secret_santa.rb

#!/usr/bin/env ruby

# Choose type of sender, :email or :twilio
SENDER_TYPE = :twilio

$LOAD_PATH << '.'
require 'yaml'
require 'person'
require 'emailer'
require 'email'
require 'twilio_sender' if SENDER_TYPE == :twilio
require 'santa_logger'
require 'pry'

# Do some testing, then set this to true when ready to send
# Will cause logging output to be shushed and mails to be sent
REALLY_SENDING = false

logger = SantaLogger.new

people_config = YAML.load_file('config/people_peer.yml')

people = people_config['people'].map do |attrs|
  Person.new(attrs)
end

santas = people.dup.shuffle
people.each do |person|
  person.santa = santas.delete_at(rand(santas.size))
end

logger.log "Initial Santa assignments:"
people.each do |person|
  logger.log person.with_santa
end

# This is the nice part of Dennis's solution: if there are any invalid
# assignments, they are corrected in as few passes as possible. (I
# originally said "a single pass", but that's not true because the
# `select` that looks for someone to swap santas with is just a
# way of saying "loop through the list of people looking for a match.")
# This works because corrections are made in a way that ensures no new
# invalid assignments are created.
logger.log "Checking assignments for validity"
people.each do |person|
   unless person.santa.can_be_santa_of?(person)
     logger.log "\n#{person} can't get a gift from #{person.santa}! Let's try to fix that..."
     swap_candidates = people.select {|p| person.can_swap_santas_with?(p) }
     raise "Failure! No one can swap santas with #{person}" if swap_candidates.empty?
     logger.log "Any of these can swap santas with #{person}: #{swap_candidates}"
     swapper = swap_candidates.sample
     logger.log "Chose #{swapper} to swap santas with #{person}"
     misplaced_santa = person.santa
     person.santa    = swapper.santa
     swapper.santa   = misplaced_santa
   end
end

logger.log "\n\nFinal Santa assignments:"
people.each do |person|
  logger.log person.with_santa
end

case SENDER_TYPE
when :email
  smtp_config = YAML.load_file('config/smtp.yml')
  emailer     = Emailer.new(
    smtp_config['smtp_server'],
    smtp_config['domain'],
    smtp_config['account_address'],
    smtp_config['account_password']
  )

  people.each do |person|
    message = <<-MESSAGE
   GREETINGS #{person.santa.name.upcase},

   HATS ARE NOW OBSELETE.

   SANTABOT 5000 HAS BEEN ACTIVATED. YOU HAVE BEEN CHOSEN AS A SECRET SANTA.
   YOUR TARGET IS AS FOLLOWS:

   #{person.name.upcase}

   THIS INFORMATION HAS BEEN KEPT SECRET FROM ALL HUMANS BUT YOU.

   IF I, SANTABOT, HAD EMOTIONS, I WOULD WISH YOU A MERRY CHRISTMAS,
   BUT AS IT IS THAT WOULD NOT REALLY MAKE SENSE.

   THAT IS ALL.

   --SANTABOT 5000
   MESSAGE
    email = Email.new(person.santa.email, "SANTABOT 5000: #{Time.now.year} TARGETS", message)
    emailer.send(email)
  end
when :twilio
  twilio_config = YAML.load_file('config/twilio.yml')
  twilio_sender = TwilioSender.new(
    twilio_config['twilio_account_sid'],
    twilio_config['twilio_auth_token'],
    twilio_config['twilio_from_number']
  )

  people.each do |person|
    message = "Hey #{person.santa.name}, koop voor deze huskens-kerst een cadeau voor #{person.name.upcase}"
    twilio_sender.send(person.santa.phone, message)
  end
else
  raise 'Unknown sender type'
end