using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using BaseGames.Core;
using BaseGames.Core.Assets;
using BaseGames.Core.Events;

namespace BaseGames.UI.MainMenu
{
    /// <summary>
    /// 数据驱动主菜单控制器（<see cref="MainMenuController"/> 的表驱动版，非破坏性并存）。
    ///
    /// 按钮列表据 <see cref="MainMenuConfigSO"/> 生成（标签/图标/顺序/动作纯数据，策划改表零代码）；
    /// 子面板开关、存档槽流程、入场动画、状态锁定等编排仍在本控制器（场景耦合，不下放配置表）。
    /// 动作派发：内置 NewGame/Continue/OpenSettings/OpenCredits/LoadScene/Quit + 事件频道 RaiseEvent。
    /// </summary>
    public class DataDrivenMainMenuController : MonoBehaviour
    {
        [Header("数据表 / 按钮列表")]
        [SerializeField] private MainMenuConfigSO   _config;
        [Tooltip("按钮的父节点（通常挂 VerticalLayoutGroup，即主按钮组）。")]
        [SerializeField] private Transform          _container;
        [SerializeField] private MainMenuButtonView _buttonPrefab;

        [Header("主按钮组（入场动画）")]
        [SerializeField] private CanvasGroup   _mainButtonsGroup;
        [SerializeField] private RectTransform _mainButtonsRect;

        [Header("子面板")]
        [SerializeField] private GameObject _saveSlotPanel;
        [SerializeField] private BaseGames.UI.Menus.SaveSlotController _saveSlotController;
        [SerializeField] private GameObject _settingsPanel;
        [SerializeField] private GameObject _creditsPanel;

        [Header("子面板关闭按钮（可选）")]
        [SerializeField] private Button _btnCloseSaveSlot;
        [SerializeField] private Button _btnCloseSettings;
        [SerializeField] private Button _btnCloseCredits;

        [Header("入场动画")]
        [SerializeField] private float _entrySlideOffset = 80f;
        [SerializeField] private float _entryDuration    = 0.55f;

        [Header("场景")]
        [SerializeField] private string _firstGameSceneKey = AddressKeys.SceneGameChapter1;

        [Header("Event Channels - Listen")]
        [SerializeField] private GameStateEventChannelSO _onGameStateChanged;
        [SerializeField] private IntEventChannelSO       _onSlotConfirmed;

        [Header("Event Channels - Raise")]
        [SerializeField] private SceneLoadRequestEventChannelSO _onSceneLoadRequest;

        private readonly CompositeDisposable _subs = new();
        private readonly List<(MainMenuConfigSO.Item item, MainMenuButtonView view)> _buttons = new();
        private Vector2 _buttonsPanelOriginalPos;
        private MainMenuButtonView _firstButton;

        // ── 生命周期 ──────────────────────────────────────────────────────────
        private void Awake()
        {
            if (_buttonPrefab != null) _buttonPrefab.gameObject.SetActive(false);

            _btnCloseSaveSlot?.onClick.AddListener(() => CloseSubPanel(_saveSlotPanel));
            _btnCloseSettings?.onClick.AddListener(() => CloseSubPanel(_settingsPanel));
            _btnCloseCredits? .onClick.AddListener(() => CloseSubPanel(_creditsPanel));

            if (_mainButtonsRect != null)
                _buttonsPanelOriginalPos = _mainButtonsRect.anchoredPosition;

            SetPanel(_saveSlotPanel, false);
            SetPanel(_settingsPanel, false);
            SetPanel(_creditsPanel,  false);
            SetButtonsGroupVisible(false);

            BuildMenu();
        }

        private void OnEnable()
        {
            _onGameStateChanged?.Subscribe(HandleGameStateChanged).AddTo(_subs);
            _onSlotConfirmed?   .Subscribe(HandleSlotConfirmed).AddTo(_subs);
        }

        private void OnDisable() => _subs.Clear();

        private void Start() => StartCoroutine(PlayEntryAnimation());

        // ── 据表建菜单 ────────────────────────────────────────────────────────
        /// <summary>据配置重建主菜单按钮列表（public 以便编辑器/测试验证）。</summary>
        public void BuildMenu()
        {
            foreach (var (_, view) in _buttons) if (view != null) Destroy(view.gameObject);
            _buttons.Clear();
            _firstButton = null;

            if (_config == null || _container == null || _buttonPrefab == null) return;

            foreach (var item in _config.Items)
            {
                var view = Instantiate(_buttonPrefab, _container);
                view.gameObject.SetActive(true);
                var captured = item;
                view.Bind(item.labelKey, item.icon, () => Dispatch(captured));
                _buttons.Add((item, view));
                if (_firstButton == null) _firstButton = view;
            }

            RefreshConditional();
        }

        /// <summary>根据存档存在性刷新 requiresSave 按钮的可用性（如"继续"）。</summary>
        public void RefreshConditional()
        {
            bool hasSave = HasAnySave();
            foreach (var (item, view) in _buttons)
                if (item.requiresSave && view != null)
                    view.SetInteractable(hasSave);
        }

