using System;
using System.Collections.Generic;
using System.Linq;
using Aliciza.UXTool;
using AlicizaX.UI.Runtime;
using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEditor.Experimental.SceneManagement;
using UnityEngine;
using UnityEngine.UIElements;
using Object = UnityEngine.Object;

public class UXHierarchyWindow : EditorWindow
{
    const string FoldoutPrefsKeyBase = "UXHierarchy_Foldouts_v1"; // base key
    const string WindowTitle = "UXHierarchy";

    VisualElement root;
    ScrollView scroll;
    VisualElement treeContainer;
    TextField searchField;
    VisualElement rootDropZone; // accepts drops to root

    // foldout state: instanceID -> bool (true = expanded)
    Dictionary<int, bool> foldStates = new Dictionary<int, bool>();

    // flat ordered list of GameObjects displayed (for shift-range selection)
    List<GameObject> flatList = new List<GameObject>();

    // selection state in the window (keeps synced with UnityEditor.Selection)
    List<GameObject> selectedObjects = new List<GameObject>();
    int lastClickedIndex = -1;

    // delete-key auto-repeat
    bool deleteKeyHeld = false;
    double nextAutoDeleteTime = 0;
    const double DeleteInitialDelay = 0.35;
    const double DeleteRepeatInterval = 0.08;

    // rename state
    TextField activeRenameField = null;

    // drag feedback tracking
    VisualElement currentDragTargetRow = null;

    enum DragDropMode
    {
        None,
        InsertBefore,
        InsertAfter,
        MakeChild
    }

    DragDropMode currentDragMode = DragDropMode.None;

    const float DragBorderWidth = 3f; // thickness of the insert line

    public static void ShowWindow()
    {
        var w = GetWindow<UXHierarchyWindow>(false, WindowTitle);
        w.minSize = new Vector2(240, 200);
        w.Show();
    }

    void OnEnable()
    {
        LoadFoldStates();

        root = rootVisualElement;
        root.styleSheets.Clear();
        root.style.paddingTop = 4;
        root.style.paddingLeft = 4;
        root.style.paddingRight = 4;

        // header row: search + refresh icon (removed title text)
        var headerRow = new VisualElement();
        headerRow.style.flexDirection = FlexDirection.Row;
        headerRow.style.alignItems = Align.Center;
        headerRow.style.marginBottom = 6;

        // search icon
        var searchIcon = new Image();
        Texture si = EditorGUIUtility.IconContent("Search Icon").image ?? EditorGUIUtility.IconContent("d_Search Icon").image ?? EditorGUIUtility.IconContent("SearchField").image;
        if (si != null)
        {
            searchIcon.image = si;
            searchIcon.style.width = 16;
            searchIcon.style.height = 16;
            searchIcon.style.marginRight = 4;
            headerRow.Add(searchIcon);
        }

        searchField = new TextField();
        searchField.name = "uxh-search";
        searchField.style.flexGrow = 1;
        searchField.style.minWidth = 80;
        searchField.tooltip = "Search by name (case-insensitive)";
        searchField.RegisterValueChangedCallback(evt => RebuildTree());
        headerRow.Add(searchField);

        // refresh icon-only button
        var refreshBtn = new Button(() => RebuildTree());
        Texture rtex = EditorGUIUtility.IconContent("Refresh").image ?? EditorGUIUtility.IconContent("d_Refresh").image;
        if (rtex != null)
        {
            var img = new Image() { image = rtex };
            img.style.width = 16;
            img.style.height = 16;
            refreshBtn.Add(img);
            refreshBtn.tooltip = "Refresh";
        }
        else
        {
            refreshBtn.text = "Refresh";
        }

        refreshBtn.style.marginLeft = 6;
        headerRow.Add(refreshBtn);

        root.Add(headerRow);

        // scroll area
        scroll = new ScrollView(ScrollViewMode.Vertical);
        scroll.style.flexGrow = 1;
        root.Add(scroll);

        // root drop zone: small area at top to drop to root
        rootDropZone = new VisualElement();
        rootDropZone.style.height = 18;
        rootDropZone.style.unityTextAlign = TextAnchor.MiddleCenter;
        rootDropZone.style.marginBottom = 4;
        rootDropZone.style.alignItems = Align.Center;
        rootDropZone.style.justifyContent = Justify.Center;
        rootDropZone.style.backgroundColor = new StyleColor(new Color(0, 0, 0, 0));
        rootDropZone.Add(new Label("Drop here to make root"));
        scroll.contentContainer.Add(rootDropZone);

        treeContainer = new VisualElement();
        treeContainer.name = "treeContainer";
        treeContainer.style.flexDirection = FlexDirection.Column;
        scroll.contentContainer.Add(treeContainer);

