class ActiveSupport::NumberHelper::NumberToCurrencyConverter

def convert
  format = options[:format]
  number_d = valid_bigdecimal
  if number_d
    if number_d.negative?
      number_d = number_d.abs
      format = options[:negative_format] if (number_d * 10**options[:precision]) >= 0.5
    end
    number_s = NumberToRoundedConverter.convert(number_d, options)
  else
    number_s = number.to_s.strip
    format = options[:negative_format] if number_s.sub!(/^-/, "")
  end
  format.gsub("%n", number_s).gsub("%u", options[:unit])
end

def i18n_opts
  # Set International negative format if it does not exist
  i18n = i18n_format_options
  i18n[:negative_format] ||= "-#{i18n[:format]}" if i18n[:format]
  i18n
end

def options
  @options ||= begin
    defaults = default_format_options.merge(i18n_opts)
    # Override negative format if format options are given
    defaults[:negative_format] = "-#{opts[:format]}" if opts[:format]
    defaults.merge!(opts)
  end
end