loss_test.rb

#simulating a worker running every X
#a user will ahve to receive a msg every Y interval
#user msg is sent sometime between now and now+X
#next_message_time will have to be set to current_time += Y

#Goal: determine if during a time window of a working processing, if a user is receiving fewer messages than it could because of the offset between 0..X


class SendProcess
  RUN_INTERVAL = 60.0 #1 minute in seconds
  DAY_INTERVAL = 50400 #14 hours in seconds

  def initialize days: nil
    set_day
    @days = days
    @user = User.new(@current_time)
  end

  def stubbed_current_time
    @current_time + rand(0.0..RUN_INTERVAL)
  end

  def run 
    @days.times do 
      while @current_time < @end_time #Add <= for testing (if desired functionality is for process to run at 12th hour)
        if @user.next_msg_time <= @current_time
          @user.send_message(stubbed_current_time)
        end
        @current_time += RUN_INTERVAL
      end
      set_day
      @user.next_msg_time = @current_time
    end

    report
  end

  def set_day
    @current_time = Time.now
    @end_time = @current_time + DAY_INTERVAL
  end

  def report
    puts "User HAS received #{@user.message_count} messages"
    puts "User COULD HAVE received #{(DAY_INTERVAL/User::MSG_INTERVAL).floor * @days} messages"
  end
end

class User
  attr_accessor :next_msg_time, :message_count
  MSG_INTERVAL = 1800.0 #.5 hour in seconds

  def initialize init_time
    @next_msg_time = init_time
    @message_count = 0
  end

  def send_message current_time
    @last_msg_time = @next_msg_time
    @next_msg_time = current_time + MSG_INTERVAL
    @message_count += 1
    # report
  end

  def report
    puts "Current msg time: #{next_msg_time.strftime("%I:%M:%S")}"
    puts "Time until next message: #{(@next_msg_time - @last_msg_time)/60.0}\n"
    puts ""
  end
end

s = SendProcess.new(days: 1)
s.run

#Thesis (with worker running every minute): 
# A user loses one minute every time a message was sent. 
# If the total number of messages that could be sent, given the user's message inteveral, is greater than the user message interval, in minutes, 
# then the total time lost is greater than the user message interval.
# Therefore, at least one message is lost in a given day. Therefore, given that a user cannot receive more than 28 messages in a given day (day_interval = 14 hours)
# and a user message interval is no more than 30 minutes, we will not see loss.