using System.Collections.Generic;
using Lean.Pool;
using Sirenix.OdinInspector;
using UnityEngine;

namespace SLSUtilities.Effects
{
    public class VFXRaycastInteraction : MonoBehaviour, IPoolable
    {
        [Header("核心设置")]
        [Tooltip("在特效生成时是否立刻启用渐变，注意，必须通过对象池生成。\n为true时，渐变效果从targetLight的默认intensity开始，否则需要调用EnableFade方法启用渐变")]
        public bool playOnSpawn = true;
        public float life = 1f;
        public List<float> checkPoints;
        public int currentCheckPointIndex = 0;
        public bool isEnabling = true;
        public Transform startPoint;     // 刀尖的位置（用于发射射线）
        public LayerMask collisionLayers;  // 地面图层
        public float rayLength = 0.5f; // 射线长度（稍微比刀刃离地距离长一点）

        [Header("特效资源")]
        public GameObject sparkPrefab; // 火星特效 Prefab
        public GameObject decalPrefab; // 划痕 Decal Prefab
        
        [HideInEditorMode]
        [SerializeField]
        private bool isFading;
        [HideInEditorMode]
        [SerializeField]
        private float time;
        private Vector3 _lastTipPosition;
        
        private void Reset()
        {
            startPoint = transform;
            collisionLayers = LayerMask.GetMask("Wall", "Ground");
        }
        
        public void OnSpawn()
        {
            if (playOnSpawn && !isEnabling)
            {
                isEnabling = true;
                time = 0f;
                currentCheckPointIndex = 0;
            }
            
            _lastTipPosition = startPoint.position;
        }
        
        public void OnDespawn()
        {
            isEnabling = false;
        }
        
        void Update()
        {
            time += Time.deltaTime;
            if (time >= life)
            {
                isEnabling = false;
            }
            
            if (!isEnabling || Time.timeScale == 0 || checkPoints.Count == 0) return;
            
            // 1. 计算刀尖速度方向（用于决定划痕朝向）
            Vector3 velocity = (startPoint.position - _lastTipPosition) / Time.deltaTime;
            _lastTipPosition = startPoint.position;

            //1. 检查是否到达下一个检查点
            if (currentCheckPointIndex < checkPoints.Count)
            {
                if (time >= checkPoints[currentCheckPointIndex])
                {
                    currentCheckPointIndex++;
                }
                else
                {
                    return; // 未到达检查点，跳过本次更新
                }
            }
            else
            {
                return; // 所有检查点已处理完，跳过本次更新
            }
            

            // 2. 发射射线检测地面
            // 这里我们向下发射射线。如果你的游戏支持墙壁划痕，可以改为 velocity.normalized
            
            RaycastHit hit;
            if (Physics.Raycast(startPoint.position, startPoint.forward, out hit, rayLength, collisionLayers))
            {
                SpawnEffects(hit, velocity);
            }
        }
        
        void SpawnEffects(RaycastHit hit, Vector3 slashVelocity)
        {
            Vector3 projectedSlashDir = Vector3.ProjectOnPlane(slashVelocity, hit.normal).normalized;
            
            // --- 处理火星 (Spark) ---
            if (sparkPrefab != null)
            {
                // 关键点：使用 Quaternion.LookRotation(hit.normal)
                // 这会让火星特效的 Z轴（发射方向）严格对准地面法线（垂直向上），right方向和挥动方向对齐
                LeanPool.Spawn(sparkPrefab, hit.point, Quaternion.LookRotation(hit.normal, Vector3.Cross(projectedSlashDir, hit.normal)));
            }

            // --- 处理划痕 (Decal) ---
            if (decalPrefab != null)
            {
                // 计算划痕的朝向：
                // 我们希望划痕贴在地面上（法线对齐 hit.normal）
                // 同时划痕的延伸方向要对齐刀的挥动方向（slashVelocity）
                if (projectedSlashDir != Vector3.zero)
                {
                    // 计算 Decal 的旋转，Decal的forward和地面法线对齐，right方向和挥动方向对齐
                    Quaternion decalRotation = Quaternion.LookRotation(hit.normal, Vector3.Cross(projectedSlashDir, hit.normal));
                
                    // 生成 Decal，稍微抬高一点点避免 Z-Fighting
                    GameObject decal = LeanPool.Spawn(decalPrefab, hit.point + hit.normal * 0.01f, decalRotation);
                
                    // 记得在 Prefab 里设置自动销毁，或者在这里写 Destroy
                    LeanPool.Despawn(decal, 5f);
                }
            }
        }
    
        // 用于在 Scene 窗口调试射线，方便你调整 rayLength
        void OnDrawGizmos()
        {
            if (startPoint != null)
            {
                Gizmos.color = Color.yellow;
                Gizmos.DrawLine(startPoint.position, startPoint.position + transform.forward * rayLength);
            }
        }
    }
}