﻿/*
MIT License

Copyright(c) 2019 Mitchel Thompson
www.angryarugula.com

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/

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

namespace Arugula
{
    [CustomEditor(typeof(MeshSlicer))]
    public class MeshSlicerEditor : Editor
    {
        static MeshSlicerEditor()
        {
            Undo.undoRedoPerformed += HandleUndoRedo;
        }

        static RectTransform helper;
        static Color fill = new Color(1, 0.815f, 0, 0.05f);
        static Color outline = new Color(1, 0.815f, 0, 0.5f);
        static Color hint = new Color(1, 0.815f, 0, 0.25f);
        static Color ghost = new Color(0, 0, 0, 0.3f);
        static bool adjustOffsets = false;

        MeshSlicer slicer;
        Transform root;
        private void OnEnable()
        {
            if (helper == null)
            {
                GameObject go = new GameObject("TempTransform");
                go.hideFlags = HideFlags.HideAndDontSave;
                helper = go.AddComponent<RectTransform>();

            }

            slicer = (MeshSlicer)target;
            root = slicer.transform;

            if (slicer.baseMesh == null)
            {
                if (slicer.GetComponent<MeshFilter>() != null)
                {
                    var m = slicer.GetComponent<MeshFilter>().sharedMesh;
                    string assetPath = AssetDatabase.GetAssetPath(m);
                    if (assetPath != "" && assetPath != null)
                    {
                        slicer.baseMesh = m;
                        slicer.Init(true);
                    }
                    else
                    {
                        Debug.LogWarning("baseMesh must not be a mesh instance", slicer);
                        EditorGUIUtility.PingObject(slicer.gameObject);
                    }
                }
            }


        }

        static void HandleUndoRedo()
        {
            MeshSlicer[] slicers = FindObjectsOfType<MeshSlicer>();
            foreach (var s in slicers)
                s.UpdateMesh();
        }

        public override void OnInspectorGUI()
        {
            if (slicer.baseMesh != null)
            {
                if (slicer.slices.Count > 0)
                {
                    if (adjustOffsets)
                    {
                        if (GUILayout.Button("Done", GUILayout.Height(32)))
                        {
                            adjustOffsets = false;
                            slicer.drawBaseMesh = false;
                            SceneView.RepaintAll();
                        }

                    }
                    else
                    {
                        if (GUILayout.Button("Edit", GUILayout.Height(32)))
                        {
                            slicer.drawBaseMesh = true;
                            adjustOffsets = true;
                            SceneView.RepaintAll();
                        }

                    }

                    GUILayout.BeginHorizontal();
                    if (GUILayout.Button("Update Mesh"))
                        slicer.UpdateMesh();
                    if (GUILayout.Button("Reset"))
                    {
                        foreach (var s in slicer.slices)
                            s.shift = 0;
                        slicer.UpdateMesh();
                    }

                    if (GUILayout.Button("Clear"))
                    {
                        slicer.slices.Clear();
                        slicer.UpdateMesh();
                    }


                    GUILayout.EndHorizontal();
                }
                else
                {
                    GUILayout.BeginHorizontal();
                    if (GUILayout.Button("XZ"))
                        slicer.CreateSlices(true, false, true);
                    if (GUILayout.Button("XY"))
                        slicer.CreateSlices(true, true, false);
                    if (GUILayout.Button("YZ"))
                        slicer.CreateSlices(false, true, true);
                    if (GUILayout.Button("XYZ"))
                        slicer.CreateSlices(true, true, true);

                    GUILayout.EndHorizontal();
                }

            }



            EditorGUI.BeginChangeCheck();
            base.OnInspectorGUI();
            if (EditorGUI.EndChangeCheck())
                slicer.UpdateMesh();
        }

        private void OnSceneGUI()
        {
            if (slicer.baseMesh == null)
                return;

            Handles.DrawWireCube(root.TransformPoint(slicer.baseMesh.bounds.center), HandleUtility.GetHandleSize(root.position) * 0.075f * Vector3.one);

            EditorGUI.BeginChangeCheck();

