/* Test of case-insensitive searching in a string.
   Copyright (C) 2007, 2008 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */

#include <config.h>

#include <string.h>

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#define ASSERT(expr) \
  do									     \
    {									     \
      if (!(expr))							     \
        {								     \
          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
          fflush (stderr);						     \
          abort ();							     \
        }								     \
    }									     \
  while (0)

int
main ()
{
#if HAVE_DECL_ALARM
  /* Declare failure if test takes too long, by using default abort
     caused by SIGALRM.  All known platforms that lack alarm also lack
     strcasestr, and the replacement memmem is known to not take too
     long.  */
  signal (SIGALRM, SIG_DFL);
  alarm (50);
#endif

  {
    const char input[] = "foo";
    const char *result = strcasestr (input, "");
    ASSERT (result == input);
  }

  {
    const char input[] = "foo";
    const char *result = strcasestr (input, "O");
    ASSERT (result == input + 1);
  }

  {
    const char input[] = "ABC ABCDAB ABCDABCDABDE";
    const char *result = strcasestr (input, "ABCDaBD");
    ASSERT (result == input + 15);
  }

  {
    const char input[] = "ABC ABCDAB ABCDABCDABDE";
    const char *result = strcasestr (input, "ABCDaBE");
    ASSERT (result == NULL);
  }

  {
    const char input[] = "ABC ABCDAB ABCDABCDABDE";
    const char *result = strcasestr (input, "ABCDaBCD");
    ASSERT (result == input + 11);
  }

  /* Check that a very long haystack is handled quickly if the needle is
     short and occurs near the beginning.  */
  {
    size_t repeat = 10000;
    size_t m = 1000000;
    char *needle =
      "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
      "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaAaaaaaaAAAAaaaaaaa"
      "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
    char *haystack = (char *) malloc (m + 1);
    if (haystack != NULL)
      {
	memset (haystack, 'A', m);
	haystack[0] = 'B';
	haystack[m] = '\0';

	for (; repeat > 0; repeat--)
	  {
	    ASSERT (strcasestr (haystack, needle) == haystack + 1);
	  }

	free (haystack);
      }
  }

  /* Check that a very long needle is discarded quickly if the haystack is
     short.  */
  {
    size_t repeat = 10000;
    size_t m = 1000000;
    char *haystack =
      "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"
      "ABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABABAB";
    char *needle = (char *) malloc (m + 1);
    if (needle != NULL)
      {
	memset (needle, 'A', m);
	needle[m] = '\0';

	for (; repeat > 0; repeat--)
	  {
	    ASSERT (strcasestr (haystack, needle) == NULL);
	  }

	free (needle);
      }
  }

  /* Check that the asymptotic worst-case complexity is not quadratic.  */
  {
    size_t m = 1000000;
    char *haystack = (char *) malloc (2 * m + 2);
    char *needle = (char *) malloc (m + 2);
    if (haystack != NULL && needle != NULL)
      {
	const char *result;

	memset (haystack, 'A', 2 * m);
	haystack[2 * m] = 'B';
	haystack[2 * m + 1] = '\0';

	memset (needle, 'a', m);
	needle[m] = 'B';
	needle[m + 1] = '\0';

	result = strcasestr (haystack, needle);
	ASSERT (result == haystack + m);
      }
    free (needle);
    free (haystack);
  }

  return 0;
}