Publish selected event kinds to relay.nos.social (#30)

The idea is to make it work like https://purplepag.es/what.

service/app/app.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/boreq/errors"
 	"github.com/planetary-social/nos-event-service/service/domain"
+	"github.com/planetary-social/nos-event-service/service/domain/relays"
 )
 
 var (
@@ -121,3 +122,8 @@ type ContactsExtractor interface {
 type Subscriber interface {
 	EventSavedQueueLength(ctx context.Context) (int, error)
 }
+
+type RelayConnections interface {
+	GetEvents(ctx context.Context, relayAddress domain.RelayAddress, filter domain.Filter) (<-chan relays.EventOrEndOfSavedEvents, error)
+	SendEvent(ctx context.Context, relayAddress domain.RelayAddress, event domain.Event) error
+}

service/app/downloader.go

@@ -10,7 +10,6 @@ import (
 	"github.com/planetary-social/nos-event-service/internal"
 	"github.com/planetary-social/nos-event-service/internal/logging"
 	"github.com/planetary-social/nos-event-service/service/domain"
-	"github.com/planetary-social/nos-event-service/service/domain/relays"
 )
 
 const (
@@ -42,10 +41,6 @@ type RelaySource interface {
 	GetRelays(ctx context.Context) ([]domain.RelayAddress, error)
 }
 
-type RelayConnections interface {
-	GetEvents(ctx context.Context, relayAddress domain.RelayAddress, filter domain.Filter) (<-chan relays.EventOrEndOfSavedEvents, error)
-}
-
 type PublicKeySource interface {
 	GetPublicKeys(ctx context.Context) ([]domain.PublicKey, error)
 }

service/app/filter.go

@@ -0,0 +1,54 @@
+package app
+
+import (
+	"time"
+
+	"github.com/planetary-social/nos-event-service/service/domain"
+)
+
+type EventFilter struct {
+	filterNewerThan        *time.Duration
+	filterOlderThan        *time.Duration
+	filterLargerThan       *int
+	filterWithMoreTagsThan *int
+}
+
+func NewEventFilter(
+	filterNewerThan *time.Duration,
+	filterOlderThan *time.Duration,
+	filterLargerThan *int,
+	filterWithMoreTagsThan *int,
+) *EventFilter {
+	return &EventFilter{
+		filterNewerThan:        filterNewerThan,
+		filterOlderThan:        filterOlderThan,
+		filterLargerThan:       filterLargerThan,
+		filterWithMoreTagsThan: filterWithMoreTagsThan,
+	}
+}
+
+func (f EventFilter) IsOk(event domain.Event) bool {
+	if f.filterOlderThan != nil {
+		maxPastAllowed := time.Now().Add(-*f.filterOlderThan)
+		if event.CreatedAt().Before(maxPastAllowed) {
+			return false
+		}
+	}
+
+	if f.filterNewerThan != nil {
+		maxFutureAllowed := time.Now().Add(*f.filterNewerThan)
+		if event.CreatedAt().After(maxFutureAllowed) {
+			return false
+		}
+	}
+
+	if f.filterLargerThan != nil && len(event.Raw()) > *f.filterLargerThan {
+		return false
+	}
+
+	if f.filterWithMoreTagsThan != nil && len(event.Tags()) > *f.filterWithMoreTagsThan {
+		return false
+	}
+
+	return true
+}

service/app/handler_process_saved_event.go

@@ -2,10 +2,28 @@ package app
 
 import (
 	"context"
+	"time"
 
 	"github.com/boreq/errors"
+	"github.com/planetary-social/nos-event-service/internal"
 	"github.com/planetary-social/nos-event-service/internal/logging"
 	"github.com/planetary-social/nos-event-service/service/domain"
+	"github.com/planetary-social/nos-event-service/service/domain/relays"
+)
+
+var (
+	nosRelayAddress                    = domain.MustNewRelayAddress("wss://relay.nos.social")
+	eventKindsWhichShouldBeSentToRelay = internal.NewSetVariadic(
+		domain.EventKindMetadata,
+		domain.EventKindContacts,
+		domain.EventKindRelayListMetadata,
+	)
+	pushToRelayFilter = NewEventFilter(
+		internal.Pointer(900*time.Second),
+		nil,
+		internal.Pointer(65536),
+		internal.Pointer(1024),
+	)
 )
 
