using UnityEngine;
using System.Collections.Generic;
#if UNITY_EDITOR
using UnityEditor;
#endif

namespace Northbound
{
    public class ObstacleSpawner : MonoBehaviour
    {
        [System.Serializable]
        public class ObstacleEntry
        {
            [Tooltip("배치할 장애물 프리팹")]
            public GameObject prefab;
            
            [Tooltip("이 장애물의 스폰 가중치 (높을수록 자주 등장)")]
            [Range(1, 100)]
            public int spawnWeight = 50;
            
            [Tooltip("최소 스폰 개수")]
            public int minCount = 0;
            
            [Tooltip("최대 스폰 개수")]
            public int maxCount = 10;
        }

        [Header("Spawn Area Settings")]
        [Tooltip("장애물을 배치할 영역의 중심점 (비어있으면 현재 위치 사용)")]
        [SerializeField] private Transform spawnCenter;
        
        [Tooltip("배치 영역의 크기")]
        [SerializeField] private Vector2 spawnAreaSize = new Vector2(50f, 50f);
        
        [Tooltip("배치 영역의 형태")]
        [SerializeField] private SpawnAreaShape areaShape = SpawnAreaShape.Rectangle;

        [Header("Obstacle Settings")]
        [Tooltip("배치할 장애물 목록")]
        [SerializeField] private List<ObstacleEntry> obstacles = new List<ObstacleEntry>();
        
        [Tooltip("장애물 밀도 (0.0 ~ 1.0, 높을수록 많이 배치)")]
        [Range(0f, 1f)]
        [SerializeField] private float density = 0.5f;
        
        [Tooltip("최대 장애물 개수")]
        [SerializeField] private int maxTotalObstacles = 100;

        [Header("Placement Rules")]
        [Tooltip("장애물 간 최소 거리")]
        [SerializeField] private float minDistanceBetweenObstacles = 2f;
        
        [Tooltip("지형에 맞춰 배치")]
        [SerializeField] private bool alignToTerrain = true;
        
        [Tooltip("Y축 랜덤 회전 적용")]
        [SerializeField] private bool randomRotation = true;
        
        [Tooltip("크기 랜덤 변화 범위 (0이면 변화 없음)")]
        [Range(0f, 0.5f)]
        [SerializeField] private float scaleVariation = 0.1f;
        
        [Tooltip("배치 시도 최대 횟수")]
        [SerializeField] private int maxAttempts = 50;

        [Header("Collision Check")]
        [Tooltip("배치 전 충돌 체크")]
        [SerializeField] private bool checkCollision = true;
        
        [Tooltip("충돌 체크 레이어")]
        [SerializeField] private LayerMask collisionLayers = -1;
        
        [Tooltip("충돌 체크 반경")]
        [SerializeField] private float collisionCheckRadius = 1f;

        [Header("Runtime Settings")]
        [Tooltip("게임 시작 시 자동 생성")]
        [SerializeField] private bool spawnOnStart = true;
        
        [Tooltip("생성된 장애물을 부모로 그룹화")]
        [SerializeField] private bool groupUnderParent = true;

        private List<Vector3> _spawnedPositions = new List<Vector3>();
        private Transform _obstacleParent;

        public enum SpawnAreaShape
        {
            Rectangle,
            Circle
        }

        private void Start()
        {
            if (spawnOnStart)
            {
                SpawnObstacles();
            }
        }

        /// <summary>
        /// 장애물을 생성합니다
        /// </summary>
        public void SpawnObstacles()
        {
            ClearObstacles();
            _spawnedPositions.Clear();

            if (obstacles.Count == 0)
            {
                Debug.LogWarning("[ObstacleSpawner] 배치할 장애물이 없습니다!");
                return;
            }

            if (groupUnderParent)
            {
                _obstacleParent = new GameObject("Generated Obstacles").transform;
                _obstacleParent.SetParent(transform);
            }

            Vector3 center = transform.position;
            int totalSpawned = 0;
            int targetCount = Mathf.RoundToInt(maxTotalObstacles * density);

            Debug.Log($"<color=cyan>[ObstacleSpawner] 장애물 생성 시작 (목표: {targetCount}개)</color>");

            // 각 장애물 타입별로 최소 개수 보장
            foreach (var obstacle in obstacles)
            {
                if (obstacle.prefab == null) continue;

                int minRequired = obstacle.minCount;
                for (int i = 0; i < minRequired && totalSpawned < maxTotalObstacles; i++)
                {
                    if (TrySpawnObstacle(obstacle, center))
                    {
                        totalSpawned++;
                    }
                }
            }

