enemy

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class EnemyAI : MonoBehaviour
{
    public float moveSpeed = 2f;
    public float patrolDistance = 5f;
    public float shootingDistance = 3f;
    public float bulletSpeed = 5f;
    public GameObject bulletPrefab;
    public Transform firePoint;

    private Vector2 startPosition;
    private bool movingRight = true;
    private Transform player;

    // Start is called before the first frame update
    void Start()
    {
        startPosition = transform.position;
        player = GameObject.FindGameObjectWithTag("Player").transform;
    }

    // Update is called once per frame
    void Update()
    {
        Patrol();
        Shoot();
    }

    void Patrol()
    {
        if (movingRight)
        {
            transform.position = new Vector2(transform.position.x + moveSpeed * Time.deltaTime, transform.position.y);
            if (Vector2.Distance(transform.position, startPosition) >= patrolDistance)
            {
                movingRight = false;
                Flip();
            }
        }
        else
        {
            transform.position = new Vector2(transform.position.x - moveSpeed * Time.deltaTime, transform.position.y);
            if (Vector2.Distance(transform.position, startPosition) >= patrolDistance)
            {
                movingRight = true;
                Flip();
            }
        }
    }

    void Shoot()
    {
        if (Vector2.Distance(transform.position, player.position) <= shootingDistance)
        {
            GameObject bullet = Instantiate(bulletPrefab, firePoint.position, firePoint.rotation);
            Rigidbody2D rb = bullet.GetComponent<Rigidbody2D>();
            rb.AddForce(firePoint.right * bulletSpeed, ForceMode2D.Impulse);
        }
    }

    void Flip()
    {
        Vector3 scale = transform.localScale;
        scale.x *= -1;
        transform.localScale = scale;
    }
}
```

This code creates an enemy AI that patrols back and forth between two points `patrolDistance` units apart. When the player comes within `shootingDistance` units of the enemy, the enemy will shoot a bullet at the player. The `bulletPrefab` variable should be assigned to a prefab object representing the bullet in the Unity Editor.