import os
import base64

from backports.tempfile import TemporaryDirectory

from config_app.config_util.config.fileprovider import FileConfigProvider
from config_app.config_util.k8saccessor import KubernetesAccessorSingleton
from util.config.validator import EXTRA_CA_DIRECTORY, EXTRA_CA_DIRECTORY_PREFIX



class TransientDirectoryProvider(FileConfigProvider):
  """ Implementation of the config provider that reads and writes the data
      from/to the file system, only using temporary directories,
      deleting old dirs and creating new ones as requested.
  """

  def __init__(self, config_volume, yaml_filename, py_filename):
    # Create a temp directory that will be cleaned up when we change the config path
    # This should ensure we have no "pollution" of different configs:
    # no uploaded config should ever affect subsequent config modifications/creations
    temp_dir = TemporaryDirectory()
    self.temp_dir = temp_dir
    super(TransientDirectoryProvider, self).__init__(temp_dir.name, yaml_filename, py_filename)

  @property
  def provider_id(self):
    return 'transient'

  def new_config_dir(self):
    """
    Update the path with a new temporary directory, deleting the old one in the process
    """
    self.temp_dir.cleanup()
    temp_dir = TemporaryDirectory()

    self.config_volume = temp_dir.name
    self.temp_dir = temp_dir
    self.yaml_path = os.path.join(temp_dir.name, self.yaml_filename)

  def get_config_dir_path(self):
    return self.config_volume

  def save_configuration_to_kubernetes(self):
    data = {}

    # Kubernetes secrets don't have sub-directories, so for the extra_ca_certs dir
    # we have to put the extra certs in with a prefix, and then one of our init scripts
    # (02_get_kube_certs.sh) will expand the prefixed certs into the equivalent directory
    # so that they'll be installed correctly on startup by the certs_install script
    certs_dir = os.path.join(self.config_volume, EXTRA_CA_DIRECTORY)
    if os.path.exists(certs_dir):
      for extra_cert in os.listdir(certs_dir):
        with open(os.path.join(certs_dir, extra_cert)) as f:
          data[EXTRA_CA_DIRECTORY_PREFIX + extra_cert] = base64.b64encode(f.read())


    for name in os.listdir(self.config_volume):
      file_path = os.path.join(self.config_volume, name)
      if not os.path.isdir(file_path):
        with open(file_path) as f:
          data[name] = base64.b64encode(f.read())

    KubernetesAccessorSingleton.get_instance().replace_qe_secret(data)

    return 200