#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <sddl.h>
#include <iostream>
#include <string>
#include <cctype>

int __cdecl wmain(int argc, wchar_t** argv)
{
	if(argc < 2)
	{
		std::wcout << L"Usage: Sid2String SidOrAcctName\n";
		return 1;
	}
	// if this isn't a sid
	if(!((towupper(argv[1][0]) == L'S') && (argv[1][1] == L'-')))
	{
		std::wstring account = argv[1];
		std::wstring system;
		std::wstring::size_type slashPos = account.find(L"\\");
		if(slashPos != std::wstring::npos)
		{
			system = account.substr(0, slashPos);
			account.erase(0, slashPos + 1);
		}
		DWORD sidReq = 0, domReq = 0;
		SID_NAME_USE snu = SidTypeUser;
		LPCWSTR systemStr = system.empty() ? NULL : system.c_str();
		LookupAccountName(
			systemStr,
			account.c_str(),
			NULL,
			&sidReq,
			NULL,
			&domReq,
			&snu
		);
		std::wstring domain(domReq, 0);
		BYTE sidBuffer[SECURITY_MAX_SID_SIZE] = {0};
		sidReq = ARRAYSIZE(sidBuffer);
		if(LookupAccountName(
				systemStr,
				account.c_str(),
				sidBuffer,
				&sidReq,
				&domain[0],
				&domReq,
				&snu
			)
		)
		{
			LPWSTR pStrSid = NULL;
			if(ConvertSidToStringSid(sidBuffer, &pStrSid))
			{
				std::wcout << L"Account " << argv[1] << L" has sid \"" << pStrSid << L"\"\n";
				LocalFree(pStrSid);
			}
			else
			{
				DWORD err = GetLastError();
				std::wcout << L"ConvertSidToStringSid failed with error " << err << L'\n';
			}
		}
		else
		{
			DWORD err = GetLastError();
			std::wcout << L"LookupAccountName failed with error " << err << L'\n';
		}
	}
	else
	{
		PSID pSid = NULL;
		if(ConvertStringSidToSid(argv[1], &pSid))
		{
			SID_NAME_USE snu;
			DWORD nameReq = 0, domReq = 0;
			LookupAccountSid(
				NULL,
				pSid,
				NULL,
				&nameReq,
				NULL,
				&domReq,
				&snu
			);
			std::wstring name(nameReq, 0), domain(domReq, 0);
			if(LookupAccountSid(
				NULL,
				pSid,
				&name[0],
				&nameReq,
				&domain[0],
				&domReq,
				&snu)
			)
			{
				domain.erase(domain.length() - 1);
				name.erase(name.length() - 1);
				std::wcout << L"SID " << argv[1] << L" is account \"" << domain << (domain.empty() ? L"" : L"\\") << name << L"\"\n";
			}
			else
			{
				DWORD err = GetLastError();
				std::wcout << L"LookupAccountSid failed for SID \"" << argv[1] << L"\" with error " << err << L'\n';
			}
			LocalFree(pSid);
		}
		else
		{
			DWORD err = GetLastError();
			std::wcout << L"ConvertStringSidToSid failed with error " << err << L'\n';
		}
	}
	return 0;
}