module PolishNumber

# File lib/polish_number.rb, line 28
def self.translate(number, options={})
  if options[:currency] && !CURRENCIES.has_key?(options[:currency])
    raise ArgumentError, "unknown :currency option '#{options[:currency].inspect}'. Choose one from: #{CURRENCIES.inspect}"
  end

  number = number.to_i

  unless (0..999999999).include? number
    raise ArgumentError, 'number should be in 0..999999999 range'
  end

  if number == 0
    result = ZERO.dup
  else
    formatted_number = sprintf('%09.0f', number)
    digits = formatted_number.chars.map { |char| char.to_i }

    result = ''
    result << process_0_999(digits[0..2])
    result << millions(number/1000000, digits[0..2])
    result << ' '
    result << process_0_999(digits[3..5])
    result << thousands(number/1000, digits[3..5])
    result << ' '
    result << process_0_999(digits[6..9])
    result.strip!
  end

  if options[:currency]
    currency = CURRENCIES[options[:currency]]
    result << ' '
    result << currency[classify(number, digits)]
  end

  result
end

# File lib/polish_number.rb, line 97
def self.classify(number, digits)
  if number == 1
    :one
  # all numbers with 2, 3 or 4 at the end, but not teens
  elsif digits && (2..4).include?(digits[-1]) && digits[-2] != 1
    :few
  else
    :many
  end
end

# File lib/polish_number.rb, line 89
def self.millions(number, digits)
  if number == 0
    ''
  else
    MILLIONS[classify(number, digits)]
  end
end

# File lib/polish_number.rb, line 67
def self.process_0_999(digits)
  result = ''
  result << HUNDREDS[digits[0]]

  if digits[1] == 1 && digits[2] != 0
    result << TEENS[digits[2]]
  else
    result << TENS[digits[1]]
    result << UNITIES[digits[2]]
  end

  result
end

# File lib/polish_number.rb, line 81
def self.thousands(number, digits)
  if number == 0
    ''
  else
    THOUSANDS[classify(number, digits)]
  end
end