#if UNITY_EDITOR
using DCFApixels.DragonECS.Unity.Internal;
using System;
using System.Collections.Generic;
using System.Reflection;
using Unity.Collections.LowLevel.Unsafe;
using UnityEditor;
using UnityEngine;
using Color = UnityEngine.Color;
using UnityComponent = UnityEngine.Component;
using UnityObject = UnityEngine.Object;


namespace DCFApixels.DragonECS.Unity.Editors.X
{
    internal class RuntimeComponentsDrawer
    {
        private static readonly BindingFlags fieldFlags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic;
        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
        private static void ResetRuntimeComponentReflectionCache()
        {
            RefEditorWrapper.ResetStaticState();
            foreach (var item in _runtimeComponentReflectionCaches)
            {
                item.Value.ResetWrappers();
            }
            //_runtimeComponentReflectionCaches.Clear();
        }
        private const int RuntimeComponentsMaxDepth = 2;
        private static RuntimeComponentsDrawer[] _drawers;
        private static int _runtimeComponentsDepth = 2;
        static RuntimeComponentsDrawer()
        {
            _drawers = new RuntimeComponentsDrawer[RuntimeComponentsMaxDepth + 1];
            _drawers[0] = new RuntimeComponentsDrawer();
            _drawers[1] = new RuntimeComponentsDrawer();
            _drawers[2] = new RuntimeComponentsDrawer();
        }

        private List<IEcsPool> _componentPoolsBuffer = new List<IEcsPool>(64);


        #region Properties
        private static ComponentColorMode AutoColorMode
        {
            get { return UserSettingsPrefs.instance.ComponentColorMode; }
            set { UserSettingsPrefs.instance.ComponentColorMode = value; }
        }
        private static bool IsShowHidden
        {
            get { return UserSettingsPrefs.instance.IsShowHidden; }
            set { UserSettingsPrefs.instance.IsShowHidden = value; }
        }
        private static bool IsShowRuntimeComponents
        {
            get { return UserSettingsPrefs.instance.IsShowRuntimeComponents; }
            set { UserSettingsPrefs.instance.IsShowRuntimeComponents = value; }
        }
        #endregion

        #region reflection cache
        internal class RuntimeComponentReflectionCache
        {
            public readonly Type Type;

            public readonly bool IsUnityObjectType;
            public readonly bool IsUnitySerializable;
            public readonly bool IsUnmanaged;

            public readonly FieldInfoData[] Fields;

            private RefEditorWrapper[] _wrappers = new RefEditorWrapper[2];
            public RefEditorWrapper GetWrapper(int depth)
            {
                return _wrappers[depth];
            }

            public RuntimeComponentReflectionCache(Type type)
            {

                Type = type;
                ResetWrappers();
                IsUnmanaged = UnsafeUtility.IsUnmanaged(type);
                IsUnityObjectType = typeof(UnityObject).IsAssignableFrom(type);
                IsUnitySerializable = IsUnityObjectType || (!type.IsGenericType && type.IsSerializable);