        // event handlers
        root.RegisterCallback<KeyDownEvent>(OnKeyDown);
        root.RegisterCallback<KeyUpEvent>(OnKeyUp);
        root.RegisterCallback<FocusOutEvent>(e => StopRename());

        scroll.AddManipulator(new ContextualMenuManipulator(evt =>
        {
            if (PrefabStageUtils.InEmptyStage) return;

            var t = evt.target as VisualElement;
            bool hasPathAncestor = false;
            while (t != null)
            {
                if (t.userData is string)
                {
                    hasPathAncestor = true;
                    break;
                }

                t = t.parent as VisualElement;
            }

            if (!hasPathAncestor)
            {
                evt.menu.AppendAction("创建空物体", a => CreateEmptyUI(null), a => DropdownMenuAction.Status.Normal);
                CreateCommonUIMenu(evt, null);
            }
        }));

        scroll.RegisterCallback<ClickEvent>(evt =>
        {
            if (evt.button != 0) return;

            VisualElement t = evt.target as VisualElement;
            bool clickedRow = false;

            while (t != null)
            {
                if (t.ClassListContains("uxh-row") || t.userData is GameObject)
                {
                    clickedRow = true;
                    break;
                }

                t = t.parent as VisualElement;
            }

            if (!clickedRow)
            {
                selectedObjects.Clear();
                Selection.objects = new Object[0];
                UpdateSelectionHighlighting();

                evt.StopImmediatePropagation();
            }
        });


        rootDropZone.RegisterCallback<DragEnterEvent>(evt =>
        {
            if (PrefabStageUtils.InEmptyStage) return;
            rootDropZone.style.backgroundColor = new StyleColor(new Color(0.2f, 0.2f, 0.2f, 0.06f));
            evt.StopImmediatePropagation();
        });
        rootDropZone.RegisterCallback<DragLeaveEvent>(evt =>
        {
            if (PrefabStageUtils.InEmptyStage) return;
            rootDropZone.style.backgroundColor = new StyleColor(Color.clear);
            if (currentDragTargetRow != null)
            {
                ClearDragHighlight(currentDragTargetRow);
            }

            evt.StopImmediatePropagation();
        });
        rootDropZone.RegisterCallback<DragUpdatedEvent>(evt =>
        {
            if (PrefabStageUtils.InEmptyStage) return;
            if (DragAndDrop.objectReferences != null && DragAndDrop.objectReferences.Length > 0) DragAndDrop.visualMode = DragAndDropVisualMode.Move;
            evt.StopImmediatePropagation();
        });
        rootDropZone.RegisterCallback<DragPerformEvent>(evt =>
        {
            if (DragAndDrop.objectReferences != null && DragAndDrop.objectReferences.Length > 0 && !PrefabStageUtils.InEmptyStage)
            {
                var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
                Transform rootParent = null;
                if (prefabStage != null && prefabStage.prefabContentsRoot != null)
                    rootParent = prefabStage.prefabContentsRoot.transform;
                else
                    rootParent = null; // null means scene root

                // perform reparent to root (or to prefabContentsRoot)
                foreach (var o in DragAndDrop.objectReferences)
                {
                    var draggedGO = o as GameObject;
                    if (draggedGO == null) continue;
                    // if drag source is same prefab, allow
                    if (rootParent != null)
                    {
                        Undo.SetTransformParent(draggedGO.transform, rootParent, "Reparent to root (UXHierarchy)");
                        draggedGO.transform.SetSiblingIndex(rootParent.childCount - 1);
                    }
                    else
                    {
                        // move to scene root
                        Undo.SetTransformParent(draggedGO.transform, null, "Reparent to root (UXHierarchy)");
                    }
                }

                if (prefabStage != null)
                {
                    try
                    {
                        EditorSceneManager.MarkSceneDirty(prefabStage.scene);
                    }
                    catch
                    {
                    }
                }
                else
                {
                    EditorSceneManager.MarkSceneDirty(EditorSceneManager.GetActiveScene());
                }

                RebuildTree();
                DragAndDrop.AcceptDrag();
            }

            rootDropZone.style.backgroundColor = new StyleColor(Color.clear);
            evt.StopImmediatePropagation();
        });

        // clear drag highlight when leaving the whole tree or root
        treeContainer.RegisterCallback<DragLeaveEvent>(evt =>
        {
            if (currentDragTargetRow != null)
            {
                ClearDragHighlight(currentDragTargetRow);
            }

            evt.StopImmediatePropagation();
        });
        root.RegisterCallback<DragLeaveEvent>(evt =>
        {
            if (currentDragTargetRow != null)
            {
                ClearDragHighlight(currentDragTargetRow);
            }

            rootDropZone.style.backgroundColor = new StyleColor(Color.clear);
            evt.StopImmediatePropagation();
        });

        // keep selection in sync if external selection changes
        Selection.selectionChanged += OnUnitySelectionChanged;

        // hierarchy changes (scene/prefab content changes)
        EditorApplication.hierarchyChanged += OnHierarchyChanged;
        EditorApplication.update += EditorUpdate;

        RebuildTree();
    }

    void OnDisable()
    {
        Selection.selectionChanged -= OnUnitySelectionChanged;
        EditorApplication.hierarchyChanged -= OnHierarchyChanged;
        EditorApplication.update -= EditorUpdate;

