fix: lang switch

app/[locale]/blog/[slug]/page.tsx

@@ -1,4 +1,4 @@
-import { notFound } from 'next/navigation';
+import { notFound, redirect } from 'next/navigation';
 import JsonLd from '@/components/JsonLd';
 import { SITE_URL } from '@/lib/schema';
 import { getPostBySlug, getAdjacentPosts, getReadingTime } from '@/lib/blog';
@@ -32,7 +32,7 @@ export async function generateMetadata({ params }: BlogPostProps): Promise<Metad
     title: post.frontmatter.title,
     description: description,
     alternates: {
-      canonical: `${SITE_URL}/${locale}/blog/${slug}`,
+      canonical: `${SITE_URL}/${locale}/blog/${post.slug}`,
     },
     openGraph: {
       title: `${post.frontmatter.title} | KLZ Cables`,
@@ -40,7 +40,7 @@ export async function generateMetadata({ params }: BlogPostProps): Promise<Metad
       type: 'article',
       publishedTime: post.frontmatter.date,
       authors: ['KLZ Cables'],
-      url: `${SITE_URL}/${locale}/blog/${slug}`,
+      url: `${SITE_URL}/${locale}/blog/${post.slug}`,
     },
     twitter: {
       card: 'summary_large_image',
@@ -54,12 +54,19 @@ export default async function BlogPost({ params }: BlogPostProps) {
   const { locale, slug } = await params;
   setRequestLocale(locale);
   const post = await getPostBySlug(slug, locale);
-  const { prev, next, isPrevRandom, isNextRandom } = await getAdjacentPosts(slug, locale);
 
   if (!post) {
     notFound();
   }
 
+  // If the user accessed this post using a slug from a different locale
+  // (e.g. via the generic language switcher), redirect them to the correct localized slug URL
+  if (post.slug && post.slug !== slug) {
+    redirect(`/${locale}/blog/${post.slug}`);
+  }
+
+  const { prev, next, isPrevRandom, isNextRandom } = await getAdjacentPosts(post.slug, locale);
+
   // Convert Lexical content into a plain string to estimate reading time roughly
   const rawTextContent = JSON.stringify(post.content);