module Fossil
  # Provides methods for converting numbers into formatted strings.
  # Methods are provided for phone numbers, currency, percentage,
  # precision, positional notation, and file size.
  module NumberHelper
    # Formats a +number+ into a US phone number (e.g., (555) 123-9876). You can customize the format
    # in the +options+ hash.
    #
    # ==== Options
    # * <tt>:area_code</tt>  - Adds parentheses around the area code.
    # * <tt>:delimiter</tt>  - Specifies the delimiter to use (defaults to "-").
    # * <tt>:extension</tt>  - Specifies an extension to add to the end of the
    #   generated number.
    # * <tt>:country_code</tt>  - Sets the country code for the phone number.
    #
    # ==== Examples
    #  number_to_phone(5551234)                                           # => 555-1234
    #  number_to_phone(1235551234)                                        # => 123-555-1234
    #  number_to_phone(1235551234, :area_code => true)                    # => (123) 555-1234
    #  number_to_phone(1235551234, :delimiter => " ")                     # => 123 555 1234
    #  number_to_phone(1235551234, :area_code => true, :extension => 555) # => (123) 555-1234 x 555
    #  number_to_phone(1235551234, :country_code => 1)                    # => +1-123-555-1234
    #
    #  number_to_phone(1235551234, :country_code => 1, :extension => 1343, :delimiter => ".")
    #  => +1.123.555.1234 x 1343
    def number_to_phone(number, options = {})
      number       = number.to_s.strip unless number.nil?
      options      = options.symbolize_keys
      area_code    = options[:area_code] || nil
      delimiter    = options[:delimiter] || "-"
      extension    = options[:extension].to_s.strip || nil
      country_code = options[:country_code] || nil

      begin
        str = ""
        str << "+#{country_code}#{delimiter}" unless country_code.blank?
        str <<
                if area_code
                  number.gsub!(/([0-9]{1,3})([0-9]{3})([0-9]{4}$)/, "(\\1) \\2#{delimiter}\\3")
                else
                  number.gsub!(/([0-9]{0,3})([0-9]{3})([0-9]{4})$/, "\\1#{delimiter}\\2#{delimiter}\\3")
                  number.starts_with?('-') ? number.slice!(1..-1) : number
                end
        str << " x #{extension}" unless extension.blank?
        str
      rescue
        number
      end
    end

    # Formats a +number+ into a currency string (e.g., $13.65). You can customize the format
    # in the +options+ hash.
    #
    # ==== Options
    # * <tt>:precision</tt>  -  Sets the level of precision (defaults to 2).
    # * <tt>:unit</tt>       - Sets the denomination of the currency (defaults to "$").
    # * <tt>:separator</tt>  - Sets the separator between the units (defaults to ".").
    # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to ",").
    # * <tt>:format</tt>     - Sets the format of the output string (defaults to "%u%n"). The field types are:
    #
    #     %u  The currency unit
    #     %n  The number
    #
    # ==== Examples
    #  number_to_currency(1234567890.50)                    # => $1,234,567,890.50
    #  number_to_currency(1234567890.506)                   # => $1,234,567,890.51
    #  number_to_currency(1234567890.506, :precision => 3)  # => $1,234,567,890.506
    #
    #  number_to_currency(1234567890.50, :unit => "&pound;", :separator => ",", :delimiter => "")
    #  # => &pound;1234567890,50
    #  number_to_currency(1234567890.50, :unit => "&pound;", :separator => ",", :delimiter => "", :format => "%n %u")
    #  # => 1234567890,50 &pound;

    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

    # Formats a +number+ as a percentage string (e.g., 65%). You can customize the
    # format in the +options+ hash.
    #
    # ==== Options
    # * <tt>:precision</tt>  - Sets the level of precision (defaults to 3).
    # * <tt>:separator</tt>  - Sets the separator between the units (defaults to ".").
    # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to "").
    #
    # ==== Examples
    #  number_to_percentage(100)                                        # => 100.000%
    #  number_to_percentage(100, :precision => 0)                       # => 100%
    #  number_to_percentage(1000, :delimiter => '.', :separator => ',') # => 1.000,000%
    #  number_to_percentage(302.24398923423, :precision => 5)           # => 302.24399%

    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

    # Formats a +number+ with grouped thousands using +delimiter+ (e.g., 12,324). You can
    # customize the format in the +options+ hash.
    #
    # ==== Options
    # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to ",").
    # * <tt>:separator</tt>  - Sets the separator between the units (defaults to ".").
    #
    # ==== Examples
    #  number_with_delimiter(12345678)                        # => 12,345,678
    #  number_with_delimiter(12345678.05)                     # => 12,345,678.05
    #  number_with_delimiter(12345678, :delimiter => ".")     # => 12.345.678
    #  number_with_delimiter(12345678, :separator => ",")     # => 12,345,678
    #  number_with_delimiter(98765432.98, :delimiter => " ", :separator => ",")
    #  # => 98 765 432,98
    #
    # You can still use <tt>number_with_delimiter</tt> with the old API that accepts the
    # +delimiter+ as its optional second and the +separator+ as its
    # optional third parameter:
    #  number_with_delimiter(12345678, " ")                     # => 12 345.678
    #  number_with_delimiter(12345678.05, ".", ",")             # => 12.345.678,05

    def number_with_delimiter(number, *args)
      options = args.extract_options!
      options.symbolize_keys!

      defaults = I18n.translate(:'number.format', :locale => options[:locale], :raise => true) rescue {}

      unless args.empty?
        ActiveSupport::Deprecation.warn('number_with_delimiter takes an option hash ' +
                'instead of separate delimiter and precision arguments.', caller)
        delimiter = args[0] || defaults[:delimiter]
        separator = args[1] || defaults[:separator]
      end

      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

    # Formats a +number+ with the specified level of <tt>:precision</tt> (e.g., 112.32 has a precision of 2).
    # You can customize the format in the +options+ hash.
    #
    # ==== Options
    # * <tt>:precision</tt>  - Sets the level of precision (defaults to 3).
    # * <tt>:separator</tt>  - Sets the separator between the units (defaults to ".").
    # * <tt>:delimiter</tt>  - Sets the thousands delimiter (defaults to "").
    #
    # ==== Examples
    #  number_with_precision(111.2345)                    # => 111.235
    #  number_with_precision(111.2345, :precision => 2)   # => 111.23
    #  number_with_precision(13, :precision => 5)         # => 13.00000
    #  number_with_precision(389.32314, :precision => 0)  # => 389
    #  number_with_precision(1111.2345, :precision => 2, :separator => ',', :delimiter => '.')
    #  # => 1.111,23
    #
    # You can still use <tt>number_with_precision</tt> with the old API that accepts the
    # +precision+ as its optional second parameter:
    #   number_with_precision(number_with_precision(111.2345, 2)   # => 111.23

    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)

      unless args.empty?
        ActiveSupport::Deprecation.warn('number_with_precision takes an option hash ' +
                'instead of a separate precision argument.', caller)
        precision = args[0] || defaults[:precision]
      end

      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

  end
end