using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;
using BaseGames.Editor.Modules;

namespace BaseGames.Editor
{
    /// <summary>
    /// 数据管理总枢纽窗口（DataHub）。
    /// 布局：导航侧边栏（120px） | TwoPaneSplitView → 列表区（220px） + 详情区（flex）。
    /// 菜单：BaseGames / Data Hub  (priority=50)
    /// </summary>
    public class DataHubWindow : EditorWindow
    {
        private const string UssPath      = "Assets/_Game/Scripts/Editor/UIToolkit/Editor.uss";
        private const string PrefKey      = "DataHub.ActiveModuleId";
        private const float  NavWidth     = 120f;
        private const float  ListWidth    = 220f;
        private const float  MinWinWidth  = 680f;
        private const float  MinWinHeight = 420f;

        [MenuItem("BaseGames/Data Hub", priority = 50)]
        public static void Open()
        {
            var wnd = GetWindow<DataHubWindow>();
            wnd.titleContent = new GUIContent("Data Hub", EditorGUIUtility.IconContent("d_ScriptableObject Icon").image);
            wnd.minSize = new Vector2(MinWinWidth, MinWinHeight);
        }

        // ── 状态 ─────────────────────────────────────────────────────────────

        private readonly List<IDataModule> _modules = new();
        private readonly HashSet<string>   _initializedIds = new();
        private IDataModule                _activeModule;

        private VisualElement _navSidebar;
        // NavBar 搜索：按 DisplayName 过滤可见模块
        private string        _navFilter = "";
        private readonly Dictionary<string, Button> _navButtons = new();

        // 缓存：列表区和详情区引用（由 TwoPaneSplitView 子节点提供）
        private VisualElement _listWrapper;
        private VisualElement _detailWrapper;

        // 当前选中资产
        private UnityEngine.Object _selected;

        // ── 生命周期 ──────────────────────────────────────────────────────────

        public void CreateGUI()
        {
            // USS
            var uss = AssetDatabase.LoadAssetAtPath<StyleSheet>(UssPath);
            if (uss != null) rootVisualElement.styleSheets.Add(uss);

            // 注册模块
            RegisterModules();

            // 构建 UI
            BuildLayout();

            // 恢复上次激活的模块
            string savedId = EditorPrefs.GetString(PrefKey, string.Empty);
            var toActivate = _modules.Find(m => m.ModuleId == savedId) ?? _modules.FirstOrDefault();
            if (toActivate != null) ActivateModule(toActivate);
        }

        // ── 模块注册 ──────────────────────────────────────────────────────────

        private void RegisterModules()
        {
            _modules.Clear();

            // 自动发现所有实现 IDataModule 的非抽象类型（排除接口/抽象类本身）
            // TypeCache 仅在 UnityEditor 中可用，零运行时开销
            var moduleTypes = UnityEditor.TypeCache.GetTypesDerivedFrom<IDataModule>();
            var instances   = new List<IDataModule>(moduleTypes.Count);
            foreach (var t in moduleTypes)
            {
                if (t.IsAbstract || t.IsInterface) continue;
                try { instances.Add((IDataModule)Activator.CreateInstance(t)); }
                catch (Exception ex)
                {
                    Debug.LogWarning($"[DataHubWindow] 无法实例化模块 {t.Name}: {ex.Message}");
                }
            }

            // 按 DisplayOrder 升序排列（若模块实现了 IDataModuleOrdered 则使用其值，否则默认 0）
            instances.Sort((a, b) =>
            {
                int oa = a is IDataModuleOrdered ao ? ao.DisplayOrder : 0;
                int ob = b is IDataModuleOrdered bo ? bo.DisplayOrder : 0;
                int c  = oa.CompareTo(ob);
                return c != 0 ? c : string.Compare(a.DisplayName, b.DisplayName, StringComparison.OrdinalIgnoreCase);
            });

            _modules.AddRange(instances);
        }

        // ── 布局 ─────────────────────────────────────────────────────────────

        private void BuildLayout()
        {
            var root = rootVisualElement;
            root.style.flexDirection = FlexDirection.Row;
            root.style.flexGrow      = 1;

            // 导航侧边栏
            _navSidebar = BuildNavSidebar();
            root.Add(_navSidebar);

            // 垂直分隔线
            var divider = new VisualElement();
            divider.style.width            = 1;
            divider.style.backgroundColor  = new StyleColor(new Color(0.5f, 0.5f, 0.5f, 0.25f));
            root.Add(divider);

            // TwoPaneSplitView（列表 + 详情）
            var split = new TwoPaneSplitView(0, ListWidth, TwoPaneSplitViewOrientation.Horizontal);
            split.style.flexGrow = 1;
            root.Add(split);

            // 列表区容器
            _listWrapper = new VisualElement();
            _listWrapper.style.flexGrow   = 1;
            _listWrapper.style.overflow   = Overflow.Hidden;
            split.Add(_listWrapper);

            // 详情区：外层 ScrollView 提供滚动视口，_detailWrapper 是内容容器（自然高度）
            var detailScroll = new ScrollView(ScrollViewMode.Vertical);
            detailScroll.style.flexGrow = 1;
            detailScroll.style.overflow = Overflow.Hidden;
            split.Add(detailScroll);

            _detailWrapper = new VisualElement();
            _detailWrapper.style.flexDirection = FlexDirection.Column;
            _detailWrapper.style.paddingBottom = 16;
            detailScroll.Add(_detailWrapper);
        }

        private VisualElement BuildNavSidebar()
        {
            var sidebar = new VisualElement();
            sidebar.style.width       = NavWidth;
            sidebar.style.flexShrink  = 0;
            sidebar.style.flexDirection = FlexDirection.Column;
            sidebar.style.paddingTop  = 8;