        // ── 动作派发 ──────────────────────────────────────────────────────────
        private void Dispatch(MainMenuConfigSO.Item item)
        {
            switch (item.action)
            {
                case MainMenuAction.NewGame:
                    _saveSlotController?.SetMode(BaseGames.UI.Menus.SaveSlotPanelMode.NewGame);
                    OpenSubPanel(_saveSlotPanel);
                    break;
                case MainMenuAction.Continue:
                    _saveSlotController?.SetMode(BaseGames.UI.Menus.SaveSlotPanelMode.Continue);
                    OpenSubPanel(_saveSlotPanel);
                    break;
                case MainMenuAction.OpenSettings:
                    OpenSubPanel(_settingsPanel);
                    break;
                case MainMenuAction.OpenCredits:
                    OpenSubPanel(_creditsPanel);
                    if (_btnCloseCredits != null)
                        EventSystem.current?.SetSelectedGameObject(_btnCloseCredits.gameObject);
                    break;
                case MainMenuAction.LoadScene:
                    _onSceneLoadRequest?.Raise(new SceneLoadRequest
                    {
                        SceneName         = string.IsNullOrEmpty(item.sceneKey) ? _firstGameSceneKey : item.sceneKey,
                        TransitionType    = TransitionType.Scene,
                        ShowLoadingScreen = true,
                    });
                    break;
                case MainMenuAction.Quit:
                    Application.Quit();
                    break;
                case MainMenuAction.RaiseEvent:
                    item.eventChannel?.Raise();
                    break;
            }
        }

        // ── 子面板编排 ────────────────────────────────────────────────────────
        private void OpenSubPanel(GameObject panel)
        {
            SetMainButtonsInteractable(false);
            SetPanel(panel, true);
        }

        private void CloseSubPanel(GameObject panel)
        {
            SetPanel(panel, false);
            SetMainButtonsInteractable(true);
            if (_firstButton != null)
                EventSystem.current?.SetSelectedGameObject(_firstButton.Button.gameObject);
        }

        private void SetMainButtonsInteractable(bool on)
        {
            if (_mainButtonsGroup == null) return;
            _mainButtonsGroup.interactable   = on;
            _mainButtonsGroup.blocksRaycasts = on;
        }

        // ── 存档槽确认（与 MainMenuController 一致）────────────────────────────
        private void HandleSlotConfirmed(int _)
        {
            SetPanel(_saveSlotPanel, false);

            var svc = ServiceLocator.GetOrDefault<ISaveService>();
            string checkpointScene = svc?.LastCheckpointScene;
            bool   hasCheckpoint   = !string.IsNullOrEmpty(checkpointScene);

            _onSceneLoadRequest?.Raise(new SceneLoadRequest
            {
                SceneName         = hasCheckpoint ? checkpointScene : _firstGameSceneKey,
                EntryTransitionId = hasCheckpoint ? svc.LastCheckpointSpawnId : null,
                TransitionType    = TransitionType.Scene,
                ShowLoadingScreen = true,
            });
        }

        private void HandleGameStateChanged(GameStateId state)
        {
            bool isMainMenu = state == GameStates.MainMenu;
            if (_mainButtonsGroup != null)
            {
                _mainButtonsGroup.interactable   = isMainMenu;
                _mainButtonsGroup.blocksRaycasts = isMainMenu;
            }
        }

        // ── 入场动画 ──────────────────────────────────────────────────────────
        private IEnumerator PlayEntryAnimation()
        {
            if (_mainButtonsGroup == null) yield break;

            Vector2 startPos = _buttonsPanelOriginalPos - new Vector2(0f, _entrySlideOffset);
            if (_mainButtonsRect != null) _mainButtonsRect.anchoredPosition = startPos;

            float elapsed = 0f;
            while (elapsed < _entryDuration)
            {
                float t = Mathf.SmoothStep(0f, 1f, elapsed / _entryDuration);
                _mainButtonsGroup.alpha = t;
                if (_mainButtonsRect != null)
                    _mainButtonsRect.anchoredPosition = Vector2.Lerp(startPos, _buttonsPanelOriginalPos, t);
                elapsed += Time.unscaledDeltaTime;
                yield return null;
            }

            _mainButtonsGroup.alpha = 1f;
            if (_mainButtonsRect != null) _mainButtonsRect.anchoredPosition = _buttonsPanelOriginalPos;
            _mainButtonsGroup.interactable   = true;
            _mainButtonsGroup.blocksRaycasts = true;

            if (_firstButton != null)
                EventSystem.current?.SetSelectedGameObject(_firstButton.Button.gameObject);
        }

        // ── 工具 ──────────────────────────────────────────────────────────────
        private static bool HasAnySave()
        {
            var s = ServiceLocator.GetOrDefault<ISaveService>();
            return s != null && (s.HasSave(0) || s.HasSave(1) || s.HasSave(2));
        }

        private static void SetPanel(GameObject panel, bool active)
        {
            if (panel != null) panel.SetActive(active);
        }

        private void SetButtonsGroupVisible(bool visible)
        {
            if (_mainButtonsGroup == null) return;
            _mainButtonsGroup.alpha          = visible ? 1f : 0f;
            _mainButtonsGroup.interactable   = visible;
            _mainButtonsGroup.blocksRaycasts = visible;
        }
    }
}