bob_bot_2

visitor.rb

class Visitor
  METHODS_TOBE_IMPLEMENTED = %i(
    respond_to_question respond_to_yell respond_to_silence respond_to_anything)

  attr_reader :message_types

  def initialize(*message_types)
    @message_types = message_types
  end
  
  def self.default
    # NOTE: the message types will be processed in order
    @bot ||= new(Question, Yell, Silence, Anything)
  end

  def respond(text)
    message_types.each do |type|
      message = type.new(text)
      return message.accept(self) if message.valid?
    end
    raise "Can't respond to: #{text || 'nil'}"
  end

  def method_missing(method, *args, &block)
    raise 'Not yet implemented' if METHODS_TOBE_IMPLEMENTED.include?(method)
    super(method, *args, &block)
  end
  
  def respond_to?(method, *args, &block)
    return true if METHODS_TOBE_IMPLEMENTED.include?(method)
    super(method, *args, &block)
  end
end