module ActionView::Helpers::NumberHelper

def number_to_currency(number, options = {})
  return unless number
  options.symbolize_keys!
  options[:delimiter] = ERB::Util.html_escape(options[:delimiter]) if options[:delimiter]
  options[:separator] = ERB::Util.html_escape(options[:separator]) if options[:separator]
  options[:format] = ERB::Util.html_escape(options[:format]) if options[:format]
  options[:negative_format] = ERB::Util.html_escape(options[:negative_format]) if options[:negative_format]
  defaults  = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
  currency  = I18n.translate(:'number.currency.format', :locale => options[:locale], :default => {})
  currency[:negative_format] ||= "-" + currency[:format] if currency[:format]
  defaults  = DEFAULT_CURRENCY_VALUES.merge(defaults).merge!(currency)
  defaults[:negative_format] = "-" + options[:format] if options[:format]
  options   = defaults.merge!(options)
  unit      = options.delete(:unit)
  format    = options.delete(:format)
  if number.to_f < 0
    format = options.delete(:negative_format)
    number = number.respond_to?("abs") ? number.abs : number.sub(/^-/, '')
  end
  begin
    value = number_with_precision(number, options.merge(:raise => true))
    format.gsub(/%n/, ERB::Util.html_escape(value)).gsub(/%u/, ERB::Util.html_escape(unit)).html_safe
  rescue InvalidNumberError => e
    if options[:raise]
      raise
    else
      formatted_number = format.gsub(/%n/, e.number).gsub(/%u/, unit)
      e.number.to_s.html_safe? ? formatted_number.html_safe : formatted_number
    end
  end
end

def number_to_human(number, options = {})
  options.symbolize_keys!
  number = begin
    Float(number)
  rescue ArgumentError, TypeError
    if options[:raise]
      raise InvalidNumberError, number
    else
      return number
    end
  end
  defaults = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
  human    = I18n.translate(:'number.human.format', :locale => options[:locale], :default => {})
  defaults = defaults.merge(human)
  options = options.reverse_merge(defaults)
  #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
  options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)
  inverted_du = DECIMAL_UNITS.invert
  units = options.delete :units
  unit_exponents = case units
  when Hash
    units = Hash[units.map { |k, v| [k, ERB::Util.html_escape(v)] }]
  when String, Symbol
    I18n.translate(:"#{units}", :locale => options[:locale], :raise => true)
  when nil
    I18n.translate(:"number.human.decimal_units.units", :locale => options[:locale], :raise => true)
  else
    raise ArgumentError, ":units must be a Hash or String translation scope."
  end.keys.map{|e_name| inverted_du[e_name] }.sort_by{|e| -e}
  number_exponent = number != 0 ? Math.log10(number.abs).floor : 0
  display_exponent = unit_exponents.find{ |e| number_exponent >= e } || 0
  number  /= 10 ** display_exponent
  unit = case units
  when Hash
    units[DECIMAL_UNITS[display_exponent]] || ''
  when String, Symbol
    I18n.translate(:"#{units}.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
  else
    I18n.translate(:"number.human.decimal_units.units.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
  end
  decimal_format = options[:format] || I18n.translate(:'number.human.decimal_units.format', :locale => options[:locale], :default => "%n %u")
  formatted_number = number_with_precision(number, options)
  decimal_format.gsub(/%n/, formatted_number).gsub(/%u/, unit).strip.html_safe
end

def number_to_human_size(number, options = {})
  options.symbolize_keys!
  number = begin
    Float(number)
  rescue ArgumentError, TypeError
    if options[:raise]
      raise InvalidNumberError, number
    else
      return number
    end
  end
  defaults = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
  human    = I18n.translate(:'number.human.format', :locale => options[:locale], :default => {})
  defaults = defaults.merge(human)
  options = options.reverse_merge(defaults)
  #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
  options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)
  storage_units_format = I18n.translate(:'number.human.storage_units.format', :locale => options[:locale], :raise => true)
  base = options[:prefix] == :si ? 1000 : 1024
  if number.to_i < base
    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).html_safe
  else
    max_exp  = STORAGE_UNITS.size - 1
    exponent = (Math.log(number) / Math.log(base)).to_i # Convert to base
    exponent = max_exp if exponent > max_exp # we need this to avoid overflow for the highest unit
    number  /= base ** exponent
    unit_key = STORAGE_UNITS[exponent]
    unit = I18n.translate(:"number.human.storage_units.units.#{unit_key}", :locale => options[:locale], :count => number, :raise => true)
    formatted_number = number_with_precision(number, options)
    storage_units_format.gsub(/%n/, formatted_number).gsub(/%u/, unit).html_safe
  end
end

