Unpublish products that have been out of stock for x days, with Mechanic.

{% comment %}
  Preferred option order:

  {{ options.number_of_days_to_wait_before_unpublishing__number_required }}
  {{ options.sales_channel_names__required_array }}
  {{ options.only_include_products_matching_this_search_query }}
  {{ options.test_mode__boolean }}
{% endcomment %}

{% comment %}
  1. Watch for updates to inventory levels.
  2. Look up the associated product, when an update comes in.
  3. If the product's total inventory is 0, record the current time in a metafield. If the
     total inventory is not 0, delete that metafield, if it exists.
  4. Scan all products, on a schedule, retrieving each product's out-of-stock time metafield.
     For products found with a total inventory of 0, with a recorded time that's at least a
     configurable distance in days from the current time, unpublish the product.
{% endcomment %}

{% assign time_format = "%FT%T%z" %}

{% if event.topic == "shopify/inventory_levels/update" %}
  {% capture query %}
    query {
      inventoryLevel(
        id: {{ inventory_level.admin_graphql_api_id | json }}
      ) {
        id
        item {
          variant {
            product {
              id
              title
              totalInventory
              metafield(
                namespace: "mechanic"
                key: "out_of_stock_at"
              ) {
                id
                value
              }
            }
          }
        }
      }
    }
  {% endcapture %}

  {% assign result = query | shopify %}

  {% if event.preview %}
    {% capture result_json %}
      {
        "data": {
          "inventoryLevel": {
            "id": "gid://shopify/InventoryLevel/1234567890?inventory_item_id=1234567890",
            "item": {
              "variant": {
                "product": {
                  "id": "gid://shopify/Product/1234567890",
                  "title": "Short sleeve t-shirt",
                  "totalInventory": 0,
                  "metafield": null
                }
              }
            }
          }
        }
      }
    {% endcapture %}

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

  {% assign product = result.data.inventoryLevel.item.variant.product %}

  {% if product.totalInventory <= 0 and product.metafield == nil %}
    {% if options.test_mode__boolean %}
      {% action "echo" %}
        {% capture message %}Product {{ product.title | json }} ({{ product.id }}) is out of stock. Its out-of-stock time should be recorded.{% endcapture %}
        {{ message | json }}
      {% endaction %}
    {% else %}
      {% action "shopify" %}
        mutation {
          productUpdate(
            input: {
              id: {{ product.id | json }}
              metafields: [
                {
                  namespace: "mechanic"
                  key: "out_of_stock_at"
                  type: "date_time"
                  value: {{ "now" | date: time_format | json }}
                }
              ]
            }
          ) {
            userErrors {
              field
              message
            }
          }
        }
      {% endaction %}
    {% endif %}
  {% elsif product.totalInventory > 0 and product.metafield != nil %}
    {% if options.test_mode__boolean %}
      {% action "echo" %}
        {% capture message %}Product {{ product.title | json }} ({{ product.id }}) is back in stock. Its out-of-stock time should be cleared.{% endcapture %}
        {{ message | json }}
      {% endaction %}
    {% else %}
      {% action "shopify" %}
        mutation {
          metafieldDelete(
            input: {
              id: {{ product.metafield.id | json }}
            }
          ) {
            userErrors {
              field
              message
            }
          }
        }
      {% endaction %}
    {% endif %}
  {% endif %}
{% elsif event.topic contains "mechanic/scheduler/" or event.topic == "mechanic/user/trigger" %}
  {% assign now_s = "now" | date: "%s" | times: 1 %}
  {% assign minimum_out_of_stock_at_distance_s = options.number_of_days_to_wait_before_unpublishing__number_required | times: 24 | times: 60 | times: 60 %}

  {% capture query %}
    query {
      publications(first: 250) {
        edges {
          node {
            id
            name
          }
        }
      }
    }
  {% endcapture %}

  {% assign result = query | shopify %}

  {% assign publications = array %}

  {% for publication_edge in result.data.publications.edges %}
    {% if options.sales_channel_names__required_array contains publication_edge.node.name %}
      {% assign publications[publications.size] = publication_edge.node %}
    {% endif %}
  {% endfor%}

  {% if event.preview %}
    {% assign publications[0] = hash %}
    {% assign publications[0]["id"] = "gid://shopify/Publication/1234567890" %}
  {% elsif publications.size != options.sales_channel_names__required_array.size %}
    {% log publications_named: options.sales_channel_names__required_array, publications_available: result.data.publications.edges,  publications_matched: publications %}
    {% error "Unable to find all named publications. Double-check your task configuration." %}
  {% endif %}

  {% assign products_query = "inventory_total:<=0" %}

  {% if options.only_include_products_matching_this_search_query != blank %}
    {% assign products_query = products_query | append: " AND (" | append: options.only_include_products_matching_this_search_query | append: ")" %}
    {% log products_query: products_query %}
  {% endif %}

