from util.config.validators import BaseValidator, ConfigValidationException
from data.users.keystone import get_keystone_users

class KeystoneValidator(BaseValidator):
  name = "keystone"

  @classmethod
  def validate(cls, validator_context):
    """ Validates the Keystone authentication system. """
    config = validator_context.config
    user = validator_context.user
    user_password = validator_context.user_password

    if config.get('AUTHENTICATION_TYPE', 'Database') != 'Keystone':
      return

    auth_url = config.get('KEYSTONE_AUTH_URL')
    auth_version = int(config.get('KEYSTONE_AUTH_VERSION', 2))
    admin_username = config.get('KEYSTONE_ADMIN_USERNAME')
    admin_password = config.get('KEYSTONE_ADMIN_PASSWORD')
    admin_tenant = config.get('KEYSTONE_ADMIN_TENANT')

    if not auth_url:
      raise ConfigValidationException('Missing authentication URL')

    if not admin_username:
      raise ConfigValidationException('Missing admin username')

    if not admin_password:
      raise ConfigValidationException('Missing admin password')

    if not admin_tenant:
      raise ConfigValidationException('Missing admin tenant')

    requires_email = config.get('FEATURE_MAILING', True)
    users = get_keystone_users(auth_version, auth_url, admin_username, admin_password, admin_tenant,
                               requires_email)

    # Verify that the superuser exists. If not, raise an exception.
    username = user.username
    (result, err_msg) = users.verify_credentials(username, user_password)
    if not result:
      msg = ('Verification of superuser %s failed: %s \n\nThe user either does not ' +
             'exist in the remote authentication system ' +
             'OR Keystone auth is misconfigured.') % (username, err_msg)
      raise ConfigValidationException(msg)