/***
*mbtolwr.c - Convert character to lower case (MBCS).
*
*       Copyright (c) 1985-1997, Microsoft Corporation.  All rights reserved.
*
*Purpose:
*       Convert character to lower case (MBCS).
*
*******************************************************************************/

#ifdef _MBCS

#ifdef _WIN32
#include <awint.h>
#endif  /* _WIN32 */

#include <cruntime.h>
#include <ctype.h>
#include <mbdata.h>
#include <mbctype.h>
#include <mbstring.h>


/***
* _mbctolower - Convert character to lower case (MBCS)
*
*Purpose:
*       If the given character is upper case, convert it to lower case.
*       Handles MBCS characters correctly.
*
*       Note:  Use test against 0x00FF instead of _ISLEADBYTE
*       to ensure that we don't call SBCS routine with a two-byte
*       value.
*
*Entry:
*       unsigned int c = character to convert
*
*Exit:
*       Returns converted character
*
*Exceptions:
*
*******************************************************************************/

unsigned int __cdecl _mbctolower(
    unsigned int c
    )
{
        unsigned char val[2];
#ifdef _WIN32
        unsigned char ret[4];
#endif  /* _WIN32 */

        if (c > 0x00FF)
        {
            val[0] = (c >> 8) & 0xFF;
            val[1] = c & 0xFF;

            if (!_ismbblead(val[0]))
                return c;

#ifdef _WIN32

            if (__crtLCMapStringA(  __mblcid,
                                    LCMAP_LOWERCASE,
                                    val,
                                    2,
                                    ret,
                                    2,
                                    __mbcodepage) == 0)
                return c;

            c = ret[1];
            c += ret[0] << 8;

            return c;

#else  /* _WIN32 */

            if      (c >= _MBUPPERLOW1 && c <= _MBUPPERHIGH1)
                c += _MBCASEDIFF1;

            else if (c >= _MBUPPERLOW2 && c <= _MBUPPERHIGH2)
                c += _MBCASEDIFF2;

            return c;

#endif  /* _WIN32 */

        } else

                return (unsigned int)_mbbtolower((int)c);

}

#endif  /* _MBCS */
