experimental nip29 support.

nip29/group.go

@@ -0,0 +1,86 @@
+package nip29
+
+import (
+	"fmt"
+
+	"github.com/nbd-wtf/go-nostr"
+)
+
+type Group struct {
+	ID      string
+	Name    string
+	Picture string
+	About   string
+	Members map[string]*Role
+	Private bool
+	Closed  bool
+
+	LastMetadataUpdate nostr.Timestamp
+}
+
+func (group Group) ToMetadataEvent() *nostr.Event {
+	evt := &nostr.Event{
+		Kind:      39000,
+		CreatedAt: group.LastMetadataUpdate,
+		Content:   group.About,
+		Tags: nostr.Tags{
+			nostr.Tag{"d", group.ID},
+		},
+	}
+	if group.Name != "" {
+		evt.Tags = append(evt.Tags, nostr.Tag{"name", group.Name})
+	}
+	if group.About != "" {
+		evt.Tags = append(evt.Tags, nostr.Tag{"about", group.Name})
+	}
+	if group.Picture != "" {
+		evt.Tags = append(evt.Tags, nostr.Tag{"picture", group.Picture})
+	}
+
+	// status
+	if group.Private {
+		evt.Tags = append(evt.Tags, nostr.Tag{"private"})
+	} else {
+		evt.Tags = append(evt.Tags, nostr.Tag{"public"})
+	}
+	if group.Closed {
+		evt.Tags = append(evt.Tags, nostr.Tag{"closed"})
+	} else {
+		evt.Tags = append(evt.Tags, nostr.Tag{"open"})
+	}
+
+	return evt
+}
+
+func (group *Group) MergeInMetadataEvent(evt *nostr.Event) error {
+	if evt.Kind != nostr.KindSimpleGroupMetadata {
+		return fmt.Errorf("expected kind %d, got %d", nostr.KindSimpleGroupMetadata, evt.Kind)
+	}
+
+	if evt.CreatedAt <= group.LastMetadataUpdate {
+		return fmt.Errorf("event is older than our last update (%d vs %d)", evt.CreatedAt, group.LastMetadataUpdate)
+	}
+
+	group.LastMetadataUpdate = evt.CreatedAt
+	group.ID = evt.Tags.GetD()
+	group.Name = group.ID
+
+	if tag := evt.Tags.GetFirst([]string{"name", ""}); tag != nil {
+		group.Name = (*tag)[1]
+	}
+	if tag := evt.Tags.GetFirst([]string{"about", ""}); tag != nil {
+		group.About = (*tag)[1]
+	}
+	if tag := evt.Tags.GetFirst([]string{"picture", ""}); tag != nil {
+		group.Picture = (*tag)[1]
+	}
+
+	if tag := evt.Tags.GetFirst([]string{"private"}); tag != nil {
+		group.Private = true
+	}
+	if tag := evt.Tags.GetFirst([]string{"closed"}); tag != nil {
+		group.Closed = true
+	}
+
+	return nil
+}