using UnityEngine;
using UnityEngine.AI;
using System.Collections.Generic;
using BITKit;

namespace Net.Project.B.AI
{

    public class SpawnManager : MonoBehaviour
    {
        public float spawnRadius = 20f; // 刷怪区域半径
        public int maxSpawnPoints = 10; // 最大刷怪点数量
        public float minDistanceBetweenSpawns = 5f; // 最小刷怪点间距
        public float clearanceCheckDistance = 3f; // 空旷度检测半径
        public GameObject enemyPrefab; // 怪物预制体

        void Start()
        {
            List<Vector3> spawnPoints = GenerateSpawnPoints(transform.position, spawnRadius, minDistanceBetweenSpawns,
                maxSpawnPoints);
            foreach (var point in spawnPoints)
            {
                Instantiate(enemyPrefab, point, Quaternion.identity);
                Debug.DrawRay(point, Vector3.up * 2, Color.green, 5f); // 可视化调试
            }
        }

        List<Vector3> GenerateSpawnPoints(Vector3 center, float radius, float minDist, int maxPoints)
        {
            List<Vector3> spawnPoints = new List<Vector3>();
            int attempts = 0;

            while (spawnPoints.Count < maxPoints && attempts < maxPoints * 10)
            {
                Vector3 randomPoint = center + Random.insideUnitSphere * radius;
                randomPoint.y = center.y; // 保持 Y 轴位置

                if (NavMesh.SamplePosition(randomPoint, out NavMeshHit hit, 2f, NavMesh.AllAreas))
                {
                    if (IsClearArea(hit.position, minDist, spawnPoints) && IsSpacious(hit.position))
                    {
                        spawnPoints.Add(hit.position);
                    }
                }

                attempts++;
            }

            return spawnPoints;
        }

        // 确保刷怪点不会过近
        bool IsClearArea(Vector3 pos, float minDist, List<Vector3> points)
        {
            foreach (var p in points)
            {
                if (Vector3.Distance(p, pos) < minDist)
                    return false;
            }

            return true;
        }

        // 确保周围没有障碍物，区域足够空旷
        bool IsSpacious(Vector3 pos)
        {
            for (int i = 0; i < 8; i++)
            {
                Vector3 dir = Quaternion.Euler(0, i * 45, 0) * Vector3.forward * clearanceCheckDistance;
                if (NavMesh.Raycast(pos, pos + dir, out _, NavMesh.AllAreas))
                {
                    return false; // 遇到障碍，位置不合适
                }
            }

            return true;
        }
#if UNITY_EDITOR

        [BIT]
        private void Sample()
        {
            _spawnPoints =
                GenerateSpawnPoints(transform.position, spawnRadius, minDistanceBetweenSpawns, maxSpawnPoints);
        }

        private List<Vector3> _spawnPoints = new();

        // 可视化调试刷怪点
        void OnDrawGizmos()
        {
            if (Application.isPlaying) return;
            Gizmos.color = Color.red;

            foreach (var point in _spawnPoints)
            {
                Gizmos.DrawSphere(point, 0.5f);
            }
        }
#endif     
    }
               
}