From fa969cfdde72a2d136eba08eb99e00d47ddb5cdf Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Thu, 5 Oct 2017 12:39:18 +0100
Subject: [PATCH] Support for channel notifications

Add condition type to check the sender's power level and add a base
rule using it for @channel notifications.
---
 synapse/push/baserules.py                | 23 ++++++++++++++++++++++
 synapse/push/bulk_push_rule_evaluator.py | 19 +++++++++++++++++-
 synapse/push/push_rule_evaluator.py      | 25 +++++++++++++++++-------
 3 files changed, 59 insertions(+), 8 deletions(-)

diff --git a/synapse/push/baserules.py b/synapse/push/baserules.py
index 85effdfa4..354b1f449 100644
--- a/synapse/push/baserules.py
+++ b/synapse/push/baserules.py
@@ -1,4 +1,5 @@
 # Copyright 2015, 2016 OpenMarket Ltd
+# Copyright 2017 New Vector Ltd
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -238,6 +239,28 @@ BASE_APPEND_OVERRIDE_RULES = [
             }
         ]
     },
+    {
+        'rule_id': 'global/underride/.m.rule.channelnotif',
+        'conditions': [
+            {
+                'kind': 'event_match',
+                'key': 'content.body',
+                'pattern': '*@channel*',
+                '_id': '_channelnotif_content',
+            },
+            {
+                'kind': 'sender_power_level',
+                'is': '>=50',
+                '_id': '_channelnotif_pl',
+            },
+        ],
+        'actions': [
+            'notify', {
+                'set_tweak': 'highlight',
+                'value': True,
+            }
+        ]
+    }
 ]
 
 
diff --git a/synapse/push/bulk_push_rule_evaluator.py b/synapse/push/bulk_push_rule_evaluator.py
index b0d64aa6c..6459eec22 100644
--- a/synapse/push/bulk_push_rule_evaluator.py
+++ b/synapse/push/bulk_push_rule_evaluator.py
@@ -19,6 +19,7 @@ from twisted.internet import defer
 
 from .push_rule_evaluator import PushRuleEvaluatorForEvent
 
+from synapse.event_auth import get_user_power_level
 from synapse.api.constants import EventTypes, Membership
 from synapse.metrics import get_metrics_for
 from synapse.util.caches import metrics as cache_metrics
@@ -59,6 +60,7 @@ class BulkPushRuleEvaluator(object):
     def __init__(self, hs):
         self.hs = hs
         self.store = hs.get_datastore()
+        self.auth = hs.get_auth()
 
         self.room_push_rule_cache_metrics = cache_metrics.register_cache(
             "cache",
@@ -108,6 +110,17 @@ class BulkPushRuleEvaluator(object):
             self.room_push_rule_cache_metrics,
         )
 
+    @defer.inlineCallbacks
+    def _get_sender_power_level(self, event, context):
+        auth_events_ids = yield self.auth.compute_auth_events(
+            event, context.prev_state_ids, for_verification=False,
+        )
+        auth_events = yield self.store.get_events(auth_events_ids)
+        auth_events = {
+            (e.type, e.state_key): e for e in auth_events.values()
+        }
+        defer.returnValue(get_user_power_level(event.sender, auth_events))
+
     @defer.inlineCallbacks
     def action_for_event_by_user(self, event, context):
         """Given an event and context, evaluate the push rules and return
@@ -123,7 +136,11 @@ class BulkPushRuleEvaluator(object):
             event, context
         )
 
-        evaluator = PushRuleEvaluatorForEvent(event, len(room_members))
+        sender_power_level = yield self._get_sender_power_level(event, context)
+
+        evaluator = PushRuleEvaluatorForEvent(
+            event, len(room_members), sender_power_level
+        )
 
         condition_cache = {}
 
diff --git a/synapse/push/push_rule_evaluator.py b/synapse/push/push_rule_evaluator.py
index 65f9a63fd..9cf3f9c63 100644
--- a/synapse/push/push_rule_evaluator.py
+++ b/synapse/push/push_rule_evaluator.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2015, 2016 OpenMarket Ltd
+# Copyright 2015 New Vector Ltd
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -29,6 +30,12 @@ INEQUALITY_EXPR = re.compile("^([=<>]*)([0-9]*)$")
 
 
 def _room_member_count(ev, condition, room_member_count):
+    return _test_ineq_condition(condition, room_member_count)
+
+def _sender_power_level(ev, condition, power_level):
+    return _test_ineq_condition(condition, power_level)
+
+def _test_ineq_condition(condition, number):
     if 'is' not in condition:
         return False
     m = INEQUALITY_EXPR.match(condition['is'])
@@ -41,19 +48,18 @@ def _room_member_count(ev, condition, room_member_count):
     rhs = int(rhs)
 
     if ineq == '' or ineq == '==':
-        return room_member_count == rhs
+        return number == rhs
     elif ineq == '<':
-        return room_member_count < rhs
+        return number < rhs
     elif ineq == '>':
-        return room_member_count > rhs
+        return number > rhs
     elif ineq == '>=':
-        return room_member_count >= rhs
+        return number >= rhs
     elif ineq == '<=':
-        return room_member_count <= rhs
+        return number <= rhs
     else:
         return False
 
-
 def tweaks_for_actions(actions):
     tweaks = {}
     for a in actions:
@@ -65,9 +71,10 @@ def tweaks_for_actions(actions):
 
 
 class PushRuleEvaluatorForEvent(object):
-    def __init__(self, event, room_member_count):
+    def __init__(self, event, room_member_count, sender_power_level):
         self._event = event
         self._room_member_count = room_member_count
+        self._sender_power_level = sender_power_level
 
         # Maps strings of e.g. 'content.body' -> event["content"]["body"]
         self._value_cache = _flatten_dict(event)
@@ -81,6 +88,10 @@ class PushRuleEvaluatorForEvent(object):
             return _room_member_count(
                 self._event, condition, self._room_member_count
             )
+        elif condition['kind'] == 'sender_power_level':
+            return _sender_power_level(
+                self._event, condition, self._sender_power_level
+            )
         else:
             return True