//
// Windows NT WOW v5
//
// fmtmsg.c -- 16-bit FormatMessage API, lifted from Win95
//             \win\core\user\wn32rare.c by Dave Hart
//
//

#include "user.h"

typedef DWORD ULONG;

// from win95 user.h
#define CODESEG     _based(_segname("_CODE"))
#define TESTFAR(p)  SELECTOROF(p)

// from win95 dev\inc16\windows.h
#define FORMAT_MESSAGE_ALLOCATE_BUFFER  0x00000100      /* ;Internal NT */
#define FORMAT_MESSAGE_IGNORE_INSERTS   0x00000200      /* ;Internal NT */
#define FORMAT_MESSAGE_FROM_STRING      0x00000400      /* ;Internal NT */
#define FORMAT_MESSAGE_FROM_HMODULE     0x00000800      /* ;Internal NT */
#define FORMAT_MESSAGE_FROM_SYSTEM      0x00001000      /* ;Internal NT */
//#define FORMAT_MESSAGE_ARGUMENT_ARRAY   0x00002000      /* ;Internal */
#define FORMAT_MESSAGE_MAX_WIDTH_MASK   0x000000FF      /* ;Internal NT */
#define FORMAT_MESSAGE_VALID            0x00003FFF      /* ;Internal */


char CODESEG szStringFormat[] = "%s";
char CODESEG szStringFormat2[] = "%%%lu";
char CODESEG szStringFormat3[] = "%%%lu!%s!";


#if 0
// ----------------------------------------------------------------------------
//
//  GetSystemInstance()
//
//  _loadds function to return hInstanceWin.  Needed cuz FormatMessage can
//  LocalAlloc a buffer for an app.  We GlobalAlloc() a temp buffer to do the
//  actual work in.  Both local & global memory go away when the context that
//  created it terminates.
//
// ----------------------------------------------------------------------------
HINSTANCE NEAR _loadds FMGetSystemInstance(void)
{
    return(hInstanceWin);
}
#endif


#undef LocalAlloc
#undef LocalFree
extern HLOCAL WINAPI LocalAlloc(UINT, UINT);
extern HLOCAL WINAPI LocalFree(HLOCAL);

// ----------------------------------------------------------------------------
//
//  FormatMessage()
//
//  16-bit version of FormatMessage32().
//
//  Note that this API is NOT _loadds.  We might need to LocalAlloc() a buffer
//  for the result.  Therefore, we can't just use random static string vars.
//  They _must_ be CODESEG.
//
// ----------------------------------------------------------------------------
UINT _far _pascal FormatMessage(DWORD dwFlags, LPVOID lpSource, UINT idMessage,
    UINT idLanguage, LPSTR lpResult, UINT cbResultMax, DWORD FAR * rglArgs)
{
    LPSTR       lpBuffer;
    HINSTANCE   hInstance;
    UINT        Column;
    UINT        MaximumWidth;
    DWORD       rgInserts[100];
    WORD        MaxInsert, CurInsert;
    UINT        cbNeeded, cbResult;
    char        szMessage[256];
    LPSTR       MessageFormat;
    UINT        cbMessage;
    UINT        PrintParameterCount;
    DWORD       PrintParameter1;
    DWORD       PrintParameter2;
    char        PrintFormatString[32];
    LPSTR       s, s1, s1base;
    LPSTR       lpAlloc;
    LPSTR       lpDst, lpDstBeg;

    //
    // Force idLanguage to be 0 for 16-bit apps, for now...
    //
    if (idLanguage)
    {
        DebugErr(DBF_ERROR, "FormatMessage: language id must be 0");
        return(0);
    }

    //
    // Prevent NULL lpResult
    //
    if (!TESTFAR(lpResult))
    {
        DebugErr(DBF_ERROR, "FormatMessage: NULL result buffer");
        return(0);
    }

    //
    // Prevent caller from using non-defined flags...
    //
    if (dwFlags & ~FORMAT_MESSAGE_VALID)
    {
        DebugErr(DBF_ERROR, "FormatMessage: invalid flags");
        return(0);
    }

