#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "fio.h"
#include "error.h"
#include "tags.h"

/* $Id : $Exp */

int
TAGskip(FILE *fp, int tag, long long len)
{
#if 1
  unsigned char *buf ;
  int ret ;

  buf = (unsigned char *)calloc(len, sizeof(unsigned char)) ;
  if (buf==NULL) 
    ErrorExit(ERROR_NOMEMORY,
	      "TAGskip: failed to calloc %u bytes!\n",len);
  ret = fread(buf, sizeof(unsigned char), len, fp) ;
  free(buf) ;
  return(ret) ;
#else
  return(fseek(fp, len, SEEK_CUR)) ;  // doesn't work for gzipped files
#endif
}
int
TAGreadStart(FILE *fp, long long *plen)
{
  int  tag ;

  tag = freadInt(fp) ;
  if (feof(fp))
    return(0) ;
  switch (tag)
    {
    case TAG_OLD_MGH_XFORM:
      *plen = (long long)freadInt(fp) ;  /* sorry - backwards compatibility
                                            with Tosa's stuff */
      *plen = *plen -1 ; // doesn't include null
      break ;
    case TAG_OLD_SURF_GEOM:    // these don't take lengths at all
    case TAG_OLD_USEREALRAS:
    case TAG_OLD_COLORTABLE:
      *plen = 0 ;
      break ;
    default:
      *plen = freadLong(fp) ;
    }

  return(tag) ;
}

int
TAGwriteStart(FILE *fp, int tag, long long *phere, long long len)
{
  long here ;

  fwriteInt(tag, fp) ;

  here = ftell(fp) ;
  *phere = (long long)here ;
  fwriteLong(len, fp) ;

  return(NO_ERROR) ;
}

int
TAGwrite(FILE *fp, int tag, void *buf, long long len)
{
  long long here ;

  TAGwriteStart(fp, tag, &here, len) ;
  fwrite(buf, sizeof(char), len, fp) ;
  TAGwriteEnd(fp, here) ;
  return(NO_ERROR) ;
}

int
TAGwriteEnd(FILE *fp, long long there)
{
  long long here ;

  here = ftell(fp) ;
#if 0
  fseek(fp, there, SEEK_SET) ;
  fwriteLong((long long)(here-(there+sizeof(long long))), fp) ;
  fseek(fp, here, SEEK_SET) ;
#endif

  return(NO_ERROR) ;
}

int
TAGmakeCommandLineString(int argc, char **argv, char *cmd_line)
{
  int i ;

  cmd_line[0] = 0 ;
  for (i = 0 ; i < argc ; i++)
    {
      strcat(cmd_line, argv[i]) ;
      strcat(cmd_line, " ") ;
    }
  return(NO_ERROR) ;
}

int
TAGwriteCommandLine(FILE *fp, char *cmd_line)
{
  long long here ;

  TAGwriteStart(fp, TAG_CMDLINE, &here, strlen(cmd_line)+1) ;
  fprintf(fp, "%s", cmd_line) ;
  TAGwriteEnd(fp, here) ;
  return(NO_ERROR) ;
}