From 5f8da7d9cddbd1a1b22e54a8c4c36e8e38f3466c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20R=C3=BChl?= <sebastian@mapped.com>
Date: Tue, 29 Aug 2023 09:39:12 +0200
Subject: [PATCH] refactor: more efficient production of nodes from expanded
 node id

---
 client.go     |  7 +++++++
 node.go       | 19 +------------------
 ua/node_id.go | 11 +++++++++++
 3 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/client.go b/client.go
index d0520c72..b8954cd4 100644
--- a/client.go
+++ b/client.go
@@ -962,6 +962,13 @@ func (c *Client) Node(id *ua.NodeID) *Node {
 	return &Node{ID: id, c: c}
 }
 
+// NodeFromExpandedNodeID returns a node object which accesses its attributes
+// through this client connection. This is usually needed when working with node ids returned
+// from browse responses by the server.
+func (c *Client) NodeFromExpandedNodeID(id *ua.ExpandedNodeID) *Node {
+	return &Node{ID: ua.NewNodeIDFromExpandedNodeID(id), c: c}
+}
+
 // FindServers finds the servers available at an endpoint
 func (c *Client) FindServers(ctx context.Context) (*ua.FindServersResponse, error) {
 	stats.Client().Add("FindServers", 1)
diff --git a/node.go b/node.go
index 6e172c7e..2d083297 100644
--- a/node.go
+++ b/node.go
@@ -6,7 +6,6 @@ package opcua
 
 import (
 	"context"
-	"encoding/base64"
 	"strings"
 
 	"github.com/gopcua/opcua/id"
@@ -161,23 +160,7 @@ func (n *Node) ReferencedNodes(ctx context.Context, refs uint32, dir ua.BrowseDi
 		return nil, err
 	}
 	for _, r := range res {
-		nodeID := r.NodeID.NodeID
-		switch nodeID.Type() {
-		case ua.NodeIDTypeTwoByte:
-			nodeID = ua.NewTwoByteNodeID(uint8(nodeID.IntID()))
-		case ua.NodeIDTypeFourByte:
-			nodeID = ua.NewFourByteNodeID(uint8(nodeID.Namespace()), uint16(nodeID.IntID()))
-		case ua.NodeIDTypeNumeric:
-			nodeID = ua.NewNumericNodeID(nodeID.Namespace(), nodeID.IntID())
-		case ua.NodeIDTypeString:
-			nodeID = ua.NewStringNodeID(nodeID.Namespace(), nodeID.StringID())
-		case ua.NodeIDTypeGUID:
-			nodeID = ua.NewGUIDNodeID(nodeID.Namespace(), nodeID.String())
-		case ua.NodeIDTypeByteString:
-			bytes, _ := base64.StdEncoding.DecodeString(nodeID.String())
-			nodeID = ua.NewByteStringNodeID(nodeID.Namespace(), bytes)
-		}
-		nodes = append(nodes, n.c.Node(nodeID))
+		nodes = append(nodes, n.c.NodeFromExpandedNodeID(r.NodeID))
 	}
 	return nodes, nil
 }
diff --git a/ua/node_id.go b/ua/node_id.go
index 594829d3..9fdb8f2b 100644
--- a/ua/node_id.go
+++ b/ua/node_id.go
@@ -78,6 +78,17 @@ func NewByteStringNodeID(ns uint16, id []byte) *NodeID {
 	}
 }
 
+// NewNodeIDFromExpandedNodeID returns a new NodeID derived from ExpandedNodeID
+func NewNodeIDFromExpandedNodeID(id *ExpandedNodeID) *NodeID {
+	return &NodeID{
+		mask: id.NodeID.mask & 0b00111111, // expanded flag NamespaceURI and ServerIndex need to be unset
+		ns:   id.NodeID.ns,
+		nid:  id.NodeID.nid,
+		bid:  id.NodeID.bid,
+		gid:  id.NodeID.gid,
+	}
+}
+
 // MustParseNodeID returns a node id from a string definition
 // if it is parseable by ParseNodeID. Otherwise, the function
 // panics.