/************************************************************************************
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;

public class OVRMeshRenderer : MonoBehaviour
{
	public interface IOVRMeshRendererDataProvider
	{
		MeshRendererData GetMeshRendererData();
	}

	public struct MeshRendererData
	{
		public bool IsDataValid { get; set; }
		public bool IsDataHighConfidence { get; set; }
		public bool ShouldUseSystemGestureMaterial { get; set; }
	}

	public enum ConfidenceBehavior
	{
		None,
		ToggleRenderer,
	}

	public enum SystemGestureBehavior
	{
		None,
		SwapMaterial,
	}

	[SerializeField]
	private IOVRMeshRendererDataProvider _dataProvider;
	[SerializeField]
	private OVRMesh _ovrMesh;
	[SerializeField]
	private OVRSkeleton _ovrSkeleton;
	[SerializeField]
	private ConfidenceBehavior _confidenceBehavior = ConfidenceBehavior.ToggleRenderer;
	[SerializeField]
	private SystemGestureBehavior _systemGestureBehavior = SystemGestureBehavior.SwapMaterial;
	[SerializeField]
	private Material _systemGestureMaterial = null;
	private Material _originalMaterial = null;

	private SkinnedMeshRenderer _skinnedMeshRenderer;

	public bool IsInitialized { get; private set; }
	public bool IsDataValid { get; private set; }
	public bool IsDataHighConfidence { get; private set; }
	public bool ShouldUseSystemGestureMaterial { get; private set; }

	private void Awake()
	{
		if (_dataProvider == null)
		{
			_dataProvider = GetComponent<IOVRMeshRendererDataProvider>();
		}

		if (_ovrMesh == null)
		{
			_ovrMesh = GetComponent<OVRMesh>();
		}

		if (_ovrSkeleton == null)
		{
			_ovrSkeleton = GetComponent<OVRSkeleton>();
		}
	}

	private void Start()
	{
		if (_ovrMesh == null)
		{
			// disable if no mesh configured
			this.enabled = false;
			return;
		}

		if (ShouldInitialize())
		{
			Initialize();
		}
	}

	private bool ShouldInitialize()
	{
		if (IsInitialized)
		{
			return false;
		}

		if ((_ovrMesh == null) || ((_ovrMesh != null) && !_ovrMesh.IsInitialized) || ((_ovrSkeleton != null) && !_ovrSkeleton.IsInitialized))
		{
			// do not initialize if mesh or optional skeleton are not initialized
			return false;
		}

		return true;
	}

	private void Initialize()
	{
		_skinnedMeshRenderer = GetComponent<SkinnedMeshRenderer>();
		if (!_skinnedMeshRenderer)
		{
			_skinnedMeshRenderer = gameObject.AddComponent<SkinnedMeshRenderer>();
		}

		_skinnedMeshRenderer.sharedMesh = _ovrMesh.Mesh;
		_originalMaterial = _skinnedMeshRenderer.sharedMaterial;

		if ((_ovrSkeleton != null))
		{
			int numSkinnableBones = _ovrSkeleton.GetCurrentNumSkinnableBones();
			var bindPoses = new Matrix4x4[numSkinnableBones];
			var bones = new Transform[numSkinnableBones];
			var localToWorldMatrix = transform.localToWorldMatrix;
			for (int i = 0; i < numSkinnableBones && i < _ovrSkeleton.Bones.Count; ++i)
			{
				bones[i] = _ovrSkeleton.Bones[i].Transform;
				bindPoses[i] = _ovrSkeleton.BindPoses[i].Transform.worldToLocalMatrix * localToWorldMatrix;
			}
			_ovrMesh.Mesh.bindposes = bindPoses;
			_skinnedMeshRenderer.bones = bones;
			_skinnedMeshRenderer.updateWhenOffscreen = true;
		}

		IsInitialized = true;
	}

	private void Update()
	{
#if UNITY_EDITOR
		if (ShouldInitialize())
		{
			Initialize();
		}
#endif

		IsDataValid = false;
		IsDataHighConfidence = false;
		ShouldUseSystemGestureMaterial = false;

		if (IsInitialized)
		{
			bool shouldRender = false;

			if (_dataProvider != null)
			{
				var data = _dataProvider.GetMeshRendererData();

				IsDataValid = data.IsDataValid;
				IsDataHighConfidence = data.IsDataHighConfidence;
				ShouldUseSystemGestureMaterial = data.ShouldUseSystemGestureMaterial;

				shouldRender = data.IsDataValid && data.IsDataHighConfidence;
			}

			if (_confidenceBehavior == ConfidenceBehavior.ToggleRenderer)
			{
				if (_skinnedMeshRenderer != null && _skinnedMeshRenderer.enabled != shouldRender)
				{
					_skinnedMeshRenderer.enabled = shouldRender;
				}
			}

			if (_systemGestureBehavior == SystemGestureBehavior.SwapMaterial)
			{
				if (_skinnedMeshRenderer != null)
				{
					if (ShouldUseSystemGestureMaterial && _systemGestureMaterial != null && _skinnedMeshRenderer.sharedMaterial != _systemGestureMaterial)
					{
						_skinnedMeshRenderer.sharedMaterial = _systemGestureMaterial;
					}
					else if (!ShouldUseSystemGestureMaterial && _originalMaterial != null && _skinnedMeshRenderer.sharedMaterial != _originalMaterial)
					{
						_skinnedMeshRenderer.sharedMaterial = _originalMaterial;
					}
				}
			}
		}
	}
}