#include "nibble.h"
#include <stdio.h>

bcd bcd_zeros() {
  bcd bcd;
  memset(bcd.internal, 0, sizeof(bcd.internal));
  return bcd;
}

#define bcd_from_n(X) {\
  int i;\
  bcd res = bcd_zeros();\
  for (i = 9; i >= 0; --i) {\
    if (!X) break;\
    res.internal[i] = (X % 10);\
    X /= 10;\
    if (!X) break;\
    res.internal[i] += (X % 10) << 4;\
    X /= 10;\
  }\
  return res;\
}

bcd bcd_from_8(uint8_t x) {
  bcd_from_n(x);
}

bcd bcd_from_16(uint16_t x) {
  bcd_from_n(x);
}

bcd bcd_from_32(uint32_t x) {
  bcd_from_n(x);
}

bcd bcd_from_64(uint64_t x) {
  bcd_from_n(x);
}

uint8_t bcd_digits(bcd x) {
  int i;
  for (i = 0; i < 20; i+=2) {
    if (x.internal[i/2] != 0) {
      if (!(x.internal[i/2]&0xf0)) i++;
      break;
    }
  }
  return 20-i;
}

uint64_t bcd_to_64(bcd x) {
  int i;
  uint64_t res = 0;

  for (i = 0; i < 10; ++i) {
    res *= 100;
    res += ((x.internal[i] & 0xf0) >> 4) * 10;
    res += (x.internal[i] & 0xf);
  }

  return res;
}

char* bcd_to_string(bcd x) {
  int i = 0;
  uint8_t n = bcd_digits(x);
  int to = 10-(n+1)/2;
  char* res = malloc(n+1);

  for (i = 0; i < n; i+=2, to++) {
    res[i]   = ((x.internal[to] & 0xf0) >> 4) + '0';
    res[i+1] = (x.internal[to] & 0xf) + '0';
  }

  res[n] = '\0';
  return res;
}