//--------------------------------------------------------------------------------------
// File: DXUTUniBuffer.cpp
//
// Desc: CUniBuffer, the Uniscribe-backed text buffer behind the edit controls
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//--------------------------------------------------------------------------------------
#include "dxstdafx.h"
// <new.h> omits operator delete's throw(), which forces unwind frames into
// every dtor that deletes
#include <new>
#include "DXUTgui.h"

#define UNISCRIBE_DLLNAME "\\usp10.dll"

#define GETPROCADDRESS( Module, APIName, Temp ) \
    Temp = GetProcAddress( Module, #APIName ); \
    if( Temp ) \
        *(FARPROC*)&_##APIName = Temp

#define PLACEHOLDERPROC( APIName ) \
    _##APIName = Dummy_##APIName


// DXUT_MAX_EDITBOXLENGTH is the maximum string length allowed in edit boxes,
// including the NULL terminator.
// 
// Uniscribe does not support strings having bigger-than-16-bits length.
// This means that the string must be less than 65536 characters long,
// including the NULL terminator.
#define DXUT_MAX_EDITBOXLENGTH 0xFFFF

// stays in DXUTgui.cpp; retail reaches it across the tu boundary
LPCWSTR MaskText( LPCWSTR wszText );


// Static member initialization
HINSTANCE CUniBuffer::s_hDll = NULL;
HRESULT (WINAPI *CUniBuffer::_ScriptApplyDigitSubstitution)( const SCRIPT_DIGITSUBSTITUTE*, SCRIPT_CONTROL*, SCRIPT_STATE* ) = Dummy_ScriptApplyDigitSubstitution;
HRESULT (WINAPI *CUniBuffer::_ScriptStringAnalyse)( HDC, const void *, int, int, int, DWORD, int, SCRIPT_CONTROL*, SCRIPT_STATE*, const int*, SCRIPT_TABDEF*, const BYTE*, SCRIPT_STRING_ANALYSIS* ) = Dummy_ScriptStringAnalyse;
HRESULT (WINAPI *CUniBuffer::_ScriptStringCPtoX)( SCRIPT_STRING_ANALYSIS, int, BOOL, int* ) = Dummy_ScriptStringCPtoX;
HRESULT (WINAPI *CUniBuffer::_ScriptStringXtoCP)( SCRIPT_STRING_ANALYSIS, int, int*, int* ) = Dummy_ScriptStringXtoCP;
HRESULT (WINAPI *CUniBuffer::_ScriptStringFree)( SCRIPT_STRING_ANALYSIS* ) = Dummy_ScriptStringFree;
const SCRIPT_LOGATTR* (WINAPI *CUniBuffer::_ScriptString_pLogAttr)( SCRIPT_STRING_ANALYSIS ) = Dummy_ScriptString_pLogAttr;
const int* (WINAPI *CUniBuffer::_ScriptString_pcOutChars)( SCRIPT_STRING_ANALYSIS ) = Dummy_ScriptString_pcOutChars;


//--------------------------------------------------------------------------------------
void CUniBuffer::Initialize()
{
    if( s_hDll ) // Only need to do once
        return;

    TCHAR wszPath[MAX_PATH+1];
    if( !::GetSystemDirectory( wszPath, MAX_PATH+1 ) )
        return;

    // Verify whether it is safe to concatenate these strings
    int len1 = lstrlen(wszPath);
    int len2 = lstrlen(UNISCRIBE_DLLNAME);
    if (len1 + len2 > MAX_PATH)
    {
        return;
    }

    // We have verified that the concatenated string will fit into wszPath,
    // so it is safe to concatenate them.
    StringCchCat( wszPath, MAX_PATH, UNISCRIBE_DLLNAME );

    s_hDll = LoadLibrary( wszPath );
    if( s_hDll )
    {
        FARPROC Temp;
        GETPROCADDRESS( s_hDll, ScriptApplyDigitSubstitution, Temp );
        GETPROCADDRESS( s_hDll, ScriptStringAnalyse, Temp );
        GETPROCADDRESS( s_hDll, ScriptStringCPtoX, Temp );
        GETPROCADDRESS( s_hDll, ScriptStringXtoCP, Temp );
        GETPROCADDRESS( s_hDll, ScriptStringFree, Temp );
        GETPROCADDRESS( s_hDll, ScriptString_pLogAttr, Temp );
        GETPROCADDRESS( s_hDll, ScriptString_pcOutChars, Temp );
    }
}


