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# Source code for astropy.samp.client

    # Licensed under a 3-clause BSD style license - see LICENSE.rst

    import copy
    import os
    import select
    import socket
    import threading
    import warnings
    from urllib.parse import urlunparse

    from .constants import SAMP_STATUS_OK, SAMP_STATUS_WARNING
    from .errors import SAMPClientError, SAMPWarning
    from .hub import SAMPHubServer
    from .standard_profile import ThreadingXMLRPCServer
    from .utils import get_num_args, internet_on

    __all__ = ["SAMPClient"]

    class SAMPClient:
        """
        Utility class which provides facilities to create and manage a SAMP
        compliant XML-RPC server that acts as SAMP callable client application.

        Parameters
        ----------
        hub : :class:`~astropy.samp.SAMPHubProxy`
            An instance of :class:`~astropy.samp.SAMPHubProxy` to be
            used for messaging with the SAMP Hub.

        name : str, optional
            Client name (corresponding to ``samp.name`` metadata keyword).

        description : str, optional
            Client description (corresponding to ``samp.description.text`` metadata
            keyword).

        metadata : dict, optional
            Client application metadata in the standard SAMP format.

        addr : str, optional
            Listening address (or IP). This defaults to 127.0.0.1 if the internet
            is not reachable, otherwise it defaults to the host name.

        port : int, optional
            Listening XML-RPC server socket port. If left set to 0 (the default),
            the operating system will select a free port.

        callable : bool, optional
            Whether the client can receive calls and notifications. If set to
            `False`, then the client can send notifications and calls, but can not
            receive any.
        """

        # TODO: define what is meant by callable

        def __init__(
            self,
            hub,
            name=None,
            description=None,
            metadata=None,
            addr=None,
            port=0,
            callable=True,
        ):
            # GENERAL
            self._is_running = False
            self._is_registered = False

            if metadata is None:
                metadata = {}

            if name is not None:
                metadata["samp.name"] = name

            if description is not None:
                metadata["samp.description.text"] = description

            self._metadata = metadata

            self._addr = addr
            self._port = port
            self._xmlrpcAddr = None
            self._callable = callable

            # HUB INTERACTION
            self.client = None
            self._public_id = None
            self._private_key = None
            self._hub_id = None
            self._notification_bindings = {}
            self._call_bindings = {
                "samp.app.ping": [self._ping, {}],
                "client.env.get": [self._client_env_get, {}],
            }
            self._response_bindings = {}

            self._host_name = "127.0.0.1"
            if internet_on():
                try:
                    self._host_name = socket.getfqdn()
                    socket.getaddrinfo(self._addr or self._host_name, self._port or 0)
                except OSError:
                    self._host_name = "127.0.0.1"

            self.hub = hub

            if self._callable:
                self._thread = threading.Thread(target=self._serve_forever)
                self._thread.daemon = True

                self.client = ThreadingXMLRPCServer(
                    (self._addr or self._host_name, self._port),
                    logRequests=False,
                    allow_none=True,
                )

                self.client.register_introspection_functions()
                self.client.register_function(
                    self.receive_notification, "samp.client.receiveNotification"
                )
                self.client.register_function(self.receive_call, "samp.client.receiveCall")
                self.client.register_function(
                    self.receive_response, "samp.client.receiveResponse"
                )

                # If the port was set to zero, then the operating system has
                # selected a free port. We now check what this port number is.
                if self._port == 0:
                    self._port = self.client.socket.getsockname()[1]

                protocol = "http"

                self._xmlrpcAddr = urlunparse(
                    (
                        protocol,
                        f"{self._addr or self._host_name}:{self._port}",
                        "",
                        "",
                        "",
                        "",
                    )
                )

        def start(self):
            """
            Start the client in a separate thread (non-blocking).

            This only has an effect if ``callable`` was set to `True` when
            initializing the client.
            """
            if self._callable:
                self._is_running = True
                self._run_client()

        def stop(self, timeout=10.0):
            """
            Stop the client.

