require 'cgi'
require 'builder'

module ActiveMerchant
  module Shipping
    class Shipwire < Carrier
      self.retry_safe = true
      
      cattr_reader :name
      @@name = "Shipwire"
      
      URL = 'https://api.shipwire.com/exec/RateServices.php'
      SCHEMA_URL = 'http://www.shipwire.com/exec/download/RateRequest.dtd'      
      WAREHOUSES = { 'CHI' => 'Chicago',
                     'LAX' => 'Los Angeles',
                     'REN' => 'Reno',
                     'VAN' => 'Vancouver',
                     'TOR' => 'Toronto',
                     'UK'  => 'United Kingdom'
                   }
                   
      CARRIERS = [ "UPS", "USPS", "FedEx", "Royal Mail", "Parcelforce", "Pharos", "Eurotrux", "Canada Post", "DHL" ]
                   
      SUCCESS = "OK"
      SUCCESS_MESSAGE = "Successfully received the shipping rates"
      NO_RATES_MESSAGE = "No shipping rates could be found for the destination address"
      REQUIRED_OPTIONS = [:login, :password].freeze
      
      def find_rates(origin, destination, packages, options = {})
        requires!(options, :items)
        commit(origin, destination, options)
      end
      
      def valid_credentials?
        location = self.class.default_location
        find_rates(location, location, Package.new(100, [5,15,30]),
          :items => [ { :sku => '', :quantity => 1 } ]
        )
      rescue ActiveMerchant::Shipping::ResponseError
        true
      rescue ActiveMerchant::ResponseError => e
        e.response.code != '401'
      end
      
      private
      def requirements
        REQUIRED_OPTIONS
      end
      
      def build_request(destination, options)
        xml = Builder::XmlMarkup.new
        xml.instruct!
        xml.declare! :DOCTYPE, :RateRequest, :SYSTEM, SCHEMA_URL
        xml.tag! 'RateRequest' do
          add_credentials(xml)
          add_order(xml, destination, options) 
        end
        xml.target!
      end
      
      def add_credentials(xml)
        xml.tag! 'EmailAddress', @options[:login]
        xml.tag! 'Password', @options[:password]
      end

      def add_order(xml, destination, options)
        xml.tag! 'Order', :id => options[:order_id] do
          xml.tag! 'Warehouse', options[:warehouse] || '00'

          add_address(xml, destination)
          Array(options[:items]).each_with_index do |line_item, index|
            add_item(xml, line_item, index)
          end
        end
      end

      def add_address(xml, destination)
        xml.tag! 'AddressInfo', :type => 'Ship' do
          if destination.name.present?
            xml.tag! 'Name' do
              xml.tag! 'Full', destination.name
            end
          end
          xml.tag! 'Address1', destination.address1
          xml.tag! 'Address2', destination.address2 unless destination.address2.blank?
          xml.tag! 'Address3', destination.address3 unless destination.address3.blank?
          xml.tag! 'Company', destination.company unless destination.company.blank?
          xml.tag! 'City', destination.city
          xml.tag! 'State', destination.state unless destination.state.blank?
          xml.tag! 'Country', destination.country_code
          xml.tag! 'Zip', destination.zip  unless destination.zip.blank?
        end
      end
      
     # Code is limited to 12 characters
      def add_item(xml, item, index)
        xml.tag! 'Item', :num => index do
          xml.tag! 'Code', item[:sku]
          xml.tag! 'Quantity', item[:quantity]
        end
      end

      def commit(origin, destination, options)
        request = build_request(destination, options)
        save_request(request)
        
        response = parse( ssl_post(URL, "RateRequestXML=#{CGI.escape(request)}") )
        
        RateResponse.new(response["success"], response["message"], response, 
          :xml     => response,
          :rates   => build_rate_estimates(response, origin, destination),
          :request => last_request
        )
      end
      
      def build_rate_estimates(response, origin, destination)
        response["rates"].collect do |quote|
          RateEstimate.new(origin, destination, carrier_for(quote["service"]), quote["service"],
            :service_code    => quote["method"],
            :total_price     => quote["cost"],
            :currency        => quote["currency"],
            :delivery_range  => [ timestamp_from_business_day(quote["delivery_min"]),
                                  timestamp_from_business_day(quote["delivery_max"]) ]
          )
        end
      end
      
      def carrier_for(service)
        CARRIERS.dup.find{ |carrier| service.to_s =~ /^#{carrier}/i } || service.to_s.split(" ").first
      end

      def parse(xml)
        response = {}
        response["rates"] = []

        document = REXML::Document.new(xml)
    
        response["status"] = parse_child_text(document.root, "Status")
             
        document.root.elements.each("Order/Quotes/Quote") do |e|
          rate = {}
          rate["method"]    = e.attributes["method"]
          rate["warehouse"] = parse_child_text(e, "Warehouse")
          rate["service"]   = parse_child_text(e, "Service")
          rate["cost"]      = parse_child_text(e, "Cost")
          rate["currency"]  = parse_child_attribute(e, "Cost", "currency")
          if delivery_estimate = e.elements["DeliveryEstimate"]
            rate["delivery_min"]  = parse_child_text(delivery_estimate, "Minimum").to_i
            rate["delivery_max"]  = parse_child_text(delivery_estimate, "Maximum").to_i
          end
          response["rates"] << rate
        end

        if response["status"] == SUCCESS && response["rates"].any?
          response["success"] = true
          response["message"] = SUCCESS_MESSAGE
        elsif response["status"] == SUCCESS && response["rates"].empty?
          response["success"] = false
          response["message"] = NO_RATES_MESSAGE
        else
          response["success"] = false
          response["message"] = parse_child_text(document.root, "ErrorMessage")
        end
        
        response
      rescue NoMethodError => e
        raise ActiveMerchant::Shipping::ResponseContentError.new(e, xml)
      end
      
      def parse_child_text(parent, name)
        if element = parent.elements[name]
          element.text
        end
      end
      
      def parse_child_attribute(parent, name, attribute)
        if element = parent.elements[name]
          element.attributes[attribute]
        end
      end
    end
  end
end