import logging
import time

import features

from app import app
from data.database import UseThenDisconnect
from data.model.repository import find_repository_with_garbage, get_random_gc_policy
from data.model.gc import garbage_collect_repo
from workers.worker import Worker

logger = logging.getLogger(__name__)

class GarbageCollectionWorker(Worker):
  def __init__(self):
    super(GarbageCollectionWorker, self).__init__()
    self.add_operation(self._garbage_collection_repos,
                       app.config.get('GARBAGE_COLLECTION_FREQUENCY', 30))

  def _garbage_collection_repos(self):
    """ Performs garbage collection on repositories. """
    with UseThenDisconnect(app.config):
      repository = find_repository_with_garbage(get_random_gc_policy())
      if repository is None:
        logger.debug('No repository with garbage found')
        return

      assert features.GARBAGE_COLLECTION

      logger.debug('Starting GC of repository #%s (%s)', repository.id, repository.name)
      garbage_collect_repo(repository)
      logger.debug('Finished GC of repository #%s (%s)', repository.id, repository.name)


if __name__ == "__main__":
  if not features.GARBAGE_COLLECTION:
    logger.debug('Garbage collection is disabled; skipping')
    while True:
      time.sleep(100000)

  if ((app.config.get('V3_UPGRADE_MODE') == 'production-transition') or 
      (app.config.get('V3_UPGRADE_MODE') == 'post-oci-rollout') or
      (app.config.get('V3_UPGRADE_MODE') == 'post-oci-roll-back-compat')):
    logger.debug('GC worker disabled for production transition; skipping')
    while True:
      time.sleep(100000)

  worker = GarbageCollectionWorker()
  worker.start()