nip27 parsing improved (and with nip08 support removed) in its own package.

nip27/references.go

@@ -0,0 +1,78 @@
+package nip27
+
+import (
+	"iter"
+	"regexp"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/nbd-wtf/go-nostr/nip19"
+)
+
+type Reference struct {
+	Text    string
+	Start   int
+	End     int
+	Profile *nostr.ProfilePointer
+	Event   *nostr.EventPointer
+	Entity  *nostr.EntityPointer
+}
+
+var mentionRegex = regexp.MustCompile(`\bnostr:((note|npub|naddr|nevent|nprofile)1\w+)\b`)
+
+func ParseReferences(evt nostr.Event) iter.Seq[Reference] {
+	return func(yield func(Reference) bool) {
+		for _, ref := range mentionRegex.FindAllStringSubmatchIndex(evt.Content, -1) {
+			reference := Reference{
+				Text:  evt.Content[ref[0]:ref[1]],
+				Start: ref[0],
+				End:   ref[1],
+			}
+
+			nip19code := evt.Content[ref[2]:ref[3]]
+
+			if prefix, data, err := nip19.Decode(nip19code); err == nil {
+				switch prefix {
+				case "npub":
+					reference.Profile = &nostr.ProfilePointer{
+						PublicKey: data.(string), Relays: []string{},
+					}
+					tag := evt.Tags.GetFirst([]string{"p", reference.Profile.PublicKey})
+					if tag != nil && len(*tag) >= 3 {
+						reference.Profile.Relays = []string{(*tag)[2]}
+					}
+				case "nprofile":
+					pp := data.(nostr.ProfilePointer)
+					reference.Profile = &pp
+					tag := evt.Tags.GetFirst([]string{"p", reference.Profile.PublicKey})
+					if tag != nil && len(*tag) >= 3 {
+						reference.Profile.Relays = append(reference.Profile.Relays, (*tag)[2])
+					}
+				case "note":
+					// we don't even bother here because people using note1 codes aren't including relay hints anyway
+					reference.Event = &nostr.EventPointer{ID: data.(string), Relays: []string{}}
+				case "nevent":
+					evp := data.(nostr.EventPointer)
+					reference.Event = &evp
+					tag := evt.Tags.GetFirst([]string{"e", reference.Event.ID})
+					if tag != nil && len(*tag) >= 3 {
+						reference.Event.Relays = append(reference.Event.Relays, (*tag)[2])
+						if reference.Event.Author == "" && len(*tag) >= 5 {
+							reference.Event.Author = (*tag)[4]
+						}
+					}
+				case "naddr":
+					addr := data.(nostr.EntityPointer)
+					reference.Entity = &addr
+					tag := evt.Tags.GetFirst([]string{"a", reference.Entity.AsTagReference()})
+					if tag != nil && len(*tag) >= 3 {
+						reference.Entity.Relays = append(reference.Entity.Relays, (*tag)[2])
+					}
+				}
+			}
+
+			if !yield(reference) {
+				return
+			}
+		}
+	}
+}

nip27/references_test.go

@@ -0,0 +1,46 @@
+package nip27
+
+import (
+	"slices"
+	"testing"
+
+	"github.com/nbd-wtf/go-nostr"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParseReferences(t *testing.T) {
+	evt := nostr.Event{
+		Tags: nostr.Tags{
+			{"p", "cc6b9fea033f59c3c39a0407c5f1bfee439b077508d918cfdc0d6fd431d39393", "wss://xawr.com"},
+			{"e", "a84c5de86efc2ec2cff7bad077c4171e09146b633b7ad117fffe088d9579ac33", "wss://other.com", "reply"},
+			{"e", "cc6b9fea033f59c3c39a0407c5f1bfee439b077508d918cfdc0d6fd431d39393", "wss://nasdj.com"},
+		},
+		Content: "hello, nostr:nprofile1qqsvc6ulagpn7kwrcwdqgp797xl7usumqa6s3kgcelwq6m75x8fe8yc5usxdg wrote nostr:nevent1qqsvc6ulagpn7kwrcwdqgp797xl7usumqa6s3kgcelwq6m75x8fe8ychxp5v4!",
+	}
+
+	expected := []Reference{
+		{
+			Text:  "nostr:nprofile1qqsvc6ulagpn7kwrcwdqgp797xl7usumqa6s3kgcelwq6m75x8fe8yc5usxdg",
+			Start: 7,
+			End:   83,
+			Profile: &nostr.ProfilePointer{
+				PublicKey: "cc6b9fea033f59c3c39a0407c5f1bfee439b077508d918cfdc0d6fd431d39393",
+				Relays:    []string{"wss://xawr.com"},
+			},
+		},
+		{
+			Text:  "nostr:nevent1qqsvc6ulagpn7kwrcwdqgp797xl7usumqa6s3kgcelwq6m75x8fe8ychxp5v4",
+			Start: 90,
+			End:   164,
+			Event: &nostr.EventPointer{
+				ID:     "cc6b9fea033f59c3c39a0407c5f1bfee439b077508d918cfdc0d6fd431d39393",
+				Relays: []string{"wss://nasdj.com"},
+				Author: "",
+			},
+		},
+	}
+
+	got := slices.Collect(ParseReferences(evt))
+
+	require.EqualValues(t, expected, got)
+}