using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// 鱼对象池 - 复用鱼对象避免频繁 Instantiate/Destroy
/// </summary>
public class FishObjectPool : MonoBehaviour
{
    public static FishObjectPool Instance { get; private set; }
    
    [System.Serializable]
    public class PoolConfig
    {
        public FishType fishType;
        public int initialSize = 5;  // 初始池大小
        public int maxSize = 20;     // 最大池大小
    }
    
    [Header("对象池配置")]
    public List<PoolConfig> poolConfigs = new List<PoolConfig>();
    
    // 对象池字典：FishType -> 对象队列
    private Dictionary<FishType, Queue<GameObject>> fishPools = new Dictionary<FishType, Queue<GameObject>>();
    private Dictionary<FishType, PoolConfig> configMap = new Dictionary<FishType, PoolConfig>();
    
    // 记录从池中取出的对象，用于回收时识别类型
    private Dictionary<GameObject, FishType> activeFishMap = new Dictionary<GameObject, FishType>();
    
    void Awake()
    {
        Instance = this;
    }
    
    /// <summary>
    /// 初始化对象池 - 在游戏开始前调用
    /// </summary>
    public void InitializePools()
    {
        // 构建配置映射
        foreach (var config in poolConfigs)
        {
            configMap[config.fishType] = config;
        }
        
        // 为每种配置的鱼创建初始池
        foreach (var config in poolConfigs)
        {
            CreatePool(config.fishType, config.initialSize);
        }
        
        Debug.Log($"[FishObjectPool] 对象池初始化完成，共 {poolConfigs.Count} 种鱼类型");
    }
    
    /// <summary>
    /// 创建指定类型的对象池
    /// </summary>
    void CreatePool(FishType fishType, int size)
    {
        fishPools[fishType] = new Queue<GameObject>();
        
        int fishId = (int)fishType;
        GameObject prefab = GameManager.Ins.GetFishPre(fishId - 1);
        
        if (prefab == null)
        {
            Debug.LogError($"[FishObjectPool] 找不到鱼预制体: {fishType}");
            return;
        }
        
        // 预创建对象
        for (int i = 0; i < size; i++)
        {
            GameObject fish = Instantiate(prefab, transform);
            
            // 禁用 SplineController，防止在隐藏状态下运行并报错
            var splineController = fish.GetComponent<FluffyUnderware.Curvy.Controllers.SplineController>();
            if (splineController != null)
            {
                splineController.enabled = false;
            }
            
            fish.SetActive(false);
            fishPools[fishType].Enqueue(fish);
        }
    }
    
    /// <summary>
    /// 从对象池获取鱼
    /// </summary>
    public GameObject GetFish(FishType fishType)
    {
        // 确保池存在
        if (!fishPools.ContainsKey(fishType))
        {
            // 如果没有配置，使用默认配置创建
            var config = new PoolConfig { fishType = fishType, initialSize = 3, maxSize = 10 };
            configMap[fishType] = config;
            CreatePool(fishType, config.initialSize);
        }
        
        var pool = fishPools[fishType];
        GameObject fish = null;
        
        // 从池中取出一个可用的对象
        while (pool.Count > 0)
        {
            fish = pool.Dequeue();
            if (fish != null) // 防止对象已被销毁
            {
                break;
            }
        }
        
        // 池为空则创建新对象
        if (fish == null)
        {
            int fishId = (int)fishType;
            GameObject prefab = GameManager.Ins.GetFishPre(fishId - 1);
            if (prefab != null)
            {
                fish = Instantiate(prefab);
                Debug.Log($"[FishObjectPool] 池为空，创建新对象: {fishType}");
            }
        }
        
        if (fish != null)
        {
            // 在激活前确保 SplineController 被禁用
            // 防止在 Init 设置 Spline 之前 Update 运行
            var splineController = fish.GetComponent<FluffyUnderware.Curvy.Controllers.SplineController>();
            if (splineController != null)
            {
                splineController.enabled = false;
            }
            
            fish.SetActive(true);
            activeFishMap[fish] = fishType;
        }
        
        return fish;
    }
    
    /// <summary>
    /// 回收鱼到对象池
    /// </summary>
    public void ReturnFish(GameObject fish)
    {
        if (fish == null) return;
        
        // 获取鱼的类型
        if (!activeFishMap.TryGetValue(fish, out FishType fishType))
        {
            // 如果找不到类型映射，尝试从 Fish 组件获取
            var fishComponent = fish.GetComponent<Fish>();
            if (fishComponent != null && fishComponent.Data != null)
            {
                fishType = (FishType)fishComponent.Data.FishId;
            }
            else
            {
                // 无法识别类型，直接销毁
                Destroy(fish);
                return;
            }
        }
        
        // 从活跃映射中移除
        activeFishMap.Remove(fish);
        
        // 确保池存在
        if (!fishPools.ContainsKey(fishType))
        {
            fishPools[fishType] = new Queue<GameObject>();
        }
        
        var pool = fishPools[fishType];
        var config = configMap.ContainsKey(fishType) ? configMap[fishType] : null;
        
        // 如果池未满，回收对象
        if (config == null || pool.Count < config.maxSize)
        {
            // 重置对象状态
            fish.SetActive(false);
            fish.transform.SetParent(transform);
            fish.transform.localPosition = Vector3.zero;
            
            // 重置 Fish 组件状态
            var fishComponent = fish.GetComponent<Fish>();
            if (fishComponent != null)
            {
                fishComponent.ResetForPool();
            }
            
            pool.Enqueue(fish);
        }
        else
        {
            // 池已满，销毁对象
            Destroy(fish);
        }
    }
    
    /// <summary>
    /// 清空所有对象池
    /// </summary>
    public void ClearAllPools()
    {
        foreach (var pool in fishPools.Values)
        {
            while (pool.Count > 0)
            {
                var fish = pool.Dequeue();
                if (fish != null)
                {
                    Destroy(fish);
                }
            }
        }
        fishPools.Clear();
        activeFishMap.Clear();
    }
    
    /// <summary>
    /// 获取池状态信息（调试用）
    /// </summary>
    public string GetPoolStatus()
    {
        System.Text.StringBuilder sb = new System.Text.StringBuilder();
        sb.AppendLine("[FishObjectPool] 对象池状态:");
        foreach (var pair in fishPools)
        {
            sb.AppendLine($"  {pair.Key}: {pair.Value.Count} 个可用");
        }
        return sb.ToString();
    }
}