using System.Collections.Generic;
using System.IO;
using System.Linq;
using AibisDream;
using UnityEditor;
using UnityEditor.UIElements;
using UnityEngine;
using UnityEngine.UIElements;

namespace AibisDream.SystemEditor
{
    public class ChapterGraphEditorWindow : EditorWindow
    {
        private ChapterGraphView _graphView;
        private ChapterGraphInspector _inspector;
        private IMGUIContainer _inspectorContainer;

        private const string RootFolderPrefKey = "AibisDream.ChapterGraph.RootFolder";
        private const string CurrentFolderPrefKey = "AibisDream.ChapterGraph.CurrentFolder";
        private string _rootFolder;
        private string _currentFolder;
        private DropdownField _folderDropdown;
        private readonly Dictionary<string, string> _displayToPath = new();

        [MenuItem(AibisEditorMenus.ChapterGraphEditor)]
        public static void ShowWindow()
        {
            var window = GetWindow<ChapterGraphEditorWindow>("Chapter Graph Editor");
            window.minSize = new Vector2(800, 600);
        }

        private void OnEnable()
        {
            if (_graphView == null) return;
            _graphView.LoadGraph(_currentFolder);
        }

        private void OnDisable()
        {
            if (_graphView != null)
            {
                _graphView.OnNodeDeleted -= OnNodeDeleted;
            }
            if (_inspector != null)
            {
                _inspector.OnColorChanged -= OnNodeColorChanged;
                _inspector.Destroy();
            }
        }

        private void CreateGUI()
        {
            // 根容器：纵向排列
            var root = rootVisualElement;
            root.style.flexDirection = FlexDirection.Column;

            // 顶部工具栏
            var toolbar = new Toolbar();
            toolbar.Add(CreateToolbarButton("Save", OnSaveClicked));
            toolbar.Add(CreateToolbarButton("Auto Layout", OnAutoLayoutClicked));
            toolbar.Add(CreateToolbarButton("Validate", OnValidateClicked));

            _rootFolder = EditorPrefs.GetString(RootFolderPrefKey, "Assets/ScriptableObjects/SceneSO");

            _folderDropdown = new DropdownField("路径");
            _folderDropdown.style.width = 160;
            _folderDropdown.style.marginLeft = 8;
            _folderDropdown.style.marginRight = 4;
            RefreshFolderChoices();
            _folderDropdown.RegisterValueChangedCallback(OnFolderChanged);
            toolbar.Add(_folderDropdown);

            var setRootBtn = new Button(OnSetRootFolderClicked) { text = "..." };
            setRootBtn.style.width = 28;
            toolbar.Add(setRootBtn);

            toolbar.Add(new ToolbarSpacer() { style = { flexGrow = 1 } });
            toolbar.Add(CreateToolbarButton("Create Chapter", OnCreateChapterClicked));
            root.Add(toolbar);

            // 主内容区：横向分栏
            var mainContainer = new VisualElement();
            mainContainer.style.flexGrow = 1;
            mainContainer.style.flexDirection = FlexDirection.Row;
            mainContainer.style.overflow = Overflow.Hidden;

            // 左侧 Inspector 面板
            var leftPanel = new VisualElement();
            leftPanel.style.width = 320;
            leftPanel.style.minWidth = 200;
            leftPanel.style.maxWidth = 500;
            leftPanel.style.flexShrink = 0;
            leftPanel.style.flexDirection = FlexDirection.Column;
            leftPanel.style.borderRightWidth = 1;
            leftPanel.style.borderRightColor = new StyleColor(new Color(0.15f, 0.15f, 0.15f));

            // Inspector 标题
            var header = new Label("章节属性")
            {
                style =
                {
                    unityFontStyleAndWeight = FontStyle.Bold,
                    fontSize = 14,
                    paddingTop = 8,
                    paddingBottom = 8,
                    paddingLeft = 12,
                    paddingRight = 12,
                    borderBottomWidth = 1,
                    borderBottomColor = new StyleColor(new Color(0.15f, 0.15f, 0.15f))
                }
            };
            leftPanel.Add(header);

            // IMGUI Inspector
            _inspector = new ChapterGraphInspector();
            _inspectorContainer = new IMGUIContainer(() => _inspector.OnGUI());
            _inspectorContainer.style.flexGrow = 1;
            leftPanel.Add(_inspectorContainer);

            mainContainer.Add(leftPanel);

            // 拖拽条
            var resizer = new VisualElement();
            resizer.style.width = 5;
            resizer.style.backgroundColor = new StyleColor(new Color(0.15f, 0.15f, 0.15f));
            mainContainer.Add(resizer);

            float startWidth = 0;
            float startMouseX = 0;
            resizer.RegisterCallback<MouseDownEvent>(evt =>
            {
                startWidth = leftPanel.resolvedStyle.width;
                startMouseX = evt.mousePosition.x;
                resizer.CaptureMouse();
                evt.StopPropagation();
            });
            resizer.RegisterCallback<MouseMoveEvent>(evt =>
            {
                if (!resizer.HasMouseCapture()) return;
                var delta = evt.mousePosition.x - startMouseX;
                var newWidth = Mathf.Clamp(startWidth + delta, 200, 600);
                leftPanel.style.width = newWidth;
            });
            resizer.RegisterCallback<MouseUpEvent>(evt =>
            {
                if (resizer.HasMouseCapture())
                    resizer.ReleaseMouse();
            });

