Enemy script.

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

[RequireComponent(typeof(NavMeshAgent))]
public class Enemy : LivingEntity {

    public enum state { idle, chase, attack};

    private state currentState;
    private NavMeshAgent pathFinder;
    private Transform target;
    private float attackThreshhold = .5f;
    private float timeBetweenAttacks = 1;
    private float attackTimer;
    private float myCollisionRadius;
    private float targetCollisionRadius;


    // Start is called before the first frame update
    protected override void Start() {

        base.Start();
        currentState = state.chase;
        pathFinder = GetComponent<NavMeshAgent>();
        target = GameObject.FindGameObjectWithTag("Player").transform;
        myCollisionRadius = GetComponent<CapsuleCollider>().radius;
        targetCollisionRadius = GetComponent<CapsuleCollider>().radius;



        StartCoroutine(updatePath());
    }

    // Update is called once per frame
    void Update() {

        if(Time.time > attackTimer)
        {
            float sqrDistanceToTarget = (target.position - transform.position).sqrMagnitude;
            if (sqrDistanceToTarget < Mathf.Pow(attackThreshhold + myCollisionRadius + targetCollisionRadius, 2)) {
                attackTimer = Time.time + timeBetweenAttacks;
                StartCoroutine(attack());
            }
        }
    }

    IEnumerator attack() {

        currentState = state.attack;
        pathFinder.enabled = false;

        Vector3 origin = transform.position;
        Vector3 attackPos = target.position;
        float percent = 0;
        float attackSpeed = 3;

        while(percent <= 1) {

            percent += Time.deltaTime * attackSpeed;
            float interpolation = (-Mathf.Pow(percent, 2) + percent) * 4;
            transform.position = Vector3.Lerp(origin, attackPos, interpolation);

            yield return null;
        }
        currentState = state.chase;
        pathFinder.enabled = true;
    }

    IEnumerator updatePath() {

        float refreshRate = .25f;

        while(target != null) {
            if(currentState == state.chase) {
                Vector3 dirToTarget = (target.position - transform.position).normalized;
                Vector3 targetPosition = target.position - dirToTarget * (myCollisionRadius + targetCollisionRadius/2);
                if (!dead) pathFinder.SetDestination(targetPosition);
                yield return new WaitForSeconds(refreshRate);
            }

        }

    }
}