using System;
using System.Collections.Generic;
using System.Linq;
using Base;
using Entity;
using Map;
using Prefab;
using UnityEngine;
using UnityEngine.SceneManagement;

namespace Managers
{
    
    public class EntityManage : Utils.MonoSingleton<EntityManage>, ITick
    {
        // --- 新增：维度感知的实体存储结构 ---
        // 外层字典：DimensionId -> 内层字典
        // 内层字典：FactionKey -> LinkedList<EntityPrefab>
        private Dictionary<string, Dictionary<string, LinkedList<EntityPrefab>>> _dimensionFactionEntities = new();

        // --- 新增：当前场景中活跃的维度实例 ---
        private Dictionary<string, Dimension> _activeDimensions = new();

        // --- 新增：维度感知的层级缓存 ---
        // DimensionId -> LayerName -> Transform
        private Dictionary<string, Dictionary<string, Transform>> _dimensionLayerCache = new();

        // --- 待添加实体列表，现在包含 DimensionId ---
        private List<Tuple<string, string, EntityPrefab>>
            _pendingAdditions = new(); // Item1: DimensionId, Item2: FactionKey, Item3: EntityPrefab

        // --- 现有预制体 (保持不变) ---
        public EntityPrefab characterPrefab;
        public EntityPrefab buildingPrefab;
        public EntityPrefab bulletPrefab;
        public EntityPrefab defaultEntityPrefab;

        public void RegisterDimension(Dimension dimension)
        {
            if (dimension == null || string.IsNullOrEmpty(dimension.DimensionId))
            {
                Debug.LogError("Attempted to register a null or invalid Dimension.");
                return;
            }

            if (_activeDimensions.TryGetValue(dimension.DimensionId, out var existingDimension))
            {
                if (existingDimension == dimension)
                {
                    // 【逻辑修改】如果是同一个实例重复注册，只做信息提示，不警告
                    Debug.Log($"Dimension with ID '{dimension.DimensionId}' already registered with the same instance. Skipping re-registration.");
                    return; // 已经注册且是同一个实例，直接返回
                }
                else
                {
                    // 【逻辑修改】如果是不同实例但ID相同，这是严重错误
                    Debug.LogError(
                        $"CRITICAL ERROR: Dimension with ID '{dimension.DimensionId}' is already registered with a DIFFERENT instance ({existingDimension.name} vs {dimension.name}). This indicates a duplicate DimensionId in the scene. The new instance will overwrite the old one, which may lead to unexpected behavior. Please ensure all Dimension objects have unique IDs.");
                    // 允许覆盖，但以错误日志形式提示，强制开发者修复场景配置。
                }
            }

            _activeDimensions[dimension.DimensionId] = dimension;
            Debug.Log($"Dimension '{dimension.DimensionId}' registered with EntityManage.");

            // 为新注册的维度初始化其数据结构
            // 这些检查是必要的，以防止在重复注册时清空现有数据。
            if (!_dimensionFactionEntities.ContainsKey(dimension.DimensionId))
            {
                _dimensionFactionEntities[dimension.DimensionId] = new Dictionary<string, LinkedList<EntityPrefab>>();
            }

            if (!_dimensionLayerCache.ContainsKey(dimension.DimensionId))
            {
                _dimensionLayerCache[dimension.DimensionId] = new Dictionary<string, Transform>();
            }
        }


        /// <summary>
        /// 从实体管理器注销一个维度。
        /// </summary>
        /// <param name="dimension">要注销的维度实例。</param>
        public void UnregisterDimension(Dimension dimension)
        {
            if (dimension == null || string.IsNullOrEmpty(dimension.DimensionId))
            {
                Debug.LogError("Attempted to unregister a null or invalid Dimension.");
                return;
            }

            if (_activeDimensions.Remove(dimension.DimensionId))
            {
                // 当维度被注销时，清理其所有相关的实体和层级缓存
                _dimensionFactionEntities.Remove(dimension.DimensionId);
                _dimensionLayerCache.Remove(dimension.DimensionId);

                // 【逻辑修改】立即清理_pendingAdditions中属于该维度的实体
                // 创建一个新列表来存储不属于该维度的实体
                var remainingPendingAdditions = new List<Tuple<string, string, EntityPrefab>>();
                foreach (var pending in _pendingAdditions)
                {
                    if (pending.Item1 == dimension.DimensionId)
                    {
                        // 销毁实体GameObject
                        if (pending.Item3 != null && pending.Item3.gameObject != null) // 增加gameObject的null检查
                        {
                            Destroy(pending.Item3.gameObject);
                        }
                    }
                    else
                    {
                        remainingPendingAdditions.Add(pending);
                    }
                }
                _pendingAdditions = remainingPendingAdditions; // 更新_pendingAdditions列表
            }
        }


