using UnityEngine;
using System.Collections;
using Pooling;

namespace Minigames.DivingForPictures
{
    /// <summary>
    /// Complete floating obstacle component that handles movement and pooling.
    /// Obstacles move upward toward the surface. Collision detection is handled by the player.
    /// Once an obstacle hits the player, its collider is disabled to prevent further collisions.
    /// Uses coroutines for better performance instead of Update() calls.
    /// </summary>
    public class FloatingObstacle : MonoBehaviour, IPoolable
    {
        [Header("Obstacle Properties")]
        [Tooltip("Index of the prefab this obstacle was created from")]
        [SerializeField] private int prefabIndex;
        
        [Tooltip("Movement speed of this obstacle")]
        [SerializeField] private float moveSpeed = 2f;
        
        [Header("Movement")]
        [Tooltip("Whether this obstacle moves (can be disabled for static obstacles)")]
        [SerializeField] private bool enableMovement = true;
        
        [Header("References")]
        [Tooltip("Reference to the spawner that created this obstacle")]
        [SerializeField] private ObstacleSpawner spawner;
        
        // Public properties
        public int PrefabIndex
        {
            get => prefabIndex;
            set => prefabIndex = value;
        }
        
        public float MoveSpeed
        {
            get => moveSpeed;
            set => moveSpeed = value;
        }
        
        // Private fields
        private Collider2D _collider;
        private Camera _mainCamera;
        private float _screenTop;
        private float _screenBottom; // Added to track bottom of screen
        private Coroutine _movementCoroutine;
        private Coroutine _offScreenCheckCoroutine;
        private bool _isSurfacing = false; // Flag to track surfacing state
        private float _velocityFactor = 1.0f; // Current velocity factor from game manager
        private float _baseMoveSpeed; // Original move speed before velocity factor is applied
        
        private void Awake()
        {
            _collider = GetComponent<Collider2D>();
            
            if (_collider == null)
            {
                _collider = GetComponentInChildren<Collider2D>();
            }
            
            if (_collider == null)
            {
                Debug.LogError($"[FloatingObstacle] No Collider2D found on {gameObject.name}!");
            }
            
            _mainCamera = Camera.main;
            _baseMoveSpeed = moveSpeed; // Store original speed
        }
        
        private void OnEnable()
        {
            StartObstacleBehavior();
        }
        
        private void OnDisable()
        {
            StopObstacleBehavior();
        }
        
        /// <summary>
        /// Starts the obstacle behavior coroutines
        /// </summary>
        private void StartObstacleBehavior()
        {
            if (enableMovement)
            {
                _movementCoroutine = StartCoroutine(MovementCoroutine());
            }
            
            _offScreenCheckCoroutine = StartCoroutine(OffScreenCheckCoroutine());
        }
        
        /// <summary>
        /// Stops all obstacle behavior coroutines
        /// </summary>
        private void StopObstacleBehavior()
        {
            if (_movementCoroutine != null)
            {
                StopCoroutine(_movementCoroutine);
                _movementCoroutine = null;
            }
            
            if (_offScreenCheckCoroutine != null)
            {
                StopCoroutine(_offScreenCheckCoroutine);
                _offScreenCheckCoroutine = null;
            }
        }
        
        /// <summary>
        /// Called when the velocity factor changes from the DivingGameManager via ObstacleSpawner
        /// </summary>
        public void OnVelocityFactorChanged(float velocityFactor)
        {
            _velocityFactor = velocityFactor;
            
            // Update actual move speed based on velocity factor and base speed
            // We use Abs for magnitude and Sign for direction
            moveSpeed = _baseMoveSpeed * Mathf.Abs(_velocityFactor);
            
            // Restart movement with new speed if needed
            if (enableMovement && gameObject.activeInHierarchy)
            {
                if (_movementCoroutine != null)
                {
                    StopCoroutine(_movementCoroutine);
                }
                _movementCoroutine = StartCoroutine(MovementCoroutine());
            }
            
            Debug.Log($"[FloatingObstacle] {gameObject.name} velocity factor updated to {_velocityFactor:F2}, speed: {moveSpeed:F2}");
        }
        
        /// <summary>
        /// Coroutine that handles obstacle movement
        /// </summary>
        private IEnumerator MovementCoroutine()
        {
            while (enabled && gameObject.activeInHierarchy)
            {
                // Use velocity factor sign to determine direction
                Vector3 direction = Vector3.up * Mathf.Sign(_velocityFactor);
                float speed = moveSpeed * Time.deltaTime;
                
                // Apply movement in correct direction
                transform.position += direction * speed;
                
                // Wait for next frame
                yield return null;
            }
        }
        
        /// <summary>
        /// Coroutine that checks if obstacle has moved off-screen
        /// Runs at a lower frequency than movement for better performance
        /// </summary>
        private IEnumerator OffScreenCheckCoroutine()
        {
            const float checkInterval = 0.2f; // Check every 200ms instead of every frame
            
            while (enabled && gameObject.activeInHierarchy)
            {
                CheckIfOffScreen();
                
                // Wait for the check interval
                yield return new WaitForSeconds(checkInterval);
            }
        }
        
