// Copyright 2023 PICO Inc. All Rights Reserved.

#pragma once

#include "CoreMinimal.h"
#include "PICO_MovementFunctionLibrary.h"
#include "IOpenXRExtensionPlugin.h"

class FBodyTrackingPICO : public IOpenXRExtensionPlugin
{
public:
	FBodyTrackingPICO();
	virtual ~FBodyTrackingPICO() {}

	void Register();
	void Unregister();

	/** IOpenXRExtensionPlugin */
	virtual FString GetDisplayName() override
	{
		return FString(TEXT("BodyTrackingPICO"));
	}
	virtual bool GetRequiredExtensions(TArray<const ANSICHAR*>& OutExtensions) override;
	virtual const void* OnGetSystem(XrInstance InInstance, const void* InNext) override;
	virtual void PostGetSystem(XrInstance InInstance, XrSystemId InSystem) override;
	virtual void PostCreateSession(XrSession InSession) override;
	virtual void UpdateDeviceLocations(XrSession InSession, XrTime DisplayTime, XrSpace TrackingSpace) override;
	
	bool TryGetBodyState(FBodyStatePICO& outBodyState, float WorldToMeters = 100.0f);
	bool IsBodyTrackingEnabled();
	bool IsBodyTrackingSupported();
	bool StartBodyTracking(EBodyTrackingModePICO Mode);
	bool StopBodyTracking();

private:

	PFN_xrCreateBodyTrackerBD xrCreateBodyTrackerBD = nullptr;
	PFN_xrDestroyBodyTrackerBD xrDestroyBodyTrackerBD = nullptr;
	PFN_xrLocateBodyJointsBD xrLocateBodyJointsBD = nullptr;
	bool bCurrentDeviceSupportBodyTracking = false;
	XrInstance Instance = XR_NULL_HANDLE;
	XrSession Session = XR_NULL_HANDLE;
	XrBodyTrackerBD BodyTracker = XR_NULL_HANDLE;
	bool bBodyTrackerIsRunning = false;
	XrTime PredictedTime = 0;
	XrSpace BaseSpace = XR_NULL_HANDLE;
	TArray<XrBodyJointLocationBD> Locations;
};