using UnityEngine;
using UnityEditor;
using System.Collections.Generic;
using System.IO;
using System.Reflection;
using System;
using UnityEditorInternal;

namespace XSToon3
{
    public class XSGradientEditor : EditorWindow
    {
        public List<int> gradients_index = new List<int>(new int[1] { 0 });
        public List<Gradient> gradients = new List<Gradient>(5);
        public Texture2D tex;

        private string finalFilePath;

        private bool isLinear = false;
        private bool manualMaterial = false;
        private enum Resolutions
        {
            Tiny64x8 = 64,
            Small128x8 = 128,
            Medium256x8 = 256,
            Large512x8 = 512
        }
        private Resolutions res = Resolutions.Tiny64x8;
        public static Material focusedMat;
        private Material oldFocusedMat;
        private Texture oldTexture;
        private string rampProperty = "_Ramp";
        private ReorderableList grad_index_reorderable;
        private bool reorder;
        private static GUIContent iconToolbarPlus;
        private static GUIContent iconToolbarMinus;
        private static GUIStyle preButton;
        private static GUIStyle buttonBackground;
        private bool changed;
        private int loadGradIndex;
        private XSMultiGradient xsmg;
        private Vector2 scrollPos;

        private bool dHelpText = false;
        //private bool dAdvanced = false;

        [MenuItem("Tools/Xiexe/XSToon/Gradient Editor")]
        static public void Init()
        {
            XSGradientEditor window = EditorWindow.GetWindow<XSGradientEditor>(false, "XSToon: Gradient Editor", true);
            window.minSize = new Vector2(450, 390);
        }

        public void OnGUI()
        {
            changed = false;
            if (focusedMat != null)
            {
                XSStyles.ShurikenHeader("Current Material: " + focusedMat.name);
            }
            else
            {
                XSStyles.ShurikenHeader("Current Material: None");
            }

            if (preButton == null)
            {
                iconToolbarPlus = EditorGUIUtility.IconContent("Toolbar Plus", "Add Gradient");
                iconToolbarMinus = EditorGUIUtility.IconContent("Toolbar Minus", "Remove Gradient");
                preButton = new GUIStyle("RL FooterButton");
                buttonBackground = new GUIStyle("RL Header");
            }

            if (gradients.Count == 0)
            {
                gradients.Add(new Gradient());
                gradients.Add(new Gradient());
                gradients.Add(new Gradient());
                gradients.Add(new Gradient());
                gradients.Add(new Gradient());
            }

            if (grad_index_reorderable == null)
            {
                makeReorderedList();
            }

            GUILayout.BeginHorizontal();
            GUILayout.FlexibleSpace();
            Rect r = EditorGUILayout.GetControlRect();
            float rightEdge = r.xMax;
            float leftEdge = rightEdge - 48f;
            r = new Rect(leftEdge, r.y, rightEdge - leftEdge, r.height);
            if (Event.current.type == EventType.Repaint) buttonBackground.Draw(r, false, false, false, false);
            leftEdge += 18f;
            EditorGUI.BeginDisabledGroup(gradients_index.Count == 5);
            bool addE = GUI.Button(new Rect(leftEdge + 4, r.y, 25, 13), iconToolbarPlus, preButton);
            EditorGUI.EndDisabledGroup();
            EditorGUI.BeginDisabledGroup(gradients_index.Count == 1);
            bool removeE = GUI.Button(new Rect(leftEdge - 19, r.y, 25, 13), iconToolbarMinus, preButton);
            EditorGUI.EndDisabledGroup();

            if (addE)
            {
                grad_index_reorderable.index++;
                int wat = 0;
                for (int i = 0; i < 5; i++)
                {
                    if (!gradients_index.Contains(i))
                    {
                        wat = i;
                        break;
                    }
                }
                gradients_index.Add(wat);
                changed = true;
            }
            if (removeE)
            {
                gradients_index.Remove(gradients_index[gradients_index.Count - 1]);
                grad_index_reorderable.index--;
                changed = true;
            }

