text: # -*- coding: utf-8 -*-
  ###########################################################################
  # Copyright (c), The AiiDA team. All rights reserved.                     #
  # This file is part of the AiiDA code.                                    #
  #                                                                         #
  # The code is hosted on GitHub at https://github.com/aiidateam/aiida-core #
  # For further information on the license, see the LICENSE.txt file        #
  # For further information please visit http://www.aiida.net               #
  ###########################################################################
  # pylint: disable=cyclic-import
  """AiiDA manager for global settings"""
  
  import functools
  
  __all__ = ('get_manager', 'reset_manager')
  
  MANAGER = None
  
  
  class Manager:
      """
      Manager singleton to provide global versions of commonly used profile/settings related objects
      and methods to facilitate their construction.
  
      In AiiDA the settings of many objects are tied to options defined in the current profile.  This
      means that certain objects should be constructed in a way that depends on the profile.  Instead of
      having disparate parts of the code accessing the profile we put together here the profile and methods
      to create objects based on the current settings.
  
      It is also a useful place to put objects where there can be a single 'global' (per profile) instance.
  
      Future plans:
        * reset manager cache when loading a new profile
      """
  
      @staticmethod
      def get_profile():
          """Return the current loaded profile, if any
  
          :return: current loaded profile instance
          :rtype: :class:`~aiida.manage.configuration.profile.Profile` or None
          """
          from .configuration import get_profile
          return get_profile()
  
      def unload_backend(self):
          """Unload the current backend and its corresponding database environment."""
          manager = self.get_backend_manager()
          manager.reset_backend_environment()
          self._backend = None
  
      def _load_backend(self, schema_check=True):
          """Load the backend for the currently configured profile and return it.
  
          .. note:: this will reconstruct the `Backend` instance in `self._backend` so the preferred method to load the
              backend is to call `get_backend` which will create it only when not yet instantiated.
  
          :param schema_check: force a database schema check if the database environment has not yet been loaded
          :return: the database backend
          :rtype: :class:`aiida.orm.implementation.Backend`
          """
          from aiida.backends import BACKEND_DJANGO, BACKEND_SQLA
          from aiida.common import ConfigurationError, InvalidOperation
          from aiida.common.log import configure_logging
          from aiida.manage import configuration
  
          profile = self.get_profile()
  
          if profile is None:
              raise ConfigurationError(
                  'Could not determine the current profile. Consider loading a profile using `aiida.load_profile()`.'
              )
  
          if configuration.BACKEND_UUID is not None and configuration.BACKEND_UUID != profile.uuid:
              raise InvalidOperation('cannot load backend because backend of another profile is already loaded')
  
          # Do NOT reload the backend environment if already loaded, simply reload the backend instance after
          if configuration.BACKEND_UUID is None:
              manager = self.get_backend_manager()
              manager.load_backend_environment(profile, validate_schema=schema_check)
              configuration.BACKEND_UUID = profile.uuid
  
          backend_type = profile.database_backend
  
          # Can only import the backend classes after the backend has been loaded
          if backend_type == BACKEND_DJANGO:
              from aiida.orm.implementation.django.backend import DjangoBackend
              self._backend = DjangoBackend()
          elif backend_type == BACKEND_SQLA:
              from aiida.orm.implementation.sqlalchemy.backend import SqlaBackend
              self._backend = SqlaBackend()
  
          # Reconfigure the logging with `with_orm=True` to make sure that profile specific logging configuration options
          # are taken into account and the `DbLogHandler` is configured.
          configure_logging(with_orm=True)
  
          return self._backend
  
      @property
      def backend_loaded(self):
          """Return whether a database backend has been loaded.
  
          :return: boolean, True if database backend is currently loaded, False otherwise
          """
          return self._backend is not None
  
      def get_backend_manager(self):
          """Return the database backend manager.
  
