refactor: clean up NodeService interface; move all integrity logic behind it

cmd/rel.go

@@ -7,13 +7,10 @@ import (
 	"strings"
 )
 
-func parseRelFlag(svc service.NodeService, s string) (*models.Rel, error) {
+// parseRelInput parses a "type:target" string into a RelInput.
+func parseRelInput(s string) (service.RelInput, error) {
 	if p := strings.SplitN(s, ":", 2); len(p) == 2 {
-		return &models.Rel{Type: models.RelType(p[0]), Target: p[1]}, nil
+		return service.RelInput{Type: models.RelType(p[0]), Target: p[1]}, nil
 	}
-
-	// name resolution for rels
-	//TODO:
-
-	return &models.Rel{}, fmt.Errorf("invalid relation format: %s (expected type:id)", s)
+	return service.RelInput{}, fmt.Errorf("invalid relation format: %s (expected type:target)", s)
 }