--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/backend/plugins/plugin_exp_pubsub_hook.py	Fri Jun 02 11:49:51 2023 +0200
@@ -0,0 +1,286 @@
+#!/usr/bin/env python3
+
+
+# SAT plugin for Pubsub Hooks
+# Copyright (C) 2009-2021 Jérôme Poisson (goffi@goffi.org)
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from libervia.backend.core.i18n import _
+from libervia.backend.core.constants import Const as C
+from libervia.backend.core import exceptions
+from libervia.backend.core.log import getLogger
+from libervia.backend.memory import persistent
+from twisted.words.protocols.jabber import jid
+from twisted.internet import defer
+
+log = getLogger(__name__)
+
+NS_PUBSUB_HOOK = "PUBSUB_HOOK"
+
+PLUGIN_INFO = {
+    C.PI_NAME: "PubSub Hook",
+    C.PI_IMPORT_NAME: NS_PUBSUB_HOOK,
+    C.PI_TYPE: "EXP",
+    C.PI_PROTOCOLS: [],
+    C.PI_DEPENDENCIES: ["XEP-0060"],
+    C.PI_MAIN: "PubsubHook",
+    C.PI_HANDLER: "no",
+    C.PI_DESCRIPTION: _(
+        """Experimental plugin to launch on action on Pubsub notifications"""
+    ),
+}
+
+#  python module
+HOOK_TYPE_PYTHON = "python"
+# python file path
+HOOK_TYPE_PYTHON_FILE = "python_file"
+# python code directly
+HOOK_TYPE_PYTHON_CODE = "python_code"
+HOOK_TYPES = (HOOK_TYPE_PYTHON, HOOK_TYPE_PYTHON_FILE, HOOK_TYPE_PYTHON_CODE)
+
+
+class PubsubHook(object):
+    def __init__(self, host):
+        log.info(_("PubSub Hook initialization"))
+        self.host = host
+        self.node_hooks = {}  # keep track of the number of hooks per node (for all profiles)
+        host.bridge.add_method(
+            "ps_hook_add", ".plugin", in_sign="ssssbs", out_sign="", method=self._addHook
+        )
+        host.bridge.add_method(
+            "ps_hook_remove",
+            ".plugin",
+            in_sign="sssss",
+            out_sign="i",
+            method=self._removeHook,
+        )
+        host.bridge.add_method(
+            "ps_hook_list",
+            ".plugin",
+            in_sign="s",
+            out_sign="aa{ss}",
+            method=self._list_hooks,
+        )
+
+    @defer.inlineCallbacks
+    def profile_connected(self, client):
+        hooks = client._hooks = persistent.PersistentBinaryDict(
+            NS_PUBSUB_HOOK, client.profile
+        )
+        client._hooks_temporary = {}
+        yield hooks.load()
+        for node in hooks:
+            self._install_node_manager(client, node)
+
+    def profile_disconnected(self, client):
+        for node in client._hooks:
+            self._remove_node_manager(client, node)
+
+    def _install_node_manager(self, client, node):
+        if node in self.node_hooks:
+            log.debug(_("node manager already set for {node}").format(node=node))
+            self.node_hooks[node] += 1
+        else:
+            # first hook on this node
+            self.host.plugins["XEP-0060"].add_managed_node(
+                node, items_cb=self._items_received
+            )
+            self.node_hooks[node] = 0
+            log.info(_("node manager installed on {node}").format(node=node))
+
+    def _remove_node_manager(self, client, node):
+        try:
+            self.node_hooks[node] -= 1
+        except KeyError:
+            log.error(_("trying to remove a {node} without hook").format(node=node))
+        else:
+            if self.node_hooks[node] == 0:
+                del self.node_hooks[node]
+                self.host.plugins["XEP-0060"].remove_managed_node(node, self._items_received)
+                log.debug(_("hook removed"))
+            else:
+                log.debug(_("node still needed for an other hook"))
+
+    def install_hook(self, client, service, node, hook_type, hook_arg, persistent):
+        if hook_type not in HOOK_TYPES:
+            raise exceptions.DataError(
+                _("{hook_type} is not handled").format(hook_type=hook_type)
+            )
+        if hook_type != HOOK_TYPE_PYTHON_FILE:
+            raise NotImplementedError(
+                _("{hook_type} hook type not implemented yet").format(
+                    hook_type=hook_type
+                )
+            )
+        self._install_node_manager(client, node)
+        hook_data = {"service": service, "type": hook_type, "arg": hook_arg}
+
+        if persistent:
+            hooks_list = client._hooks.setdefault(node, [])
+            hooks_list.append(hook_data)
+            client._hooks.force(node)
+        else:
+            hooks_list = client._hooks_temporary.setdefault(node, [])
+            hooks_list.append(hook_data)
+
+        log.info(
+            _("{persistent} hook installed on {node} for {profile}").format(
+                persistent=_("persistent") if persistent else _("temporary"),
+                node=node,
+                profile=client.profile,
+            )
+        )
+
+    def _items_received(self, client, itemsEvent):
+        node = itemsEvent.nodeIdentifier
+        for hooks in (client._hooks, client._hooks_temporary):
+            if node not in hooks:
+                continue
+            hooks_list = hooks[node]
+            for hook_data in hooks_list[:]:
+                if hook_data["service"] != itemsEvent.sender.userhostJID():
+                    continue
+                try:
+                    callback = hook_data["callback"]
+                except KeyError:
+                    # first time we get this hook, we create the callback
+                    hook_type = hook_data["type"]
+                    try:
+                        if hook_type == HOOK_TYPE_PYTHON_FILE:
+                            hook_globals = {}
+                            exec(compile(open(hook_data["arg"], "rb").read(), hook_data["arg"], 'exec'), hook_globals)
