using AppleHills.Core;
using UnityEngine;
using System;
using Core;

namespace AppleHillsCamera
{
    /// <summary>
    /// Anchors a game object at a fixed distance from a screen edge.
    /// </summary>
    [ExecuteInEditMode] // Make it run in the editor
    public class EdgeAnchor : MonoBehaviour
    {
        // Event that fires when the anchor's position is updated
        public event Action OnPositionUpdated;
        
        public enum AnchorEdge
        {
            Top,
            Bottom,
            Left,
            Right
        }

        [Tooltip("Reference marker that defines the screen edges and margins")]
        public ScreenReferenceMarker referenceMarker;
        
        [Tooltip("Camera adapter to subscribe to for runtime updates")]
        public CameraScreenAdapter cameraAdapter;
        
        [Tooltip("Which screen edge to anchor to")]
        public AnchorEdge anchorEdge = AnchorEdge.Top;
        
        [Tooltip("Whether to use the predefined margin from the reference marker")]
        public bool useReferenceMargin = true;
        
        [Tooltip("Custom margin to use if not using the reference margin")]
        public float customMargin = 1f;
        
        [Tooltip("Whether to adjust the position automatically on Start")]
        public bool adjustOnStart = true;
        
        [Tooltip("Whether to adjust the position when the screen size changes")]
        public bool adjustOnScreenResize = true;
        
        [Tooltip("Whether to preserve the object's position on other axes")]
        public bool preserveOtherAxes = true;
        
        [Tooltip("Whether to account for this object's size in positioning")]
        public bool accountForObjectSize = true;
        
        [Header("Visualization")]
        [Tooltip("Whether to show the anchor visualization in the editor")]
        public bool showVisualization = true;
        
        [Tooltip("Color for the anchor visualization line")]
        public Color visualizationColor = new Color(1f, 0f, 0f, 0.8f);
        
        [Tooltip("Show object bounds in visualization")]
        public bool showObjectBounds = true;
        
        [Tooltip("Debug mode - print position changes to console")]
        public bool debugMode = false;

        private Camera _camera;
        private int _lastScreenWidth;
        private int _lastScreenHeight;
        private float _lastOrthoSize = 0f;
        private Vector3 _originalPosition;
        private bool _initialized = false;
        private Bounds _objectBounds;
        
#if UNITY_EDITOR
        private void OnDrawGizmos()
        {
            if (!showVisualization || referenceMarker == null)
                return;
                
            // Find camera if needed
            if (_camera == null)
                FindCamera();
                
            if (_camera == null)
                return;
                
            // Calculate the anchor point (the exact point on the screen edge)
            Vector3 anchorPoint = CalculateScreenEdgePoint();
            
            // Save original color
            Color originalColor = Gizmos.color;
            
            // Draw line to anchor point
            Gizmos.color = visualizationColor;
            Gizmos.DrawLine(transform.position, anchorPoint);
            
            // Draw a small sphere at the anchor point
            Gizmos.DrawSphere(anchorPoint, 0.1f);
            
            // Draw object bounds if enabled
            if (showObjectBounds && accountForObjectSize)
            {
                Bounds bounds = GetObjectBounds();
                if (bounds.size != Vector3.zero)
                {
                    Color boundsColor = visualizationColor;
                    boundsColor.a *= 0.3f;
                    Gizmos.color = boundsColor;
                    Gizmos.DrawWireCube(bounds.center, bounds.size);
                }
            }
            
            // Restore original color
            Gizmos.color = originalColor;
        }
#endif

        private void Awake()
        {
            _originalPosition = transform.position;
            FindCamera();
            if (_camera != null)
            {
                _lastOrthoSize = _camera.orthographicSize;
            }
            _lastScreenWidth = Screen.width;
            _lastScreenHeight = Screen.height;
            _initialized = true;
        }
        
        private void OnEnable()
        {
            if (!_initialized)
            {
                _originalPosition = transform.position;
                FindCamera();
                _lastScreenWidth = Screen.width;
                _lastScreenHeight = Screen.height;
                _initialized = true;
            }
            