        /// <summary>
        /// 根据ID获取一个活跃的维度实例。
        /// </summary>
        /// <param name="dimensionId">维度的唯一标识符。</param>
        /// <returns>对应的 Dimension 实例，如果不存在则为 null。</returns>
        public Dimension GetDimension(string dimensionId)
        {
            _activeDimensions.TryGetValue(dimensionId, out var dimension);
            return dimension;
        }

        // --- 查找实体 (现在维度感知) ---
        /// <summary>
        /// 在指定维度中，根据派系键查找所有实体。
        /// </summary>
        /// <param name="dimensionId">维度的唯一标识符。</param>
        /// <param name="factionKey">派系键。</param>
        /// <returns>指定派系下的实体列表，如果未找到则返回空列表。</returns>
        public LinkedList<EntityPrefab> FindEntitiesByFaction(string dimensionId, string factionKey)
        {
            if (_dimensionFactionEntities.TryGetValue(dimensionId, out var factionDict))
            {
                if (factionDict.TryGetValue(factionKey, out var entities))
                {
                    return entities;
                }
            }

            return new LinkedList<EntityPrefab>(); // 如果未找到，返回一个空列表
        }

        // --- Tick 方法 (现在维度感知) ---
        public void Tick()
        {
            // 遍历每个活跃的维度
            foreach (var dimensionEntry in _dimensionFactionEntities.ToList()) // ToList() 避免在迭代时修改字典
            {
                var dimensionId = dimensionEntry.Key;
                var factionDict = dimensionEntry.Value;

                // 检查维度对象本身是否仍然活跃在场景中
                // 注意：这里检查的是 _activeDimensions，确保 Dimension 对象实例仍然存在且被管理器追踪。
                if (!_activeDimensions.ContainsKey(dimensionId))
                {
                    Debug.LogWarning(
                        $"Skipping Tick for dimension '{dimensionId}' as its Dimension object is no longer active. Clearing its entities.");
                    _dimensionFactionEntities.Remove(dimensionId); // 移除已失效维度的实体数据
                    _dimensionLayerCache.Remove(dimensionId); // 移除已失效维度的层级缓存
                    continue;
                }

                foreach (var faction in factionDict)
                {
                    var entitiesToRemove = new List<EntityPrefab>();
                    var currentEntities = faction.Value.ToList(); // 创建副本以避免在迭代时修改列表

                    foreach (var entityPrefab in currentEntities)
                    {
                        // 检查实体预制体或其内部实体是否已销毁或死亡
                        if (entityPrefab == null || entityPrefab.entity == null || entityPrefab.entity.IsDead)
                        {
                            entitiesToRemove.Add(entityPrefab);
                        }
                        else
                        {
                            ITick itike = entityPrefab.entity;
                            itike.Tick();
                        }
                    }

                    // 删除所有标记为死亡的实体
                    foreach (var entityToRemove in entitiesToRemove)
                    {
                        faction.Value.Remove(entityToRemove);
                        if (entityToRemove != null) // 确保它没有被外部销毁
                        {
                            Destroy(entityToRemove.gameObject);
                        }
                    }
                }
            }

            // 处理待添加实体 (现在维度感知)
            if (_pendingAdditions.Any())
            {
                foreach (var pending in _pendingAdditions)
                {
                    var dimensionId = pending.Item1;
                    var factionKey = pending.Item2;
                    var entityPrefab = pending.Item3;

                    // 再次检查维度是否活跃，防止在添加前维度被注销
                    if (!_dimensionFactionEntities.ContainsKey(dimensionId))
                    {
                        Debug.LogError(
                            $"Attempted to add entity '{entityPrefab.name}' to unregistered or inactive dimension '{dimensionId}'. Entity will be destroyed.");
                        if (entityPrefab != null) Destroy(entityPrefab.gameObject);
                        continue;
                    }

                    var factionDict = _dimensionFactionEntities[dimensionId];
                    if (!factionDict.ContainsKey(factionKey))
                    {
                        factionDict[factionKey] = new LinkedList<EntityPrefab>();
                    }

