#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include "crc32.h"

void help() {
  printf("-x -X -d -h\n");
  exit(EXIT_FAILURE);
}

int main (int argc, char *argv[]) {
  int c;
  FILE * fp;
  uint32_t crc;
  unsigned char *fmt = "%08x\t%s\n";
  int prog_return = EXIT_SUCCESS;

  int blksz = 4096;
  unsigned char bufr[blksz];
  
  while (( c = getopt(argc, argv, "hXxd")) != -1) {
    switch (c) {
      case 'x':
        fmt = "%08x\t%s\n";
	break;
      case 'X':
        fmt = "%08X\t%s\n";
	break;
      case 'd':
        fmt = "%d\t%s\n";
	break;
      case 'h':
      case '?':
        help();
        break;
    }
  }
  
  chksum_crc32_gentab();
  
  if (optind == argc) {
    crc = 0;
    while (!feof(stdin)) {
      if ((c = fread(bufr, 1, blksz, stdin)) > 0) {
        chksum_crc32(bufr, c, &crc);
      }
    }
    printf(fmt, crc, "-");
  } else {  
    for ( ; optind < argc; optind++) {
      if (0 == strcmp("-", argv[optind])) {
        crc = 0;
        while (!feof(stdin)) {
          if ((c = fread(bufr, 1, blksz, stdin)) > 0) {
            chksum_crc32(bufr, c, &crc);
          }
        }
        printf(fmt, crc, "-");
      } else if (access(argv[optind], R_OK) == 0) {
        crc = 0;
	if (fp = fopen(argv[optind], "r")) {
	  while (!feof(fp))
	    if ((c = fread(bufr, 1, blksz, fp)) > 0)
	      chksum_crc32(bufr, c, &crc);
	} else {
	  strerror();
	}
        printf(fmt, crc, argv[optind]);
      } else {
        fprintf(stderr, "NG: %s\n", argv[optind]);
	prog_return++;
      }
    }
  }
  exit(prog_return);
}