fix: persist user locale preference to database (#1547)

src/services/locale.ts

@@ -2,10 +2,13 @@
 
 import { cookies, headers } from "next/headers";
 import { Locale, defaultLocale, locales } from "@/i18n/config";
+import { internal } from "@app/lib/api";
+import { authCookieHeader } from "@app/lib/api/cookies";
 
 // In this example the locale is read from a cookie. You could alternatively
 // also read it from a database, backend service, or any other source.
 const COOKIE_NAME = "NEXT_LOCALE";
+const COOKIE_MAX_AGE = 365 * 24 * 60 * 60; // 1 year in seconds
 
 export async function getUserLocale(): Promise<Locale> {
     const cookieLocale = (await cookies()).get(COOKIE_NAME)?.value;
@@ -14,6 +17,23 @@ export async function getUserLocale(): Promise<Locale> {
         return cookieLocale as Locale;
     }
 
+    // No cookie found — try to restore from user's saved locale in DB
+    try {
+        const res = await internal.get("/user", await authCookieHeader());
+        const userLocale = res.data?.data?.locale;
+        if (userLocale && locales.includes(userLocale as Locale)) {
+            // Set the cookie so subsequent requests don't need the API call
+            (await cookies()).set(COOKIE_NAME, userLocale, {
+                maxAge: COOKIE_MAX_AGE,
+                path: "/",
+                sameSite: "lax"
+            });
+            return userLocale as Locale;
+        }
+    } catch {
+        // User not logged in or API unavailable — fall through
+    }
+
     const headerList = await headers();
     const acceptLang = headerList.get("accept-language");
 
@@ -33,5 +53,9 @@ export async function getUserLocale(): Promise<Locale> {
 }
 
 export async function setUserLocale(locale: Locale) {
-    (await cookies()).set(COOKIE_NAME, locale);
+    (await cookies()).set(COOKIE_NAME, locale, {
+        maxAge: COOKIE_MAX_AGE,
+        path: "/",
+        sameSite: "lax"
+    });
 }