                    factionDict[factionKey].AddLast(entityPrefab);
                }

                _pendingAdditions.Clear();
            }
        }

        /// <summary>
        /// 根据给定的Def生成实体对象（内部通用方法）。
        /// </summary>
        /// <param name="dimensionId">实体所属的维度ID。</param>
        /// <param name="prefab">要实例化的预制体</param>
        /// <param name="pos">生成位置</param>
        /// <param name="def">实体定义对象</param>
        /// <param name="extraInit">额外的初始化操作（如子弹方向设置）</param>
        /// <returns>成功时返回EntityPrefab组件，失败时返回null</returns>
        private EntityPrefab GenerateEntityInternal(
            string dimensionId, // 新增参数：维度ID
            GameObject prefab,
            Vector3 pos,
            Data.EntityDef def,
            Action<EntityPrefab> extraInit = null)
        {
            // 验证维度是否活跃
            if (!_activeDimensions.TryGetValue(dimensionId, out var dimension))
            {
                Debug.LogError($"Cannot generate entity: Dimension '{dimensionId}' is not active or registered.");
                return null;
            }

            // 获取或创建实体所属的层级Transform，并确保其在维度根下
            var parentLayer = EnsureLayerExists(dimensionId, "DefaultEntityLevel"); // 使用一个默认层级名称
            if (parentLayer == null)
            {
                Debug.LogError($"Failed to get or create parent layer for entity in dimension '{dimensionId}'.");
                return null;
            }

            GameObject instantiatedEntity = null;
            try
            {
                // 实例化实体，并将其父级设置为维度下的层级Transform
                instantiatedEntity = Instantiate(prefab, pos, Quaternion.identity, parentLayer);

                var entityComponent = instantiatedEntity.GetComponent<EntityPrefab>();
                if (!entityComponent)
                {
                    throw new InvalidOperationException(
                        $"EntityPrefab component missing on: {instantiatedEntity.name}");
                }

                entityComponent.Init(def);
                extraInit?.Invoke(entityComponent);

                var factionKey = def.attributes.defName ?? "default"; // 假设 attributes.defName 是派系键
                _pendingAdditions.Add(Tuple.Create(dimensionId, factionKey, entityComponent)); // 添加维度ID
                return entityComponent;
            }
            catch (System.Exception ex)
            {
                if (instantiatedEntity) Destroy(instantiatedEntity);
                Debug.LogError($"Entity generation failed in dimension '{dimensionId}': {ex.Message}\n{ex.StackTrace}");
                return null;
            }
        }

        /// <summary>
        /// 动态创建层（如果层不存在），现在是维度感知的。
        /// 每个维度有自己的层级结构，根在 Dimension.DimensionRoot 下。
        /// </summary>
        /// <param name="dimensionId">维度的唯一标识符。</param>
        /// <param name="layerName">要确保存在的层级名称。</param>
        /// <returns>层级Transform，如果维度不存在或其根Transform为空则返回null。</returns>
        private Transform EnsureLayerExists(string dimensionId, string layerName)
        {
            // 尝试从维度层级缓存中获取
            if (!_dimensionLayerCache.TryGetValue(dimensionId, out var layerCacheForDimension))
            {
                Debug.LogError(
                    $"Dimension '{dimensionId}' not found in layer cache. This should not happen if dimension is registered.");
                return null;
            }

            if (layerCacheForDimension.TryGetValue(layerName, out var layerTransform))
            {
                return layerTransform;
            }

            // 如果缓存中没有，尝试在维度根下查找
            var dimension = GetDimension(dimensionId);
            if (dimension == null || dimension.DimensionRoot == null)
            {
                Debug.LogError(
                    $"Dimension '{dimensionId}' or its root transform is null. Cannot create layer '{layerName}'.");
                return null;
            }

            layerTransform = dimension.DimensionRoot.Find(layerName);

            if (!layerTransform)
            {
                // 如果层不存在，动态创建并将其父级设置为维度的根Transform
                var layerObject = new GameObject(layerName);
                layerTransform = layerObject.transform;
                layerTransform.SetParent(dimension.DimensionRoot);
            }

            // 将新创建的层加入缓存
            layerCacheForDimension[layerName] = layerTransform;
            return layerTransform;
        }

        // --- 公共生成方法 (现在维度感知) ---
        /// <summary>
        /// 在指定维度中，根据PawnDef生成普通实体。
        /// </summary>
        public void GenerateEntity(string dimensionId, Data.EntityDef entityDef, Vector3 pos)
        {
            if (!characterPrefab)
            {
                Debug.LogError("characterPrefab is null! Assign a valid prefab.");
                GenerateDefaultEntity(dimensionId, pos);
                return;
            }

            if (entityDef == null)
            {
                Debug.LogError("EntityDef is null! Cannot generate entity.");
                GenerateDefaultEntity(dimensionId, pos);
                return;
            }

            var result = GenerateEntityInternal(
                dimensionId,
                characterPrefab.gameObject,
                pos,
                entityDef
            );
            if (!result) GenerateDefaultEntity(dimensionId, pos);
        }

