text: # -*- coding: utf-8 -*- {{{
  # vim: set fenc=utf-8 ft=python sw=4 ts=4 sts=4 et:
  #
  # Copyright 2019, Battelle Memorial Institute.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  # http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  #
  # This material was prepared as an account of work sponsored by an agency of
  # the United States Government. Neither the United States Government nor the
  # United States Department of Energy, nor Battelle, nor any of their
  # employees, nor any jurisdiction or organization that has cooperated in the
  # development of these materials, makes any warranty, express or
  # implied, or assumes any legal liability or responsibility for the accuracy,
  # completeness, or usefulness or any information, apparatus, product,
  # software, or process disclosed, or represents that its use would not infringe
  # privately owned rights. Reference herein to any specific commercial product,
  # process, or service by trade name, trademark, manufacturer, or otherwise
  # does not necessarily constitute or imply its endorsement, recommendation, or
  # favoring by the United States Government or any agency thereof, or
  # Battelle Memorial Institute. The views and opinions of authors expressed
  # herein do not necessarily state or reflect those of the
  # United States Government or any agency thereof.
  #
  # PACIFIC NORTHWEST NATIONAL LABORATORY operated by
  # BATTELLE for the UNITED STATES DEPARTMENT OF ENERGY
  # under Contract DE-AC05-76RL01830
  # }}}
  
  
  
  import inspect
  import logging
  import os
  import sys
  import traceback
  import weakref
  import re
  
  import gevent.local
  from gevent.event import AsyncResult
  from volttron.platform import jsonapi
  from volttron.platform.agent.utils import get_messagebus
  
  from .base import SubsystemBase
  from ..errors import VIPError
  from ..results import counter, ResultsDictionary
  from ..decorators import annotate, annotations, dualmethod, spawn
  from .... import jsonrpc
  from volttron.platform.vip.socket import Message
  
  from zmq import Frame, NOBLOCK, ZMQError, EINVAL, EHOSTUNREACH
  from zmq.green import ENOTSOCK
  
  
  __all__ = ['RPC']
  
  
  _ROOT_PACKAGE_PATH = os.path.dirname(
      __import__(__name__.split('.', 1)[0]).__path__[-1]) + os.sep
  
  _log = logging.getLogger(__name__)
  
  
  def _isregex(obj):
      return obj is not None and isinstance(obj, str) and len(obj) > 1 and obj[0] == obj[-1] == '/'
  
  class Dispatcher(jsonrpc.Dispatcher):
      def __init__(self, methods, local):
          super(Dispatcher, self).__init__()
          self.methods = methods
          self.local = local
          self._results = ResultsDictionary()
  
      def serialize(self, json_obj):
          return jsonapi.dumps(json_obj)
  
      def deserialize(self, json_string):
          return jsonapi.loads(json_string)
  
      def batch_call(self, requests):
          methods = []
          results = []
          for notify, method, args, kwargs in requests:
              if notify:
                  ident = None
              else:
                  result = next(self._results)
                  ident = result.ident
                  results.append(result)
              methods.append((ident, method, args, kwargs))
          return super(Dispatcher, self).batch_call(methods), results
  
      def call(self, method, args=None, kwargs=None):
          # pylint: disable=arguments-differ
          result = next(self._results)
          return super(Dispatcher, self).call(
              result.ident, method, args, kwargs), result
  
      def result(self, response, ident, value, context=None):
          try:
              result = self._results.pop(ident)
          except KeyError:
              return
          result.set(value)
  
      def error(self, response, ident, code, message, data=None, context=None):
          try:
              result = self._results.pop(ident)
          except KeyError:
              return
          result.set_exception(jsonrpc.exception_from_json(code, message, data))
  
      def exception(self, response, ident, message, context=None):
          # XXX: Should probably wrap exception in RPC specific error
          #      rather than re-raising.
          exc_type, exc, exc_tb = sys.exc_info()   # pylint: disable=unused-variable
          try:
              result = self._results.pop(ident)
          except KeyError:
              return
          result.set_exception(exc)
  
