Send your customers reorder reminders, with Mechanic.

{% if options.test_mode__boolean %}
  mechanic/user/trigger
{% endif %}
mechanic/scheduler/daily
mechanic/shopify/bulk_operation

{% assign only_include_customers_having_this_tag = options.only_include_customers_having_this_tag %}
{% assign interval_d = options.number_of_days_to_wait_between_emails__number_required %}
{% assign email_subject = options.email_subject__required %}
{% assign email_body = options.email_body__multiline_required %}
{% assign test_mode = options.test_mode__boolean %}

{%- capture cutoff_days -%}
  -{{ interval_d }} days
{%- endcapture -%}
{% assign cutoff_date = "now" | date: "%F", advance: cutoff_days %}

{% if event.topic contains "mechanic/scheduler/" or event.topic == "mechanic/user/trigger" %}
  {%- capture search_query -%}
    last_order_date <= {{ cutoff_date }}
    {%- if only_include_customers_having_this_tag != blank %} AND customer_tags CONTAINS '{{ only_include_customers_having_this_tag }}'{%- endif -%}
  {%- endcapture -%}

  {% log customers_search_query: search_query %}

  {% capture bulk_operation_query %}
    query {
      customerSegmentMembers(
        query: {{ search_query | json }}
      ) {
        edges {
          node {
            __typename
            id
            defaultEmailAddress {
              emailAddress
            }
            lastOrderId
          }
        }
      }
    }
  {% endcapture %}

  {% action "shopify" %}
    mutation {
      bulkOperationRunQuery(
        query: {{ bulk_operation_query | json }}
      ) {
        bulkOperation {
          id
          status
        }
        userErrors {
          field
          message
        }
      }
    }
  {% endaction %}

{% elsif event.topic == "mechanic/shopify/bulk_operation" %}
  {% if event.preview %}
    {% capture jsonl_string %}
      {"__typename":"CustomerSegmentMember","id":"gid://shopify/CustomerSegmentMember/1234567890","lastOrderId":"gid://shopify/Order/1234567890"}
    {% endcapture %}

    {% assign bulkOperation = hash %}
    {% assign bulkOperation["objects"] = jsonl_string | parse_jsonl %}
  {% endif %}

  {% assign customers = bulkOperation.objects | where: "__typename", "CustomerSegmentMember" %}

  {% for customer in customers %}
    {% comment %}
      -- get additional data from this customer's last order
    {% endcomment %}

    {% capture query %}
      query {
        order(id: {{ customer.lastOrderId | json }}) {
          email
          name
          processedAt
        }
      }
    {% endcapture %}

    {% assign result = query | shopify %}

    {% if event.preview %}
      {% capture result_json %}
        {
          "data": {
            "order": {
              "email": "preview@example.com",
              "name": "%PREVIEW",
              "processedAt": {{ cutoff_date | json }}
            }
          }
        }
      {% endcapture %}

      {% assign result = result_json | parse_json %}
    {% endif %}

    {% assign order = result.data.order %}
    {% assign customer_email = customer.defaultEmailAddress.emailAddress | default: order.email %}

    {% assign processed_at_s = order.processedAt | date: "%s" | times: 1 %}
    {% assign age_d = "now" | date: "%s" | times: 1 | minus: processed_at_s | divided_by: 86400 | round %}
    {% assign age_d_modulo = age_d | modulo: interval_d %}

    {% if age_d == 0 %}
      {% continue %}

    {% elsif age_d_modulo != 0 %}
      {% capture message -%}
        Order {{ order.name }} ({{ customer_email }}) was placed on {{ processed_at_s | date: "%F" }}. Next email is due in {{ interval_d | minus: age_d_modulo }} day(s).
      {%- endcapture %}

      {% log message %}

      {% continue %}

    {% else %}
      {% assign email_options = hash %}
      {% assign email_options["to"] = customer_email %}
      {% assign email_options["subject"] = email_subject | replace: "ORDER_NUMBER", order.name %}
      {% assign email_options["body"] = email_body | replace: "ORDER_NUMBER", order.name | strip | newline_to_br %}
      {% assign email_options["reply_to"] = shop.customer_email %}
      {% assign email_options["from_display_name"] = shop.name %}

      {% if test_mode %}
        {% log email_options %}
      {% else %}
        {% action "email" email_options %}
      {% endif %}
    {% endif %}
  {% endfor %}
{% endif %}