/***
*a_map.c - A version of LCMapString.
*
*       Copyright (c) 1993-2001, Microsoft Corporation.  All rights reserved.
*
*Purpose:
*       Use either LCMapStringA or LCMapStringW depending on which is available
*
*Revision History:
*       09-14-93  CFW   Module created.
*       09-17-93  CFW   Use unsigned chars.
*       09-23-93  CFW   Correct NLS API params and comments about same.
*       10-07-93  CFW   Optimize WideCharToMultiByte, use NULL default char.
*       10-22-93  CFW   Test for invalid MB chars using global preset flag.
*       11-09-93  CFW   Allow user to pass in code page.
*       11-18-93  CFW   Test for entry point function stubs.
*       02-23-94  CFW   Use W flavor whenever possible.
*       03-31-94  CFW   Include awint.h.
*       07-26-94  CFW   Bug fix #14730, LCMapString goes past NULLs.
*       12-21-94  CFW   Remove invalid MB chars NT 3.1 hack.
*       12-27-94  CFW   Call direct, all OS's have stubs.
*       01-10-95  CFW   Debug CRT allocs.
*       02-15-97  RDK   For narrow mapping, try W version first so Windows NT
*                       can process nonANSI codepage correctly.
*       03-16-97  RDK   Added error flag to __crtLCMapStringA.
*       05-09-97  GJF   Renamed and moved __crtLCMapStringW into a separate 
*                       file. Revised to use _alloca instead of malloc. Also,
*                       reformatted.
*       05-27-98  GJF   Changed strncnt() so that it will never examine the
*                       (cnt + 1)-th byte of the string.
*       08-18-98  GJF   Use _malloc_crt if _alloca fails.
*       04-28-99  GJF   Changed dwFlags arg value to 0 in WideCharToMultiByte
*                       calls to avoid problems with codepage 1258 on NT 5.0.
*       12-10-99  GB    Added support for recovery from stack overflow around 
*                       _alloca().
*       05-17-00  GB    Use ERROR_CALL_NOT_IMPLEMENTED for existance of W API
*       08-23-00  GB    Fixed bug with non Ansi CP on Win9x.
*       07-07-01  BWT   Fix error path (set ret=FALSE before branching, not after)
*
*******************************************************************************/

#include <cruntime.h>
#include <internal.h>
#include <stdlib.h>
#include <setlocal.h>
#include <locale.h>
#include <awint.h>
#include <dbgint.h>
#include <malloc.h>

#define USE_W   1
#define USE_A   2

/***
*int __cdecl strncnt - count characters in a string, up to n.
*
*Purpose:
*       Internal local support function. Counts characters in string before
*       null. If null is not found in n chars, then return n.
*
*Entry:
*       const char *string   - start of string
*       int n                - byte count
*
*Exit:
*       returns number of bytes from start of string to
*       null (exclusive), up to n.
*
*Exceptions:
*
*******************************************************************************/

static int __cdecl strncnt (
        const char *string,
        int cnt
        )
{
        int n = cnt;
        char *cp = (char *)string;

        while (n-- && *cp)
            cp++;

        return cnt - n - 1;
}


/***
*int __cdecl __crtLCMapStringA - Get type information about an ANSI string.
*
*Purpose:
*       Internal support function. Assumes info in ANSI string format. Tries
*       to use NLS API call LCMapStringA if available and uses LCMapStringW
*       if it must. If neither are available it fails and returns 0.
*
*Entry:
*       LCID     Locale      - locale context for the comparison.
*       DWORD    dwMapFlags  - see NT\Chicago docs
*       LPCSTR   lpSrcStr    - pointer to string to be mapped
*       int      cchSrc      - wide char (word) count of input string 
*                              (including NULL if any)
*                              (-1 if NULL terminated) 
*       LPSTR    lpDestStr   - pointer to memory to store mapping
*       int      cchDest     - char (byte) count of buffer (including NULL)
*       int      code_page   - for MB/WC conversion. If 0, use __lc_codepage
*       BOOL     bError      - TRUE if MB_ERR_INVALID_CHARS set on call to
*                              MultiByteToWideChar when GetStringTypeW used.
*
*Exit:
*       Success: number of chars written to lpDestStr (including NULL)
*       Failure: 0
*
*Exceptions:
*
*******************************************************************************/

int __cdecl __crtLCMapStringA(
        LCID     Locale,
        DWORD    dwMapFlags,
        LPCSTR   lpSrcStr,
        int      cchSrc,
        LPSTR    lpDestStr,
        int      cchDest,
        int      code_page,
        BOOL     bError
        )
{
        static int f_use = 0;