+                            callback = hook_globals["hook"]
+                        else:
+                            raise NotImplementedError(
+                                _("{hook_type} hook type not implemented yet").format(
+                                    hook_type=hook_type
+                                )
+                            )
+                    except Exception as e:
+                        log.warning(
+                            _(
+                                "Can't load Pubsub hook at node {node}, it will be removed: {reason}"
+                            ).format(node=node, reason=e)
+                        )
+                        hooks_list.remove(hook_data)
+                        continue
+
+                for item in itemsEvent.items:
+                    try:
+                        callback(self.host, client, item)
+                    except Exception as e:
+                        log.warning(
+                            _(
+                                "Error while running Pubsub hook for node {node}: {msg}"
+                            ).format(node=node, msg=e)
+                        )
+
+    def _addHook(self, service, node, hook_type, hook_arg, persistent, profile):
+        client = self.host.get_client(profile)
+        service = jid.JID(service) if service else client.jid.userhostJID()
+        return self.add_hook(
+            client,
+            service,
+            str(node),
+            str(hook_type),
+            str(hook_arg),
+            persistent,
+        )
+
+    def add_hook(self, client, service, node, hook_type, hook_arg, persistent):
+        r"""Add a hook which will be triggered on a pubsub notification
+
+        @param service(jid.JID): service of the node
+        @param node(unicode): Pubsub node
+        @param hook_type(unicode): type of the hook, one of:
+            - HOOK_TYPE_PYTHON: a python module (must be in path)
+                module must have a "hook" method which will be called
+            - HOOK_TYPE_PYTHON_FILE: a python file
+                file must have a "hook" method which will be called
+            - HOOK_TYPE_PYTHON_CODE: direct python code
+                /!\ Python hooks will be executed in SàT context,
+                with host, client and item as arguments, it means that:
+                    - they can do whatever they wants, so don't run untrusted hooks
+                    - they MUST NOT BLOCK, they are run in Twisted async environment and blocking would block whole SàT process
+                    - item are domish.Element
+        @param hook_arg(unicode): argument of the hook, depending on the hook_type
+            can be a module path, file path, python code
+        """
+        assert service is not None
+        return self.install_hook(client, service, node, hook_type, hook_arg, persistent)
+
+    def _removeHook(self, service, node, hook_type, hook_arg, profile):
+        client = self.host.get_client(profile)
+        service = jid.JID(service) if service else client.jid.userhostJID()
+        return self.remove_hook(client, service, node, hook_type or None, hook_arg or None)
+
+    def remove_hook(self, client, service, node, hook_type=None, hook_arg=None):
+        """Remove a persistent or temporaty root
+
+        @param service(jid.JID): service of the node
+        @param node(unicode): Pubsub node
+        @param hook_type(unicode, None): same as for [add_hook]
+            match all if None
+        @param hook_arg(unicode, None): same as for [add_hook]
+            match all if None
+        @return(int): number of hooks removed
+        """
+        removed = 0
+        for hooks in (client._hooks, client._hooks_temporary):
+            if node in hooks:
+                for hook_data in hooks[node]:
+                    if (
+                        service != hook_data["service"]
+                        or hook_type is not None
+                        and hook_type != hook_data["type"]
+                        or hook_arg is not None
+                        and hook_arg != hook_data["arg"]
+                    ):
+                        continue
+                    hooks[node].remove(hook_data)
+                    removed += 1
+                    if not hooks[node]:
+                        #  no more hooks, we can remove the node
+                        del hooks[node]
+                        self._remove_node_manager(client, node)
+                    else:
+                        if hooks == client._hooks:
+                            hooks.force(node)
+        return removed
+
+    def _list_hooks(self, profile):
+        hooks_list = self.list_hooks(self.host.get_client(profile))
+        for hook in hooks_list:
+            hook["service"] = hook["service"].full()
+            hook["persistent"] = C.bool_const(hook["persistent"])
+        return hooks_list
+
+    def list_hooks(self, client):
+        """return list of registered hooks"""
+        hooks_list = []
+        for hooks in (client._hooks, client._hooks_temporary):
+            persistent = hooks is client._hooks
+            for node, hooks_data in hooks.items():
+                for hook_data in hooks_data:
+                    hooks_list.append(
+                        {
+                            "service": hook_data["service"],
+                            "node": node,
+                            "type": hook_data["type"],
+                            "arg": hook_data["arg"],
+                            "persistent": persistent,
+                        }
+                    )
+        return hooks_list