# version: 5

unless ARGV.length == 2
  puts "Usage: differences.rb <previous index file> <current index file>"
  exit
end

def boring?(line)
  line.split('/').include?('temp') or
  line.split('/').include?('recycler')
end

def boring?(str, list)
  str in list
end

boring?('a', 'a b c'.split)

exit

def inventory_from(filename)
  inventory = File.open(filename)
  downcased = inventory.collect do |line|
    line.chomp.downcase
  end
  downcased.reject do |line|
    boring?(line)
  end
end

old_inventory = inventory_from(ARGV[0])
new_inventory = inventory_from(ARGV[1])

num_added = (new_inventory - old_inventory).length
puts "The following #{num_added} files have been added: "
puts new_inventory - old_inventory

puts

num_deleted = (old_inventory - new_inventory).length
puts "The following #{num_deleted} files have been deleted: "
puts old_inventory - new_inventory

puts
num_common = (old_inventory & new_inventory).length
puts "A total of #{num_common} common files."