def number_to_percentage(number, options = {})
  return unless number
  options.symbolize_keys!
  options[:delimiter] = ERB::Util.html_escape(options[:delimiter]) if options[:delimiter]
  options[:separator] = ERB::Util.html_escape(options[:separator]) if options[:separator]
  defaults   = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
  percentage = I18n.translate(:'number.percentage.format', :locale => options[:locale], :default => {})
  defaults  = defaults.merge(percentage)
  options = options.reverse_merge(defaults)
  begin
    "#{number_with_precision(number, options.merge(:raise => true))}%".html_safe
  rescue InvalidNumberError => e
    if options[:raise]
      raise
    else
      e.number.to_s.html_safe? ? "#{e.number}%".html_safe : "#{e.number}%"
    end
  end
end

def number_to_phone(number, options = {})
  return unless number
  begin
    Float(number)
  rescue ArgumentError, TypeError
    raise InvalidNumberError, number
  end if options[:raise]
  number       = number.to_s.strip
  options      = options.symbolize_keys
  area_code    = options[:area_code]
  delimiter    = options[:delimiter] || "-"
  extension    = options[:extension]
  country_code = options[:country_code]
  if area_code
    number.gsub!(/(\d{1,3})(\d{3})(\d{4}$)/,"(\\1) \\2#{delimiter}\\3")
  else
    number.gsub!(/(\d{0,3})(\d{3})(\d{4})$/,"\\1#{delimiter}\\2#{delimiter}\\3")
    number.slice!(0, 1) if number.starts_with?(delimiter) && !delimiter.blank?
  end
  str = []
  str << "+#{country_code}#{delimiter}" unless country_code.blank?
  str << number
  str << " x #{extension}" unless extension.blank?
  ERB::Util.html_escape(str.join)
end

def number_with_delimiter(number, options = {})
  options.symbolize_keys!
  options[:delimiter] = ERB::Util.html_escape(options[:delimiter]) if options[:delimiter]
  options[:separator] = ERB::Util.html_escape(options[:separator]) if options[:separator]
  begin
    Float(number)
  rescue ArgumentError, TypeError
    if options[:raise]
      raise InvalidNumberError, number
    else
      return number
    end
  end
  defaults = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
  options = options.reverse_merge(defaults)
  parts = number.to_s.to_str.split('.')
  parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{options[:delimiter]}")
  parts.join(options[:separator]).html_safe
end

def number_with_precision(number, options = {})
  options.symbolize_keys!
  number = begin
    Float(number)
  rescue ArgumentError, TypeError
    if options[:raise]
      raise InvalidNumberError, number
    else
      return number
    end
  end
  defaults           = I18n.translate(:'number.format', :locale => options[:locale], :default => {})
  precision_defaults = I18n.translate(:'number.precision.format', :locale => options[:locale], :default => {})
  defaults           = defaults.merge(precision_defaults)
  options = options.reverse_merge(defaults)  # Allow the user to unset default values: Eg.: :significant => false
  precision = options.delete :precision
  significant = options.delete :significant
  strip_insignificant_zeros = options.delete :strip_insignificant_zeros
  if significant and precision > 0
    if number == 0
      digits, rounded_number = 1, 0
    else
      digits = (Math.log10(number.abs) + 1).floor
      rounded_number = (BigDecimal.new(number.to_s) / BigDecimal.new((10 ** (digits - precision)).to_f.to_s)).round.to_f * 10 ** (digits - precision)
      digits = (Math.log10(rounded_number.abs) + 1).floor # After rounding, the number of digits may have changed
    end
    precision -= digits
    precision = precision > 0 ? precision : 0  #don't let it be negative
  else
    rounded_number = BigDecimal.new(number.to_s).round(precision).to_f
  end
  formatted_number = number_with_delimiter("%01.#{precision}f" % rounded_number, options)
  if strip_insignificant_zeros
    escaped_separator = Regexp.escape(options[:separator])
    formatted_number.sub(/(#{escaped_separator})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_separator}\z/, '').html_safe
  else
    formatted_number
  end
end