/******************************************************************************
 * 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.Collections;
using System.Collections.Generic;
using UnityEditor;
using UnityEngine;

namespace Leap.Unity.Attachments
{

    [CustomEditor(typeof(AttachmentHands))]
    public class AttachmentHandsEditor : CustomEditorBase<AttachmentHands>
    {

        private Texture _handTex;
        private Rect _handTexRect;

        protected override void OnEnable()
        {
            base.OnEnable();

            _handTex = Resources.Load<Texture2D>("HandTex");

            this.specifyCustomDrawer("_attachmentPoints", drawAttachmentPointsEditor);
        }

        private void drawAttachmentPointsEditor(SerializedProperty property)
        {

            // Set up the draw rect space based on the image and available editor space.

            EditorGUILayout.Space();
            EditorGUILayout.LabelField("Attachment Transforms", EditorStyles.boldLabel);

            // Determine whether the target object is a prefab. AttachmentPoints cannot be edited on prefabs.
            var isTargetPrefab = Utils.IsObjectPartOfPrefabAsset(target.gameObject);

            if (isTargetPrefab)
            {
                EditorGUILayout.HelpBox("Drag the prefab into the scene to make changes to attachment points.", MessageType.Info, true);
            }

            _handTexRect = EditorGUILayout.BeginVertical(GUILayout.MinWidth(EditorGUIUtility.currentViewWidth),
                                                         GUILayout.MinHeight(EditorGUIUtility.currentViewWidth * (_handTex.height / (float)_handTex.width)),
                                                         GUILayout.MaxWidth(_handTex.width),
                                                         GUILayout.MaxHeight(_handTex.height));

            Rect imageContainerRect = _handTexRect; imageContainerRect.width = EditorGUIUtility.currentViewWidth - 30F;
            EditorGUI.DrawRect(imageContainerRect, new Color(0.2F, 0.2F, 0.2F));
            imageContainerRect.x += 1; imageContainerRect.y += 1; imageContainerRect.width -= 2; imageContainerRect.height -= 2;
            EditorGUI.DrawRect(imageContainerRect, new Color(0.6F, 0.6F, 0.6F));
            imageContainerRect.x += 1; imageContainerRect.y += 1; imageContainerRect.width -= 2; imageContainerRect.height -= 2;
            EditorGUI.DrawRect(imageContainerRect, new Color(0.2F, 0.2F, 0.2F));

            _handTexRect = new Rect(_handTexRect.x + (imageContainerRect.center.x - _handTexRect.center.x),
                                    _handTexRect.y,
                                    _handTexRect.width,
                                    _handTexRect.height);
            EditorGUI.DrawTextureTransparent(_handTexRect, _handTex);
            EditorGUILayout.Space();


            // Draw the toggles for the attachment points.

            EditorGUI.BeginDisabledGroup(isTargetPrefab);

            makeAttachmentPointsToggle("Palm", new Vector2(0.100F, 0.160F));
            makeAttachmentPointsToggle("Wrist", new Vector2(0.080F, 0.430F));

            makeAttachmentPointsToggle("ThumbProximalJoint", new Vector2(-0.190F, 0.260F));
            makeAttachmentPointsToggle("ThumbDistalJoint", new Vector2(-0.310F, 0.170F));
            makeAttachmentPointsToggle("ThumbTip", new Vector2(-0.390F, 0.110F));

            makeAttachmentPointsToggle("IndexKnuckle", new Vector2(-0.040F, -0.040F));
            makeAttachmentPointsToggle("IndexMiddleJoint", new Vector2(-0.060F, -0.170F));
            makeAttachmentPointsToggle("IndexDistalJoint", new Vector2(-0.075F, -0.280F));
            makeAttachmentPointsToggle("IndexTip", new Vector2(-0.080F, -0.380F));

