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#!/usr/bin/env python

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# -*- coding: utf-8 -*-

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# This file is part of Beremiz, a Integrated Development Environment for

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# programming IEC 61131-3 automates supporting plcopen standard and CanFestival.

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#

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# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD

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# Copyright (C) 2017: Andrey Skvortsov

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#

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# See COPYING file for copyrights details.

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#

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# This program is free software; you can redistribute it and/or

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# modify it under the terms of the GNU General Public License

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# as published by the Free Software Foundation; either version 2

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# of the License, or (at your option) any later version.

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#

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# This program is distributed in the hope that it will be useful,

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# but WITHOUT ANY WARRANTY; without even the implied warranty of

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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

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# GNU General Public License for more details.

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#

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# You should have received a copy of the GNU General Public License

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# along with this program; if not, write to the Free Software

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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

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# Package initialisation

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import os

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import importlib

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from os import listdir, path

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from connectors.ConnectorBase import ConnectorBase

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connectors_packages = ["PYRO"]

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def _GetLocalConnectorClassFactory(name):

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    return lambda: getattr(importlib.import_module(f"connectors.{name}"),

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                           f"{name}_connector_factory")

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connectors = {name: _GetLocalConnectorClassFactory(name)

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              for name in connectors_packages}

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_dialogs_imported = False

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per_URI_connectors = None

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schemes = None

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# lazy import of connectors dialogs, only if used

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def _Import_Dialogs():

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    global per_URI_connectors, schemes, _dialogs_imported

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    if not _dialogs_imported:

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        _dialogs_imported = True

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        per_URI_connectors = {}

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        schemes = []

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        for con_name in connectors_packages:

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            module = importlib.import_module(f"connectors.{con_name}_dialog")

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            for scheme in module.Schemes:

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                per_URI_connectors[scheme] = getattr(module, con_name + '_dialog')

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                schemes += [scheme]

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LocalHost = os.environ.get("BEREMIZ_LOCAL_HOST", "localhost")

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def ConnectorFactory(uri, confnodesroot):

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    """

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    Return a connector corresponding to the URI

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    or None if cannot connect to URI

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    """

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    _scheme = uri.split("://")[0].upper()

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    # commented code to enable for MDNS:// support

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    # _scheme, location = uri.split("://")

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    # _scheme = _scheme.upper()

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    if _scheme == "LOCAL":

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        # Local is special case

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        # pyro connection to local runtime

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        # started on demand, listening on random port

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        scheme = "PYRO"

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        runtime_port = confnodesroot.StartLocalRuntime()

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        uri = f"PYRO://{LocalHost}:{runtime_port}"

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    # commented code to enable for MDNS:// support

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    # elif _scheme == "MDNS":

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    #     try:

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    #         from zeroconf import Zeroconf

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    #         r = Zeroconf()

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    #         i = r.get_service_info(zeroconf_service_type, location)

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    #         if i is None:

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    #             raise Exception("'%s' not found" % location)

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    #         ip = str(socket.inet_ntoa(i.address))

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    #         port = str(i.port)

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    #         newlocation = ip + ':' + port

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    #         confnodesroot.logger.write(_("'{a1}' is located at {a2}\n").format(a1=location, a2=newlocation))

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    #         location = newlocation

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    #         # not a bug, but a workaround against obvious downgrade attack

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    #         scheme = "PYROS"

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    #         r.close()

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    #     except Exception:

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    #         confnodesroot.logger.write_error(_("MDNS resolution failure for '%s'\n") % location)

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    #         confnodesroot.logger.write_error(traceback.format_exc())

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    #         return None

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    elif _scheme in connectors:

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        scheme = _scheme

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    elif _scheme[-1] == 'S' and _scheme[:-1] in connectors:

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        scheme = _scheme[:-1]

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    else:

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        return None

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    # import module according to uri type and get connector specific baseclass

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    # first call to import the module,

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    # then call with parameters to create the class

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    connector_specific_class = connectors[scheme]()(uri, confnodesroot)

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    if connector_specific_class is None:

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        return None

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    # new class inheriting from generic and specific connector base classes

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    return type(_scheme + "_connector",

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                (ConnectorBase, connector_specific_class), {})()

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def EditorClassFromScheme(scheme):

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    _Import_Dialogs()

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    return per_URI_connectors.get(scheme, None)

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def ConnectorSchemes():

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    _Import_Dialogs()

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    return schemes