// **************************************************************************
// * This file is part of the FreeFileSync project. It is distributed under *
// * GNU General Public License: http://www.gnu.org/licenses/gpl.html       *
// * Copyright (C) 2008-2011 ZenJu (zhnmju123 AT gmx.de)                    *
// **************************************************************************

#ifndef SHADOWCOPY_H
#define SHADOWCOPY_H

#ifdef SHADOWDLL_EXPORTS
#define SHADOWDLL_API extern "C" __declspec(dllexport)
#else
#define SHADOWDLL_API extern "C" __declspec(dllimport)
#endif

#include "../build_info.h"


namespace shadow
{
/*--------------
  |declarations|
  --------------*/

//COM needs to be initialized before calling any of these functions! CoInitializeEx/CoUninitialize

typedef size_t ShadowHandle;

//volumeName must end with "\", while shadowVolName does not end with "\"
SHADOWDLL_API
bool createShadowCopy(const wchar_t* volumeName,      //[in]
                      wchar_t*		 shadowVolName,   //[out]
                      unsigned int   shadowBufferLen, //[in]
                      ShadowHandle*	 handle,          //[out]
                      wchar_t*		 errorMessage,    //[out]
                      unsigned int	 errorBufferLen); //[in]


//don't forget to release the backupHandle after shadow copy is not needed anymore!
SHADOWDLL_API
void releaseShadowCopy(ShadowHandle handle);


//##########################################################################################


/*----------
  |typedefs|
  ----------*/
typedef bool (*CreateShadowCopyFct)(const wchar_t* volumeName,
                                    wchar_t*	   shadowVolName,
                                    unsigned int   shadowBufferLen,
                                    ShadowHandle*  handle,
                                    wchar_t*	   errorMessage,
                                    unsigned int   errorBufferLen);

typedef void (*ReleaseShadowCopyFct)(ShadowHandle handle);

/*--------------
  |symbol names|
  --------------*/
//(use const pointers to ensure internal linkage)
const char createShadowCopyFctName[]  = "createShadowCopy";
const char releaseShadowCopyFctName[] = "releaseShadowCopy";

/*---------------
  |library names|
  ---------------*/
namespace impl
{
bool newerThanXP()
{
    OSVERSIONINFO osvi = {};
    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);

    if (::GetVersionEx(&osvi))
        return osvi.dwMajorVersion > 5 ||
               (osvi.dwMajorVersion == 5 && osvi.dwMinorVersion > 1) ;
    //XP          has majorVersion == 5, minorVersion == 1
    //Server 2003 has majorVersion == 5, minorVersion == 2
    //version overview: http://msdn.microsoft.com/en-us/library/ms724834(VS.85).aspx
    return false;
}
}

inline
const wchar_t* getDllName()
{
    /*
    distinguish a bunch of VSS builds: we use XP and Server 2003 implementations...
    VSS version and compatibility overview: http://msdn.microsoft.com/en-us/library/aa384627(VS.85).aspx
    */
    return impl::newerThanXP() ?
           (util::is64BitBuild ?
            L"Shadow_Server2003_x64.dll" :
            L"Shadow_Server2003_Win32.dll") :

               (util::is64BitBuild ?
                L"Shadow_XP_x64.dll" :
                L"Shadow_XP_Win32.dll");
}
}



#endif //SHADOWCOPY_H