#include <QGuiApplication>

#include <QPainter>
#include <QQuickPaintedItem>
#include <QQuickWindow>

#include <windows.h>

class Paintable final : public QQuickPaintedItem
{
public:
  explicit Paintable(QQuickItem* parent = nullptr)
  : QQuickPaintedItem(parent)
  {
    setOpaquePainting(true);
  }

  void paint(QPainter* painter) override
  {
    QColor highlight{255, 0, 0, 50};

    painter->fillRect(QRect{QPoint{10, 0}, QSize{100, 100}}, highlight);
    painter->fillRect(QRect{QPoint{20, 20}, QSize{100, 100}}, highlight);
    painter->fillRect(QRect{QPoint{100, 100}, QSize{100, 100}}, highlight);
  }
};

QScreen* gscreen = nullptr;

class MyQWindow : public QQuickWindow
{
protected:
  void mousePressEvent(QMouseEvent*) override
  {
    float f = devicePixelRatio();
    float f1 = gscreen->devicePixelRatio();
    char s[100];
    sprintf(s, "Ratio=%g,%g\n", f, f1);
    OutputDebugStringA(s);
  }
};

MyQWindow* qquickWindow = nullptr;
HWND hWnd1 = NULL;

LRESULT WndProc1(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
#if 0
  if (msg == WM_DPICHANGED)
  {
    int dpi = HIWORD(wParam);
    int dpi1 = LOWORD(wParam);
  }
  if (msg == 0x2E2) // WM_DPICHANGED_BEFOREPARENT)
  {
    PostMessage(hWnd, WM_USER + 10, 0, 0);
    int dpi = HIWORD(wParam);
    int dpi1 = LOWORD(wParam);
  }
  if (msg == 0x2E3) // WM_DPICHANGED_AFTERPARENT)
  {
    int dpi = HIWORD(wParam);
    int dpi1 = LOWORD(wParam);
  }
  if (0) // msg == 0x2E3 ) //WM_USER+10 )
  {
    qquickWindow->destroy();
    qquickWindow = new MyQWindow();

    QWindow* qMain = QWindow::fromWinId((WId)hWnd1);
    qquickWindow->setParent(qMain);
    auto* paintable = new Paintable(qquickWindow->contentItem());
    paintable->setSize(QSize{1000, 1000});
    paintable->setVisible(true);
    qquickWindow->show();
  }
#endif
  return DefWindowProc(hWnd, msg, wParam, lParam);
}

int main(int argc, char* argv[])
{
  QGuiApplication app(argc, argv);

  AllocConsole();
  freopen("CONOUT$", "wt", stdout);
  printf("Qt test:\n");

  HINSTANCE hInst = GetModuleHandle(NULL);

  WNDCLASS wc = {};
  wc.hInstance = hInst;
  wc.lpfnWndProc = DefWindowProc;
  wc.hCursor = LoadCursor(NULL, IDC_ARROW);
  wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
  wc.lpszClassName = L"MyClass";
  RegisterClass(&wc);

  WNDCLASS wc1 = {};
  wc1.hInstance = hInst;
  wc1.lpfnWndProc = WndProc1;
  wc1.hCursor = LoadCursor(NULL, IDC_ARROW);
  wc1.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
  wc1.lpszClassName = L"MyClass1";
  RegisterClass(&wc1);

  HMODULE hUser32 = LoadLibrary(L"User32.dll");
  using SetThreadDpiAwarenessContextFuncType =
      DPI_AWARENESS_CONTEXT(WINAPI*)(DPI_AWARENESS_CONTEXT);
  using SetThreadDpiHostingBehaviourFuncType =
      DPI_HOSTING_BEHAVIOR(WINAPI*)(DPI_HOSTING_BEHAVIOR);
  auto setHostingBehavior = (SetThreadDpiHostingBehaviourFuncType)GetProcAddress(
      hUser32, "SetThreadDpiHostingBehavior");
  auto setDpiContext = (SetThreadDpiAwarenessContextFuncType)GetProcAddress(
      hUser32, "SetThreadDpiAwarenessContext");

  setDpiContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
  setHostingBehavior(DPI_HOSTING_BEHAVIOR_MIXED);
  HWND hWnd = CreateWindow(L"MyClass", L"WINAPI Window", WS_OVERLAPPEDWINDOW, 0, 0, 500, 500,
                           NULL, NULL, hInst, NULL);
  ShowWindow(hWnd, SW_NORMAL);

  hWnd1 = CreateWindow(L"MyClass1", L"WINAPI Window", WS_CHILD | WS_VISIBLE, 100, 100, 500, 500,
                       hWnd, NULL, hInst, NULL);
  qquickWindow = new MyQWindow();

  QWindow* qMain = QWindow::fromWinId((WId)hWnd1);
  qquickWindow->setParent(qMain);

  QScreen* screen = gscreen = qquickWindow->screen();
  QObject::connect(screen, &QScreen::logicalDotsPerInchChanged,
                   [screen, qwin=qquickWindow]()
                   {
                     printf("logicalDotsPerInchChanged: %.3f (QWindow: %.3f)\n",
                            screen->devicePixelRatio(), qwin->devicePixelRatio());
                   });
  QObject::connect(qquickWindow, &QWindow::screenChanged,
                   [qwin=qquickWindow](QScreen* screen) 
                   { 
                     printf("screenChanged: %.3f (QWindow: %.3f)\n",
                            screen ? screen->devicePixelRatio() : -1.0,
                            qwin->devicePixelRatio());
                     gscreen = screen;
                     if (screen)
                     {
                       QObject::connect(screen, &QScreen::logicalDotsPerInchChanged,
                                        [screen, qwin]() {
                                    printf("logicalDotsPerInchChanged: %.3f (QWindow: %.3f)\n",
                                    screen->devicePixelRatio(),
                                    qwin->devicePixelRatio());
                           });
                     }
                   });

  auto* paintable = new Paintable(qquickWindow->contentItem());
  paintable->setSize(QSize{1000, 1000});
  paintable->setVisible(true);
  qquickWindow->show();

  return app.exec();
}