nip19: decode to pointer.

nip19/pointer.go

@@ -1,6 +1,10 @@
 package nip19
 
-import "github.com/nbd-wtf/go-nostr"
+import (
+	"fmt"
+
+	"github.com/nbd-wtf/go-nostr"
+)
 
 func EncodePointer(pointer nostr.Pointer) string {
 	switch v := pointer.(type) {
@@ -16,3 +20,25 @@ func EncodePointer(pointer nostr.Pointer) string {
 	}
 	return ""
 }
+
+func ToPointer(code string) (nostr.Pointer, error) {
+	prefix, data, err := Decode(code)
+	if err != nil {
+		return nil, err
+	}
+
+	switch prefix {
+	case "npub":
+		return nostr.ProfilePointer{PublicKey: data.(string)}, nil
+	case "nprofile":
+		return data.(nostr.ProfilePointer), nil
+	case "nevent":
+		return data.(nostr.EventPointer), nil
+	case "note":
+		return nostr.EventPointer{ID: data.(string)}, nil
+	case "naddr":
+		return data.(nostr.EntityPointer), nil
+	default:
+		return nil, fmt.Errorf("unexpected prefix '%s' to '%s'", prefix, code)
+	}
+}