%w(rubygems hpricot).each do |gem|
  require gem
end

# == ApricotEatsGorilla
# 
# Apricot eats Gorilla is a SOAP communication helper. It translates between
# SOAP messages (XML) and Ruby Hashes and comes with some additional helpers
# for working with SOAP services.
class ApricotEatsGorilla
  class << self

    # Flag to enable sorting of Hash keys.
    attr_accessor :sort_keys

    # Flag to disable conversion of XML tags to lowerCamelCase.
    attr_accessor :disable_tag_names_to_lower_camel_case

    # Flag to disable conversion of Hash keys to snake_case.
    attr_accessor :disable_hash_keys_to_snake_case

    # Flag to disable conversion of Hash keys to Symbols.
    attr_accessor :disable_hash_keys_to_symbols

    # Hash of namespaces (keys) and XML nodes (values) to apply these
    # namespaces to.
    attr_accessor :nodes_to_namespace

    # Shortcut method for translating between XML Strings and Ruby Hashes.
    # Delegates to +xml_to_hash+ in case +source+ is a String or delegates
    # to +hash_to_xml+ in case +source+ is a Hash. Returns nil otherwise.
    def [](source, root_node = nil)
      case source
        when String
          xml_to_hash(source, root_node)
        when Hash
          hash_to_xml(source)
        else
          nil
      end
    end

    # Yields this class to a given +block+ for wrapping the setup of multiple
    # flags at once.
    def setup
      yield self if block_given?
    end

    # Translates a given +xml+ String into a Ruby Hash.
    #
    # Starts parsing at the XML root node by default. Accepts an optional
    # +root_node+ parameter for defining a custom root node to start parsing
    # at using an XPath-Expression (Hpricot search).
    #
    # Notice that both namespaces and attributes get removed and the root node
    # itself won't be included in the Hash.
    #
    # ==== Examples
    #
    #   xml = '<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
    #       <soap:Body>
    #         <ns2:authenticateResponse xmlns:ns2="http://v1_0.ws.example.com/">
    #           <return>
    #             <apricot>
    #               <eats>Gorilla</eats>
    #             </apricot>
    #           </return>
    #         </ns2:authenticateResponse>
    #       </soap:Body>
    #     </soap:Envelope>'
    #
    #   ApricotEatsGorilla.xml_to_hash(xml)
    #   # => { :body => { :authenticate_response => { :return => { :apricot => { :eats => "Gorilla" } } } } }
    #
    #   ApricotEatsGorilla.xml_to_hash(xml, "//return")
    #   # => { :apricot => { :eats => "Gorilla" } }
    def xml_to_hash(xml, root_node = nil)
      doc = Hpricot.XML remove_whitespace(xml)
      root = root_node ? doc.search(root_node) : doc.root

      return nil if root.nil? || (root.respond_to?(:size) && root.size == 0)
      if !root.respond_to? :each
        xml_node_to_hash(root)
      elsif root.size == 1
        single_xml_root_node_to_hash(root)
      else
        multiple_xml_root_nodes_to_hash(root)
      end
    end

    # Translates a given Ruby +hash+ into an XML String.
    #
    # ==== Examples
    #
    #   hash = { :apricot => { :eats => "Gorilla" } }
    #   ApricotEatsGorilla.hash_to_xml(hash)
    #
    #   # => "<apricot><eats>Gorilla</eats></apricot>"
    #
    #   hash = { :apricot => { :eats => ["Gorillas", "Snakes"] } }
    #   ApricotEatsGorilla.hash_to_xml(hash)
    #
    #   # => "<apricot><eats>Gorillas</eats><eats>Snakes</eats></apricot>"
    def hash_to_xml(hash)
      nested_data_to_xml(hash.keys.first, hash.values.first)
    end

    # Builds a SOAP request envelope and includes the content of a given
    # +block+ into the envelope body. Accepts a Hash of additional +namespaces+
    # to set.
    #
    # ==== Examples
    #
    #   ApricotEatsGorilla.soap_envelope do
    #     "<apricot><eats>Gorilla</eats></apricot>"
    #   end
    #
    #   # => '<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/">
    #   # =>    <env:Body>
    #   # =>      <apricot><eats>Gorilla</eats></apricot>
    #   # =>    </env:Body>
    #   # =>  </env:Envelope>'
    #
    #   ApricotEatsGorilla.soap_envelope(:wsdl => "http://example.com") { "pureText" }
    #
    #   # => '<env:Envelope xmlns:env="http://schemas.xmlsoap.org/soap/envelope/" xmlns:wsdl="http://example.com">
    #   # =>    <env:Body>
    #   # =>      pureText
    #   # =>    </env:Body>
    #   # =>  </env:Envelope>'
    def soap_envelope(namespaces = {})
      namespaces[:env] = "http://schemas.xmlsoap.org/soap/envelope/"

