v>>5)&1,(v>>4)&1,(v>>3)&1,(v>>2)&1,(v>>1)&1,v&1);
	}
       break;
    case GIFREAD_DETAIL_LZW_CODES:
	{ int v;
	  int b;
	  v = va_arg(ap,int);
	  b = va_arg(ap,int);
	  printf("LZW codeword ");
	  for (b--;b>=0;b--)
	   { printf("%d",(v>>b)&1);
	     if (b && !(b&3)) printf(" ");
	   }
	  printf("\n");
	}
       break;
    case GIFREAD_DETAIL_PIXELS:
	{ int v;
	  v = va_arg(ap,int);
	  if (v == gx_transp)
	   { printf("\t\tpixel %d [transparent]\n",v);
	   }
	  else if (cmap)
	   { printf("\t\tpixel %d [%d,%d,%d]\n",v,cmap[v][0],cmap[v][1],cmap[v][2]);
	   }
	  else
	   { printf("\t\tpixel %d\n",v);
	   }
	}
       break;
    case GIFREAD_DETAIL_BACKGROUND:
	{ int v;
	  v = va_arg(ap,int);
	  if (cmap)
	   { printf("\t\tbackground: %d [%d,%d,%d]\n",v,cmap[v][0],cmap[v][1],cmap[v][2]);
	   }
	  else
	   { printf("\t\tbackground: %d\n",v);
	   }
	}
       break;
    case GIFREAD_DETAIL_CMAP:
	{ int gbl;
	  int lgents;
	  unsigned char *ents;
	  unsigned char (*map)[3];
	  int i;
	  int n;
	  gbl = va_arg(ap,int);
	  lgents = va_arg(ap,int);
	  ents = va_arg(ap,unsigned char *);
	  map = (void *)ents;
	  printf("%s cmap (lgents = %d):",gbl?"global":"local",lgents);
	  n = 1 << lgents;
	  for (i=0;i<n;i++) printf(" (%d,%d,%d)",map[i][0],map[i][1],map[i][2]);
	  printf("\n");
	  if (gbl) gcmap = map; else lcmap = map;
	  cmap = lcmap ? : gcmap;
	}
       break;
  }
 va_end(ap);
}

static GIFREADER_OPS gr_ops = GIFREADER_OPS_INIT(gifdump);

int main(void);
int main(void)
{
 gr = gifreader_open(&gr_ops,0,GIFREAD_DETAIL_ALL);
 gcmap = 0;
 lcmap = 0;
 cmap = 0;
 gifreader_read(gr);
 gifreader_done(gr);
 return(0);
}

//  unsigned char *screen;
//static void clear_to_bg(GIFREADER *gr)
//{
// int n;
// int i;
//
// n = gr->scr_w * gr->scr_h;
// if (n < 1) return;
// bcopy(&gr->global_map[gr->scr_bg&((1<<(gr->scr_pix+1))-1)][0],&gr->screen[0],3);
// if (n < 2) return;
// i = 0;
// while ((1 << (i + 1)) < n)
//  { bcopy(&gr->screen[0],&gr->screen[3<<i],3<<i);
//    i ++;
//  }
// bcopy(&gr->screen[0],&gr->screen[3<<i],3*(n-(1<<i)));
//}
// gr->screen = 0;
// gr->screen = malloc(gr->scr_w*gr->scr_h*3);
// if (! gr->screen)
//  { gr_err(gr,GIFREAD_ERR_NOMEM,gr->scr_w*gr->scr_h*3);
//    return;
//  }
// if (gr->scr_m) clear_to_bg(gr);
//
//
//do this upon GIFREAD_DETAIL_SCRDESC or a zero-size GIFREAD_DETAIL_LZW_DATA
//static void clear_graphic_extension(GIFREADER *gr)
//{
//  int gx_disposal;
//  int gx_userin;
//  int gx_delay;
//  int gx_transparent;
// gr->gx_disposal = GIFREAD_GX_DISP_NONE;
// gr->gx_userin = 0;
// gr->gx_delay = 0;
// gr->gx_transparent = -1;
//}