using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.Serialization;
using Pooling;
using AppleHills.Core.Settings;
using Utils;
using AppleHills.Core.Interfaces;

namespace Minigames.DivingForPictures
{
    /// <summary>
    /// Spawns and manages trench wall tiles for the endless descender minigame.
    /// </summary>
    public class TrenchTileSpawner : MonoBehaviour, IPausable
    {
        [Header("Tile Prefabs")]
        [Tooltip("List of possible trench tile prefabs.")]
        [SerializeField] private List<GameObject> tilePrefabs;

        [Header("Initial Tile")]
        [Tooltip("Prefab for the initial trench tile. This will always be spawned first.")]
        [SerializeField] private GameObject initialTilePrefab;

        [Header("Events")]
        [FormerlySerializedAs("OnTileSpawned")] 
        public UnityEvent<GameObject> onTileSpawned;
        
        [FormerlySerializedAs("OnTileDestroyed")] 
        public UnityEvent<GameObject> onTileDestroyed;

        // Settings references
        private IDivingMinigameSettings _settings;
        private DivingDeveloperSettings _devSettings;

        // Private fields
        private readonly Dictionary<GameObject, float> _tileHeights = new Dictionary<GameObject, float>();
        private readonly List<GameObject> _activeTiles = new List<GameObject>();
        private readonly Dictionary<int, int> _tileLastUsed = new Dictionary<int, int>();
        
        private int _spawnCounter;
        private float _speedUpTimer;
        private UnityEngine.Camera _mainCamera;
        private float _screenBottom;
        private float _screenTop;
        private TrenchTilePool _tilePool;
        
        // Current velocity for tile movement
        private float _currentVelocity;

        private const float TileSpawnZ = -1f;
        private const float DefaultTileHeight = 5f;

        // Direction state
        private bool _isSurfacing = false;
        private bool _stopSpawning = false;
        
        // Event triggered when the last tile leaves the screen after stopping spawning
        public UnityEvent onLastTileLeft = new UnityEvent();
        
        // Velocity management
        private float _baseMoveSpeed;
        private float _velocityFactor = 1.0f;
        
        // Coroutine references
        private Coroutine _movementCoroutine;
        private Coroutine _tileDestructionCoroutine;
        private Coroutine _tileSpawningCoroutine;
        private Coroutine _speedRampingCoroutine;
        
        // Screen normalization
        private float _screenNormalizationFactor = 1.0f;

        // Tracks if a floating area in the middle is currently active
        private bool isFloatingAreaActive = false;

        // Current depth of the trench
        private int _currentDepth = 0;

        [System.Serializable]
        public struct DepthDifficultyRange
        {
            public int minDepth;
            public int maxDepth;
            public int difficulty;
        }

        [Header("Difficulty Depths")]
        [Tooltip("Configure depth ranges and their corresponding difficulty levels.")]
        [SerializeField] private List<DepthDifficultyRange> depthDifficultyRanges = new List<DepthDifficultyRange>
        {
            new DepthDifficultyRange { minDepth = 0, maxDepth = 10, difficulty = 1 },
            new DepthDifficultyRange { minDepth = 11, maxDepth = 20, difficulty = 2 },
            new DepthDifficultyRange { minDepth = 21, maxDepth = 30, difficulty = 3 },
            new DepthDifficultyRange { minDepth = 31, maxDepth = 40, difficulty = 4 },
            new DepthDifficultyRange { minDepth = 41, maxDepth = int.MaxValue, difficulty = 5 }
        };

        public int CurrentDifficulty
        {
            get
            {
                foreach (var range in depthDifficultyRanges)
                {
                    if (_currentDepth >= range.minDepth && _currentDepth <= range.maxDepth)
                        return range.difficulty;
                }
                return 1; // Default fallback
            }
        }

        // Pause state
        private bool _isPaused = false;
        
        // IPausable implementation
        public bool IsPaused => _isPaused;

        private void Awake()
        {
            _mainCamera = UnityEngine.Camera.main;
            
            // Get settings from GameManager
            _settings = GameManager.GetSettingsObject<IDivingMinigameSettings>();
            _devSettings = GameManager.GetDeveloperSettings<DivingDeveloperSettings>();
            
            if (_settings == null)
            {
                Debug.LogError("[TrenchTileSpawner] Failed to load diving minigame settings!");
            }
            
            if (_devSettings == null)
            {
                Debug.LogError("[TrenchTileSpawner] Failed to load diving developer settings!");
            }
            
            _baseMoveSpeed = _settings?.NormalizedMoveSpeed ?? 3f; // Store the original base speed
            
            // Calculate tile heights for each prefab
            CalculateTileHeights();
            
            // Ensure all prefabs have Tile components
            ValidateTilePrefabs();
            
            if (_devSettings != null && _devSettings.TrenchTileUseObjectPooling)
            {
                InitializeObjectPool();
            }
        }

        // Validate that all prefabs have Tile components
        private void ValidateTilePrefabs()
        {
            for (int i = 0; i < tilePrefabs.Count; i++)
            {
                if (tilePrefabs[i] == null) continue;
                
                // Check if the prefab has a Tile component
                if (tilePrefabs[i].GetComponent<Tile>() == null)
                {
                    Debug.LogWarning($"Prefab {tilePrefabs[i].name} does not have a Tile component. Adding one automatically.");
                    // Add the Tile component if it doesn't exist
                    tilePrefabs[i].AddComponent<Tile>();
                }
            }
        }

        private void Start()
        {
            DivingGameManager.Instance.OnGameInitialized += Initialize;
            
