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

namespace BaseGames.World.Map
{
    /// <summary>
    /// 全屏地图 UI 面板（架构 15_MapShopModule §1.3）。
    /// 由 UIManager PanelStack 管理开关；OnEnable 时重建格子并订阅更新事件。
    /// </summary>
    public class MapPanel : MonoBehaviour
    {
        [SerializeField] private MapDatabaseSO  _database;
        [SerializeField] private RectTransform  _roomContainer;     // 格子图放置根节点
        [SerializeField] private MapRoomCellUI  _cellPrefab;        // 地图格子预制

        [Header("图标 Sprites")]
        [SerializeField] private Sprite _iconSavePoint;
        [SerializeField] private Sprite _iconBossRoom;
        [SerializeField] private Sprite _iconShop;
        [SerializeField] private Sprite _iconPlayerPos;

        [Header("颜色")]
        [SerializeField] private Color _colorDiscovered   = Color.white;
        [SerializeField] private Color _colorUndiscovered = Color.black;

        [Header("Event Channels")]
        [SerializeField] private StringEventChannelSO _onMapUpdated;   // 房间发现时刷新

        private Dictionary<string, MapRoomCellUI> _cells = new();
        private readonly CompositeDisposable _subs = new();

        private void OnEnable()
        {
            // 首次打开时建立格子；后续打开只刷新探索状态，跳过 N 次 Instantiate
            if (_cells.Count == 0)
                BuildGrid();
            else
                RefreshAllCells();

            _onMapUpdated?.Subscribe(OnMapUpdated).AddTo(_subs);
        }

        private void OnDisable()
        {
            _subs.Clear();
            // 格子保留，不销毁——随面板 GameObject 一同隐藏
        }

        private void OnDestroy()
        {
            // 面板真正销毁时才清理格子
            foreach (var cell in _cells.Values)
                if (cell != null) Destroy(cell.gameObject);
            _cells.Clear();
        }

        // 面板重新打开时同步关闭期间积累的探索进度
        private void RefreshAllCells()
        {
            var mapManager = ServiceLocator.GetOrDefault<IMapService>();
            foreach (var (roomId, cell) in _cells)
            {
                if (cell == null) continue;
                bool discovered = mapManager != null && mapManager.IsExplored(roomId);
                cell.SetDiscovered(discovered);
            }
        }

        // ── 内部 ──────────────────────────────────────────────────────────────

        private void BuildGrid()
        {
            if (_database == null || _database.AllRooms == null) return;

            var mapManager = ServiceLocator.GetOrDefault<IMapService>();
            foreach (var room in _database.AllRooms)
            {
                if (room == null) continue;
                var cell = Instantiate(_cellPrefab, _roomContainer);
                bool discovered = mapManager != null && mapManager.IsExplored(room.RoomId);
                cell.Setup(room, discovered, ChooseIcon(room));
                _cells[room.RoomId] = cell;
            }
        }

        private void OnMapUpdated(string roomId)
        {
            if (_cells.TryGetValue(roomId, out var cell))
                cell.SetDiscovered(true);
        }

        private Sprite ChooseIcon(MapRoomDataSO room)
        {
            if (room.MapIconOverride != null) return room.MapIconOverride;
            if (room.IsSavePoint) return _iconSavePoint;
            if (room.IsBossRoom)  return _iconBossRoom;
            if (room.IsShop)      return _iconShop;
            return null;
        }
    }

    // ─── 单个地图格子 UI ─────────────────────────────────────────────────────────

    /// <summary>地图面板中每个房间对应的格子 UI 组件。</summary>
    public class MapRoomCellUI : MonoBehaviour
    {
        [SerializeField] private Image _bg;
        [SerializeField] private Image _icon;

        private static readonly Color Discovered   = Color.white;
        private static readonly Color Undiscovered = Color.black;

        /// <summary>初始化格子（位置、颜色、图标）。</summary>
        public void Setup(MapRoomDataSO room, bool discovered, Sprite icon)
        {
            // 根据 GridPosition/GridSize 设置 RectTransform 位置与大小
            if (TryGetComponent<RectTransform>(out var rt))
            {
                rt.anchoredPosition = new Vector2(
                    room.GridPosition.x * 32f,
                    room.GridPosition.y * 32f);
                rt.sizeDelta = new Vector2(
                    room.GridSize.x * 32f,
                    room.GridSize.y * 32f);
            }

            SetDiscovered(discovered);

            if (_icon != null)
            {
                _icon.sprite  = icon;
                _icon.enabled = icon != null;
            }
        }

        public void SetDiscovered(bool v)
        {
            if (_bg != null) _bg.color = v ? Discovered : Undiscovered;
        }
    }
}