      def method(self, request, ident, name, args, kwargs,
                 batch=None, context=None):
          if kwargs:
              try:
                  args, kwargs = kwargs['*args'], kwargs['**kwargs']
              except KeyError:
                  pass
          try:
              method = self.methods[name]
          except KeyError:
              if name == 'inspect':
                  return {'methods': list(self.methods)}
              elif name.endswith('.inspect'):
                  try:
                      method = self.methods[name[:-8]]
                  except KeyError:
                      pass
                  else:
                      return self._inspect(method)
              raise NotImplementedError(name)
          local = self.local
          local.vip_message = context
          local.request = request
          local.batch = batch
          try:
              return method(*args, **kwargs)
          except Exception as exc:   # pylint: disable=broad-except
              exc_tb = traceback.format_exc()
              _log.error('unhandled exception in JSON-RPC method %r: \n%s',
                         name, exc_tb)
              if getattr(method, 'traceback', True):
                  exc.exc_info = {'exc_tb': exc_tb}
              raise
          finally:
              del local.vip_message
              del local.request
              del local.batch
  
      @staticmethod
      def _inspect(method):
          response = {'params': {}}
          signature = inspect.signature(method)
          for p in signature.parameters.values():
              response['params'][p.name] = {
                      'kind': p.kind.name
              }
              if p.default is not inspect.Parameter.empty:
                  response['params'][p.name]['default'] = p.default
              if p.annotation is not inspect.Parameter.empty:
                  annotation = p.annotation.__name__ if type(p.annotation) is type else str(p.annotation)
                  response['params'][p.name]['annotation'] = annotation
          doc = inspect.getdoc(method)
          if doc:
              response['doc'] = doc
          try:
              source = inspect.getsourcefile(method)
              cut = len(os.path.commonprefix([_ROOT_PACKAGE_PATH, source]))
              source = source[cut:]
              lineno = inspect.getsourcelines(method)[1]
          except Exception:
              pass
          else:
              response['source'] = {
                  'file': source,
                  'line_number': lineno
              }
          ret = signature.return_annotation
          if ret is not inspect.Signature.empty:
              response['return'] = ret.__name__ if type(ret) is type else str(ret)
          return response
  
  
  class RPC(SubsystemBase):
      def __init__(self, core, owner, peerlist_subsys):
          self.core = weakref.ref(core)
          self._owner = owner
          self.context = None
          self._exports = {}
          self._dispatcher = None
          self._counter = counter()
          self._outstanding = weakref.WeakValueDictionary()
          core.register('RPC', self._handle_subsystem, self._handle_error)
          core.register('external_rpc', self._handle_external_rpc_subsystem, self._handle_error)
          self._isconnected = True
          self._message_bus = self.core().messagebus
          self.peerlist_subsystem = peerlist_subsys
          self.peer_list = {}
  
          def export(member):   # pylint: disable=redefined-outer-name
              for name in annotations(member, set, 'rpc.exports'):
                  self._exports[name] = member
          inspect.getmembers(owner, export)
  
          def setup(sender, **kwargs):
              # pylint: disable=unused-argument
              self.context = gevent.local.local()
              self._dispatcher = Dispatcher(self._exports, self.context)
          core.onsetup.connect(setup, self)
          core.ondisconnected.connect(self._disconnected)
          core.onconnected.connect(self._connected)
          self._iterate_exports()
  
      def _connected(self, sender, **kwargs):
          self._isconnected =True
          # Registering to 'onadd' and 'ondrop' signals to get notified whenever new peer is added/removed
          self.peerlist_subsystem.onadd.connect(self._add_new_peer)
          self.peerlist_subsystem.ondrop.connect(self._drop_new_peer)
  
      def _disconnected(self, sender, **kwargs):
          self._isconnected = False
  
      def _add_new_peer(self, sender, **kwargs):
          try:
              peer = kwargs.pop('peer')
              message_bus = kwargs.pop('message_bus')
              self.peer_list[peer] = message_bus
          except KeyError:
              pass
  
      def _drop_new_peer(self, sender, **kwargs):
          try:
              peer = kwargs.pop('peer')
              self.peer_list.pop(peer)
          except KeyError:
              pass
  
      def _iterate_exports(self):
          '''Iterates over exported methods and adds authorization checks
          as necessary
          '''
          for method_name in self._exports:
              method = self._exports[method_name]
              caps = annotations(method, set, 'rpc.allow_capabilities')
              if caps:
                  self._exports[method_name] = self._add_auth_check(method, caps)
  
