require File.expand_path(File.join(File.dirname(__FILE__), '..', '..', 'fathom'))
class Fathom::DiscreteNode < Fathom::Node
  attr_reader :labels

  def initialize(opts={})
    opts[:distribution] ||= :discrete_uniform
    super(opts)
    assert_labels(opts)
  end

  def size
    @size ||= self.labels.length
  end
  alias :length :size

  def rand
    self.labels[self.distribution.rand(self.size)]
  end
  
  # This makes it easier to interface to a belief node
  def likelihood(ignored_value)
    GSL::Vector.ary_to_gv(Array.new(self.size, 1))
  end
  alias :l :likelihood

  protected
    def assert_labels(opts)
      @labels = opts[:labels]
      @labels ||= self.values
      @labels ||= [:true, :false]
      @labels = Array[@labels] unless @labels.is_a?(Array)
      @labels.uniq!
    end
  
end

if __FILE__ == $0
  include Fathom
  # TODO: Is there anything you want to do to run this file on its own?
  # DiscreteNode.new
end