Fix regional locale detection

2026-09-02 01:09:03 +02:00 · 2026-07-30 14:29:25 +05:30
parent 146c287aba
commit cb3f0b49a8
3 changed files with 124 additions and 6 deletions
@@ -0,0 +1,48 @@
+import { Locale, locales } from "./config";
+
+export function detectLocale(acceptLanguage: string): Locale | undefined {
+    const browserLocales = acceptLanguage
+        .split(",")
+        .map((entry, index) => {
+            const [locale, ...parameters] = entry.trim().split(";");
+            const qualityParameter = parameters.find((parameter) =>
+                parameter.trim().toLowerCase().startsWith("q=")
+            );
+            const quality = qualityParameter
+                ? Number(qualityParameter.trim().slice(2))
+                : 1;
+
+            return {
+                locale: locale.trim().toLowerCase(),
+                quality,
+                index
+            };
+        })
+        .filter(
+            ({ locale, quality }) =>
+                locale && locale !== "*" && quality > 0 && quality <= 1
+        )
+        .sort(
+            (left, right) =>
+                right.quality - left.quality || left.index - right.index
+        );
+
+    for (const { locale: browserLocale } of browserLocales) {
+        const exactMatch = locales.find(
+            (locale) => locale.toLowerCase() === browserLocale
+        );
+        if (exactMatch) {
+            return exactMatch;
+        }
+
+        const browserLanguage = browserLocale.split("-")[0];
+        const languageMatch = locales.find(
+            (locale) => locale.split("-")[0].toLowerCase() === browserLanguage
+        );
+        if (languageMatch) {
+            return languageMatch;
+        }
+    }
+
+    return undefined;
+}