#include <windows.h>
#include <lmcons.h>
#include <string.h>
#include <stdio.h>
#include <string>
#include <strsafe.h>

TCHAR cName[MAX_COMPUTERNAME_LENGTH+1];	// computer name
DWORD cLen = sizeof(cName);				// length

TCHAR uName[UNLEN+1];					// username
DWORD uLen = sizeof(uName);				// length

TCHAR pAmount[4], sVer[5];				// processors count, OS version
LPCWSTR pType, osName;					// processor type, OS name

SYSTEM_INFO sInfo;						// system info struct
OSVERSIONINFOEX osInfo;					// OS version struct

// processor name depends on wProcessorArchitecture
void GetProcessorType()
{
	pType = L"Unknown";

	switch(sInfo.wProcessorArchitecture)
	{
	case PROCESSOR_ARCHITECTURE_AMD64:
		pType = L"AMD64";
		break;
	case PROCESSOR_ARCHITECTURE_IA32_ON_WIN64:
		pType = L"WOW64";
		break;
	case PROCESSOR_ARCHITECTURE_IA64:
		pType = L"Itanium"; 
		break;
	case PROCESSOR_ARCHITECTURE_INTEL:
		pType = L"x86";
		break;
	default:
		break;	
	}
}

// OS name depends on dwMajorVersion and dwMinorVersion
void GetOSName()
{
	osName = L"Unknown";

	switch(osInfo.dwMajorVersion)
	{
	case 5:
		if (osInfo.dwMinorVersion == 0)
			osName = L"Windows 2000";
		if (osInfo.dwMinorVersion == 1)
			osName = L"Windows XP";
		if (osInfo.dwMinorVersion == 2)
			osName = L"Windows Server";
		if (osInfo.dwMinorVersion == 2 && osInfo.wProductType == VER_NT_WORKSTATION && sInfo.wProcessorArchitecture == PROCESSOR_ARCHITECTURE_AMD64)
			osName = L"Windows XP Professional x64 Edition";
		break;
	case 6:
		if (osInfo.dwMinorVersion == 0)
			if (osInfo.wProductType == VER_NT_WORKSTATION)
				osName = L"Windows Vista";
			else
				osName = L"Windows Server 2008";
		if (osInfo.dwMinorVersion == 1)
			if (osInfo.wProductType == VER_NT_WORKSTATION)
				osName = L"Windows 7";
			else
				osName = L"Windows Server 2008 R2";
		if (osInfo.dwMinorVersion == 2)
			if (osInfo.wProductType == VER_NT_WORKSTATION)
				osName = L"Windows 8";
			else
				osName = L"Windows Server 2012";
		if (osInfo.dwMinorVersion == 3)
			if (osInfo.wProductType == VER_NT_WORKSTATION)
				osName = L"Windows 8.1 Preview";
			else
				osName = L"Windows Server 2012 R2 Preview";
		break;
	}
}

LONG WINAPI WndProc(HWND, UINT, WPARAM,LPARAM);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    HWND hwnd;
    MSG msg;
    WNDCLASS w;
    memset(&w, 0, sizeof(WNDCLASS));
    w.style = WS_TILED | CS_HREDRAW | CS_VREDRAW;
    w.lpfnWndProc = WndProc;
    w.hInstance = hInstance;
	w.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    w.lpszClassName = L"Lab1";
	w.hIcon = LoadIcon(NULL, IDI_EXCLAMATION);
    RegisterClass(&w);
    hwnd = CreateWindow(L"Lab1", L"Petryakov 3120", WS_OVERLAPPEDWINDOW, 400, 400, 240, 160, NULL, NULL, hInstance, NULL);
	
	// get system info
	ZeroMemory(&sInfo, sizeof(SYSTEM_INFO));
	GetSystemInfo(&sInfo);
	// format string
	StringCbPrintf(pAmount, sizeof(pAmount), L"%u", sInfo.dwNumberOfProcessors);
	// get processor type readable format
	GetProcessorType();

	//get OS version
	ZeroMemory(&osInfo, sizeof(OSVERSIONINFOEX));
	osInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFOEX);
	GetVersionEx((OSVERSIONINFO*)&osInfo);
	// format full version string
	StringCbPrintf((LPWSTR)sVer, sizeof(sVer), L"%u.%u", osInfo.dwMajorVersion, osInfo.dwMinorVersion);
	// get readable version name string
	GetOSName();

	GetComputerName(cName, &cLen);	// get computer name in cName, cLen is length of max name / result length
	GetUserName(uName, &uLen);		// get username like computer name

    ShowWindow(hwnd,nCmdShow);
    UpdateWindow(hwnd);
	
	while(GetMessage(&msg,NULL,0,0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    
	return msg.wParam;
}

LONG WINAPI WndProc(HWND hwnd, UINT Message, WPARAM wparam, LPARAM lparam)
{
	HDC hdc;
	PAINTSTRUCT ps;
	int start = 5;

    switch (Message){
    case WM_DESTROY: 
        PostQuitMessage(0);
        break;
	case WM_PAINT:
		hdc = BeginPaint(hwnd, &ps);
		
		TextOut(hdc, 5, start, L"Processors:", 11);
		TextOut(hdc, 100, start, pAmount, wcslen(pAmount));
		
		TextOut(hdc, 5, start+20, L"Type:", 5);
		TextOut(hdc, 100, start+20, pType, wcslen(pType));
		
		TextOut(hdc, 5, start+40, L"OS Version:", 11);
		TextOut(hdc, 100, start+40, sVer, wcslen(sVer));

		TextOut(hdc, 5, start+60, L"OS Name:", 8);
		TextOut(hdc, 100, start+60, osName, wcslen(osName));

		TextOut(hdc, 5, start+80, L"Hostname:", 9);
		TextOut(hdc, 100, start+80, cName, cLen);
		
		TextOut(hdc, 5, start+100, L"Username:", 9);
		TextOut(hdc, 100, start+100, uName, uLen-1);

		EndPaint(hwnd, &ps);
		break;
    default:
        return DefWindowProc(hwnd, Message, wparam, lparam);
    }

    return 0;
}