require 'active_support/core_ext/big_decimal/conversions'
require 'active_support/number_helper'

class Numeric

  # Provides options for converting numbers into formatted strings.
  # Options are provided for phone numbers, currency, percentage,
  # precision, positional notation, file size and pretty printing.
  #
  # ==== Options
  #
  # For details on which formats use which options, see ActiveSupport::NumberHelper
  #
  # ==== Examples
  #
  #  Phone Numbers:
  #  5551234.to_s(:phone)                                     # => 555-1234
  #  1235551234.to_s(:phone)                                  # => 123-555-1234
  #  1235551234.to_s(:phone, area_code: true)                 # => (123) 555-1234
  #  1235551234.to_s(:phone, delimiter: ' ')                  # => 123 555 1234
  #  1235551234.to_s(:phone, area_code: true, extension: 555) # => (123) 555-1234 x 555
  #  1235551234.to_s(:phone, country_code: 1)                 # => +1-123-555-1234
  #  1235551234.to_s(:phone, country_code: 1, extension: 1343, delimiter: '.')
  #  # => +1.123.555.1234 x 1343
  #
  #  Currency:
  #  1234567890.50.to_s(:currency)                 # => $1,234,567,890.50
  #  1234567890.506.to_s(:currency)                # => $1,234,567,890.51
  #  1234567890.506.to_s(:currency, precision: 3)  # => $1,234,567,890.506
  #  1234567890.506.to_s(:currency, locale: :fr)   # => 1 234 567 890,51 €
  #  -1234567890.50.to_s(:currency, negative_format: '(%u%n)')
  #  # => ($1,234,567,890.50)
  #  1234567890.50.to_s(:currency, unit: '&pound;', separator: ',', delimiter: '')
  #  # => &pound;1234567890,50
  #  1234567890.50.to_s(:currency, unit: '&pound;', separator: ',', delimiter: '', format: '%n %u')
  #  # => 1234567890,50 &pound;
  #
  #  Percentage:
  #  100.to_s(:percentage)                                  # => 100.000%
  #  100.to_s(:percentage, precision: 0)                    # => 100%
  #  1000.to_s(:percentage, delimiter: '.', separator: ',') # => 1.000,000%
  #  302.24398923423.to_s(:percentage, precision: 5)        # => 302.24399%
  #  1000.to_s(:percentage, locale: :fr)                    # => 1 000,000%
  #  100.to_s(:percentage, format: '%n  %')                 # => 100.000  %
  #
  #  Delimited:
  #  12345678.to_s(:delimited)                     # => 12,345,678
  #  12345678.05.to_s(:delimited)                  # => 12,345,678.05
  #  12345678.to_s(:delimited, delimiter: '.')     # => 12.345.678
  #  12345678.to_s(:delimited, delimiter: ',')     # => 12,345,678
  #  12345678.05.to_s(:delimited, separator: ' ')  # => 12,345,678 05
  #  12345678.05.to_s(:delimited, locale: :fr)     # => 12 345 678,05
  #  98765432.98.to_s(:delimited, delimiter: ' ', separator: ',')
  #  # => 98 765 432,98
  #
  #  Rounded:
  #  111.2345.to_s(:rounded)                                      # => 111.235
  #  111.2345.to_s(:rounded, precision: 2)                        # => 111.23
  #  13.to_s(:rounded, precision: 5)                              # => 13.00000
  #  389.32314.to_s(:rounded, precision: 0)                       # => 389
  #  111.2345.to_s(:rounded, significant: true)                   # => 111
  #  111.2345.to_s(:rounded, precision: 1, significant: true)     # => 100
  #  13.to_s(:rounded, precision: 5, significant: true)           # => 13.000
  #  111.234.to_s(:rounded, locale: :fr)                          # => 111,234
  #  13.to_s(:rounded, precision: 5, significant: true, strip_insignificant_zeros: true)
  #  # => 13
  #  389.32314.to_s(:rounded, precision: 4, significant: true)    # => 389.3
  #  1111.2345.to_s(:rounded, precision: 2, separator: ',', delimiter: '.')
  #  # => 1.111,23
  #
  #  Human-friendly size in Bytes:
  #  123.to_s(:human_size)                                   # => 123 Bytes
  #  1234.to_s(:human_size)                                  # => 1.21 KB
  #  12345.to_s(:human_size)                                 # => 12.1 KB
  #  1234567.to_s(:human_size)                               # => 1.18 MB
  #  1234567890.to_s(:human_size)                            # => 1.15 GB
  #  1234567890123.to_s(:human_size)                         # => 1.12 TB
  #  1234567.to_s(:human_size, precision: 2)                 # => 1.2 MB
  #  483989.to_s(:human_size, precision: 2)                  # => 470 KB
  #  1234567.to_s(:human_size, precision: 2, separator: ',') # => 1,2 MB
  #  1234567890123.to_s(:human_size, precision: 5)           # => "1.1228 TB"
  #  524288000.to_s(:human_size, precision: 5)               # => "500 MB"
  #
  #  Human-friendly format:
  #  123.to_s(:human)                                       # => "123"
  #  1234.to_s(:human)                                      # => "1.23 Thousand"
  #  12345.to_s(:human)                                     # => "12.3 Thousand"
  #  1234567.to_s(:human)                                   # => "1.23 Million"
  #  1234567890.to_s(:human)                                # => "1.23 Billion"
  #  1234567890123.to_s(:human)                             # => "1.23 Trillion"
  #  1234567890123456.to_s(:human)                          # => "1.23 Quadrillion"
  #  1234567890123456789.to_s(:human)                       # => "1230 Quadrillion"
  #  489939.to_s(:human, precision: 2)                      # => "490 Thousand"
  #  489939.to_s(:human, precision: 4)                      # => "489.9 Thousand"
  #  1234567.to_s(:human, precision: 4,
  #                   significant: false)                   # => "1.2346 Million"
  #  1234567.to_s(:human, precision: 1,
  #                   separator: ',',
  #                   significant: false)                   # => "1,2 Million"
  def to_formatted_s(format = :default, options = {})
    case format
    when :phone
      return ActiveSupport::NumberHelper.number_to_phone(self, options)
    when :currency
      return ActiveSupport::NumberHelper.number_to_currency(self, options)
    when :percentage
      return ActiveSupport::NumberHelper.number_to_percentage(self, options)
    when :delimited
      return ActiveSupport::NumberHelper.number_to_delimited(self, options)
    when :rounded
      return ActiveSupport::NumberHelper.number_to_rounded(self, options)
    when :human
      return ActiveSupport::NumberHelper.number_to_human(self, options)
    when :human_size
      return ActiveSupport::NumberHelper.number_to_human_size(self, options)
    else
      self.to_default_s
    end
  end

  klasses = [Float, BigDecimal]
  # Ruby 2.4+ unifies Fixnum & Bignum into Integer.
  if 0.class == Integer
    klasses << Integer
  else
    klasses << Fixnum << Bignum
  end

  klasses.each do |klass|
    klass.send(:alias_method, :to_default_s, :to_s)

    klass.send(:define_method, :to_s) do |*args|
      if args[0].is_a?(Symbol)
        format = args[0]
        options = args[1] || {}

        self.to_formatted_s(format, options)
      else
        to_default_s(*args)
      end
    end
  end
end