            Parameters
            ----------
            timeout : float
                Timeout after which to give up if the client cannot be cleanly
                shut down.
            """
            # Setting _is_running to False causes the loop in _serve_forever to
            # exit. The thread should then stop running. We wait for the thread to
            # terminate until the timeout, then we continue anyway.
            self._is_running = False
            if self._callable and self._thread.is_alive():
                self._thread.join(timeout)
            if self._thread.is_alive():
                raise SAMPClientError(
                    f"Client was not shut down successfully (timeout={timeout}s)"
                )

        @property
        def is_running(self):
            """
            Whether the client is currently running.
            """
            return self._is_running

        @property
        def is_registered(self):
            """
            Whether the client is currently registered.
            """
            return self._is_registered

        def _run_client(self):
            if self._callable:
                self._thread.start()

        def _serve_forever(self):
            while self._is_running:
                try:
                    read_ready = select.select([self.client.socket], [], [], 0.1)[0]
                except OSError as exc:
                    warnings.warn(
                        f"Call to select in SAMPClient failed: {exc}", SAMPWarning
                    )
                else:
                    if read_ready:
                        self.client.handle_request()

            self.client.server_close()

        def _ping(self, private_key, sender_id, msg_id, msg_mtype, msg_params, message):
            reply = {"samp.status": SAMP_STATUS_OK, "samp.result": {}}

            self.hub.reply(private_key, msg_id, reply)

        def _client_env_get(
            self, private_key, sender_id, msg_id, msg_mtype, msg_params, message
        ):
            if msg_params["name"] in os.environ:
                reply = {
                    "samp.status": SAMP_STATUS_OK,
                    "samp.result": {"value": os.environ[msg_params["name"]]},
                }
            else:
                reply = {
                    "samp.status": SAMP_STATUS_WARNING,
                    "samp.result": {"value": ""},
                    "samp.error": {"samp.errortxt": "Environment variable not defined."},
                }

            self.hub.reply(private_key, msg_id, reply)

        def _handle_notification(self, private_key, sender_id, message):
            if private_key == self.get_private_key() and "samp.mtype" in message:
                msg_mtype = message["samp.mtype"]
                del message["samp.mtype"]
                msg_params = message["samp.params"]
                del message["samp.params"]

                msubs = SAMPHubServer.get_mtype_subtypes(msg_mtype)
                for mtype in msubs:
                    if mtype in self._notification_bindings:
                        bound_func = self._notification_bindings[mtype][0]
                        if get_num_args(bound_func) == 5:
                            bound_func(
                                private_key, sender_id, msg_mtype, msg_params, message
                            )
                        else:
                            bound_func(
                                private_key, sender_id, None, msg_mtype, msg_params, message
                            )

            return ""

        def receive_notification(self, private_key, sender_id, message):
            """
            Standard callable client ``receive_notification`` method.

            This method is automatically handled when the
            :meth:`~astropy.samp.client.SAMPClient.bind_receive_notification`
            method is used to bind distinct operations to MTypes. In case of a
            customized callable client implementation that inherits from the
            :class:`~astropy.samp.SAMPClient` class this method should be
            overwritten.

            .. note:: When overwritten, this method must always return
                      a string result (even empty).

            Parameters
            ----------
            private_key : str
                Client private key.

            sender_id : str
                Sender public ID.

            message : dict
                Received message.

            Returns
            -------
            confirmation : str
                Any confirmation string.
            """
            return self._handle_notification(private_key, sender_id, message)

        def _handle_call(self, private_key, sender_id, msg_id, message):
            if private_key == self.get_private_key() and "samp.mtype" in message:
                msg_mtype = message["samp.mtype"]
                del message["samp.mtype"]
                msg_params = message["samp.params"]
                del message["samp.params"]

                msubs = SAMPHubServer.get_mtype_subtypes(msg_mtype)

                for mtype in msubs:
                    if mtype in self._call_bindings:
                        self._call_bindings[mtype][0](
                            private_key, sender_id, msg_id, msg_mtype, msg_params, message
                        )

            return ""

        def receive_call(self, private_key, sender_id, msg_id, message):
            """
            Standard callable client ``receive_call`` method.

