class ActiveFedora::WithMetadata::MetadataNode

def changed_attributes
  super.tap do |changed|
    changed['type'] = true if type.present? && new_record?
  end
end

def changes_for_update
  ChangeSet.new(self, self, changed_attributes.keys).changes
end

def create_delegating_setter(name)
  file.class.delegate(name, to: :metadata_node)
end

def exec_block(&block)
  class_eval(&block)
end

def initialize(file)
  @file = file
  super(file.uri, ldp_source.graph)
  return unless self.class.type && !type.include?(self.class.type)
  # Workaround for https://github.com/ActiveTriples/ActiveTriples/issues/123
  get_values(:type) << self.class.type
end

def ldp_connection
  ActiveFedora.fedora.connection
end

def ldp_source
  @ldp_source ||= LdpResource.new(ldp_connection, metadata_uri)
end

def metadata_uri
  @metadata_uri ||= if file.new_record?
                      ::RDF::URI.new nil
                    else
                      raise "#{file} must respond_to described_by" unless file.respond_to? :described_by
                      file.described_by
                    end
end

def property(name, options)
  parent_class.delegate name, :"#{name}=", :"#{name}_changed?", to: :metadata_node
  super
end

def save
  raise "Save the file first" if file.new_record?
  SparqlInsert.new(changes_for_update, ::RDF::URI.new(file.uri)).execute(metadata_uri)
  @ldp_source = nil
  true
end

def set_value(*args)
  super
  attribute_will_change! args.first
end