1 files changed, 141 insertions, 0 deletions
diff --git a/federationapi/consumers/receipts.go b/federationapi/consumers/receipts.go
new file mode 100644
index 00000000..9300451e
--- /dev/null
+++ b/federationapi/consumers/receipts.go
@@ -0,0 +1,141 @@
+// Copyright 2022 The Matrix.org Foundation C.I.C.
+//
+// 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.
+
+package consumers
+
+import (
+	"context"
+	"encoding/json"
+	"strconv"
+
+	"github.com/getsentry/sentry-go"
+	"github.com/matrix-org/dendrite/federationapi/queue"
+	"github.com/matrix-org/dendrite/federationapi/storage"
+	fedTypes "github.com/matrix-org/dendrite/federationapi/types"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/setup/jetstream"
+	"github.com/matrix-org/dendrite/setup/process"
+	syncTypes "github.com/matrix-org/dendrite/syncapi/types"
+	"github.com/matrix-org/gomatrixserverlib"
+	"github.com/nats-io/nats.go"
+	log "github.com/sirupsen/logrus"
+)
+
+// OutputReceiptConsumer consumes events that originate in the clientapi.
+type OutputReceiptConsumer struct {
+	ctx        context.Context
+	jetstream  nats.JetStreamContext
+	durable    string
+	db         storage.Database
+	queues     *queue.OutgoingQueues
+	ServerName gomatrixserverlib.ServerName
+	topic      string
+}
+
+// NewOutputReceiptConsumer creates a new OutputReceiptConsumer. Call Start() to begin consuming typing events.
+func NewOutputReceiptConsumer(
+	process *process.ProcessContext,
+	cfg *config.FederationAPI,
+	js nats.JetStreamContext,
+	queues *queue.OutgoingQueues,
+	store storage.Database,
+) *OutputReceiptConsumer {
+	return &OutputReceiptConsumer{
+		ctx:        process.Context(),
+		jetstream:  js,
+		queues:     queues,
+		db:         store,
+		ServerName: cfg.Matrix.ServerName,
+		durable:    cfg.Matrix.JetStream.Durable("FederationAPIReceiptConsumer"),
+		topic:      cfg.Matrix.JetStream.Prefixed(jetstream.OutputReceiptEvent),
+	}
+}
+
+// Start consuming from the clientapi
+func (t *OutputReceiptConsumer) Start() error {
+	return jetstream.JetStreamConsumer(
+		t.ctx, t.jetstream, t.topic, t.durable, t.onMessage,
+		nats.DeliverAll(), nats.ManualAck(), nats.HeadersOnly(),
+	)
+}
+
+// onMessage is called in response to a message received on the receipt
+// events topic from the client api.
+func (t *OutputReceiptConsumer) onMessage(ctx context.Context, msg *nats.Msg) bool {
+	receipt := syncTypes.OutputReceiptEvent{
+		UserID:  msg.Header.Get(jetstream.UserID),
+		RoomID:  msg.Header.Get(jetstream.RoomID),
+		EventID: msg.Header.Get(jetstream.EventID),
+		Type:    msg.Header.Get("type"),
+	}
+
+	// only send receipt events which originated from us
+	_, receiptServerName, err := gomatrixserverlib.SplitID('@', receipt.UserID)
+	if err != nil {
+		log.WithError(err).WithField("user_id", receipt.UserID).Error("failed to extract domain from receipt sender")
+		return true
+	}
+	if receiptServerName != t.ServerName {
+		return true
+	}
+
+	timestamp, err := strconv.Atoi(msg.Header.Get("timestamp"))
+	if err != nil {
+		// If the message was invalid, log it and move on to the next message in the stream
+		log.WithError(err).Errorf("EDU output log: message parse failure")
+		sentry.CaptureException(err)
+		return true
+	}
+
+	receipt.Timestamp = gomatrixserverlib.Timestamp(timestamp)
+
+	joined, err := t.db.GetJoinedHosts(ctx, receipt.RoomID)
+	if err != nil {
+		log.WithError(err).WithField("room_id", receipt.RoomID).Error("failed to get joined hosts for room")
+		return false
+	}
+
+	names := make([]gomatrixserverlib.ServerName, len(joined))
+	for i := range joined {
+		names[i] = joined[i].ServerName
+	}
+
+	content := map[string]fedTypes.FederationReceiptMRead{}
+	content[receipt.RoomID] = fedTypes.FederationReceiptMRead{
+		User: map[string]fedTypes.FederationReceiptData{
+			receipt.UserID: {
+				Data: fedTypes.ReceiptTS{
+					TS: receipt.Timestamp,
+				},
+				EventIDs: []string{receipt.EventID},
+			},
+		},
+	}
+
+	edu := &gomatrixserverlib.EDU{
+		Type:   gomatrixserverlib.MReceipt,
+		Origin: string(t.ServerName),
+	}
+	if edu.Content, err = json.Marshal(content); err != nil {
+		log.WithError(err).Error("failed to marshal EDU JSON")
+		return true
+	}
+
+	if err := t.queues.SendEDU(edu, t.ServerName, names); err != nil {
+		log.WithError(err).Error("failed to send EDU")
+		return false
+	}
+
+	return true
+}