            // Subscribe to camera adapter events
            if (Application.isPlaying && cameraAdapter != null)
            {
                cameraAdapter.OnCameraAdjusted += HandleCameraAdjusted;
            }
            
            // Adjust position immediately when enabled in editor
#if UNITY_EDITOR
            if (!Application.isPlaying)
            {
                UpdatePosition();
            }
#endif
        }
        
        private void OnDisable()
        {
            // Unsubscribe from camera adapter events
            if (cameraAdapter != null)
            {
                cameraAdapter.OnCameraAdjusted -= HandleCameraAdjusted;
            }
        }
        
        private void HandleCameraAdjusted()
        {
            // Update position when camera is adjusted
            if (Application.isPlaying)
            {
                if (debugMode)
                {
                    Logging.Debug($"Camera adjusted event received by {gameObject.name}, updating position");
                }
                
                // Ensure we have the latest camera reference
                FindCamera();
                UpdatePosition();
            }
        }
        
        private void Start()
        {
            // If no camera adapter was manually set, try to find one in the scene
            if (cameraAdapter == null && Application.isPlaying)
            {
                FindCameraAdapter();
            }
            
            // Ensure we're subscribed to camera adapter events
            if (cameraAdapter != null && Application.isPlaying)
            {
                cameraAdapter.OnCameraAdjusted -= HandleCameraAdjusted; // Remove any duplicate subscriptions
                cameraAdapter.OnCameraAdjusted += HandleCameraAdjusted; // Subscribe
            }
            
            if (adjustOnStart && Application.isPlaying)
            {
                UpdatePosition();
            }
        }
        
        private void FindCameraAdapter()
        {
            // Try to find the camera adapter in the scene
            var adapters = FindObjectsOfType<CameraScreenAdapter>();
            if (adapters != null && adapters.Length > 0)
            {
                // Prioritize any adapter that's on the same camera we're using
                foreach (var adapter in adapters)
                {
                    if (_camera != null && adapter.GetControlledCamera() == _camera)
                    {
                        cameraAdapter = adapter;
                        Logging.Debug($"EdgeAnchor on {gameObject.name} auto-connected to CameraScreenAdapter on {cameraAdapter.gameObject.name}");
                        return;
                    }
                }
                
                // If no matching camera found, use the first one
                cameraAdapter = adapters[0];
                Logging.Debug($"EdgeAnchor on {gameObject.name} auto-connected to CameraScreenAdapter on {cameraAdapter.gameObject.name}");
            }
        }
        
        private void Update()
        {
            bool shouldUpdate = false;
            
            // Check if we have a valid camera
            if (_camera == null)
            {
                FindCamera();
                if (_camera != null) shouldUpdate = true;
            }
            
            // Check if camera's ortho size has changed
            if (_camera != null && _camera.orthographicSize != _lastOrthoSize)
            {
                if (debugMode)
                {
                    Logging.Debug($"{gameObject.name}: Camera ortho size changed from {_lastOrthoSize} to {_camera.orthographicSize}");
                }
                _lastOrthoSize = _camera.orthographicSize;
                shouldUpdate = true;
            }
            
            // Update if screen size has changed
            if (adjustOnScreenResize && 
                (Screen.width != _lastScreenWidth || Screen.height != _lastScreenHeight))
            {
                shouldUpdate = true;
                _lastScreenWidth = Screen.width;
                _lastScreenHeight = Screen.height;
            }
            
            // In editor, check for reference marker changes or inspector changes
#if UNITY_EDITOR
            if (!Application.isPlaying)
            {
                shouldUpdate = true;
            }
#endif
            
            // Update position if needed
            if (shouldUpdate)
            {
                UpdatePosition();
            }
        }
        
        private void FindCamera()
        {
            Camera prevCamera = _camera;
            
            // First check if we have a camera adapter reference
            if (cameraAdapter != null)
            {
                _camera = cameraAdapter.GetControlledCamera();
                if (_camera != null)
                {
                    return;
                }
            }
            
