def export
  Product.find_by_sql subset.
    join(products).on(products[:id].eq order_items[:product_id]).
    project(products[Arel.star])
end

def subset
  order_items.
    join(colors).on(colors[:id].eq order_items[:color_id]).
    join(orders).on(orders[:id].eq order_items[:order_id]).
    join(addresses).on(addresses[:id].eq orders[:address_id]).
    group(order_items[:product_id]).
    having(order_items[:id].count.gteq 3).
    where(red_colored.and during_this_month)
end

def products
  Product.arel_table
end

def order_items
  OrderItem.arel_table
end

def orders
  Order.arel_table
end

def colors
  Color.arel_table
end

def addresses
  Address.arel_table
end

def red_colored
  colors[:code].eq 'red'
end

def during_this_month
  orders[:created_at].gteq Time.now.beginning_of_month
end