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
  (supported_styles - [style]).first
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
  if style.nil?
    no_acceptable_style!
  elsif style.is_a?(Array)
    if style.empty?
      no_acceptable_style!
    else
      config_to_allow_offenses[parameter_name] = style[0]
    end
  else
    config_to_allow_offenses[parameter_name] = style
  end
end

def no_acceptable_style!
  self.config_to_allow_offenses = { 'Enabled' => false }
  Formatter::DisabledConfigFormatter.detected_styles[cop_name] = []
end

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

def opposite_style_detected
  style_detected(alternative_style)
end

def parameter_name
  'EnforcedStyle'
end

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

def style_detected(detected)
  # `detected` can be a single style, or an Array of possible styles
  # (if there is more than one which matches the observed code)
  return if no_acceptable_style?
  if detected.is_a?(Array)
    detected.map!(&:to_s)
  else
    detected = detected.to_s
  end
  if !detected_style # we haven't observed any specific style yet
    self.detected_style = detected
  elsif detected_style.is_a?(Array)
    self.detected_style &= [*detected]
  elsif detected.is_a?(Array)
    no_acceptable_style! unless detected.include?(detected_style)
  else
    no_acceptable_style! unless detected_style == detected
  end
end

def supported_styles
  @supported_styles ||= cop_config['SupportedStyles'].map(&:to_sym)
end

def unexpected_style_detected(unexpected)
  style_detected(unexpected)
end