relay interface over stores.

relay_interface.go

@@ -0,0 +1,75 @@
+package eventstore
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+// RelayInterface is a wrapper thing that unifies Store and nostr.Relay under a common API.
+type RelayInterface interface {
+	Publish(ctx context.Context, event nostr.Event) (nostr.Status, error)
+	QuerySync(ctx context.Context, filter nostr.Filter, opts ...nostr.SubscriptionOption) ([]*nostr.Event, error)
+}
+
+type RelayWrapper struct {
+	Store
+}
+
+func (w RelayWrapper) Publish(ctx context.Context, evt *nostr.Event) error {
+	if evt == nil {
+		return fmt.Errorf("event is nil")
+	}
+
+	if 20000 <= evt.Kind && evt.Kind < 30000 {
+		// do not store ephemeral events
+		return nil
+	} else if evt.Kind == 0 || evt.Kind == 3 || (10000 <= evt.Kind && evt.Kind < 20000) {
+		// replaceable event, delete before storing
+		ch, err := w.Store.QueryEvents(ctx, nostr.Filter{Authors: []string{evt.PubKey}, Kinds: []int{evt.Kind}})
+		if err != nil {
+			return fmt.Errorf("failed to query before replacing: %w", err)
+		}
+		previous := <-ch
+		if err := w.Store.DeleteEvent(ctx, previous); err != nil {
+			return fmt.Errorf("failed to delete event for replacing: %w", err)
+		}
+	} else if 30000 <= evt.Kind && evt.Kind < 40000 {
+		// parameterized replaceable event, delete before storing
+		d := evt.Tags.GetFirst([]string{"d", ""})
+		if d != nil {
+			ch, err := w.Store.QueryEvents(ctx, nostr.Filter{Authors: []string{evt.PubKey}, Kinds: []int{evt.Kind}, Tags: nostr.TagMap{"d": []string{d.Value()}}})
+			if err != nil {
+				return fmt.Errorf("failed to query before parameterized replacing: %w", err)
+			}
+			previous := <-ch
+			if previous != nil {
+				if err := w.Store.DeleteEvent(ctx, previous); err != nil {
+					return fmt.Errorf("failed to delete event for parameterized replacing: %w", err)
+				}
+			}
+		}
+	}
+
+	return w.SaveEvent(ctx, evt)
+}
+
+func (w RelayWrapper) QuerySync(ctx context.Context, filter nostr.Filter, opts ...nostr.SubscriptionOption) ([]*nostr.Event, error) {
+	ch, err := w.Store.QueryEvents(ctx, filter)
+	if err != nil {
+		return nil, fmt.Errorf("failed to query: %w", err)
+	}
+
+	n := filter.Limit
+	if n == 0 {
+		n = 500
+	}
+
+	results := make([]*nostr.Event, 0, n)
+	for evt := range ch {
+		results = append(results, evt)
+	}
+
+	return results, nil
+}