using UnityEngine;
using UnityEditor;

namespace UDE_HAND_INTERACTION
{
    [CustomEditor(typeof(InteractableSurface))]
    public class InteractableSurfaceEditor : Editor
    {
        private const int NUM_SEGMENTS = 10;
        private const float FADE_DISTANCE = 1f;
        private static readonly Color Color = new Color(0f, 1f, 1f, 0.1f);
        private static float Interval => FADE_DISTANCE / NUM_SEGMENTS;

        private InteractableSurface surface;

        private void OnEnable()
        {
            surface = target as InteractableSurface;
        }

        public void OnSceneGUI()
        {
            Draw(surface);
        }

        public override void OnInspectorGUI()
        {
            DrawDefaultInspector();
            switch((int)surface.surfaceType)
            {
                case 0:
                    //surface.Position = EditorGUILayout.Vector3Field("Position", surface.Position);
                    surface._width = EditorGUILayout.FloatField("Width", surface._width);
                    surface._height = EditorGUILayout.FloatField("Height", surface._height);
                    break;
                case 1:
                    surface._radius = EditorGUILayout.FloatField("Radius", surface._radius);
                    break;
                case 2:
                    break;
            }
        }

        public static void Draw(InteractableSurface surface)
        {
            Vector3 origin = surface.transform.position;

            if (SceneView.lastActiveSceneView?.camera != null)
            {
                Transform camTransform = SceneView.lastActiveSceneView.camera.transform;
                if (surface.ClosestSurfacePoint(camTransform.position, out SurfaceHit hit, 0))
                {
                    Vector3 hitDelta = PoseManager.Delta(surface.transform, new Pose(hit.Point, surface.transform.rotation)).position;
                    hitDelta.x = Mathf.RoundToInt(hitDelta.x / Interval) * Interval;
                    hitDelta.y = Mathf.RoundToInt(hitDelta.y / Interval) * Interval;
                    hitDelta.z = 0f;
                    origin = PoseManager.Multiply(surface.transform.GetPose(), new Pose(hitDelta, Quaternion.identity)).position;
                }
            }

            if((int)surface.surfaceType == 1)
            {
                Handles.color = Color.green;
                Vector3 ArcDir = Quaternion.AngleAxis(0, surface.Normal) * Vector3.ProjectOnPlane(origin, surface.Normal).normalized;
                Handles.DrawWireArc(origin, surface.Normal, ArcDir, 360, surface._radius);
                for (int i = 0; i < 12; ++i)
                {
                    Vector3 Cur_dir = Quaternion.AngleAxis(i * 30, surface.Normal) * ArcDir;
                    Handles.DrawLine(origin, origin + Cur_dir * surface._radius);
                }
            }
            else if((int)surface.surfaceType == 0)
            {
                if (!surface.GetLocalBounds(surface.transform, out Bounds localBounds))
                {
                    return;
                }

                Handles.color = Color.green;
                Handles.matrix = surface.transform.localToWorldMatrix;
                Handles.DrawWireCube(localBounds.center, localBounds.size);
                Vector3 BondSizeX = new(localBounds.size.x / 5, 0, 0);
                Vector3 BondSizeY = new(0, localBounds.size.y / 5, 0);
                for (int i = 0; i < 5; ++i)
                {
                    Handles.DrawLine(localBounds.center - (localBounds.size / 2) + i * BondSizeY, localBounds.center + (localBounds.size / 2) - i * BondSizeX);
                    Handles.DrawLine(localBounds.center - (localBounds.size / 2) + i * BondSizeX, localBounds.center + (localBounds.size / 2) - i * BondSizeY);
                }
            }
            else
            {
                DrawLines(origin, surface.Normal, surface.transform.up, Color);
                DrawLines(origin, surface.Normal, -surface.transform.up, Color);
                DrawLines(origin, surface.Normal, surface.transform.right, Color);
                DrawLines(origin, surface.Normal, -surface.transform.right, Color);
            }
        }

        private static void DrawLines(in Vector3 origin, in Vector3 normal, in Vector3 direction, in Color baseColor)
        {
            Color prevColor = Handles.color;
            Color color = baseColor;
            Vector3 offsetOrigin = origin;

            for (int i = 0; i < NUM_SEGMENTS; ++i)
            {
                Handles.color = color;

                Vector3 cross = Vector3.Cross(normal, direction).normalized;
                float interval = Interval;

                for (int j = -NUM_SEGMENTS; j < NUM_SEGMENTS; ++j)
                {
                    float horizStart = interval * j;
                    float horizEnd = horizStart + interval;

                    Vector3 start = offsetOrigin + cross * horizStart;
                    Vector3 end = offsetOrigin + cross * horizEnd;

                    color.a = 1f - Mathf.Abs((float)j / NUM_SEGMENTS);
                    color.a *= 1f - ((float)i / NUM_SEGMENTS);
                    color.a *= color.a;

                    Handles.color = color;
                    Handles.DrawLine(start, end);
                }

                offsetOrigin += direction * interval;
                color = baseColor;
            }

            Handles.color = prevColor;
        }

    }
}