Percent of a subset (by vendor list), with min/max caps

{% liquid
  # Shipping is a percentage of ONLY items from a chosen vendor list.
  # Example: charge 8% of all ACME/Contoso items, capped between $3–$20.

  # --- editable settings ---
  assign service_name = "Vendor Subset Shipping"
  assign service_code = "VENDOR_SUBSET"
  assign currency = "USD"
  assign description = "Calculated on selected vendors only"
  assign shipping_percentage = 8                # percent of subset subtotal
  assign vendors_raw = "ACME|Contoso"           # pipe-separated list, exact vendor names
  assign min_price = 300                        # cents
  assign max_price = 2000                       # cents

  # --- logic ---
  assign vendors = vendors_raw | split: "|"     # array of vendor names
  assign subset_total = 0

  for item in shopify_rate_check.items
    if vendors contains item.vendor
      assign line_price = item.price | times: item.quantity
      assign subset_total = subset_total | plus: line_price
    endif
  endfor

  assign shipping_price = subset_total | times: shipping_percentage | divided_by: 100
  assign shipping_price = shipping_price | at_least: min_price | at_most: max_price

  assign rate = rate | merge: "currency", currency
  assign rate = rate | merge: "service_name", service_name
  assign rate = rate | merge: "service_code", service_code
  assign rate = rate | merge: "total_price", shipping_price
  assign rate = rate | merge: "description", description

  assign rates = rates | array_append: rate
%}
{
  "rates": {{ rates | array_wrap | json }}
}