        SaveFoldStates();
    }

    void OnHierarchyChanged()
    {
        RebuildTree();
    }

    void EditorUpdate()
    {
        // handle delete auto-repeat while held
        if (deleteKeyHeld && EditorApplication.timeSinceStartup >= nextAutoDeleteTime)
        {
            DoDeleteSelected();
            nextAutoDeleteTime = EditorApplication.timeSinceStartup + DeleteRepeatInterval;
        }
    }

    void OnUnitySelectionChanged()
    {
        var sel = Selection.gameObjects.ToList();
        selectedObjects = sel;
        UpdateSelectionHighlighting();
        Repaint();
    }

    void RebuildTree()
    {
        // clear any drag highlight to avoid residual visuals
        if (currentDragTargetRow != null)
        {
            ClearDragHighlight(currentDragTargetRow);
            currentDragTargetRow = null;
            currentDragMode = DragDropMode.None;
        }

        treeContainer.Clear();
        flatList.Clear();

        string search = (searchField != null) ? searchField.value?.Trim() ?? "" : "";

        var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
        if (prefabStage != null && prefabStage.prefabContentsRoot != null)
        {
            var root = prefabStage.prefabContentsRoot;
            var prefabRoot = prefabStage.prefabContentsRoot.GetComponent<Canvas>() != null ? root.transform : root.transform.parent;
            for (int i = 0; i < prefabRoot.transform.childCount; ++i)
            {
                var child = prefabRoot.transform.GetChild(i).gameObject;
                var node = CreateNodeRecursive(child, 0, search);
                if (node != null) treeContainer.Add(node);
            }
        }
        else
        {
            var roots = EditorSceneManager.GetActiveScene().GetRootGameObjects();
            foreach (var go in roots)
            {
                var node = CreateNodeRecursive(go, 0, search);
                if (node != null) treeContainer.Add(node);
            }
        }

        UpdateSelectionHighlighting();
    }

    VisualElement CreateNodeRecursive(GameObject go, int indent, string search)
    {
        // decide whether this node or any descendant matches the search
        bool matches = string.IsNullOrEmpty(search) || go.name.IndexOf(search, StringComparison.OrdinalIgnoreCase) >= 0;
        bool isPrefab = PrefabUtility.IsPartOfAnyPrefab(go);
        // process children
        List<VisualElement> childNodes = new List<VisualElement>();
        if (!isPrefab)
        {
            for (int i = 0; i < go.transform.childCount; ++i)
            {
                var child = go.transform.GetChild(i).gameObject;
                var childNode = CreateNodeRecursive(child, indent + 1, search);
                if (childNode != null) childNodes.Add(childNode);
            }
        }

        // if nothing matches and no children match, skip
        if (!matches && childNodes.Count == 0) return null;

        // otherwise build node
        flatList.Add(go);
        int indexInFlat = flatList.Count - 1;

        var node = new VisualElement();
        node.style.flexDirection = FlexDirection.Column;
        node.userData = go;

        // row
        var row = new VisualElement();
        row.style.flexDirection = FlexDirection.Row;
        row.style.alignItems = Align.Center;
        row.style.paddingLeft = indent * 12;
        row.style.paddingTop = 2;
        row.style.paddingBottom = 2;
        row.style.flexGrow = 0;
        row.AddToClassList("uxh-row");
        row.style.paddingRight = 6;

        // only show fold icon if we have visible children
        bool hasVisibleChildren = childNodes.Count > 0;
        Label foldLabel = null;

        if (hasVisibleChildren && !isPrefab)
        {
            foldLabel = new Label();
            foldLabel.style.width = 16;
            foldLabel.style.height = 16;
            foldLabel.style.alignSelf = Align.Center;
            foldLabel.style.marginRight = 4;
            foldLabel.style.unityTextAlign = TextAnchor.MiddleCenter;
            foldLabel.tooltip = "Expand / Collapse";

            int id = go.GetInstanceID();
            bool expanded = foldStates.ContainsKey(id) ? foldStates[id] : true;
            foldLabel.text = expanded ? "▼" : "▶";
            foldLabel.style.unityFontStyleAndWeight = FontStyle.Bold;
            foldLabel.style.fontSize = 10;
            foldLabel.style.color = new StyleColor(new Color(0.55f, 0.55f, 0.55f));

            // toggle on click
            foldLabel.RegisterCallback<MouseDownEvent>((evt) =>
            {
                if (evt.button == 0)
                {
                    expanded = !expanded;
                    foldStates[id] = expanded;
                    foldLabel.text = expanded ? "▼" : "▶";
                    SaveFoldStates();
                    var childrenContainer = node.Q<VisualElement>("children");
                    if (childrenContainer != null)
                        childrenContainer.style.display = expanded ? DisplayStyle.Flex : DisplayStyle.None;
                    evt.StopImmediatePropagation();
                }
            });

            // hover color
            foldLabel.RegisterCallback<MouseEnterEvent>((evt) => foldLabel.style.color = new StyleColor(Color.white));
            foldLabel.RegisterCallback<MouseLeaveEvent>((evt) => foldLabel.style.color = new StyleColor(new Color(0.55f, 0.55f, 0.55f)));

            row.Add(foldLabel);
        }
        else
        {
            // add spacer so icons align
            var spacer = new VisualElement();
            spacer.style.width = 16;
            spacer.style.height = 16;
            spacer.style.marginRight = 4;
            row.Add(spacer);
        }