                if (type == typeof(void)) { return; }

                if (IsUnitySerializable == false)
                {
                    var fieldInfos = type.GetFields(fieldFlags);
                    Fields = new FieldInfoData[fieldInfos.Length];
                    for (int i = 0; i < fieldInfos.Length; i++)
                    {
                        var fieldInfo = fieldInfos[i];
                        Fields[i] = new FieldInfoData(fieldInfo);
                    }
                }
            }
            public void ResetWrappers()
            {
                _wrappers[0] = RefEditorWrapper.Take();
                _wrappers[1] = RefEditorWrapper.Take();
            }
            public readonly struct FieldInfoData
            {
                public readonly FieldInfo FieldInfo;
                public readonly Type FieldType;
                public readonly string UnityFormatName;
                public readonly bool IsUnityObjectField;
                public readonly bool IsPassToSerialize;
                public readonly RuntimeComponentReflectionCache ValueTypeReflectionCache;
                public FieldInfoData(FieldInfo fieldInfo)
                {
                    FieldInfo = fieldInfo;
                    FieldType = fieldInfo.FieldType;
                    IsUnityObjectField = typeof(UnityObject).IsAssignableFrom(fieldInfo.FieldType);
                    UnityFormatName = UnityEditorUtility.TransformFieldName(fieldInfo.Name);
                    IsPassToSerialize =
                        (fieldInfo.IsPublic || fieldInfo.HasAttribute<SerializeField>() || fieldInfo.HasAttribute<SerializeReference>()) &&
                        (fieldInfo.IsInitOnly || fieldInfo.HasAttribute<System.NonSerializedAttribute>()) == false;
                    ValueTypeReflectionCache = FieldType.IsValueType ? GetRuntimeComponentReflectionCache(FieldType) : null;
                }
                public FieldInfoData(FieldInfo fieldInfo, Type fieldType, string unityFormatName, bool isPassToSerialize = true)
                {
                    FieldInfo = fieldInfo;
                    FieldType = fieldType;
                    UnityFormatName = unityFormatName;
                    IsUnityObjectField = typeof(UnityObject).IsAssignableFrom(fieldType);
                    IsPassToSerialize = isPassToSerialize;
                    ValueTypeReflectionCache = FieldType.IsValueType ? GetRuntimeComponentReflectionCache(FieldType) : null;
                }
                public RuntimeComponentReflectionCache GetReflectionCache(Type type)
                {
                    if (ValueTypeReflectionCache != null)
                    {
                        return ValueTypeReflectionCache;
                    }
                    return GetRuntimeComponentReflectionCache(type);
                }
            }
        }
        private static Dictionary<Type, RuntimeComponentReflectionCache> _runtimeComponentReflectionCaches = new Dictionary<Type, RuntimeComponentReflectionCache>();
        private static RuntimeComponentReflectionCache GetRuntimeComponentReflectionCache(Type type)
        {
            if (_runtimeComponentReflectionCaches.TryGetValue(type, out RuntimeComponentReflectionCache result) == false)
            {
                result = new RuntimeComponentReflectionCache(type);
                _runtimeComponentReflectionCaches.Add(type, result);
            }
            return result;
        }
        #endregion

        #region draw world component
        public static void DrawWorldComponents(EcsWorld world)
        {
            if (_runtimeComponentsDepth == 0)
            {
                _drawers[_runtimeComponentsDepth].DrawWorldComponents_Internal(world);
            }
        }
        private void DrawWorldComponents_Internal(EcsWorld world)
        {
            bool isNull = world == null || world.IsDestroyed || world.ID == 0;
            if (isNull) { return; }
            using (EcsGUI.Layout.BeginVertical(UnityEditorUtility.GetTransperentBlackBackgrounStyle()))
            {
                IsShowRuntimeComponents = EditorGUILayout.BeginFoldoutHeaderGroup(IsShowRuntimeComponents, "RUNTIME COMPONENTS", EditorStyles.foldout);
                EditorGUILayout.EndFoldoutHeaderGroup();
                if (IsShowRuntimeComponents == false) { return; }

                var worldID = world.ID;
                var cmps = world.GetWorldComponents();
                int index = -1;
                int total = 9;
                foreach (var cmp in cmps)
                {
                    index++;
                    var meta = cmp.ComponentType.ToMeta();
                    if (meta.IsHidden == false || IsShowHidden)
                    {
                        Type componentType = cmp.ComponentType;

                        object data = cmp.GetRaw(worldID);

                        ExpandMatrix expandMatrix = ExpandMatrix.Take(componentType);

                        float padding = EditorGUIUtility.standardVerticalSpacing;
                        Rect optionButton = GUILayoutUtility.GetLastRect();
                        optionButton.yMin = optionButton.yMax;
                        optionButton.yMax += EcsGUI.HeadIconsRect.height;
                        optionButton.xMin = optionButton.xMax - 64;
                        optionButton.center += Vector2.up * padding * 2f;
                        //Canceling isExpanded
                        if (EcsGUI.ClickTest(optionButton))
                        {
                            ref bool isExpanded = ref expandMatrix.Down();
                            isExpanded = !isExpanded;
                        }

                        Color panelColor = EcsGUI.SelectPanelColor(meta, index, total);
                        using (EcsGUI.Layout.BeginVertical(panelColor.SetAlpha(EscEditorConsts.COMPONENT_DRAWER_ALPHA)))
                        {
                            EditorGUI.BeginChangeCheck();

                            //Edit script button
                            if (ScriptsCache.TryGetScriptAsset(meta, out MonoScript script))
                            {
                                optionButton = EcsGUI.HeadIconsRect.MoveTo(optionButton.center - (Vector2.right * optionButton.width));
                                EcsGUI.ScriptAssetButton(optionButton, script);
                            }
                            //Description icon
                            if (string.IsNullOrEmpty(meta.Description.Text) == false)
                            {
                                optionButton = EcsGUI.HeadIconsRect.MoveTo(optionButton.center - (Vector2.right * optionButton.width));
                                EcsGUI.DescriptionIcon(optionButton, meta.Description.Text);
                            }