        /// <summary>
        /// Disables the collider after hitting the player to prevent further collisions
        /// This is more performant than tracking hit state
        /// </summary>
        public void MarkDamageDealt()
        {
            if (_collider != null && _collider.enabled)
            {
                _collider.enabled = false;
                Debug.Log($"[FloatingObstacle] Obstacle {gameObject.name} hit player - collider disabled");
            }
        }
        
        /// <summary>
        /// Checks if the obstacle has moved off-screen and should be despawned
        /// </summary>
        private void CheckIfOffScreen()
        {
            if (_mainCamera == null) 
            {
                _mainCamera = Camera.main;
                if (_mainCamera == null) return;
            }
            
            // Always recalculate screen bounds to ensure accuracy
            Vector3 topWorldPoint = _mainCamera.ViewportToWorldPoint(new Vector3(0.5f, 1f, _mainCamera.transform.position.z));
            _screenTop = topWorldPoint.y;
            
            Vector3 bottomWorldPoint = _mainCamera.ViewportToWorldPoint(new Vector3(0.5f, 0f, _mainCamera.transform.position.z));
            _screenBottom = bottomWorldPoint.y;
            
            // Check if obstacle is significantly above screen top (obstacles move upward)
            // Use a larger buffer to ensure obstacles are truly off-screen before returning to pool
            if (transform.position.y > _screenTop + 5f)
            {
                Debug.Log($"[FloatingObstacle] {gameObject.name} off-screen at Y:{transform.position.y:F2}, screen top:{_screenTop:F2}");
                ReturnToPool();
            }
            else if (transform.position.y < _screenBottom - 5f) // Added check for bottom screen edge
            {
                Debug.Log($"[FloatingObstacle] {gameObject.name} below screen at Y:{transform.position.y:F2}, screen bottom:{_screenBottom:F2}");
                ReturnToPool();
            }
        }
        
        /// <summary>
        /// Returns this obstacle to the spawner's pool
        /// </summary>
        private void ReturnToPool()
        {
            // CRITICAL: Stop all behavior first to prevent race conditions
            // This ensures no more off-screen checks or movement happen during pool return
            StopObstacleBehavior();
            
            if (spawner != null)
            {
                spawner.ReturnObstacleToPool(gameObject, prefabIndex);
            }
            else
            {
                // Try to find the spawner instead of destroying the object
                ObstacleSpawner foundSpawner = FindFirstObjectByType<ObstacleSpawner>();
                if (foundSpawner != null)
                {
                    Debug.LogWarning($"[FloatingObstacle] Obstacle {gameObject.name} lost spawner reference, found replacement spawner");
                    spawner = foundSpawner;
                    spawner.ReturnObstacleToPool(gameObject, prefabIndex);
                }
                else
                {
                    // No spawner found - just deactivate the object instead of destroying it
                    Debug.LogWarning($"[FloatingObstacle] No spawner found for {gameObject.name}, deactivating safely");
                    gameObject.SetActive(false);
                    
                    // Move to a safe location to avoid interference
                    transform.position = new Vector3(1000f, 1000f, 0f);
                }
            }
        }
        
        /// <summary>
        /// Sets the spawner reference for this obstacle
        /// </summary>
        /// <param name="obstacleSpawner">The spawner that created this obstacle</param>
        public void SetSpawner(ObstacleSpawner obstacleSpawner)
        {
            spawner = obstacleSpawner;
        }
        
        /// <summary>
        /// Called when the obstacle is retrieved from the pool
        /// </summary>
        public void OnSpawn()
        {
            // Reset all state first
            _screenTop = 0f; // Reset cached screen bounds
            _mainCamera = Camera.main; // Refresh camera reference
            
            // Re-enable the collider for reuse
            if (_collider != null)
            {
                _collider.enabled = true;
            }
            
            Debug.Log($"[FloatingObstacle] Obstacle {gameObject.name} spawned from pool");
            
            // Note: Don't start coroutines here - OnEnable() will handle that when SetActive(true) is called
        }
        
        /// <summary>
        /// Called when the obstacle is returned to the pool
        /// </summary>
        public void OnDespawn()
        {
            // Stop all coroutines before returning to pool
            StopObstacleBehavior();
            
            // Re-enable collider for next use (in case it was disabled)
            if (_collider != null)
            {
                _collider.enabled = true;
            }
            
            Debug.Log($"[FloatingObstacle] Obstacle {gameObject.name} despawned to pool");
        }
        
        /// <summary>
        /// Public method to manually trigger return to pool (for external systems)
        /// </summary>
        public void ForceReturnToPool()
        {
            ReturnToPool();
        }
        
        /// <summary>
        /// Public method to enable/disable movement at runtime
        /// </summary>
        public void SetMovementEnabled(bool enabled)
        {
            if (enableMovement == enabled) return;
            
            enableMovement = enabled;
            
            // Restart coroutines to apply movement change
            if (gameObject.activeInHierarchy)
            {
                StopObstacleBehavior();
                StartObstacleBehavior();
            }
        }
        
        /// <summary>
        /// Sets surfacing mode, which reverses obstacle movement direction
        /// </summary>
        public void StartSurfacing()
        {
            if (_isSurfacing) return; // Already surfacing
            
            _isSurfacing = true;
            
            // Reverse movement speed (already handled by ObstacleSpawner, but this ensures consistency)
            moveSpeed *= -1;
            
            Debug.Log($"[FloatingObstacle] {gameObject.name} started surfacing with speed: {moveSpeed}");
        }
    }
}