/*
 * tclUtf.c --
 *
 *	Routines for manipulating UTF-8 strings.
 *
 * Copyright (c) 1997-1998 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * RCS: @(#) $Id: tclUtf.c,v 1.11 2000/01/11 22:09:00 hobbs Exp $
 * RCS: @(#) $Id: tclUtf.c,v 1.12 2000/05/08 21:59:58 hobbs Exp $
 */

#include "tclInt.h"

/*
 * Include the static character classification tables and macros.
 */

Tcl_UniCharNcmp(cs, ct, n)
    CONST Tcl_UniChar *cs;		/* Unicode string to compare to ct. */
    CONST Tcl_UniChar *ct;		/* Unicode string cs is compared to. */
    unsigned long n;			/* Number of unichars to compare. */
{
    for ( ; n != 0; n--, cs++, ct++) {
	if (*cs != *ct) {
	    return (*cs - *ct);
	}
	if (*cs == '\0') {
	    break;
	}
    }
	    return *cs - *ct;
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_UniCharNcasecmp --
 *
 *	Compare at most n unichars of string cs to string ct case
 *	insensitive.  Both cs and ct are assumed to be at least n
 *	unichars long.
 *
 * Results:
 *	Return <0 if cs < ct, 0 if cs == ct, or >0 if cs > ct.
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_UniCharNcasecmp(cs, ct, n)
    CONST Tcl_UniChar *cs;		/* Unicode string to compare to ct. */
    CONST Tcl_UniChar *ct;		/* Unicode string cs is compared to. */
    unsigned long n;			/* Number of unichars to compare. */
{
    for ( ; n != 0; n--, cs++, ct++) {
	if ((*cs != *ct) &&
		(Tcl_UniCharToLower(*cs) != Tcl_UniCharToLower(*ct))) {
	    return (*cs - *ct);
	}
	if (*cs == '\0') {
	    break;
	}
    }
    return 0;
}

Tcl_UniCharIsWordChar(ch)
    int ch;			/* Unicode character to test. */
{
    register int category = (GetUniCharInfo(ch) & UNICODE_CATEGORY_MASK);

    return (((ALPHA_BITS | DIGIT_BITS | CONNECTOR_BITS) >> category) & 1);
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_UniCharCaseMatch --
 *
 *	See if a particular Unicode string matches a particular pattern.
 *	Allows case insensitivity.  Thie is the Unicode equivalent of
 *	the char* Tcl_StringCaseMatch.
 *
 * Results:
 *	The return value is 1 if string matches pattern, and
 *	0 otherwise.  The matching operation permits the following
 *	special characters in the pattern: *?\[] (see the manual
 *	entry for details on what these mean).
 *
 * Side effects:
 *	None.
 *
 *----------------------------------------------------------------------
 */

int
Tcl_UniCharCaseMatch(string, pattern, nocase)
    CONST Tcl_UniChar *string;	/* Unicode String. */
    CONST Tcl_UniChar *pattern;	/* Pattern, which may contain special
				 * characters. */
    int nocase;			/* 0 for case sensitive, 1 for insensitive */
{
    Tcl_UniChar ch1, p;
    
    while (1) {
	p = *pattern;
	
	/*
	 * See if we're at the end of both the pattern and the string.  If
	 * so, we succeeded.  If we're at the end of the pattern but not at
	 * the end of the string, we failed.
	 */
	
	if (p == 0) {
	    return (*string == 0);
	}
	if ((*string == 0) && (p != '*')) {
	    return 0;
	}

	/*
	 * Check for a "*" as the next pattern character.  It matches any
	 * substring.  We handle this by skipping all the characters up to the
	 * next matching one in the pattern, and then calling ourselves
	 * recursively for each postfix of string, until either we match or we
	 * reach the end of the string.
	 */
	
	if (p == '*') {
	    int pSpecial;
	    /*
	     * Skip all successive *'s in the pattern
	     */
	    while (*(++pattern) == '*') {}
	    p = *pattern;
	    if (p == 0) {
		return 1;
	    }
	    while (1) {
		/*
		 * Optimization for matching - cruise through the string
		 * quickly if the next char in the pattern isn't a special
		 * character
		 */
		if ((p != '[') && (p != '?') && (p != '\\')) {
		    if (nocase) {
			while (*string && (p != *string)
				&& (p != Tcl_UniCharToLower(*string))) {
			    string++;
			}
		    } else {
			while (*string && (p != *string)) { string++; }
		    }
		}
		if (Tcl_UniCharCaseMatch(string, pattern, nocase)) {
		    return 1;
		}
		if (*string == 0) {
		    return 0;
		}
		string++;
	    }
	}

	/*
	 * Check for a "?" as the next pattern character.  It matches
	 * any single character.
	 */

	if (p == '?') {
	    pattern++;
	    string++;
	    continue;
	}

	/*
	 * Check for a "[" as the next pattern character.  It is followed
	 * by a list of characters that are acceptable, or by a range
	 * (two characters separated by "-").
	 */
	
	if (p == '[') {
	    Tcl_UniChar startChar, endChar;

	    pattern++;
	    ch1 = (nocase ? Tcl_UniCharToLower(*string) : *string);
	    string++;
	    while (1) {
		if ((*pattern == ']') || (*pattern == 0)) {
		    return 0;
		}
		startChar = (nocase ? Tcl_UniCharToLower(*pattern) : *pattern);
		pattern++;
		if (*pattern == '-') {
		    pattern++;
		    if (*pattern == 0) {
			return 0;
		    }
		    endChar = (nocase ? Tcl_UniCharToLower(*pattern)
			    : *pattern);
		    pattern++;
		    if (((startChar <= ch1) && (ch1 <= endChar))
			    || ((endChar <= ch1) && (ch1 <= startChar))) {
			/*
			 * Matches ranges of form [a-z] or [z-a].
			 */
			break;
		    }
		} else if (startChar == ch1) {
		    break;
		}
	    }
	    while (*pattern != ']') {
		if (*pattern == 0) {
		    pattern--;
		    break;
		}
		pattern++;
	    }
	    pattern++;
	    continue;
	}

	/*
	 * If the next pattern character is '\', just strip off the '\'
	 * so we do exact matching on the character that follows.
	 */

	if (p == '\\') {
	    if (*(++pattern) == '\0') {
		return 0;
	    }
	}

	/*
	 * There's no special character.  Just make sure that the next
	 * bytes of each string match.
	 */

	if (nocase) {
	    if (Tcl_UniCharToLower(*string) != Tcl_UniCharToLower(*pattern)) {
		return 0;
	    }
	} else if (*string != *pattern) {
	    return 0;
	}
	string++;
	pattern++;
    }
}