simple gun

using System;
using System.Collections;
using UnityEngine;
using UnityEngine.InputSystem;

#nullable enable
#pragma warning disable CS8618
public class Gun : MonoBehaviour
{
    bool holdingGun;
    int ammo = 10;

    Transform? gun;
    Transform gunShotPoint;
    [SerializeField] Transform gunHandPoint;

    GameObject flash;
    [SerializeField] GameObject bulletHole;

    [SerializeField] AudioClip gunSound;
    [SerializeField] AudioSource soundSource;

    [SerializeField] LayerMask layerToCheck;

    Vector3 handVelocity;
    Vector3 prevHandPos;

    #region buttons
    public void RightGripButton(InputAction.CallbackContext context)
    {
        if (context.phase == InputActionPhase.Started)
            GrabGun();
        else if (context.phase == InputActionPhase.Canceled)
            DropGun();
    }

    public void RightTriggerButton(InputAction.CallbackContext context)
    {
        if (!holdingGun) return;

        if(context.phase == InputActionPhase.Started)
        {
            ammo--;
            Shoot();
        }
    }
    #endregion

    Transform? FindGun()
    {
        Transform? foundGun = null;

        GameObject[] guns = GameObject.FindGameObjectsWithTag("Gun");
        float highestAngle = 0.45f;

        foreach(GameObject gun in guns)
        {
            Vector3 dir = gun.transform.position - transform.position;
            float angle = Vector3.Dot(-transform.right, dir.normalized);

            if (angle < highestAngle) continue;

            RaycastHit foundObject;
            if(Physics.Raycast(transform.position, dir.normalized, out foundObject, 10, layerToCheck))
            {
                if (foundObject.transform == gun.transform)
                    foundGun = foundObject.transform;
            }
        }

        return foundGun;
    }

    void GrabGun()
    {
        Transform? gun = FindGun();
        if (gun == null) return;

        Tween moveGun = ScriptableObject.CreateInstance<Tween>();
        moveGun.Initiate(gun, gunHandPoint, gunHandPoint.position, 0.25f);
        //Tween.Create(gun, gunHandPoint, gunHandPoint.position, 0.25f);
        StartCoroutine(moveGun.Play(true));

        holdingGun = true;
        gunShotPoint = gun.Find("GunPoint");
        flash = gunShotPoint.Find("GunFlash").gameObject;
        this.gun = gun;
    }

    void DropGun()
    {
        Transform foundGun = transform.Find("gunpos").Find("glock");
        if(foundGun == null) return;

        Rigidbody gunBody = foundGun.GetComponent<Rigidbody>();
        gunBody.freezeRotation = false;
        gunBody.constraints = RigidbodyConstraints.None;
        gunBody.useGravity = true;
        gunBody.velocity = handVelocity/Time.deltaTime;

        foundGun.parent = null;
        gun = null;
    }

    void Shoot()
    {
        RaycastHit hitObject;
        soundSource.Play();
        StartCoroutine(Flash());

        if(Physics.Raycast(gunShotPoint.position, gunShotPoint.forward, out hitObject, Mathf.Infinity))
        {
            GameObject newbullethole = Instantiate(bulletHole);
            Transform bulletData = newbullethole.transform;
            bulletData.position = hitObject.point;
            bulletData.LookAt(bulletData.position + hitObject.normal);
            bulletData.parent = hitObject.transform;

            Color targetColor = hitObject.transform.GetComponent<MeshRenderer>().materials[0].color;
            newbullethole.GetComponent<MeshRenderer>().materials[1].color = targetColor;

            StartCoroutine(RemoveBullethole(bulletData));
        }
    }

    IEnumerator Flash()
    {
        flash.SetActive(true);
        flash.transform.Find("Glow").GetComponent<ParticleSystem>().Play();
        flash.transform.Find("Sparks").GetComponent<ParticleSystem>().Play();

        yield return new WaitForSeconds(.1f);
        flash.SetActive(false);
    }

    IEnumerator RemoveBullethole(Transform bulletHole)
    {
        yield return new WaitForSeconds(3);
        Destroy(bulletHole.gameObject);
    }

    private void Update()
    {
        handVelocity = (transform.position - prevHandPos);
        prevHandPos = transform.position;
    }
}