        // icon
        var icon = new Image();
        icon.image = GetObjectIcon(go);
        icon.style.width = 16;
        icon.style.height = 16;
        icon.style.alignSelf = Align.Center;
        icon.style.marginRight = 4;
        row.Add(icon);

        // label
        var label = new Label(go.name);
        label.style.flexGrow = 1;
        label.style.unityTextAlign = TextAnchor.MiddleLeft;
        label.userData = indexInFlat;
        row.Add(label);

        row.AddManipulator(new ContextualMenuManipulator(evt =>
        {
            // right click: node menu
            if (evt.button == 1 && !PrefabStageUtils.InEmptyStage)
            {
                SelectSingle(go);
                evt.menu.AppendAction("创建空物体", a => CreateEmptyUI(go), a => DropdownMenuAction.Status.Normal);
                evt.menu.AppendAction("删除", a =>
                {
                    SelectSingle(go);
                    DoDeleteSelected();
                }, a => DropdownMenuAction.Status.Normal);
                CreateCommonUIMenu(evt, go);
                CreateControlerUIMenu(evt, go);
                evt.StopImmediatePropagation();
            }
        }));
        // mouse handling
        row.RegisterCallback<MouseDownEvent>(evt =>
        {
            // left click selection
            if (evt.button == 0)
            {
                bool ctrl = evt.ctrlKey || evt.commandKey;
                bool shift = evt.shiftKey;

                int clickedIndex = (int)label.userData;

                if (shift && lastClickedIndex >= 0)
                {
                    int a = Math.Min(lastClickedIndex, clickedIndex);
                    int b = Math.Max(lastClickedIndex, clickedIndex);
                    var range = flatList.GetRange(a, b - a + 1);
                    selectedObjects = range.Where(x => x != null).ToList();
                    Selection.objects = selectedObjects.ToArray();
                }
                else if (ctrl)
                {
                    if (selectedObjects.Contains(go)) selectedObjects.Remove(go);
                    else selectedObjects.Add(go);
                    Selection.objects = selectedObjects.ToArray();
                    lastClickedIndex = clickedIndex;
                }
                else
                {
                    SelectSingle(go);
                    lastClickedIndex = clickedIndex;
                }

                evt.StopImmediatePropagation();
            }

            // double-click print name
            if (evt.clickCount == 2 && evt.button == 0 && isPrefab)
            {
                var prefabAsset = PrefabUtility.GetCorrespondingObjectFromSource(go);
                var prefabPath = AssetDatabase.GetAssetPath(prefabAsset);
                if (prefabPath.StartsWith(Def_UXGUIPath.UIResRootPath))
                {
                    PrefabStageUtils.SwitchStage(prefabPath);
                }

                evt.StopImmediatePropagation();
            }
        });

        // drag start: when moving mouse while left pressed
        row.RegisterCallback<MouseMoveEvent>(evt =>
        {
            if (evt.pressedButtons == 1)
            {
                if (!selectedObjects.Contains(go)) SelectSingle(go);
                DragAndDrop.PrepareStartDrag();
                DragAndDrop.objectReferences = selectedObjects.ToArray();
                DragAndDrop.StartDrag("UXHierarchyDrag");
                evt.StopImmediatePropagation();
            }
        });

        // drag feedback & drop handling on row
        row.RegisterCallback<DragEnterEvent>(evt =>
        {
            /* highlight handled in DragUpdated */
            evt.StopImmediatePropagation();
        });
        row.RegisterCallback<DragLeaveEvent>(evt =>
        {
            ClearDragHighlight(row);
            evt.StopImmediatePropagation();
        });
        row.RegisterCallback<DragUpdatedEvent>(evt =>
        {
            if (DragAndDrop.objectReferences != null && DragAndDrop.objectReferences.Length > 0)
            {
                // compute position ratio
                float h = Math.Max(1.0f, row.layout.height);
                float y = evt.localMousePosition.y;
                float ratio = y / h;

                DragAndDrop.visualMode = DragAndDropVisualMode.Move;

                DragDropMode mode;
                if (ratio < 0.25f) mode = DragDropMode.InsertBefore;
                else if (ratio > 0.75f) mode = DragDropMode.InsertAfter;
                else mode = DragDropMode.MakeChild;

                // only update highlight if changed to reduce style churn
                if (currentDragTargetRow != row || currentDragMode != mode)
                    ApplyDragHighlight(row, mode);
            }

            evt.StopImmediatePropagation();
        });

        row.RegisterCallback<DragPerformEvent>(evt =>
        {
            if (DragAndDrop.objectReferences != null && DragAndDrop.objectReferences.Length > 0)
            {
                float h = Math.Max(1.0f, row.layout.height);
                float y = evt.localMousePosition.y;
                float ratio = y / h;

                DragDropMode mode;
                if (ratio < 0.25f) mode = DragDropMode.InsertBefore;
                else if (ratio > 0.75f) mode = DragDropMode.InsertAfter;
                else mode = DragDropMode.MakeChild;

                PerformDropOnRow(go, mode);
                DragAndDrop.AcceptDrag();
            }

            ClearDragHighlight(row);
            evt.StopImmediatePropagation();
        });

        // add row to node
        node.Add(row);

