from app import app
from storage import get_storage_driver
from util.config.validators import BaseValidator, ConfigValidationException

class StorageValidator(BaseValidator):
  name = "registry-storage"

  @classmethod
  def validate(cls, config, user, user_password):
    """ Validates registry storage. """
    replication_enabled = config.get('FEATURE_STORAGE_REPLICATION', False)

    providers = _get_storage_providers(config).items()
    if not providers:
      raise ConfigValidationException('Storage configuration required')

    for name, (storage_type, driver) in providers:
      try:
        if replication_enabled and storage_type == 'LocalStorage':
          raise ConfigValidationException('Locally mounted directory not supported ' +
                                          'with storage replication')

        # Run validation on the driver.
        driver.validate(app.config['HTTPCLIENT'])

        # Run setup on the driver if the read/write succeeded.
        driver.setup()
      except Exception as ex:
        msg = str(ex).strip()
        raise ConfigValidationException('Invalid storage configuration: %s: %s' % (name, msg))


def _get_storage_providers(config):
  storage_config = config.get('DISTRIBUTED_STORAGE_CONFIG', {})
  drivers = {}

  try:
    for name, parameters in storage_config.items():
      drivers[name] = (parameters[0], get_storage_driver(None, None, None, parameters))
  except TypeError:
    raise ConfigValidationException('Missing required parameter(s) for storage %s' % name)

  return drivers