instamemories.rb

require 'psych'

class MemoryPicker

  STORAGE_NAME = "picked.yml"

  def initialize(path)
    @path = path
    @storage = read_or_initialize_storage
  end

  def pick
    memory_options = Dir.glob(File.join(@path, "**/*.jpg"))
    return if memory_options.empty?
    option = @storage.last
    while @storage.include?(option) || !option do
      option = memory_options.sample
    end
    @storage << option
    save
    option
  end

  def read_or_initialize_storage
    return [] unless File.exists?(storage_path)
    Psych.load_file(storage_path, fallback: [])
  end

  def storage_path
    @storage_path ||= File.join(@path, STORAGE_NAME)
  end

  def save
    Psych.dump(@storage, File.open(storage_path, "w"))
  end

end

if __FILE__ == $0
  puts MemoryPicker.new(ARGV[0]).pick
end