#pragma once
class CVMTHookManager
{
public:
    CVMTHookManager( void )
    {
        memset( this, 0, sizeof( CVMTHookManager ) );
    }

    CVMTHookManager( PDWORD* ppdwClassBase )
    {
        bInitialize( ppdwClassBase );
    }

    ~CVMTHookManager( void )
    {
        UnHook( );
    }
    bool bInitialize( PDWORD* ppdwClassBase )
    {
        m_ppdwClassBase = ppdwClassBase;
        m_pdwOldVMT = *ppdwClassBase;
        m_dwVMTSize = dwGetVMTCount( *ppdwClassBase );
        m_pdwNewVMT = new DWORD[ m_dwVMTSize ];
        memcpy( m_pdwNewVMT, m_pdwOldVMT, sizeof( DWORD ) * m_dwVMTSize );
        *ppdwClassBase = m_pdwNewVMT;
        return true;
    }
    bool bInitialize( PDWORD** pppdwClassBase ) // fix for pp
    {
        return bInitialize( *pppdwClassBase );
    }

    void UnHook( void )
    {
        if ( m_ppdwClassBase )
        {
            *m_ppdwClassBase = m_pdwOldVMT;
        }
    }

    void ReHook( void )
    {
        if ( m_ppdwClassBase )
        {
            *m_ppdwClassBase = m_pdwNewVMT;
        }
    }

    int iGetFuncCount( void )
    {
        return (int)m_dwVMTSize;
    }

    DWORD dwGetMethodAddress( int Index )
    {
        if ( Index >= 0 && Index <= (int)m_dwVMTSize && m_pdwOldVMT != NULL )
        {
            return m_pdwOldVMT[ Index ];
        }
        return NULL;
    }

    PDWORD pdwGetOldVMT( void )
    {
        return m_pdwOldVMT;
    }

    DWORD dwHookMethod( DWORD dwNewFunc, unsigned int iIndex )
    {
        if ( m_pdwNewVMT && m_pdwOldVMT && iIndex <= m_dwVMTSize && iIndex >= 0 )
        {
            m_pdwNewVMT[ iIndex ] = dwNewFunc;
            return m_pdwOldVMT[ iIndex ];
        }

        return NULL;
    }

private:
    DWORD dwGetVMTCount( PDWORD pdwVMT )
    {
        DWORD dwIndex = 0;

        for ( dwIndex = 0; pdwVMT[ dwIndex ]; dwIndex++ )
        {
            if ( IsBadCodePtr( (FARPROC)pdwVMT[ dwIndex ] ) )
            {
                break;
            }
        }
        return dwIndex;
    }
    PDWORD*	m_ppdwClassBase;
    PDWORD	m_pdwNewVMT, m_pdwOldVMT;
    DWORD	m_dwVMTSize;
};