            // Register with the DivingGameManager for pause/resume events
            DivingGameManager.Instance.RegisterPausableComponent(this);
            
            // If game is already initialized, initialize immediately
            if (DivingGameManager.Instance.GetType().GetField("_isGameInitialized", 
                System.Reflection.BindingFlags.NonPublic | 
                System.Reflection.BindingFlags.Instance)?.GetValue(DivingGameManager.Instance) is bool isInitialized && isInitialized)
            {
                Initialize();
            }
        }
        
        private void OnDestroy()
        {
            DivingGameManager.Instance.UnregisterPausableComponent(this);
        }

        /// <summary>
        /// Pauses the spawner and all associated processes
        /// </summary>
        public void Pause()
        {
            if (_isPaused) return; // Already paused
            
            _isPaused = true;
            
            // Stop all active coroutines but save their references
            if (_movementCoroutine != null)
            {
                StopCoroutine(_movementCoroutine);
                _movementCoroutine = null;
            }
            
            if (_tileDestructionCoroutine != null)
            {
                StopCoroutine(_tileDestructionCoroutine);
                _tileDestructionCoroutine = null;
            }
            
            if (_tileSpawningCoroutine != null)
            {
                StopCoroutine(_tileSpawningCoroutine);
                _tileSpawningCoroutine = null;
            }
            
            if (_speedRampingCoroutine != null)
            {
                StopCoroutine(_speedRampingCoroutine);
                _speedRampingCoroutine = null;
            }
            
            Debug.Log("[TrenchTileSpawner] Paused");
        }
        
        /// <summary>
        /// Resumes the spawner and all associated processes
        /// </summary>
        public void DoResume()
        {
            if (!_isPaused) return; // Already running
            
            _isPaused = false;
            
            // Restart all necessary coroutines
            StartMovementCoroutine();
            StartTileDestructionCoroutine();
            StartTileSpawningCoroutine();
            StartSpeedRampingCoroutine();
            
            Debug.Log("[TrenchTileSpawner] Resumed");
        }
        
        /// <summary>
        /// Initializes the tile spawner when triggered by DivingGameManager
        /// </summary>
        private void Initialize()
        {
            // Calculate screen bounds and normalization factor
            CalculateScreenBounds();
            CalculateScreenNormalizationFactor();
            
            // Spawn initial tiles to fill the screen
            SpawnInitialTiles();
            
            // Initialize velocity and apply screen normalization
            _baseMoveSpeed = _settings?.NormalizedMoveSpeed ?? 3f;
            _currentVelocity = _baseMoveSpeed * Time.fixedDeltaTime * _screenNormalizationFactor;
            
            // Start all coroutines
            StartCoroutine(VelocityCalculationRoutine());
            StartMovementCoroutine();
            StartTileDestructionCoroutine();
            StartTileSpawningCoroutine();
            StartSpeedRampingCoroutine();
            
            Debug.Log("[TrenchTileSpawner] Initialized with normalized speed");
        }
        
        /// <summary>
        /// Gets the current velocity of the tiles
        /// </summary>
        /// <returns>The current upward velocity of the tiles</returns>
        public float GetCurrentVelocity()
        {
            return _currentVelocity;
        }
        
        /// <summary>
        /// Sets a custom velocity, overriding the calculated one
        /// </summary>
        /// <param name="velocity">The new velocity value</param>
        public void SetVelocity(float velocity)
        {
            _currentVelocity = velocity;
        }
        
        /// <summary>
        /// Coroutine that periodically calculates the velocity based on game state
        /// </summary>
        private IEnumerator VelocityCalculationRoutine()
        {
            while (true)
            {
                CalculateVelocity();
                yield return new WaitForSeconds(_settings.VelocityCalculationInterval);
            }
        }
        
        /// <summary>
        /// Calculates the current velocity based on move speed
        /// </summary>
        private void CalculateVelocity()
        {
            _currentVelocity = _baseMoveSpeed * Time.fixedDeltaTime;
        }

        /// <summary>
        /// Calculate height values for all tile prefabs
        /// </summary>
        private void CalculateTileHeights()
        {
            foreach (var prefab in tilePrefabs)
            {
                if (prefab == null)
                {
                    Debug.LogError("Null prefab found in tilePrefabs list!");
                    return;
                }

                Renderer renderer = prefab.GetComponentInChildren<Renderer>();
                if (renderer != null)
                {
                    _tileHeights[prefab] = renderer.bounds.size.y;
                }
                else
                {
                    // Fallback in case no renderer is found
                    _tileHeights[prefab] = DefaultTileHeight;
                    Debug.LogWarning($"No renderer found in prefab {prefab.name}. Using default height of {DefaultTileHeight}.");
                }
            }
        }

        /// <summary>
        /// Initialize the object pool system
        /// </summary>
        private void InitializeObjectPool()
        {
            // Create the tile pool
            GameObject poolGO = new GameObject("TrenchTilePool");
            poolGO.transform.SetParent(transform);
            _tilePool = poolGO.AddComponent<TrenchTilePool>();
            
            // Set up the pool configuration using developer settings
            _tilePool.maxPerPrefabPoolSize = _devSettings.TrenchTileMaxPerPrefabPoolSize;
            _tilePool.totalMaxPoolSize = _devSettings.TrenchTileTotalMaxPoolSize;
            
