class SubscriptionVariantsService
  # Includes the following variants:
  # - Variants of permitted producers
  # - Variants of hub
  # - Variants that are in outgoing exchanges where the hub is receiver
  def self.eligible_variants(distributor)
    variant_conditions = ["spree_products.supplier_id IN (?)", permitted_producer_ids(distributor)]
    exchange_variant_ids = outgoing_exchange_variant_ids(distributor)
    if exchange_variant_ids.present?
      variant_conditions[0] << " OR spree_variants.id IN (?)"
      variant_conditions << exchange_variant_ids
    end

    Spree::Variant.joins(:product).where(is_master: false).where(*variant_conditions)
  end

  def self.in_open_and_upcoming_order_cycles?(distributor, schedule, variant)
    scope = ExchangeVariant.joins(exchange: { order_cycle: :schedules })
      .where(variant_id: variant, exchanges: { incoming: false, receiver_id: distributor })
      .merge(OrderCycle.not_closed)
    scope = scope.where(schedules: { id: schedule })
    scope.any?
  end

  def self.permitted_producer_ids(distributor)
    other_permitted_producer_ids = EnterpriseRelationship.joins(:parent)
      .permitting(distributor.id).with_permission(:add_to_order_cycle)
      .merge(Enterprise.is_primary_producer)
      .pluck(:parent_id)

    other_permitted_producer_ids | [distributor.id]
  end

  def self.outgoing_exchange_variant_ids(distributor)
    ExchangeVariant.select("DISTINCT exchange_variants.variant_id").joins(:exchange)
      .where(exchanges: { incoming: false, receiver_id: distributor.id })
      .pluck(:variant_id)
  end
end