From c91488d2fe13b50e1e8a7f3fb61943e5d34e824e Mon Sep 17 00:00:00 2001
From: proddy <paul@derbyshire.nl>
Date: Sun, 26 Jul 2026 11:16:10 +0200
Subject: [PATCH] cz -> cs

---
 interface/src/App.tsx                                | 2 +-
 interface/src/app/settings/ApplicationSettings.tsx   | 2 +-
 interface/src/components/inputs/LanguageSelector.tsx | 4 ++--
 interface/src/i18n/{CZ.svg => CS.svg}                | 0
 interface/src/i18n/{cz => cs}/index.ts               | 4 ++--
 src/core/helpers.cpp                                 | 2 +-
 src/core/locale_translations.h                       | 4 ++--
 src/core/system.cpp                                  | 7 ++++++-
 8 files changed, 15 insertions(+), 10 deletions(-)
 rename interface/src/i18n/{CZ.svg => CS.svg} (100%)
 rename interface/src/i18n/{cz => cs}/index.ts (99%)

diff --git a/interface/src/App.tsx b/interface/src/App.tsx
index 8db9f2f28..0341dc9e6 100644
--- a/interface/src/App.tsx
+++ b/interface/src/App.tsx
@@ -20,7 +20,7 @@ const ALL_LOCALES = [
   'sk',
   'sv',
   'tr',
-  'cz'
+  'cs'
 ] as Locales[];
 
 // Optional build-time allow-list (e.g. VITE_APP_LOCALES="en,de,nl"). When unset,
diff --git a/interface/src/app/settings/ApplicationSettings.tsx b/interface/src/app/settings/ApplicationSettings.tsx
index 9f2a63819..44e3a0fb0 100644
--- a/interface/src/app/settings/ApplicationSettings.tsx
+++ b/interface/src/app/settings/ApplicationSettings.tsx
@@ -548,7 +548,7 @@ const ApplicationSettings = () => {
               margin="normal"
               select
             >
-              <MenuItem value="cz">Česky (CZ)</MenuItem>
+              <MenuItem value="cs">Česky (CZ)</MenuItem>
               <MenuItem value="de">Deutsch (DE)</MenuItem>
               <MenuItem value="en">English (EN)</MenuItem>
               <MenuItem value="fr">Français (FR)</MenuItem>
diff --git a/interface/src/components/inputs/LanguageSelector.tsx b/interface/src/components/inputs/LanguageSelector.tsx
index 3eb5b59a4..f96192fa6 100644
--- a/interface/src/components/inputs/LanguageSelector.tsx
+++ b/interface/src/components/inputs/LanguageSelector.tsx
@@ -4,7 +4,7 @@ import type { CSSProperties } from 'react';
 
 import { MenuItem, TextField } from '@mui/material';
 
-import CZflag from 'i18n/CZ.svg';
+import CSflag from 'i18n/CS.svg';
 import DEflag from 'i18n/DE.svg';
 import FRflag from 'i18n/FR.svg';
 import GBflag from 'i18n/GB.svg';
@@ -28,7 +28,7 @@ interface LanguageOption {
 }
 
 const LANGUAGE_OPTIONS: LanguageOption[] = [
-  { key: 'cz', flag: CZflag, label: 'CZ' },
+  { key: 'cs', flag: CSflag, label: 'CS' },
   { key: 'de', flag: DEflag, label: 'DE' },
   { key: 'en', flag: GBflag, label: 'EN' },
   { key: 'fr', flag: FRflag, label: 'FR' },
diff --git a/interface/src/i18n/CZ.svg b/interface/src/i18n/CS.svg
similarity index 100%
rename from interface/src/i18n/CZ.svg
rename to interface/src/i18n/CS.svg
diff --git a/interface/src/i18n/cz/index.ts b/interface/src/i18n/cs/index.ts
similarity index 99%
rename from interface/src/i18n/cz/index.ts
rename to interface/src/i18n/cs/index.ts
index 07f534e64..85f203421 100644
--- a/interface/src/i18n/cz/index.ts
+++ b/interface/src/i18n/cs/index.ts
@@ -1,6 +1,6 @@
 import type { Translation } from '../i18n-types';
 
-const cz: Translation = {
+const cs: Translation = {
   LANGUAGE: 'Jazyk',
   RETRY: 'Zkusit znovu',
   LOADING: 'Načítání',
@@ -370,4 +370,4 @@ const cz: Translation = {
   EXECUTE_COMMAND_SENT: 'Příkaz odeslán',
 };
 
-export default cz;
+export default cs;
diff --git a/src/core/helpers.cpp b/src/core/helpers.cpp
index 62186fb3b..9e10c034f 100644
--- a/src/core/helpers.cpp
+++ b/src/core/helpers.cpp
@@ -814,7 +814,7 @@ std::string Helpers::toUpper(std::string const & s) {
 
 // capitalizes one UTF-8 character in char array
 // works with Latin1 (1 byte), Polish and other (2 bytes) characters
-// supports special characters for all 11 supported languages: EN, DE, NL, SV, PL, NO, FR, TR, IT, SK, CZ
+// supports special characters for all 11 supported languages: EN, DE, NL, SV, PL, NO, FR, TR, IT, SK, CS
 #if defined(EMSESP_STANDALONE)
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wtype-limits"
diff --git a/src/core/locale_translations.h b/src/core/locale_translations.h
index f5ece66ac..b96084df9 100644
--- a/src/core/locale_translations.h
+++ b/src/core/locale_translations.h
@@ -30,9 +30,9 @@
 #define EMSESP_LOCALE_TR "tr"
 #define EMSESP_LOCALE_IT "it"
 #define EMSESP_LOCALE_SK "sk"
-#define EMSESP_LOCALE_CZ "cz"
+#define EMSESP_LOCALE_CS "cs"
 
-// IMPORTANT! translations are in the order: en, de, nl, sv, pl, no, fr, tr, it, sk, cz
+// IMPORTANT! translations are in the order: en, de, nl, sv, pl, no, fr, tr, it, sk, cs
 //
 // if there is no translation, it will default to en
 
diff --git a/src/core/system.cpp b/src/core/system.cpp
index 97d90a487..b73eae0d1 100644
--- a/src/core/system.cpp
+++ b/src/core/system.cpp
@@ -71,7 +71,7 @@ const char * const languages[] = {EMSESP_LOCALE_EN,
                                   EMSESP_LOCALE_TR,
                                   EMSESP_LOCALE_IT,
                                   EMSESP_LOCALE_SK,
-                                  EMSESP_LOCALE_CZ};
+                                  EMSESP_LOCALE_CS};
 #endif
 
 static constexpr uint8_t NUM_LANGUAGES = sizeof(languages) / sizeof(const char *);
@@ -1632,6 +1632,11 @@ bool System::check_upgrade() {
                     return StateUpdateResult::CHANGED;
                 }
             }
+            // Migrate language from cz to cs
+            if (settings.locale == "cz") {
+                settings.locale = "cs";
+                return StateUpdateResult::CHANGED;
+            }
             return StateUpdateResult::UNCHANGED;
         });
     } else if (this_version < settings_version) {