class Soundex

# File lib/soundex.rb, line 5
def initialize input
  self.original = input
  
  process input if !input.nil? && input.length > 0
end

# File lib/soundex.rb, line 37
def process input
  first_letter = input[0]
  input = input.downcase
  input = remove_neighbors(input)
  input = strip_vowels(input)

  input = input[1..-1] unless first_letter.downcase.match(/[aeiouyhw]/)
  input = to_numbers(input)
  
  soundex = first_letter + input
  soundex = soundex.ljust(4, '0')
  self.soundex = soundex[0..3]
end

# File lib/soundex.rb, line 11
def remove_neighbors input
  text = input.dup
  text.gsub!(/[bfpv][hw]{0,1}[bfpv]/) { |m| m[0] }
  text.gsub!(/[cgjkqsxz][hw]{0,1}[cgjkqsxz]/) { |m| m[0] }
  text.gsub!(/[dt][hw]{0,1}[dt]/) { |m| m[0] }
  text.gsub!(/l[hw]{0,1}l/, 'l')
  text.gsub!(/[mn][hw]{0,1}[mn]/) { |m| m[0] }
  text.gsub!(/r[hw]{0,1}r/, 'r')
  text
end

# File lib/soundex.rb, line 22
def strip_vowels input
  input.gsub(/[aeiouyhw]/, '')
end

# File lib/soundex.rb, line 26
def to_numbers input
  text = input.dup
  text.gsub!(/[bfpv]/, '1')
  text.gsub!(/[cgjkqsxz]/, '2')
  text.gsub!(/[dt]/, '3')
  text.gsub!(/[l]/, '4')
  text.gsub!(/[mn]/, '5')
  text.gsub!(/r/, '6')
  text
end

# File lib/soundex.rb, line 51
def to_s
  self.soundex
end