/******************************************************************************
 * Copyright (C) Ultraleap, Inc. 2011-2021.                                   *
 *                                                                            *
 * Use subject to the terms of the Apache License 2.0 available at            *
 * http://www.apache.org/licenses/LICENSE-2.0, or another agreement           *
 * between Ultraleap and you, your company or other organization.             *
 ******************************************************************************/

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

namespace Leap.Unity.Interaction
{

    public class PhysicsCallbacks : MonoBehaviour
    {

        public static Action OnPrePhysics
        {
            get { return Provider._onPrePhysics; }
            set { Provider._onPrePhysics = value; }
        }

        public static Action OnPostPhysics
        {
            get { return Provider._onPostPhysics; }
            set { Provider._onPostPhysics = value; }
        }

        public static PhysicsCallbacks _instance;
        public static PhysicsCallbacks Provider
        {
            get
            {
                if (_instance == null)
                {
                    _instance = ConstructSingleton();
                }
                return _instance;
            }
        }

        private static PhysicsCallbacks ConstructSingleton()
        {
            GameObject parent = new GameObject("Physics Callbacks Provider");
            parent.transform.position = new Vector3(-10000F, -10000F, -10000F);

            GameObject trigger0 = new GameObject("OnPostPhysics Trigger 0");
            trigger0.transform.parent = parent.transform;
            trigger0.transform.localPosition = Vector3.zero;
            var body = trigger0.AddComponent<Rigidbody>();
            body.isKinematic = true;
            var box = trigger0.AddComponent<BoxCollider>();
            box.isTrigger = true;

            GameObject trigger1 = Instantiate<GameObject>(trigger0);
            trigger1.name = "OnPostPhysics Trigger 1";
            trigger1.transform.parent = parent.transform;
            trigger1.transform.localPosition = Vector3.zero;

            PhysicsCallbacks postPhysicsTrigger = trigger0.AddComponent<PhysicsCallbacks>();
            return postPhysicsTrigger;
        }

        private Action _onPrePhysics = () => { };
        private Action _onPostPhysics = () => { };

        void FixedUpdate()
        {
            _onPrePhysics();
        }

        void OnTriggerStay()
        {
            _onPostPhysics();
        }

    }

}