module ActiveMerchant
  module Shipping
    class Carrier
      
      include RequiresParameters
      include PostsData
      include Quantified
      
      attr_reader :last_request
      attr_accessor :test_mode
      alias_method :test_mode?, :test_mode
      
      # Credentials should be in options hash under keys :login, :password and/or :key.
      def initialize(options = {})
        requirements.each {|key| requires!(options, key)}
        @options = options
        @last_request = nil
        @test_mode = @options[:test]
      end

      # Override to return required keys in options hash for initialize method.
      def requirements
        []
      end
      
      # Override with whatever you need to get the rates
      def find_rates(origin, destination, packages, options = {})
      end
      
      # Validate credentials with a call to the API. By default this just does a find_rates call
      # with the orgin and destination both as the carrier's default_location. Override to provide
      # alternate functionality, such as checking for test_mode to use test servers, etc.
      def valid_credentials?
        location = self.class.default_location
        find_rates(location,location,Package.new(100, [5,15,30]), :test => test_mode)
      rescue ActiveMerchant::Shipping::ResponseError
        false
      else
        true
      end
      
      def maximum_weight
        Mass.new(150, :pounds)
      end
      
      protected
      
      def node_text_or_nil(xml_node)
        xml_node ? xml_node.text : nil
      end
      
      # Override in subclasses for non-U.S.-based carriers.
      def self.default_location
        Location.new( :country => 'US',
                      :state => 'CA',
                      :city => 'Beverly Hills',
                      :address1 => '455 N. Rexford Dr.',
                      :address2 => '3rd Floor',
                      :zip => '90210',
                      :phone => '1-310-285-1013',
                      :fax => '1-310-275-8159')
      end
      
      # Use after building the request to save for later inspection. Probably won't ever be overridden.
      def save_request(r)
        @last_request = r
      end
    end
  end
end