            // 标题
            var title = new Label("DATA HUB");
            title.style.fontSize    = 10;
            title.style.opacity     = 0.5f;
            title.style.paddingLeft = 10;
            title.style.marginBottom = 4;
            title.style.unityFontStyleAndWeight = FontStyle.Bold;
            sidebar.Add(title);

            // 搜索框
            var searchField = new TextField();
            searchField.style.marginLeft   = 6;
            searchField.style.marginRight  = 6;
            searchField.style.marginBottom = 6;
            searchField.tooltip = "按模块名称过滤";
            // 自定义占位符效果
            if (string.IsNullOrEmpty(searchField.value))
                searchField.value = "";
            searchField.RegisterValueChangedCallback(evt =>
            {
                _navFilter = evt.newValue ?? "";
                ApplyNavFilter();
            });
            sidebar.Add(searchField);

            _navButtons.Clear();
            foreach (var module in _modules)
            {
                var btn = BuildNavItem(module);
                _navButtons[module.ModuleId] = btn;
                sidebar.Add(btn);
            }

            // 弹性填充
            var spacer = new VisualElement();
            spacer.style.flexGrow = 1;
            sidebar.Add(spacer);

            return sidebar;
        }

        private void ApplyNavFilter()
        {
            foreach (var module in _modules)
            {
                if (!_navButtons.TryGetValue(module.ModuleId, out var btn)) continue;
                bool visible = string.IsNullOrEmpty(_navFilter) ||
                               module.DisplayName.IndexOf(_navFilter, System.StringComparison.OrdinalIgnoreCase) >= 0 ||
                               module.ModuleId.IndexOf(_navFilter, System.StringComparison.OrdinalIgnoreCase) >= 0;
                btn.style.display = visible ? DisplayStyle.Flex : DisplayStyle.None;
            }
        }

        private Button BuildNavItem(IDataModule module)
        {
            var btn = new Button(() => ActivateModule(module));
            btn.name = "nav-" + module.ModuleId;
            btn.style.flexDirection    = FlexDirection.Row;
            btn.style.alignItems       = Align.Center;
            btn.style.paddingLeft      = 10;
            btn.style.paddingRight     = 8;
            btn.style.paddingTop       = 8;
            btn.style.paddingBottom    = 8;
            btn.style.borderTopLeftRadius     = 0;
            btn.style.borderTopRightRadius    = 0;
            btn.style.borderBottomLeftRadius  = 0;
            btn.style.borderBottomRightRadius = 0;
            btn.style.borderLeftWidth   = 0;
            btn.style.borderRightWidth  = 0;
            btn.style.borderTopWidth    = 0;
            btn.style.borderBottomWidth = 0;
            btn.style.backgroundColor  = new StyleColor(Color.clear);
            btn.style.marginBottom     = 2;

            // 图标（容错：图标名无效时跳过，不报错）
            if (!string.IsNullOrEmpty(module.IconName))
            {
                var content = EditorGUIUtility.IconContent(module.IconName);
                if (content?.image != null)
                {
                    var icon = new Image { image = content.image };
                    icon.style.width       = 16;
                    icon.style.height      = 16;
                    icon.style.marginRight = 6;
                    btn.Add(icon);
                }
            }

            var label = new Label(module.DisplayName);
            label.style.flexGrow = 1;
            btn.Add(label);

            return btn;
        }

        // ── 模块切换 ──────────────────────────────────────────────────────────

        private void ActivateModule(IDataModule module)
        {
            if (_activeModule == module) return;
            _activeModule = module;
            _selected     = null;

            // 更新导航项视觉状态
            foreach (var m in _modules)
            {
                var navBtn = _navSidebar.Q<Button>("nav-" + m.ModuleId);
                if (navBtn == null) continue;

                if (m == module)
                {
                    navBtn.style.backgroundColor = new StyleColor(new Color(0.5f, 0.5f, 0.5f, 0.18f));
                    navBtn.style.borderLeftWidth = 3;
                    navBtn.style.borderLeftColor = new StyleColor(new Color(0.4f, 0.65f, 1f, 1f));
                }
                else
                {
                    navBtn.style.backgroundColor = new StyleColor(Color.clear);
                    navBtn.style.borderLeftWidth = 0;
                }
            }

            // 初始化模块（首次激活时调用一次）
            if (!_initializedIds.Contains(module.ModuleId))
            {
                _initializedIds.Add(module.ModuleId);
                module.Initialize();
            }
            module.OnActivated();

            // 重建列表区
            _listWrapper.Clear();
            module.BuildListPane(_listWrapper, OnModuleSelected);

            // 清空详情区
            RebuildDetailPane(null);

            EditorPrefs.SetString(PrefKey, module.ModuleId);
        }

        private void OnModuleSelected(UnityEngine.Object selected)
        {
            _selected = selected;
            RebuildDetailPane(selected);
        }

        private void RebuildDetailPane(UnityEngine.Object selected)
        {
            _detailWrapper.Clear();

            if (_activeModule == null) return;

            if (selected == null)
            {
                var placeholder = new Label("← 从左侧列表选择一项");
                placeholder.style.opacity   = 0.45f;
                placeholder.style.marginTop = 60;
                placeholder.style.unityTextAlign = TextAnchor.MiddleCenter;
                _detailWrapper.Add(placeholder);
                return;
            }

            _activeModule.BuildDetailPane(_detailWrapper, selected);
        }

        // ── 公共辅助（供 Module 回调使用）────────────────────────────────────

        /// <summary>通知 Hub 已完成重命名，需要刷新详情区标题。</summary>
        public void NotifyRenamed(UnityEngine.Object asset)
        {
            if (_activeModule == null || asset == null) return;
            RebuildDetailPane(asset);
        }
    }
}