            makeAttachmentPointsToggle("MiddleKnuckle", new Vector2(0.080F, -0.050F));
            makeAttachmentPointsToggle("MiddleMiddleJoint", new Vector2(0.080F, -0.190F));
            makeAttachmentPointsToggle("MiddleDistalJoint", new Vector2(0.080F, -0.310F));
            makeAttachmentPointsToggle("MiddleTip", new Vector2(0.090F, -0.420F));

            makeAttachmentPointsToggle("RingKnuckle", new Vector2(0.195F, -0.020F));
            makeAttachmentPointsToggle("RingMiddleJoint", new Vector2(0.220F, -0.150F));
            makeAttachmentPointsToggle("RingDistalJoint", new Vector2(0.230F, -0.270F));
            makeAttachmentPointsToggle("RingTip", new Vector2(0.245F, -0.380F));

            makeAttachmentPointsToggle("PinkyKnuckle", new Vector2(0.295F, 0.040F));
            makeAttachmentPointsToggle("PinkyMiddleJoint", new Vector2(0.340F, -0.050F));
            makeAttachmentPointsToggle("PinkyDistalJoint", new Vector2(0.380F, -0.130F));
            makeAttachmentPointsToggle("PinkyTip", new Vector2(0.410F, -0.210F));

            EditorGUI.EndDisabledGroup();

            EditorGUILayout.EndVertical();
        }

        private void makeAttachmentPointsToggle(string attachmentFlagName, Vector2 offCenterPosImgSpace)
        {
            AttachmentPointFlags attachmentPoints = target.attachmentPoints;

            AttachmentPointFlags flag = (AttachmentPointFlags)System.Enum.Parse(typeof(AttachmentPointFlags), attachmentFlagName, true);

            if (EditorGUI.Toggle(makeToggleRect(_handTexRect.center
                                                + new Vector2(offCenterPosImgSpace.x * _handTexRect.width,
                                                              offCenterPosImgSpace.y * _handTexRect.height)),
                                 (attachmentPoints & flag) == flag))
            {

                target.attachmentPoints = attachmentPoints | flag; // Set flag bit to 1.
            }
            else
            {
                if (!wouldFlagDeletionDestroyData(target, flag)
                    || EditorUtility.DisplayDialog("Delete " + flag + " Attachment Point?",
                                                   "Deleting the " + flag + " attachment point will destroy "
                                                 + "its GameObject and any of its non-Attachment-Point children, "
                                                 + "and will remove any components attached to it.",
                                                   "Delete " + flag + " Attachment Point", "Cancel"))
                {

                    target.attachmentPoints = attachmentPoints & (~flag); // Set flag bit to 0.
                }
            }
        }

        private const float TOGGLE_SIZE = 15.0F;
        private Rect makeToggleRect(Vector2 centerPos)
        {
            return new Rect(centerPos.x - TOGGLE_SIZE / 2F, centerPos.y - TOGGLE_SIZE / 2F, TOGGLE_SIZE, TOGGLE_SIZE);
        }

        private static bool wouldFlagDeletionDestroyData(AttachmentHands target, AttachmentPointFlags flag)
        {
            if (target.attachmentHands == null) return false;

            foreach (var attachmentHand in target.attachmentHands)
            {
                var point = attachmentHand.GetBehaviourForPoint(flag);

                if (point == null) return false;
                else
                {
                    // Data will be destroyed if this AttachmentPointBehaviour's Transform contains any children
                    // that are not themselves AttachmentPointBehaviours.
                    foreach (var child in point.transform.GetChildren())
                    {
                        if (child.GetComponent<AttachmentPointBehaviour>() == null) return true;
                    }

                    // Data will be destroyed if this AttachmentPointBehaviour contains any components
                    // that aren't constructed automatically.
                    foreach (var component in point.gameObject.GetComponents<Component>())
                    {
                        if (component is Transform) continue;
                        if (component is AttachmentPointBehaviour) continue;

                        return true;
                    }
                }
            }
            return false;
        }

    }

}