      def _add_auth_check(self, method, required_caps):
          '''Adds an authorization check to verify the calling agent has the
          required capabilities.
          '''
          def checked_method(*args, **kwargs):
              user = str(self.context.vip_message.user)
              if self._message_bus == "rmq":
                  # When we address issue #2107 external platform user should
                  # have instance name also included in username.
                  user = user.split(".")[1]
              _log.debug("Current user in checked_method is {}".format(user))
              user_capabilites = self._owner.vip.auth.get_capabilities(user)
              _log.debug("**user caps is: {}".format(user_capabilites))
              if user_capabilites:
                  user_capabilities_names = set(user_capabilites.keys())
              else:
                  user_capabilities_names = set()
  
              _log.debug("Required caps is : {}".format(required_caps))
              _log.debug("user capability names: {}".format(user_capabilities_names))
              if not required_caps.issubset(user_capabilities_names):
                  msg = ('method "{}" requires capabilities {}, but capability {} was'
                         ' provided for user {}').format(method.__name__, required_caps, user_capabilites, user)
                  raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED, msg)
              else:
                  # Now check if args passed to method are the ones allowed.
  
                  for cap_name, param_dict in user_capabilites.items():
                      if param_dict and required_caps and cap_name in required_caps:
                          # if the method has required capabilities and
                          # if the user capability has argument restrictions, check if the args passed to method
                          # match the requirement
                          _log.debug("args = {} kwargs= {}".format(args, kwargs))
                          args_dict = inspect.getcallargs(method, *args, **kwargs)
                          _log.debug("dict = {}".format(args_dict))
                          _log.debug("name= {} parameters allowed={}".format(cap_name, param_dict))
                          for name, value in param_dict.items():
                              _log.debug("name= {} value={}".format(name, value))
                              if name not in args_dict:
                                  raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED,
                                                                    "User {} capability is not defined "
                                                                    "properly. method {} does not have "
                                                                    "a parameter {}".format(user, method.__name__, name))
                              if _isregex(value):
                                  regex = re.compile('^' + value[1:-1] + '$')
                                  if not regex.match(args_dict[name]):
                                      raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED,
                                                                        "User {} can call method {} only "
                                                                        "with {} matching pattern {} but called with "
                                                                        "{}={}".format(user, method.__name__, name, value,
                                                                                       name, args_dict[name]))
                              elif args_dict[name] != value:
                                  raise jsonrpc.exception_from_json(jsonrpc.UNAUTHORIZED,
                                                                    "User {} can call method {} only "
                                                                    "with {}={} but called with "
                                                                    "{}={}".format(user, method.__name__, name, value,
                                                                                   name, args_dict[name]))
  
              return method(*args, **kwargs)
          return checked_method
  
      @spawn
      def _handle_external_rpc_subsystem(self, message):
          ret_msg = dict()
          #_log.debug("EXT_RPC subsystem handler IN message {0}".format(message))
          op = message.args[0]
          rpc_msg = message.args[1] #jsonapi.loads(message.args[1])
          try:
              #_log.debug("EXT_RPC subsystem handler IN message {0}, {1}".format(message.peer, rpc_msg))
              method_args = rpc_msg['args']
              #message.args = [method_args]
              message.args = method_args
              for idx, msg in enumerate(message.args):
                  if isinstance(msg, str):
                      message.args[idx] = jsonapi.loads(msg)
              dispatch = self._dispatcher.dispatch
              #_log.debug("External RPC IN message args {}".format(message))
  
