using UnityEngine;

public class Projectile : MonoBehaviour
{
    [Header("Flight Settings")]
    [SerializeField] private float speed = 50f;
    [SerializeField] private float lifeTime = 5f;
    [SerializeField] private bool usePhysics = false;

    [Header("Damage Settings")]
    [SerializeField] private int damage = 50;
    [SerializeField] private bool isExplosive = false;
    [SerializeField] private float explosionRadius = 4f;
    [SerializeField] private LayerMask damageableLayers = ~0;

    [Header("Visual & Audio Effects")]
    [SerializeField] private GameObject impactEffectPrefab;
    [SerializeField] private AudioClip impactSound;

    private Rigidbody rb;
    private string ownerTag = "Player";
    private bool hasImpacted = false;

    private void Awake()
    {
        rb = GetComponent<Rigidbody>();
        if (rb != null)
        {
            rb.useGravity = usePhysics;
            if (usePhysics)
            {
                rb.linearVelocity = transform.forward * speed;
            }
        }
    }

    private void Start()
    {
        Destroy(gameObject, lifeTime);
    }

    private void Update()
    {
        if (!usePhysics || rb == null)
        {
            // Manual kinematic translation with raycast sweep to prevent tunneling
            float step = speed * Time.deltaTime;
            Ray ray = new Ray(transform.position, transform.forward);

            if (Physics.Raycast(ray, out RaycastHit hit, step, damageableLayers, QueryTriggerInteraction.Ignore))
            {
                if (hit.collider.CompareTag(ownerTag)) return;

                transform.position = hit.point;
                OnHit(hit.collider, hit.point, hit.normal);
                return;
            }

            transform.position += transform.forward * step;
        }
    }

    public void Initialize(int customDamage, float customSpeed, string shooterTag)
    {
        damage = customDamage;
        speed = customSpeed;
        ownerTag = shooterTag;

        if (rb != null && usePhysics)
        {
            rb.linearVelocity = transform.forward * speed;
        }
    }

    private void OnTriggerEnter(Collider other)
    {
        if (hasImpacted || other.CompareTag(ownerTag)) return;
        HandleCollision(other, transform.position, -transform.forward);
    }

    private void OnCollisionEnter(Collision collision)
    {
        if (hasImpacted || collision.collider.CompareTag(ownerTag)) return;

        ContactPoint contact = collision.GetContact(0);
        HandleCollision(collision.collider, contact.point, contact.normal);
    }

    private void OnHit(Collider hitCollider, Vector3 hitPoint, Vector3 hitNormal)
    {
        if (hasImpacted) return;
        HandleCollision(hitCollider, hitPoint, hitNormal);
    }

    private void HandleCollision(Collider hitCollider, Vector3 hitPoint, Vector3 hitNormal)
    {
        hasImpacted = true;

        if (isExplosive)
        {
            Explode(hitPoint);
        }
        else
        {
            // Direct hit damage
            if (hitCollider.TryGetComponent<EnemyController>(out var enemy))
            {
                enemy.TakeDamage(damage);
            }
            else if (hitCollider.TryGetComponent<PlayerHealthController>(out var playerHealth))
            {
                playerHealth.TakeDamage(damage);
            }
        }

        // Spawn visual impact effect
        if (impactEffectPrefab != null)
        {
            Quaternion rot = hitNormal != Vector3.zero ? Quaternion.LookRotation(hitNormal) : Quaternion.identity;
            GameObject impact = Instantiate(impactEffectPrefab, hitPoint, rot);
            Destroy(impact, 2.5f);
        }

        // Play impact sound
        if (impactSound != null)
        {
            AudioSource.PlayClipAtPoint(impactSound, hitPoint);
        }

        Destroy(gameObject);
    }

    private void Explode(Vector3 center)
    {
        Collider[] hits = Physics.OverlapSphere(center, explosionRadius, damageableLayers);
        foreach (Collider col in hits)
        {
            if (col.CompareTag(ownerTag)) continue;

            if (col.TryGetComponent<EnemyController>(out var enemy))
            {
                float distance = Vector3.Distance(center, col.transform.position);
                float damageFalloff = Mathf.Clamp01(1f - (distance / explosionRadius));
                int finalDamage = Mathf.RoundToInt(damage * damageFalloff);
                enemy.TakeDamage(Mathf.Max(1, finalDamage));
            }
            else if (col.TryGetComponent<PlayerHealthController>(out var playerHealth))
            {
                float distance = Vector3.Distance(center, col.transform.position);
                float damageFalloff = Mathf.Clamp01(1f - (distance / explosionRadius));
                int finalDamage = Mathf.RoundToInt(damage * damageFalloff);
                playerHealth.TakeDamage(Mathf.Max(1, finalDamage));
            }
        }
    }

    private void OnDrawGizmosSelected()
    {
        if (isExplosive)
        {
            Gizmos.color = Color.red;
            Gizmos.DrawWireSphere(transform.position, explosionRadius);
        }
    }
}