class XMTelestration:
	public InputHandler,
	public enable_defer,
	public std::enable_shared_from_this<XMTelestration>,
	public ControlChannelHubObserver

{
private:

	const int width = 1024;
	const int height = 1024;
	const float previewScale;

	PTR<ControlChannelHub> hub;
	PTR<XMRendererInterface> renderer;
	std::vector<PTR<XMTelestrationNode>> nodes;
	std::stack<PTR<XMTelestrationNode>> undoStack;
	std::map<int, PTR<XMTelestrationLine>> currentDrawings;
	Stroke stroke;
	PortableMutex<std::recursive_mutex> mtx;

	PTR<InvokeQueue> updateQueue;


	PTR<XMTelestrationLine> existingDrawingFor(int index);

	struct Layers
	{
		PTR<XMRendererSVGLayer> primary = nullptr;
		PTR<XMRendererSVGLayer> preview = nullptr;
	} layers;

	enum UpdateMode { Primary, Preview, Both };

	void updateLayers(UpdateMode mode);

	virtual void onMessage(ControlChannelHub* hub, PTR<XMUser> sender, ControlMessage* msg) override;

	void removeNode(const std::string& nodeId, bool redraw, bool notifyRemote);
	PTR<XMTelestrationNode> getNode(const std::string& nodeId);

	virtual void onTouchDown(int index, float x, float y) override;
	virtual void onTouchMoved(int index, float x, float y) override;
	virtual void onTouchReleased(int index) override;

public:
	XMTelestration(PTR<ControlChannelHub> hub, const Stroke& stroke, float previewScale);

	const std::vector<PTR<XMTelestrationNode>>& getNodes();
	void clear(bool notifyRemote = true);
	void undo();
	void attach(PTR<LayerFactoryInterface> layerFactory, PTR<XMRendererInterface> renderer);
	void detach();

	Stroke getStroke();
	void setStroke(const Stroke& stroke);

	static PTR<XMTelestration> create(PTR<ControlChannelHub> controlChannelHub, const Stroke& stroke, float previewScale);
};