AppleHillsProduction/Assets/Scripts/Minigames/Airplane/Interactive/ParallaxElement.cs

using Core;
using Minigames.Airplane.Data;
using UnityEngine;

namespace Minigames.Airplane.Interactive
{
    /// <summary>
    /// Parallax element that adjusts position based on camera movement.
    /// Creates depth illusion by moving at different speeds for different layers.
    /// Continuously tracks active camera for seamless transitions.
    /// </summary>
    public class ParallaxElement : MonoBehaviour
    {
        [Header("Layer Configuration")]
        [Tooltip("Which parallax layer this element belongs to")]
        [SerializeField] private ParallaxLayer layer = ParallaxLayer.Background;
        
        [Header("Parallax Settings")]
        [Tooltip("Global parallax strength multiplier (0 = no parallax, 1 = full)")]
        [SerializeField] private float globalStrength = 1f;
        
        [Tooltip("Per-layer parallax factors (Background/Middle/Foreground)")]
        [SerializeField] private float backgroundFactor = 0.3f;
        [SerializeField] private float middleFactor = 0.6f;
        [SerializeField] private float foregroundFactor = 0.9f;
        
        [Header("Debug")]
        [SerializeField] private bool showDebugLogs;
        
        private Transform _cameraTransform;
        private Vector3 _startPosition;
        private float _startCameraX;
        private bool _isInitialized;
        
        private void Awake()
        {
            // Ensure correct sort layer
            EnsureSortLayer();
        }
        
        private void Start()
        {
            _startPosition = transform.position;
            
            if (_cameraTransform != null)
            {
                _startCameraX = _cameraTransform.position.x;
                _isInitialized = true;
            }
        }
        
        private void Update()
        {
            if (!_isInitialized || _cameraTransform == null) return;
            
            ApplyParallax();
        }
        
        /// <summary>
        /// Set the parallax layer for this element.
        /// </summary>
        public void SetLayer(ParallaxLayer newLayer)
        {
            layer = newLayer;
            EnsureSortLayer();
            
            if (showDebugLogs)
            {
                Logging.Debug($"[ParallaxElement] Layer set to {layer}");
            }
        }
        
        /// <summary>
        /// Set the camera transform to track.
        /// Call this when camera changes.
        /// </summary>
        public void SetCameraTransform(Transform cameraTransform)
        {
            if (cameraTransform == null) return;
            
            // If camera changed, recalculate base position
            if (_cameraTransform != null && _cameraTransform != cameraTransform)
            {
                // Smooth transition: current world position becomes new start position
                _startPosition = transform.position;
            }
            
            _cameraTransform = cameraTransform;
            _startCameraX = _cameraTransform.position.x;
            _isInitialized = true;
            
            if (showDebugLogs)
            {
                Logging.Debug($"[ParallaxElement] Camera set, starting camera X={_startCameraX:F2}");
            }
        }
        
        private void ApplyParallax()
        {
            // Calculate camera displacement from start
            float cameraDisplacement = _cameraTransform.position.x - _startCameraX;
            
            // Get layer-specific parallax factor
            float layerFactor = GetLayerFactor();
            
            // Calculate parallax offset (reduced displacement based on layer depth)
            float parallaxOffset = cameraDisplacement * layerFactor * globalStrength;
            
            // Apply offset to start position
            Vector3 newPosition = _startPosition;
            newPosition.x += parallaxOffset;
            transform.position = newPosition;
        }
        
        private float GetLayerFactor()
        {
            return layer switch
            {
                ParallaxLayer.Background => backgroundFactor,
                ParallaxLayer.Middle => middleFactor,
                ParallaxLayer.Foreground => foregroundFactor,
                _ => 1f
            };
        }
        
        private void EnsureSortLayer()
        {
            SpriteRenderer spriteRenderer = GetComponentInChildren<SpriteRenderer>();
            if (spriteRenderer == null) return;
            
            // Sort layer is set by spawner, this is just a validation/fallback
            string expectedLayer = layer switch
            {
                ParallaxLayer.Background => "Background",
                ParallaxLayer.Middle => "Midground",
                ParallaxLayer.Foreground => "Foreground",
                _ => "Default"
            };
            
            if (spriteRenderer.sortingLayerName != expectedLayer)
            {
                if (showDebugLogs)
                {
                    Logging.Debug($"[ParallaxElement] Adjusting sort layer to '{expectedLayer}' for {layer}");
                }
            }
        }
    }
}