                            RuntimeComponentReflectionCache.FieldInfoData componentInfoData = new RuntimeComponentReflectionCache.FieldInfoData(null, componentType, meta.Name);
                            if (DrawRuntimeData(ref componentInfoData, UnityEditorUtility.GetLabel(meta.Name), expandMatrix, data, out object resultData))
                            {
                                cmp.SetRaw(worldID, resultData);
                            }

                        }
                    }
                }
            }
        }
        #endregion

        #region draw entity component
        public static void DrawRuntimeComponents(int entityID, EcsWorld world, bool isWithFoldout, bool isRoot)
        {
            if (isRoot)
            {
                _runtimeComponentsDepth = 0;
            }
            else
            {
                _runtimeComponentsDepth++;
            }

            _drawers[_runtimeComponentsDepth].DrawRuntimeComponents(entityID, world, isWithFoldout);

            _runtimeComponentsDepth--;
        }
        private void DrawRuntimeComponents(int entityID, EcsWorld world, bool isWithFoldout)
        {
            using (EcsGUI.Layout.BeginVertical(UnityEditorUtility.GetTransperentBlackBackgrounStyle())) using (EcsGUI.SetIndentLevel(0))
            {
                if (_runtimeComponentsDepth >= RuntimeComponentsMaxDepth)
                {
                    GUILayout.Label("Max depth for inspecting components at runtime");
                    return;
                }
                if (isWithFoldout)
                {
                    IsShowRuntimeComponents = EditorGUILayout.BeginFoldoutHeaderGroup(IsShowRuntimeComponents, "RUNTIME COMPONENTS", EditorStyles.foldout);
                    EditorGUILayout.EndFoldoutHeaderGroup();
                }
                if (isWithFoldout == false || IsShowRuntimeComponents)
                {
                    if (EcsGUI.Layout.AddComponentButtons(out Rect dropDownRect))
                    {
                        RuntimeComponentsUtility.GetAddComponentGenericMenu(world).Open(dropDownRect, entityID);
                    }

                    using (EcsGUI.SetBackgroundColor(GUI.color.SetAlpha(0.16f)))
                    {
                        GUILayout.Box("", UnityEditorUtility.GetWhiteStyle(), GUILayout.ExpandWidth(true));
                    }
                    IsShowHidden = EditorGUI.Toggle(GUILayoutUtility.GetLastRect(), "Show Hidden", IsShowHidden);


                    world.GetComponentPoolsFor(entityID, _componentPoolsBuffer);
                    for (int i = 0; i < _componentPoolsBuffer.Count; i++)
                    {
                        DrawRuntimeComponent(entityID, _componentPoolsBuffer[i], 9, i);
                    }
                }
            }
        }
        private void DrawRuntimeComponent(int entityID, IEcsPool pool, int total, int index)
        {
            var meta = pool.ComponentType.ToMeta();
            if (meta.IsHidden == false || IsShowHidden)
            {
                Type componentType = pool.ComponentType;

                object data = pool.GetRaw(entityID);

                ExpandMatrix expandMatrix = ExpandMatrix.Take(componentType);

                float padding = EditorGUIUtility.standardVerticalSpacing;
                Rect optionButton = GUILayoutUtility.GetLastRect();
                optionButton.yMin = optionButton.yMax;
                optionButton.yMax += EcsGUI.HeadIconsRect.height;
                optionButton.xMin = optionButton.xMax - 64;
                optionButton.center += Vector2.up * padding * 2f;
                //Canceling isExpanded
                if (EcsGUI.ClickTest(optionButton))
                {
                    ref bool isExpanded = ref expandMatrix.Down();
                    isExpanded = !isExpanded;
                }

                Color panelColor = EcsGUI.SelectPanelColor(meta, index, total);

                using (EcsGUI.Layout.BeginVertical(panelColor.SetAlpha(EscEditorConsts.COMPONENT_DRAWER_ALPHA)))
                {
                    EditorGUI.BeginChangeCheck();

