Implement read receipts (#1528)

* fix conversion from int to string yields a string of one rune, not a string of digits

* Add receipts table to syncapi

* Use StreamingToken as the since value

* Add required method to testEDUProducer

* Make receipt json creation "easier" to read

* Add receipts api to the eduserver

* Add receipts endpoint

* Add eduserver kafka consumer

* Add missing kafka config

* Add passing tests to whitelist

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Fix copy & paste error

* Fix column count error

* Make outbound federation receipts pass

* Make "Inbound federation rejects receipts from wrong remote" pass

* Don't use errors package

* - Add TODO for batching requests
- Rename variable

* Return a better error message

* - Use OutputReceiptEvent instead of InputReceiptEvent as result
- Don't use the errors package for errors
- Defer CloseAndLogIfError to close rows
- Fix Copyright

* Better creation/usage of JoinResponse

* Query all joined rooms instead of just one

* Update gomatrixserverlib

* Add sqlite3 migration

* Add postgres migration

* Ensure required sequence exists before running migrations

* Clarification on comment

* - Fix a bug when creating client receipts
- Use concrete types instead of interface{}

* Remove dead code
Use key for timestamp

* Fix postgres query...

* Remove single purpose struct

* Use key/value directly

* Only apply receipts on initial sync or if edu positions differ,
otherwise we'll be sending the same receipts over and over again.

* Actually update the id, so it is correctly send in syncs

* Set receipt on request to /read_markers

* Fix issue with receipts getting overwritten

* Use fmt.Errorf instead of pkg/errors

* Revert "Add postgres migration"

This reverts commit 722fe5a04628882b787d096942459961db159b06.

* Revert "Add sqlite3 migration"

This reverts commit d113b03f6495a4b8f8bcf158a3d00b510b4240cc.

* Fix selectRoomReceipts query

* Make golangci-lint happy

Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>

7 files changed, 137 insertions, 2 deletions

diff --git a/eduserver/api/input.go b/eduserver/api/input.go
index 0d0d21f3..f8599e1c 100644
--- a/eduserver/api/input.go
+++ b/eduserver/api/input.go
@@ -59,6 +59,22 @@ type InputSendToDeviceEventRequest struct {
 // InputSendToDeviceEventResponse is a response to InputSendToDeviceEventRequest
 type InputSendToDeviceEventResponse struct{}
 
