/************************************************************************************
Copyright : Copyright (c) Facebook Technologies, LLC and its affiliates. All rights reserved.

Your use of this SDK or tool is subject to the Oculus SDK License Agreement, available at
https://developer.oculus.com/licenses/oculussdk/

Unless required by applicable law or agreed to in writing, the Utilities SDK distributed
under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
ANY KIND, either express or implied. See the License for the specific language governing
permissions and limitations under the License.
************************************************************************************/

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[DefaultExecutionOrder(-90)]
public class OVRHand : MonoBehaviour,
	OVRSkeleton.IOVRSkeletonDataProvider,
	OVRSkeletonRenderer.IOVRSkeletonRendererDataProvider,
	OVRMesh.IOVRMeshDataProvider,
	OVRMeshRenderer.IOVRMeshRendererDataProvider
{
	public enum Hand
	{
		None      = OVRPlugin.Hand.None,
		HandLeft  = OVRPlugin.Hand.HandLeft,
		HandRight = OVRPlugin.Hand.HandRight,
	}

	public enum HandFinger
	{
		Thumb  = OVRPlugin.HandFinger.Thumb,
		Index  = OVRPlugin.HandFinger.Index,
		Middle = OVRPlugin.HandFinger.Middle,
		Ring   = OVRPlugin.HandFinger.Ring,
		Pinky  = OVRPlugin.HandFinger.Pinky,
		Max    = OVRPlugin.HandFinger.Max,
	}

	public enum TrackingConfidence
	{
		Low  = OVRPlugin.TrackingConfidence.Low,
		High = OVRPlugin.TrackingConfidence.High
	}

	[SerializeField]
	private Hand HandType = Hand.None;
	[SerializeField]
	private Transform _pointerPoseRoot = null;
	private GameObject _pointerPoseGO;
	private OVRPlugin.HandState _handState = new OVRPlugin.HandState();

	public bool IsDataValid { get; private set; }
	public bool IsDataHighConfidence { get; private set; }
	public bool IsTracked { get; private set; }
	public bool IsSystemGestureInProgress { get; private set; }
	public bool IsPointerPoseValid { get; private set; }
	public Transform PointerPose { get; private set; }
	public float HandScale { get; private set; }
	public TrackingConfidence HandConfidence { get; private set; }
	public bool IsDominantHand { get; private set; }

	private void Awake()
	{
		_pointerPoseGO = new GameObject();
		PointerPose = _pointerPoseGO.transform;
		if (_pointerPoseRoot != null)
		{
			PointerPose.SetParent(_pointerPoseRoot, false);
		}

		GetHandState(OVRPlugin.Step.Render);
	}

	private void Update()
	{
		GetHandState(OVRPlugin.Step.Render);
	}

	private void FixedUpdate()
	{
		if (OVRPlugin.nativeXrApi != OVRPlugin.XrApi.OpenXR)
		{
			GetHandState(OVRPlugin.Step.Physics);
		}
	}

	private void GetHandState(OVRPlugin.Step step)
	{
		if (OVRPlugin.GetHandState(step, (OVRPlugin.Hand)HandType, ref _handState))
		{
			IsTracked = (_handState.Status & OVRPlugin.HandStatus.HandTracked) != 0;
			IsSystemGestureInProgress = (_handState.Status & OVRPlugin.HandStatus.SystemGestureInProgress) != 0;
			IsPointerPoseValid = (_handState.Status & OVRPlugin.HandStatus.InputStateValid) != 0;
			IsDominantHand = (_handState.Status & OVRPlugin.HandStatus.DominantHand) != 0;
			PointerPose.localPosition = _handState.PointerPose.Position.FromFlippedZVector3f();
			PointerPose.localRotation = _handState.PointerPose.Orientation.FromFlippedZQuatf();
			HandScale = _handState.HandScale;
			HandConfidence = (TrackingConfidence)_handState.HandConfidence;

