#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <strings.h>
#include <sys/file.h>

extern const char *__progname;

static char tfn[64];

static FILE *tf;

static char *makeppsym(const char *fn, unsigned long int chksum)
{
 const char *fp;
 char *tp;
 char *ppsym;
 int i;
 typedef unsigned char UC;

 fp = rindex(fn,'/');
 if (fp) fp ++; else fp = fn;
 ppsym = malloc(1+strlen(fn)+1+8+1);
 tp = ppsym;
 *tp++ = '_';
 for (;*fp;fp++)
  {      if (!isascii(*fp) || !isalnum((UC)*fp)) *tp++ = '_';
    else if (islower((UC)*fp)                  ) *tp++ = toupper((UC)*fp);
    else                                         *tp++ = *fp;
  }
 *tp++ = '_';
 for (i=28;i>=0;i-=4)
  { *tp++ = "0123456789abcdef"[chksum&0xf];
    chksum >>= 4;
  }
 *tp++ = '_';
 *tp = '\0';
 return(ppsym);
}

static void dowrap(const char *fn)
{
 FILE *ff;
 char *ppsym;
 int skip;
 int ppl;
 char *filebeg;
 char *tfilebeg;
 char *savfilebeg;
 unsigned int nfb;
 unsigned int fbx;
 char fileend[16];
 unsigned int fex;
 int c;
 int i;
 unsigned long int chksum;
 unsigned long int ichksum;

 ff = fopen(fn,"r+");
 if (ff == 0)
  { fprintf(stderr,"%s: can't open %s\n",__progname,fn);
    return;
  }
 ppsym = makeppsym(fn,0);
 ppl = strlen(ppsym);
 nfb = (ppl * 2) + 19;
 filebeg = malloc((nfb+1)*3);
 tfilebeg = filebeg + nfb + 1;
 savfilebeg = tfilebeg + nfb + 1;
 fbx = 0;
 fex = 0;
 chksum = 0;
 ichksum = 0;
 i = 0;
 while (1)
  { c = getc(ff);
    if (c == EOF) break;
    /* note: assumes stuff saved in fileend is shorter than filebeg!
       otherwise, ichksum will use as-yet-unset fileend[] elements. */
    fex = (fex + 1) % 8;
    if (fbx < nfb)
     { filebeg[fbx++] = c;
     }
    else
     { if (i < 8)
	{ i ++;
	}
       else
	{ ichksum ^= fileend[fex];
	  ichksum = (ichksum & 1) ? (ichksum >> 1) ^ 0xedb88320 : (ichksum >> 1);
	}
     }
    chksum ^= c;
    chksum = (chksum & 1) ? (chksum >> 1) ^ 0xedb88320 : (chksum >> 1);
    fileend[fex] = c;
  }
 if (ferror(ff))
  { fprintf(stderr,"%s: error reading %s - not changed\n",__progname,fn);
    fclose(ff);
    free(filebeg);
    return;
  }
 if ((fbx > 18) && !bcmp(filebeg,"/* NO WRAPHFILE */",18))
  { fclose(ff);
    free(filebeg);
    return;
  }
 sprintf(tfilebeg,"#ifndef %s\n#define %s\n\n",ppsym,ppsym);
 skip = 0;
 if (fbx >= nfb)
  { bcopy(filebeg,savfilebeg,nfb);
    bcopy("00000000",filebeg+8+ppl-9,8);
    bcopy("00000000",filebeg+8+ppl+9+ppl-9,8);
    if (! bcmp(filebeg,tfilebeg,nfb))
     { for (i=15;i>=8;i--)
	{ fileend[i] = fileend[fex];
	  fex = (fex + 7) % 8;
	}
       if (! bcmp(&fileend[8],"\n#endif\n",8))
	{ ppsym = makeppsym(fn,ichksum);
	  if ( !bcmp(savfilebeg+8,ppsym,ppl) &&
	       !bcmp(savfilebeg+8+ppl+9,ppsym,ppl) )
	   { fclose(ff);
	     free(filebeg);
	     return;
	   }
	  skip = nfb;
	}
     }
  }
 if (! skip) ppsym = makeppsym(fn,chksum);
 rewind(ff);
 rewind(tf);
 fprintf(tf,"#ifndef %s\n#define %s\n\n",ppsym,ppsym);
 if (skip)
  { for (i=0;i<skip;i++) getc(ff);
    for (i=0;i<8;i++) fileend[i] = getc(ff);
    fex = 0;
    while ((c=getc(ff)) != EOF)
     { putc(fileend[fex],tf);
       fileend[fex] = c;
       fex = (fex + 1) % 8;
     }
  }
 else
  { while ((c=getc(ff)) != EOF) putc(c,tf);
  }
 if (ferror(ff))
  { fprintf(stderr,"%s: error reading %s - not changed\n",__progname,fn);
    fclose(ff);
    free(filebeg);
    return;
  }
 fprintf(tf,"\n#endif\n");
 fflush(tf);
 i = ftell(tf);
 rewind(tf);
 rewind(ff);
 for (;i>0;i--)
  { c = getc(tf);
    if (c == EOF) break;
    putc(c,ff);
  }
 if (ferror(tf))
  { fprintf(stderr,"%s: error reading temp file - %s may be corrupted\n",
						__progname,fn);
  }
 fclose(ff);
 free(filebeg);
}

int main(int, char **);
int main(int ac, char **av)
{
 sprintf(tfn,"/tmp/wraphfile.%d",getpid());
 tf = fopen(tfn,"w+");
 if (tf == 0)
  { fprintf(stderr,"%s: can't open temporary file %s\n",__progname,tfn);
    exit(1);
  }
 unlink(tfn);
 for (ac--,av++;ac;ac--,av++)
  { dowrap(av[0]);
  }
 exit(0);
}