Produce OTK counts in /sync response (#1235)

* Add QueryOneTimeKeys for /sync extensions

* Unbreak tests

* Produce OTK counts in /sync response

* Linting

4 files changed, 32 insertions, 7 deletions

diff --git a/syncapi/internal/keychange.go b/syncapi/internal/keychange.go
index 0272ffc0..66134d79 100644
--- a/syncapi/internal/keychange.go
+++ b/syncapi/internal/keychange.go
@@ -29,6 +29,20 @@ import (
 
 const DeviceListLogName = "dl"
 
+// DeviceOTKCounts adds one-time key counts to the /sync response
+func DeviceOTKCounts(ctx context.Context, keyAPI keyapi.KeyInternalAPI, userID, deviceID string, res *types.Response) error {
+	var queryRes api.QueryOneTimeKeysResponse
+	keyAPI.QueryOneTimeKeys(ctx, &api.QueryOneTimeKeysRequest{
+		UserID:   userID,
+		DeviceID: deviceID,
+	}, &queryRes)
+	if queryRes.Error != nil {
+		return queryRes.Error
+	}
+	res.DeviceListsOTKCount = queryRes.Count.KeyCount
+	return nil
+}
+
 // DeviceListCatchup fills in the given response for the given user ID to bring it up-to-date with device lists. hasNew=true if the response
 // was filled in, else false if there are no new device list changes because there is nothing to catch up on. The response MUST
 // be already filled in with join/leave information.
@@ -36,6 +50,7 @@ func DeviceListCatchup(
 	ctx context.Context, keyAPI keyapi.KeyInternalAPI, stateAPI currentstateAPI.CurrentStateInternalAPI,
 	userID string, res *types.Response, from, to types.StreamingToken,
 ) (hasNew bool, err error) {
+
 	// Track users who we didn't track before but now do by virtue of sharing a room with them, or not.
 	newlyJoinedRooms := joinedRooms(res, userID)
 	newlyLeftRooms := leftRooms(res)
diff --git a/syncapi/internal/keychange_test.go b/syncapi/internal/keychange_test.go
index 2c3d154d..af456af4 100644
--- a/syncapi/internal/keychange_test.go
+++ b/syncapi/internal/keychange_test.go
@@ -39,6 +39,9 @@ func (k *mockKeyAPI) QueryKeys(ctx context.Context, req *keyapi.QueryKeysRequest
 }
 func (k *mockKeyAPI) QueryKeyChanges(ctx context.Context, req *keyapi.QueryKeyChangesRequest, res *keyapi.QueryKeyChangesResponse) {
 }
+func (k *mockKeyAPI) QueryOneTimeKeys(ctx context.Context, req *keyapi.QueryOneTimeKeysRequest, res *keyapi.QueryOneTimeKeysResponse) {
+
+}
 
 type mockCurrentStateAPI struct {
 	roomIDToJoinedMembers map[string][]string
diff --git a/syncapi/sync/requestpool.go b/syncapi/sync/requestpool.go
index b530b34d..12c597bb 100644
--- a/syncapi/sync/requestpool.go
+++ b/syncapi/sync/requestpool.go
@@ -192,8 +192,9 @@ func (rp *RequestPool) OnIncomingKeyChangeRequest(req *http.Request, device *use
 	}
 }
 
-func (rp *RequestPool) currentSyncForUser(req syncRequest, latestPos types.StreamingToken) (res *types.Response, err error) {
-	res = types.NewResponse()
+// nolint:gocyclo
+func (rp *RequestPool) currentSyncForUser(req syncRequest, latestPos types.StreamingToken) (*types.Response, error) {
+	res := types.NewResponse()
 
 	since := types.NewStreamToken(0, 0, nil)
 	if req.since != nil {
@@ -213,17 +214,21 @@ func (rp *RequestPool) currentSyncForUser(req syncRequest, latestPos types.Strea
 		res, err = rp.db.IncrementalSync(req.ctx, res, req.device, *req.since, latestPos, req.limit, req.wantFullState)
 	}
 	if err != nil {
-		return
+		return res, err
 	}
 
 	accountDataFilter := gomatrixserverlib.DefaultEventFilter() // TODO: use filter provided in req instead
 	res, err = rp.appendAccountData(res, req.device.UserID, req, latestPos.PDUPosition(), &accountDataFilter)
 	if err != nil {
-		return
+		return res, err
 	}
 	res, err = rp.appendDeviceLists(res, req.device.UserID, since, latestPos)
 	if err != nil {
-		return
+		return res, err
+	}
+	err = internal.DeviceOTKCounts(req.ctx, rp.keyAPI, req.device.UserID, req.device.ID, res)
+	if err != nil {
+		return res, err
 	}
 
 	// Before we return the sync response, make sure that we take action on
@@ -233,7 +238,7 @@ func (rp *RequestPool) currentSyncForUser(req syncRequest, latestPos types.Strea
 		// Handle the updates and deletions in the database.
 		err = rp.db.CleanSendToDeviceUpdates(context.Background(), updates, deletions, since)
 		if err != nil {
-			return
+			return res, err
 		}
 	}
 	if len(events) > 0 {
@@ -250,7 +255,7 @@ func (rp *RequestPool) currentSyncForUser(req syncRequest, latestPos types.Strea
 		}
 	}
 
-	return
+	return res, err
 }
 
 func (rp *RequestPool) appendDeviceLists(
diff --git a/syncapi/types/types.go b/syncapi/types/types.go
index 4761cce2..f465d9ff 100644
--- a/syncapi/types/types.go
+++ b/syncapi/types/types.go
@@ -393,6 +393,7 @@ type Response struct {
 		Changed []string `json:"changed,omitempty"`
 		Left    []string `json:"left,omitempty"`
 	} `json:"device_lists,omitempty"`
+	DeviceListsOTKCount map[string]int `json:"device_one_time_keys_count"`
 }
 
 // NewResponse creates an empty response with initialised maps.
@@ -411,6 +412,7 @@ func NewResponse() *Response {
 	res.AccountData.Events = make([]gomatrixserverlib.ClientEvent, 0)
 	res.Presence.Events = make([]gomatrixserverlib.ClientEvent, 0)
 	res.ToDevice.Events = make([]gomatrixserverlib.SendToDeviceEvent, 0)
+	res.DeviceListsOTKCount = make(map[string]int)
 
 	return &res
 }