From f420c38a32261a0eb07cc29278de3ce044a5ff17 Mon Sep 17 00:00:00 2001
From: Rostyslav Nihrutsa <RostyslavNihrutsa@users.noreply.github.com>
Date: Fri, 16 Jan 2026 15:53:49 +0200
Subject: [PATCH] refactor(Locale): streamline language detection and
 normalization logic

---
 src/cli/builders/locale/LocaleBuilder.ts | 11 ++----
 src/locale/providers/NativeLocale.ts     | 45 ++++++++++++------------
 src/locale/utils.ts                      | 11 ++++++
 3 files changed, 35 insertions(+), 32 deletions(-)

diff --git a/src/cli/builders/locale/LocaleBuilder.ts b/src/cli/builders/locale/LocaleBuilder.ts
index b1ef72b7..e9fdcd58 100644
--- a/src/cli/builders/locale/LocaleBuilder.ts
+++ b/src/cli/builders/locale/LocaleBuilder.ts
@@ -43,15 +43,8 @@ export default class LocaleBuilder implements LocaleBuilderContract {
             }
         }
 
-        if (this.browser === Browser.Opera) {
-            /**
-             * The Opera browser does not support RTL languages,
-             * and for Opera you need to directly indicate what kind of language it is.
-             * interface language is always different
-             */
-
-            items.set(LocaleCustomKeyForLanguage, this.language);
-        }
+        // To accurately determine the language that the browser has detected
+        items.set(LocaleCustomKeyForLanguage, this.language);
 
         return (this.items = items);
     }
diff --git a/src/locale/providers/NativeLocale.ts b/src/locale/providers/NativeLocale.ts
index c3624977..c621d8ee 100644
--- a/src/locale/providers/NativeLocale.ts
+++ b/src/locale/providers/NativeLocale.ts
@@ -1,13 +1,10 @@
-import {getI18nMessage, getI18nUILanguage} from "@addon-core/browser";
+import {getI18nMessage} from "@addon-core/browser";
 
 import AbstractLocale from "./AbstractLocale";
 
-import {convertLocaleKey} from "@locale/utils";
+import {convertLocaleKey, normalizeLocale} from "@locale/utils";
 
-import {isBrowser} from "@main/env";
-
-import {Language, LanguageCodes, LocaleCustomKeyForLanguage, LocaleProvider, LocaleStructure} from "@typing/locale";
-import {Browser} from "@typing/browser";
+import {Language, LocaleCustomKeyForLanguage, LocaleProvider, LocaleStructure} from "@typing/locale";
 
 export interface LocaleNativeStructure extends LocaleStructure {}
 
@@ -18,29 +15,31 @@ export default class NativeLocale extends AbstractLocale<LocaleNativeStructure>
         return (NativeLocale.instance ??= new NativeLocale());
     }
 
-    public lang(): Language {
-        let lang: Language | undefined;
-
-        /**
-         * The Opera browser does not support RTL languages,
-         * and for Opera you need to directly indicate what kind of language it is.
-         * interface language is always different
-         */
-        if (isBrowser(Browser.Opera)) {
-            lang = getI18nMessage(LocaleCustomKeyForLanguage) as Language;
-
-            if (LanguageCodes.has(lang)) {
-                return lang;
-            }
-        }
+    private readonly language?: Language;
 
-        lang = getI18nUILanguage() as Language;
+    constructor() {
+        super();
+
+        const localeLang = getI18nMessage(LocaleCustomKeyForLanguage);
+        const lang = normalizeLocale(localeLang);
 
         if (!lang) {
+            console.warn(`Locale Native: Language "${localeLang}" is not supported yet by framework`);
+        }
+
+        if (localeLang && lang && localeLang !== lang) {
+            console.info(`Locale Native: Instead of "${localeLang}" language, "${lang}" is used`);
+        }
+
+        this.language = lang;
+    }
+
+    public lang(): Language {
+        if (!this.language) {
             throw new Error("Locale Native: Unable to get UI language");
         }
 
-        return lang;
+        return this.language;
     }
 
     public keys(): Set<keyof LocaleNativeStructure> {
diff --git a/src/locale/utils.ts b/src/locale/utils.ts
index fa6aad9b..8e8bb564 100644
--- a/src/locale/utils.ts
+++ b/src/locale/utils.ts
@@ -1,5 +1,6 @@
 import {
     Language,
+    LanguageCodes,
     LocaleDir,
     LocaleKeyMarker,
     LocaleKeysSeparator,
@@ -55,3 +56,13 @@ export const getLocaleDir = (lang: Language): LocaleDir => {
 export const flattenLocaleMessages = (messages: LocaleMessages): Record<string, string> => {
     return Object.fromEntries(Object.entries(messages).map(([key, value]) => [key, value.message]));
 };
+
+export const normalizeLocale = (language?: string): Language | undefined => {
+    let lang: Language | undefined = language as Language;
+
+    if (lang && !LanguageCodes.has(lang)) {
+        lang = lang.slice(0, 2) as Language;
+    }
+
+    return LanguageCodes.has(lang) ? lang : undefined;
+};