 type ProcessSavedEvent struct {
@@ -21,6 +39,7 @@ type ProcessSavedEventHandler struct {
 	relaysExtractor        RelaysExtractor
 	contactsExtractor      ContactsExtractor
 	externalEventPublisher ExternalEventPublisher
+	relayConnections       RelayConnections
 	logger                 logging.Logger
 	metrics                Metrics
 }
@@ -30,6 +49,7 @@ func NewProcessSavedEventHandler(
 	relaysExtractor RelaysExtractor,
 	contactsExtractor ContactsExtractor,
 	externalEventPublisher ExternalEventPublisher,
+	relayConnections RelayConnections,
 	logger logging.Logger,
 	metrics Metrics,
 ) *ProcessSavedEventHandler {
@@ -38,6 +58,7 @@ func NewProcessSavedEventHandler(
 		relaysExtractor:        relaysExtractor,
 		contactsExtractor:      contactsExtractor,
 		externalEventPublisher: externalEventPublisher,
+		relayConnections:       relayConnections,
 		logger:                 logger.New("processSavedEventHandler"),
 		metrics:                metrics,
 	}
@@ -59,6 +80,10 @@ func (h *ProcessSavedEventHandler) Handle(ctx context.Context, cmd ProcessSavedE
 		return errors.Wrap(err, "error publishing the external event")
 	}
 
+	if err := h.maybeSendEventToRelay(ctx, event); err != nil {
+		return errors.Wrapf(err, "error sending the event '%s' to relay", event.Id().Hex())
+	}
+
 	return nil
 }
 
@@ -138,3 +163,36 @@ func (h *ProcessSavedEventHandler) shouldReplaceContacts(ctx context.Context, ad
 
 	return domain.ShouldReplaceContactsEvent(oldEvent, newEvent)
 }
+
+func (h *ProcessSavedEventHandler) maybeSendEventToRelay(ctx context.Context, event domain.Event) error {
+	if !eventKindsWhichShouldBeSentToRelay.Contains(event.Kind()) {
+		return nil
+	}
+
+	if !pushToRelayFilter.IsOk(event) {
+		return nil
+	}
+
+	if err := h.relayConnections.SendEvent(ctx, nosRelayAddress, event); err != nil {
+		if h.shouldDisregardSendEventErr(err) {
+			return nil
+		}
+		return errors.Wrap(err, "error sending event to relay")
+	}
+
+	return nil
+}
+
+func (h *ProcessSavedEventHandler) shouldDisregardSendEventErr(err error) bool {
+	var okResponseErr relays.OKResponseError
+	if errors.As(err, &okResponseErr) {
+		switch okResponseErr.Reason() {
+		case "replaced: have newer event":
+			return true
+		default:
+			return false
+		}
+	}
+
+	return false
+}

service/app/handler_save_received_event.go

@@ -2,12 +2,23 @@ package app
 
 import (
 	"context"
+	"time"
 
 	"github.com/boreq/errors"
+	"github.com/planetary-social/nos-event-service/internal"
 	"github.com/planetary-social/nos-event-service/internal/logging"
 	"github.com/planetary-social/nos-event-service/service/domain"
 )
 
+var (
+	saveFilter = NewEventFilter(
+		internal.Pointer(12*time.Hour),
+		nil,
+		internal.Pointer(1*1000*1000),
+		internal.Pointer(10000),
+	)
+)
+
 type SaveReceivedEvent struct {
 	relay domain.RelayAddress
 	event domain.Event
@@ -46,6 +57,10 @@ func (h *SaveReceivedEventHandler) Handle(ctx context.Context, cmd SaveReceivedE
 		WithField("event.kind", cmd.event.Kind().Int()).
 		Message("saving received event")
 
+	if !saveFilter.IsOk(cmd.event) {
+		return nil
+	}
+
 	if err := h.transactionProvider.Transact(ctx, func(ctx context.Context, adapters Adapters) error {
 		exists, err := h.eventAlreadyExists(ctx, adapters, cmd.event)
 		if err != nil {