module Tibetan

# File lib/tibetan.rb, line 151
def insert_default_vowel!(string="")
  # 1. after subscript
  if (string.chars & VOWELS).empty?
    index = string.rindex(/#{SUBSCRIPTS.join('|')}/)
    string = string.insert(index+1, DEFAULT_VOWEL) unless index.nil?
  end
  # 2. after consonant, if not added in 1st step
  if (string.chars & VOWELS).empty? && (string.chars & CONSONANTS).any?
    index = string.size > 2 ? 1 : 0
    string = string.insert(index+1, DEFAULT_VOWEL) unless index.nil?
  end
end

# File lib/tibetan.rb, line 134
def transliterate(string="", to=:tibetan)
  string = string.to_s
  
  # Split long phrase into small parts and transliterate separately
  if string.split(SEP).size > 1
    string = string.split(SEP).map do |str|
      transliterate(str)
    end.join(SEP)
  end
  
  insert_default_vowel!(string)

  character_table = Module.const_get(to.to_s.capitalize)::CHARACTER_TABLE
  string.to_s.gsub(/#{Regexp.union(character_table.keys).source}/i, character_table)      
end