import logging

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

logger = logging.getLogger(__name__)
logger.setLevel(logging.INFO)


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 = []
  encountered_namespaces = {}

  while True:
    found_bots = False
    for robot in list(User.select().where(User.robot == True).paginate(page_number, page_size)):
      found_bots = True
      logger.info("Checking robot %s (page %s)", robot.username, page_number)
      parsed = parse_robot_username(robot.username)
      if parsed is None:
        continue

      namespace, _ = parsed
      if namespace in encountered_namespaces:
        if not encountered_namespaces[namespace]:
          logger.info('Marking %s to be deleted', robot.username)
          to_delete.append(robot)
      else:
        try:
          User.get(username=namespace)
          encountered_namespaces[namespace] = True
        except User.DoesNotExist:
          # Save the robot account for deletion.
          logger.info('Marking %s to be deleted', robot.username)
          to_delete.append(robot)
          encountered_namespaces[namespace] = False

    if not found_bots:
      break

    page_number = page_number + 1

  # Cleanup any robot accounts whose corresponding namespace doesn't exist.
  logger.info('Found %s robots to delete', len(to_delete))
  for index, robot in enumerate(to_delete):
    logger.info('Deleting robot %s of %s (%s)', index, len(to_delete), robot.username)
    robot.delete_instance(recursive=True, delete_nullable=True)