Merge pull request #50 from matrix-org/application-services

Application Services

1 files changed, 147 insertions, 0 deletions

diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
new file mode 100644
index 0000000000..381b4cfc4a
--- /dev/null
+++ b/synapse/appservice/__init__.py
@@ -0,0 +1,147 @@
+# -*- coding: utf-8 -*-
+# Copyright 2015 OpenMarket 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.
+from synapse.api.constants import EventTypes
+
+import logging
+import re
+
+logger = logging.getLogger(__name__)
+
+
+class ApplicationService(object):
+    """Defines an application service. This definition is mostly what is
+    provided to the /register AS API.
+
+    Provides methods to check if this service is "interested" in events.
+    """
+    NS_USERS = "users"
+    NS_ALIASES = "aliases"
+    NS_ROOMS = "rooms"
+    # The ordering here is important as it is used to map database values (which
+    # are stored as ints representing the position in this list) to namespace
+    # values.
+    NS_LIST = [NS_USERS, NS_ALIASES, NS_ROOMS]
+
+    def __init__(self, token, url=None, namespaces=None, hs_token=None,
+                 sender=None, txn_id=None):
+        self.token = token
+        self.url = url
+        self.hs_token = hs_token
+        self.sender = sender
+        self.namespaces = self._check_namespaces(namespaces)
+        self.txn_id = txn_id
+
+    def _check_namespaces(self, namespaces):
+        # Sanity check that it is of the form:
+        # {
+        #   users: ["regex",...],
+        #   aliases: ["regex",...],
+        #   rooms: ["regex",...],
+        # }
+        if not namespaces:
+            return None
+
+        for ns in ApplicationService.NS_LIST:
+            if type(namespaces[ns]) != list:
+                raise ValueError("Bad namespace value for '%s'", ns)
+            for regex in namespaces[ns]:
+                if not isinstance(regex, basestring):
+                    raise ValueError("Expected string regex for ns '%s'", ns)
+        return namespaces
+
+    def _matches_regex(self, test_string, namespace_key):
+        if not isinstance(test_string, basestring):
+            logger.error(
+                "Expected a string to test regex against, but got %s",
+                test_string
+            )
+            return False
+
+        for regex in self.namespaces[namespace_key]:
+            if re.match(regex, test_string):
+                return True
+        return False
+
+    def _matches_user(self, event, member_list):
+        if (hasattr(event, "sender") and
+                self.is_interested_in_user(event.sender)):
+            return True
+        # also check m.room.member state key
+        if (hasattr(event, "type") and event.type == EventTypes.Member
+                and hasattr(event, "state_key")
+                and self.is_interested_in_user(event.state_key)):
+            return True
+        # check joined member events
+        for member in member_list:
+            if self.is_interested_in_user(member.state_key):
+                return True
+        return False
+
+    def _matches_room_id(self, event):
+        if hasattr(event, "room_id"):
+            return self.is_interested_in_room(event.room_id)
+        return False
+
+    def _matches_aliases(self, event, alias_list):
+        for alias in alias_list:
+            if self.is_interested_in_alias(alias):
+                return True
+        return False
+
+    def is_interested(self, event, restrict_to=None, aliases_for_event=None,
+                      member_list=None):
+        """Check if this service is interested in this event.
+
+        Args:
+            event(Event): The event to check.
+            restrict_to(str): The namespace to restrict regex tests to.
+            aliases_for_event(list): A list of all the known room aliases for
+            this event.
+            member_list(list): A list of all joined room members in this room.
+        Returns:
+            bool: True if this service would like to know about this event.
+        """
+        if aliases_for_event is None:
+            aliases_for_event = []
+        if member_list is None:
+            member_list = []
+
+        if restrict_to and restrict_to not in ApplicationService.NS_LIST:
+            # this is a programming error, so fail early and raise a general
+            # exception
+            raise Exception("Unexpected restrict_to value: %s". restrict_to)
+
+        if not restrict_to:
+            return (self._matches_user(event, member_list)
+                    or self._matches_aliases(event, aliases_for_event)
+                    or self._matches_room_id(event))
+        elif restrict_to == ApplicationService.NS_ALIASES:
+            return self._matches_aliases(event, aliases_for_event)
+        elif restrict_to == ApplicationService.NS_ROOMS:
+            return self._matches_room_id(event)
+        elif restrict_to == ApplicationService.NS_USERS:
+            return self._matches_user(event, member_list)
+
+    def is_interested_in_user(self, user_id):
+        return self._matches_regex(user_id, ApplicationService.NS_USERS)
+
+    def is_interested_in_alias(self, alias):
+        return self._matches_regex(alias, ApplicationService.NS_ALIASES)
+
+    def is_interested_in_room(self, room_id):
+        return self._matches_regex(room_id, ApplicationService.NS_ROOMS)
+
+    def __str__(self):
+        return "ApplicationService: %s" % (self.__dict__,)