/******************************************************************************
 * 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 Leap.Unity.Attributes;
using Leap.Unity.RuntimeGizmos;
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

namespace Leap.Unity.Animation.Examples
{

    [ExecuteInEditMode]
    [AddComponentMenu("")]
    public class TransformPoseSpline : MonoBehaviour, IRuntimeGizmoComponent
    {

        [QuickButton("Spawn Default", "spawnDefaultSource0")]
        public Transform pose0Source;

        [QuickButton("Spawn Default", "spawnDefaultSource1")]
        public Transform pose1Source;

        [Header("Debug View")]
        [Range(0f, 1f)]
        public float renderPoseAtT = 0f;

        private HermitePoseSpline? maybePoseSpline;

        private void Update()
        {
            if (pose0Source != null && pose1Source != null)
            {

                var pose0 = pose0Source.ToPose();
                var pose1 = pose1Source.ToPose();

                var movement0 = Movement.identity;
                if (pose0Source.childCount > 0)
                {
                    var pose0SourceChild = pose0Source.GetChild(0);
                    movement0 = new Movement(pose0, pose0SourceChild.ToPose(), 0.1f);
                }

                var movement1 = Movement.identity;
                if (pose1Source.childCount > 0)
                {
                    var pose1SourceChild = pose1Source.GetChild(0);
                    movement1 = new Movement(pose1, pose1SourceChild.ToPose(), 0.1f);
                }

                maybePoseSpline = new HermitePoseSpline(pose0, pose1,
                                                        movement0, movement1);
            }
        }

        private void spawnDefaultSource0() { spawnDefaultSource(false); }
        private void spawnDefaultSource1() { spawnDefaultSource(true); }
        private void spawnDefaultSource(bool isSecondSource)
        {
            var newPoseSourceObj = new GameObject("Pose Source " + (isSecondSource ? 1 : 0));
            newPoseSourceObj.transform.parent = this.transform;
            newPoseSourceObj.transform.ResetLocalTransform();
            newPoseSourceObj.transform.localPosition += Vector3.right * 0.2f
                                                        * (isSecondSource ? 1 : -1);
            if (isSecondSource) { pose1Source = newPoseSourceObj.transform; }
            else { pose0Source = newPoseSourceObj.transform; }
        }

        public void OnDrawRuntimeGizmos(RuntimeGizmoDrawer drawer)
        {
            if (maybePoseSpline.HasValue)
            {
                var spline = maybePoseSpline.Value;

                drawer.color = LeapColor.brown.WithAlpha(0.4f);

                Vector3? prevPos = null;
                int numSteps = 32;
                int drawPosePer = 8, counter = 0;
                float tStep = 1f / numSteps;
                for (float t = 0f; t <= 1f; t += tStep)
                {
                    var pose = spline.PoseAt(t);

                    if (counter % drawPosePer == 0)
                    {
                        drawer.DrawPose(pose, 0.02f);
                    }

                    if (prevPos.HasValue)
                    {
                        drawer.DrawLine(prevPos.Value, pose.position);
                    }

                    prevPos = pose.position;
                    counter++;
                }

                var renderPose = spline.PoseAt(renderPoseAtT);
                var len = 0.06f;
                var thick = 0.01f;
                drawer.PushMatrix();
                drawer.matrix = Matrix4x4.TRS(renderPose.position, renderPose.rotation, Vector3.one);
                drawer.color = Color.red;
                drawer.DrawCube(Vector3.right * ((len / 2f) + (thick / 2f)), new Vector3(len, thick, thick));
                drawer.color = Color.green;
                drawer.DrawCube(Vector3.up * ((len / 2f) + (thick / 2f)), new Vector3(thick, len, thick));
                drawer.color = Color.blue;
                drawer.DrawCube(Vector3.forward * ((len / 2f) + (thick / 2f)), new Vector3(thick, thick, len));
            }
        }
    }

}