            This method is automatically handled when the
            :meth:`~astropy.samp.client.SAMPClient.bind_receive_call` method is
            used to bind distinct operations to MTypes. In case of a customized
            callable client implementation that inherits from the
            :class:`~astropy.samp.SAMPClient` class this method should be
            overwritten.

            .. note:: When overwritten, this method must always return
                      a string result (even empty).

            Parameters
            ----------
            private_key : str
                Client private key.

            sender_id : str
                Sender public ID.

            msg_id : str
                Message ID received.

            message : dict
                Received message.

            Returns
            -------
            confirmation : str
                Any confirmation string.
            """
            return self._handle_call(private_key, sender_id, msg_id, message)

        def _handle_response(self, private_key, responder_id, msg_tag, response):
            if private_key == self.get_private_key() and msg_tag in self._response_bindings:
                self._response_bindings[msg_tag](
                    private_key, responder_id, msg_tag, response
                )
            return ""

        def receive_response(self, private_key, responder_id, msg_tag, response):
            """
            Standard callable client ``receive_response`` method.

            This method is automatically handled when the
            :meth:`~astropy.samp.client.SAMPClient.bind_receive_response` method
            is used to bind distinct operations to MTypes. In case of a customized
            callable client implementation that inherits from the
            :class:`~astropy.samp.SAMPClient` class this method should be
            overwritten.

            .. note:: When overwritten, this method must always return
                      a string result (even empty).

            Parameters
            ----------
            private_key : str
                Client private key.

            responder_id : str
                Responder public ID.

            msg_tag : str
                Response message tag.

            response : dict
                Received response.

            Returns
            -------
            confirmation : str
                Any confirmation string.
            """
            return self._handle_response(private_key, responder_id, msg_tag, response)

        def bind_receive_message(self, mtype, function, declare=True, metadata=None):
            """
            Bind a specific MType to a function or class method, being intended for
            a call or a notification.

            The function must be of the form::

                def my_function_or_method(<self,> private_key, sender_id, msg_id,
                                          mtype, params, extra)

            where ``private_key`` is the client private-key, ``sender_id`` is the
            notification sender ID, ``msg_id`` is the Hub message-id (calls only,
            otherwise is `None`), ``mtype`` is the message MType, ``params`` is the
            message parameter set (content of ``"samp.params"``) and ``extra`` is a
            dictionary containing any extra message map entry. The client is
            automatically declared subscribed to the MType by default.

            Parameters
            ----------
            mtype : str
                MType to be caught.

            function : callable
                Application function to be used when ``mtype`` is received.

            declare : bool, optional
                Specify whether the client must be automatically declared as
                subscribed to the MType (see also
                :meth:`~astropy.samp.client.SAMPClient.declare_subscriptions`).

            metadata : dict, optional
                Dictionary containing additional metadata to declare associated
                with the MType subscribed to (see also
                :meth:`~astropy.samp.client.SAMPClient.declare_subscriptions`).
            """

            self.bind_receive_call(mtype, function, declare=declare, metadata=metadata)

            self.bind_receive_notification(
                mtype, function, declare=declare, metadata=metadata
            )

        def bind_receive_notification(self, mtype, function, declare=True, metadata=None):
            """
            Bind a specific MType notification to a function or class method.

            The function must be of the form::

                def my_function_or_method(<self,> private_key, sender_id, mtype,
                                          params, extra)

            where ``private_key`` is the client private-key, ``sender_id`` is the
            notification sender ID, ``mtype`` is the message MType, ``params`` is
            the notified message parameter set (content of ``"samp.params"``) and
            ``extra`` is a dictionary containing any extra message map entry. The
            client is automatically declared subscribed to the MType by default.

            Parameters
            ----------
            mtype : str
                MType to be caught.

            function : callable
                Application function to be used when ``mtype`` is received.

            declare : bool, optional
                Specify whether the client must be automatically declared as
                subscribed to the MType (see also
                :meth:`~astropy.samp.client.SAMPClient.declare_subscriptions`).

            metadata : dict, optional
                Dictionary containing additional metadata to declare associated
                with the MType subscribed to (see also
                :meth:`~astropy.samp.client.SAMPClient.declare_subscriptions`).
            """
            if self._callable:
                if not metadata:
                    metadata = {}
                self._notification_bindings[mtype] = [function, metadata]
                if declare:
                    self._declare_subscriptions()
            else:
                raise SAMPClientError("Client not callable.")

        def bind_receive_call(self, mtype, function, declare=True, metadata=None):
            """
            Bind a specific MType call to a function or class method.

