module RuboCop::Cop::ConfigurableEnforcedStyle

def alternative_style
  if supported_styles.size != 2
    raise 'alternative_style can only be used when there are exactly ' \
         '2 SupportedStyles'
  end
  alternative_styles.first
end

def alternative_styles
  (supported_styles - [style])
end

def ambiguous_style_detected(*possibilities)
  style_detected(possibilities)
end

def correct_style_detected
  style_detected(style)
end

def detected_style
  Formatter::DisabledConfigFormatter.detected_styles[cop_name] ||= nil
end

def detected_style=(style)
  Formatter::DisabledConfigFormatter.detected_styles[cop_name] = style
end

def no_acceptable_style!
  self.config_to_allow_offenses = { 'Enabled' => false }
end

def no_acceptable_style?
  config_to_allow_offenses['Enabled'] == false
end

def opposite_style_detected
  style_detected(alternative_style)
end

def style
  @style ||= begin
    s = cop_config[style_parameter_name].to_sym
    unless supported_styles.include?(s)
      raise "Unknown style #{s} selected!"
    end
    s
  end
end

def style_detected(detected)
  return if no_acceptable_style?
  # `detected` can be a single style or an Array of possible styles
  # (if there is more than one which matches the observed code)
  detected_as_strings = Array(detected).map(&:to_s)
  updated_list = if detected_style
                   detected_style & detected_as_strings
                 else
                   # We haven't observed any specific style yet.
                   detected_as_strings
                 end
  if updated_list.empty?
    no_acceptable_style!
  else
    self.detected_style = updated_list
    config_to_allow_offenses[style_parameter_name] = updated_list.first
  end
end

def style_parameter_name
  'EnforcedStyle'
end

def supported_styles
  @supported_styles ||= begin
    supported_styles = Util.to_supported_styles(style_parameter_name)
    cop_config[supported_styles].map(&:to_sym)
  end
end

def unexpected_style_detected(unexpected)
  style_detected(unexpected)
end