+type InputReceiptEvent struct {
+	UserID    string                      `json:"user_id"`
+	RoomID    string                      `json:"room_id"`
+	EventID   string                      `json:"event_id"`
+	Type      string                      `json:"type"`
+	Timestamp gomatrixserverlib.Timestamp `json:"timestamp"`
+}
+
+// InputReceiptEventRequest is a request to EDUServerInputAPI
+type InputReceiptEventRequest struct {
+	InputReceiptEvent InputReceiptEvent `json:"input_receipt_event"`
+}
+
+// InputReceiptEventResponse is a response to InputReceiptEventRequest
+type InputReceiptEventResponse struct{}
+
 // EDUServerInputAPI is used to write events to the typing server.
 type EDUServerInputAPI interface {
 	InputTypingEvent(
@@ -72,4 +88,10 @@ type EDUServerInputAPI interface {
 		request *InputSendToDeviceEventRequest,
 		response *InputSendToDeviceEventResponse,
 	) error
+
+	InputReceiptEvent(
+		ctx context.Context,
+		request *InputReceiptEventRequest,
+		response *InputReceiptEventResponse,
+	) error
 }
diff --git a/eduserver/api/output.go b/eduserver/api/output.go
index e6ded841..650458a2 100644
--- a/eduserver/api/output.go
+++ b/eduserver/api/output.go
@@ -49,3 +49,39 @@ type OutputSendToDeviceEvent struct {
 	DeviceID string `json:"device_id"`
 	gomatrixserverlib.SendToDeviceEvent
 }
+
+type ReceiptEvent struct {
+	UserID    string                      `json:"user_id"`
+	RoomID    string                      `json:"room_id"`
+	EventID   string                      `json:"event_id"`
+	Type      string                      `json:"type"`
+	Timestamp gomatrixserverlib.Timestamp `json:"timestamp"`
+}
+
+// OutputReceiptEvent is an entry in the receipt output kafka log
+type OutputReceiptEvent struct {
+	UserID    string                      `json:"user_id"`
+	RoomID    string                      `json:"room_id"`
+	EventID   string                      `json:"event_id"`
+	Type      string                      `json:"type"`
+	Timestamp gomatrixserverlib.Timestamp `json:"timestamp"`
+}
+
+// Helper structs for receipts json creation
+type ReceiptMRead struct {
+	User map[string]ReceiptTS `json:"m.read"`
+}
+
+type ReceiptTS struct {
+	TS gomatrixserverlib.Timestamp `json:"ts"`
+}
+
+// FederationSender output
+type FederationReceiptMRead struct {
+	User map[string]FederationReceiptData `json:"m.read"`
+}
+
+type FederationReceiptData struct {
+	Data     ReceiptTS `json:"data"`
+	EventIDs []string  `json:"event_ids"`
+}
diff --git a/eduserver/api/wrapper.go b/eduserver/api/wrapper.go
index c2c4596d..7907f4d3 100644
--- a/eduserver/api/wrapper.go
+++ b/eduserver/api/wrapper.go
@@ -67,3 +67,22 @@ func SendToDevice(
 	response := InputSendToDeviceEventResponse{}
 	return eduAPI.InputSendToDeviceEvent(ctx, &request, &response)
 }
+
+// SendReceipt sends a receipt event to EDU Server
+func SendReceipt(
+	ctx context.Context,
+	eduAPI EDUServerInputAPI, userID, roomID, eventID, receiptType string,
+	timestamp gomatrixserverlib.Timestamp,
+) error {
+	request := InputReceiptEventRequest{
+		InputReceiptEvent: InputReceiptEvent{
+			UserID:    userID,
+			RoomID:    roomID,
+			EventID:   eventID,
+			Type:      receiptType,
+			Timestamp: timestamp,
+		},
+	}
+	response := InputReceiptEventResponse{}
+	return eduAPI.InputReceiptEvent(ctx, &request, &response)
+}
diff --git a/eduserver/eduserver.go b/eduserver/eduserver.go
index 098ac024..d5ab3681 100644
--- a/eduserver/eduserver.go
+++ b/eduserver/eduserver.go
@@ -49,8 +49,9 @@ func NewInternalAPI(
 		Cache:                        eduCache,
 		UserAPI:                      userAPI,
 		Producer:                     producer,
-		OutputTypingEventTopic:       string(cfg.Matrix.Kafka.TopicFor(config.TopicOutputTypingEvent)),
-		OutputSendToDeviceEventTopic: string(cfg.Matrix.Kafka.TopicFor(config.TopicOutputSendToDeviceEvent)),
+		OutputTypingEventTopic:       cfg.Matrix.Kafka.TopicFor(config.TopicOutputTypingEvent),
+		OutputSendToDeviceEventTopic: cfg.Matrix.Kafka.TopicFor(config.TopicOutputSendToDeviceEvent),
+		OutputReceiptEventTopic:      cfg.Matrix.Kafka.TopicFor(config.TopicOutputReceiptEvent),
 		ServerName:                   cfg.Matrix.ServerName,
 	}
 }
diff --git a/eduserver/input/input.go b/eduserver/input/input.go
index e3d2c55e..c54fb9de 100644
--- a/eduserver/input/input.go
+++ b/eduserver/input/input.go
@@ -37,6 +37,8 @@ type EDUServerInputAPI struct {
 	OutputTypingEventTopic string
 	// The kafka topic to output new send to device events to.
 	OutputSendToDeviceEventTopic string
+	// The kafka topic to output new receipt events to
+	OutputReceiptEventTopic string
 	// kafka producer
 	Producer sarama.SyncProducer
 	// Internal user query API
@@ -173,3 +175,31 @@ func (t *EDUServerInputAPI) sendToDeviceEvent(ise *api.InputSendToDeviceEvent) e
 