              responses = [response for response in (
                  dispatch(msg, message) for msg in message.args) if response]
              #_log.debug("External RPC Responses {}".format(responses))
              if responses:
                  message.user = ''
                  try:
                      message.peer = ''
                      message.subsystem = 'external_rpc'
                      frames = []
                      op = 'send_platform'
                      frames.append(op)
                      msg = jsonapi.dumps(dict(to_platform=rpc_msg['from_platform'],
                                               to_peer=rpc_msg['from_peer'],
                                               from_platform=rpc_msg['to_platform'],
                                               from_peer=rpc_msg['to_peer'], args=responses))
                      frames.append(msg)
                  except KeyError:
                      _log.error("External RPC message did not contain proper message format")
                  message.args = jsonapi.dumps(ret_msg)
                  #_log.debug("EXT_RPC subsystem handler OUT message {}".format(message))
                  try:
                      self.core().connection.send_vip(peer='',
                                                      subsystem='external_rpc',
                                                      args=frames,
                                                      msg_id=message.id,
                                                      user=message.user,
                                                      copy=False)
                  except ZMQError as ex:
                      _log.error("ZMQ error: {}".format(ex))
                      pass
          except KeyError:
              pass
  
      @spawn
      def _handle_subsystem(self, message):
          dispatch = self._dispatcher.dispatch
  
          if self._message_bus == "rmq":
              for idx, msg in enumerate(message.args):
                  if not isinstance(msg, dict):
                      message.args[idx] = jsonapi.loads(msg)
  
              responses = [response for response in (
                  dispatch(msg, message) for msg in message.args) if response]
          else:
              responses = [response for response in (
                  dispatch(msg, message) for msg in message.args) if response]
          if responses:
              message.user = ''
              message.args = responses
              try:
                  if self._isconnected:
                      if self._message_bus == 'zmq':
                          self.core().connection.send_vip_object(message, copy=False)
                      else:
                          # Agent is running on RMQ message bus.
                          # Adding backward compatibility support for ZMQ. Check if the peer
                          # is running on ZMQ bus. If yes, send RPC message to proxy router
                          # agent to forward using ZMQ message bus connection
                          try:
                              msg_bus = self.peer_list[message.peer]
                          except KeyError:
                              msg_bus = self._message_bus
                          if msg_bus == 'zmq':
                              # If peer connected to ZMQ bus, send via proxy router agent
                              self.core().connection.send_vip_object_via_proxy(message)
                          else:
                              self.core().connection.send_vip_object(message, copy=False)
              except ZMQError as exc:
                  if exc.errno == ENOTSOCK:
                      _log.debug("Socket send on non socket {}".format(self.core().identity))
  
      def _handle_error(self, sender, message, error, **kwargs):
          result = self._outstanding.pop(message.id, None)
          if isinstance(result, AsyncResult):
              result.set_exception(error)
          elif result:
              for result in result:
                  result.set_exception(error)
  
      @dualmethod
      def export(self, method, name=None):
          self._exports[name or method.__name__] = method
          return method
  
      @export.classmethod
      def export(cls, name=None):   # pylint: disable=no-self-argument
          if name is not None and not isinstance(name, str):
              method, name = name, name.__name__
              annotate(method, set, 'rpc.exports', name)
              return method
  
          def decorate(method):
              annotate(method, set, 'rpc.exports', name)
              return method
          return decorate
  
      def batch(self, peer, requests):
          request, results = self._dispatcher.batch_call(requests)
          if results:
              items = weakref.WeakSet(results)
              ident = '%s.%s' % (next(self._counter), id(items))
              for result in results:
                  result._weak_set = items   # pylint: disable=protected-access
              self._outstanding[ident] = items
          else:
              ident = ''
          if request:
              if self._isconnected:
                  try:
                      self.core().connection.send_vip(peer, 'RPC', [request], msg_id=ident)
                  except ZMQError as exc:
                      if exc.errno == ENOTSOCK:
                          _log.debug("Socket send on non socket {}".format(self.core().identity))
          return results or None
  
      def call(self, peer, method, *args, **kwargs):
          platform = kwargs.pop('external_platform', '')
          request, result = self._dispatcher.call(method, args, kwargs)
          ident = f'{next(self._counter)}.{hash(result)}'
          self._outstanding[ident] = result
          subsystem = None
          frames = []
  
          if not self._isconnected:
              return
  
          if self._message_bus == 'zmq':
              if platform == '':#local platform
                  subsystem = 'RPC'
                  frames.append(request)
              else:
                  frames = []
                  op = 'send_platform'
                  subsystem = 'external_rpc'
                  frames.append(op)
                  msg = dict(to_platform=platform, to_peer=peer,
                             from_platform='', from_peer='', args=[request])
                  frames.append(msg)
                  peer = ''
  