    //
    // Get temporary buffer.
    //
    if (dwFlags & FORMAT_MESSAGE_ALLOCATE_BUFFER)
        cbResultMax = 0x7FFE;

    lpBuffer = MAKELP(GlobalAlloc(GHND, (DWORD)cbResultMax+1), 0);
    if (!SELECTOROF(lpBuffer))
    {
        DebugErr(DBF_ERROR, "FormatMessage:  Couldn't allocate enough memory");
        return(0);
    }

    lpAlloc = NULL;
    cbResult = 0;

    MaximumWidth = LOWORD(dwFlags & FORMAT_MESSAGE_MAX_WIDTH_MASK);

    //
    // Get message string
    //
    if (dwFlags & FORMAT_MESSAGE_FROM_STRING)
    {
        if (!TESTFAR(lpSource))
        {
            DebugErr(DBF_ERROR, "FormatMessage:  NULL format string");
            goto FailureExit;
        }

        MessageFormat = lpSource;
        cbMessage = lstrlen(MessageFormat);
    }
    else
    {
        if (dwFlags & FORMAT_MESSAGE_FROM_HMODULE)
        {
            hInstance = (HINSTANCE)OFFSETOF(lpSource);
            if (!hInstance)
            {
                DebugErr(DBF_ERROR, "FormatMessage:  NULL hInstance not allowed for 16 bits");
                goto FailureExit;
            }
        }
        else if (dwFlags & FORMAT_MESSAGE_FROM_SYSTEM)
#if 0
            // This doesn't work on WOW and it's not worth
            // fixing because our user.exe doesn't have any
            // FormatMessage text as string resources.
            hInstance = FMGetSystemInstance();
#else
        {
            DebugErr(DBF_ERROR, "FormatMessage:  FORMAT_MESSAGE_FROM_SYSTEM");
            goto FailureExit;
        }
#endif
        else
        {
            DebugErr(DBF_ERROR, "FormatMessage:  Invalid source");
            goto FailureExit;
        }

        //
        // Load the string
        //
        cbMessage = LoadString(hInstance, idMessage, szMessage,
            sizeof(szMessage)-1);

        if (!cbMessage)
        {
            DebugErr(DBF_ERROR, "FormatMessage:  Couldn't load source string");
            goto FailureExit;
        }

        MessageFormat = (LPSTR)szMessage;
    }

    lpDst = lpBuffer;
    MaxInsert = 0;
    Column = 0;
    s = MessageFormat;

    while (*s)
    {
        if (*s == '%')
        {
            s++;

            lpDstBeg = lpDst;
            if (*s >= '1' && *s <= '9')
            {
                CurInsert = *s++ - '0';
                if (*s >= '0' && *s <= '9')
                {
                    CurInsert = (CurInsert * 10) + (*s++ - '0');
                }
                CurInsert--;

                PrintParameterCount = 0;
                if (*s == '!')
                {
                    s1 = s1base = PrintFormatString;
                    *s1++ = '%';
                    s++;
                    while (*s != '!')
                    {
                        if (*s != '\0')
                        {
                            if (s1 >= (s1base + sizeof(PrintFormatString) - 1))
                            {
                                goto ParamError;
                            }

                            if (*s == '*')
                            {
                                if (PrintParameterCount++ > 1)
                                {
                                    goto ParamError;
                                }
                            }

                            *s1++ = *s++;
                        }
                        else
                        {
ParamError: 
                            DebugErr(DBF_ERROR, "FormatMessage:  Invalid format string");
                            goto FailureExit;
                        }
                    }

                    s++;
                    *s1 = '\0';
                }
                else
                {
                    lstrcpy(PrintFormatString, szStringFormat);
                    s1 = PrintFormatString + lstrlen(PrintFormatString);
                }

                if (!(dwFlags & FORMAT_MESSAGE_IGNORE_INSERTS) && TESTFAR(rglArgs))
                {
                    while (CurInsert >= MaxInsert)
                    {
                        rgInserts[MaxInsert++] = *(rglArgs++);
                    }

