#include "viewport.hxx"

#include <QApplication>
#include <QEvent>
#include <QGuiApplication>

Viewport::Viewport(QWidget* parent, Qt::WindowFlags f)
	: QWidget(parent, f) {
	setAttribute(Qt::WA_DontCreateNativeAncestors);
	setAttribute(Qt::WA_NativeWindow);
	setAttribute(Qt::WA_PaintOnScreen);
	setAttribute(Qt::WA_NoSystemBackground);
}

Viewport::~Viewport() = default;

void Viewport::setView(RedrawArgs new_args) {
	args = new_args;
	update();
}

QPaintEngine* Viewport::paintEngine() const {
	return nullptr;
}

bool Viewport::event(QEvent* event) {
	switch (event->type()) {
	case QEvent::Type::WinIdChange:
		recreate();
		break;
	default:
		break;
	}
	return QWidget::event(event);
}

void Viewport::paintEvent(QPaintEvent* event) {
	if (!core)
		recreate();
	core->redraw(args);
}

void Viewport::resizeEvent(QResizeEvent* event) {
	if (!core)
		return;
	updateSize();
	QWidget::resizeEvent(event);
}

void Viewport::recreate() try {
	auto* app = qobject_cast<QGuiApplication*>(QApplication::instance());
	if (!app)
		throw std::runtime_error("not a GUI application (WTF?)");

	auto* native = app->nativeInterface<QNativeInterface::QX11Application>();
	if (!native)
		throw std::runtime_error("X11 interface is not available");

	auto* xcb_connection = native->connection();
	std::uint32_t x11_window = winId();

	fprintf(stderr, "connection %p, window %#08x\n", xcb_connection, x11_window);

	core.reset();
	core = BoxCore::from_xcb(xcb_connection, x11_window);
	updateSize();
} catch (const std::exception& e) {
	fprintf(stderr, "failed to recreate the viewport: %s", e.what());
}

void Viewport::updateSize() {
	const QSize device_size = size() * devicePixelRatio();
	core->configure(device_size.width(), device_size.height());
}