require "rufus-scheduler"

class Drill
  attr_reader :responder, :current_question, :scheduler, :questions
  attr_accessor :length, :participants, :timer_job_id

  def initialize(responder: nil, scheduler: Rufus::Scheduler.new)
    @responder = responder
    @participants = []
    @length = "10m"
    @running = false
    @scheduler = scheduler
    @time_is_up = false
    @questions = []
  end

  def respond(response)
    responder.call response
  end

  def can_handle_message?(message)
    true
  end

  ACTIONS = %w[join leave start stop]
  CUSTOMIZATIONS = %w[length]

  def handle_message(message)
    if ACTIONS.include? message.content
      return send("handle_#{message.content.downcase}", message)
    elsif customization = CUSTOMIZATIONS.find { |c| message.content.start_with?("#{c} ") }
      return send("handle_customize_#{customization}", message)
    end
    return unless running?
    return unless message.author == current_question_target
    
    handle_question_response(message)
  end

  def handle_join(message)
    return respond "The drill's already started!" if running?

    if participants.include? message.author
      respond "You've already joined"
    else
      self.participants << message.author
      respond "#{message.author.display_name} has joined"
    end
  end

  def handle_leave(message)
    return respond "The drill's already started!" if running?

    if participants.include? message.author
      self.participants -= [message.author]
      respond "#{message.author.display_name} has left"
    else
      respond "You aren't a participant"
    end
  end

  def handle_start(message)
    return respond "The drill's already started!" if running?
    return respond "Nobody has joined the drill! Type `join` to join it!" if participants.empty?

    @running = true
    @time_is_up = false
    self.timer_job_id = scheduler.in(length){ @time_is_up = true }
    respond "Drill started!"
    participants.shuffle!
    @questions = []
    next_question!
  end

  def handle_stop(message)
    return respond "The drill's not running yet" unless running?

    scheduler.unschedule(timer_job_id) if timer_job_id

    end_drill!
  end

  def handle_customize_length(message)
    return respond "The drill's already started!" if running?

    cmd, desired_length = message.content.split
    return respond "Please specify a length" unless desired_length

    self.length = desired_length
    respond "Drill length set to #{desired_length}"
  end

  def handle_question_response(message)
    if current_question.answer message.content
      respond "Correct!"
    else
      respond "Incorrect: #{current_question.correct_answer}"
    end

    next_question!
  end

  def next_question!
    return end_drill! if time_is_up?

    self.participants = participants.rotate

    generate_question
    respond "#{current_question_target.display_name}: #{current_question.question_text}"
  end

  def end_drill!
    respond "Lesson's over!"
    questions.group_by(&:target).each do |target, target_questions|
      correct_count = target_questions.select(&:correct?).count
      total_count = target_questions.count
      percentage = "#{((correct_count.to_f / total_count) * 100).to_i}%"
      respond "#{target.display_name} got #{correct_count} out of #{total_count} correct (#{percentage})"
    end

    @running = false
    @participants = []
  end

  def generate_question
    q = Question.new current_question_target
    questions << q
    @current_question = q
  end

  def current_question_target
    participants.first
  end

  def running?
    @running
  end

  def time_is_up?
    @time_is_up
  end

  class Question
    attr_reader :question_text, :correct_answer, :target
    attr_accessor :given_answer

    def initialize(target)  # some kind of config here
      @target = target

      value = (1..100).to_a.sample
      @question_text = "Type the number #{value}"
      @correct_answer = value.to_s
    end

    def answer(response)
      @given_answer = response
      correct?
    end

    def correct?
      given_answer == correct_answer
    end
  end
end