        // children container
        var childrenContainer = new VisualElement();
        childrenContainer.name = "children";
        childrenContainer.style.flexDirection = FlexDirection.Column;
        childrenContainer.style.marginLeft = 0;
        childrenContainer.style.display = hasVisibleChildren ? DisplayStyle.Flex : DisplayStyle.None;
        node.Add(childrenContainer);

        // populate visible children
        foreach (var cn in childNodes) childrenContainer.Add(cn);

        return node;
    }

    void ApplyDragHighlight(VisualElement row, DragDropMode mode)
    {
        // clear previous if different
        if (currentDragTargetRow != null && currentDragTargetRow != row)
        {
            ClearDragHighlight(currentDragTargetRow);
            currentDragTargetRow = null;
            currentDragMode = DragDropMode.None;
        }

        // store
        currentDragTargetRow = row;
        currentDragMode = mode;

        // reset style first
        row.style.borderTopWidth = new StyleFloat(0f);
        row.style.borderBottomWidth = new StyleFloat(0f);
        row.style.borderLeftWidth = new StyleFloat(0f);
        row.style.borderRightWidth = new StyleFloat(0f);
        row.style.borderTopColor = new StyleColor(Color.clear);
        row.style.borderBottomColor = new StyleColor(Color.clear);
        row.style.backgroundColor = new StyleColor(Color.clear);

        if (mode == DragDropMode.InsertBefore)
        {
            row.style.borderTopWidth = new StyleFloat(DragBorderWidth);
            row.style.borderTopColor = new StyleColor(Color.cyan);
        }
        else if (mode == DragDropMode.InsertAfter)
        {
            row.style.borderBottomWidth = new StyleFloat(DragBorderWidth);
            row.style.borderBottomColor = new StyleColor(Color.cyan);
        }
        else if (mode == DragDropMode.MakeChild)
        {
            row.style.backgroundColor = new StyleColor(new Color(0.2f, 0.2f, 0.2f, 0.06f));
        }
    }

    void ClearDragHighlight(VisualElement row)
    {
        if (row == null) return;
        row.style.borderTopWidth = new StyleFloat(0f);
        row.style.borderBottomWidth = new StyleFloat(0f);
        row.style.borderLeftWidth = new StyleFloat(0f);
        row.style.borderRightWidth = new StyleFloat(0f);
        row.style.borderTopColor = new StyleColor(Color.clear);
        row.style.borderBottomColor = new StyleColor(Color.clear);
        row.style.backgroundColor = new StyleColor(Color.clear);
        if (currentDragTargetRow == row)
        {
            currentDragTargetRow = null;
            currentDragMode = DragDropMode.None;
        }
    }

    void PerformDropOnRow(GameObject targetGO, DragDropMode mode)
    {
        var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
        Transform targetParent = null;

        if (mode == DragDropMode.MakeChild)
        {
            targetParent = targetGO.transform;
        }
        else
        {
            // insert before/after among targetGO's siblings
            targetParent = targetGO.transform.parent;
        }

        foreach (var o in DragAndDrop.objectReferences)
        {
            var draggedGO = o as GameObject;
            if (draggedGO == null) continue;
            // prevent making parent its own child
            if (IsAncestor(draggedGO.transform, targetGO.transform)) continue;

            if (mode == DragDropMode.MakeChild)
            {
                Undo.SetTransformParent(draggedGO.transform, targetParent, "Reparent GameObject (UXHierarchy)");
                // place at end
                draggedGO.transform.SetSiblingIndex(targetParent.childCount - 1);
            }
            else
            {
                // when targetParent == null -> scene root
                Undo.SetTransformParent(draggedGO.transform, targetParent, "Reparent GameObject (UXHierarchy)");

                int targetIndex;
                if (targetParent != null)
                {
                    var siblings = GetSiblings(targetParent);
                    targetIndex = Array.IndexOf(siblings, targetGO);
                }
                else
                {
                    var roots = GetSceneRoots();
                    targetIndex = Array.IndexOf(roots, targetGO);
                }

                if (targetIndex < 0) targetIndex = 0;
                int finalIndex = (mode == DragDropMode.InsertBefore) ? targetIndex : targetIndex + 1;

                // clamp finalIndex
                int maxIndex = (targetParent != null) ? targetParent.childCount : GetSceneRoots().Length;
                finalIndex = Mathf.Clamp(finalIndex, 0, maxIndex);

                draggedGO.transform.SetSiblingIndex(finalIndex);
            }
        }

        if (prefabStage != null)
        {
            try
            {
                EditorSceneManager.MarkSceneDirty(prefabStage.scene);
            }
            catch
            {
            }
        }
        else
        {
            EditorSceneManager.MarkSceneDirty(EditorSceneManager.GetActiveScene());
        }

        RebuildTree();
    }

    GameObject[] GetSiblings(Transform parent)
    {
        if (parent == null) return new GameObject[0];
        var arr = new GameObject[parent.childCount];
        for (int i = 0; i < parent.childCount; ++i) arr[i] = parent.GetChild(i).gameObject;
        return arr;
    }

