require 'phonetic/algorithm'

module Phonetic
  # Class for encoding string to Refined Soundex code.
  # A refined soundex code is optimized for spell checking words.
  #
  # @example
  #    Phonetic::RefinedSoundex.encode('Caren')   # => 'C30908'
  #    Phonetic::RefinedSoundex.encode('Hayers')  # => 'H093'
  #    Phonetic::RefinedSoundex.encode('Lambard') # => 'L7081096'
  class RefinedSoundex < Algorithm
    CODE = {
      B: 1, P: 1,
      F: 2, V: 2,
      C: 3, K: 3, S: 3,
      G: 4, J: 4,
      Q: 5, X: 5, Z: 5,
      D: 6, T: 6,
      L: 7,
      M: 8, N: 8,
      R: 9
    }

    # Encode word to its Refined Soundex value
    def self.encode_word(word, options = {})
      w = word.upcase
      res = w[0]
      pg = nil
      w.chars.each do |c|
        g = CODE[c.to_sym] || 0
        if pg != g
          res += g.to_s
          pg = g
        end
      end
      res
    end
  end
end