--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/backend/plugins/plugin_misc_watched.py	Fri Jun 02 11:49:51 2023 +0200
@@ -0,0 +1,91 @@
+#!/usr/bin/env python3
+
+
+# SàT plugin to be notified on some entities presence
+# 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 _, D_
+from libervia.backend.core.constants import Const as C
+from libervia.backend.core.log import getLogger
+
+log = getLogger(__name__)
+from libervia.backend.core import exceptions
+from libervia.backend.tools import xml_tools
+
+
+PLUGIN_INFO = {
+    C.PI_NAME: "Watched",
+    C.PI_IMPORT_NAME: "WATCHED",
+    C.PI_TYPE: "Misc",
+    C.PI_PROTOCOLS: [],
+    C.PI_DEPENDENCIES: [],
+    C.PI_MAIN: "Watched",
+    C.PI_HANDLER: "no",
+    C.PI_DESCRIPTION: _(
+        """Watch for entities presence, and send notification accordingly"""
+    ),
+}
+
+
+CATEGORY = D_("Misc")
+NAME = "Watched"
+NOTIF = D_("Watched entity {entity} is connected")
+
+
+class Watched(object):
+    params = """
+    <params>
+    <individual>
+    <category name="{category_name}" label="{category_label}">
+        <param name="{name}" label="{label}" type="jids_list" security="0" />
+    </category>
+    </individual>
+    </params>
+    """.format(
+        category_name=CATEGORY, category_label=_(CATEGORY), name=NAME, label=_(NAME)
+    )
+
+    def __init__(self, host):
+        log.info(_("Watched initialisation"))
+        self.host = host
+        host.memory.update_params(self.params)
+        host.trigger.add("presence_received", self._presence_received_trigger)
+
+    def _presence_received_trigger(self, client, entity, show, priority, statuses):
+        if show == C.PRESENCE_UNAVAILABLE:
+            return True
+
+        # we check that the previous presence was unavailable (no notification else)
+        try:
+            old_show = self.host.memory.get_entity_datum(
+                client, entity, "presence").show
+        except (KeyError, exceptions.UnknownEntityError):
+            old_show = C.PRESENCE_UNAVAILABLE
+
+        if old_show == C.PRESENCE_UNAVAILABLE:
+            watched = self.host.memory.param_get_a(
+                NAME, CATEGORY, profile_key=client.profile)
+            if entity in watched or entity.userhostJID() in watched:
+                self.host.action_new(
+                    {
+                        "xmlui": xml_tools.note(
+                            _(NOTIF).format(entity=entity.full())
+                        ).toXml()
+                    },
+                    profile=client.profile,
+                )
+
+        return True