// Use the following command to compile.
// cl /MD /EHsc appumid.cpp

// For Application User Model IDs documentation
// see http://msdn.microsoft.com/en-us/library/dd378459%28VS.85%29.aspx

#if 1
#define UNICODE
#define _UNICODE
#else
#undef UNICODE
#undef _UNICODE
#endif
#include <stdio.h>
#include <locale.h>
#include <windows.h>
#include <tchar.h>
// #include <shellapi.h>
#include <shlobj.h>
// #include <shobjidl.h>
// #include <shlguid.h>
// #include <propsys.h>
#include <propkey.h>
// #include <propidl.h>
#include <propvarutil.h>
// #include <comip.h>
#include <comdef.h>

// #pragma comment(lib, "user32.lib")
// #pragma comment(lib, "shell32.lib")
// #pragma comment(lib, "ole32.lib")
// #pragma comment(lib, "comsupp.lib")
#pragma comment(lib, "propsys.lib")
#pragma comment(lib, "shlwapi.lib")

_COM_SMARTPTR_TYPEDEF(IShellLink, IID_IShellLink);
_COM_SMARTPTR_TYPEDEF(IPropertyStore, IID_IPropertyStore);

#define PRINTF _tprintf
#define ASSERT(x) do{ if(!(x)){ PRINTF(_T("ASSERT(%s) error at line %d of %s\n"), __LINE__, _T(__FILE__)); } }while(0)
#define NUMBER_OF(x) (sizeof(x)/sizeof(*(x)))

void ShowShellLinkAndChangeAppUserModel_ID(LPTSTR lnk_fname, LPTSTR app_id)
{
	HRESULT hres;
	int len;
	IShellLinkPtr pSl;
	IPersistFilePtr pPf;
	IPropertyStorePtr pPs;
	wchar_t wsz_path[256];
	wchar_t wsz_buf[256];
	TCHAR buf[256];
	int id;
	LPITEMIDLIST pidl;
	PROPVARIANT prop_variant = { VT_EMPTY };

	pSl.CreateInstance(CLSID_ShellLink, NULL, CLSCTX_INPROC_SERVER);
	pPs = pPf = pSl;
	if(!pPs)
		goto leave;

#ifndef _UNICODE
	len = MultiByteToWideChar(CP_ACP, 0, lnk_fname, -1, wsz_path, NUMBER_OF(wsz_path));
	ASSERT(len != 0);
#else
	_tcscpy(wsz_path, lnk_fname);
#endif

	hres = pPf->Load(wsz_path, STGM_READWRITE);
	if(FAILED(hres))
		goto leave;

	hres = pSl->GetPath(buf, NUMBER_OF(buf), NULL, SLGP_RAWPATH);
	if(FAILED(hres))
		goto leave;
	if(buf[0] == 0){
		PRINTF(_T("No Path\n"));
	}else{
		PRINTF(_T("Path = %s\n"), buf);
	}

	hres = pSl->GetIconLocation(buf, NUMBER_OF(buf), &id);
	if(FAILED(hres))
		goto leave;
	if(buf[0] == 0){
		PRINTF(_T("No IconLocation\n"));
	}else{
		PRINTF(_T("IconLocation = %s : %d\n"), buf,id);
	}

	hres = pSl->GetDescription(buf, NUMBER_OF(buf));
	if(FAILED(hres))
		goto leave;
	if(buf[0] == 0){
		PRINTF(_T("No Description\n"));
	}else{
		PRINTF(_T("Description = %s\n"), buf);
	}

	hres = pPs->GetValue(PKEY_AppUserModel_ID, &prop_variant);
	ASSERT(SUCCEEDED(hres));

	hres = PropVariantToString(prop_variant, wsz_buf, NUMBER_OF(wsz_buf));
	ASSERT(SUCCEEDED(hres));
	PRINTF(_T("AppUserModel_ID = %ls\n"), wsz_buf);
	
	hres = PropVariantClear(&prop_variant);
	ASSERT(SUCCEEDED(hres));

	if(!app_id)
		goto leave;

	if(app_id[0] != 0){
#ifndef _UNICODE
		len = MultiByteToWideChar(CP_ACP, 0, app_id, -1, wsz_buf, NUMBER_OF(wsz_buf));
		ASSERT(len != 0);
		hres = InitPropVariantFromString(wsz_buf, &prop_variant);
		ASSERT(SUCCEEDED(hres));
#else
		hres = InitPropVariantFromString(app_id, &prop_variant);
		ASSERT(SUCCEEDED(hres));
#endif
	}

	hres = pPs->SetValue(PKEY_AppUserModel_ID, prop_variant);
	if(FAILED(hres))
		goto leave;

	hres = PropVariantClear(&prop_variant);
	ASSERT(SUCCEEDED(hres));

	hres = pPs->Commit();
	if(FAILED(hres))
		goto leave;

	hres = pPf->Save(wsz_path, TRUE);
	if(FAILED(hres))
		goto leave;

	PRINTF(_T("Successfully changed AppUserModel_ID\n"));

leave:
	;
}

int _tmain( int argc, TCHAR **argv)
{
	setlocale(LC_ALL, "");

	if(argc < 2 || argc > 3){
		PRINTF(_T("USAGE: appumid lnk_file [AppID]\n"));
		return 1;
	}

	CoInitialize(NULL);

	try{
		if(argc == 2){
			ShowShellLinkAndChangeAppUserModel_ID(argv[1], NULL);
		}else if(argc == 3){
			ShowShellLinkAndChangeAppUserModel_ID(argv[1], argv[2]);
		}
	}
	catch(_com_error &e){
		PRINTF(_T("_com_error: HRESULT = %08X\n"), e.Error());
	}

	CoUninitialize();

	return 0;
}