using System.Collections.Generic;
using System.Linq;
using UnityEngine;
using BaseGames.Core;
using BaseGames.Core.Events;
using BaseGames.Core.Save;

namespace BaseGames.World.Map
{
    /// <summary>
    /// 运行时地图管理器（架构 15_MapShopModule §1.2）。
    /// 挂在 Persistent 场景 [GameManagers] 下，通过事件驱动记录已探索/已完整地图的房间。
    /// 实现 ISaveable 持久化探索进度。
    /// </summary>
    [DefaultExecutionOrder(-700)]
    public class MapManager : MonoBehaviour, ISaveable, IMapService
    {
        [SerializeField] private MapDatabaseSO _database;

        [Header("Event Channels")]
        [SerializeField] private StringEventChannelSO _onRoomEntered;   // 订阅 EVT_RoomEntered
        [SerializeField] private StringEventChannelSO _onMapUpdated;    // 发布：房间发现时
        [SerializeField] private StringEventChannelSO _onRegionChanged; // 发布：玩家首次进入新区域时（EVT_RegionChanged）

        // 三级可见性：
        //   Unknown  → 未进入过（默认）
        //   Explored → 进入过（显示轮廓/格子）
        //   Mapped   → 完整地图信息（购买 MapFragment 或存档点揭示）
        private HashSet<string> _exploredRooms = new();
        private HashSet<string> _mappedRooms   = new();
        private string          _currentRegionId;
        private readonly CompositeDisposable _subs = new();

        private void Awake()
        {
            if (ServiceLocator.GetOrDefault<IMapService>() != null) { Destroy(gameObject); return; }
            ServiceLocator.Register<IMapService>(this);
        }

        private void OnEnable()
        {
            _onRoomEntered?.Subscribe(OnRoomEntered).AddTo(_subs);
            ServiceLocator.GetOrDefault<ISaveableRegistry>()?.Register(this);
        }

        private void OnDisable()
        {
            _subs.Clear();
            ServiceLocator.GetOrDefault<ISaveableRegistry>()?.Unregister(this);
        }

        // ── ISaveable ─────────────────────────────────────────────────────────

        public void OnSave(SaveData data)
        {
            data.Map.ExploredRooms ??= new List<string>();
            data.Map.ExploredRooms.Clear();
            data.Map.ExploredRooms.AddRange(_exploredRooms);
            data.Map.MappedRooms ??= new List<string>();
            data.Map.MappedRooms.Clear();
            data.Map.MappedRooms.AddRange(_mappedRooms);
        }

        public void OnLoad(SaveData data)
        {
            _exploredRooms = new HashSet<string>(data.Map.ExploredRooms ?? new System.Collections.Generic.List<string>());
            _mappedRooms   = new HashSet<string>(data.Map.MappedRooms   ?? new System.Collections.Generic.List<string>());
        }

        // ── 事件驱动房间发现 ──────────────────────────────────────────────────

        private void OnRoomEntered(string roomId)
        {
            bool changed = _exploredRooms.Add(roomId);
            if (changed) _onMapUpdated?.Raise(roomId);

            // 区域变化检测：RegionId 非空且与上一次不同时广播 EVT_RegionChanged
            var regionId = _database?.GetRoom(roomId)?.RegionId;
            if (!string.IsNullOrEmpty(regionId) && regionId != _currentRegionId)
            {
                _currentRegionId = regionId;
                _onRegionChanged?.Raise(regionId);
            }
        }

        /// <summary>标记为已完整获取地图信息（购买 MapFragment SO 触发）。</summary>
        public void SetMapped(string roomId)
        {
            _exploredRooms.Add(roomId);
            if (_mappedRooms.Add(roomId))
                _onMapUpdated?.Raise(roomId);
        }

        // ── 查询 API ──────────────────────────────────────────────────────────

        public bool IsExplored(string roomId)   => _exploredRooms.Contains(roomId);
        public bool IsMapped(string roomId)     => _mappedRooms.Contains(roomId);
        public string CurrentRegionId           => _currentRegionId;

        public MapDatabaseSO Database => _database;

        private void OnDestroy()
        {
            ServiceLocator.Unregister<IMapService>(this);
        }
    }
}