            // 나머지를 가중치에 따라 랜덤 배치
            int consecutiveFailures = 0;
            int maxConsecutiveFailures = 50; // 연속 실패 허용 횟수

            while (totalSpawned < targetCount && consecutiveFailures < maxConsecutiveFailures)
            {
                ObstacleEntry selectedObstacle = SelectRandomObstacle();
                if (selectedObstacle == null || selectedObstacle.prefab == null)
                {
                    consecutiveFailures++;
                    continue;
                }

                // 최대 개수 체크
                int currentCount = CountObstacleType(selectedObstacle.prefab);
                if (currentCount >= selectedObstacle.maxCount)
                {
                    consecutiveFailures++;
                    
                    // 모든 장애물이 최대치에 도달했는지 확인
                    if (AllObstaclesAtMax())
                    {
                        Debug.Log("<color=yellow>[ObstacleSpawner] 모든 장애물이 최대 개수에 도달했습니다.</color>");
                        break;
                    }
                    continue;
                }

                if (TrySpawnObstacle(selectedObstacle, center))
                {
                    totalSpawned++;
                    consecutiveFailures = 0; // 성공 시 카운터 리셋
                }
                else
                {
                    consecutiveFailures++;
                }
            }

            if (consecutiveFailures >= maxConsecutiveFailures)
            {
                Debug.LogWarning($"<color=yellow>[ObstacleSpawner] 배치 공간이 부족합니다. {totalSpawned}개만 생성되었습니다.</color>");
            }

            Debug.Log($"<color=green>[ObstacleSpawner] 장애물 생성 완료: {totalSpawned}개</color>");
        }

        private bool AllObstaclesAtMax()
        {
            foreach (var obstacle in obstacles)
            {
                if (obstacle.prefab == null) continue;

                int currentCount = CountObstacleType(obstacle.prefab);
                if (currentCount < obstacle.maxCount)
                {
                    return false;
                }
            }
            return true;
        }

        private bool TrySpawnObstacle(ObstacleEntry obstacleEntry, Vector3 center)
        {
            for (int attempt = 0; attempt < maxAttempts; attempt++)
            {
                Vector3 randomPos = GetRandomPositionInArea(center);

                // 최소 거리 체크
                if (!IsValidPosition(randomPos))
                {
                    Debug.Log($"<color=orange>[Spawn] 최소 거리 체크 실패: {randomPos}</color>");
                    continue;
                }

                // 충돌 체크
                if (checkCollision && Physics.CheckSphere(randomPos, collisionCheckRadius, collisionLayers))
                {
                    Debug.Log($"<color=orange>[Spawn] 충돌 감지: {randomPos}, 반경: {collisionCheckRadius}</color>");
                    continue;
                }

                // 지형에 맞춤
                if (alignToTerrain)
                {
                    if (Physics.Raycast(randomPos + Vector3.up * 100f, Vector3.down, out RaycastHit hit, 200f))
                    {
                        randomPos = hit.point;
                        Debug.Log($"<color=cyan>[Spawn] 지형 감지 성공: {hit.collider.name}</color>");
                    }
                    else
                    {
                        Debug.Log($"<color=orange>[Spawn] 지형 감지 실패: {randomPos}</color>");
                        // 지형이 없어도 배치 시도
                    }
                }

                // 장애물 생성
                Quaternion rotation = randomRotation 
                    ? Quaternion.Euler(0, Random.Range(0f, 360f), 0) 
                    : Quaternion.identity;

                GameObject obstacle = Instantiate(obstacleEntry.prefab, randomPos, rotation);

                if (groupUnderParent && _obstacleParent != null)
                {
                    obstacle.transform.SetParent(_obstacleParent);
                }

                // 크기 변화
                if (scaleVariation > 0)
                {
                    float scale = 1f + Random.Range(-scaleVariation, scaleVariation);
                    obstacle.transform.localScale *= scale;
                }

                _spawnedPositions.Add(randomPos);
                Debug.Log($"<color=green>[Spawn] 장애물 배치 성공: {obstacleEntry.prefab.name} at {randomPos}</color>");
                return true;
            }