            GUIStyle button = new GUIStyle(EditorStyles.miniButton);
            button.normal = !reorder ? EditorStyles.miniButton.normal : EditorStyles.miniButton.onNormal;
            if (GUILayout.Button(new GUIContent("Reorder", "Don't use Reorder if you want to undo a gradient change"), button, GUILayout.ExpandWidth(false)))
            {
                reorder = !reorder;
            }
            GUILayout.EndHorizontal();

            SerializedObject serializedObject = new SerializedObject(this);
            if (reorder)
            {
                grad_index_reorderable.DoLayoutList();
            }
            else
            {
                SerializedProperty colorGradients = serializedObject.FindProperty("gradients");
                if (colorGradients.arraySize == 5)
                {
                    for (int i = 0; i < gradients_index.Count; i++)
                    {
                        Rect _r = EditorGUILayout.GetControlRect();
                        _r.x += 16f;
                        _r.width -= 2f + 16f;
                        _r.height += 5f;
                        _r.y += 2f + (3f * i);
                        EditorGUI.PropertyField(_r, colorGradients.GetArrayElementAtIndex(gradients_index[i]), new GUIContent(""));
                    }
                    GUILayout.Space(Mathf.Lerp(9f, 24f, gradients_index.Count / 5f));
                }
            }
            if (serializedObject.ApplyModifiedProperties()) changed = true;

            if (oldFocusedMat != focusedMat)
            {
                changed = true;
                if (this.oldTexture != null)
                {
                    if (this.oldTexture == EditorGUIUtility.whiteTexture) this.oldTexture = null;
                    oldFocusedMat.SetTexture(rampProperty, this.oldTexture);
                    this.oldTexture = null;
                }
                oldFocusedMat = focusedMat;
            }

            Resolutions oldRes = res;
            res = (Resolutions)EditorGUILayout.EnumPopup("Resolution: ", res);
            if (oldRes != res) changed = true;

            int width = (int)res;
            int height = 30;
            if (gradients_index.Count == 1)
            {
                height = 8;
            }
            else
            {
                height = 150;
            }
            if (tex == null)
            {
                tex = new Texture2D(width, height, TextureFormat.RGBA32, false);
            }

            bool old_isLinear = isLinear;
            drawAdvancedOptions();
            if (old_isLinear != isLinear)
            {
                changed = true;
            }

            if (manualMaterial)
            {
                focusedMat = (Material)EditorGUILayout.ObjectField(new GUIContent("", ""), focusedMat, typeof(Material), true);
            }

            if (focusedMat != null)
            {
                if (focusedMat.HasProperty("_Ramp"))
                {
                    rampProperty = "_Ramp";
                }
                else
                {
                    rampProperty = EditorGUILayout.TextField("Ramp Property Name", rampProperty);
                    if (!focusedMat.HasProperty(rampProperty))
                    {
                        GUILayout.Label("Property not found!");
                    }
                }
            }

            if (changed)
            {
                updateTexture(width, height);
                if (focusedMat != null)
                {
                    if (focusedMat.HasProperty(rampProperty))
                    {
                        if (this.oldTexture == null)
                        {
                            if (focusedMat.GetTexture(rampProperty) == null)
                            {
                                this.oldTexture = EditorGUIUtility.whiteTexture;
                            }
                            else
                            {
                                this.oldTexture = focusedMat.GetTexture(rampProperty);
                            }
                        }
                        tex.wrapMode = TextureWrapMode.Clamp;
                        tex.Apply(false, false);
                        focusedMat.SetTexture(rampProperty, tex);
                    }
                }
            }

            XSStyles.Separator();
            drawMGInputOutput();


            if (GUILayout.Button("Save Ramp"))
            {
                finalFilePath = XSStyles.findAssetPath(finalFilePath);
                string path = EditorUtility.SaveFilePanel("Save Ramp as PNG", finalFilePath + "/Textures/Shadow Ramps/Generated", "gradient", "png");
                if (path.Length != 0)
                {
                    updateTexture(width, height);
                    bool success = GenTexture(tex, path);
                    if (success)
                    {
                        if (focusedMat != null)
                        {
                            string s = path.Substring(path.IndexOf("Assets"));
                            Texture ramp = AssetDatabase.LoadAssetAtPath<Texture>(s);
                            if (ramp != null)
                            {
                                focusedMat.SetTexture(rampProperty, ramp);
                                this.oldTexture = null;
                            }
                        }
                    }
                }
            }
            drawHelpText();
        }

