nip34: grasp url helper.

nip34/grasp/helpers.go

@@ -0,0 +1,25 @@
+package grasp
+
+import (
+	"net/url"
+	"strings"
+
+	"fiatjaf.com/nostr/nip19"
+)
+
+func IsGraspURL(u string) bool {
+	parsed, err := url.Parse(u)
+	if err != nil {
+		return false
+	}
+
+	if strings.Count(parsed.Path, "/") != 2 || len(parsed.Path) < 65 {
+		return false
+	}
+
+	if prefix, _, err := nip19.Decode(parsed.Path[1:64]); err != nil || prefix != "npub" {
+		return false
+	}
+
+	return true
+}