    GameObject[] GetSceneRoots()
    {
        var roots = EditorSceneManager.GetActiveScene().GetRootGameObjects();
        return roots;
    }

    bool IsAncestor(Transform potentialChild, Transform potentialAncestor)
    {
        if (potentialChild == null || potentialAncestor == null) return false;
        var t = potentialAncestor;
        while (t != null)
        {
            if (t == potentialChild) return true;
            t = t.parent;
        }

        return false;
    }

    Texture GetObjectIcon(GameObject go)
    {
        try
        {
            if (PrefabUtility.IsPartOfAnyPrefab(go))
            {
                var prefabAsset = PrefabUtility.GetCorrespondingObjectFromSource(go);
                if (prefabAsset != null) return EditorGUIUtility.ObjectContent(prefabAsset, typeof(GameObject)).image;
            }
        }
        catch
        {
        }

        return EditorGUIUtility.ObjectContent(go, typeof(GameObject)).image;
    }

    void UpdateSelectionHighlighting()
    {
        var rows = treeContainer.Query<VisualElement>(className: "uxh-row").ToList();
        foreach (var r in rows)
        {
            var go = r.parent.userData as GameObject;
            if (go != null && selectedObjects.Contains(go))
            {
                r.style.backgroundColor = new StyleColor(new Color(0.24f, 0.48f, 0.78f, 0.18f));
            }
            else
            {
                r.style.backgroundColor = new StyleColor(Color.clear);
            }
        }
    }

    void SelectSingle(GameObject go)
    {
        selectedObjects = new List<GameObject> { go };
        Selection.objects = selectedObjects.ToArray();
        UpdateSelectionHighlighting();
    }

    void OnKeyDown(KeyDownEvent evt)
    {
        if (evt.keyCode == KeyCode.Delete || evt.keyCode == KeyCode.Backspace)
        {
            deleteKeyHeld = true;
            nextAutoDeleteTime = EditorApplication.timeSinceStartup + DeleteInitialDelay;
            DoDeleteSelected();
            evt.StopImmediatePropagation();
            return;
        }

        if (evt.keyCode == KeyCode.F2)
        {
            // ensure F2 triggers rename even if UI focus is elsewhere
            if (Selection.activeGameObject != null)
                StartRenameFor(Selection.activeGameObject);
            evt.StopImmediatePropagation();
            return;
        }

        if ((evt.ctrlKey || evt.commandKey) && evt.keyCode == KeyCode.A)
        {
            selectedObjects = flatList.Where(x => x != null).ToList();
            Selection.objects = selectedObjects.ToArray();
            UpdateSelectionHighlighting();
            evt.StopImmediatePropagation();
            return;
        }

        if ((evt.ctrlKey || evt.commandKey) && evt.keyCode == KeyCode.D)
        {
            DuplicateSelected();
            evt.StopImmediatePropagation();
            return;
        }
    }

    void OnKeyUp(KeyUpEvent evt)
    {
        if (evt.keyCode == KeyCode.Delete || evt.keyCode == KeyCode.Backspace)
        {
            deleteKeyHeld = false;
            evt.StopImmediatePropagation();
            return;
        }
    }

    // also catch F2 and Delete in IMGUI OnGUI (helps when UI Toolkit root doesn't have keyboard focus)
    void OnGUI()
    {
        var e = Event.current;
        if (e.type == EventType.KeyDown)
        {
            if (e.keyCode == KeyCode.F2)
            {
                if (Selection.activeGameObject != null)
                {
                    StartRenameFor(Selection.activeGameObject);
                    e.Use();
                }
            }
            else if (e.keyCode == KeyCode.Delete || e.keyCode == KeyCode.Backspace)
            {
                DoDeleteSelected();
                e.Use();
            }
            else if ((e.control || e.command) && e.keyCode == KeyCode.D)
            {
                DuplicateSelected();
                e.Use();
            }
        }
    }

    void DuplicateSelected()
    {
        if (selectedObjects == null || selectedObjects.Count == 0) return;

        var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
        Transform rootPrefab = (prefabStage != null && prefabStage.prefabContentsRoot != null)
            ? prefabStage.prefabContentsRoot.transform
            : null;

        // 收集有效的原对象（排除 null）
        var originals = selectedObjects.Where(x => x != null).ToList();
        if (originals.Count == 0) return;

        // 按 parent 分组，这样可以为每个 parent 保持插入索引逻辑
        var grouped = originals.GroupBy(go => go.transform.parent);

        List<GameObject> newSelections = new List<GameObject>();

        foreach (var grp in grouped)
        {
            Transform parent = grp.Key; // 可能为 null（场景根）
            // 按 sibling index 升序处理，避免插入时索引错乱
            var items = grp.OrderBy(g => g.transform.GetSiblingIndex()).ToList();
            int insertedCount = 0;

            foreach (var original in items)
            {
                if (original == null) continue;
                // 不要复制 prefab contents root 本身
                if (rootPrefab != null && original == rootPrefab.gameObject) continue;

                // 实例化（会复制子物体和所有组件的当前值）
                GameObject dup = (GameObject)Object.Instantiate(original);

                // 让名字在同父级下唯一（简单实现），避免大量 "(Clone)" 风格名字
                dup.name = GetUniqueNameInParent(original.name, parent);