            // Convert the GameObject list to a Tile list
            List<Tile> prefabTiles = new List<Tile>(tilePrefabs.Count);
            foreach (var prefab in tilePrefabs)
            {
                if (prefab != null)
                {
                    Tile tileComponent = prefab.GetComponent<Tile>();
                    if (tileComponent != null)
                    {
                        prefabTiles.Add(tileComponent);
                    }
                    else
                    {
                        Debug.LogError($"Prefab {prefab.name} is missing a Tile component!");
                    }
                }
            }
            
            // Initialize the pool with the tile component list
            _tilePool.Initialize(prefabTiles);
            
            // Periodically trim the pool to optimize memory usage
            InvokeRepeating(nameof(TrimExcessPooledTiles), 10f, 30f);
        }

        /// <summary>
        /// Spawn the initial set of tiles
        /// </summary>
        private void SpawnInitialTiles()
        {
            // Calculate starting Y position - moved 2 tiles up from the bottom of the screen
            float startingY = _screenBottom;
            
            // If we have prefab tiles with known heights, use their average height for offset calculation
            float tileHeightEstimate = DefaultTileHeight;
            if (tilePrefabs != null && tilePrefabs.Count > 0 && tilePrefabs[0] != null)
            {
                if (_tileHeights.TryGetValue(tilePrefabs[0], out float height))
                {
                    tileHeightEstimate = height;
                }
            }
            
            // Move starting position up by 2 tile heights
            startingY += tileHeightEstimate * 2;
            
            for (int i = 0; i < _settings.InitialTileCount; i++)
            {
                float y = startingY;
                // Calculate proper Y position based on previous tiles
                if (i > 0 && _activeTiles.Count > 0)
                {
                    GameObject prevTile = _activeTiles[_activeTiles.Count - 1];
                    float prevHeight = GetTileHeight(prevTile);
                    y = prevTile.transform.position.y - prevHeight;
                }
                if (i == 0 && initialTilePrefab != null)
                {
                    SpawnSpecificTileAtY(initialTilePrefab, y);
                }
                else
                {
                    SpawnTileAtY(y);
                }
            }
        }

        /// <summary>
        /// Calculate the screen bounds in world space
        /// </summary>
        private void CalculateScreenBounds()
        {
            if (_mainCamera == null)
            {
                _mainCamera = UnityEngine.Camera.main;
                if (_mainCamera == null)
                {
                    Debug.LogError("No main camera found!");
                    return;
                }
            }

            Vector3 bottom = _mainCamera.ViewportToWorldPoint(new Vector3(0.5f, 0f, _mainCamera.nearClipPlane));
            Vector3 top = _mainCamera.ViewportToWorldPoint(new Vector3(0.5f, 1f, _mainCamera.nearClipPlane));
            _screenBottom = bottom.y;
            _screenTop = top.y;
        }

        /// <summary>
        /// Calculates the screen normalization factor based on current screen height
        /// </summary>
        private void CalculateScreenNormalizationFactor()
        {
            // Get reference height from settings with fallback if not available
            float referenceHeight = 1080f; // Default fallback value
            
            if (_settings != null)
            {
                referenceHeight = _settings.ReferenceScreenHeight;
            }
            
            // Calculate normalization factor based on screen height
            _screenNormalizationFactor = Screen.height / referenceHeight;
            Debug.Log($"[TrenchTileSpawner] Screen normalization factor: {_screenNormalizationFactor} (Screen height: {Screen.height}, Reference: {referenceHeight})");
        }
        
        /// <summary>
        /// Called when the velocity factor changes from the DivingGameManager
        /// </summary>
        public void OnVelocityFactorChanged(float velocityFactor)
        {
            _velocityFactor = velocityFactor;
            
            // Update the actual move speed based on the velocity factor
            // This keeps the original move speed intact for game logic
            _baseMoveSpeed = _settings.NormalizedMoveSpeed * Mathf.Abs(_velocityFactor);
            
            // Recalculate velocity immediately
            CalculateVelocity();
            
            Debug.Log($"[TrenchTileSpawner] Velocity factor updated to {_velocityFactor:F2}, moveSpeed: {_baseMoveSpeed:F2}");
        }
        
        /// <summary>
        /// Reverses direction to start surfacing
        /// </summary>
        public void StartSurfacing()
        {
            if (_isSurfacing) return; // Already surfacing
            
            // Set surfacing flag for spawn/despawn logic
            _isSurfacing = true;
            
            // Reverse the active tiles array to maintain consistent indexing logic
            _activeTiles.Reverse();
            
            Debug.Log("[TrenchTileSpawner] Started surfacing - reversed array order");
        }
        
        /// <summary>
        /// Stops spawning new tiles
        /// </summary>
        public void StopSpawning()
        {
            _stopSpawning = true;
        }
        
        /// <summary>
        /// Starts the movement coroutine if it's not already running
        /// </summary>
        private void StartMovementCoroutine()
        {
            if (_movementCoroutine == null && !_isPaused)
            {
                _movementCoroutine = StartCoroutine(MoveActiveTilesRoutine());
            }
        }

