private void FixedUpdate()
{
    switch (state)
    {
        case State.Patrolling:
            Patrol();
            break;
    }
}

private void Patrol()
{
    if (state != State.Patrolling)
        return;

    aiDestinationSetter.target = waypoints[waypointIndex];

    if (Vector2.Distance(transform.position, waypoints[waypointIndex].transform.position) <= 0.17f)
        waypointIndex++;

    if (waypointIndex == waypoints.Count)
        waypointIndex = 0;
}