			IsDataValid = true;
			IsDataHighConfidence = IsTracked && HandConfidence == TrackingConfidence.High;
		}
		else
		{
			IsTracked = false;
			IsSystemGestureInProgress = false;
			IsPointerPoseValid = false;
			PointerPose.localPosition = Vector3.zero;
			PointerPose.localRotation = Quaternion.identity;
			HandScale = 1.0f;
			HandConfidence = TrackingConfidence.Low;

			IsDataValid = false;
			IsDataHighConfidence = false;
		}
	}

	public bool GetFingerIsPinching(HandFinger finger)
	{
		return IsDataValid && (((int)_handState.Pinches & (1 << (int)finger)) != 0);
	}

	public float GetFingerPinchStrength(HandFinger finger)
	{
		if (IsDataValid
			&& _handState.PinchStrength != null
			&& _handState.PinchStrength.Length == (int)OVRPlugin.HandFinger.Max)
		{
			return _handState.PinchStrength[(int)finger];
		}

		return 0.0f;
	}

	public TrackingConfidence GetFingerConfidence(HandFinger finger)
	{
		if (IsDataValid
			&& _handState.FingerConfidences != null
			&& _handState.FingerConfidences.Length == (int)OVRPlugin.HandFinger.Max)
		{
			return (TrackingConfidence)_handState.FingerConfidences[(int)finger];
		}

		return TrackingConfidence.Low;
	}

	OVRSkeleton.SkeletonType OVRSkeleton.IOVRSkeletonDataProvider.GetSkeletonType()
	{
		switch (HandType)
		{
		case Hand.HandLeft:
			return OVRSkeleton.SkeletonType.HandLeft;
		case Hand.HandRight:
			return OVRSkeleton.SkeletonType.HandRight;
		case Hand.None:
		default:
			return OVRSkeleton.SkeletonType.None;
		}
	}

	OVRSkeleton.SkeletonPoseData OVRSkeleton.IOVRSkeletonDataProvider.GetSkeletonPoseData()
	{
		var data = new OVRSkeleton.SkeletonPoseData();

		data.IsDataValid = IsDataValid;
		if (IsDataValid)
		{
			data.RootPose = _handState.RootPose;
			data.RootScale = _handState.HandScale;
			data.BoneRotations = _handState.BoneRotations;
			data.IsDataHighConfidence = IsTracked && HandConfidence == TrackingConfidence.High;
		}

		return data;
	}

	OVRSkeletonRenderer.SkeletonRendererData OVRSkeletonRenderer.IOVRSkeletonRendererDataProvider.GetSkeletonRendererData()
	{
		var data = new OVRSkeletonRenderer.SkeletonRendererData();

		data.IsDataValid = IsDataValid;
		if (IsDataValid)
		{
			data.RootScale = _handState.HandScale;
			data.IsDataHighConfidence = IsTracked && HandConfidence == TrackingConfidence.High;
			data.ShouldUseSystemGestureMaterial = IsSystemGestureInProgress;
		}

		return data;
	}

	OVRMesh.MeshType OVRMesh.IOVRMeshDataProvider.GetMeshType()
	{
		switch (HandType)
		{
		case Hand.None:
			return OVRMesh.MeshType.None;
		case Hand.HandLeft:
			return OVRMesh.MeshType.HandLeft;
		case Hand.HandRight:
			return OVRMesh.MeshType.HandRight;
		default:
			return OVRMesh.MeshType.None;
		}
	}

	OVRMeshRenderer.MeshRendererData OVRMeshRenderer.IOVRMeshRendererDataProvider.GetMeshRendererData()
	{
		var data = new OVRMeshRenderer.MeshRendererData();

		data.IsDataValid = IsDataValid;
		if (IsDataValid)
		{
			data.IsDataHighConfidence = IsTracked && HandConfidence == TrackingConfidence.High;
			data.ShouldUseSystemGestureMaterial = IsSystemGestureInProgress;
		}

		return data;
	}
}