Invites v2 endpoint (#952)

* Start converting v1 invite endpoint to v2

* Update gomatrixserverlib

* Early federationsender code for sending invites

* Sending invites sorta happens now

* Populate invite request with stripped state

* Remodel a bit, don't reflect received invites

* Handle invite_room_state

* Handle room versions a bit better

* Update gomatrixserverlib

* Tweak order in destinationQueue.next

* Revert check in processMessage

* Tweak federation sender destination queue code a bit

* Add comments

federationsender/queue/queue.go

@@ -80,6 +80,49 @@ func (oqs *OutgoingQueues) SendEvent(
 	return nil
 }
 
+// SendEvent sends an event to the destinations
+func (oqs *OutgoingQueues) SendInvite(
+	inviteReq *gomatrixserverlib.InviteV2Request,
+) error {
+	ev := inviteReq.Event()
+	stateKey := ev.StateKey()
+	if stateKey == nil {
+		log.WithFields(log.Fields{
+			"event_id": ev.EventID(),
+		}).Info("invite had no state key, dropping")
+		return nil
+	}
+
+	_, destination, err := gomatrixserverlib.SplitID('@', *stateKey)
+	if err != nil {
+		log.WithFields(log.Fields{
+			"event_id":  ev.EventID(),
+			"state_key": stateKey,
+		}).Info("failed to split destination from state key")
+		return nil
+	}
+
+	log.WithFields(log.Fields{
+		"event_id": ev.EventID(),
+	}).Info("Sending invite")
+
+	oqs.queuesMutex.Lock()
+	defer oqs.queuesMutex.Unlock()
+	oq := oqs.queues[destination]
+	if oq == nil {
+		oq = &destinationQueue{
+			origin:      oqs.origin,
+			destination: destination,
+			client:      oqs.client,
+		}
+		oqs.queues[destination] = oq
+	}
+
+	oq.sendInvite(inviteReq)
+
+	return nil
+}
+
 // SendEDU sends an EDU event to the destinations
 func (oqs *OutgoingQueues) SendEDU(
 	e *gomatrixserverlib.EDU, origin gomatrixserverlib.ServerName,