using Core;
using Minigames.TrashMaze.Core;
using UnityEngine;
using System.Collections;
using AppleHills.Core.Settings;

namespace Minigames.TrashMaze.Objects
{
    /// <summary>
    /// Reveal mode for object visibility
    /// </summary>
    public enum RevealMode
    {
        Binary,        // Simple on/off reveal (current system)
        Progressive    // Pixel-by-pixel progressive reveal with stamp texture
    }
    
    /// <summary>
    /// Component for objects that need reveal memory (obstacles, booster packs, treasures).
    /// Tracks if object has been revealed and updates material properties accordingly.
    /// </summary>
    [RequireComponent(typeof(SpriteRenderer))]
    public class RevealableObject : MonoBehaviour
    {
        [Header("Reveal Settings")]
        [SerializeField] private RevealMode revealMode = RevealMode.Binary;
        
        [Header("Textures")]
        [SerializeField] private Sprite normalSprite;
        [SerializeField] private Sprite outlineSprite;
        
        [Header("Progressive Reveal Settings")]
        [SerializeField, Range(0.5f, 3f)] private float stampWorldRadius = 1.5f;
        [Tooltip("Size of each stamp in world units. Smaller = more gradual reveal. Should be smaller than vision radius.")]
        
        [Header("Object Type")]
        [SerializeField] private bool isBoosterPack = false;
        [SerializeField] private bool isExit = false;
        
        private SpriteRenderer _spriteRenderer;
        private Material _instanceMaterial;
        private bool _hasBeenRevealed = false;
        private bool _isCollected = false;
        
        // Material property IDs (cached for performance)
        private static readonly int IsRevealedID = Shader.PropertyToID("_IsRevealed");
        private static readonly int IsInVisionID = Shader.PropertyToID("_IsInVision");
        private static readonly int RevealMaskID = Shader.PropertyToID("_RevealMask");
        
        // Progressive reveal system
        private RenderTexture _revealStampTexture;
        private Coroutine _stampCoroutine;
        private Bounds _objectBounds;
        private float _activationDistance;
        
        // Binary reveal system
        private Coroutine _binaryRevealCoroutine;
        
        private void Awake()
        {
            _spriteRenderer = GetComponent<SpriteRenderer>();
            
            if (_spriteRenderer.material == null)
            {
                Logging.Error($"[RevealableObject] No material assigned to {gameObject.name}");
                return;
            }
            
            // Create instance material
            _instanceMaterial = new Material(_spriteRenderer.material);
            _spriteRenderer.material = _instanceMaterial;
            
            // Call mode-specific initialization - COMPLETELY SEPARATE
            if (revealMode == RevealMode.Binary)
            {
                InitializeBinaryMode();
            }
            else if (revealMode == RevealMode.Progressive)
            {
                InitializeProgressiveMode();
            }
        }
        
        // ========================================
        // BINARY MODE INITIALIZATION
        // ========================================
        
        private void InitializeBinaryMode()
        {
            // Validate Binary shader
            string shaderName = _instanceMaterial.shader.name;
            if (!shaderName.Contains("ObjectVisibility") || shaderName.Contains("Progressive"))
            {
                Logging.Error($"[RevealableObject] {gameObject.name} Binary mode needs shader 'TrashMaze/ObjectVisibility', currently: {shaderName}");
            }
            
            // Set initial Binary mode properties
            _instanceMaterial.SetFloat(IsRevealedID, 0f);
            _instanceMaterial.SetFloat(IsInVisionID, 0f);
            
            // Set textures
            if (normalSprite != null)
            {
                _instanceMaterial.SetTexture("_MainTex", normalSprite.texture);
            }
            if (outlineSprite != null)
            {
                _instanceMaterial.SetTexture("_OutlineTex", outlineSprite.texture);
            }
            
            Logging.Debug($"[RevealableObject] {gameObject.name} Binary mode initialized");
        }
        