//--------------------------------------------------------------------------------------
void CUniBuffer::Uninitialize()
{
    if( s_hDll )
    {
        PLACEHOLDERPROC( ScriptApplyDigitSubstitution );
        PLACEHOLDERPROC( ScriptStringAnalyse );
        PLACEHOLDERPROC( ScriptStringCPtoX );
        PLACEHOLDERPROC( ScriptStringXtoCP );
        PLACEHOLDERPROC( ScriptStringFree );
        PLACEHOLDERPROC( ScriptString_pLogAttr );
        PLACEHOLDERPROC( ScriptString_pcOutChars );

        FreeLibrary( s_hDll );
        s_hDll = NULL;
    }
}


//--------------------------------------------------------------------------------------
bool CUniBuffer::SetBufferSize( int nNewSize )
{
    // If the current size is already the maximum allowed,
    // we can't possibly allocate more.
    if( m_nBufferSize == DXUT_MAX_EDITBOXLENGTH )
        return false;

    int nAllocateSize = ( nNewSize == -1 || nNewSize < m_nBufferSize * 2 ) ? ( m_nBufferSize ? m_nBufferSize * 2 : 256 ) : nNewSize * 2;

    // Cap the buffer size at the maximum allowed.
    if( nAllocateSize > DXUT_MAX_EDITBOXLENGTH )
        nAllocateSize = DXUT_MAX_EDITBOXLENGTH;

    WCHAR *pTempBuffer = new WCHAR[nAllocateSize];
    if( !pTempBuffer )
        return false;
    if( m_pwszBuffer )
    {
        CopyMemory( pTempBuffer, m_pwszBuffer, m_nBufferSize * sizeof(WCHAR) );
        delete[] m_pwszBuffer;
    }
    else
    {
        ZeroMemory( pTempBuffer, sizeof(WCHAR) * nAllocateSize );
    }

    m_pwszBuffer = pTempBuffer;
    m_nBufferSize = nAllocateSize;
    return true;
}


//--------------------------------------------------------------------------------------
// Uniscribe -- Analyse() analyses the string in the buffer
//--------------------------------------------------------------------------------------
HRESULT CUniBuffer::Analyse()
{
    if( m_Analysis )
        _ScriptStringFree( &m_Analysis );

    SCRIPT_CONTROL ScriptControl; // For uniscribe
    SCRIPT_STATE   ScriptState;   // For uniscribe
    ZeroMemory( &ScriptControl, sizeof(ScriptControl) );
    ZeroMemory( &ScriptState, sizeof(ScriptState) );
    _ScriptApplyDigitSubstitution ( NULL, &ScriptControl, &ScriptState );

    if( !m_pFontNode )
        return E_FAIL;

	HRESULT hr;
	if( !field_12 )
	{
        hr = _ScriptStringAnalyse( m_pFontNode->pFont ? m_pFontNode->pFont->GetDC() : NULL,
                                       m_pwszBuffer,
                                       lstrlenW( m_pwszBuffer ) + 1,  // NULL is also analyzed.
                                       lstrlenW( m_pwszBuffer ) * 3 / 2 + 16,
                                       -1,
                                       SSA_BREAK | SSA_GLYPHS | SSA_FALLBACK | SSA_LINK,
                                       0,
                                       &ScriptControl,
                                       &ScriptState,
                                       NULL,
                                       NULL,
                                       NULL,
                                       &m_Analysis );
	}
	else
	{
        hr = _ScriptStringAnalyse( m_pFontNode->pFont ? m_pFontNode->pFont->GetDC() : NULL,
                                       MaskText( m_pwszBuffer ),
                                       lstrlenW( MaskText( m_pwszBuffer ) ) + 1,  // NULL is also analyzed.
                                       lstrlenW( MaskText( m_pwszBuffer ) ) * 3 / 2 + 16,
                                       -1,
                                       SSA_BREAK | SSA_GLYPHS | SSA_FALLBACK | SSA_LINK,
                                       0,
                                       &ScriptControl,
                                       &ScriptState,
                                       NULL,
                                       NULL,
                                       NULL,
                                       &m_Analysis );
	}
    if( SUCCEEDED( hr ) )
        m_bAnalyseRequired = false;  // Analysis is up-to-date
    return hr;
}