        /// <summary>
        /// Coroutine that handles obstacle movement using normalized screen-relative speed
        /// </summary>
        private IEnumerator MoveActiveTilesRoutine()
        {
            Debug.Log($"[TrenchTileSpawner] Started movement coroutine with normalized speed: {_baseMoveSpeed:F3}");
            
            while (enabled && gameObject.activeInHierarchy && !_isPaused)
            {
                // Skip if no active tiles
                if (_activeTiles.Count == 0)
                {
                    yield return null;
                    continue;
                }
                
                // Use velocity factor sign to determine direction
                Vector3 direction = Vector3.up * Mathf.Sign(_velocityFactor);
                
                // Apply normalized movement using the shared utility method
                float speed = AppleHillsUtils.CalculateNormalizedMovementSpeed(_baseMoveSpeed);
                
                // Move all active tiles
                foreach (var tile in _activeTiles)
                {
                    if (tile != null)
                    {
                        // Apply movement in correct direction
                        tile.transform.position += direction * speed;
                    }
                }
                
                // Wait for next frame
                yield return null;
            }
            
            // Clear coroutine reference when stopped
            _movementCoroutine = null;
        }

        /// <summary>
        /// Coroutine that checks for tiles to destroy periodically
        /// </summary>
        private IEnumerator TileDestructionRoutine()
        {
            const float checkInterval = 0.5f; // Check every half second
            Debug.Log($"[TrenchTileSpawner] Started tile destruction coroutine with interval: {checkInterval}s");
            
            while (enabled && gameObject.activeInHierarchy && !_isPaused)
            {
                // Check and handle tile destruction
                if (_activeTiles.Count > 0)
                {
                    GameObject topTile = _activeTiles[0];
                    if (topTile == null)
                    {
                        _activeTiles.RemoveAt(0);
                    }
                    else
                    {
                        float tileHeight = GetTileHeight(topTile);
                        
                        bool shouldDestroy;
                        if (_isSurfacing)
                        {
                            // When surfacing, destroy tiles at the bottom
                            shouldDestroy = topTile.transform.position.y + tileHeight / 2 < _screenBottom - _settings.TileSpawnBuffer;
                        }
                        else
                        {
                            // When descending, destroy tiles at the top
                            shouldDestroy = topTile.transform.position.y - tileHeight / 2 > _screenTop + _settings.TileSpawnBuffer;
                        }
                        
                        if (shouldDestroy)
                        {
                            _activeTiles.RemoveAt(0);
                            onTileDestroyed?.Invoke(topTile);
                            
                            if (_devSettings != null && _devSettings.TrenchTileUseObjectPooling && _tilePool != null)
                            {
                                // Find the prefab index for this tile
                                int prefabIndex = GetPrefabIndex(topTile);
                                if (prefabIndex >= 0)
                                {
                                    _tilePool.ReturnTile(topTile, prefabIndex);
                                }
                                else
                                {
                                    Destroy(topTile);
                                }
                            }
                            else
                            {
                                Destroy(topTile);
                            }
                        }
                    }
                }
                
                // Wait for the next check interval
                yield return new WaitForSeconds(checkInterval);
            }
            
            // Clear coroutine reference when stopped
            _tileDestructionCoroutine = null;
        }
        
        /// <summary>
        /// Coroutine that checks if new tiles need to be spawned periodically
        /// </summary>
        private IEnumerator TileSpawningRoutine()
        {
            const float checkInterval = 0.2f; // Check every fifth of a second
            Debug.Log($"[TrenchTileSpawner] Started tile spawning coroutine with interval: {checkInterval}s");
            
            while (enabled && gameObject.activeInHierarchy && !_isPaused && !_stopSpawning)
            {
                // Check if we need to spawn new tiles
                if (_activeTiles.Count == 0) 
                {
                    // If we have no active tiles and spawning is stopped, trigger the event
                    if (_stopSpawning)
                    {
                        onLastTileLeft.Invoke();
                    }
                }
                else
                {
                    GameObject bottomTile = _activeTiles[^1];
                    if (bottomTile == null)
                    {
                        _activeTiles.RemoveAt(_activeTiles.Count - 1);
                    }
                    else
                    {
                        // Get the tile height once to use in all calculations
                        float tileHeight = GetTileHeight(bottomTile);
                        
                        // If we're in stop spawning mode, check if last tile is leaving
                        if (_stopSpawning)
                        {
                            // Check if this is the last tile, and if it's about to leave the screen
                            if (_activeTiles.Count == 1)
                            {
                                bool isLastTileLeaving;
                                
                                if (_isSurfacing)
                                {
                                    // When surfacing, check if bottom of tile is above top of screen
                                    isLastTileLeaving = bottomTile.transform.position.y - tileHeight / 2 > _screenTop + _settings.TileSpawnBuffer;
                                }
                                else
                                {
                                    // When descending, check if top of tile is below bottom of screen
                                    isLastTileLeaving = bottomTile.transform.position.y + tileHeight / 2 < _screenBottom - _settings.TileSpawnBuffer;
                                }
                                
                                if (isLastTileLeaving)
                                {
                                    onLastTileLeft.Invoke();
                                }
                            }
                        }
                        else
                        {
                            // Normal spawning mode
                            bool shouldSpawn;
                            float newY;
                            
