From 164c2bdaa61d2df597c810fcf2b57768aee4ecad Mon Sep 17 00:00:00 2001
From: andreyjan <chemberdjian@gmail.com>
Date: Thu, 29 Aug 2024 15:32:54 +0300
Subject: [PATCH] Make language switcher work with translatable slugs.

---
 app/[locale]/[[...slug]]/page.tsx             | 18 +++++++----
 app/[locale]/layout.tsx                       | 11 ++++---
 app/[locale]/locale-provider.tsx              |  4 +--
 components/language-data-provider/index.ts    |  1 +
 .../language-data-provider.tsx                | 14 ++++++++
 .../language-data-setter.tsx                  | 15 +++++++++
 .../language-selector/language-selector.tsx   | 32 ++++++++++++++-----
 ui/context/index.ts                           |  1 +
 ui/context/language-data.context.ts           |  4 +++
 ui/hooks/index.ts                             |  1 +
 ui/hooks/use-language-data-context.hook.ts    |  8 +++++
 11 files changed, 89 insertions(+), 20 deletions(-)
 create mode 100644 components/language-data-provider/index.ts
 create mode 100644 components/language-data-provider/language-data-provider.tsx
 create mode 100644 components/language-data-provider/language-data-setter.tsx
 create mode 100644 ui/context/index.ts
 create mode 100644 ui/context/language-data.context.ts
 create mode 100644 ui/hooks/index.ts
 create mode 100644 ui/hooks/use-language-data-context.hook.ts

diff --git a/app/[locale]/[[...slug]]/page.tsx b/app/[locale]/[[...slug]]/page.tsx
index da29492..a270472 100644
--- a/app/[locale]/[[...slug]]/page.tsx
+++ b/app/[locale]/[[...slug]]/page.tsx
@@ -7,6 +7,7 @@ import { ComponentRenderer } from '#/components/component-renderer';
 import DebugMode from '#/components/debug-mode/debug-mode';
 import { ComponentDuplexFieldsFragment } from '#/components/duplex-ctf/duplex-ctf';
 import { ComponentHeroBannerFieldsFragment } from '#/components/hero-banner-ctf/hero-banner-ctf';
+import { LanguageDataSetter } from '#/components/language-data-provider/language-data-setter';
 import { graphqlClient } from '#/lib/graphqlClient';
 import { getLocaleFromPath } from '#/locales/get-locale-from-path';
 import { getStaticParams } from '#/locales/server';
@@ -23,6 +24,8 @@ const getPage = async (slug: string, locale: string, preview = false) => {
                 ...ComponentDuplexFields
               }
             }
+            slugEn: slug(locale: "en-US")
+            slugDe: slug(locale: "de-DE")
           }
         }
       }
@@ -38,7 +41,7 @@ const getPage = async (slug: string, locale: string, preview = false) => {
   ).data?.pageCollection?.items?.[0];
 };
 
-const getPageSlugs = async () => {
+const getPageSlugs = async (locale: string) => {
   const pageQuery = graphql(`
     query PageSlugs($locale: String) {
       # Fetch 50 pages. Ideally we would fetch a good sample of most popular pages for pre-rendering,
@@ -52,7 +55,7 @@ const getPageSlugs = async () => {
   `);
 
   const pages = await graphqlClient(false).query(pageQuery, {
-    locale: 'en-US',
+    locale: locale,
   });
 