            // 右侧 GraphView
            // 套一层容器：GraphView 与左侧 Inspector 并列放在 Flex Row 中时，
            // 内置 RectangleSelector 绘制的框选矩形会出现坐标偏移（已知 Unity 问题）。
            // 将 GraphView 放在独立的 Flex 子容器中可使其局部原点与父容器对齐，规避该偏移。
            var graphViewWrapper = new VisualElement();
            graphViewWrapper.style.flexGrow = 1;
            graphViewWrapper.style.flexDirection = FlexDirection.Column;
            graphViewWrapper.style.overflow = Overflow.Hidden;

            _graphView = new ChapterGraphView();
            _graphView.style.flexGrow = 1;
            graphViewWrapper.Add(_graphView);

            mainContainer.Add(graphViewWrapper);

            root.Add(mainContainer);

            // 加载图数据
            _graphView.LoadGraph(_currentFolder);

            // 选中节点同步到 Inspector
            _graphView.OnNodeSelected += OnNodeSelected;
            _graphView.OnNodeDeleted += OnNodeDeleted;
            _inspector.OnColorChanged += OnNodeColorChanged;
        }

        private void OnNodeDeleted(TalkSceneSO so)
        {
            _inspector?.SetTarget(null);
            _inspectorContainer?.MarkDirtyRepaint();
        }

        private void OnNodeColorChanged(TalkSceneSO so)
        {
            _graphView?.UpdateNodeColor(so);
        }

        private Button CreateToolbarButton(string text, System.Action onClick)
        {
            var btn = new Button(onClick) { text = text };
            return btn;
        }

        private void OnSaveClicked()
        {
            AssetDatabase.SaveAssets();
            EditorUtility.DisplayDialog("保存", "所有资源已保存。", "确定");
        }

        private void OnAutoLayoutClicked()
        {
            _graphView?.AutoLayout();
        }

        private void OnValidateClicked()
        {
            _graphView?.ValidateGraph();
        }

        private void OnCreateChapterClicked()
        {
            var center = new Vector2(position.width / 2f, position.height / 2f);
            var localPos = _graphView.contentViewContainer.WorldToLocal(center);
            var defaultFolder = _currentFolder ?? EditorPrefs.GetString(ChapterGraphView.DefaultFolderPrefKey, _rootFolder);
            _graphView?.CreateChapterNodeAt(localPos, defaultFolder);
        }

        private void OnNodeSelected(TalkSceneSO so)
        {
            _inspector?.SetTarget(so);
            _inspectorContainer?.MarkDirtyRepaint();
        }

        private void RefreshFolderChoices()
        {
            _displayToPath.Clear();
            _displayToPath["All"] = null;

            var subFolders = AssetDatabase.GetSubFolders(_rootFolder);
            foreach (var folder in subFolders)
            {
                var name = Path.GetFileName(folder);
                _displayToPath[name] = folder;
            }

            var rootHasSO = AssetDatabase.FindAssets("t:TalkSceneSO", new[] { _rootFolder })
                .Select(g => AssetDatabase.GUIDToAssetPath(g))
                .Any(path => Path.GetDirectoryName(path)?.Replace('\\', '/') == _rootFolder);

            if (rootHasSO)
            {
                _displayToPath["(Root)"] = _rootFolder;
            }

            _folderDropdown.choices = _displayToPath.Keys.ToList();

            var saved = EditorPrefs.GetString(CurrentFolderPrefKey, "All");
            _folderDropdown.value = _displayToPath.ContainsKey(saved) ? saved : "All";
            _currentFolder = _displayToPath.TryGetValue(_folderDropdown.value, out var path) ? path : null;
        }

        private void OnFolderChanged(ChangeEvent<string> evt)
        {
            _currentFolder = _displayToPath.TryGetValue(evt.newValue, out var path) ? path : null;
            EditorPrefs.SetString(CurrentFolderPrefKey, evt.newValue);
            _graphView?.LoadGraph(_currentFolder);
        }

        private void OnSetRootFolderClicked()
        {
            var path = EditorUtility.OpenFolderPanel("选择章节根目录", _rootFolder, "");
            if (string.IsNullOrEmpty(path)) return;

            var absoluteRoot = Application.dataPath.Replace('\\', '/');
            var selected = path.Replace('\\', '/');
            if (!selected.StartsWith(absoluteRoot))
            {
                EditorUtility.DisplayDialog("错误", "请选择项目 Assets 目录内的文件夹。", "确定");
                return;
            }

            _rootFolder = "Assets" + selected.Substring(absoluteRoot.Length);
            EditorPrefs.SetString(RootFolderPrefKey, _rootFolder);
            RefreshFolderChoices();
            _graphView?.LoadGraph(_currentFolder);
        }
    }
}