                            if (_isSurfacing)
                            {
                                // When surfacing, spawn new tiles at the top
                                float topEdge = bottomTile.transform.position.y + tileHeight / 2;
                                shouldSpawn = topEdge < _screenTop + _settings.TileSpawnBuffer;
                                newY = bottomTile.transform.position.y + tileHeight;
                            }
                            else
                            {
                                // When descending, spawn new tiles at the bottom
                                float bottomEdge = bottomTile.transform.position.y - tileHeight / 2;
                                shouldSpawn = bottomEdge > _screenBottom - _settings.TileSpawnBuffer;
                                newY = bottomTile.transform.position.y - tileHeight;
                            }
                            
                            if (shouldSpawn)
                            {
                                SpawnTileAtY(newY);
                            }
                        }
                    }
                }
                
                // Wait for the next check interval
                yield return new WaitForSeconds(checkInterval);
            }
            
            // Clear coroutine reference when stopped
            _tileSpawningCoroutine = null;
        }

        /// <summary>
        /// Coroutine that handles increasing the movement speed over time
        /// </summary>
        private IEnumerator SpeedRampingRoutine()
        {
            const float checkInterval = 1.0f; // Check once per second
            Debug.Log($"[TrenchTileSpawner] Started speed ramping coroutine with interval: {checkInterval}s");
            
            while (enabled && gameObject.activeInHierarchy && !_isPaused)
            {
                // Increase the base move speed up to the maximum
                _baseMoveSpeed = Mathf.Min(_baseMoveSpeed + _settings.SpeedUpFactor, _settings.MaxNormalizedMoveSpeed);
                
                // Recalculate velocity with the new base speed
                CalculateVelocity();
                
                // Wait for the next check interval
                yield return new WaitForSeconds(checkInterval);
            }
            
            // Clear coroutine reference when stopped
            _speedRampingCoroutine = null;
        }

        /// <summary>
        /// Checks if two tiles are fully compatible for spawning, following clarified floating area rules.
        /// </summary>
        private bool AreTilesFullyCompatible(Tile prev, Tile next)
        {
            // Path compatibility: at least one path is open in both Out (prev) and In (next)
            bool pathCompatible =
                (prev.pathOutLeft && next.pathInLeft) ||
                (prev.pathOutCenter && next.pathInCenter) ||
                (prev.pathOutRight && next.pathInRight);

            // --- Updated floating area rules ---
            // Continue tile: can only spawn after Start, and must be followed by End
            if (next.continuesFloatingAreaMiddle)
            {
                if (!prev.hasFloatingAreaMiddle)
                    return false;
            }
            // End tile: can only spawn after Start or Continue
            if (next.endsFloatingAreaMiddle)
            {
                if (!(prev.hasFloatingAreaMiddle || prev.continuesFloatingAreaMiddle))
                    return false;
            }
            // After a Start tile, only Continue or End can follow
            if (prev.hasFloatingAreaMiddle)
            {
                if (!(next.continuesFloatingAreaMiddle || next.endsFloatingAreaMiddle))
                    return false;
            }
            // After a Continue tile, only End can follow
            if (prev.continuesFloatingAreaMiddle)
            {
                if (!next.endsFloatingAreaMiddle)
                    return false;
            }
            // Otherwise, normal tiles are always allowed
            return pathCompatible;
        }

        /// <summary>
        /// Gets a weighted random index among fully compatible tiles, prioritizing least recently used.
        /// </summary>
        private int GetWeightedCompatibleTileIndex(Tile prevTile)
        {
            var compatibleIndices = new List<int>();
            int currentDifficulty = CurrentDifficulty;
            for (int i = 0; i < tilePrefabs.Count; i++)
            {
                var candidateGO = tilePrefabs[i];
                var candidate = candidateGO?.GetComponent<Tile>();
                if (candidate == null) continue;
                if (candidate.difficultyLevel > currentDifficulty) continue;
                bool compatible = AreTilesFullyCompatible(prevTile, candidate);
                if (compatible)
                    compatibleIndices.Add(i);
            }
            if (compatibleIndices.Count == 0)
            {
                Debug.LogError("No compatible tile found for previous tile and current difficulty. Spawning aborted.");
                return -1;
            }
            List<float> weights = new List<float>(compatibleIndices.Count);
            foreach (var i in compatibleIndices)
            {
                int lastUsed = _tileLastUsed.TryGetValue(i, out var value) ? value : -tilePrefabs.Count;
                int age = _spawnCounter - lastUsed;
                float weight = Mathf.Clamp(age, 1, tilePrefabs.Count * 2);
                weights.Add(weight);
            }
            float totalWeight = 0f;
            foreach (var weight in weights)
                totalWeight += weight;
            float randomValue = Random.value * totalWeight;
            for (int idx = 0; idx < compatibleIndices.Count; idx++)
            {
                if (randomValue < weights[idx])
                    return compatibleIndices[idx];
                randomValue -= weights[idx];
            }
            return compatibleIndices[Random.Range(0, compatibleIndices.Count)];
        }

        /// <summary>
        /// Spawn a new tile at the specified Y position
        /// </summary>
        /// <param name="y">The Y position to spawn at</param>
        private void SpawnTileAtY(float y)
        {
            if (tilePrefabs == null || tilePrefabs.Count == 0)
            {
                Debug.LogError("No tile prefabs available for spawning!");
                return;
            }

            int prefabIndex;
            // First tile: any tile
            if (_activeTiles.Count == 0)
            {
                prefabIndex = GetWeightedRandomTileIndex();
            }
            else
            {
                GameObject prevTileGO = _activeTiles[_activeTiles.Count - 1];
                Tile prevTile = prevTileGO != null ? prevTileGO.GetComponent<Tile>() : null;
                if (prevTile != null)
                {
                    // Use weighted compatible selection
                    prefabIndex = GetWeightedCompatibleTileIndex(prevTile);
                    if (prefabIndex == -1)
                    {
                        Debug.LogError("No compatible tile can be spawned after previous tile. Aborting spawn.");
                        return;
                    }
                }
                else
                {
                    prefabIndex = GetWeightedRandomTileIndex();
                }
            }

