#include "stralloc.h"

#include <stdlib.h>

#include "alloc.h"
#include "byte.h"
#include "str.h"

/**
  @file stralloc.c
  @author djb
  @ref qmail, ucspi-tcp
  @brief genious dynamic string handling
*/

int stralloc_starts(stralloc *sa, const char *s)
{
  int len;
  len = str_len(s);
  return (sa->len >= len) && byte_equal(s, len, sa->s);
}

int stralloc_cat(stralloc *sato, stralloc *safrom)
{
  return stralloc_catb(sato, safrom->s, safrom->len);
}

int stralloc_catb(stralloc *sa, const char *s, unsigned int n)
{
  if (!sa->s) return stralloc_copyb(sa, s, n);
  if (!stralloc_readyplus(sa, n + 1)) return 0;
  byte_copy(sa->s + sa->len, n, s);
  sa->len += n;
  sa->s[sa->len] = 'Z'; /* ``offensive programming'' */
  return 1;
}

int stralloc_cats(stralloc *sa, const char *s)
{
  return stralloc_catb(sa, s, str_len(s));
}

int stralloc_copy(stralloc *sato, stralloc *safrom)
{
  return stralloc_copyb(sato, safrom->s, safrom->len);
}


int stralloc_ready(stralloc *sa, size_t len)
{
  size_t wanted = len + (len >> 3) + 30; /* heuristic from djb */
  if (wanted < len) wanted = len;
  if (!sa->s || sa->a < len) {
    char *tmp;
    if (!(tmp = realloc(sa->s, wanted)))  // !!! needs stdlib (realloc)
      return 0;
    sa->a = wanted;
    sa->s = tmp;
  }
  return 1;
}

int stralloc_readyplus(stralloc *sa, size_t len)
{
  if (sa->s) {
    if (sa->len + len < len) return 0; /* catch integer overflow */
    return stralloc_ready(sa, sa->len + len);
  } else
    return stralloc_ready(sa, len);
}

int stralloc_copyb(stralloc *sa, const char *s, unsigned int n)
{
  if (!stralloc_ready(sa, n + 1)) return 0;
  byte_copy(sa->s, n, s);
  sa->len = n;
  sa->s[n] = 'Z'; /* ``offensive programming'' */
  return 1;
}

int stralloc_copys(stralloc *sa, const char *s)
{
  return stralloc_copyb(sa, s, str_len(s));
}

int stralloc_catulong0(stralloc *sa, unsigned long u, unsigned int n)
{
  unsigned int len;
  unsigned long q;
  char *s;

  len = 1;
  q = u;
  while (q > 9) {
    ++len;
    q /= 10;
  }
  if (len < n) len = n;

  if (!stralloc_readyplus(sa, len)) return 0;
  s = sa->s + sa->len;
  sa->len += len;
  while (len) {
    s[--len] = '0' + (u % 10);
    u /= 10;
  }

  return 1;
}

int stralloc_catlong0(stralloc *sa, long l, unsigned int n)
{
  if (l < 0) {
    if (!stralloc_append(sa, "-")) return 0;
    l = -l;
  }
  return stralloc_catulong0(sa, l, n);
}

int stralloc_append(stralloc *sa, const char *in)
{
  if (stralloc_readyplus(sa, 1)) {
    sa->s[sa->len] = *in;
    ++sa->len;
    return 1;
  }
  return 0;
}

void stralloc_free(stralloc *sa)
{
  if (sa->s) free(sa->s);
  sa->s = 0;
  sa->a = sa->len = 0;
}