#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <tchar.h>

#include <cairo/cairo-win32.h>

const wchar_t *windowClass = L"cairo_window";

const double alpha = 1.0;

void cairoPaint(HDC hdc) {
    cairo_surface_t *paintSurface = cairo_win32_surface_create(hdc);
    cairo_t *cr = cairo_create(paintSurface);

    cairo_set_source_rgba(cr,
        0.0, 0.0, 0.0,
        alpha);
    cairo_rectangle(cr,
        10.0, 10.0,
        50.0, 50.0);
    cairo_fill(cr);

    cairo_destroy(cr);
    cairo_surface_destroy(paintSurface);
}

LRESULT CALLBACK windowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) {
    PAINTSTRUCT ps;
    HDC hdc;

	switch (message) {
        case WM_PAINT:
	        hdc = BeginPaint(hWnd, &ps);
	        cairoPaint(hdc);
	        EndPaint(hWnd, &ps);
	        break;

        case WM_DESTROY:
	        PostQuitMessage(0);
	        break;

        default:
	        return DefWindowProc(hWnd, message, wParam, lParam);
	}

	return 0;
}

void registerWindowClass(HINSTANCE hInstance) {
	WNDCLASSEX wcex;

	wcex.cbSize = sizeof(WNDCLASSEX);

	wcex.style			= CS_HREDRAW | CS_VREDRAW;
	wcex.lpfnWndProc	= windowProc;
	wcex.cbClsExtra		= 0;
	wcex.cbWndExtra		= 0;
	wcex.hInstance		= hInstance;
	wcex.hIcon			= NULL;
	wcex.hCursor		= LoadCursor(NULL, IDC_ARROW);
	wcex.hbrBackground	= (HBRUSH)(COLOR_WINDOW+1);
	wcex.lpszMenuName	= NULL;
	wcex.lpszClassName	= windowClass;
	wcex.hIconSm		= NULL;

	RegisterClassEx(&wcex);
}

BOOL initInstance(HINSTANCE hInstance, int nCmdShow) {
   HWND hWnd = CreateWindow(
       windowClass,
       L"Cairo Window",
       WS_OVERLAPPEDWINDOW,
       CW_USEDEFAULT,
       0,
       400,
       200,
       NULL,
       NULL,
       hInstance,
       NULL);

   if (!hWnd)
      return FALSE;

   ShowWindow(hWnd, nCmdShow);
   UpdateWindow(hWnd);

   return TRUE;
}

int APIENTRY _tWinMain(
    HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPTSTR lpCmdLine,
    int nCmdShow) {

	registerWindowClass(hInstance);

	if (!initInstance(hInstance, nCmdShow))
	    return FALSE;

    MSG msg;
	while (GetMessage(&msg, NULL, 0, 0)) {
	    TranslateMessage(&msg);
		DispatchMessage(&msg);
	}

	return (int) msg.wParam;
}