                // 注册 Undo（便于撤销）
                Undo.RegisterCreatedObjectUndo(dup, "Duplicate GameObject (UXHierarchy)");

                // 设置 parent & sibling index （使用 SetParent(false) 保持本地变换）
                if (parent != null)
                {
                    dup.transform.SetParent(parent, false);
                    int origIndex = original.transform.GetSiblingIndex();
                    int finalIndex = Mathf.Clamp(origIndex + 1 + insertedCount, 0, parent.childCount - 1);
                    dup.transform.SetSiblingIndex(finalIndex);
                }
                else
                {
                    // 场景根
                    dup.transform.SetParent(null);
                    int origIndex = original.transform.GetSiblingIndex();
                    int finalIndex = Mathf.Clamp(origIndex + 1 + insertedCount, 0, GetSceneRoots().Length - 1);
                    dup.transform.SetSiblingIndex(finalIndex);
                }

                newSelections.Add(dup);
                insertedCount++;
            }
        }

        // 把 Selection 设置为新复制的对象
        Selection.objects = newSelections.Cast<Object>().ToArray();
        selectedObjects = newSelections;

        // 标记脏并刷新树视图
        if (prefabStage != null)
        {
            try
            {
                EditorSceneManager.MarkSceneDirty(prefabStage.scene);
            }
            catch
            {
            }
        }
        else
        {
            EditorSceneManager.MarkSceneDirty(EditorSceneManager.GetActiveScene());
        }

        RebuildTree();
        UpdateSelectionHighlighting();
        Repaint();
    }

// 简单的在父级中创建不同名的方法（避免与同名 sibling 冲突）
    string GetUniqueNameInParent(string baseName, Transform parent)
    {
        GameObject[] siblings = parent != null ? GetSiblings(parent) : GetSceneRoots();
        string name = baseName;
        int suffix = 1;
        // 如果已存在相同名字，则追加 " 1", " 2" ...（你可以改成其它命名规则）
        while (siblings.Any(g => g != null && g.name == name))
        {
            name = baseName + " " + suffix;
            suffix++;
        }

        return name;
    }

    void DoDeleteSelected()
    {
        if (selectedObjects == null || selectedObjects.Count == 0) return;

        if (selectedObjects.Count > 10)
        {
            if (!EditorUtility.DisplayDialog("Delete objects", $"Delete {selectedObjects.Count} objects?", "Delete", "Cancel"))
                return;
        }

        var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
        var rootPrefab = prefabStage.prefabContentsRoot;

        foreach (var go in selectedObjects.ToArray())
        {
            if (go == null) continue;
            if (rootPrefab == go)
            {
                Debug.Log("Component Root Node Can Not Delete");
                continue;
            }

            Undo.DestroyObjectImmediate(go);
        }

        selectedObjects.Clear();
        Selection.objects = new Object[0];

        if (prefabStage != null)
        {
            try
            {
                EditorSceneManager.MarkSceneDirty(prefabStage.scene);
            }
            catch
            {
            }
        }
        else
        {
            EditorSceneManager.MarkSceneDirty(EditorSceneManager.GetActiveScene());
        }

        RebuildTree();
    }

    void StartRenameFor(GameObject go)
    {
        if (go == null) return;
        var nodes = treeContainer.Query<VisualElement>().Where(n => n.userData == go).ToList();
        if (nodes.Count > 0)
        {
            var node = nodes[0];
            var row = node.ElementAt(0);
            // find the label child (not other labels)
            Label label = null;
            foreach (var child in row.Children())
            {
                if (child is Label l && l.userData is int)
                {
                    label = l;
                    break;
                }
            }

            if (label != null) StartRename(row, go, label);
            else Debug.LogWarning("UXHierarchy: cannot find label to rename.");
        }
    }

    void StartRename(VisualElement row, GameObject go, Label label)
    {
        StopRename();

        var tf = new TextField();
        tf.value = go.name;
        tf.style.flexGrow = 1;
        tf.style.marginLeft = 0;
        tf.style.marginRight = 0;

        int idx = row.IndexOf(label);
        if (idx >= 0)
        {
            row.Remove(label);
            row.Insert(idx, tf);
            tf.Focus();
            tf.SelectAll();
            activeRenameField = tf;

            tf.RegisterCallback<KeyDownEvent>(evt =>
            {
                if (evt.keyCode == KeyCode.Return || evt.keyCode == KeyCode.KeypadEnter)
                {
                    CommitRename(go, tf.value);
                    evt.StopImmediatePropagation();
                }
                else if (evt.keyCode == KeyCode.Escape)
                {
                    CancelRename(row, tf, label);
                    evt.StopImmediatePropagation();
                }
            });

            tf.RegisterCallback<FocusOutEvent>(evt => { CommitRename(go, tf.value); });
        }
    }

    void CommitRename(GameObject go, string newName)
    {
        if (go == null) return;
        if (newName == go.name)
        {
            StopRename();
            return;
        }

        Undo.RecordObject(go, "Rename GameObject (UXHierarchy)");
        go.name = newName;
        EditorUtility.SetDirty(go);
        StopRename();

        var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
        if (prefabStage != null)
        {
            try
            {
                EditorSceneManager.MarkSceneDirty(prefabStage.scene);
            }
            catch
            {
            }
        }