      xml_node("env:Envelope", namespaces) do
        xml_node("env:Body") { yield if block_given? }
      end
    end

  private

    # Translates a single XML root node to a Ruby Hash.
    def single_xml_root_node_to_hash(root)
      if root.first.children.first.kind_of? Hpricot::Text
        map_xml_value(root.first.children.to_s)
      else
        xml_node_to_hash(root.first)
      end
    end

    # Translates multiple XML root nodes to a Ruby Hash.
    def multiple_xml_root_nodes_to_hash(root)
      root.map do |node|
        if node.children.first.kind_of? Hpricot::Text
          map_xml_value(node.children.to_s)
        else
          xml_node_to_hash(node)
        end
      end
    end

    # Iterates through a given Hpricot +element+ and returns a Ruby Hash
    # equal to the XML content of the given element.
    def xml_node_to_hash(element)
      hash = {}

      element.each_child do |child|
        key = create_hash_key(child.name)
        value = create_hash_value(child)

        case hash[key]
          when Array
            hash[key] << value
          when nil
            hash[key] = value
          else
            hash[key] = [ hash[key].dup, value ]
        end
      end

      hash
    end

    # Returns a Hash key for +xml_node_to_hash+ by a given +name+.
    def create_hash_key(name)
      key = XMLNode.new(name)
      key.strip_namespace!
      key.to_snake_case! unless disable_hash_keys_to_snake_case
      key = disable_hash_keys_to_symbols ? key.to_s : key.to_sym
    end

    # Returns a Hash value for +xml_node_to_hash+ by a given +value+.
    def create_hash_value(value)
      if value.children.nil? || value.children.empty?
        nil
      elsif value.children.size == 1 && value.children.first.text?
        map_xml_value(value.children.first.to_html)
      else
        xml_node_to_hash(value)
      end
    end

    # Expects a Hash +key+ and a Hash +value+. Iterates through the given Hash
    # +value+ and returns an XML String of the given Hash structure.
    def nested_data_to_xml(key, value)
      case value
        when Array
          value.map { |subitem| nested_data_to_xml(key, subitem) }.join
        when Hash
          xml_node(key) do
            sort_hash_keys(value).map do |subkey, subvalue|
              case subvalue
              when Array
                subvalue.map { |subitem| nested_data_to_xml(subkey, subitem) }.join
              when Hash
                nested_data_to_xml(subkey, subvalue)
              else
                xml_node(subkey) { map_hash_value(subvalue) } if map_hash_value(subvalue)
              end
            end.join
          end
        else
          xml_node(key) { map_hash_value(value) } if map_hash_value(value)
      end
    end

    # Returns an XML tag with a given +name+. Accepts a +block+ for tag content.
    # Defaults to returning an empty-element tag in case no block was given.
    # Also accepts a Hash of +attributes+ to be added to the XML tag.
    def xml_node(name, attributes = {})
      node = XMLNode.new(name.to_s)
      node.to_lower_camel_case! unless disable_tag_names_to_lower_camel_case
      node.namespace_from_hash!(nodes_to_namespace)
      node.attributes = sort_hash_keys(attributes)
      node.body = yield if block_given?
      node.to_tag
    end

    # Removes whitespace between tags of a given +xml+ String.
    def remove_whitespace(xml)
      xml.gsub(/(>)\s*(<)/, '\1\2')
    end

    # Converts XML values to more natural Ruby objects.
    def map_xml_value(value)
      case value
        when "true"  then true
        when "false" then false
        else              value
      end
    end

    # Converts Hash values into valid XML values.
    def map_hash_value(value)
      if value.kind_of? DateTime
        value.strftime("%Y-%m-%dT%H:%M:%S")
      elsif value.respond_to? :to_s
        value.to_s
      else
        nil
      end
    end

    # Returns a sorted version of a given +hash+ if +sort_keys+ is enabled.
    def sort_hash_keys(hash)
      return hash unless sort_keys
      hash.keys.sort_by { |key| key.to_s }.map { |key| [ key, hash[key] ] }
    end

  end
end