from data.database import User
from util.names import parse_robot_username

def cleanup_old_robots(page_size=50):
  """ Deletes any robots that live under namespaces that no longer exist. """
  # Collect the robot accounts to delete.
  page_number = 1
  to_delete = []

  while True:
    found_bots = False
    for robot in list(User.select().where(User.robot == True).paginate(page_number, page_size)):
      found_bots = True
      namespace, _ = parse_robot_username(robot.username)
      try:
        User.get(username=namespace)
      except User.DoesNotExist:
        # Save the robot account for deletion.
        to_delete.append(robot)

    if not found_bots:
      break

    page_number = page_number + 1

  # Cleanup any robot accounts whose corresponding namespace doesn't exist.
  for robot in to_delete:
    robot.delete_instance(recursive=True, delete_nullable=True)