//--------------------------------------------------------------------------------------
CUniBuffer::CUniBuffer( int nInitialSize )
{
    CUniBuffer::Initialize();  // ensure static vars are properly init'ed first

    m_nBufferSize = 0;
    m_pwszBuffer = NULL;
    m_bAnalyseRequired = true;
    m_Analysis = NULL;
    m_pFontNode = NULL;
    field_8 = 0;
	field_12 = 0;

    if( nInitialSize > 0 )
        SetBufferSize( nInitialSize );
}


//--------------------------------------------------------------------------------------
CUniBuffer::~CUniBuffer()
{
    delete[] m_pwszBuffer;
    if( m_Analysis )
        _ScriptStringFree( &m_Analysis );
}


//--------------------------------------------------------------------------------------
WCHAR& CUniBuffer::operator[]( int n )  // No param checking
{
    // This version of operator[] is called only
    // if we are asking for write access, so
    // re-analysis is required.
    m_bAnalyseRequired = true;
    return m_pwszBuffer[n];
}


//--------------------------------------------------------------------------------------
void CUniBuffer::Clear()
{
    *m_pwszBuffer = L'\0';
    m_bAnalyseRequired = true;
}


//--------------------------------------------------------------------------------------
// Inserts the char at specified index.
// If nIndex == -1, insert to the end.
//--------------------------------------------------------------------------------------
bool CUniBuffer::InsertChar( int nIndex, WCHAR tchr )
{
    assert( nIndex >= 0 );

    if( nIndex < 0 || nIndex > lstrlenW( m_pwszBuffer ) )
        return false;  // invalid index

    // Check for maximum length allowed
    if( GetTextSize() + 1 >= DXUT_MAX_EDITBOXLENGTH )
        return false;

    if( lstrlenW( m_pwszBuffer ) + 1 >= m_nBufferSize )
    {
        if( !SetBufferSize( -1 ) )
            return false;  // out of memory
    }

    assert( m_nBufferSize >= 2 );

    // Shift the characters after the index, start by copying the null terminator
    WCHAR* dest = m_pwszBuffer + lstrlenW(m_pwszBuffer)+1;
    WCHAR* stop = m_pwszBuffer + nIndex;
    WCHAR* src = dest - 1;

    while( dest > stop )
    {
        *dest-- = *src--;
    }

    // Set new character
    m_pwszBuffer[ nIndex ] = tchr;
    m_bAnalyseRequired = true;

    return true;
}

bool CUniBuffer::InsertChar(int nIndex, CHAR tchr)
{
	WCHAR WideCharStr[2];
	ZeroMemory(&WideCharStr[0], sizeof(WideCharStr));

	if(field_8)
	{
		CHAR MultiByteStr[3];
		MultiByteStr[0] = field_8;
		MultiByteStr[1] = tchr;
		MultiByteStr[2] = 0;
		MultiByteToWideChar(CP_ACP, 0, MultiByteStr, 2, WideCharStr, 1);
		InsertChar(nIndex, WideCharStr[0]);
		field_8 = 0;
		return true;
	}
	else if(IsDBCSLeadByteEx(CP_ACP, tchr))
	{
		field_8 = tchr;
		return false;
	}
	else
	{
		MultiByteToWideChar(CP_ACP, 0, &tchr, 1, WideCharStr, 1);
		InsertChar(nIndex, WideCharStr[0]);
		return true;
	}
}

