Auto-price products based on their compare-at prices, with Mechanic.

{% if options.run_automatically_for_product_updates__boolean %}
  shopify/products/update
{% endif %}
{% if options.run_daily__boolean %}
  mechanic/scheduler/daily
{% endif %}
mechanic/user/trigger

{% assign multiplier_when_calculating_price = options.multiplier_when_calculating_price__number_required %}
{% assign product_tag_to_monitor = options.product_tag_to_monitor %}
{% assign only_process_active_products = options.only_process_active_products__boolean %}
{% assign run_automatically_for_product_updates = options.run_automatically_for_product_updates__boolean %}
{% assign run_daily = options.run_daily__boolean %}
{% assign test_mode = options.test_mode__boolean %}

{% if multiplier_when_calculating_price < 0 %}
  {% error "Price multiplier must be at least 0. :)" %}
{% endif %}

{% assign search_query = nil %}

{% if only_process_active_products %}
  {% assign search_query = "product_status:active" %}
{% endif %}

{% if product_tag_to_monitor != blank %}
  {%- capture search_query -%}
    {{ search_query }} tag:{{ product_tag_to_monitor | json }}
  {%- endcapture -%}
{% endif %}

{% comment %}
  -- for product create/update filter the variants query with the product ID that caused the event
{% endcomment %}

{% if event.topic == "shopify/products/update" %}
  {%- capture search_query -%}
    product_id:{{ product.id }} {{ search_query }}
  {%- endcapture -%}
{% endif %}

{% unless event.preview %}
  {% log search_query: search_query %}
{% endunless %}

{% comment %}
  -- querying variants resource to support 2K variants per product without two concurrent pagination loops
{% endcomment %}

{% assign summaries = array %}
{% assign variant_inputs_by_product = hash %}

{% assign cursor = nil %}

{% for n in (0..200) %}
  {% capture query %}
    query {
      productVariants(
        first: 250
        after: {{ cursor | json }}
        query: {{ search_query | json }}
      ) {
        pageInfo {
          hasNextPage
          endCursor
        }
        nodes {
          id
          displayName
          sku
          price
          compareAtPrice
          product {
            id
          }
        }
      }
    }
  {% endcapture %}

  {% assign result = query | shopify %}

  {% if event.preview %}
    {% capture result_json %}
      {
        "data": {
          "productVariants": {
            "nodes": [
              {
                "id": "gid://shopify/ProductVariant/1234567890",
                "displayName": "Widget",
                "sku": "WDGT",
                "price": "99.00",
                "compareAtPrice": "10.00",
                "product": {
                  "id": "gid://shopify/Product/1234567890"
                }
              }
            ]
          }
        }
      }
    {% endcapture %}

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

  {% comment %}
    -- process this batch of variants to see which qualify to have their price updated
  {% endcomment %}

  {% for variant in result.data.productVariants.nodes %}
    {% if variant.compareAtPrice == blank %}
      {% continue %}
    {% endif %}

    {% assign compare_at_price = variant.compareAtPrice | times: 1 %}
    {% assign price = variant.price | times: 1 %}
    {% assign desired_price
      = compare_at_price
      | times: multiplier_when_calculating_price
      | round: 2
    %}

    {% if desired_price != price %}
      {% if test_mode %}
        {% assign summary = hash %}
        {% assign summary["id"] = variant.id %}
        {% assign summary["displayName"] = variant.displayName | remove: " - Default Title" %}
        {% assign summary["sku"] = variant.sku %}
        {% assign summary["compare_at_price"] = compare_at_price %}
        {% assign summary["current_price"] = price %}
        {% assign summary["desired_price"] = desired_price %}
        {% assign summaries = summaries | push: summary %}

      {% else %}
        {% assign variant_input = hash %}
        {% assign variant_input["id"] = variant.id %}
        {% assign variant_input["price"] = desired_price | append: "" %}
        {% assign variant_inputs_by_product[variant.product.id]
          = variant_inputs_by_product[variant.product.id]
          | default: array
          | push: variant_input
        %}
      {% endif %}
    {% endif %}
  {% endfor %}

  {% if result.data.productVariants.pageInfo.hasNextPage %}
    {% assign cursor = result.data.productVariants.pageInfo.endCursor %}
  {% else %}
    {% break %}
  {% endif %}
{% endfor %}

{% for keyval in variant_inputs_by_product %}
  {% action "shopify" %}
    mutation {
      productVariantsBulkUpdate(
        productId: {{ keyval[0] | json }}
        variants: {{ keyval[1] | graphql_arguments }}
      ) {
        userErrors {
          code
          field
          message
        }
      }
    }
  {% endaction %}

{% else %}
  {% log "No variants qualified to be updated on this task run." %}
{% endfor %}

{% if summaries != blank %}
  {% log
    test_mode: test_mode,
    variants_to_be_updated: summaries
  %}
{% endif %}