        Gradient reflessGradient(Gradient old_grad)
        {
            Gradient grad = new Gradient();
            grad.SetKeys(old_grad.colorKeys, old_grad.alphaKeys);
            grad.mode = old_grad.mode;
            return grad;
        }

        List<int> reflessIndexes(List<int> old_indexes)
        {
            List<int> indexes = new List<int>();
            for (int i = 0; i < old_indexes.Count; i++)
            {
                indexes.Add(old_indexes[i]);
            }
            return indexes;
        }

        void makeReorderedList()
        {
            grad_index_reorderable = new ReorderableList(gradients_index, typeof(int), true, false, false, false);
            grad_index_reorderable.headerHeight = 0f;
            grad_index_reorderable.footerHeight = 0f;
            grad_index_reorderable.showDefaultBackground = true;

            grad_index_reorderable.drawElementCallback = (Rect rect, int index, bool isActive, bool isFocused) =>
            {
                if (gradients.Count == 5)
                {
                    Type editorGui = typeof(EditorGUI);
                    MethodInfo mi = editorGui.GetMethod("GradientField", BindingFlags.NonPublic | BindingFlags.Static, null, new Type[2] { typeof(Rect), typeof(Gradient) }, null);
                    mi.Invoke(this, new object[2] { rect, gradients[gradients_index[index]] });
                    if (Event.current.type == EventType.Repaint)
                    {
                        changed = true;
                    }
                }
            };

            grad_index_reorderable.onChangedCallback = (ReorderableList list) =>
            {
                changed = true;
            };
        }

        void OnDestroy()
        {
            if (focusedMat != null)
            {
                if (this.oldTexture != null)
                {
                    if (this.oldTexture == EditorGUIUtility.whiteTexture)
                    {
                        this.oldTexture = null;
                    }
                    focusedMat.SetTexture(rampProperty, this.oldTexture);
                    this.oldTexture = null;
                }
                focusedMat = null;
            }
        }

        void updateTexture(int width, int height)
        {
            tex = new Texture2D(width, height, TextureFormat.RGBA32, false);
            for (int y = 0; y < height; y++)
            {
                for (int x = 0; x < width; x++)
                {
                    if (gradients_index.Count != 1)
                    {
                        int gradNum = Mathf.FloorToInt(y / 30f);
                        gradNum = Mathf.Abs(gradNum - 5) - 1;
                        if (gradNum >= gradients_index.Count)
                        {
                            tex.SetPixel(x, y, Color.white);
                        }
                        else
                        {
                            if (gradients[gradients_index[gradNum]] != null)
                            {
                                Color grad_col = gradients[gradients_index[gradNum]].Evaluate((float)x / (float)width);
                                tex.SetPixel(x, y, isLinear ? grad_col.gamma : grad_col);
                            }
                            else
                            {
                                tex.SetPixel(x, y, Color.white);
                            }
                        }
                    }
                    else
                    {
                        Color grad_col = gradients[gradients_index[0]].Evaluate((float)x / (float)width);
                        tex.SetPixel(x, y, isLinear ? grad_col.gamma : grad_col);
                    }
                }
            }
        }

        bool GenTexture(Texture2D tex, string path)
        {
            var pngData = tex.EncodeToPNG();
            if (pngData != null)
            {
                File.WriteAllBytes(path, pngData);
                AssetDatabase.Refresh();
                return ChangeImportSettings(path);
            }
            return false;
        }

        bool ChangeImportSettings(string path)
        {

            string s = path.Substring(path.LastIndexOf("Assets"));
            TextureImporter texture = (TextureImporter)TextureImporter.GetAtPath(s);
            if (texture != null)
            {
                texture.wrapMode = TextureWrapMode.Clamp;
                texture.maxTextureSize = 512;
                texture.mipmapEnabled = false;
                texture.textureCompression = TextureImporterCompression.Uncompressed;

