script.liquid

{% assign ve_product_ids_keyval = options.voucher_product_ids_and_entitled_product_ids__keyval_number_required %}

{% if event.preview or order.customer %}
  {% for order_line_item in order.line_items %}
    {% assign voucher_product_id = order_line_item.product_id %}
    {% assign voucher_product_id_string = voucher_product_id | append: "" %}
    {% assign entitled_product_id = ve_product_ids_keyval[voucher_product_id_string] %}

    {% if event.preview or entitled_product_id %}
      {% for order_line_item_n in (1..order_line_item.quantity) %}
        {% assign discount_code = options.discount_code_prefix__required | append: order.order_number | append: order_line_item.sku | append: order_line_item_n | append: order.customer.id %}

        {% if event.preview or shop.discount_codes[discount_code] == nil %}
          {% assign voucher_product = shop.products[voucher_product_id] %}
          {% assign entitled_product = shop.products[entitled_product_id] %}

          {% assign voucher_product_title = voucher_product.title | default: "(voucher product title)" %}
          {% assign entitled_product_title = entitled_product.title | default: "(entitled product title)" %}
          {% assign entitled_product_admin_graphql_api_id = entitled_product.admin_graphql_api_id %}

          {% assign customer_admin_graphql_api_id = shop.customers[order.customer.id].admin_graphql_api_id %}

          {% capture graphql_query %}
            mutation {
              priceRuleCreate(
                priceRule: {
                  allocationMethod: ACROSS
                  customerSelection: {
                    customerIdsToAdd: [{{ customer_admin_graphql_api_id | json }}]
                  }
                  itemEntitlements:{
                    productIds: [{{ entitled_product_admin_graphql_api_id | json }}]
                  }
                  target: LINE_ITEM
                  title: {{ discount_code | json }}
                  usageLimit: 1
                  validityPeriod: {
                    start: {{ "now" | date: "%FT%T%:z" | json }}
                  }
                  value: {
                    fixedAmountValue: {{ options.discount_value__number_required | json }}
                  }
                }
                priceRuleDiscountCode: {
                  code: {{ discount_code | json }}
                }
              ) {
                priceRule {
                  id
                }
                priceRuleUserErrors {
                  code
                  field
                  message
                }
                priceRuleDiscountCode {
                  code
                  id
                }
              }
            }
          {% endcapture %}

          {
            "action": {
              "type": "shopify",
              "options": {{ graphql_query | json }}
            }
          }

          {% assign email_subject = options.email_subject__required | replace: 'DISCOUNT_CODE', discount_code | replace: 'VOUCHER_PRODUCT_TITLE', voucher_product_title | replace: 'ENTITLED_PRODUCT_TITLE', entitled_product_title %}
          {% assign email_body = options.email_body__multiline_required | replace: 'DISCOUNT_CODE', discount_code | replace: 'VOUCHER_PRODUCT_TITLE', voucher_product_title | replace: 'ENTITLED_PRODUCT_TITLE', entitled_product_title %}

          {
            "action": {
              "type": "email",
              "options": {
                "to": {{ order.email | json }},
                "subject": {{ email_subject | strip | json }},
                "body": {{ email_body | newline_to_br | json }},
                "reply_to": {{ shop.customer_email | json }},
                "from_display_name": {{ shop.name | json }}
              }
            }
          }
        {% else %}
          {"log": {{ discount_code | append: " already exists; skipping" | json }}}
        {% endif %}
      {% endfor %}
    {% endif %}

    {% if event.preview %}
      {% break %}
    {% endif %}
  {% endfor %}
{% endif %}