spree-contrib/spree-product-assembly

module Spree::ShipmentDecorator
  # Overriden from Spree core as a product bundle part should not be put
  # together with an individual product purchased (even though they're the
  # very same variant) That is so we can tell the store admin which units
  # were purchased individually and which ones as parts of the bundle
  #
  # Account for situations where we can't track the line_item for a variant.
  # This should avoid exceptions when users upgrade from spree 1.3
  #
  # TODO Can possibly be removed as well. We already override the manifest
  # partial so we can get the product there
  ManifestItem = Struct.new(:part, :product, :line_item, :variant, :quantity, :states)

  def manifest
    inventory_units.group_by(&:variant_id).map do |variant, inventory_units|
      inventory_units.group_by(&:line_item_id).map do |line_item, units|

        line_item = units.first.line_item
        variant = units.first.variant

        if Gem.loaded_specs['spree_core'].version >= Gem::Version.create('3.3.0')
          states = units.group_by(&:state).each_with_object({}) { |(state, iu), acc| acc[state] = iu.sum(&:quantity) }
          quantity = units.sum(&:quantity)
        else
          states = units.group_by(&:state).each_with_object({}) { |(state, iu), acc| acc[state] = iu.count }
          quantity = units.length
        end

        part = line_item.try(:product).try(:assembly?) || false
        ManifestItem.new(part,
                          line_item.try(:product),
                          line_item,
                          variant,
                          quantity,
                          states)
      end
    end.flatten
  end

  # There might be scenarios where we don't want to display every single
  # variant on the shipment. e.g. when ordering a product bundle that includes
  # 5 other parts. Frontend users should only see the product bundle as a
  # single item to ship
  def line_item_manifest
    inventory_units.includes(:line_item, :variant).group_by(&:line_item).map do |line_item, units|
      states = {}
      units.group_by(&:state).each { |state, iu| states[state] = iu.count }
      OpenStruct.new(line_item: line_item, variant: line_item.variant, quantity: units.length, states: states)
    end
  end

  def inventory_units_for_item(line_item, variant)
    inventory_units.where(line_item_id: line_item.id, variant_id: variant.id)
  end
end

Spree::Shipment.prepend Spree::ShipmentDecorator