   return (
@@ -78,6 +81,9 @@ export default async function LandingPage({ params }: { params: { slug: string[]
   return (
     <div>
       <DebugMode slug={slug} />
+      <LanguageDataSetter
+        data={{ ...(pageData?.slugEn && { en: pageData.slugEn }), ...(pageData?.slugDe && { de: pageData.slugDe }) }}
+      />
       {topComponents ? <ComponentRenderer data={topComponents} /> : null}
     </div>
   );
@@ -88,10 +94,10 @@ export const revalidate = 120;
 export async function generateStaticParams() {
   const params = getStaticParams();
   const returnData: Array<{ slug?: string[]; locale: string }> = [];
-  const slugs = (await getPageSlugs()).map((page) => ({
-    slug: page?.slug?.split('/'),
-  }));
-  for (const locale of params) {
+  for await (const locale of params) {
+    const slugs = (await getPageSlugs(getLocaleFromPath(locale.locale))).map((page) => ({
+      slug: page?.slug?.split('/'),
+    }));
     for (const slug of slugs) {
       returnData.push({ slug: slug.slug, locale: locale.locale });
     }
diff --git a/app/[locale]/layout.tsx b/app/[locale]/layout.tsx
index df52c62..8b045d7 100644
--- a/app/[locale]/layout.tsx
+++ b/app/[locale]/layout.tsx
@@ -10,6 +10,7 @@ import '@contentful/live-preview/style.css';
 
 import { LocaleProvider } from '#/app/[locale]/locale-provider';
 import { ContentfulPreviewProvider } from '#/components/contentful-preview-provider';
+import { LanguageDataProvider } from '#/components/language-data-provider';
 import { NavigationFieldsFragment } from '#/components/navigation';
 import { SiteHeader } from '#/components/site-header';
 import { fontSans } from '#/lib/fonts';
@@ -56,10 +57,12 @@ export default async function RootLayout({
       <body className={cn('min-h-screen bg-background font-sans antialiased', fontSans.variable)}>
         <ContentfulPreviewProvider isDraftMode={isDraftMode}>
           <LocaleProvider locale={locale}>
-            <div className="relative flex min-h-screen flex-col">
-              <SiteHeader navigationData={layoutData.data?.navigationMenuCollection} />
-              <div className="flex-1">{children}</div>
-            </div>
+            <LanguageDataProvider>
+              <div className="relative flex min-h-screen flex-col">
+                <SiteHeader navigationData={layoutData.data?.navigationMenuCollection} />
+                <div className="flex-1">{children}</div>
+              </div>
+            </LanguageDataProvider>
           </LocaleProvider>
         </ContentfulPreviewProvider>
       </body>
diff --git a/app/[locale]/locale-provider.tsx b/app/[locale]/locale-provider.tsx
index f885cfa..9cd5172 100644
--- a/app/[locale]/locale-provider.tsx
+++ b/app/[locale]/locale-provider.tsx
@@ -9,10 +9,10 @@ type LocaleProviderProps = {
   children: ReactNode;
 };
 
-export function LocaleProvider({ locale, children }: LocaleProviderProps) {
+export const LocaleProvider = ({ locale, children }: LocaleProviderProps) => {
   return (
     <I18nProviderClient locale={locale} fallback={<p>Loading...</p>}>
       {children}
     </I18nProviderClient>
   );
-}
+};
diff --git a/components/language-data-provider/index.ts b/components/language-data-provider/index.ts
new file mode 100644
index 0000000..6112576
--- /dev/null
+++ b/components/language-data-provider/index.ts
@@ -0,0 +1 @@
+export * from './language-data-provider';
diff --git a/components/language-data-provider/language-data-provider.tsx b/components/language-data-provider/language-data-provider.tsx
new file mode 100644
index 0000000..a67fa96
--- /dev/null
+++ b/components/language-data-provider/language-data-provider.tsx
@@ -0,0 +1,14 @@
+'use client';
+
+import { ReactNode, useState } from 'react';
+
+import { LanguageDataContext } from 'ui/context';
+
+interface LanguageDataProviderProps {
+  children: ReactNode;
+}
+
+export const LanguageDataProvider = ({ children }: LanguageDataProviderProps) => {
+  const slugsState = useState<Record<string, string>>({});
+  return <LanguageDataContext.Provider value={{ slugsState }}>{children}</LanguageDataContext.Provider>;
+};
diff --git a/components/language-data-provider/language-data-setter.tsx b/components/language-data-provider/language-data-setter.tsx
new file mode 100644
index 0000000..4c9149c
--- /dev/null
+++ b/components/language-data-provider/language-data-setter.tsx
@@ -0,0 +1,15 @@
+'use client';
+
+import { useEffect } from 'react';
+
+import { useLanguageDataContext } from '#/ui/hooks';
+
+export const LanguageDataSetter = ({ data }: { data?: Record<string, string> }) => {
+  const [, setSlugs] = useLanguageDataContext()!.slugsState;
+  useEffect(() => {
+    if (data) {
+      setSlugs(data);
+    }
+  }, [data]);
+  return null;
+};
diff --git a/components/language-selector/language-selector.tsx b/components/language-selector/language-selector.tsx
index de1d896..1310c28 100644
--- a/components/language-selector/language-selector.tsx
+++ b/components/language-selector/language-selector.tsx
@@ -1,19 +1,35 @@
 'use client';
 