          .. note:: this is not the actual backend, but a manager class that is necessary for database operations that
              go around the actual ORM. For example when the schema version has not yet been validated.
  
          :return: the database backend manager
          :rtype: :class:`aiida.backend.manager.BackendManager`
          """
          if self._backend_manager is None:
              from aiida.backends import get_backend_manager
              self._backend_manager = get_backend_manager(self.get_profile().database_backend)
  
          return self._backend_manager
  
      def get_backend(self):
          """Return the database backend
  
          :return: the database backend
          :rtype: :class:`aiida.orm.implementation.Backend`
          """
          if self._backend is None:
              self._load_backend()
  
          return self._backend
  
      def get_persister(self):
          """Return the persister
  
          :return: the current persister instance
          :rtype: :class:`plumpy.Persister`
          """
          from aiida.engine import persistence
  
          if self._persister is None:
              self._persister = persistence.AiiDAPersister()
  
          return self._persister
  
      def get_communicator(self):
          """Return the communicator
  
          :return: a global communicator instance
          :rtype: :class:`kiwipy.Communicator`
          """
          if self._communicator is None:
              self._communicator = self.create_communicator()
  
          return self._communicator
  
      def create_communicator(self, task_prefetch_count=None, with_orm=True):
          """Create a Communicator
  
          :param task_prefetch_count: optional specify how many tasks this communicator take simultaneously
          :param with_orm: if True, use ORM (de)serializers. If false, use json.
              This is used by verdi status to get a communicator without needing to load the dbenv.
  
          :return: the communicator instance
          :rtype: :class:`~kiwipy.rmq.communicator.RmqThreadCommunicator`
          """
          from aiida.manage.external import rmq
          import kiwipy.rmq
          profile = self.get_profile()
  
          if task_prefetch_count is None:
              task_prefetch_count = rmq._RMQ_TASK_PREFETCH_COUNT  # pylint: disable=protected-access
  
          url = rmq.get_rmq_url()
          prefix = profile.rmq_prefix
  
          # This needs to be here, because the verdi commands will call this function and when called in unit tests the
          # testing_mode cannot be set.
          testing_mode = profile.is_test_profile
  
          message_exchange = rmq.get_message_exchange_name(prefix)
          task_exchange = rmq.get_task_exchange_name(prefix)
          task_queue = rmq.get_launch_queue_name(prefix)
  
          if with_orm:
              from aiida.orm.utils import serialize
              encoder = functools.partial(serialize.serialize, encoding='utf-8')
              decoder = serialize.deserialize
          else:
              # used by verdi status to get a communicator without needing to load the dbenv
              from aiida.common import json
              encoder = functools.partial(json.dumps, encoding='utf-8')
              decoder = json.loads
  
          return kiwipy.rmq.RmqThreadCommunicator.connect(
              connection_params={'url': url},
              message_exchange=message_exchange,
              encoder=encoder,
              decoder=decoder,
              task_exchange=task_exchange,
              task_queue=task_queue,
              task_prefetch_count=task_prefetch_count,
              testing_mode=testing_mode,
          )
  
      def get_daemon_client(self):
          """Return the daemon client for the current profile.
  
          :return: the daemon client
          :rtype: :class:`aiida.daemon.client.DaemonClient`
          :raises aiida.common.MissingConfigurationError: if the configuration file cannot be found
          :raises aiida.common.ProfileConfigurationError: if the given profile does not exist
          """
          from aiida.engine.daemon.client import DaemonClient
  
          if self._daemon_client is None:
              self._daemon_client = DaemonClient(self.get_profile())
  
          return self._daemon_client
  
      def get_process_controller(self):
          """Return the process controller
  
          :return: the process controller instance
          :rtype: :class:`plumpy.RemoteProcessThreadController`
          """
          import plumpy
          if self._process_controller is None:
              self._process_controller = plumpy.RemoteProcessThreadController(self.get_communicator())
  
          return self._process_controller
  
      def get_runner(self):
          """Return a runner that is based on the current profile settings and can be used globally by the code.
  