              try:
                  # _log.debug("peer: {0}, subsytem: {1}, args:{2}, id: {3}".format(peer, subsystem,
                  #                                                                 args, id))
                  self.core().connection.send_vip(peer,
                                                  subsystem,
                                                  args=frames,
                                                  msg_id=ident)
              except ZMQError as exc:
                  if exc.errno == ENOTSOCK:
                      _log.debug("Socket send on non socket {}".format(self.core().identity))
              # _log.debug("RPC subsystem: External platform RPC msg: {}".format(frames))
          else:
              # Agent running on RMQ message bus.
              # Adding backward compatibility support for ZMQ. Check if peer
              # is running on ZMQ bus. If yes, send RPC message to proxy router agent to
              # forward over ZMQ message bus connection
              try:
                  peer_msg_bus = self.peer_list[peer]
              except KeyError:
                  peer_msg_bus = self._message_bus
              if peer_msg_bus == 'zmq':
                  # peer connected to ZMQ bus, send via proxy router agent
                  self.core().connection.send_via_proxy(peer, 'RPC', msg_id=ident, args=[request])
              else:
                  self.core().connection.send_vip(peer,
                                                  'RPC',
                                                  args=[request],
                                                  msg_id=ident,
                                                  platform=platform)
  
          return result
  
      __call__ = call
  
      def notify(self, peer, method, *args, **kwargs):
          platform = kwargs.pop('external_platform', '')
          request = self._dispatcher.notify(method, args, kwargs)
          frames = []
          if not self._isconnected:
              return
  
          if self._message_bus == 'zmq':
              subsystem = None
              if platform == '':
                  subsystem = 'RPC'
                  frames.append(request)
              else:
                  op = 'send_platform'
                  subsystem = 'external_rpc'
                  frames.append(op)
                  msg = dict(to_platform=platform, to_peer=peer,
                             from_platform='', from_peer='', args=[request])
                  frames.append(msg)
                  peer = ''
  
              try:
                  # _log.debug("peer: {0}, subsytem: {1}, args:{2}".format(peer, subsystem,
                  #                                                             frames))
                  self.core().connection.send_vip(peer,
                                                  subsystem,
                                                  args=frames)
              except ZMQError as exc:
                  if exc.errno == ENOTSOCK:
                      _log.debug("Socket send on non socket {}".format(self.core().identity))
          else:
              # Agent running on RMQ message bus.
              # Adding backward compatibility support for ZMQ. Check if peer
              # is running on ZMQ bus. If yes, send RPC message to proxy router agent to
              # forward over ZMQ message bus connection
              try:
                  peer_msg_bus = self.peer_list[peer]
              except KeyError:
                  #self.peer_list = self.peerlist_subsystem.list_with_messagebus().get(2)
                  #_log.debug("PEERS: {}".format(self.peer_list))
                  peer_msg_bus = self._message_bus
              if peer_msg_bus == 'zmq':
                  # peer connected to ZMQ bus, send via proxy router agent
                  self.core().connection.send_via_proxy(peer,
                                                        'RPC',
                                                        args=[request])
              else:
                  self.core().connection.send_vip(peer,
                                                  'RPC',
                                                  args=[request],
                                                  platform=platform)
  
      @dualmethod
      def allow(self, method, capabilities):
          if isinstance(capabilities, str):
              cap = set([capabilities])
          else:
              cap = set(capabilities)
          self._exports[method.__name__] = self._add_auth_check(method, cap)
  
      @allow.classmethod
      def allow(cls, capabilities):
          """
          Decorator specifies required agent capabilities to call a method.
  
          This is designed to be used with the export decorator:
  
          .. code-block:: python
  
              @RPC.export
              @RPC.allow('can_read_status')
              def get_status():
                  ...
  
          Multiple capabilities can be provided in a list:
          .. code-block:: python
  
              @RPC.allow(['can_read_status', 'can_call_my_methods'])
  
          """
          def decorate(method):
              if isinstance(capabilities, str):
                  annotate(method, set, 'rpc.allow_capabilities', capabilities)
              else:
                  for cap in capabilities:
                      annotate(method, set, 'rpc.allow_capabilities', cap)
              return method
          return decorate
  