/***
*wcsxfrm.c - Transform a wide-character string using locale information
*
*	Copyright (c) 1988-1993, Microsoft Corporation. All rights reserved.
*
*Purpose:
*	Transform a wide-character string using the locale information as set by
*	LC_COLLATE.
*
*Revision History:
*	09-09-91   ETC	Created from strxfrm.c.
*	12-09-91   ETC	Updated api; Added multithread lock.
*	12-18-91   ETC	Changed back LCMAP_SORTKEYA --> LCMAP_SORTKEY.
*	04-06-92   KRS	Fix so it works without _INTL too.
*	08-19-92   KRS	Activate use of NLS API.
*	09-02-92   SRW	Get _INTL definition via ..\crt32.def
*	12-15-92   KRS	Fix return value to match ANSI/ISO Std.
*       09-23-93   CFW   Complete re-write. Non-C locale totally broken.
*
*******************************************************************************/

#include <cruntime.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <locale.h>
#include <setlocal.h>
#include <os2dll.h>

/***
*size_t wcsxfrm() - Transform a string using locale information
*
*Purpose:
*	Transform the wide string pointed to by _string2 and place the
*	resulting wide string into the array pointed to by _string1.
*	No more than _count wide characters are placed into the
*	resulting string (including the null).
*
*	The transformation is such that if wcscmp() is applied to
*	the two transformed strings, the return value is equal to
*	the result of wcscoll() applied to the two original strings.
*	Thus, the conversion must take the locale LC_COLLATE info
*	into account.
*
*	In the C locale, wcsxfrm() simply resolves to wcsncpy()/wcslen().
*
*Entry:
*	wchar_t *_string1	= result string
*	const wchar_t *_string2	= source string
*	size_t _count		= max wide chars to move
*
*	[If _count is 0, _string1 is permitted to be NULL.]
*
*Exit:
*	Length of the transformed string (not including the terminating
*	null).	If the value returned is >= _count, the contents of the
*	_string1 array are indeterminate.
*
*Exceptions:
*	Non-standard: if OM/API error, return INT_MAX.
*
*******************************************************************************/

size_t _CRTAPI1 wcsxfrm (
	wchar_t *_string1,
	const wchar_t *_string2,
	size_t _count
	)
{
#ifndef _INTL
	if (_string1)
	    wcsncpy(_string1, _string2, _count);
	return wcslen(_string2);
#else
	int size;
        unsigned char *bbuffer;


	_mlock (_LC_COLLATE_LOCK);

	if (_lc_handle[LC_COLLATE] == _CLOCALEHANDLE) {
		_munlock (_LC_COLLATE_LOCK);
		wcsncpy(_string1, _string2, _count);
		return wcslen(_string2);
	}

        /*
         * When using LCMAP_SORTKEY, LCMapStringW handles BYTES not wide
         * chars. We use a byte buffer to hold bytes and then convert the
         * byte string to a wide char string and return this so it can be
         * compared using wcscmp(). User's buffer is _count wide chars, so
         * use an internal buffer of _count bytes.
         */

        if (NULL == (bbuffer = (unsigned char *)malloc(_count)))
        {
            size = INT_MAX;
            goto error_cleanup;
        }

        if (0 == (size = LCMapStringW(_lc_handle[LC_COLLATE], LCMAP_SORTKEY,
            _string2, -1, (wchar_t *)bbuffer, _count)))
        {
		/* buffer not big enough, get size required. */

            if (0 == (size = LCMapStringW(_lc_handle[LC_COLLATE], LCMAP_SORTKEY,
                _string2, -1, NULL, 0)))
			size = INT_MAX; /* default error */
            else
                size--; /* don't count NULL */

	} else {
            int i;
            /* string successfully mapped, convert to wide char */

            for (i = 0; i < size; i++)
                _string1[i] = (wchar_t)bbuffer[i];

            size--; /* don't count NULL */
        }
        
error_cleanup:
	_munlock (_LC_COLLATE_LOCK);
	return (size_t)size;
#endif /* _INTL */
}