From f43fdfcca36c189dfada59bc0a871dd76682a732 Mon Sep 17 00:00:00 2001
From: Hylke Visser <hylke@thethingsindustries.com>
Date: Fri, 8 Oct 2021 10:36:59 +0200
Subject: [PATCH] Add set-eui-as-id flag to re-map DeviceID to DevEUI

---
 CHANGELOG.md |  2 ++
 cmd/root.go  |  2 ++
 cmd/util.go  | 18 +++++++++++++++---
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 991f3a9..eb89459 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Added
 
+- `--set-eui-as-id` flag to re-map the ID of end devices. Using this flag will set the device ID to the DevEUI (if it has a DevEUI). When combined with the `--dev-id-prefix` flag, the ID will consist of the prefix and the DevEUI.
+
 ### Changed
 
 ### Fixed
diff --git a/cmd/root.go b/cmd/root.go
index 76d52cc..91d83a2 100644
--- a/cmd/root.go
+++ b/cmd/root.go
@@ -48,6 +48,7 @@ var (
 			ctx = log.NewContext(context.Background(), logger)
 
 			exportCfg.devIDPrefix, _ = cmd.Flags().GetString("dev-id-prefix")
+			exportCfg.euiForID, _ = cmd.Flags().GetBool("set-eui-as-id")
 
 			rpclog.ReplaceGrpcLogger(logger)
 			return nil
@@ -68,5 +69,6 @@ func init() {
 	rootCmd.PersistentFlags().Bool("verbose", false, "Verbose output")
 	rootCmd.PersistentFlags().Bool("dry-run", false, "Do everything except resetting root and session keys of exported devices")
 	rootCmd.PersistentFlags().String("frequency-plans-url", "https://raw.githubusercontent.com/TheThingsNetwork/lorawan-frequency-plans/master", "URL for fetching frequency plans")
+	rootCmd.PersistentFlags().Bool("set-eui-as-id", false, "Use the DevEUI as ID")
 	rootCmd.PersistentFlags().String("dev-id-prefix", "", "(optional) value to be prefixed to the resulting device IDs")
 }
diff --git a/cmd/util.go b/cmd/util.go
index 4e04419..816f460 100644
--- a/cmd/util.go
+++ b/cmd/util.go
@@ -46,6 +46,7 @@ var (
 )
 
 type exportConfig struct {
+	euiForID    bool
 	devIDPrefix string
 }
 
@@ -54,17 +55,28 @@ func (cfg exportConfig) exportDev(s source.Source, devID string) error {
 	if err != nil {
 		return errExport.WithAttributes("device_id", devID).WithCause(err)
 	}
+	oldID := dev.DeviceId
+
+	if cfg.euiForID && dev.DevEui != nil {
+		dev.DeviceId = strings.ToLower(dev.DevEui.String())
+	}
 	if cfg.devIDPrefix != "" {
 		dev.DeviceId = fmt.Sprintf("%s-%s", cfg.devIDPrefix, dev.DeviceId)
 	}
-	// V3 does not allow any underscores in identifiers
-	dev.DeviceId = sanitizeID.Replace(dev.DeviceId)
-	dev.ApplicationId = sanitizeID.Replace(dev.ApplicationId)
 
+	dev.DeviceId = sanitizeID.Replace(dev.DeviceId)
 	if len(dev.DeviceId) > maxIDLength {
 		return errDevIDExceedsMaxLength.WithAttributes("id", dev.DeviceId)
 	}
 
+	if dev.DeviceId != oldID {
+		if dev.Attributes == nil {
+			dev.Attributes = make(map[string]string)
+		}
+		dev.Attributes["old-id"] = oldID
+	}
+
+	dev.ApplicationId = sanitizeID.Replace(dev.ApplicationId)
 	if len(dev.ApplicationId) > maxIDLength {
 		return errAppIDExceedsMaxLength.WithAttributes("id", dev.ApplicationId)
 	}