using UnityEngine;

namespace Minigames.Airplane.Interactive
{
    /// <summary>
    /// Gravity well that pulls airplanes toward its Y position (vertical only).
    /// Plane below the well gets pulled UP, plane above gets pulled DOWN.
    /// Does NOT affect horizontal (X) velocity - plane maintains forward momentum.
    /// Creates challenging "danger zones" that players must avoid or escape from.
    /// </summary>
    [RequireComponent(typeof(Collider2D))]
    public class AirplaneGravityWell : MonoBehaviour, ISpawnInitializable
    {
        [Header("Gravity Configuration")]
        [SerializeField] private float pullStrength = 5f;
        [SerializeField] private bool useInverseSquare = false;
        [SerializeField] private float minPullDistance = 0.5f;
        
        [Header("Optional Modifiers")]
        [SerializeField] private float maxPullForce = 15f;
        [SerializeField] private AnimationCurve pullFalloff = AnimationCurve.Linear(0, 1, 1, 0);
        
        [Header("Visual Feedback (Optional)")]
        [SerializeField] private ParticleSystem gravityParticles;
        [SerializeField] private SpriteRenderer centerSprite;
        [SerializeField] private float rotationSpeed = 90f;
        
        [Header("Debug")]
        [SerializeField] private bool showDebugLogs;
        [SerializeField] private bool drawDebugLines = true;
        
        private Vector2 centerPosition;
        
        private void Awake()
        {
            // Ensure collider is trigger
            var collider = GetComponent<Collider2D>();
            if (collider != null)
            {
                collider.isTrigger = true;
            }
        }
        
        /// <summary>
        /// Called by spawn manager after object is positioned.
        /// Caches the final Y position for pull calculations.
        /// </summary>
        public void Initialize()
        {
            centerPosition = transform.position;
        }
        
        private void Update()
        {
            // Rotate center visual if present
            if (centerSprite != null)
            {
                centerSprite.transform.Rotate(0, 0, rotationSpeed * Time.deltaTime);
            }
        }
        
        private void OnTriggerStay2D(Collider2D other)
        {
            // Check if it's an airplane
            var airplane = other.GetComponent<Core.AirplaneController>();
            if (airplane == null || !airplane.IsFlying) return;
            
            var rb = other.GetComponent<Rigidbody2D>();
            if (rb == null) return;
            
            // Calculate VERTICAL distance only (Y-axis only)
            Vector2 airplanePos = rb.position;
            float yDistance = centerPosition.y - airplanePos.y;
            float absYDistance = Mathf.Abs(yDistance);
            
            // Prevent division by zero
            if (absYDistance < minPullDistance)
            {
                absYDistance = minPullDistance;
            }
            
            // Calculate pull force based on vertical distance
            float forceMagnitude;
            
            if (useInverseSquare)
            {
                // Realistic gravity-like force (inverse square law)
                forceMagnitude = pullStrength / (absYDistance * absYDistance);
            }
            else
            {
                // Linear falloff based on vertical distance
                var collider = GetComponent<Collider2D>();
                float maxDistance = collider != null ? collider.bounds.extents.y * 2f : 5f; // Use height, not diagonal
                float normalizedDistance = Mathf.Clamp01(absYDistance / maxDistance);
                float falloff = pullFalloff.Evaluate(1f - normalizedDistance);
                forceMagnitude = pullStrength * falloff;
            }
            
            // Clamp force
            forceMagnitude = Mathf.Min(forceMagnitude, maxPullForce);
            
            // Apply force ONLY in Y direction, toward the well's Y position
            // If plane is below (yDistance > 0), pull up (+Y)
            // If plane is above (yDistance < 0), pull down (-Y)
            float yForceDirection = yDistance > 0 ? 1f : -1f;
            Vector2 pullForce = new Vector2(0f, yForceDirection * forceMagnitude);
            rb.AddForce(pullForce, ForceMode2D.Force);
            
            if (showDebugLogs && Time.frameCount % 30 == 0) // Log every 30 frames
            {
                Debug.Log($"[AirplaneGravityWell] Pulling {other.name}: force={forceMagnitude:F2} {(yForceDirection > 0 ? "UP" : "DOWN")}, Y-distance={absYDistance:F2}");
            }
        }
        
        private void OnDrawGizmos()
        {
            // Visualize gravity well in editor
            Gizmos.color = new Color(1f, 0f, 1f, 0.3f); // Magenta transparent
            
            var collider = GetComponent<Collider2D>();
            if (collider != null)
            {
                // Draw zone bounds
                Gizmos.DrawWireSphere(collider.bounds.center, collider.bounds.extents.magnitude);
                
                // Draw center point
                Gizmos.color = Color.magenta;
                Gizmos.DrawWireSphere(transform.position, 0.5f);
                
                // Draw pull strength indicator
                Gizmos.DrawRay(transform.position, Vector3.up * pullStrength * 0.2f);
            }
        }
        
        private void OnDrawGizmosSelected()
        {
            if (!drawDebugLines) return;
            
            // Draw pull force visualization at multiple points
            var collider = GetComponent<Collider2D>();
            if (collider == null) return;
            
            float radius = collider.bounds.extents.magnitude;
            int samples = 8;
            
            for (int i = 0; i < samples; i++)
            {
                float angle = (i / (float)samples) * 360f * Mathf.Deg2Rad;
                Vector2 offset = new Vector2(Mathf.Cos(angle), Mathf.Sin(angle)) * radius;
                Vector3 samplePoint = transform.position + (Vector3)offset;
                Vector3 direction = (transform.position - samplePoint).normalized;
                
                Gizmos.color = Color.yellow;
                Gizmos.DrawLine(samplePoint, samplePoint + direction * 2f);
            }
        }
    }
}