#include <Windows.h>
#include <GdiPlus.h>
#include <sstream>

LRESULT CALLBACK WindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_DESTROY:
        {
            PostQuitMessage(0);

            return 0;
            break;
        }
    case WM_PAINT:
        {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hwnd, &ps);

            Gdiplus::Graphics graphics(hdc);

            RECT clientRect;
            GetClientRect(hwnd, &clientRect);

            Gdiplus::LinearGradientBrush brush(Gdiplus::PointF(clientRect.left, clientRect.top),
                Gdiplus::PointF(clientRect.left, clientRect.bottom),
                Gdiplus::Color(0, 0, 0),
                Gdiplus::Color(80, 160, 240));

            __int64 before, after, freq;
            QueryPerformanceFrequency((LARGE_INTEGER *)&freq);
            QueryPerformanceCounter((LARGE_INTEGER *)&before);

            graphics.FillRectangle(&brush, clientRect.left, clientRect.top, clientRect.right - clientRect.left, clientRect.bottom - clientRect.top);

            QueryPerformanceCounter((LARGE_INTEGER *)&after);

            std::stringstream s;
            s << "Wypełnienie gradientem: " << (((after - before) * 1000) / freq) << "\n";
            OutputDebugStringA(s.str().c_str());

            EndPaint(hwnd, &ps);
            return 0L;
        }
    default:
        {
            return DefWindowProc(hwnd, message, wParam, lParam);
        }
    }
}

int CALLBACK WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    // *** GDI+ ***

    ULONG_PTR gdiPlusToken;
    Gdiplus::Status result;

    Gdiplus::GdiplusStartupInput gdiplusStartupInput;
    result = Gdiplus::GdiplusStartup(&gdiPlusToken, &gdiplusStartupInput, NULL);

    // *** Koniec GDI+ ***

    // Rejestracja klasy okna
    WNDCLASSEX winClass;
    winClass.cbClsExtra = 0;
    winClass.cbSize = sizeof(WNDCLASSEX);
    winClass.cbWndExtra = 0;
    winClass.hbrBackground = (HBRUSH)(COLOR_BTNFACE + 1);
    winClass.hCursor = LoadCursor(NULL, IDC_ARROW);
    winClass.hIcon = LoadIcon(NULL, IDI_WINLOGO);
    winClass.hIconSm = LoadIcon(NULL, IDI_WINLOGO);
    winClass.hInstance = hInstance;
    winClass.lpfnWndProc = WindowProc;
    winClass.lpszClassName = L"MainWindowClass";
    winClass.lpszMenuName = NULL;
    winClass.style = CS_HREDRAW | CS_VREDRAW;

    if (!RegisterClassEx(&winClass))
        return -1;

    // Tworzenie okna
    HWND mainWinHWND = CreateWindowEx(WS_EX_WINDOWEDGE | WS_EX_CLIENTEDGE,
        L"MainWindowClass",
        L"WinAPI window",
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        640,
        480,
        NULL,
        NULL,
        hInstance,
        NULL);

    if (!mainWinHWND)
        return -1;

    ShowWindow(mainWinHWND, SW_SHOW);

    // Obsługa kolejki komunikatów
    MSG message;
    BOOL getMsgResult;

    while ((getMsgResult = GetMessage(&message, NULL, 0, 0)) != 0 && getMsgResult != -1)
    {
        TranslateMessage(&message);
        DispatchMessage(&message);
    }

    // *** GDI+ ***

    Gdiplus::GdiplusShutdown(gdiPlusToken);

    // *** GDI+ ***

    return message.lParam;
}