        /* 
         * Look for unstubbed 'preferred' flavor. Otherwise use available flavor.
         * Must actually call the function to ensure it's not a stub.
         * (Always try wide version first so WinNT can process codepage correctly.)
         */
    
        if (0 == f_use) {
            if (0 != LCMapStringW(0, LCMAP_LOWERCASE, L"\0", 1, NULL, 0))
                f_use = USE_W;
            else if (GetLastError() == ERROR_CALL_NOT_IMPLEMENTED)
                f_use = USE_A;
        }

        /*
         * LCMapString will map past NULL. Must find NULL if in string
         * before cchSrc characters.
         */
        if (cchSrc > 0)
            cchSrc = strncnt(lpSrcStr, cchSrc);

        /* Use "A" version */

        if (USE_A == f_use || f_use == 0) {
            char *cbuffer = NULL;
            char *cbuffer1 = NULL;
            int ret;
            int malloc_flag1 = 0;
            int AnsiCP;
            int buff_size;

            if (0 == Locale)
                Locale = __lc_handle[LC_CTYPE];
            if (0 == code_page)
                code_page = __lc_codepage;

            if ( -1 == (AnsiCP = __ansicp(Locale)))
                return FALSE;
            /* LCMapStringA uses ANSI code page to map the string. Check if
             * codepage is ansi, if not convert the input string to ansi 
             * codepage then map to a temporary string and then convert temp
             * string to DestStr.
             */
            if ( AnsiCP != code_page)
            {
                cbuffer = __convertcp(code_page, AnsiCP, lpSrcStr, &cchSrc, NULL, 0);
                if (cbuffer == NULL)
                    return FALSE;
                lpSrcStr = cbuffer;
                if (0 == (buff_size = LCMapStringA( Locale,
                                                    dwMapFlags,
                                                    lpSrcStr,
                                                    cchSrc,
                                                    0,
                                                    0 )))
                {
                    ret = FALSE;
                    goto cleanupA;
                }
                __try{
                    cbuffer1 = (char *)_alloca(sizeof(char) * buff_size);
                    memset(cbuffer1, 0, sizeof(char) * buff_size);
                } __except (EXCEPTION_EXECUTE_HANDLER) {
                    _resetstkoflw();
                    cbuffer1 = NULL;
                }
                
                if ( cbuffer1 == NULL ) {
                    if ( (cbuffer1 = (char *)_malloc_crt(sizeof(char) * buff_size)) == NULL)
                    {
                        ret = FALSE;
                        goto cleanupA;
                    }
                    (void)memset( cbuffer1, 0, sizeof(char) * buff_size);
                    malloc_flag1++;
                }
                if (0 == (buff_size = LCMapStringA( Locale, 
                                                    dwMapFlags,
                                                    lpSrcStr,
                                                    cchSrc,
                                                    cbuffer1,
                                                    buff_size)))
                {
                    ret = FALSE;
                } else {
                    if ( NULL == __convertcp(AnsiCP, 
                                             code_page,
                                             cbuffer1,
                                             &buff_size,
                                             lpDestStr,
                                             cchDest))
                        ret = FALSE;
                    else 
                        ret = TRUE;
                }
cleanupA:
                if(malloc_flag1)
                    _free_crt(cbuffer1);
            } else
            {
                ret = LCMapStringA( Locale, dwMapFlags, lpSrcStr, cchSrc, 
                                    lpDestStr, cchDest );
            }
            if ( cbuffer != NULL)
                _free_crt(cbuffer);
            return ret;
        }

        /* Use "W" version */

        if (USE_W == f_use) 
        {
            int retval = 0;
            int inbuff_size;
            int outbuff_size;
            wchar_t *inwbuffer;
            wchar_t *outwbuffer;
            int malloc_flag1 = 0;
            int malloc_flag2 = 0;