            Debug.LogWarning($"<color=red>[Spawn] {obstacleEntry.prefab.name} 배치 실패 (시도: {maxAttempts}회)</color>");
            return false;
        }

        private Vector3 GetRandomPositionInArea(Vector3 center)
        {
            Vector3 randomPos = center;

            switch (areaShape)
            {
                case SpawnAreaShape.Rectangle:
                    randomPos.x += Random.Range(-spawnAreaSize.x / 2, spawnAreaSize.x / 2);
                    randomPos.z += Random.Range(-spawnAreaSize.y / 2, spawnAreaSize.y / 2);
                    break;

                case SpawnAreaShape.Circle:
                    Vector2 randomCircle = Random.insideUnitCircle * spawnAreaSize.x / 2;
                    randomPos.x += randomCircle.x;
                    randomPos.z += randomCircle.y;
                    break;
            }

            return randomPos;
        }

        private bool IsValidPosition(Vector3 position)
        {
            foreach (var spawnedPos in _spawnedPositions)
            {
                if (Vector3.Distance(position, spawnedPos) < minDistanceBetweenObstacles)
                {
                    return false;
                }
            }
            return true;
        }

        private ObstacleEntry SelectRandomObstacle()
        {
            if (obstacles.Count == 0) return null;

            int totalWeight = 0;
            foreach (var obstacle in obstacles)
            {
                if (obstacle.prefab != null)
                {
                    totalWeight += obstacle.spawnWeight;
                }
            }

            if (totalWeight == 0) return null;

            int randomValue = Random.Range(0, totalWeight);
            int currentWeight = 0;

            foreach (var obstacle in obstacles)
            {
                if (obstacle.prefab == null) continue;

                currentWeight += obstacle.spawnWeight;
                if (randomValue < currentWeight)
                {
                    return obstacle;
                }
            }

            return obstacles[0];
        }

        private int CountObstacleType(GameObject prefab)
        {
            int count = 0;
            if (_obstacleParent != null)
            {
                foreach (Transform child in _obstacleParent)
                {
                    if (child.name.StartsWith(prefab.name))
                    {
                        count++;
                    }
                }
            }
            return count;
        }

        /// <summary>
        /// 생성된 장애물을 모두 제거합니다
        /// </summary>
        public void ClearObstacles()
        {
            if (_obstacleParent != null)
            {
                if (Application.isPlaying)
                {
                    Destroy(_obstacleParent.gameObject);
                }
                else
                {
                    DestroyImmediate(_obstacleParent.gameObject);
                }
                _obstacleParent = null;
            }

            _spawnedPositions.Clear();
        }

        private void OnDrawGizmos()
        {
            Vector3 center = transform.position;

            Gizmos.color = new Color(0, 1, 0, 0.3f);

            switch (areaShape)
            {
                case SpawnAreaShape.Rectangle:
                    Gizmos.DrawCube(center, new Vector3(spawnAreaSize.x, 0.1f, spawnAreaSize.y));
                    break;

                case SpawnAreaShape.Circle:
                    DrawCircle(center, spawnAreaSize.x / 2, 32);
                    break;
            }

            Gizmos.color = Color.green;
            Gizmos.DrawWireCube(center, new Vector3(spawnAreaSize.x, 0.1f, spawnAreaSize.y));
        }

        private void DrawCircle(Vector3 center, float radius, int segments)
        {
            float angleStep = 360f / segments;
            Vector3 prevPoint = center + new Vector3(radius, 0, 0);

            for (int i = 1; i <= segments; i++)
            {
                float angle = i * angleStep * Mathf.Deg2Rad;
                Vector3 newPoint = center + new Vector3(Mathf.Cos(angle) * radius, 0, Mathf.Sin(angle) * radius);
                Gizmos.DrawLine(prevPoint, newPoint);
                prevPoint = newPoint;
            }
        }

        private void OnDrawGizmosSelected()
        {
            #if UNITY_EDITOR
            Vector3 center = spawnCenter != null ? spawnCenter.position : transform.position;
            
            // 밀도 정보 표시
            int targetCount = Mathf.RoundToInt(maxTotalObstacles * density);
            Handles.Label(center + Vector3.up * 2f, 
                $"Obstacle Spawner\n목표: {targetCount}개 / 최대: {maxTotalObstacles}개\n밀도: {density:P0}");

            // 생성된 장애물 위치 표시
            Gizmos.color = Color.yellow;
            foreach (var pos in _spawnedPositions)
            {
                Gizmos.DrawWireSphere(pos, minDistanceBetweenObstacles / 2f);
            }
            #endif
        }
    }
}