/************************************************************************************

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

See SampleFramework license.txt for license terms.  Unless required by applicable law 
or agreed to in writing, the sample code is provided “AS IS” WITHOUT WARRANTIES OR 
CONDITIONS OF ANY KIND, either express or implied.  See the license for specific 
language governing permissions and limitations under the license.

************************************************************************************/

using System.Collections.Generic;
using UnityEngine;

namespace OculusSampleFramework
{
	/// <summary>
	/// Allows a bone to keep track of interactables that it has touched. This information
	/// can be used by a tool.
	/// </summary>
	public class BoneCapsuleTriggerLogic : MonoBehaviour
	{
		public InteractableToolTags ToolTags;

		public HashSet<ColliderZone> CollidersTouchingUs = new HashSet<ColliderZone>();
		private List<ColliderZone> _elementsToCleanUp = new List<ColliderZone>();

		/// <summary>
		/// If we get disabled, clear our colliders. Otherwise, on trigger exit may not get called.
		/// </summary>
		private void OnDisable()
		{
			CollidersTouchingUs.Clear();
		}

		private void Update()
		{
			CleanUpDeadColliders();
		}

		private void OnTriggerEnter(Collider other)
		{
			var triggerZone = other.GetComponent<ButtonTriggerZone>();
			if (triggerZone != null && (triggerZone.ParentInteractable.ValidToolTagsMask & (int)ToolTags) != 0)
			{
				CollidersTouchingUs.Add(triggerZone);
			}
		}

		private void OnTriggerExit(Collider other)
		{
			var triggerZone = other.GetComponent<ButtonTriggerZone>();
			if (triggerZone != null && (triggerZone.ParentInteractable.ValidToolTagsMask & (int)ToolTags) != 0)
			{
				CollidersTouchingUs.Remove(triggerZone);
			}
		}

		/// <summary>
		/// Sometimes colliders get disabled and trigger exit doesn't get called.
		/// Take care of that edge case.
		/// </summary>
		private void CleanUpDeadColliders()
		{
			_elementsToCleanUp.Clear();
			foreach (ColliderZone colliderTouching in CollidersTouchingUs)
			{
				if (!colliderTouching.Collider.gameObject.activeInHierarchy)
				{
					_elementsToCleanUp.Add(colliderTouching);
				}
			}

			foreach (ColliderZone colliderZone in _elementsToCleanUp)
			{
				CollidersTouchingUs.Remove(colliderZone);
			}
		}
	}
}