            GameObject prefab = tilePrefabs[prefabIndex];
            if (prefab == null)
            {
                Debug.LogError($"Tile prefab at index {prefabIndex} is null!");
                return;
            }

            GameObject tile;
            if (_devSettings != null && _devSettings.TrenchTileUseObjectPooling && _tilePool != null)
            {
                tile = _tilePool.GetTile(prefabIndex);
                if (tile == null)
                {
                    Debug.LogError("Failed to get tile from pool!");
                    return;
                }
                tile.transform.position = new Vector3(0f, y, TileSpawnZ);
                tile.transform.rotation = prefab.transform.rotation;
                tile.transform.SetParent(transform);
                if (_devSettings != null)
                {
                    tile.layer = _devSettings.TrenchTileLayer;
                    SetLayerRecursively(tile, _devSettings.TrenchTileLayer);
                }
            }
            else
            {
                tile = Instantiate(prefab, new Vector3(0f, y, TileSpawnZ), prefab.transform.rotation, transform);
                if (_devSettings != null)
                {
                    tile.layer = _devSettings.TrenchTileLayer;
                    SetLayerRecursively(tile, _devSettings.TrenchTileLayer);
                }
            }
            _activeTiles.Add(tile);
            _tileLastUsed[prefabIndex] = _spawnCounter++;
            _currentDepth++;
            Debug.Log($"[TrenchTileSpawner] Current Depth: {_currentDepth}");
            onTileSpawned?.Invoke(tile);

            // --- FLOATING AREA STATE MANAGEMENT ---
            Tile spawnedTile = tile.GetComponent<Tile>();
            if (spawnedTile != null)
            {
                if (spawnedTile.hasFloatingAreaMiddle || spawnedTile.continuesFloatingAreaMiddle)
                {
                    isFloatingAreaActive = true;
                }
                if (spawnedTile.endsFloatingAreaMiddle)
                {
                    isFloatingAreaActive = false;
                }
            }
        }

        /// <summary>
        /// Spawn a specific tile at the specified Y position
        /// </summary>
        /// <param name="prefab">The tile prefab to spawn</param>
        /// <param name="y">The Y position to spawn at</param>
        private void SpawnSpecificTileAtY(GameObject prefab, float y)
        {
            GameObject tile;
            if (_devSettings != null && _devSettings.TrenchTileUseObjectPooling && _tilePool != null)
            {
                int prefabIndex = tilePrefabs.IndexOf(prefab);
                if (prefabIndex >= 0)
                {
                    tile = _tilePool.GetTile(prefabIndex);
                    if (tile == null)
                    {
                        Debug.LogError("Failed to get initial tile from pool!");
                        return;
                    }
                }
                else
                {
                    tile = Instantiate(prefab, new Vector3(0f, y, TileSpawnZ), prefab.transform.rotation, transform);
                }
                tile.transform.position = new Vector3(0f, y, TileSpawnZ);
                tile.transform.rotation = prefab.transform.rotation;
                tile.transform.SetParent(transform);
                if (_devSettings != null)
                {
                    tile.layer = _devSettings.TrenchTileLayer;
                    SetLayerRecursively(tile, _devSettings.TrenchTileLayer);
                }
            }
            else
            {
                tile = Instantiate(prefab, new Vector3(0f, y, TileSpawnZ), prefab.transform.rotation, transform);
                if (_devSettings != null)
                {
                    tile.layer = _devSettings.TrenchTileLayer;
                    SetLayerRecursively(tile, _devSettings.TrenchTileLayer);
                }
            }
            _activeTiles.Add(tile);
            _currentDepth++;
            Debug.Log($"[TrenchTileSpawner] Current Depth: {_currentDepth}");
            onTileSpawned?.Invoke(tile);
            // Optionally update floating area state if needed
            Tile spawnedTile = tile.GetComponent<Tile>();
            if (spawnedTile != null)
            {
                if (spawnedTile.hasFloatingAreaMiddle || spawnedTile.continuesFloatingAreaMiddle)
                {
                    isFloatingAreaActive = true;
                }
                if (spawnedTile.endsFloatingAreaMiddle)
                {
                    isFloatingAreaActive = false;
                }
            }
        }

        /// <summary>
        /// Gets a list of allowed tile indices for the current difficulty
        /// </summary>
        /// <returns>List of allowed prefab indices</returns>
        private List<int> GetAllowedTileIndicesForCurrentDifficulty()
        {
            var allowedIndices = new List<int>();
            int currentDifficulty = CurrentDifficulty;
            for (int i = 0; i < tilePrefabs.Count; i++)
            {
                var tileComponent = tilePrefabs[i]?.GetComponent<Tile>();
                if (tileComponent != null && tileComponent.difficultyLevel <= currentDifficulty)
                {
                    allowedIndices.Add(i);
                }
            }
            return allowedIndices;
        }

