/*  @Revision: 1.9 @
**
**  Do shell-style pattern matching for ?, \, [], and * characters.
**  Might not be robust in face of malformed patterns; e.g., "foo[a-"
**  could cause a segmentation violation.  It is 8bit clean.
**
**  Written by Rich $alz, mirror!rs, Wed Nov 26 19:03:17 EST 1986.
**  Rich $alz is now <rsalz@osf.org>.
**  April, 1991:  Replaced mutually-recursive calls with in-line code
**  for the star character.
**
**  Special thanks to Lars Mathiesen <thorinn@diku.dk> for the ABORT code.
**  This can greatly speed up failing wildcard patterns.  For example:
**	pattern: -*-*-*-*-*-*-12-*-*-*-m-*-*-*
**	text 1:	 -adobe-courier-bold-o-normal--12-120-75-75-m-70-iso8859-1
**	text 2:	 -adobe-courier-bold-o-normal--12-120-75-75-X-70-iso8859-1
**  Text 1 matches with 51 calls, while text 2 fails with 54 calls.  Without
**  the ABORT code, it takes 22310 calls to fail.  Ugh.  The following
**  explanation is from Lars:
**  The precondition that must be fulfilled is that DoMatch will consume
**  at least one character in text.  This is true if *p is neither '*' nor
**  '\0'.)  The last return has ABORT instead of FALSE to avoid quadratic
**  behavior in cases like pattern "*a*b*c*d" with text "abcxxxxx".  With
**  FALSE, each star-loop has to run to the end of the text; with ABORT
**  only the last one does.
**
**  Once the control of one instance of DoMatch enters the star-loop, that
**  instance will return either TRUE or ABORT, and any calling instance
**  will therefore return immediately after (without calling recursively
**  again).  In effect, only one star-loop is ever active.  It would be
**  possible to modify the code to maintain this context explicitly,
**  eliminating all recursive calls at the cost of some complication and
**  loss of clarity (and the ABORT stuff seems to be unclear enough by
**  itself).  I think it would be unwise to try to get this into a
**  released version unless you have a good test data base to try it out
**  on.
*/

#ifndef TIN_H
#	include "tin.h"
#endif /* !TIN_H */

#define ABORT	-1

/* What character marks an inverted character class? */
#define NEGATE_CLASS	'^'

/* Is "*" a common pattern? */
#define OPTIMIZE_JUST_STAR 1

/* Do tar(1) matching rules, which ignore a trailing slash? */
#undef MATCH_TAR_PATTERN

/*
 * local prototypes
 */
static int DoMatch(const char *text, char *p);

/*
 *  Match text and p, return 1 (TRUE), 0 (FALSE), or -1 (ABORT).
 */

static int
DoMatch(
	const char *text,
	char *p)
{
	int last;
	int matched;
	int reverse;

	for (; *p; text++, p++) {
		if (*text == '\0' && *p != '*')
			return ABORT;
		switch (*p) {
			case '\\':
				/* Literal match with following character. */
				p++;
				/* FALLTHROUGH */
			default:
				if (*text != *p)
					return 0;
				continue;
			case '?':
				/* Match anything. */
				continue;
			case '*':
				while (*++p == '*')
					/* Consecutive stars act just like one. */
					continue;
				if (*p == '\0')
					/* Trailing star matches everything. */
					return 1;
				while (*text)
					if ((matched = DoMatch(text++, p)) != 0)
						return matched;
				return ABORT;
			case '[':
				reverse = p[1] == NEGATE_CLASS ? TRUE : FALSE;
				if (reverse)
					/* Inverted character class. */
					p++;
				matched = FALSE;
				if (p[1] == ']' || p[1] == '-')
					if (*++p == *text)
						matched = TRUE;
				for (last = *p; *++p && *p != ']'; last = *p)
					/* This next line requires a good C compiler. */
					if (*p == '-' && p[1] != ']' ? *text <= *++p && *text >= last : *text == *p)
						matched = TRUE;
				if (matched == reverse)
					return 0;
				continue;
			}
		}
#ifdef MATCH_TAR_PATTERN
		if (*text == '/')
			return 1;
#endif /* MATCH_TAR_PATTERN */
	return *text == '\0';
}


/*
 * User-level routine. Returns TRUE or FALSE.
 */
t_bool
wildmat(
	const char *text,
	char *p,
	t_bool icase)
{
	char *txt;
	t_bool ret;

	/*
	 * Make sure the pattern is not NULL
	 */
	if (p == NULL || text == NULL)
		return FALSE;
#ifdef OPTIMIZE_JUST_STAR
	if (p[0] == '*' && p[1] == '\0')
		return TRUE;
#endif /* OPTIMIZE_JUST_STAR */

	if (icase) {
		txt = my_strdup(text);
		str_lwr(txt);
		str_lwr(p);
		ret = (DoMatch(txt, p) == TRUE);
		free(txt);
	} else
		ret = (DoMatch(text, p) == TRUE);

	return ret;
}


/*
 * User-level routine. Calculates position of a match within a line.
 * Returns TRUE or FALSE.
 */
t_bool
wildmatpos(
	const char *text,
	char *p,
	t_bool icase,
	REGEX_SIZE *srch_offsets,
	REGEX_NOFFSET srch_offsets_size)
{
	char *txt, *t, *px;
	size_t i;
	REGEX_SIZE prev_offset = srch_offsets[1];
	t_bool ret = FALSE;

	if (srch_offsets_size >= 2)
		srch_offsets[0] = srch_offsets[1] = 0;

	/*
	 * Make sure the pattern is not NULL
	 */
	if (p == NULL || text == NULL)
		return FALSE;
#ifdef OPTIMIZE_JUST_STAR
	if (p[0] == '*' && p[1] == '\0') {
		if (srch_offsets_size >= 2) {
			srch_offsets[0] = 0;
			srch_offsets[1] = (REGEX_SIZE) strlen(text);
		}
		return TRUE;
	}
#endif /* OPTIMIZE_JUST_STAR */

	txt = my_strdup(text);
	if (icase) {
		str_lwr(txt);
		str_lwr(p);
	}

	/* remove the leading '*' */
	px = my_strdup(p + 1);

	for (t = txt + prev_offset; *t; t++) {
		if ((ret = (DoMatch(t, px) == 1))) {
			/* remove the trailing '*' */
			px[strlen(px) - 1] = '\0';
			for (i = strlen(t); i > 0; i--) {
				t[i] = '\0';
				if ((ret = (DoMatch(t, px) == 1))) {
					if (srch_offsets_size >= 2) {
						srch_offsets[0] = (REGEX_SIZE) (t - txt);
						srch_offsets[1] = srch_offsets[0] + i;
					}
					break;
				}
			}
			break;
		}
	}
	free(px);
	free(txt);

	return ret;
}