-import { useChangeLocale, useCurrentLocale } from '#/locales/client';
+import { ChangeEvent, useTransition } from 'react';
+import { useRouter } from 'next/navigation';
+
+import { useCurrentLocale } from '#/locales/client';
+import { useLanguageDataContext } from '#/ui/hooks';
 
 export const LanguageSelector = () => {
   const locale = useCurrentLocale();
-  const changeLocale = useChangeLocale({ preserveSearchParams: true });
+  const router = useRouter();
+  const [isPending, startTransition] = useTransition();
+  const languageData = useLanguageDataContext();
 
-  const handleLanguageChange = (e: React.ChangeEvent<HTMLSelectElement>) => {
-    changeLocale(e.target.value as 'en' | 'de');
+  const handleLanguageChange = (e: ChangeEvent<HTMLSelectElement>) => {
+    startTransition(() => {
+      const selectedLocale = e.target.value;
+      const [slugs] = languageData?.slugsState ?? [];
+      if (slugs?.[selectedLocale]) {
+        router.push(`/${selectedLocale}/${slugs[selectedLocale]}`);
+      } else {
+        router.push(`/${selectedLocale}`);
+      }
+    });
   };
 
   return (
-    <select value={locale} onChange={handleLanguageChange}>
-      <option value="en">English</option>
-      <option value="de">Deutsche</option>
-    </select>
+    <>
+      <select value={locale} onChange={handleLanguageChange} disabled={isPending}>
+        <option value="en">English</option>
+        <option value="de">Deutsche</option>
+      </select>
+    </>
   );
 };
diff --git a/ui/context/index.ts b/ui/context/index.ts
new file mode 100644
index 0000000..13a1514
--- /dev/null
+++ b/ui/context/index.ts
@@ -0,0 +1 @@
+export * from './language-data.context';
diff --git a/ui/context/language-data.context.ts b/ui/context/language-data.context.ts
new file mode 100644
index 0000000..67692b2
--- /dev/null
+++ b/ui/context/language-data.context.ts
@@ -0,0 +1,4 @@
+import { createContext, Dispatch, SetStateAction } from 'react';
+
+type LanguageData = { slugsState: [Record<string, string>, Dispatch<SetStateAction<Record<string, string>>>] };
+export const LanguageDataContext = createContext<LanguageData | undefined>(undefined);
diff --git a/ui/hooks/index.ts b/ui/hooks/index.ts
new file mode 100644
index 0000000..a35ce30
--- /dev/null
+++ b/ui/hooks/index.ts
@@ -0,0 +1 @@
+export * from './use-language-data-context.hook';
diff --git a/ui/hooks/use-language-data-context.hook.ts b/ui/hooks/use-language-data-context.hook.ts
new file mode 100644
index 0000000..62dd272
--- /dev/null
+++ b/ui/hooks/use-language-data-context.hook.ts
@@ -0,0 +1,8 @@
+import { useContext } from 'react';
+
+import { LanguageDataContext } from '#/ui/context';
+
+export function useLanguageDataContext() {
+  const context = useContext(LanguageDataContext);
+  return context ?? null;
+}