#include <string.h>
#include <libowfat/str.h>
#include <libowfat/uint32.h>
#include "bstr.h"

int bstr_diff2(const char* a,const char* b,size_t blen) {
  const char* A,* B;
  int j;
  /* like str_diff, just for bstrs */
  if (*a)
    A=a+str_len(a);
  else {
    A=a+5+uint32_read(a+1);
    a+=5;
  }
  B=b+blen;
  for (;;) {
    if (a==A) {
      if (b==B)
	return 0;
      else
	return -1;
    } else
      if (b==B)
	return 1;
    if ((j=((unsigned char)*a-(unsigned char)*b))) break;
    ++a; ++b;
  }
  return j;
}

#ifdef UNITTEST
#include <assert.h>

int main() {
  assert(bstr_diff2("bar","foo",3) < 0);
  assert(bstr_diff2("foo","bar",3) > 0);
  assert(bstr_diff2("foo1","foo",3) > 0);
  assert(bstr_diff2("foo","foo1",4) < 0);
  assert(bstr_diff2("foo","foo",3) == 0);

  assert(bstr_diff2("\x00\x03\x00\x00\x00""bar","foo",3) < 0);
  assert(bstr_diff2("\x00\x03\x00\x00\x00""foo","bar",3) > 0);
  assert(bstr_diff2("\x00\x04\x00\x00\x00""foo1","foo",3) > 0);
  assert(bstr_diff2("\x00\x03\x00\x00\x00""foo","foo1",4) < 0);
  assert(bstr_diff2("\x00\x03\x00\x00\x00""foo","foo",3) == 0);

  assert(bstr_diff2("\x00\x03\x00\x00\x00""bar","foo",3) < 0);
  assert(bstr_diff2("\x00\x03\x00\x00\x00""foo","bar",3) > 0);
  assert(bstr_diff2("\x00\x04\x00\x00\x00""foo1","foo",3) > 0);
  assert(bstr_diff2("\x00\x03\x00\x00\x00""foo","foo1",4) < 0);
  assert(bstr_diff2("\x00\x03\x00\x00\x00""foo","foo",3) == 0);

  assert(bstr_diff2("\x00\x05\x00\x00\x00""f\x00ord","fnord",5) < 0);
  assert(bstr_diff2("\x00\x05\x00\x00\x00""f\x00ord","f\x00ort",5) < 0);

  assert(bstr_diff2("\x00\x03\x00\x00\x00""f\xf6o","foo",3) > 0);
}
#endif