        /// <summary>
        /// Gets a weighted random tile index, favoring tiles that haven't been used recently
        /// </summary>
        /// <returns>The selected prefab index</returns>
        private int GetWeightedRandomTileIndex()
        {
            var allowedIndices = GetAllowedTileIndicesForCurrentDifficulty();
            if (allowedIndices.Count == 0)
            {
                Debug.LogError("No allowed tiles for current difficulty!");
                return 0;
            }
            List<float> weights = new List<float>(allowedIndices.Count);

            for (int i = 0; i < allowedIndices.Count; i++)
            {
                int lastUsed = _tileLastUsed.TryGetValue(allowedIndices[i], out var value) ? value : -tilePrefabs.Count;
                int age = _spawnCounter - lastUsed;
                float weight = Mathf.Clamp(age, 1, tilePrefabs.Count * 2); // More unused = higher weight
                weights.Add(weight);
            }

            float totalWeight = 0f;
            foreach (var weight in weights)
            {
                totalWeight += weight;
            }

            float randomValue = Random.value * totalWeight;
            for (int i = 0; i < allowedIndices.Count; i++)
            {
                if (randomValue < weights[i])
                {
                    return allowedIndices[i];
                }
                randomValue -= weights[i];
            }

            return Random.Range(0, allowedIndices.Count); // fallback
        }

        /// <summary>
        /// Gets the height of a tile based on its prefab or renderer bounds
        /// </summary>
        /// <param name="tile">The tile to measure</param>
        /// <returns>The height of the tile</returns>
        private float GetTileHeight(GameObject tile)
        {
            if (tile == null)
            {
                Debug.LogWarning("Attempted to get height of null tile!");
                return DefaultTileHeight;
            }

            // Check if this is a known prefab
            foreach (var prefab in tilePrefabs)
            {
                if (prefab == null) continue;

                // Check if this tile was created from this prefab
                if (tile.name.StartsWith(prefab.name))
                {
                    if (_tileHeights.TryGetValue(prefab, out float height))
                    {
                        return height;
                    }
                }
            }

            // If not found, calculate it from the renderer
            Renderer renderer = tile.GetComponentInChildren<Renderer>();
            if (renderer != null)
            {
                return renderer.bounds.size.y;
            }

            // Fallback
            return DefaultTileHeight;
        }

        /// <summary>
        /// Gets the index of the prefab that was used to create this tile
        /// </summary>
        /// <param name="tile">The tile to check</param>
        /// <returns>The index of the prefab or -1 if not found</returns>
        private int GetPrefabIndex(GameObject tile)
        {
            if (tile == null || tilePrefabs == null)
            {
                return -1;
            }

            for (int i = 0; i < tilePrefabs.Count; i++)
            {
                if (tilePrefabs[i] == null) continue;

                if (tile.name.StartsWith(tilePrefabs[i].name))
                {
                    return i;
                }
            }
            return -1;
        }

        /// <summary>
        /// Called periodically to trim excess pooled tiles
        /// </summary>
        private void TrimExcessPooledTiles()
        {
            if (_tilePool != null)
            {
                _tilePool.TrimExcess();
            }
        }

#if UNITY_EDITOR
        private void OnDrawGizmosSelected()
        {
            if (!Application.isPlaying)
            {
                // Only try to calculate this if _screenBottom hasn't been set by the game
                UnityEngine.Camera editorCam = UnityEngine.Camera.main;
                if (editorCam != null)
                {
                    Vector3 bottom = editorCam.ViewportToWorldPoint(new Vector3(0.5f, 0f, editorCam.nearClipPlane));
                    _screenBottom = bottom.y;
                }
            }

            // Draw tile bounds for debugging
            Gizmos.color = Color.cyan;
            if (_settings != null)
            {
                for (int i = 0; i < _settings.InitialTileCount; i++)
                {
                    float height = DefaultTileHeight;
                    if (tilePrefabs != null && tilePrefabs.Count > 0 && tilePrefabs[0] != null && 
                        _tileHeights.TryGetValue(tilePrefabs[0], out float h))
                    {
                        height = h;
                    }
                    Vector3 center = new Vector3(0f, _screenBottom + i * height, 0f);
                    Gizmos.DrawWireCube(center, new Vector3(10f, height, 1f));
                }
            }
        }
#endif

        /// <summary>
        /// Set the layer of a GameObject and all its children recursively
        /// </summary>
        /// <param name="obj">The GameObject to set the layer for</param>
        /// <param name="layer">The layer index to set</param>
        private void SetLayerRecursively(GameObject obj, int layer)
        {
            if (obj == null) return;

            obj.layer = layer;

            foreach (Transform child in obj.transform)
            {
                if (child != null)
                {
                    SetLayerRecursively(child.gameObject, layer);
                }
            }
        }

        /// <summary>
        /// Starts the tile destruction coroutine and stores its reference
        /// </summary>
        private void StartTileDestructionCoroutine()
        {
            if (_tileDestructionCoroutine != null)
            {
                StopCoroutine(_tileDestructionCoroutine);
            }
            _tileDestructionCoroutine = StartCoroutine(TileDestructionCoroutine());
        }
        
