script.liquid

{% assign product_tags = options.product_tags_to_monitor__array %}
{% assign product_types = options.product_types_to_monitor__array %}
{% assign only_sync_active_products = options.only_sync_active_products__boolean %}

{% assign primary_location = shop.locations[shop.primary_location_id] %}

{% if product_tags == blank and product_types == blank %}
  {% error "You must choose to monitor products either by tags or types." %}
{% elsif product_tags != blank and product_types != blank %}
  {% error "Choose to monitor products either by tags or types, but not both." %}
{% endif %}

{% if event.topic == "mechanic/user/trigger" or event.topic contains "mechanic/scheduler/" %}
  {% comment %}
    -- run query for all variants matched by product tags or types
  {% endcomment %}

  {% assign variants_by_product = hash %}
  {% assign cursor = nil %}
  {% assign search_query_parts = array %}

  {% for product_type in product_types %}
    {% assign search_query_parts[search_query_parts.size] = product_type | json | prepend: "product_type:" %}
  {% endfor %}

  {% for product_tag in product_tags %}
    {% assign search_query_parts[search_query_parts.size] = product_tag | json | prepend: "tag:" %}
  {% endfor %}

  {% capture search_query -%}
    location_id:{{ shop.primary_location_id }} ({{ search_query_parts | join: " OR " }}) managed:true
  {%- endcapture %}

  {% if only_sync_active_products %}
    {% assign search_query = search_query | append: " product_status:active" %}
  {% endif %}

  {% for n in (0..200) %}
    {% capture query %}
      query {
        productVariants(
          first: 150
          query: {{ search_query | json }}
          after: {{ cursor | json }}
        ) {
          pageInfo {
            hasNextPage
            endCursor
          }
          nodes {
            id
            inventoryItem {
              id
              inventoryLevel(locationId: {{ primary_location.admin_graphql_api_id | json }}) {
                quantities(names: "available") {
                  name
                  quantity
                }
              }
            }
            product {
              id
            }
          }
        }
      }
    {% endcapture %}

    {% assign result = query | shopify %}

    {% if event.preview %}
      {% capture result_json %}
        {
          "data": {
            "productVariants": {
              "nodes": [
                {
                  "id": "gid://shopify/ProductVariant/1234567890",
                  "inventoryItem": {
                    "id": "gid://shopify/InventoryItem/1234567890",
                    "inventoryLevel": {
                      "quantities": [
                        {
                          "name": "available",
                          "quantity": 30
                        }
                      ]
                    }
                  },
                  "product": {
                    "id": "gid://shopify/Product/1234567890"
                  }
                },
                {
                  "id": "gid://shopify/ProductVariant/2345678901",
                  "inventoryItem": {
                    "id": "gid://shopify/InventoryItem/2345678901",
                    "inventoryLevel": {
                      "quantities": [
                        {
                          "name": "available",
                          "quantity": {% if event.topic == "mechanic/user/trigger" %}30{% else %}31{% endif %}
                        }
                      ]
                    }
                  },
                  "product": {
                    "id": "gid://shopify/Product/1234567890"
                  }
                }
              ]
            }
          }
        }
      {% endcapture %}

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

    {% for variant in result.data.productVariants.nodes %}
      {% assign variants_by_product[variant.product.id]
        = variants_by_product[variant.product.id]
        | default: array
        | push: variant
      %}
    {% endfor %}

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

  {% if variants_by_product == blank %}
    {% error
      message: "No matching product variants found! Check your product tag or type settings for this task.",
      search_query: search_query
    %}
    {% break %}
  {% endif %}

{% elsif event.topic == "user/sync_variant_inventory/set_cache" %}
  {% comment %}
    -- this user event is called from the scheduler event, to process any products without a cache entry
  {% endcomment %}

  {% if event.data.products_missing_cache == blank %}
    {% error "No products with missing cache were passed to this event." %}
  {% endif %}

  {% assign variants_by_product = event.data.products_missing_cache %}
{% endif %}

{% if event.topic == "mechanic/user/trigger" or event.topic == "user/sync_variant_inventory/set_cache" %}
  {% comment %}
    -- this event is run manually for initial setup, but will also be triggered via a custom event to handle any products that don't yet have a cache setting (typically new products, but can be existing ones if their cache expires or if the task configuration is changed)
  {% endcomment %}

  {% assign products_out_of_sync = array %}

  {% for pair in variants_by_product %}
    {% assign product_id = pair[0] %}
    {% assign variants = pair[1] %}

    {% assign available_quantites = array %}

    {% for variant in variants %}
      {% assign available_quantites = available_quantites | push: variant.inventoryItem.inventoryLevel.quantities.first.quantity %}
    {% endfor %}