        // ========================================
        // PROGRESSIVE MODE INITIALIZATION
        // ========================================
        
        private void InitializeProgressiveMode()
        {
            // Validate Progressive shader
            string shaderName = _instanceMaterial.shader.name;
            if (!shaderName.Contains("ObjectVisibilityProgressive"))
            {
                Logging.Error($"[RevealableObject] {gameObject.name} Progressive mode needs shader 'TrashMaze/ObjectVisibilityProgressive', currently: {shaderName}");
            }
            
            // Initialize progressive reveal system
            InitializeProgressiveReveal();
        }
        
        /// <summary>
        /// Initialize progressive reveal system with dynamic texture sizing
        /// </summary>
        private void InitializeProgressiveReveal()
        {
            // Get object bounds for UV calculations
            _objectBounds = _spriteRenderer.bounds;
            
            // Load activation distance from settings (use vision radius from follower settings)
            var configs = GameManager.GetSettingsObject<IPlayerMovementConfigs>();
            _activationDistance = configs.FollowerMovement.TrashMazeVisionRadius;
            
            Logging.Debug($"[RevealableObject] {gameObject.name} loaded activation distance from settings: {_activationDistance}");
            
            // Dynamically determine texture size from sprite
            int textureWidth = 128;
            int textureHeight = 128;
            
            if (normalSprite != null && normalSprite.texture != null)
            {
                // Use sprite's texture resolution (match 1:1 for pixel-perfect)
                textureWidth = normalSprite.texture.width;
                textureHeight = normalSprite.texture.height;
            }
            else
            {
                Logging.Warning($"[RevealableObject] {gameObject.name} in Progressive mode but normalSprite not assigned! Using default 128x128 texture. Assign Normal Sprite in inspector!");
            }
            
            // Create reveal stamp texture (R8 format = 8-bit grayscale, minimal memory)
            _revealStampTexture = new RenderTexture(textureWidth, textureHeight, 0, RenderTextureFormat.R8);
            _revealStampTexture.filterMode = FilterMode.Point; // Sharp edges for binary reveals
            _revealStampTexture.wrapMode = TextureWrapMode.Clamp;
            _revealStampTexture.Create(); // Explicitly create the texture
            
            // Clear to black (nothing revealed initially)
            RenderTexture previousActive = RenderTexture.active;
            RenderTexture.active = _revealStampTexture;
            GL.Clear(false, true, Color.black);
            RenderTexture.active = previousActive;
            
            Logging.Debug($"[RevealableObject] {gameObject.name} cleared reveal texture to black - should be invisible initially");
            
            // Set Progressive shader properties
            _instanceMaterial.SetTexture(RevealMaskID, _revealStampTexture);
            
            // Progressive shader uses global _PlayerWorldPos and _VisionRadius (set by PulverController)
            // No need to set _IsInVision - shader does per-pixel distance checks
            
            // Set textures
            if (normalSprite != null)
            {
                _instanceMaterial.SetTexture("_MainTex", normalSprite.texture);
            }
            if (outlineSprite != null)
            {
                _instanceMaterial.SetTexture("_OutlineTex", outlineSprite.texture);
            }
            
            Logging.Debug($"[RevealableObject] {gameObject.name} Progressive mode initialized: {textureWidth}x{textureHeight} reveal texture");
        }
        
        private void Start()
        {
            if (PulverController.Instance == null)
            {
                Logging.Error($"[RevealableObject] {gameObject.name} cannot start - PulverController not found!");
                return;
            }
            
            // Start mode-specific runtime logic - COMPLETELY SEPARATE
            if (revealMode == RevealMode.Binary)
            {
                StartBinaryModeTracking();
            }
            else if (revealMode == RevealMode.Progressive)
            {
                StartProgressiveModeTracking();
            }
        }
        