 	return nil
 }
+
+// InputReceiptEvent implements api.EDUServerInputAPI
+// TODO: Intelligently batch requests sent by the same user (e.g wait a few milliseconds before emitting output events)
+func (t *EDUServerInputAPI) InputReceiptEvent(
+	ctx context.Context,
+	request *api.InputReceiptEventRequest,
+	response *api.InputReceiptEventResponse,
+) error {
+	logrus.WithFields(logrus.Fields{}).Infof("Producing to topic '%s'", t.OutputReceiptEventTopic)
+	output := &api.OutputReceiptEvent{
+		UserID:    request.InputReceiptEvent.UserID,
+		RoomID:    request.InputReceiptEvent.RoomID,
+		EventID:   request.InputReceiptEvent.EventID,
+		Type:      request.InputReceiptEvent.Type,
+		Timestamp: request.InputReceiptEvent.Timestamp,
+	}
+	js, err := json.Marshal(output)
+	if err != nil {
+		return err
+	}
+	m := &sarama.ProducerMessage{
+		Topic: t.OutputReceiptEventTopic,
+		Key:   sarama.StringEncoder(request.InputReceiptEvent.RoomID + ":" + request.InputReceiptEvent.UserID),
+		Value: sarama.ByteEncoder(js),
+	}
+	_, _, err = t.Producer.SendMessage(m)
+	return err
+}
diff --git a/eduserver/inthttp/client.go b/eduserver/inthttp/client.go
index 7d0bc160..0690ed82 100644
--- a/eduserver/inthttp/client.go
+++ b/eduserver/inthttp/client.go
@@ -14,6 +14,7 @@ import (
 const (
 	EDUServerInputTypingEventPath       = "/eduserver/input"
 	EDUServerInputSendToDeviceEventPath = "/eduserver/sendToDevice"
+	EDUServerInputReceiptEventPath      = "/eduserver/receipt"
 )
 
 // NewEDUServerClient creates a EDUServerInputAPI implemented by talking to a HTTP POST API.
@@ -54,3 +55,16 @@ func (h *httpEDUServerInputAPI) InputSendToDeviceEvent(
 	apiURL := h.eduServerURL + EDUServerInputSendToDeviceEventPath
 	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
 }
+
+// InputSendToDeviceEvent implements EDUServerInputAPI
+func (h *httpEDUServerInputAPI) InputReceiptEvent(
+	ctx context.Context,
+	request *api.InputReceiptEventRequest,
+	response *api.InputReceiptEventResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "InputReceiptEventPath")
+	defer span.Finish()
+
+	apiURL := h.eduServerURL + EDUServerInputReceiptEventPath
+	return httputil.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}
diff --git a/eduserver/inthttp/server.go b/eduserver/inthttp/server.go
index e374513a..a3494375 100644
--- a/eduserver/inthttp/server.go
+++ b/eduserver/inthttp/server.go
@@ -38,4 +38,17 @@ func AddRoutes(t api.EDUServerInputAPI, internalAPIMux *mux.Router) {
 			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
 		}),
 	)
+	internalAPIMux.Handle(EDUServerInputReceiptEventPath,
+		httputil.MakeInternalAPI("inputReceiptEvent", func(req *http.Request) util.JSONResponse {
+			var request api.InputReceiptEventRequest
+			var response api.InputReceiptEventResponse
+			if err := json.NewDecoder(req.Body).Decode(&request); err != nil {
+				return util.MessageResponse(http.StatusBadRequest, err.Error())
+			}
+			if err := t.InputReceiptEvent(req.Context(), &request, &response); err != nil {
+				return util.ErrorResponse(err)
+			}
+			return util.JSONResponse{Code: http.StatusOK, JSON: &response}
+		}),
+	)
 }