1 files changed, 138 insertions, 0 deletions
diff --git a/synapse/server_notices/consent_server_notices.py b/synapse/server_notices/consent_server_notices.py
new file mode 100644
index 0000000000..5e3044d164
--- /dev/null
+++ b/synapse/server_notices/consent_server_notices.py
@@ -0,0 +1,138 @@
+# -*- coding: utf-8 -*-
+# Copyright 2018 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.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+import logging
+
+from six import iteritems, string_types
+
+from twisted.internet import defer
+
+from synapse.api.errors import SynapseError
+from synapse.api.urls import ConsentURIBuilder
+from synapse.config import ConfigError
+from synapse.types import get_localpart_from_id
+
+logger = logging.getLogger(__name__)
+
+
+class ConsentServerNotices(object):
+    """Keeps track of whether we need to send users server_notices about
+    privacy policy consent, and sends one if we do.
+    """
+    def __init__(self, hs):
+        """
+
+        Args:
+            hs (synapse.server.HomeServer):
+        """
+        self._server_notices_manager = hs.get_server_notices_manager()
+        self._store = hs.get_datastore()
+
+        self._users_in_progress = set()
+
+        self._current_consent_version = hs.config.user_consent_version
+        self._server_notice_content = hs.config.user_consent_server_notice_content
+        self._send_to_guests = hs.config.user_consent_server_notice_to_guests
+
+        if self._server_notice_content is not None:
+            if not self._server_notices_manager.is_enabled():
+                raise ConfigError(
+                    "user_consent configuration requires server notices, but "
+                    "server notices are not enabled.",
+                )
+            if 'body' not in self._server_notice_content:
+                raise ConfigError(
+                    "user_consent server_notice_consent must contain a 'body' "
+                    "key.",
+                )
+
+            self._consent_uri_builder = ConsentURIBuilder(hs.config)
+
+    @defer.inlineCallbacks
+    def maybe_send_server_notice_to_user(self, user_id):
+        """Check if we need to send a notice to this user, and does so if so
+
+        Args:
+            user_id (str): user to check
+
+        Returns:
+            Deferred
+        """
+        if self._server_notice_content is None:
+            # not enabled
+            return
+
+        # make sure we don't send two messages to the same user at once
+        if user_id in self._users_in_progress:
+            return
+        self._users_in_progress.add(user_id)
+        try:
+            u = yield self._store.get_user_by_id(user_id)
+
+            if u["is_guest"] and not self._send_to_guests:
+                # don't send to guests
+                return
+
+            if u["consent_version"] == self._current_consent_version:
+                # user has already consented
+                return
+
+            if u["consent_server_notice_sent"] == self._current_consent_version:
+                # we've already sent a notice to the user
+                return
+
+            # need to send a message.
+            try:
+                consent_uri = self._consent_uri_builder.build_user_consent_uri(
+                    get_localpart_from_id(user_id),
+                )
+                content = copy_with_str_subst(
+                    self._server_notice_content, {
+                        'consent_uri': consent_uri,
+                    },
+                )
+                yield self._server_notices_manager.send_notice(
+                    user_id, content,
+                )
+                yield self._store.user_set_consent_server_notice_sent(
+                    user_id, self._current_consent_version,
+                )
+            except SynapseError as e:
+                logger.error("Error sending server notice about user consent: %s", e)
+        finally:
+            self._users_in_progress.remove(user_id)
+
+
+def copy_with_str_subst(x, substitutions):
+    """Deep-copy a structure, carrying out string substitions on any strings
+
+    Args:
+        x (object): structure to be copied
+        substitutions (object): substitutions to be made - passed into the
+            string '%' operator
+
+    Returns:
+        copy of x
+    """
+    if isinstance(x, string_types):
+        return x % substitutions
+    if isinstance(x, dict):
+        return {
+            k: copy_with_str_subst(v, substitutions) for (k, v) in iteritems(x)
+        }
+    if isinstance(x, (list, tuple)):
+        return [copy_with_str_subst(y) for y in x]
+
+    # assume it's uninterested and can be shallow-copied.
+    return x