            The function must be of the form::

                def my_function_or_method(<self,> private_key, sender_id, msg_id,
                                          mtype, params, extra)

            where ``private_key`` is the client private-key, ``sender_id`` is the
            notification sender ID, ``msg_id`` is the Hub message-id, ``mtype`` is
            the message MType, ``params`` is the message parameter set (content of
            ``"samp.params"``) and ``extra`` is a dictionary containing any extra
            message map entry. The client is automatically declared subscribed to
            the MType by default.

            Parameters
            ----------
            mtype : str
                MType to be caught.

            function : callable
                Application function to be used when ``mtype`` is received.

            declare : bool, optional
                Specify whether the client must be automatically declared as
                subscribed to the MType (see also
                :meth:`~astropy.samp.client.SAMPClient.declare_subscriptions`).

            metadata : dict, optional
                Dictionary containing additional metadata to declare associated
                with the MType subscribed to (see also
                :meth:`~astropy.samp.client.SAMPClient.declare_subscriptions`).
            """
            if self._callable:
                if not metadata:
                    metadata = {}
                self._call_bindings[mtype] = [function, metadata]
                if declare:
                    self._declare_subscriptions()
            else:
                raise SAMPClientError("Client not callable.")

        def bind_receive_response(self, msg_tag, function):
            """
            Bind a specific msg-tag response to a function or class method.

            The function must be of the form::

                def my_function_or_method(<self,> private_key, responder_id,
                                          msg_tag, response)

            where ``private_key`` is the client private-key, ``responder_id`` is
            the message responder ID, ``msg_tag`` is the message-tag provided at
            call time and ``response`` is the response received.

            Parameters
            ----------
            msg_tag : str
                Message-tag to be caught.

            function : callable
                Application function to be used when ``msg_tag`` is received.
            """
            if self._callable:
                self._response_bindings[msg_tag] = function
            else:
                raise SAMPClientError("Client not callable.")

        def unbind_receive_notification(self, mtype, declare=True):
            """
            Remove from the notifications binding table the specified MType and
            unsubscribe the client from it (if required).

            Parameters
            ----------
            mtype : str
                MType to be removed.

            declare : bool
                Specify whether the client must be automatically declared as
                unsubscribed from the MType (see also
                :meth:`~astropy.samp.client.SAMPClient.declare_subscriptions`).
            """
            if self._callable:
                del self._notification_bindings[mtype]
                if declare:
                    self._declare_subscriptions()
            else:
                raise SAMPClientError("Client not callable.")

        def unbind_receive_call(self, mtype, declare=True):
            """
            Remove from the calls binding table the specified MType and unsubscribe
            the client from it (if required).

            Parameters
            ----------
            mtype : str
                MType to be removed.

            declare : bool
                Specify whether the client must be automatically declared as
                unsubscribed from the MType (see also
                :meth:`~astropy.samp.client.SAMPClient.declare_subscriptions`).
            """
            if self._callable:
                del self._call_bindings[mtype]
                if declare:
                    self._declare_subscriptions()
            else:
                raise SAMPClientError("Client not callable.")

        def unbind_receive_response(self, msg_tag):
            """
            Remove from the responses binding table the specified message-tag.

            Parameters
            ----------
            msg_tag : str
                Message-tag to be removed.
            """
            if self._callable:
                del self._response_bindings[msg_tag]
            else:
                raise SAMPClientError("Client not callable.")

        def declare_subscriptions(self, subscriptions=None):
            """
            Declares the MTypes the client wishes to subscribe to, implicitly
            defined with the MType binding methods
            :meth:`~astropy.samp.client.SAMPClient.bind_receive_notification`
            and :meth:`~astropy.samp.client.SAMPClient.bind_receive_call`.