            // Look for the main camera
            _camera = Camera.main;
            
            // If no main camera found, try to find any camera
            if (_camera == null)
            {
                _camera = FindAnyObjectByType<Camera>();
            }
            
            if (_camera == null)
            {
                Debug.LogError("EdgeAnchor: No camera found in the scene.");
            }
            else if (_camera != prevCamera && debugMode)
            {
                Logging.Debug($"{gameObject.name}: Camera reference updated to {_camera.name}");
            }
        }
        
        /// <summary>
        /// Get the combined bounds of all renderers on this object and its children
        /// </summary>
        private Bounds GetObjectBounds()
        {
            Bounds bounds = new Bounds(transform.position, Vector3.zero);
            
            // Get all renderers in this object and its children
            Renderer[] renderers = GetComponentsInChildren<Renderer>();
            
            if (renderers.Length > 0)
            {
                // Start with the first renderer's bounds
                bounds = renderers[0].bounds;
                
                // Expand to include all other renderers
                for (int i = 1; i < renderers.Length; i++)
                {
                    bounds.Encapsulate(renderers[i].bounds);
                }
            }
            else
            {
                // No renderers found, create a small placeholder bounds
                bounds = new Bounds(transform.position, new Vector3(0.1f, 0.1f, 0.1f));
            }
            
            // Cache the bounds
            _objectBounds = bounds;
            
            return bounds;
        }
        
        /// <summary>
        /// Manually trigger position adjustment based on the anchor settings.
        /// </summary>
        public void UpdatePosition()
        {
            if (referenceMarker == null)
            {
                Logging.Warning("EdgeAnchor: Missing reference marker.");
                return;
            }
            
            if (_camera == null)
            {
                FindCamera();
                if (_camera == null) return;
            }
            
            // Get the margin value to use
            float margin = GetMarginValue();
            
            // Calculate the new position based on anchor edge and object size
            Vector3 newPosition = CalculateAnchoredPosition(margin);
            
            // If preserving other axes, keep their original values
            if (preserveOtherAxes)
            {
                switch (anchorEdge)
                {
                    case AnchorEdge.Top:
                    case AnchorEdge.Bottom:
                        newPosition.x = transform.position.x;
                        newPosition.z = transform.position.z;
                        break;
                    case AnchorEdge.Left:
                    case AnchorEdge.Right:
                        newPosition.y = transform.position.y;
                        newPosition.z = transform.position.z;
                        break;
                }
            }
            
            // Apply the new position
            if (debugMode && Vector3.Distance(transform.position, newPosition) > 0.01f)
            {
                Logging.Debug($"{gameObject.name} position updated: {transform.position} -> {newPosition}, Camera OrthoSize: {_camera.orthographicSize}");
            }
            
            transform.position = newPosition;
            
            // Notify listeners that the position has been updated
            OnPositionUpdated?.Invoke();
            
            // Store the current ortho size for change detection
            if (_camera != null)
            {
                _lastOrthoSize = _camera.orthographicSize;
            }
        }
        
        private float GetMarginValue()
        {
            if (!useReferenceMargin)
            {
                return customMargin;
            }
            
            switch (anchorEdge)
            {
                case AnchorEdge.Top:
                    return referenceMarker.topMargin;
                case AnchorEdge.Bottom:
                    return referenceMarker.bottomMargin;
                case AnchorEdge.Left:
                    return referenceMarker.leftMargin;
                case AnchorEdge.Right:
                    return referenceMarker.rightMargin;
                default:
                    return customMargin;
            }
        }
        
        private Vector3 CalculateAnchoredPosition(float margin)
        {
            if (_camera == null)
                return transform.position;
                
            // Always get the CURRENT camera properties to ensure we have latest values
            float cameraOrthoSize = _camera.orthographicSize;
            float screenAspect = (float)Screen.width / Screen.height;
            float screenHeight = cameraOrthoSize * 2f;
            float screenWidth = screenHeight * screenAspect;
            
