module Padrino::Helpers::NumberHelpers

def number_to_currency(number, options = {})
  options.symbolize_keys!
  defaults  = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
  currency  = I18n.translate(:'number.currency.format', :locale => options[:locale], :raise => true) rescue {}
  defaults  = defaults.merge(currency)
  precision = options[:precision] || defaults[:precision]
  unit      = options[:unit]      || defaults[:unit]
  separator = options[:separator] || defaults[:separator]
  delimiter = options[:delimiter] || defaults[:delimiter]
  format    = options[:format]    || defaults[:format]
  separator = '' if precision == 0
  begin
    format.gsub(/%n/, number_with_precision(number,
      :precision => precision,
      :delimiter => delimiter,
      :separator => separator)
    ).gsub(/%u/, unit)
  rescue
    number
  end
end

def number_to_human_size(number, *args)
  return nil if number.nil?
  options = args.extract_options!
  options.symbolize_keys!
  defaults = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
  human    = I18n.translate(:'number.human.format', :locale => options[:locale], :raise => true) rescue {}
  defaults = defaults.merge(human)
  precision ||= (options[:precision] || defaults[:precision])
  separator ||= (options[:separator] || defaults[:separator])
  delimiter ||= (options[:delimiter] || defaults[:delimiter])
  storage_units_format = I18n.translate(:'number.human.storage_units.format', :locale => options[:locale], :raise => true)
  if number.to_i < 1024
    unit = I18n.translate(:'number.human.storage_units.units.byte', :locale => options[:locale], :count => number.to_i, :raise => true)
    storage_units_format.gsub(/%n/, number.to_i.to_s).gsub(/%u/, unit)
  else
    max_exp  = STORAGE_UNITS.size - 1
    number   = Float(number)
    exponent = (Math.log(number) / Math.log(1024)).to_i # Convert to base 1024
    exponent = max_exp if exponent > max_exp # we need this to avoid overflow for the highest unit
    number  /= 1024 ** exponent
    unit_key = STORAGE_UNITS[exponent]
    unit = I18n.translate(:"number.human.storage_units.units.#{unit_key}", :locale => options[:locale], :count => number, :raise => true)
    begin
      escaped_separator = Regexp.escape(separator)
      formatted_number = number_with_precision(number,
        :precision => precision,
        :separator => separator,
        :delimiter => delimiter
      ).sub(/(#{escaped_separator})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_separator}\z/, '')
      storage_units_format.gsub(/%n/, formatted_number).gsub(/%u/, unit)
    rescue
      number
    end
  end
end

def number_to_percentage(number, options = {})
  options.symbolize_keys!
  defaults   = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
  percentage = I18n.translate(:'number.percentage.format', :locale => options[:locale], :raise => true) rescue {}
  defaults  = defaults.merge(percentage)
  precision = options[:precision] || defaults[:precision]
  separator = options[:separator] || defaults[:separator]
  delimiter = options[:delimiter] || defaults[:delimiter]
  begin
    number_with_precision(number,
      :precision => precision,
      :separator => separator,
      :delimiter => delimiter) + "%"
  rescue
    number
  end
end

def number_with_delimiter(number, *args)
  options = args.extract_options!
  options.symbolize_keys!
  defaults = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
  delimiter ||= (options[:delimiter] || defaults[:delimiter])
  separator ||= (options[:separator] || defaults[:separator])
  begin
    parts = number.to_s.split('.')
    parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{delimiter}")
    parts.join(separator)
  rescue
    number
  end
end

def number_with_precision(number, *args)
  options = args.extract_options!
  options.symbolize_keys!
  defaults           = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}
  precision_defaults = I18n.translate(:'number.precision.format', :locale => options[:locale],
                                                                  :raise => true) rescue {}
  defaults           = defaults.merge(precision_defaults)
  precision ||= (options[:precision] || defaults[:precision])
  separator ||= (options[:separator] || defaults[:separator])
  delimiter ||= (options[:delimiter] || defaults[:delimiter])
  begin
    rounded_number = (Float(number) * (10 ** precision)).round.to_f / 10 ** precision
    number_with_delimiter("%01.#{precision}f" % rounded_number,
      :separator => separator,
      :delimiter => delimiter)
  rescue
    number
  end
end