          :return: the global runner
          :rtype: :class:`aiida.engine.runners.Runner`
          """
          if self._runner is None:
              self._runner = self.create_runner()
  
          return self._runner
  
      def set_runner(self, new_runner):
          """Set the currently used runner
  
          :param new_runner: the new runner to use
          :type new_runner: :class:`aiida.engine.runners.Runner`
          """
          if self._runner is not None:
              self._runner.close()
  
          self._runner = new_runner
  
      def create_runner(self, with_persistence=True, **kwargs):
          """Create and return a new runner
  
          :param with_persistence: create a runner with persistence enabled
          :type with_persistence: bool
          :return: a new runner instance
          :rtype: :class:`aiida.engine.runners.Runner`
          """
          from aiida.engine import runners
          from .configuration import get_config
  
          config = get_config()
          profile = self.get_profile()
          poll_interval = 0.0 if profile.is_test_profile else config.get_option('runner.poll.interval')
  
          settings = {'rmq_submit': False, 'poll_interval': poll_interval}
          settings.update(kwargs)
  
          if 'communicator' not in settings:
              # Only call get_communicator if we have to as it will lazily create
              settings['communicator'] = self.get_communicator()
  
          if with_persistence and 'persister' not in settings:
              settings['persister'] = self.get_persister()
  
          return runners.Runner(**settings)
  
      def create_daemon_runner(self, loop=None):
          """Create and return a new daemon runner.
  
          This is used by workers when the daemon is running and in testing.
  
          :param loop: the (optional) tornado event loop to use
          :type loop: :class:`tornado.ioloop.IOLoop`
          :return: a runner configured to work in the daemon configuration
          :rtype: :class:`aiida.engine.runners.Runner`
          """
          import plumpy
          from aiida.engine import persistence
          from aiida.manage.external import rmq
          runner = self.create_runner(rmq_submit=True, loop=loop)
          runner_loop = runner.loop
  
          # Listen for incoming launch requests
          task_receiver = rmq.ProcessLauncher(
              loop=runner_loop,
              persister=self.get_persister(),
              load_context=plumpy.LoadSaveContext(runner=runner),
              loader=persistence.get_object_loader()
          )
  
          def callback(*args, **kwargs):
              return plumpy.create_task(functools.partial(task_receiver, *args, **kwargs), loop=runner_loop)
  
          runner.communicator.add_task_subscriber(callback)
  
          return runner
  
      def close(self):
          """Reset the global settings entirely and release any global objects."""
          if self._communicator is not None:
              self._communicator.stop()
          if self._runner is not None:
              self._runner.stop()
  
          self._backend = None
          self._backend_manager = None
          self._config = None
          self._profile = None
          self._communicator = None
          self._daemon_client = None
          self._process_controller = None
          self._persister = None
          self._runner = None
  
      def __init__(self):
          super().__init__()
          self._backend = None  # type: aiida.orm.implementation.Backend
          self._backend_manager = None  # type: aiida.backend.manager.BackendManager
          self._config = None  # type: aiida.manage.configuration.config.Config
          self._daemon_client = None  # type: aiida.daemon.client.DaemonClient
          self._profile = None  # type: aiida.manage.configuration.profile.Profile
          self._communicator = None  # type: kiwipy.rmq.RmqThreadCommunicator
          self._process_controller = None  # type: plumpy.RemoteProcessThreadController
          self._persister = None  # type: aiida.engine.persistence.AiiDAPersister
          self._runner = None  # type: aiida.engine.runners.Runner
  
  
  def get_manager():
      global MANAGER  # pylint: disable=global-statement
      if MANAGER is None:
          MANAGER = Manager()
      return MANAGER
  
  
  def reset_manager():
      global MANAGER  # pylint: disable=global-statement
      if MANAGER is not None:
          MANAGER.close()
          MANAGER = None
  