using UnityEngine;
using System.Collections.Generic;

namespace GameSystems.Optimization
{
    [DisallowMultipleComponent]
    [AddComponentMenu("Game Systems/Optimization/Player Range Manager")]
    public sealed class PlayerRangeManager : MonoBehaviour
    {
        #region Serialized Fields

        [Header("=== 필수 설정 ===")]
        [SerializeField, Tooltip("최적화 설정 에셋")]
        private RenderOptimizationConfig _config;

        [SerializeField, Tooltip("환경 오브젝트들이 들어있는 부모 폴더 리스트")]
        private List<Transform> _environmentParents = new List<Transform>(); // ⭐ 리스트 방식으로 변경

        #endregion

        #region Private Fields

        private Transform _playerTransform;
        private readonly List<RenderGroup> _renderGroups = new List<RenderGroup>(512);

        private bool _isInitialized;
        private bool _isPaused;

        private int _totalObjectCount;
        private int _visibleObjectCount;
        private int _lastFrameChangedCount;
        private float _nextCheckTime;

        #endregion

        #region Public Properties

        public bool IsInitialized => _isInitialized;
        public bool IsPaused => _isPaused;
        public int TotalObjectCount => _totalObjectCount;
        public int VisibleObjectCount => _visibleObjectCount;
        public float CullingEfficiency => _totalObjectCount > 0 ? 1f - ((float)_visibleObjectCount / _totalObjectCount) : 0f;

        #endregion

        private void Awake() { ValidateConfiguration(); }
        private void Start() { InitializeSystem(); }

        private void Update()
        {
            if (!_isInitialized || _isPaused) return;
            if (Time.time >= _nextCheckTime)
            {
                UpdateCulling();
                _nextCheckTime = Time.time + GetCheckInterval();
            }
        }

        private void ValidateConfiguration()
        {
            if (_config == null) _config = RenderOptimizationConfig.CreateDefault();
        }

        public void InitializeSystem()
        {
            if (!FindPlayer()) return;
            if (!ScanEnvironmentObjects()) return;

            _isInitialized = true;
            _nextCheckTime = Time.time;
        }

        private bool FindPlayer()
        {
            GameObject playerObj = GameObject.FindGameObjectWithTag(GetPlayerTag());
            _playerTransform = (playerObj != null) ? playerObj.transform : transform;
            return true;
        }

        // ⭐ [핵심 수정] 리스트 내의 모든 폴더를 뒤져서 '낱개' 단위로 등록합니다.
        private bool ScanEnvironmentObjects()
        {
            if (_environmentParents == null || _environmentParents.Count == 0) return false;

            _renderGroups.Clear();

            foreach (Transform parent in _environmentParents)
            {
                if (parent == null) continue;

                // ⭐ 폴더 구조가 몇 층이든 상관없이 모든 Renderer를 낱낱이 찾아냅니다.
                Renderer[] allRenderers = parent.GetComponentsInChildren<Renderer>(_config.IncludeInactiveObjects);

                foreach (Renderer r in allRenderers)
                {
                    if (r == null) continue;
                    // 각 렌더러를 독립적인 그룹으로 생성 (개별 최적화의 핵심)
                    _renderGroups.Add(new RenderGroup(new Renderer[] { r }));
                }
            }

            _totalObjectCount = _renderGroups.Count;
            return _totalObjectCount > 0;
        }

        private void UpdateCulling()
        {
            if (_playerTransform == null) return;

            Vector3 playerPosition = _playerTransform.position;
            float maxDistance = GetRenderRange();
            int changedCount = 0;
            int visibleCount = 0;

            for (int i = 0; i < _renderGroups.Count; i++)
            {
                if (_renderGroups[i].UpdateVisibility(playerPosition, maxDistance)) changedCount++;
                if (_renderGroups[i].IsVisible) visibleCount++;
            }

            _visibleObjectCount = visibleCount;
            _lastFrameChangedCount = changedCount;
        }

        public void RefreshObjectList() { ScanEnvironmentObjects(); }
        public void ShowAllObjects() { foreach (var g in _renderGroups) g.ForceShow(); _visibleObjectCount = _totalObjectCount; }
        public void HideAllObjects() { foreach (var g in _renderGroups) g.ForceHide(); _visibleObjectCount = 0; }
        public void SetPaused(bool paused) => _isPaused = paused;

        private float GetRenderRange() => _config.RenderRange;
        private float GetCheckInterval() => _config.CheckInterval;
        private string GetPlayerTag() => _config.PlayerTag;
        private bool ShouldShowGizmos() => _config.ShowGizmos;

        private void OnDrawGizmos()
        {
            if (!ShouldShowGizmos() || _playerTransform == null) return;
            Gizmos.color = new Color(1f, 0f, 0f, 0.3f);
            Gizmos.DrawWireSphere(_playerTransform.position, GetRenderRange());
        }

        private void OnDrawGizmosSelected()
        {
            if (!ShouldShowGizmos() || !_isInitialized) return;
            foreach (var group in _renderGroups)
            {
                Gizmos.color = group.IsVisible ? new Color(0f, 1f, 0f, 0.5f) : new Color(0.5f, 0.5f, 0.5f, 0.2f);
                Gizmos.DrawSphere(group.ActualCenter, 0.3f);
            }
        }
    }
}