        RebuildTree();
    }

    void CancelRename(VisualElement row, TextField tf, Label label)
    {
        int idx = row.IndexOf(tf);
        if (idx >= 0)
        {
            row.Remove(tf);
            row.Insert(idx, label);
        }

        activeRenameField = null;
    }

    void StopRename()
    {
        if (activeRenameField == null) return;
        var tf = activeRenameField;
        var parent = tf.parent;
        if (parent != null)
        {
            var label = new Label(tf.value);
            label.style.flexGrow = 1;
            int idx = parent.IndexOf(tf);
            parent.Remove(tf);
            parent.Insert(idx, label);
        }

        activeRenameField = null;
    }

    // New: create empty UI GameObject with RectTransform. If parentGO is null, create at root or prefab root
    void CreateEmptyUI(GameObject parentGO)
    {
        var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
        Transform parentTransform = null;
        if (parentGO != null)
            parentTransform = parentGO.transform;
        else if (prefabStage != null && prefabStage.prefabContentsRoot != null)
            parentTransform = prefabStage.prefabContentsRoot.transform;
        else
            parentTransform = null; // scene root

        var go = new GameObject("New UI Empty", typeof(RectTransform));
        Undo.RegisterCreatedObjectUndo(go, "Create New UI Empty (UXHierarchy)");
        if (parentTransform != null)
        {
            go.transform.SetParent(parentTransform, false);
        }
        // else leave at scene root (transform.parent == null)

        Selection.activeGameObject = go;
        if (prefabStage != null)
        {
            try
            {
                EditorSceneManager.MarkSceneDirty(prefabStage.scene);
            }
            catch
            {
            }
        }
        else
        {
            EditorSceneManager.MarkSceneDirty(EditorSceneManager.GetActiveScene());
        }

        RebuildTree();
    }

    // fold state persistence keyed by context (prefab asset path or scene path)
    string GetFoldPrefsKey()
    {
        var prefabStage = PrefabStageUtility.GetCurrentPrefabStage();
        if (prefabStage != null)
        {
            var path = prefabStage.assetPath;
            if (string.IsNullOrEmpty(path)) path = "prefab_unknown";
            return $"{FoldoutPrefsKeyBase}::prefab::{path}";
        }
        else
        {
            var scene = EditorSceneManager.GetActiveScene();
            var sp = string.IsNullOrEmpty(scene.path) ? "scene_unsaved" : scene.path;
            return $"{FoldoutPrefsKeyBase}::scene::{sp}";
        }
    }

    void SaveFoldStates()
    {
        try
        {
            var entries = foldStates.Select(kv => $"{kv.Key}:{(kv.Value ? 1 : 0)}");
            var joined = string.Join(",", entries);
            EditorPrefs.SetString(GetFoldPrefsKey(), joined);
        }
        catch (Exception ex)
        {
            Debug.LogWarning("UXHierarchy could not save fold states: " + ex.Message);
        }
    }

    void LoadFoldStates()
    {
        foldStates.Clear();
        var key = GetFoldPrefsKey();
        if (EditorPrefs.HasKey(key))
        {
            var joined = EditorPrefs.GetString(key);
            if (!string.IsNullOrEmpty(joined))
            {
                try
                {
                    var parts = joined.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
                    foreach (var p in parts)
                    {
                        var kv = p.Split(':');
                        if (kv.Length == 2)
                        {
                            if (int.TryParse(kv[0], out int id) && int.TryParse(kv[1], out int v))
                            {
                                foldStates[id] = (v == 1);
                            }
                        }
                    }
                }
                catch
                {
                    foldStates.Clear();
                }
            }
        }
    }

    private void CreateCommonUIMenu(ContextualMenuPopulateEvent evt, GameObject target)
    {
        MenuCommand command = new MenuCommand(target);
        evt.menu.AppendSeparator();
        evt.menu.AppendAction("UXImage", a => { UXCreateHelper.CreateUXImage(command); }, a => DropdownMenuAction.Status.Normal);
        evt.menu.AppendAction("UXTextMeshPro", a => { UXCreateHelper.CreateUXTextMeshPro(command); }, a => DropdownMenuAction.Status.Normal);
        evt.menu.AppendAction("UXButton", a => { UXCreateHelper.CreateUXButton(command); }, a => DropdownMenuAction.Status.Normal);
        evt.menu.AppendAction("UXInput Field", a => { UXCreateHelper.CreateUXInputField(command); }, a => DropdownMenuAction.Status.Normal);
        evt.menu.AppendAction("UXScrollView", a => { UXCreateHelper.CreateUxRecyclerView(); }, a => DropdownMenuAction.Status.Normal);
    }

    private void CreateControlerUIMenu(ContextualMenuPopulateEvent evt, GameObject target)
    {
        evt.menu.AppendSeparator();
        evt.menu.AppendAction("添加控制器", a =>
        {
            if (!target.TryGetComponent(typeof(UXControllerStateRecorder), out Component controller))
            {
                target.AddComponent(typeof(UXControllerStateRecorder));
            }
        }, a => DropdownMenuAction.Status.Normal);
    }
}