        // ========================================
        // BINARY MODE: Start tracking
        // ========================================
        
        private void StartBinaryModeTracking()
        {
            _binaryRevealCoroutine = StartCoroutine(BinaryRevealTrackingCoroutine());
            Logging.Debug($"[RevealableObject] {gameObject.name} Binary mode tracking started");
        }
        
        // ========================================
        // PROGRESSIVE MODE: Start tracking
        // ========================================
        
        private void StartProgressiveModeTracking()
        {
            // Subscribe to movement events for stamping
            PulverController.Instance.OnMovementStarted += OnPlayerMovementStarted;
            PulverController.Instance.OnMovementStopped += OnPlayerMovementStopped;
            
            // NO vision tracking coroutine - Progressive shader does per-pixel distance checks using global _PlayerWorldPos
            
            Logging.Debug($"[RevealableObject] {gameObject.name} Progressive mode tracking started");
        }
        

        // ========================================
        // BINARY MODE: Vision-based reveal coroutine
        // ========================================
        
        /// <summary>
        /// Binary mode coroutine - tracks player distance and updates vision/reveal flags
        /// Runs continuously, checks every 0.1s for performance
        /// </summary>
        private IEnumerator BinaryRevealTrackingCoroutine()
        {
            while (!_isCollected && _instanceMaterial != null)
            {
                // Calculate distance to player
                float distance = Vector2.Distance(transform.position, PulverController.PlayerPosition);
                bool isInRadius = distance < PulverController.VisionRadius;
                
                // Set real-time vision flag (controls shader color vs outline)
                _instanceMaterial.SetFloat(IsInVisionID, isInRadius ? 1f : 0f);
                
                // Set reveal flag (once revealed, stays revealed)
                if (isInRadius && !_hasBeenRevealed)
                {
                    _hasBeenRevealed = true;
                    _instanceMaterial.SetFloat(IsRevealedID, 1f);
                    Logging.Debug($"[RevealableObject] {gameObject.name} revealed!");
                }
                
                // Wait before next check (reduces CPU load)
                yield return new WaitForSeconds(0.1f);
            }
        }
        
        // ========================================
        // PROGRESSIVE MODE: Event-based stamp reveal
        // ========================================
        
        /// <summary>
        /// Called when player starts moving - begin stamping if near object
        /// </summary>
        private void OnPlayerMovementStarted()
        {
            if (_isCollected || revealMode != RevealMode.Progressive) return;
            
            // Check if player's vision circle could overlap with object bounds
            // Use closest point on bounds to check distance
            Vector2 playerPos = PulverController.PlayerPosition;
            Vector2 closestPoint = _objectBounds.ClosestPoint(playerPos);
            float distanceToBounds = Vector2.Distance(playerPos, closestPoint);
            
            // Start stamping if vision radius could reach the object
            // Add padding to account for vision radius overlap
            float activationThreshold = _activationDistance + _objectBounds.extents.magnitude;
            
            if (distanceToBounds < activationThreshold && _stampCoroutine == null)
            {
                _stampCoroutine = StartCoroutine(StampRevealCoroutine());
                Logging.Debug($"[RevealableObject] {gameObject.name} started stamping coroutine (distanceToBounds: {distanceToBounds:F2}, threshold: {activationThreshold:F2})");
            }
        }
        
        /// <summary>
        /// Called when player stops moving - stop stamping
        /// </summary>
        private void OnPlayerMovementStopped()
        {
            if (_stampCoroutine != null)
            {
                StopCoroutine(_stampCoroutine);
                _stampCoroutine = null;
            }
        }
        
        /// <summary>
        /// Coroutine that stamps reveal texture while player is moving and near object
        /// </summary>
        private IEnumerator StampRevealCoroutine()
        {
            while (!_isCollected)
            {
                // Check if player's vision circle overlaps with object bounds
                Vector2 playerPos = PulverController.PlayerPosition;
                Vector2 closestPoint = _objectBounds.ClosestPoint(playerPos);
                float distanceToBounds = Vector2.Distance(playerPos, closestPoint);
                