// overwrite variant of InsertChar; the buffer index assignment is samp's, not a typo of ours
bool CUniBuffer::SetChar(int nIndex, CHAR tchr)
{
	WCHAR WideCharStr[2];
	ZeroMemory(&WideCharStr[0], sizeof(WideCharStr));

	if(field_8)
	{
		CHAR MultiByteStr[3];
		MultiByteStr[0] = field_8;
		MultiByteStr[1] = tchr;
		MultiByteStr[2] = 0;
		MultiByteToWideChar(CP_ACP, 0, MultiByteStr, 2, WideCharStr, 1);
		InsertChar(nIndex, WideCharStr[0]);
		field_8 = 0;
		return true;
	}
	else if(IsDBCSLeadByteEx(CP_ACP, tchr))
	{
		field_8 = tchr;
		return false;
	}
	else
	{
		MultiByteToWideChar(CP_ACP, 0, &tchr, 1, WideCharStr, 1);
		this[nIndex] = WideCharStr[0];
		return true;
	}
}


//--------------------------------------------------------------------------------------
// Removes the char at specified index.
// If nIndex == -1, remove the last char.
//--------------------------------------------------------------------------------------
bool CUniBuffer::RemoveChar( int nIndex )
{
    if( !lstrlenW( m_pwszBuffer ) || nIndex < 0 || nIndex >= lstrlenW( m_pwszBuffer ) )
        return false;  // Invalid index

    MoveMemory( m_pwszBuffer + nIndex, m_pwszBuffer + nIndex + 1, sizeof(WCHAR) * ( lstrlenW( m_pwszBuffer ) - nIndex ) );
    m_bAnalyseRequired = true;
    return true;
}


//--------------------------------------------------------------------------------------
// Inserts the first nCount characters of the string pStr at specified index.
// If nCount == -1, the entire string is inserted.
// If nIndex == -1, insert to the end.
//--------------------------------------------------------------------------------------
bool CUniBuffer::InsertString( int nIndex, const WCHAR *pStr, int nCount )
{
    assert( nIndex >= 0 );

    if( nIndex > lstrlenW( m_pwszBuffer ) )
        return false;  // invalid index

    if( -1 == nCount )
        nCount = lstrlenW( pStr );

    // Check for maximum length allowed
    if( GetTextSize() + nCount >= DXUT_MAX_EDITBOXLENGTH )
        return false;

    if( lstrlenW( m_pwszBuffer ) + nCount >= m_nBufferSize )
    {
        if( !SetBufferSize( lstrlenW( m_pwszBuffer ) + nCount + 1 ) )
            return false;  // out of memory
    }

    MoveMemory( m_pwszBuffer + nIndex + nCount, m_pwszBuffer + nIndex, sizeof(WCHAR) * ( lstrlenW( m_pwszBuffer ) - nIndex + 1 ) );
    CopyMemory( m_pwszBuffer + nIndex, pStr, nCount * sizeof(WCHAR) );
    m_bAnalyseRequired = true;

    return true;
}


//--------------------------------------------------------------------------------------
bool CUniBuffer::SetText( LPCWSTR wszText )
{
    assert( wszText != NULL );

    int nRequired = int(lstrlenW( wszText ) + 1);

    // Check for maximum length allowed
    if( nRequired >= DXUT_MAX_EDITBOXLENGTH )
        return false;

    while( GetBufferSize() < nRequired )
        if( !SetBufferSize( -1 ) )
            break;
    // Check again in case out of memory occurred inside while loop.
    if( GetBufferSize() >= nRequired )
    {
        StringCchCopyW( m_pwszBuffer, GetBufferSize(), wszText );
        m_bAnalyseRequired = true;
        return true;
    }
    else
        return false;
}


//--------------------------------------------------------------------------------------
void ConvertAnsiToWide(LPCSTR wszSrc, LPWSTR wszDest, int nSize)
{
	memset(wszDest, 0, sizeof(WCHAR) * nSize);

	int nCount = MultiByteToWideChar(CP_ACP, 0, wszSrc, strlen(wszSrc), NULL, 0);
	if(nCount < nSize)
		MultiByteToWideChar(CP_ACP, 0, wszSrc, strlen(wszSrc), wszDest, nCount);
}


//--------------------------------------------------------------------------------------
bool CUniBuffer::SetText( LPCTSTR wszText )
{
	if(lstrlenA(wszText) > 1024) return false;