                // texture.sRGBTexture = !isLinear; // We already do the conversion in tex.SetPixel

                texture.SaveAndReimport();
                AssetDatabase.Refresh();
                return true;

                // shadowRamp = (Texture)Resources.Load(path);
                // Debug.LogWarning(shadowRamp.ToString());
            }
            else
            {
                Debug.Log("Asset Path is Null, can't set to Clamped.\n You'll need to do it manually.");
            }
            return false;
        }

        void drawMGInputOutput()
        {
            GUILayout.BeginHorizontal();
            XSMultiGradient old_xsmg = xsmg;
            xsmg = (XSMultiGradient)EditorGUILayout.ObjectField("MultiGradient Preset", xsmg, typeof(XSMultiGradient), false, null);
            if (xsmg != old_xsmg)
            {
                if (xsmg != null)
                {
                    this.gradients = xsmg.gradients;
                    this.gradients_index = xsmg.order;
                    makeReorderedList();
                }
                else
                {
                    List<Gradient> new_Grads = new List<Gradient>();
                    for (int i = 0; i < this.gradients.Count; i++)
                    {
                        new_Grads.Add(reflessGradient(this.gradients[i]));
                    }
                    this.gradients = new_Grads;
                    this.gradients_index = reflessIndexes(this.gradients_index);
                    makeReorderedList();
                }
                changed = true;
            }

            if (GUILayout.Button("Save New", EditorStyles.miniButton, GUILayout.ExpandWidth(false)))
            {
                finalFilePath = XSStyles.findAssetPath(finalFilePath);
                string path = EditorUtility.SaveFilePanel("Save MultiGradient", (finalFilePath + "/Textures/Shadow Ramps/MGPresets"), "MultiGradient", "asset");
                if (path.Length != 0)
                {
                    path = path.Substring(Application.dataPath.Length - "Assets".Length);
                    XSMultiGradient _xsmg = ScriptableObject.CreateInstance<XSMultiGradient>();
                    _xsmg.uniqueName = Path.GetFileNameWithoutExtension(path);
                    foreach (Gradient grad in gradients)
                    {
                        _xsmg.gradients.Add(reflessGradient(grad));
                    }
                    _xsmg.order.AddRange(gradients_index.ToArray());
                    xsmg = _xsmg;
                    AssetDatabase.CreateAsset(_xsmg, path);
                    this.gradients = xsmg.gradients;
                    this.gradients_index = xsmg.order;
                    makeReorderedList();
                    AssetDatabase.SaveAssets();
                }
            }
            GUILayout.EndHorizontal();
        }

        void drawAdvancedOptions()
        {
            GUILayout.BeginHorizontal();
            isLinear = GUILayout.Toggle(isLinear, "Make Linear Texture");
            manualMaterial = GUILayout.Toggle(manualMaterial, "Manual Material");
            GUILayout.EndHorizontal();
        }

        void drawHelpText()
        {
            XSStyles.Separator();
            dHelpText = XSStyles.ShurikenFoldout("Information", dHelpText);
            if(dHelpText)
            {
                scrollPos = EditorGUILayout.BeginScrollView(scrollPos);
                    XSStyles.HelpBox("You can use this to create a custom shadow ramp in realtime. \nIf you do not save, the ramp will be reverted back to what it was previously. \n\n - Click the Gradient box. \n - Choose resolution of the texture. \n - Save.", MessageType.Info);
                    XSStyles.HelpBox("Ramp textures support up to 5 ramps in one texture. That means you can have up to 5 ramps on a single material. You will need to author a ramp mask to choose which ramp to sample from. \n\nA texture that is fully black would sample from the bottom ramp, a texture that is fully white would sample from the top ramp, and a texture that is half gray would sample from the middle ramp. \n\n A quick tip would be that you can sample from each of the 5 ramps with 0, 0.25, 0.5, 0.75, and 1 on the texture. \n\nThe order of the gradients on the UI is the order that they will be on the texture.", MessageType.Info);
                EditorGUILayout.EndScrollView();
            }
        }
    }
}