                // Calculate activation threshold with padding
                float activationThreshold = _activationDistance + _objectBounds.extents.magnitude;
                
                // If player moved too far away, stop stamping
                if (distanceToBounds >= activationThreshold)
                {
                    Logging.Debug($"[RevealableObject] {gameObject.name} stopping stamping coroutine (too far)");
                    _stampCoroutine = null;
                    yield break;
                }
                
                // Stamp if player's vision radius reaches any part of the object
                if (distanceToBounds < PulverController.VisionRadius)
                {
                    StampPlayerPosition();
                }
                
                // Wait before next stamp (reduces GPU writes)
                yield return new WaitForSeconds(0.1f);
            }
        }
        
        /// <summary>
        /// Stamp the player's current position onto the reveal texture
        /// Direct CPU-based stamping - calculates circle-rectangle intersection in world space
        /// </summary>
        private void StampPlayerPosition()
        {
            if (_revealStampTexture == null)
            {
                Logging.Warning($"[RevealableObject] {gameObject.name} cannot stamp: texture is null");
                return;
            }
            
            // Get player position and vision radius in world space
            Vector2 playerWorldPos = PulverController.PlayerPosition;
            float visionRadius = PulverController.VisionRadius;
            
            // Get object bounds in world space
            Vector2 boundsMin = _objectBounds.min;
            Vector2 boundsSize = _objectBounds.size;
            
            // Get texture dimensions
            int texWidth = _revealStampTexture.width;
            int texHeight = _revealStampTexture.height;
            
            // Calculate the bounding box of the circle in world space
            Vector2 circleMin = playerWorldPos - Vector2.one * visionRadius;
            Vector2 circleMax = playerWorldPos + Vector2.one * visionRadius;
            
            // Calculate intersection of circle bounding box with object bounds
            Vector2 intersectMin = new Vector2(
                Mathf.Max(circleMin.x, boundsMin.x),
                Mathf.Max(circleMin.y, boundsMin.y)
            );
            Vector2 intersectMax = new Vector2(
                Mathf.Min(circleMax.x, boundsMin.x + boundsSize.x),
                Mathf.Min(circleMax.y, boundsMin.y + boundsSize.y)
            );
            
            // Check if there's any intersection
            if (intersectMin.x >= intersectMax.x || intersectMin.y >= intersectMax.y)
            {
                return; // No intersection, nothing to stamp
            }
            
            // Convert world space intersection to texture pixel coordinates
            int pixelMinX = Mathf.FloorToInt((intersectMin.x - boundsMin.x) / boundsSize.x * texWidth);
            int pixelMaxX = Mathf.CeilToInt((intersectMax.x - boundsMin.x) / boundsSize.x * texWidth);
            int pixelMinY = Mathf.FloorToInt((intersectMin.y - boundsMin.y) / boundsSize.y * texHeight);
            int pixelMaxY = Mathf.CeilToInt((intersectMax.y - boundsMin.y) / boundsSize.y * texHeight);
            
            // Clamp to texture bounds
            pixelMinX = Mathf.Max(0, pixelMinX);
            pixelMaxX = Mathf.Min(texWidth, pixelMaxX);
            pixelMinY = Mathf.Max(0, pixelMinY);
            pixelMaxY = Mathf.Min(texHeight, pixelMaxY);
            
            // Read current texture data
            RenderTexture.active = _revealStampTexture;
            Texture2D tempTex = new Texture2D(texWidth, texHeight, TextureFormat.R8, false);
            tempTex.ReadPixels(new Rect(0, 0, texWidth, texHeight), 0, 0);
            tempTex.Apply();
            
            // Stamp pixels within the circle
            bool anyPixelStamped = false;
            float radiusSquared = visionRadius * visionRadius;
            
            for (int py = pixelMinY; py < pixelMaxY; py++)
            {
                for (int px = pixelMinX; px < pixelMaxX; px++)
                {
                    // Convert pixel coordinates back to world space
                    float worldX = boundsMin.x + (px / (float)texWidth) * boundsSize.x;
                    float worldY = boundsMin.y + (py / (float)texHeight) * boundsSize.y;
                    
