module Nexpose
  # This class represents each of the /NexposeReport[@version='1.0']/nodes/node/endpoints/endpoint/services/service
  # elements in the Nexpose Full XML document.
  #
  # It provides a convenient way to access the information scattered all over
  # the XML in attributes and nested tags.
  #
  # Instead of providing separate methods for each supported property we rely
  # on Ruby's #method_missing to do most of the work.
  class Service
    # Accepts an XML node from Nokogiri::XML.
    def initialize(xml_node)
      @xml = xml_node
    end

    # List of supported tags. They can be attributes, simple descendans or
    # collections (e.g. <references/>, <tags/>)
    def supported_tags
      [
        # attributes
        :name,

        # simple tags

        # multiple tags
        :fingerprints, :configurations, :tests
      ]
    end

    # Convert each ./test/test entry into a simple hash
    def tests(*args)
      @xml.xpath('./tests/test').collect do |xml_test|
        content = if xml_test.at_xpath('./Paragraph')
                    xml_test.at_xpath('./Paragraph').text.split("\n").collect(&:strip).reject{|line| line.empty?}.join("\n")
                  else
                    'n/a'
                  end
        {
               id: xml_test.attributes['id'],
           status: xml_test.attributes['status'],
          content: content
        }
      end
    end


    # This allows external callers (and specs) to check for implemented
    # properties
    def respond_to?(method, include_private=false)
      return true if supported_tags.include?(method.to_sym)
      super
    end

    # This method is invoked by Ruby when a method that is not defined in this
    # instance is called.
    #
    # In our case we inspect the @method@ parameter and try to find the
    # attribute, simple descendent or collection that it maps to in the XML
    # tree.
    def method_missing(method, *args)

      # We could remove this check and return nil for any non-recognized tag.
      # The problem would be that it would make tricky to debug problems with
      # typos. For instance: <>.potr would return nil instead of raising an
      # exception
      unless supported_tags.include?(method)
        super
        return
      end

      # First we try the attributes. In Ruby we use snake_case, but in XML
      # CamelCase is used for some attributes
      translations_table = {
      }

      method_name = translations_table.fetch(method, method.to_s)
      return @xml.attributes[method_name].value if @xml.attributes.key?(method_name)

      # Finally the enumerations: references, tags
      if ['fingerprints', 'configurations'].include?(method_name)
        xpath_selector = {
          'fingerprints' => './fingerprints/fingerprint',
          'configurations' => './configuration/config'
        }[method_name]

        @xml.xpath(xpath_selector).collect do |xml_item|
          {:text => xml_item.text}.merge(
            Hash[
              xml_item.attributes.collect do |name, xml_attribute|
                [name.sub(/-/,'_').to_sym, xml_attribute.value]
              end
            ]
          )
        end
      else
        # nothing found, the tag is valid but not present in this ReportItem
        return nil
      end
    end
  end
end