        /// <summary>
        /// 在指定维度中，生成建筑实体（位置使用Vector3Int）。
        /// </summary>
        public void GenerateBuildingEntity(string dimensionId, Data.BuildingDef buildingDef, Vector3Int pos)
        {
            if (!buildingPrefab)
            {
                Debug.LogError("buildingPrefab is null! Assign a valid prefab.");
                GenerateDefaultEntity(dimensionId, pos);
                return;
            }

            if (buildingDef == null)
            {
                Debug.LogError("BuildingDef is null! Cannot generate building.");
                GenerateDefaultEntity(dimensionId, pos);
                return;
            }

            var worldPos = new Vector3(pos.x, pos.y, pos.z);
            var result = GenerateEntityInternal(
                dimensionId,
                buildingPrefab.gameObject,
                worldPos,
                buildingDef
            );
            if (!result) GenerateDefaultEntity(dimensionId, worldPos);
        }

        /// <summary>
        /// 在指定维度中，生成子弹实体（含方向设置）。
        /// </summary>
        public void GenerateBulletEntity(string dimensionId, Data.BulletDef bulletDef, Vector3 pos, Vector3 dir,
            Entity.Entity source = null)
        {
            if (!bulletPrefab)
            {
                Debug.LogError("bulletPrefab is null! Assign a valid prefab.");
                GenerateDefaultEntity(dimensionId, pos);
                return;
            }

            if (bulletDef == null)
            {
                Debug.LogError("BulletDef is null! Cannot generate bullet.");
                GenerateDefaultEntity(dimensionId, pos);
                return;
            }

            var result = GenerateEntityInternal(
                dimensionId,
                bulletPrefab.gameObject,
                pos,
                bulletDef,
                // 子弹特有的方向设置
                entityComponent => entityComponent.entity.SetTarget(pos + dir)
            );

            // 确保 result 不为 null 且 entity 是 Bullet 类型
            if (result != null && result.entity is Bullet bullet)
            {
                bullet.bulletSource = source;
                if (source != null) bullet.affiliation = source.affiliation; // 确保 source 不为 null
            }

            if (!result) GenerateDefaultEntity(dimensionId, pos);
        }

        /// <summary>
        /// 在指定维度中，生成默认实体（错误回退）。
        /// </summary>
        public void GenerateDefaultEntity(string dimensionId, Vector3 pos)
        {
            if (!_activeDimensions.ContainsKey(dimensionId))
            {
                Debug.LogError(
                    $"Cannot generate default entity: Dimension '{dimensionId}' is not active or registered.");
                return;
            }

            var parentLayer = EnsureLayerExists(dimensionId, "DefaultEntityLevel");
            if (parentLayer == null)
            {
                Debug.LogError($"Failed to get parent transform for default entity in dimension '{dimensionId}'.");
                return;
            }

            var entity = Instantiate(defaultEntityPrefab, pos, Quaternion.identity, parentLayer);
            var entityComponent = entity.GetComponent<EntityPrefab>();

            const string factionKey = "default";
            _pendingAdditions.Add(Tuple.Create(dimensionId, factionKey, entityComponent));
            entityComponent.DefaultInit();
        }

        // --- 单例生命周期与场景切换处理 ---
        protected override void OnStart()
        {
            SceneManager.sceneLoaded += OnSceneLoaded;
        }

        private void OnDestroy()
        {
            SceneManager.sceneLoaded -= OnSceneLoaded;
        }

        /// <summary>
        /// 场景加载完成时的回调。
        /// 清理旧场景的实体数据，并重新扫描新场景中的维度。
        /// </summary>
        private void OnSceneLoaded(Scene scene, LoadSceneMode mode)
        {
            _dimensionFactionEntities.Clear(); // 清理所有维度下的实体数据
            _dimensionLayerCache.Clear(); // 清理所有维度下的层级缓存
            _pendingAdditions.Clear(); // 清理待添加实体列表
            _activeDimensions.Clear(); // 清理活跃维度列表，因为旧场景的维度对象已被销毁
        }
        

        private void Start()
        {
            if (defaultEntityPrefab == null)
            {
                var pre = Resources.Load<GameObject>("Default/DefaultEntity");
                if (pre != null)
                {
                    defaultEntityPrefab = pre.GetComponent<EntityPrefab>();
                }
                else
                {
                    Debug.LogError(
                        "Failed to load DefaultEntity prefab from Resources/Default/DefaultEntity. Please ensure it exists at 'Assets/Resources/Default/DefaultEntity.prefab'.");
                }
            }
        }
    }

}