Split name into first/last name

name_split.rb

# words that indicate last name
#
# da
# de
# de la
# del
# di
# dos
# la
# van der
# vander
# van
# von
# st.
# san
# mc
# mac
#
# Suffixes
#
# Jr
# Sr
# II
# III
# IV
# V
# MD
#
# If there is a surname prefix (per above) we'll split on it, otherwise
# we'll split words, with that last word (plus suffix, if present) being
# the surname.
def split_name(name)
  words = contact_name.split(/\s+/).select { |w| w =~ /[[:alpha:]]/ }
  case
  when words.count == 1
    ['', contact_name]
  when words.count == 2
    [words[0], words[1]]
  else
    if %w{jr sr ii iii iv v md}.include?(words.last.gsub(/[^[:alpha:]]/i, '').downcase)
      last_name_word_count = 2
    else
      last_name_word_count = 1
    end
    first_name_word_count = words.count - last_name_word_count
    found_last_name_prefix = false
    if first_name_word_count > 2
      last_two_words_of_first_name = words[(-last_name_word_count-2)..(-last_name_word_count-1)].join(' ').downcase
      if ['de la', 'van der'].include?(last_two_words_of_first_name)
        last_name_word_count += 2
        found_last_name_prefix = true
      end
    end
    if first_name_word_count > 1 && !found_last_name_prefix
      if %w{da de del di dos la vander van von st san mc mac}.include?(words[-last_name_word_count-1].gsub(/[^[:alpha:]]/, '').downcase)
        last_name_word_count += 1
      end
    end
    first_name_word_count = words.count - last_name_word_count
    [words[0..(first_name_word_count-1)].join(' '), words[-last_name_word_count..-1].join(' ')]
  end
end