                    s1 = (LPSTR)rgInserts[CurInsert];
                    PrintParameter1 = 0;
                    PrintParameter2 = 0;
                    if (PrintParameterCount > 0)
                    {
                        PrintParameter1 = rgInserts[MaxInsert++] = *(rglArgs++);
                        if (PrintParameterCount > 1)
                        {
                            PrintParameter2 = rgInserts[MaxInsert++] = *(rglArgs++);
                        }
                    }

                    lpDst += wsprintf(lpDst, PrintFormatString, s1,
                        PrintParameter1, PrintParameter2);
                }
                else if (!lstrcmp(PrintFormatString, szStringFormat))
                {
                    lpDst += wsprintf(lpDst, szStringFormat2, CurInsert+1);
                }
                else
                {
                    lpDst += wsprintf(lpDst, szStringFormat3, CurInsert+1,
                        (LPSTR)&PrintFormatString[1]);
                }
            }
            else if (*s == '0')
                break;
            else if (!*s)
                goto FailureExit;
            else if (*s == '!')
            {
                *lpDst++ = '!';
                s++;
            }
            else if (*s == 't')
            {
                *lpDst++ = '\t';
                s++;
                if (Column % 8)
                {
                    Column = (Column + 7) & ~7;
                }
                else
                {
                    Column += 8;
                }
            }
            else if (*s == 'b')
            {
                *lpDst++ = ' ';
                s++;
            }
            else if (*s == 'r')
            {
                *lpDst++ = '\r';
                s++;
                lpDstBeg = NULL;
            }
            else if (*s == '\n')
            {
                *lpDst++ = '\r';
                *lpDst++ = '\n';
                s++;
                lpDstBeg = NULL;
            }
            else
            {
                if (dwFlags & FORMAT_MESSAGE_IGNORE_INSERTS)
                {
                    *lpDst++ = '%';
                }

                *lpDst++ = *s++;
            }

            if (!TESTFAR(lpDstBeg))
            {
                Column = 0;
            }
            else
            {
                Column += lpDst - lpDstBeg;
            }
        }
        else
        {
            char c;

            c = *s++;
            if (c == '\r')
            {
                if (*s == '\n')
                {
                    s++;
                }

                if (MaximumWidth)
                {
                    c = ' ';
                }
                else
                {
                    c = '\n';
                }
            }

            if (c == '\n' || (c == ' ' && MaximumWidth &&
                MaximumWidth != FORMAT_MESSAGE_MAX_WIDTH_MASK &&
                Column >= MaximumWidth))
            {

                *lpDst++ = '\r';
                *lpDst++ = '\n';
                Column = 0;
            }
            else
            {
                *lpDst++ = c;
                Column++;
            }
        }
    }

    *lpDst++ = 0;
    cbNeeded = lpDst - lpBuffer;

    if (dwFlags & FORMAT_MESSAGE_ALLOCATE_BUFFER)
    {
        PSTR pstr;

        *(PSTR FAR *)lpResult = NULL;

        pstr = (PSTR)LocalAlloc(LPTR, cbNeeded);

        if (!pstr)
        {
            DebugErr(DBF_ERROR, "FormatMessge:  couldn't LocalAlloc memory for result");
            goto FailureExit;
        }

        lpDst = lpAlloc = (LPSTR)pstr;
    }
    else if (cbNeeded > cbResultMax)
    {
        DebugErr(DBF_ERROR, "FormatMessage:  passed in buffer is too small for result");
        goto FailureExit;
    }
    else
    {
        lpDst = lpResult;
    }

    lstrcpyn(lpDst, lpBuffer, cbNeeded);

    cbResult = --cbNeeded;

FailureExit:
    if (TESTFAR(lpAlloc))
    {
        if (cbResult)
        {
            *(PSTR FAR *)lpResult = (PSTR)OFFSETOF(lpAlloc);
        }
        else
        {
            LocalFree((HANDLE)OFFSETOF(lpAlloc));
        }
    }

    if (TESTFAR(lpBuffer))
        GlobalFree((HANDLE)SELECTOROF(lpBuffer));

    return(cbResult);
}