#include "libft.h"
#include "test_utils.h"

_S_CRASH (ft_substr_null, ft_substr (NULL, 0, 5))

static void
_s_test_substr (void)
{
  int i;
  char label[128];

  _s_section ("ft_substr");

  /* NULL crashes */
  _s_check ("NULL crashes", _s_crashes (_s_crash_ft_substr_null));

  /* basic substring from the middle */
  {
    char *p = ft_substr ("hello world", 6, 5);
    _s_check ("middle", p && strcmp (p, "world") == 0);
    free (p);
  }

  /* from the start */
  {
    char *p = ft_substr ("hello", 0, 3);
    _s_check ("from start", p && strcmp (p, "hel") == 0);
    free (p);
  }

  /* len larger than remaining string */
  {
    char *p = ft_substr ("hello", 2, 100);
    _s_check ("len > remaining", p && strcmp (p, "llo") == 0);
    free (p);
  }

  /* start beyond string length */
  {
    char *p = ft_substr ("hello", 10, 5);
    _s_check ("start > slen", p && strcmp (p, "") == 0);
    free (p);
  }

  /* start == string length */
  {
    char *p = ft_substr ("hello", 5, 5);
    _s_check ("start == slen", p && strcmp (p, "") == 0);
    free (p);
  }

  /* empty source string */
  {
    char *p = ft_substr ("", 0, 10);
    _s_check ("empty src", p && strcmp (p, "") == 0);
    free (p);
  }

  /* len == 0 */
  {
    char *p = ft_substr ("hello", 0, 0);
    _s_check ("len=0", p && strcmp (p, "") == 0);
    free (p);
  }

  /* full string copy */
  {
    char *p = ft_substr ("hello", 0, 5);
    _s_check ("full copy", p && strcmp (p, "hello") == 0);
    free (p);
  }

  /* single character */
  {
    char *p = ft_substr ("hello", 4, 1);
    _s_check ("single char", p && strcmp (p, "o") == 0);
    free (p);
  }

  /* returns independent copy */
  {
    char src[] = "hello";
    char *p = ft_substr (src, 0, 5);
    _s_check ("independent ptr", p && p != src);
    free (p);
  }

  /* randomized */
  for (i = 0; i < _S_RAND_ITERS; i++)
    {
      int slen = rand () % 200 + 1;
      char *src = malloc (slen + 1);
      unsigned int start;
      size_t len;
      char *p;
      int j;

      if (!src)
        continue;
      for (j = 0; j < slen; j++)
        src[j] = 'A' + rand () % 26;
      src[slen] = '\0';

      start = rand () % (slen + 5);
      len = rand () % (slen + 5);
      p = ft_substr (src, start, len);

      if (start >= (unsigned int)slen)
        {
          snprintf (label, sizeof (label), "random start=%u >= slen=%d", start,
                    slen);
          _s_check (label, p && strcmp (p, "") == 0);
        }
      else
        {
          size_t remaining = slen - start;
          size_t expected = remaining < len ? remaining : len;
          snprintf (label, sizeof (label), "random start=%u len=%zu slen=%d",
                    start, len, slen);
          _s_check (label, p && strlen (p) == expected
                               && strncmp (p, src + start, expected) == 0);
        }
      free (p);
      free (src);
    }
}

int
main (void)
{
  srand (time (NULL));
  _s_test_substr ();
  _s_print_results ();
  return (_s_fail != 0);
}