            /*
             * Convert string and return the requested information. Note that 
             * we are converting to a wide string so there is not a 
             * one-to-one correspondence between number of wide chars in the 
             * input string and the number of *bytes* in the buffer. However, 
             * there had *better be* a one-to-one correspondence between the 
             * number of wide characters and the number of multibyte characters 
             * or the resulting mapped string will be worthless to the user.
             */

            /*
             * Use __lc_codepage for conversion if code_page not specified
             */

            if (0 == code_page)
                code_page = __lc_codepage;

            /* find out how big a buffer we need (includes NULL if any) */
            if ( 0 == (inbuff_size = 
                       MultiByteToWideChar( code_page,
                                            bError ? MB_PRECOMPOSED | 
                                                MB_ERR_INVALID_CHARS : 
                                                MB_PRECOMPOSED,
                                            lpSrcStr, 
                                            cchSrc, 
                                            NULL, 
                                            0 )) )
                return 0;

            /* allocate enough space for wide chars */
            __try {
                inwbuffer = (wchar_t *)_alloca( inbuff_size * sizeof(wchar_t) );
            }
            __except(EXCEPTION_EXECUTE_HANDLER) {
                _resetstkoflw();
                inwbuffer = NULL;
            }

            if ( inwbuffer == NULL ) {
                if ( (inwbuffer = (wchar_t *)_malloc_crt(inbuff_size * sizeof(wchar_t)))
                    == NULL )
                    return 0;
                malloc_flag1++;
            }

            /* do the conversion */
            if ( 0 == MultiByteToWideChar( code_page, 
                                           MB_PRECOMPOSED, 
                                           lpSrcStr, 
                                           cchSrc, 
                                           inwbuffer, 
                                           inbuff_size) )
                goto error_cleanup;

            /* get size required for string mapping */
            if ( 0 == (retval = LCMapStringW( Locale, 
                                              dwMapFlags,
                                              inwbuffer, 
                                              inbuff_size, 
                                              NULL, 
                                              0 )) )
                goto error_cleanup;

            if (dwMapFlags & LCMAP_SORTKEY) {
                /* retval is size in BYTES */

                if (0 != cchDest) {

                    if (retval > cchDest)
                        goto error_cleanup;

                    /* do string mapping */
                    if ( 0 == LCMapStringW( Locale, 
                                            dwMapFlags, 
                                            inwbuffer, 
                                            inbuff_size, 
                                            (LPWSTR)lpDestStr, 
                                            cchDest ) )
                        goto error_cleanup;
                }
            }
            else {
                /* retval is size in wide chars */

                outbuff_size = retval;

                /* allocate enough space for wide chars (includes NULL if any) */
                __try {
                    outwbuffer = (wchar_t *)_alloca( outbuff_size * sizeof(wchar_t) );
                }
                __except(EXCEPTION_EXECUTE_HANDLER) {
                    _resetstkoflw();
                    outwbuffer = NULL;
                }

                if ( outwbuffer == NULL ) {
                    if ( (outwbuffer = (wchar_t *)_malloc_crt(outbuff_size * sizeof(wchar_t)))
                        == NULL )
                        goto error_cleanup;
                    malloc_flag2++;
                }

                /* do string mapping */
                if ( 0 == LCMapStringW( Locale, 
                                        dwMapFlags, 
                                        inwbuffer, 
                                        inbuff_size, 
                                        outwbuffer, 
                                        outbuff_size ) )
                    goto error_cleanup;

                if (0 == cchDest) {
                    /* get size required */
                    if ( 0 == (retval = 
                               WideCharToMultiByte( code_page, 
                                                    0,
                                                    outwbuffer, 
                                                    outbuff_size, 
                                                    NULL, 
                                                    0, 
                                                    NULL, 
                                                    NULL )) )
                        goto error_cleanup;
                } 
                else {
                    /* convert mapping */
                    if ( 0 == (retval = 
                               WideCharToMultiByte( code_page, 
                                                    0,
                                                    outwbuffer, 
                                                    outbuff_size, 
                                                    lpDestStr, 
                                                    cchDest, 
                                                    NULL, 
                                                    NULL )) )
                        goto error_cleanup;
                }
            }

error_cleanup:
            if ( malloc_flag2 )
                _free_crt(outwbuffer);

            if ( malloc_flag1 )
                _free_crt(inwbuffer);

            return retval;
        }
        else   /* f_use is neither USE_A nor USE_W */
            return 0;
}