gate locale behind functional consent

dist/modules/i18n/localeMiddleware.js

@@ -1,3 +1,4 @@
+import { CONSENT_COOKIE, parseConsent } from '../consent/storage.js';
 import { isValidLocale, LOCALE_COOKIE_NAME, negotiateLocale } from '../i18n/index.js';
 /**
  * First path segment of a URL pathname, or '' for root.
@@ -14,22 +15,24 @@ import { isValidLocale, LOCALE_COOKIE_NAME, negotiateLocale } from '../i18n/inde
  *    comes from negotiateLocale (cookie → Accept-Language → default)
  *  - the chosen locale is written to a cookie so the next visit is stable
  *
- * The plugin returns a decision; the thin next-middleware.ts in the client project
+ * The plugin returns a decision; the thin middleware.ts in the client project
  * turns it into a NextResponse. This keeps all logic in the plugin while
- * respecting that next-middleware.ts must physically live in the client app.
+ * respecting that middleware.ts must physically live in the client app.
  *
  * @example
- * // next-middleware.ts (client project) — one wiring file, no logic:
+ * // middleware.ts (client project) — one wiring file, no logic:
  * import { NextResponse } from 'next/server'
  * import { localeMiddleware } from './ipal.middleware' // created from this factory
- * export function middleware(req) {
+ * export function proxy(req) {
  *   const r = localeMiddleware(req)
  *   if (r.type === 'next') return NextResponse.next()
  *   const res = NextResponse.redirect(r.location)
- *   res.cookies.set(r.cookie.name, r.cookie.value)
+ *   // cookie is optional: only present when the visitor consented to the
+ *   // gating category (functional by default). Guard before setting.
+ *   if (r.cookie) res.cookies.set(r.cookie.name, r.cookie.value)
  *   return res
  * }
- */ export function createLocaleMiddleware({ config, cookieName = LOCALE_COOKIE_NAME }) {
+ */ export function createLocaleMiddleware({ config, consentCategory = 'functional', consentCookieName = CONSENT_COOKIE, cookieName = LOCALE_COOKIE_NAME }) {
     return function localeMiddleware(request) {
         const { pathname } = request.nextUrl;
         // Already locale-prefixed → nothing to do
@@ -47,13 +50,27 @@ import { isValidLocale, LOCALE_COOKIE_NAME, negotiateLocale } from '../i18n/inde
         // Redirect to the locale-prefixed path, preserving the rest
         const url = request.nextUrl.clone();
         url.pathname = `/${locale}${pathname === '/' ? '' : pathname}`;
+        // Persist the locale choice ONLY if the visitor consented to the gating
+        // category. 'necessary' is always granted, so passing consentCategory:
+        // 'necessary' always persists. For 'functional' (default), we read the
+        // consent cookie and only write the locale cookie when functional is true.
+        // Without consent the locale is still detected each request (routing works),
+        // it just isn't remembered across visits — which is the whole point of
+        // gating a functional cookie behind consent.
+        let mayPersist = consentCategory === 'necessary';
+        if (!mayPersist) {
+            const consent = parseConsent(request.cookies.get(consentCookieName)?.value);
+            mayPersist = consent?.[consentCategory] === true;
+        }
         return {
             type: 'redirect',
-            cookie: {
-                name: cookieName,
-                value: locale
-            },
-            location: url.toString()
+            location: url.toString(),
+            ...mayPersist ? {
+                cookie: {
+                    name: cookieName,
+                    value: locale
+                }
+            } : {}
         };
     };
 }