	WCHAR szBuffer[2049];
	ConvertAnsiToWide(wszText, szBuffer, 2048);
    SetText(szBuffer);
	return true;
}


//--------------------------------------------------------------------------------------
HRESULT CUniBuffer::CPtoX( int nCP, BOOL bTrail, int *pX )
{
    assert( pX );
    *pX = 0;  // Default

    HRESULT hr = S_OK;
    if( m_bAnalyseRequired )
        hr = Analyse();

    if( SUCCEEDED( hr ) )
        hr = _ScriptStringCPtoX( m_Analysis, nCP, bTrail, pX );

    return hr;
}


//--------------------------------------------------------------------------------------
HRESULT CUniBuffer::XtoCP( int nX, int *pCP, int *pnTrail )
{
    assert( pCP && pnTrail );
    *pCP = 0; *pnTrail = FALSE;  // Default

    HRESULT hr = S_OK;
    if( m_bAnalyseRequired )
        hr = Analyse();

    if( SUCCEEDED( hr ) )
        hr = _ScriptStringXtoCP( m_Analysis, nX, pCP, pnTrail );

    // If the coordinate falls outside the text region, we
    // can get character positions that don't exist.  We must
    // filter them here and convert them to those that do exist.
    if( *pCP == -1 && *pnTrail == TRUE )
    {
        *pCP = 0; *pnTrail = FALSE;
    } else
    if( *pCP > lstrlenW( m_pwszBuffer ) && *pnTrail == FALSE )
    {
        *pCP = lstrlenW( m_pwszBuffer ); *pnTrail = TRUE;
    }

    return hr;
}


//--------------------------------------------------------------------------------------
void CUniBuffer::GetPriorItemPos( int nCP, int *pPrior )
{
    *pPrior = nCP;  // Default is the char itself

    if( m_bAnalyseRequired )
        if( FAILED( Analyse() ) )
            return;

    const SCRIPT_LOGATTR *pLogAttr = _ScriptString_pLogAttr( m_Analysis );
    if( !pLogAttr )
        return;

    if( !_ScriptString_pcOutChars( m_Analysis ) )
        return;
    int nInitial = *_ScriptString_pcOutChars( m_Analysis );
    if( nCP - 1 < nInitial )
        nInitial = nCP - 1;
    for( int i = nInitial; i > 0; --i )
        if( pLogAttr[i].fWordStop ||       // Either the fWordStop flag is set
            ( !pLogAttr[i].fWhiteSpace &&  // Or the previous char is whitespace but this isn't.
                pLogAttr[i-1].fWhiteSpace ) )
        {
            *pPrior = i;
            return;
        }
    // We have reached index 0.  0 is always a break point, so simply return it.
    *pPrior = 0;
}
    

//--------------------------------------------------------------------------------------
void CUniBuffer::GetNextItemPos( int nCP, int *pPrior )
{
    *pPrior = nCP;  // Default is the char itself

    HRESULT hr = S_OK;
    if( m_bAnalyseRequired )
        hr = Analyse();
    if( FAILED( hr ) )
        return;

    const SCRIPT_LOGATTR *pLogAttr = _ScriptString_pLogAttr( m_Analysis );
    if( !pLogAttr )
        return;

    if( !_ScriptString_pcOutChars( m_Analysis ) )
        return;
    int nInitial = *_ScriptString_pcOutChars( m_Analysis );
    if( nCP + 1 < nInitial )
        nInitial = nCP + 1;
    for( int i = nInitial; i < *_ScriptString_pcOutChars( m_Analysis ) - 1; ++i )
    {
        if( pLogAttr[i].fWordStop )      // Either the fWordStop flag is set
        {
            *pPrior = i;
            return;
        }
        else
        if( pLogAttr[i].fWhiteSpace &&  // Or this whitespace but the next char isn't.
            !pLogAttr[i+1].fWhiteSpace )
        {
            *pPrior = i+1;  // The next char is a word stop
            return;
        }
    }
    // We have reached the end. It's always a word stop, so simply return it.
    *pPrior = *_ScriptString_pcOutChars( m_Analysis ) - 1;
}