            An optional ``subscriptions`` map can be added to the final map passed
            to the :meth:`~astropy.samp.hub_proxy.SAMPHubProxy.declare_subscriptions`
            method.

            Parameters
            ----------
            subscriptions : dict, optional
                Dictionary containing the list of MTypes to subscribe to, with the
                same format of the ``subscriptions`` map passed to the
                :meth:`~astropy.samp.hub_proxy.SAMPHubProxy.declare_subscriptions`
                method.
            """
            if self._callable:
                self._declare_subscriptions(subscriptions)
            else:
                raise SAMPClientError("Client not callable.")

        def register(self):
            """
            Register the client to the SAMP Hub.
            """
            if self.hub.is_connected:
                if self._private_key is not None:
                    raise SAMPClientError("Client already registered")

                result = self.hub.register(self.hub.lockfile["samp.secret"])

                if result["samp.self-id"] == "":
                    raise SAMPClientError(
                        "Registration failed - samp.self-id was not set by the hub."
                    )

                if result["samp.private-key"] == "":
                    raise SAMPClientError(
                        "Registration failed - samp.private-key was not set by the hub."
                    )

                self._public_id = result["samp.self-id"]
                self._private_key = result["samp.private-key"]
                self._hub_id = result["samp.hub-id"]

                if self._callable:
                    self._set_xmlrpc_callback()
                    self._declare_subscriptions()

                if self._metadata != {}:
                    self.declare_metadata()

                self._is_registered = True

            else:
                raise SAMPClientError(
                    "Unable to register to the SAMP Hub. Hub proxy not connected."
                )

        def unregister(self):
            """
            Unregister the client from the SAMP Hub.
            """
            if self.hub.is_connected:
                self._is_registered = False
                self.hub.unregister(self._private_key)
                self._hub_id = None
                self._public_id = None
                self._private_key = None
            else:
                raise SAMPClientError(
                    "Unable to unregister from the SAMP Hub. Hub proxy not connected."
                )

        def _set_xmlrpc_callback(self):
            if self.hub.is_connected and self._private_key is not None:
                self.hub.set_xmlrpc_callback(self._private_key, self._xmlrpcAddr)

        def _declare_subscriptions(self, subscriptions=None):
            if self.hub.is_connected and self._private_key is not None:
                mtypes_dict = {}
                # Collect notification mtypes and metadata
                for mtype in self._notification_bindings.keys():
                    mtypes_dict[mtype] = copy.deepcopy(
                        self._notification_bindings[mtype][1]
                    )

                # Collect notification mtypes and metadata
                for mtype in self._call_bindings.keys():
                    mtypes_dict[mtype] = copy.deepcopy(self._call_bindings[mtype][1])

                # Add optional subscription map
                if subscriptions:
                    mtypes_dict.update(copy.deepcopy(subscriptions))

                self.hub.declare_subscriptions(self._private_key, mtypes_dict)

            else:
                raise SAMPClientError(
                    "Unable to declare subscriptions. Hub "
                    "unreachable or not connected or client "
                    "not registered."
                )

        def declare_metadata(self, metadata=None):
            """
            Declare the client application metadata supported.

            Parameters
            ----------
            metadata : dict, optional
                Dictionary containing the client application metadata as defined in
                the SAMP definition document. If omitted, then no metadata are
                declared.
            """
            if self.hub.is_connected and self._private_key is not None:
                if metadata is not None:
                    self._metadata.update(metadata)
                self.hub.declare_metadata(self._private_key, self._metadata)
            else:
                raise SAMPClientError(
                    "Unable to declare metadata. Hub "
                    "unreachable or not connected or client "
                    "not registered."
                )

        def get_private_key(self):
            """
            Return the client private key used for the Standard Profile
            communications obtained at registration time (``samp.private-key``).

            Returns
            -------
            key : str
                Client private key.
            """
            return self._private_key

        def get_public_id(self):
            """
            Return public client ID obtained at registration time
            (``samp.self-id``).

            Returns
            -------
            id : str
                Client public ID.
            """
            return self._public_id