member, class, combined discount code logic

{% assign member_discount_code = settings.member_discount_code %}
{% assign class_discount_code = settings.class_discount_code %}
{% assign combined_discount_code = settings.combined_discount_code %}

{% if customer %}
  {% assign customer_tags = customer.tags | join:',' | downcase %}
  {% if customer_tags contains 'member' %}
    {% assign member = true %}
  {% endif %}
{% endif %}
{% for item in cart.items %}
  {% if item.product.type == 'class' %}
    {% assign product_tags = item.product.tags | join:',' | downcase %}
    {% if product_tags contains [qualifying_product_tag] %}
      {% assign class_discount = true %}
    {% endif %}
  {% endif %}
{% endfor %}

{% if member %}
  {% if class_discount %}
    {% assign applied_discount = combined_discount_code %}
  {% else %}
    {% assign applied_discount = member_discount_code %}
  {% endif %}
{% else %}
  {% if class_discount %}
    {% assign applied_discount = class_discount_code %}
  {% endif %}
{% endif %}

<form action="{{ routes.cart_url }}{% if applied_discount != blank %}/?discount={{ applied_discount }}{% endif %}" method="post" novalidate class="cart">