DEFAULT_LESSON_PLAN = [
  [15, "login and catch up on the week"],
  [45, "review chapter vocab and grammar"],
  [15, "answer Seth Clydesdale Genki review questions"],
  [15, "ask closing questions and have Japanese conversation"],
]

class Lesson
  attr_reader :lesson_plan, :channel, :thread, :running

  def initialize(lesson_plan=DEFAULT_LESSON_PLAN)
    @lesson_plan = lesson_plan
    @running = false
  end

  def stop!
    thread.kill if thread
    @running = false
  end

  def start!(channel)
    stop!
    @channel = channel
    @thread = Thread.new do
      @running = true
      lesson_plan.each do |time, message|
        channel.send_message "#{time} minutes to #{message}"
        sleep(time * 60)
      end
      channel.send_message "Lesson over!"
      @running = false
    end
  end

  def running?
    running
  end
end