class ActiveSupport::NumberHelper::NumberToHumanSizeConverter

def base
  opts[:prefix] == :si ? 1000 : 1024
end

def conversion_format
  translate_number_value_with_default('human.storage_units.format', :locale => options[:locale], :raise => true)
end

def convert
  if opts.key?(:prefix)
    ActiveSupport::Deprecation.warn('The :prefix option of `number_to_human_size` is deprecated and will be removed in Rails 5.1 with no replacement.')
  end
  @number = Float(number)
  # for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
  unless options.key?(:strip_insignificant_zeros)
    options[:strip_insignificant_zeros] = true
  end
  if smaller_than_base?
    number_to_format = number.to_i.to_s
  else
    human_size = number / (base ** exponent)
    number_to_format = NumberToRoundedConverter.convert(human_size, options)
  end
  conversion_format.gsub('%n'.freeze, number_to_format).gsub('%u'.freeze, unit)
end

def exponent
  max = STORAGE_UNITS.size - 1
  exp = (Math.log(number) / Math.log(base)).to_i
  exp = max if exp > max # avoid overflow for the highest unit
  exp
end

def smaller_than_base?
  number.to_i < base
end

def storage_unit_key
  key_end = smaller_than_base? ? 'byte' : STORAGE_UNITS[exponent]
  "human.storage_units.units.#{key_end}"
end

def unit
  translate_number_value_with_default(storage_unit_key, :locale => options[:locale], :count => number.to_i, :raise => true)
end