using UnityEngine;

public class Projectile : MonoBehaviour
{
    [Header("Projectile Settings")]
    [Tooltip("How fast the projectile moves forward")]
    public float speed = 25f;
    
    [Tooltip("How long before the projectile destroys itself if it misses")]
    public float lifetime = 5f;

    [Tooltip("Offset for embedding the arrow into the target so it doesn't just stick on the very edge")]
    public float embedDepth = 0.2f;

    [Header("Loaded Offsets (Before Firing)")]
    [Tooltip("Adjust this to fix how the arrow sits in the hand before it is fired")]
    public Vector3 loadedPositionOffset = Vector3.zero;
    public Vector3 loadedRotationOffset = Vector3.zero;

    private float _damage;
    private LayerMask _targetLayers;
    private bool _hasHit;
    private Vector3 _lastPosition;

    public void Initialize(float damage, LayerMask targets)
    {
        _damage = damage;
        _targetLayers = targets;
        
        // Destroy the arrow after a few seconds if it flies into the sky
        Destroy(gameObject, lifetime);
    }

    private void Start()
    {
        _lastPosition = transform.position;
    }

    private void Update()
    {
        if (_hasHit) return;

        // Move the projectile forward
        Vector3 direction = transform.forward;
        float distance = speed * Time.deltaTime;
        transform.position += direction * distance;

        // Raycast from the previous position to the new position to detect hits
        // This prevents fast-moving arrows from passing straight through thin walls or enemies
        if (Physics.Raycast(_lastPosition, direction, out RaycastHit hit, distance, _targetLayers))
        {
            HandleHit(hit);
        }

        _lastPosition = transform.position;
    }

    private void HandleHit(RaycastHit hit)
    {
        _hasHit = true;
        
        // Move the arrow right exactly to the hit point, then embed it slightly
        transform.position = hit.point + (transform.forward * embedDepth);

        // Parent the arrow to the object it hit so it sticks and moves with it
        transform.SetParent(hit.collider.transform, true);

        // If your Arrow Prefab has a Rigidbody on it, it will fall down due to gravity even after being parented!
        // We must destroy the Rigidbody component so it stays perfectly glued to the target.
        Rigidbody rb = GetComponent<Rigidbody>();
        if (rb != null)
        {
            Destroy(rb);
        }

        // Deal damage
        Debug.Log($"Arrow hit {hit.collider.name} for {_damage} damage!");
        hit.collider.GetComponent<WorldObject>()?.TakeDamage(_damage);

        // Optional: Disable collider or script so it doesn't keep checking for hits
        Collider myCollider = GetComponent<Collider>();
        if (myCollider != null) myCollider.enabled = false;
        
        this.enabled = false; // Stops the Update loop
    }
}