            Vector3 cameraPosition = _camera.transform.position;
            Vector3 newPosition = transform.position;
            
            // Calculate object size offset if needed
            float offsetX = 0f;
            float offsetY = 0f;
            
            if (accountForObjectSize)
            {
                Bounds bounds = GetObjectBounds();
                Vector3 extents = bounds.extents; // Half the size
                Vector3 centerOffset = bounds.center - transform.position; // Offset from pivot to center
                
                switch (anchorEdge)
                {
                    case AnchorEdge.Top:
                        // For top edge, offset is negative (moving down) by the top extent
                        offsetY = -extents.y - centerOffset.y;
                        break;
                    case AnchorEdge.Bottom:
                        // For bottom edge, offset is positive (moving up) by the bottom extent
                        offsetY = extents.y - centerOffset.y;
                        break;
                    case AnchorEdge.Left:
                        // For left edge, offset is positive (moving right) by the left extent
                        offsetX = extents.x - centerOffset.x;
                        break;
                    case AnchorEdge.Right:
                        // For right edge, offset is negative (moving left) by the right extent
                        offsetX = -extents.x - centerOffset.x;
                        break;
                }
            }
            
            switch (anchorEdge)
            {
                case AnchorEdge.Top:
                    // Position from the top of the screen
                    // When margin is 0, object's top edge is exactly at the top screen edge
                    newPosition.y = cameraPosition.y + cameraOrthoSize - margin + offsetY;
                    break;
                
                case AnchorEdge.Bottom:
                    // Position from the bottom of the screen
                    // When margin is 0, object's bottom edge is exactly at the bottom screen edge
                    newPosition.y = cameraPosition.y - cameraOrthoSize + margin + offsetY;
                    break;
                
                case AnchorEdge.Left:
                    // Position from the left of the screen
                    // When margin is 0, object's left edge is exactly at the left screen edge
                    newPosition.x = cameraPosition.x - (screenWidth / 2f) + margin + offsetX;
                    break;
                
                case AnchorEdge.Right:
                    // Position from the right of the screen
                    // When margin is 0, object's right edge is exactly at the right screen edge
                    newPosition.x = cameraPosition.x + (screenWidth / 2f) - margin + offsetX;
                    break;
            }
            
            return newPosition;
        }
        
        /// <summary>
        /// Calculates the exact point on the screen edge for visualization purposes
        /// </summary>
        private Vector3 CalculateScreenEdgePoint()
        {
            if (_camera == null)
                return transform.position;
                
            // Get the screen edges in world coordinates
            float cameraOrthoSize = _camera.orthographicSize;
            float screenAspect = (float)Screen.width / Screen.height;
            float screenHeight = cameraOrthoSize * 2f;
            float screenWidth = screenHeight * screenAspect;
            
            Vector3 cameraPosition = _camera.transform.position;
            Vector3 objectPosition = transform.position;
            
            // Calculate the point exactly on the screen edge that corresponds to the object's anchor
            switch (anchorEdge)
            {
                case AnchorEdge.Top:
                    // Point on top edge with same X coordinate as the object
                    return new Vector3(
                        objectPosition.x, 
                        cameraPosition.y + cameraOrthoSize,
                        objectPosition.z
                    );
                
                case AnchorEdge.Bottom:
                    // Point on bottom edge with same X coordinate as the object
                    return new Vector3(
                        objectPosition.x, 
                        cameraPosition.y - cameraOrthoSize,
                        objectPosition.z
                    );
                
                case AnchorEdge.Left:
                    // Point on left edge with same Y coordinate as the object
                    return new Vector3(
                        cameraPosition.x - (screenWidth / 2f),
                        objectPosition.y,
                        objectPosition.z
                    );
                
                case AnchorEdge.Right:
                    // Point on right edge with same Y coordinate as the object
                    return new Vector3(
                        cameraPosition.x + (screenWidth / 2f),
                        objectPosition.y,
                        objectPosition.z
                    );
                
                default:
                    return objectPosition;
            }
        }
    }
}