Birthday helper exercise from Chris Pine's book, Learn to Program

birthday_helper.rb

# Write a program to read in names and birth dates from a text file. 
# It should then ask you for a name. You type one in, and it tells you 
# when that person’s next birthday will be (and, for the truly adventur- 
# ous, how old they will be). The input file should look something like this:
# Christopher Alexander,  Oct  4, 1936
# Christopher Lambert,    Mar 29, 1957
# Christopher Lee,        May 27, 1922
# Christopher Lloyd,      Oct 22, 1938
# Christopher Pine,       Aug  3, 1976
# Christopher Plummer,    Dec 13, 1927
# Christopher Walken,     Mar 31, 1943
# The King of Spain,      Jan  5, 1938
# 
# You’ll probably want to break each line up and put it in a hash, 
# using the name as your key and the date as your value. 
# In other words: words:
# birth_dates['The King of Spain'] = 'Jan 5, 1938'
# (You can store the date in some other format if you prefer.)
# 
# Though you can do it without this tip, your program might look prettier 
# if you use the each_line method for strings. It works pretty much like 
# each does for arrays, but it returns each line of the multiline 
# string one at a time (but with the line endings, 
# so you might need to chomp them). Just thought I’d mention it....


require 'yaml'
file = File.open("birthdaylist.txt")

contents = file.read

lines_array = contents.split("\n");

birthdays = {}

#here we clean up the contents of the text file so we can manipulate it as a hash
lines_array.each do |l|
  date = l[-12..-1].to_s
  man_date = date.split(', ')
  year = man_date[1].to_i
  month = man_date[0][0..2]
 months = ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec']
  #convert month string to month number for time calcs later
  months.each do |m|
    if m == month
     month = months.index(m) + 1
   end
  end
  #remove leading whitespace from date numbers
  day = man_date[0][4..5]
  if day[0] == ' '
    day = day[1].to_i
  else
    day = day[0..1].to_i
  end
 
  
  nameline = l.split(date).to_s
  name_array = nameline.split(',')
  name = name_array[0]
  name = name[2..-1]
  
  birthdays[name] = [year, month, day]
  
end

puts "Who's birthday would you like to know?"
input_name = gets.chomp
birthdays.each do |n,d|
  if n == input_name
   birthtime = Time.new(d[0].to_i,d[1].to_i,d[2].to_i) 
   time = Time.new
   current_year = time.year
   test_date = Time.local(current_year,d[1].to_i,d[2].to_i)
   diff = test_date - Time.now
    if diff > 0 
      next_birthday_age = current_year - birthtime.year
      puts "#{n}'s next birthday is #{d[1]}/#{d[2]} #{time.year}. They will be #{next_birthday_age} years old."
    else
      next_birthday_age = 1 + current_year - birthtime.year
      puts "#{n}'s next birthday is #{d[1]}/#{d[2]} of #{time.year + 1}. They will be #{next_birthday_age} years old."
   end
  end
end