require 'parallel'

module Spree
  module SpreeChannable
    module ProductDecorator
      def self.prepended(base)
        class << base

          def to_channable_variant_xml(products)
            builder = Nokogiri::XML::Builder.new do |xml|
              xml.feed(xmlns: 'http://www.w3.org/2005/Atom') do
                xml.title 'Channable variant feed'
                xml.link(rel: 'self', href: ::SpreeChannable.configuration.host)
                xml.updated DateTime.now.strftime('%Y-%m-%dT%H:%M:%S%z')

                Parallel.map(products) {|product| product.to_channable_variant_xml}.each do |products_xml|
                  products_xml.each do |variant_xml|
                    xml.parent << Nokogiri::XML(variant_xml).at('product')
                  end
                end

              end
            end

            builder.to_xml
          end

          def to_channable_product_xml(products)
            builder = Nokogiri::XML::Builder.new do |xml|
              xml.feed(xmlns: 'http://www.w3.org/2005/Atom') do
                xml.title 'Channable product feed'
                xml.link(rel: 'self', href: ::SpreeChannable.configuration.host)
                xml.updated DateTime.now.strftime('%Y-%m-%dT%H:%M:%S%z')

                xml.products do
                  Parallel.map(products) {|product| product.to_channable_product_xml}.each do |product_xml|
                    xml.parent << Nokogiri::XML(product_xml).at('product')
                  end
                end

              end
            end

            builder.to_xml
          end
        end
      end


      def to_channable_variant_xml
        variants.active.map do |variant|
          variant.to_channable_feed_entry
        end
      end

      def to_channable_product_xml
        Nokogiri::XML::Builder.new do |xml|
          xml.product do
            xml.id id
            xml.title "#{name}"
            xml.description ActionController::Base.helpers.strip_tags(normalized_description)
            xml.link URI.join(::SpreeChannable.configuration.host, "/#{::SpreeChannable.configuration.url_prefix}/" + slug).to_s
            (xml.image_link URI.join(::SpreeChannable.configuration.image_host, images.first.attachment.url(:large)).to_s) if images.any?
            xml.condition property('product_condition') || ::SpreeChannable.configuration.product_condition

            xml.price price

            xml.brand property('brand') || ::SpreeChannable.configuration.brand

            xml.categories do
              taxons.each do |taxon|
                xml.category taxon.self_and_ancestors.collect(&:name).join('|')
              end
            end

            xml.currency Spree::Config.currency
            xml.locale I18n.default_locale

            # Property fields

            xml.gender property('gender') || 'Not set'
            xml.delivery_period property('delivery_period') || ::SpreeChannable.configuration.delivery_period
            xml.material property('material') || 'Not set'

            xml.variants do
              variants.each do |variant|
                xml.variant do
                  xml.id variant.id
                  xml.product_id id
                  xml.options_text variant.options_text
                  (xml.image_link URI.join(::SpreeChannable.configuration.image_host, variant.get_images.first.attachment.url(:large)).to_s) unless variant.get_images.empty?

                  xml.availability variant.can_supply?
                  xml.stock variant.total_on_hand
                  xml.price variant.price
                  xml.sale_price variant.respond_to?(:sale_price) ? (variant.sale_price || variant.price) : variant.price

                  xml.sku variant.sku

                  xml.currency Spree::Config.currency
                  xml.locale I18n.default_locale

                  variant.option_values.each do |option_value|
                    xml.send(option_value.option_type.name, option_value.presentation)
                  end
                end
              end
            end

          end
        end.to_xml
      end

    end
  end
end

Spree::Product.prepend(Spree::SpreeChannable::ProductDecorator)