  {% assign cursor = nil %}

  {% for n in (0..100) %}
    {% capture query %}
      query {
        products(
          first: 250
          query: {{ products_query | json }}
          after: {{ cursor | json }}
        ) {
          pageInfo {
            hasNextPage
          }
          edges {
            cursor
            node {
              id
              title
              totalInventory
              {% for publication in publications %}
                publishedOnPublication{{ forloop.index }}: publishedOnPublication(publicationId: {{ publication.id | json }})
              {% endfor %}
              metafield(
                namespace: "mechanic"
                key: "out_of_stock_at"
              ) {
                id
                value
              }
            }
          }
        }
      }
    {% endcapture %}

    {% assign result = query | shopify %}

    {% if event.preview %}
      {% capture result_json %}
        {
          "data": {
            "products": {
              "pageInfo": {
                "hasNextPage": false
              },
              "edges": [
                {
                  "cursor": "eyJsYXN0X2lkIjo0MzQzOTQxNDMxMzMxLCJsYXN0X3ZhbHVlIjo0MzQzOTQxNDMxMzMxfQ==",
                  "node": {
                    "id": "gid://shopify/Product/1234567890",
                    "title": "Short sleeve t-shirt",
                    "totalInventory": 0,
                    {% for publication in publications %}
                      {{ "publishedOnPublication" | append: forloop.index | json }}: true,
                    {% endfor %}
                    "metafield": {
                      "value": {{ now_s | minus: minimum_out_of_stock_at_distance_s | minus: 1 | append: "" | json }}
                    }
                  }
                }
              ]
            }
          }
        }
      {% endcapture %}

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

    {% for product_edge in result.data.products.edges %}
      {% assign product = product_edge.node %}

      {% if product.metafield == nil %}
        {% log %}
          {% capture message %}Product {{ product.id }} is out of stock, but its out-of-stock time was not recorded. This product will not be unpublished now, but its out-of-stock time will be set to the current time.{% endcapture %}
          {{ message | json }}
        {% endlog %}

        {% unless options.test_mode__boolean %}
          {% action "shopify" %}
            mutation {
              productUpdate(
                input: {
                  id: {{ product.id | json }}
                  metafields: [
                    {
                      namespace: "mechanic"
                      key: "out_of_stock_at"
                      type: "date_time"
                      value: {{ "now" | date: time_format | json }}
                    }
                  ]
                }
              ) {
                userErrors {
                  field
                  message
                }
              }
            }
          {% endaction %}
        {% endunless %}

        {% continue %}
      {% endif %}

      {% assign out_of_stock_at_s = product.metafield.value | date: "%s" | times: 1 %}
      {% assign out_of_stock_at_distance_s = now_s | minus: out_of_stock_at_s %}

      {% assign unpublishings = array %}

      {% for publication in publications %}
        {% assign key = "publishedOnPublication" | append: forloop.index %}
        {% if product[key] %}
          {% assign unpublishing = array %}
          {% assign unpublishing[0] = product.id %}
          {% assign unpublishing[1] = publication.id %}
          {% assign unpublishings[unpublishings.size] = unpublishing %}
        {% endif %}
      {% endfor %}

      {% if unpublishings == empty %}
        {% log %}
          {% capture message %}Product {{ product.title | json }} ({{ product.id }}) has been out of stock for {{ out_of_stock_at_distance_s | divided_by: 60 | divided_by: 60 | divided_by: 24 | round: 2 }} day(s), but is not published - nothing to do.{% endcapture %}
          {{ message | json }}
        {% endlog %}
        {% continue %}
      {% endif %}

      {% if out_of_stock_at_distance_s < minimum_out_of_stock_at_distance_s %}
        {% log %}
          {% capture message %}Product {{ product.title | json }} ({{ product.id }}) is out of stock, and is published, but has only been out of stock for {{ out_of_stock_at_distance_s | divided_by: 60 | divided_by: 60 | divided_by: 24 | round: 2 }} day(s).{% endcapture %}
          {{ message | json }}
        {% endlog %}
        {% continue %}
      {% endif %}

      {% if options.test_mode__boolean %}
        {% action "echo" %}
          {% capture message %}Product {{ product.title | json }} ({{ product.id }}) is out of stock, and has been out of stock for {{ out_of_stock_at_distance_s | divided_by: 60 | divided_by: 60 | divided_by: 24 | round: 2 }} day(s). It should be unpublished.{% endcapture %}
          {{ message | json }}
        {% endaction %}
      {% else %}
        {% action "shopify" %}
          mutation {
            {% for unpublishing in unpublishings %}
              publishableUnpublish{{ forloop.index }}: publishableUnpublish(
                id: {{ unpublishing[0] | json }}
                input: {
                  publicationId: {{ unpublishing[1] | json }}
                }
              ) {
                userErrors {
                  field
                  message
                }
              }
            {% endfor %}
          }
        {% endaction %}
      {% endif %}
    {% endfor %}

    {% if result.data.products.pageInfo.hasNextPage %}
      {% assign cursor = result.data.products.edges.last.cursor %}
    {% else %}
      {% break %}
    {% endif %}
  {% endfor %}
{% endif %}