using RaceFields.Harvesters.AI;
using UnityEngine;
#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem;
#endif

public sealed class MachineGunWeapon : MonoBehaviour
{
    [Header("References")]
    [SerializeField] private Transform aimPivot;
    [SerializeField] private Transform muzzle;
    [SerializeField] private BulletProjectile projectilePrefab;
    [SerializeField] private ParticleSystem muzzleFlash;

    [Header("Targeting")]
    [SerializeField] private float targetSearchRadius = 80f;
    [SerializeField] private float targetHeightOffset = 1.1f;
    [SerializeField] private float aimTurnSpeed = 18f;

    [Header("Shooting")]
    [SerializeField] private float fireRate = 12f;
    [SerializeField] private float damagePerShot = 8f;
    [SerializeField] private float projectileSpeed = 70f;
    [SerializeField] private float projectileLifeTime = 2.5f;
    [SerializeField] private float spreadAngle = 1.2f;

    private Transform ownerRoot;
    private Transform currentTarget;
    private float nextShotTime;

    private void Awake()
    {
        if (aimPivot == null)
            aimPivot = transform;
        if (muzzle == null)
            muzzle = transform;
    }

    private void OnEnable()
    {
        nextShotTime = 0f;
    }

    private void Update()
    {
        AcquireTarget();
        AimAtTarget();

        if (IsFireHeld())
            TryShoot();
    }

    public void SetOwner(Transform owner)
    {
        ownerRoot = owner != null ? owner.root : null;
    }

    private void AcquireTarget()
    {
        if (IsValidTarget(currentTarget))
            return;

        currentTarget = null;
        HarvesterChaseController[] enemies = Object.FindObjectsByType<HarvesterChaseController>(FindObjectsInactive.Exclude, FindObjectsSortMode.None);
        float bestDistanceSqr = targetSearchRadius * targetSearchRadius;
        Vector3 origin = transform.position;

        for (int i = 0; i < enemies.Length; i++)
        {
            if (enemies[i] == null)
                continue;

            Transform candidate = enemies[i].transform;
            float distanceSqr = (candidate.position - origin).sqrMagnitude;
            if (distanceSqr >= bestDistanceSqr)
                continue;

            currentTarget = candidate;
            bestDistanceSqr = distanceSqr;
        }
    }

    private bool IsValidTarget(Transform target)
    {
        if (target == null || !target.gameObject.activeInHierarchy)
            return false;

        return (target.position - transform.position).sqrMagnitude <= targetSearchRadius * targetSearchRadius;
    }

    private void AimAtTarget()
    {
        if (currentTarget == null || aimPivot == null)
            return;

        Vector3 targetPoint = currentTarget.position + Vector3.up * targetHeightOffset;
        Vector3 direction = targetPoint - aimPivot.position;
        if (direction.sqrMagnitude < 0.001f)
            return;

        Quaternion targetRotation = Quaternion.LookRotation(direction.normalized, Vector3.up);
        aimPivot.rotation = Quaternion.Slerp(aimPivot.rotation, targetRotation, aimTurnSpeed * Time.deltaTime);
    }

    private void TryShoot()
    {
        if (Time.time < nextShotTime || projectilePrefab == null)
            return;

        nextShotTime = Time.time + 1f / Mathf.Max(0.01f, fireRate);
        ShootProjectile();
    }

    private void ShootProjectile()
    {
        Vector3 direction = ApplySpread(muzzle.forward);
        BulletProjectile projectile = Instantiate(projectilePrefab, muzzle.position, Quaternion.LookRotation(direction, Vector3.up));
        projectile.Launch(direction * projectileSpeed, damagePerShot, projectileLifeTime, ownerRoot);

        if (muzzleFlash != null)
            muzzleFlash.Play();
    }




    private Vector3 ApplySpread(Vector3 direction)
    {
        if (spreadAngle <= 0f)
            return direction.normalized;

        Quaternion spread = Quaternion.Euler(
            Random.Range(-spreadAngle, spreadAngle),
            Random.Range(-spreadAngle, spreadAngle),
            0f);
        return (spread * direction).normalized;
    }

    private static bool IsFireHeld()
    {
#if ENABLE_INPUT_SYSTEM
        if (Mouse.current != null)
            return Mouse.current.leftButton.isPressed;
#endif
#if ENABLE_LEGACY_INPUT_MANAGER
        return Input.GetMouseButton(0);
#else
        return false;
#endif
    }
}