using UnityEngine;
using UnityEditor;
using UnityEngine.UIElements;
using UnityEditor.UIElements;

[CustomEditor(typeof(ItemController))]
public class ItemControllerEditor : Editor
{
    private const string UxmlPath = "Assets/Scripts/Streamingle/StreamingleControl/Editor/UXML/ItemControllerEditor.uxml";
    private const string CommonUssPath = "Assets/Scripts/Streamingle/StreamingleControl/Editor/UXML/StreamingleCommon.uss";

    private VisualElement itemsContainer;
    private Label itemsTitleLabel;
    private ItemController controller;

    public override VisualElement CreateInspectorGUI()
    {
        controller = (ItemController)target;
        var root = new VisualElement();

        var commonUss = AssetDatabase.LoadAssetAtPath<StyleSheet>(CommonUssPath);
        if (commonUss != null) root.styleSheets.Add(commonUss);

        var uxml = AssetDatabase.LoadAssetAtPath<VisualTreeAsset>(UxmlPath);
        if (uxml != null) uxml.CloneTree(root);

        BuildItemGroupsSection(root);

        root.schedule.Execute(UpdatePlayModeState).Every(200);

        Undo.undoRedoPerformed += OnUndoRedo;
        root.RegisterCallback<DetachFromPanelEvent>(_ => Undo.undoRedoPerformed -= OnUndoRedo);

        return root;
    }

    private void OnUndoRedo()
    {
        if (controller == null) return;
        serializedObject.Update();
        RebuildItemList();
    }

    #region Item Groups List

    private void BuildItemGroupsSection(VisualElement root)
    {
        var section = root.Q("itemGroupsSection");
        if (section == null) return;

        var header = new VisualElement();
        header.AddToClassList("list-header");

        itemsTitleLabel = new Label($"Item Groups ({controller.itemGroups.Count})");
        itemsTitleLabel.AddToClassList("list-title");
        header.Add(itemsTitleLabel);

        var addBtn = new Button(AddItemGroup) { text = "+ 그룹 추가" };
        addBtn.AddToClassList("list-add-btn");
        header.Add(addBtn);

        section.Add(header);

        itemsContainer = new VisualElement();
        section.Add(itemsContainer);

        RebuildItemList();
    }

    private void RebuildItemList()
    {
        if (itemsContainer == null || controller == null) return;
        itemsContainer.Clear();

        if (itemsTitleLabel != null)
            itemsTitleLabel.text = $"Item Groups ({controller.itemGroups.Count})";

        if (controller.itemGroups.Count == 0)
        {
            var empty = new Label("아이템 그룹이 없습니다. '+ 그룹 추가' 버튼을 눌러 추가하세요.");
            empty.AddToClassList("list-empty");
            itemsContainer.Add(empty);
            return;
        }

        for (int i = 0; i < controller.itemGroups.Count; i++)
        {
            itemsContainer.Add(CreateItemGroupElement(i));
        }
    }

    private VisualElement CreateItemGroupElement(int index)
    {
        var group = controller.itemGroups[index];
        bool isActive = Application.isPlaying && group.IsActive();

        var item = new VisualElement();
        item.AddToClassList("list-item");
        if (isActive) item.AddToClassList("list-item--active");

        // Header row
        var headerRow = new VisualElement();
        headerRow.AddToClassList("list-item-header");

        var indexLabel = new Label($"{index + 1}");
        indexLabel.AddToClassList("list-index");
        headerRow.Add(indexLabel);

        var nameField = new TextField();
        nameField.value = group.groupName;
        nameField.AddToClassList("list-name-field");
        int idx = index;
        nameField.RegisterValueChangedCallback(evt =>
        {
            Undo.RecordObject(target, "Rename Item Group");
            controller.itemGroups[idx].groupName = evt.newValue;
            EditorUtility.SetDirty(target);
        });
        headerRow.Add(nameField);

        if (isActive)
        {
            var activeLabel = new Label("[Active]");
            activeLabel.AddToClassList("list-active-label");
            headerRow.Add(activeLabel);
        }

        // Reorder buttons
        var upBtn = new Button(() => SwapItems(idx, idx - 1)) { text = "\u25B2" };
        upBtn.AddToClassList("list-reorder-btn");
        upBtn.SetEnabled(index > 0);
        headerRow.Add(upBtn);

        var downBtn = new Button(() => SwapItems(idx, idx + 1)) { text = "\u25BC" };
        downBtn.AddToClassList("list-reorder-btn");
        downBtn.SetEnabled(index < controller.itemGroups.Count - 1);
        headerRow.Add(downBtn);

        var deleteBtn = new Button(() => DeleteItem(idx)) { text = "X" };
        deleteBtn.AddToClassList("list-delete-btn");
        headerRow.Add(deleteBtn);

        item.Add(headerRow);

        // Fields
        var fields = new VisualElement();
        fields.AddToClassList("list-fields");

        var listProp = serializedObject.FindProperty("itemGroups");
        var elementProp = listProp.GetArrayElementAtIndex(index);

        var objectsField = new PropertyField(elementProp.FindPropertyRelative("itemObjects"), "Objects");
        fields.Add(objectsField);

        item.Add(fields);
        return item;
    }

    private void AddItemGroup()
    {
        Undo.RecordObject(target, "Add Item Group");
        controller.itemGroups.Add(new ItemController.ItemGroup("New Item Group"));
        EditorUtility.SetDirty(target);
        serializedObject.Update();
        RebuildItemList();
    }

    private void DeleteItem(int index)
    {
        var group = controller.itemGroups[index];
        if (EditorUtility.DisplayDialog("그룹 삭제",
            $"그룹 '{group.groupName}'을(를) 삭제하시겠습니까?", "삭제", "취소"))
        {
            Undo.RecordObject(target, "Delete Item Group");
            controller.itemGroups.RemoveAt(index);
            EditorUtility.SetDirty(target);
            serializedObject.Update();
            RebuildItemList();
        }
    }

    private void SwapItems(int a, int b)
    {
        Undo.RecordObject(target, "Reorder Item Groups");
        (controller.itemGroups[a], controller.itemGroups[b]) = (controller.itemGroups[b], controller.itemGroups[a]);
        EditorUtility.SetDirty(target);
        serializedObject.Update();
        RebuildItemList();
    }

    #endregion

    #region Play Mode State

    private void UpdatePlayModeState()
    {
        if (itemsContainer == null || controller == null) return;
        if (!Application.isPlaying) return;

        for (int i = 0; i < itemsContainer.childCount && i < controller.itemGroups.Count; i++)
        {
            var item = itemsContainer[i];
            bool isActive = controller.itemGroups[i].IsActive();

            if (isActive && !item.ClassListContains("list-item--active"))
                item.AddToClassList("list-item--active");
            else if (!isActive && item.ClassListContains("list-item--active"))
                item.RemoveFromClassList("list-item--active");
        }
    }

    #endregion
}