require 'date'

def days_diff(date1, date2)
  date1 = Time.new(date1.year, date1.month, date1.day)
  date2 = Time.new(date2.year, date2.month, date2.day)
  return (date1.to_i - date2.to_i)/(3600*24)
end

def count_sessions(array)
  count_session = 1
  last_session = DateTime.strptime(array[array.length-1], "%Y-%m-%d %H:%M:%S")

  consecutive_days = 1

  for i in 2..array.length
    comparing = DateTime.strptime(array[array.length-i], "%Y-%m-%d %H:%M:%S")
    days_between_sessions = days_diff(last_session, comparing)
    if days_between_sessions > 1
      break
    elsif last_session.to_time.to_i - comparing.to_time.to_i > 60*30
      consecutive_days += days_between_sessions
      count_session += 1
      last_session = comparing
    end
  end

  if count_session >= 6 && consecutive_days == 3
    return true
  else
    return false
  end
end

puts count_sessions(['2017-03-10 08:13:11', '2017-03-10 19:01:27', '2017-03-11 07:35:55', '2017-03-11 16:15:11', '2017-03-12 08:01:41', '2017-03-12 17:19:08'])
puts count_sessions(['2017-03-10 18:58:11', '2017-03-10 19:01:27', '2017-03-11 07:35:55', '2017-03-11 16:15:11', '2017-03-12 08:01:41', '2017-03-12 17:19:08'])
puts count_sessions(['2017-03-08 17:11:13', '2017-03-11 17:22:47', '2017-03-11 19:23:51', '2017-03-11 22:03:12', '2017-03-12 08:32:04', '2017-03-12 13:19:08', '2017-03-12 17:19:08'])