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

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;
using UnityEngine;
using UnityEngine.Events;

namespace OculusSampleFramework
{
	/// <summary>
	/// Interface for all objects interacted with in example code.
	/// </summary>
	public abstract class Interactable : MonoBehaviour
	{
		protected ColliderZone _proximityZoneCollider = null;
		protected ColliderZone _contactZoneCollider = null;
		protected ColliderZone _actionZoneCollider = null;

		// Collider that indicates "am I close?"
		public ColliderZone ProximityCollider
		{
			get
			{
				return _proximityZoneCollider;
			}
		}

		// Collider that indicates that contact has been made.
		public ColliderZone ContactCollider
		{
			get
			{
				return _contactZoneCollider;
			}
		}

		// Indicates interactable has been activated. Like when
		// a button goes "click" and something interesting happens.
		public ColliderZone ActionCollider
		{
			get
			{
				return _actionZoneCollider;
			}
		}

		// What kinds of tools works with this interactable?
		public virtual int ValidToolTagsMask
		{
			get
			{
				return (int)InteractableToolTags.All;
			}
		}

		// The following events tell you if a tool is in a zone, which
		// might *not* mean the button is in the related zone state. This can happen
		// if a tool is in the contact zone but the interactable won't go into
		// the contact state if bad interactions (i.e. incorrect button presses)
		// are filtered out.

		public event Action<ColliderZoneArgs> ProximityZoneEvent;

		protected virtual void OnProximityZoneEvent(ColliderZoneArgs args)
		{
			if (ProximityZoneEvent != null)
			{
				ProximityZoneEvent.Invoke(args);
			}
		}

		public event Action<ColliderZoneArgs> ContactZoneEvent;

		protected virtual void OnContactZoneEvent(ColliderZoneArgs args)
		{
			if (ContactZoneEvent != null)
			{
				ContactZoneEvent.Invoke(args);
			}
		}

		public event Action<ColliderZoneArgs> ActionZoneEvent;

		protected virtual void OnActionZoneEvent(ColliderZoneArgs args)
		{
			if (ActionZoneEvent != null)
			{
				ActionZoneEvent.Invoke(args);
			}
		}

		public abstract void UpdateCollisionDepth(InteractableTool interactableTool,
		  InteractableCollisionDepth oldCollisionDepth, InteractableCollisionDepth newCollisionDepth);

		[Serializable]
		public class InteractableStateArgsEvent : UnityEvent<InteractableStateArgs>
		{
		}

		public InteractableStateArgsEvent InteractableStateChanged;

		protected virtual void Awake()
		{
			InteractableRegistry.RegisterInteractable(this);
		}

		protected virtual void OnDestroy()
		{
			InteractableRegistry.UnregisterInteractable(this);
		}
	}

	/// <summary>
	/// Depth of collision, in order of "furthest" to "closest"
	/// </summary>
	public enum InteractableCollisionDepth
	{
		None = 0,
		Proximity,
		Contact,
		Action,
	}

	public enum InteractableState
	{
		Default = 0,
		ProximityState, // in proximity -- close enough
		ContactState, // contact has been made
		ActionState, // interactable activates
	}

	public class InteractableStateArgs : EventArgs
	{
		public readonly Interactable Interactable;
		public readonly InteractableTool Tool;
		public readonly InteractableState OldInteractableState;
		public readonly InteractableState NewInteractableState;
		public readonly ColliderZoneArgs ColliderArgs;

		public InteractableStateArgs(Interactable interactable, InteractableTool tool,
		  InteractableState newInteractableState, InteractableState oldState,
		  ColliderZoneArgs colliderArgs)
		{
			Interactable = interactable;
			Tool = tool;
			NewInteractableState = newInteractableState;
			OldInteractableState = oldState;
			ColliderArgs = colliderArgs;
		}
	}
}