        /// <summary>
        /// Coroutine that checks for tiles to destroy periodically
        /// </summary>
        private IEnumerator TileDestructionCoroutine()
        {
            const float checkInterval = 0.5f; // Check every half second as requested
            Debug.Log($"[TrenchTileSpawner] Started tile destruction coroutine with interval: {checkInterval}s");
            
            while (enabled && gameObject.activeInHierarchy)
            {
                // Check and handle tile destruction
                if (_activeTiles.Count > 0)
                {
                    GameObject topTile = _activeTiles[0];
                    if (topTile == null)
                    {
                        _activeTiles.RemoveAt(0);
                    }
                    else
                    {
                        float tileHeight = GetTileHeight(topTile);
                        
                        bool shouldDestroy;
                        if (_isSurfacing)
                        {
                            // When surfacing, destroy tiles at the bottom
                            shouldDestroy = topTile.transform.position.y + tileHeight / 2 < _screenBottom - _settings.TileSpawnBuffer;
                        }
                        else
                        {
                            // When descending, destroy tiles at the top
                            shouldDestroy = topTile.transform.position.y - tileHeight / 2 > _screenTop + _settings.TileSpawnBuffer;
                        }
                        
                        if (shouldDestroy)
                        {
                            _activeTiles.RemoveAt(0);
                            onTileDestroyed?.Invoke(topTile);
                            
                            if (_devSettings != null && _devSettings.TrenchTileUseObjectPooling && _tilePool != null)
                            {
                                // Find the prefab index for this tile
                                int prefabIndex = GetPrefabIndex(topTile);
                                if (prefabIndex >= 0)
                                {
                                    _tilePool.ReturnTile(topTile, prefabIndex);
                                }
                                else
                                {
                                    Destroy(topTile);
                                }
                            }
                            else
                            {
                                Destroy(topTile);
                            }
                        }
                    }
                }
                
                // Wait for the next check interval
                yield return new WaitForSeconds(checkInterval);
            }
        }

        /// <summary>
        /// Starts the tile spawning coroutine and stores its reference
        /// </summary>
        private void StartTileSpawningCoroutine()
        {
            if (_tileSpawningCoroutine != null)
            {
                StopCoroutine(_tileSpawningCoroutine);
            }
            _tileSpawningCoroutine = StartCoroutine(TileSpawningCoroutine());
        }
        
        /// <summary>
        /// Coroutine that checks if new tiles need to be spawned periodically
        /// </summary>
        private IEnumerator TileSpawningCoroutine()
        {
            const float checkInterval = 0.2f; // Check every half second as requested
            Debug.Log($"[TrenchTileSpawner] Started tile spawning coroutine with interval: {checkInterval}s");
            
            while (enabled && gameObject.activeInHierarchy)
            {
                // Check if we need to spawn new tiles
                if (_activeTiles.Count == 0) 
                {
                    // If we have no active tiles and spawning is stopped, trigger the event
                    if (_stopSpawning)
                    {
                        onLastTileLeft.Invoke();
                    }
                }
                else
                {
                    GameObject bottomTile = _activeTiles[^1];
                    if (bottomTile == null)
                    {
                        _activeTiles.RemoveAt(_activeTiles.Count - 1);
                    }
                    else
                    {
                        // Get the tile height once to use in all calculations
                        float tileHeight = GetTileHeight(bottomTile);
                        
                        // If we're in stop spawning mode, check if last tile is leaving
                        if (_stopSpawning)
                        {
                            // Check if this is the last tile, and if it's about to leave the screen
                            if (_activeTiles.Count == 1)
                            {
                                bool isLastTileLeaving;
                                
                                if (_isSurfacing)
                                {
                                    // When surfacing, check if bottom of tile is above top of screen
                                    isLastTileLeaving = bottomTile.transform.position.y - tileHeight / 2 > _screenTop + _settings.TileSpawnBuffer;
                                }
                                else
                                {
                                    // When descending, check if top of tile is below bottom of screen
                                    isLastTileLeaving = bottomTile.transform.position.y + tileHeight / 2 < _screenBottom - _settings.TileSpawnBuffer;
                                }
                                
                                if (isLastTileLeaving)
                                {
                                    onLastTileLeft.Invoke();
                                }
                            }
                        }
                        else
                        {
                            // Normal spawning mode
                            bool shouldSpawn;
                            float newY;
                            
                            if (_isSurfacing)
                            {
                                // When surfacing, spawn new tiles at the top
                                float topEdge = bottomTile.transform.position.y + tileHeight / 2;
                                shouldSpawn = topEdge < _screenTop + _settings.TileSpawnBuffer;
                                newY = bottomTile.transform.position.y + tileHeight;
                            }
                            else
                            {
                                // When descending, spawn new tiles at the bottom
                                float bottomEdge = bottomTile.transform.position.y - tileHeight / 2;
                                shouldSpawn = bottomEdge > _screenBottom - _settings.TileSpawnBuffer;
                                newY = bottomTile.transform.position.y - tileHeight;
                            }
                            
                            if (shouldSpawn)
                            {
                                SpawnTileAtY(newY);
                            }
                        }
                    }
                }
                
                // Wait for the next check interval
                yield return new WaitForSeconds(checkInterval);
            }
        }

        /// <summary>
        /// Starts the speed ramping coroutine and stores its reference
        /// </summary>
        private void StartSpeedRampingCoroutine()
        {
            if (_speedRampingCoroutine != null)
            {
                StopCoroutine(_speedRampingCoroutine);
            }
            _speedRampingCoroutine = StartCoroutine(SpeedRampingRoutine());
        }
    }
}