/* fnmatch.cc: Filename amtch

   Copyright 2001 Red Hat, Inc.
   Copyright 2001 Red Hat, Inc.

   Written by Robert Collins <rbtcollins@hotmail.com>
   
   This file is part of Cygwin.

   This software is a copyrighted work licensed under the terms of the
   Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
   details. */

#include <fnmatch.h>

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "winsup.h"
#include <errno.h>
#include "cygerrno.h"
#include <assert.h>

/* compare pattern against string.
 * logic: iterate across pattern incrementing string
 * as appropriate.
 * for *, we skip across any following * or ? characters,
 * incrementing the string location for ?, 
 * and then try to match the following component against the remaining string.
 * but allowing it to slide to the right by up to 
 * len (rem string) - (len (remaining pattern)
 */
extern "C" int
fnmatch (const char *pattern, const char *string, int flags)
{
  const char *p = pattern, *s = string;
  char current;
  while ((current = *p++) != '\0')
    {
      switch (current)
	{
	case '?':
	  if ((*s == '\0') ||
	      ((flags & FNM_PATHNAME) && *s == '/') ||
	      (((flags & FNM_PERIOD) && *s == '.') &&
	       ((s == string) || ((flags & FNM_PATHNAME) && s[-1] == '/'))))
	    return FNM_NOMATCH;
	  s++;
	  break;

	case '*':
	  if (*s == '\0')
	    return 0;		// * matches NULL strings.
	  if ((flags & FNM_PERIOD) && *s == '.'
	      && ((s == string) || ((flags & FNM_PATHNAME) && s[-1] == '/')))
	    return FNM_NOMATCH;
	  /* walk through any wildcards - ** == *, and *? = * with a length minimum. */
	  for (current = *p++; current == '*' || current == '?';
	       current = *p++)
	    {
	      if ((flags & FNM_PATHNAME) && *s == '/')
		return FNM_NOMATCH;
	      // Can't get a . here, it must follow / caught aboce
	      if (current == '?')
		{
		  if (*s == '\0')
		    return FNM_NOMATCH;
		  else
		    // use up a character.
		    s++;
		}
	    }
	  if (current == '\0')
	    return 0;		// success
	  --p;			// get back a pointer to the remaining pattern
	  if (current == '\\' && !(flags & FNM_NOESCAPE))
	    {
	      current = p[1];	// preserve the location
	      if (current == '\0')
		return FNM_NOMATCH;
	    }
	  while (*s)
	    {
	      int subflags = flags & ~FNM_PERIOD;
	      if ((flags & FNM_PATHNAME) && *s == '/')
		return FNM_NOMATCH;
	      if (current == *s && (fnmatch (p, s, subflags) == 0))
		return 0;	// recursion worked
	      ++s;
	    }
	  return FNM_NOMATCH;
	case '[':
	  // Grr regexp time
	  return FNM_NOMATCH;
	  break;
//        '!' is the negatopr, not '^' as usual
	case '\\':
	  if (!(flags & FNM_NOESCAPE))
	    {
	      current = *p++;
	      if (current == '\0')
		// \ without character
		return FNM_NOMATCH;
	    }
	  if (*s == '\0' || current != *s++)
	    return FNM_NOMATCH;

	  break;
	case '|':		/* fallthru */
	case '&':		/* fallthru */
	case ';':		/* fallthru */
	case '<':		/* fallthru */
	case '>':		/* fallthru */
	case '(':		/* fallthru */
	case ')':		/* fallthru */
	case '$':		/* fallthru */
	case '\"':		/* fallthru */
	case ' ':		/* fallthru */
	case '\t':		/* fallthru */
	case '\n':		/* fallthru */
	case '#':		/* fallthru *//* these next 4 may need to be allowed */
	case '~':		/* fallthru */
	case '=':		/* fallthru */
	case '%':		/* These characters _have_ to be escaped according to
				   IEEE P1003.1, Draft 6, April 2001/ Open Group Technical Standard, Issue 6
				   2.13.1
				 */
	  return FNM_NOMATCH;

	default:
	  if (current != *s++)
	    return FNM_NOMATCH;

	}
    }

  if (*s == '\0')
    return 0;

  // Gotta love the non-posix extensions required to satisfy GNU AC tests 
  if(*s == '/' && (flags & FNM_LEADING_DIR))
    return 0;

  return FNM_NOMATCH;
}