            Undo.RecordObject(slicer, "MeshSlicer");
            foreach (var s in slicer.slices)
            {
                if (adjustOffsets)
                    Offset(s);
                else
                {
                    Shift(s);
                }
            }

            if (EditorGUI.EndChangeCheck())
            {
                serializedObject.ApplyModifiedProperties();
                slicer.UpdateMesh();
            }
        }

        void Offset(MeshSlicer.Slice s)
        {
            Vector3 origin = root.TransformPoint(slicer.baseMesh.bounds.center);
            Vector3 position = root.TransformPoint(slicer.baseMesh.bounds.center + (s.normal * s.offset));

            Vector3 startPosition = origin + root.TransformPoint(s.normal * s.offset);

            Quaternion rot = Quaternion.LookRotation(root.TransformDirection(s.normal));

            Vector3[] points = new Vector3[4];
            helper.position = slicer.baseMesh.bounds.center + (s.normal * s.offset);
            helper.rotation = Quaternion.LookRotation(s.normal);
            helper.localScale = Vector3.one;
            //Vector3 hs = Vector3.Scale(slicer.baseMesh.bounds.size, root.lossyScale);
            Vector3 hs = slicer.baseMesh.bounds.size;

            float[] comps = { Mathf.Abs(s.normal.x), Mathf.Abs(s.normal.y), Mathf.Abs(s.normal.z) };
            int mi = comps.MaxIndex();

            switch (mi)
            {
                case 0:
                    helper.sizeDelta = new Vector2(hs.z, hs.y);
                    break;
                case 1:
                    helper.sizeDelta = new Vector2(hs.x, hs.z);
                    break;
                case 2:
                    helper.sizeDelta = new Vector2(hs.x, hs.y);
                    break;
            }

            helper.GetWorldCorners(points);
            //helper.GetWorldCorners(points);

            for (int i = 0; i < points.Length; i++)
                points[i] = root.TransformPoint(points[i]);

            Handles.color = fill;
            Handles.DrawLine(root.position, position);

            Handles.color = Color.white;
            Handles.Label(position, s.name);

            Handles.DrawSolidRectangleWithOutline(points, fill, outline);
            Handles.color = outline;
            Vector3 result = Handles.Slider(position, rot * Vector3.forward, 0.05f, Handles.DotHandleCap, 0);
            Vector3 delta = root.InverseTransformPoint(result) - root.InverseTransformPoint(origin);
            Plane p = new Plane(s.normal, 0);
            float x = delta.magnitude * (p.GetSide(delta) ? 1 : -1);
            if (!Mathf.Approximately(x, s.offset))
                s.offset = x;
        }

        void Shift(MeshSlicer.Slice s)
        {
            Vector3 origin = root.TransformPoint(slicer.baseMesh.bounds.center);
            Vector3 position = root.TransformPoint(slicer.baseMesh.bounds.center + (s.normal * (s.shift + s.offset)));
            Vector3 startPosition = root.TransformPoint(slicer.baseMesh.bounds.center + (s.normal * s.offset));

            Quaternion rot = root.rotation * Quaternion.FromToRotation(Vector3.forward, s.normal);
            Handles.color = hint;
            Handles.DrawLine(origin, position);

            if (s.link >= 0 && s.link < slicer.slices.Count)
            {
                Handles.color = ghost;
                Handles.DotHandleCap(0, position, Quaternion.identity, HandleUtility.GetHandleSize(position) * 0.05f, EventType.Repaint);
            }
            else
            {
                Handles.color = Color.white;
                Handles.Label(position, s.name);

                Handles.color = outline;
                Vector3 result = Handles.Slider(position, rot * Vector3.forward, HandleUtility.GetHandleSize(position) * 0.05f, Handles.DotHandleCap, 0);
                Vector3 delta = root.InverseTransformPoint(result) - root.InverseTransformPoint(startPosition);
                Plane p = new Plane(s.normal, 0);
                float x = delta.magnitude * (p.GetSide(delta) ? 1 : -1);

                if (!Mathf.Approximately(x, s.shift))
                    s.shift = x;
            }

        }
    }
}