class RuboCop::MagicComment

def self.parse(comment)
  case comment
  when EmacsComment::REGEXP then EmacsComment.new(comment)
  when VimComment::REGEXP   then VimComment.new(comment)
  else
    SimpleComment.new(comment)
  end
end

def any?
  frozen_string_literal_specified? ||
    encoding_specified? ||
    shareable_constant_value_specified? ||
    typed_specified?
end

def encoding_specified?
  specified?(encoding)
end

def extract(pattern)
  @comment[pattern, 1]
end

def frozen_string_literal
  return unless (setting = extract_frozen_string_literal)
  case setting
  when 'true'  then true
  when 'false' then false
  else
    setting
  end
end

def frozen_string_literal?
  frozen_string_literal == true
end

def frozen_string_literal_specified?
  specified?(frozen_string_literal)
end

def initialize(comment)
  @comment = comment
end

def shareable_constant_value
  extract_shareable_constant_value
end

def shareable_constant_value_specified?
  specified?(shareable_constant_value)
end

def specified?(value)
  !value.nil?
end

def typed
  extract_typed
end

def typed_specified?
  specified?(extract_typed)
end

def valid?
  @comment.start_with?('#') && any?
end

def valid_literal_value?
  [true, false].include?(frozen_string_literal)
end

def valid_shareable_constant_value?
  %w[none literal experimental_everything experimental_copy].include?(shareable_constant_value)
end