class Ransack::Nodes::Sort

def build(params)
  params.with_indifferent_access.each do |key, value|
    if key.match(/^(name|dir|ransacker_args)$/)
      self.send("#{key}=", value)
    end
  end
  self
end

def dir=(dir)
  dir = dir.downcase if dir
  @dir =
    if dir == 'asc'.freeze || dir == 'desc'.freeze
      dir
    else
      'asc'.freeze
    end
end

def extract(context, str)
  return unless str
  attr, direction = str.split(/\s+/, 2)
  self.new(context).build(name: attr, dir: direction)
end

def name=(name)
  @name = context.ransackable_alias(name) || name
  context.bind(self, @name)
end

def ransacker_args=(ransack_args)
  @ransacker_args = ransack_args
end

def valid?
  bound? && attr &&
  context.klassify(parent).ransortable_attributes(context.auth_object)
  .include?(attr_name)
end