                    //Close button
                    optionButton.xMin = optionButton.xMax - EcsGUI.HeadIconsRect.width;
                    if (EcsGUI.CloseButton(optionButton))
                    {
                        pool.Del(entityID);
                        return;
                    }
                    //Edit script button
                    if (ScriptsCache.TryGetScriptAsset(meta, out MonoScript script))
                    {
                        optionButton = EcsGUI.HeadIconsRect.MoveTo(optionButton.center - (Vector2.right * optionButton.width));
                        EcsGUI.ScriptAssetButton(optionButton, script);
                    }
                    //Description icon
                    if (string.IsNullOrEmpty(meta.Description.Text) == false)
                    {
                        optionButton = EcsGUI.HeadIconsRect.MoveTo(optionButton.center - (Vector2.right * optionButton.width));
                        EcsGUI.DescriptionIcon(optionButton, meta.Description.Text);
                    }

                    RuntimeComponentReflectionCache.FieldInfoData componentInfoData = new RuntimeComponentReflectionCache.FieldInfoData(null, componentType, meta.Name);

                    if (DrawRuntimeData(ref componentInfoData, UnityEditorUtility.GetLabel(meta.Name), expandMatrix, data, out object resultData))
                    {
                        pool.SetRaw(entityID, resultData);
                    }
                }
            }
        }
        #endregion



        #region draw data
        private bool DrawRuntimeData(ref RuntimeComponentReflectionCache.FieldInfoData fieldInfoData, GUIContent label, ExpandMatrix expandMatrix, object data, out object outData)
        {
            outData = data;
            Type type = data == null ? typeof(void) : data.GetType();

            RuntimeComponentReflectionCache cache = fieldInfoData.GetReflectionCache(type);

            bool isUnityObjectField = fieldInfoData.IsUnityObjectField;
            if (isUnityObjectField == false && data == null)
            {
                EditorGUILayout.TextField(label, "Null");
                return false;
            }
            bool isUnityObjectType = cache.IsUnityObjectType;

            ref bool isExpanded = ref expandMatrix.Down();
            bool changed = false;


            if (cache.IsUnitySerializable == false)
            {
                isExpanded = EditorGUILayout.BeginFoldoutHeaderGroup(isExpanded, label, EditorStyles.foldout);
                EditorGUILayout.EndFoldoutHeaderGroup();

                if (isExpanded)
                {
                    using (EcsGUI.UpIndentLevel())
                    {
                        for (int j = 0, jMax = cache.Fields.Length; j < jMax; j++)
                        {
                            var field = cache.Fields[j];
                            if (DrawRuntimeData(ref field, UnityEditorUtility.GetLabel(field.UnityFormatName), expandMatrix, field.FieldInfo.GetValue(data), out object fieldData))
                            {
                                field.FieldInfo.SetValue(data, fieldData);
                                outData = data;
                                changed = true;
                            }
                        }
                    }
                }
            }
            else
            {
                Type fieldType = fieldInfoData.FieldType;
                if (isUnityObjectType || isUnityObjectField)
                {
                    EditorGUI.BeginChangeCheck();
                    var uobj = UnsafeUtility.As<object, UnityObject>(ref data);

                    bool isComponent = typeof(UnityComponent).IsAssignableFrom(fieldType);
                    if (isComponent)
                    {
                        uobj = EditorGUILayout.ObjectField(label, uobj, typeof(UnityObject), true);
                    }
                    else
                    {
                        uobj = EditorGUILayout.ObjectField(label, uobj, fieldType, true);
                    }

                    if (EditorGUI.EndChangeCheck())
                    {
                        if (isComponent && uobj is GameObject go)
                        {
                            uobj = go.GetComponent(fieldType);
                        }

                        outData = uobj;
                        changed = true;
                    }
                }
                else
                {
                    EditorGUI.BeginChangeCheck();

                    RefEditorWrapper wrapper = cache.GetWrapper(_runtimeComponentsDepth);

                    wrapper.data = data;
                    wrapper.SO.Update();

                    wrapper.IsExpanded = isExpanded;
                    try
                    {
                        EditorGUILayout.PropertyField(wrapper.Property, label, true);
                    }
                    catch (ArgumentException)
                    {
                        if (Event.current.type != EventType.Repaint)
                        {
                            throw;
                        }
                    }
                    finally
                    {
                        if (EditorGUI.EndChangeCheck())
                        {
                            wrapper.SO.ApplyModifiedProperties();
                            outData = wrapper.Data;
                            changed = true;
                        }
                        isExpanded = wrapper.IsExpanded;
                    }
                }
            }

            expandMatrix.Up();
            return changed;
        }
        #endregion
    }
}
#endif