    {% assign inventory_total = available_quantites | sum %}
    {% assign expected_inventory_total = available_quantites.first | times: available_quantites.size %}

    {% if inventory_total != expected_inventory_total %}
      {% assign product_out_of_sync = hash %}
      {% assign product_out_of_sync["product_id"] = product_id %}
      {% assign product_out_of_sync["expected_inventory_total"] = expected_inventory_total %}
      {% assign product_out_of_sync["current_inventory_total"] = inventory_total %}
      {% assign product_out_of_sync["available_quantites"] = available_quantites %}
      {% assign products_out_of_sync = products_out_of_sync | push: product_out_of_sync %}

    {% else %}
      {% assign cache_key = "inventory_by_product:" | append: product_id %}
      {% action "cache", "set", cache_key, available_quantites.first %}
    {% endif %}
  {% endfor %}

  {% if products_out_of_sync != blank %}
    {% action "echo"
      __error: "Variant inventory levels are not in sync for these products. Manually ensure everything is at the same level so they may be managed by this task.",
      products_out_of_sync: products_out_of_sync
    %}
  {% endif %}

{% elsif event.topic contains "mechanic/scheduler/" %}
  {% assign inventory_adjustments = array %}
  {% assign products_missing_cache = hash %}

  {% for pair in variants_by_product %}
    {% assign product_id = pair[0] %}
    {% assign variants = pair[1] %}

    {% assign cache_key = "inventory_by_product:" | append: product_id %}
    {% assign inventory_old = cache[cache_key] %}

    {% if event.preview %}
      {% assign inventory_old = 30 %}
    {% endif %}

    {% if inventory_old == blank %}
      {% comment %}
        -- if no cache has been set for this product yet, then save it for later processing and move to next product
      {% endcomment %}

      {% assign products_missing_cache[product_id] = variants %}
      {% continue %}
    {% endif %}

    {% assign available_quantites = array %}

    {% for variant in variants %}
      {% assign available_quantites = available_quantites | push: variant.inventoryItem.inventoryLevel.quantities.first.quantity %}
    {% endfor %}

    {% assign inventory_total_old = inventory_old | times: available_quantites.size %}
    {% assign inventory_total_new = available_quantites | sum %}
    {% assign inventory_total_diff = inventory_total_new | minus: inventory_total_old %}
    {% assign inventory_new = inventory_old | plus: inventory_total_diff %}

    {% if inventory_new == inventory_old %}
      {% log
        message: "No inventory adjustments needed for this product.",
        product_id: product_id
      %}
      {% continue %}
    {% endif %}

    {% log
      message: "Adjusting inventory for this product.",
      inventory_old: inventory_old,
      inventory_total_old: inventory_total_old,
      inventory_total_new: inventory_total_new,
      inventory_total_diff: inventory_total_diff,
      inventory_new: inventory_new,
      product_id: product_id,
      variants_count: variants.size
    %}

    {% action "cache", "set", cache_key, inventory_new %}

    {% for variant in variants %}
      {% assign inventory_adjustment = hash %}
      {% assign inventory_adjustment["inventoryItemId"] = variant.inventoryItem.id %}
      {% assign inventory_adjustment["locationId"] = primary_location.admin_graphql_api_id %}
      {% assign inventory_adjustment["delta"] = inventory_new | minus: variant.inventoryItem.inventoryLevel.quantities.first.quantity %}
      {% assign inventory_adjustments = inventory_adjustments | push: inventory_adjustment %}
    {% endfor %}
  {% endfor %}

  {% if inventory_adjustments != blank %}
    {% assign groups_of_inventory_adjustments = inventory_adjustments | in_groups_of: 250, fill_with: false %}

    {% for group_of_inventory_adjustments in groups_of_inventory_adjustments %}
      {% action "shopify" %}
        mutation {
          inventoryAdjustQuantities(
            input: {
              reason: "correction"
              name: "available"
              changes: {{ group_of_inventory_adjustments | graphql_arguments }}
            }
          ) {
            inventoryAdjustmentGroup {
              reason
              changes {
                name
                delta
                quantityAfterChange
                item {
                  id
                  sku
                }
                location {
                  name
                }
              }
            }
            userErrors {
              code
              field
              message
            }
          }
        }
      {% endaction %}
    {% endfor %}
  {% endif %}

  {% if products_missing_cache != blank %}
    {% assign product_ids = products_missing_cache | keys %}

    {% log
      message: "Found these products without cache entries. Sending them to custom event to set caches if possible.",
      product_ids: product_ids
    %}

    {% action "event" %}
      {
        "topic": "user/sync_variant_inventory/set_cache",
        "task_id": {{ task.id | json }},
        "data": {
          "products_missing_cache": {{ products_missing_cache | json }}
        }
      }
    {% endaction %}
  {% endif %}
{% endif %}