                    // Check if this pixel is within the circle
                    float dx = worldX - playerWorldPos.x;
                    float dy = worldY - playerWorldPos.y;
                    float distSquared = dx * dx + dy * dy;
                    
                    if (distSquared <= radiusSquared)
                    {
                        // Stamp this pixel (set to white)
                        tempTex.SetPixel(px, py, Color.white);
                        anyPixelStamped = true;
                    }
                }
            }
            
            if (anyPixelStamped)
            {
                // Upload modified texture back to GPU
                tempTex.Apply();
                Graphics.CopyTexture(tempTex, _revealStampTexture);
                
                Logging.Debug($"[RevealableObject] {gameObject.name} stamped pixels at world pos ({playerWorldPos.x:F2}, {playerWorldPos.y:F2}), radius {visionRadius:F2}");
            }
            
            RenderTexture.active = null;
            Destroy(tempTex);
        }
        
        private void OnTriggerEnter2D(Collider2D other)
        {
            // Check if player is interacting
            if (other.CompareTag("Player") && _hasBeenRevealed && !_isCollected)
            {
                HandleInteraction();
            }
        }
        
        private void HandleInteraction()
        {
            if (isBoosterPack)
            {
                CollectBoosterPack();
            }
            else if (isExit)
            {
                ActivateExit();
            }
        }
        
        private void CollectBoosterPack()
        {
            _isCollected = true;
            
            Logging.Debug($"[RevealableObject] Booster pack collected: {gameObject.name}");
            
            // Notify controller
            if (TrashMazeController.Instance != null)
            {
                TrashMazeController.Instance.OnBoosterPackCollected();
            }
            
            // Destroy object
            Destroy(gameObject);
        }
        
        private void ActivateExit()
        {
            Logging.Debug($"[RevealableObject] Exit activated: {gameObject.name}");
            
            // Notify controller
            if (TrashMazeController.Instance != null)
            {
                TrashMazeController.Instance.OnExitReached();
            }
        }
        
        private void OnDestroy()
        {
            // Stop Binary mode coroutine
            if (_binaryRevealCoroutine != null)
            {
                StopCoroutine(_binaryRevealCoroutine);
            }
            
            // Unsubscribe from Progressive mode movement events
            if (revealMode == RevealMode.Progressive && PulverController.Instance != null)
            {
                PulverController.Instance.OnMovementStarted -= OnPlayerMovementStarted;
                PulverController.Instance.OnMovementStopped -= OnPlayerMovementStopped;
            }
            
            // Stop Progressive mode stamping coroutine
            if (_stampCoroutine != null)
            {
                StopCoroutine(_stampCoroutine);
            }
            
            // Clean up progressive reveal resources
            if (_revealStampTexture != null)
            {
                _revealStampTexture.Release();
                Destroy(_revealStampTexture);
            }
            

            // Clean up instance material
            if (_instanceMaterial != null)
            {
                Destroy(_instanceMaterial);
            }
        }
        
        /// <summary>
        /// Check if object is currently visible to player
        /// </summary>
        public bool IsVisible()
        {
            float distance = Vector2.Distance(transform.position, PulverController.PlayerPosition);
            return distance < PulverController.VisionRadius;
        }
        
        /// <summary>
        /// Check if object has been revealed at any point
        /// </summary>
        public bool HasBeenRevealed()
        {
            return _hasBeenRevealed;
        }
        
        /// <summary>
        /// Force reveal the object (for debugging or special cases)
        /// </summary>
        public void ForceReveal()
        {
            _hasBeenRevealed = true;
            if (_instanceMaterial != null)
            {
                _instanceMaterial.SetFloat(IsRevealedID, 1f);
            }
        }
    }
}