feat(i18n): add localized navigation and news translations

apps/admin/src/app/news/page.tsx

@@ -1,4 +1,10 @@
-import { createPost, deletePost, listPosts, updatePost } from "@cms/db"
+import {
+  createPost,
+  deletePost,
+  listPostsWithTranslations,
+  updatePost,
+  upsertPostTranslation,
+} from "@cms/db"
 import { Button } from "@cms/ui/button"
 import { revalidatePath } from "next/cache"
 import { redirect } from "next/navigation"
@@ -9,6 +15,9 @@ import { requirePermissionForRoute } from "@/lib/route-guards"
 export const dynamic = "force-dynamic"
 
 type SearchParamsInput = Record<string, string | string[] | undefined>
+const SUPPORTED_LOCALES = ["de", "en", "es", "fr"] as const
+
+type SupportedLocale = (typeof SUPPORTED_LOCALES)[number]
 
 function readFirstValue(value: string | string[] | undefined): string | null {
   if (Array.isArray(value)) {
@@ -28,6 +37,14 @@ function readNullableString(formData: FormData, field: string): string | undefin
   return value.length > 0 ? value : undefined
 }
 
+function normalizeLocale(input: string | null): SupportedLocale {
+  if (input && SUPPORTED_LOCALES.includes(input as SupportedLocale)) {
+    return input as SupportedLocale
+  }
+
+  return "en"
+}
+
 function redirectWithState(params: { notice?: string; error?: string }) {
   const query = new URLSearchParams()
 
@@ -115,6 +132,34 @@ async function deleteNewsAction(formData: FormData) {
   redirectWithState({ notice: "Post deleted." })
 }
 
+async function upsertNewsTranslationAction(formData: FormData) {
+  "use server"
+
+  await requirePermissionForRoute({
+    nextPath: "/news",
+    permission: "news:write",
+    scope: "team",
+  })
+
+  const locale = normalizeLocale(readInputString(formData, "locale"))
+
+  try {
+    await upsertPostTranslation({
+      postId: readInputString(formData, "postId"),
+      locale,
+      title: readInputString(formData, "title"),
+      excerpt: readNullableString(formData, "excerpt") ?? null,
+      body: readInputString(formData, "body"),
+    })
+  } catch {
+    redirectWithState({ error: "Failed to save translation." })
+  }
+
+  revalidatePath("/news")
+  revalidatePath("/")
+  redirectWithState({ notice: "Post translation saved." })
+}
+
 export default async function NewsManagementPage({
   searchParams,
 }: {
@@ -126,10 +171,14 @@ export default async function NewsManagementPage({
     scope: "team",
   })
 
-  const [resolvedSearchParams, posts] = await Promise.all([searchParams, listPosts()])
+  const [resolvedSearchParams, posts] = await Promise.all([
+    searchParams,
+    listPostsWithTranslations(),
+  ])
 
   const notice = readFirstValue(resolvedSearchParams.notice)
   const error = readFirstValue(resolvedSearchParams.error)
+  const selectedLocale = normalizeLocale(readFirstValue(resolvedSearchParams.locale))
 
   return (
     <AdminShell
@@ -204,72 +253,146 @@ export default async function NewsManagementPage({
       </section>
 
       <section className="space-y-3">
-        {posts.map((post) => (
-          <form
-            key={post.id}
-            action={updateNewsAction}
-            className="rounded-xl border border-neutral-200 p-6"
-          >
-            <input type="hidden" name="id" value={post.id} />
-            <div className="grid gap-3 md:grid-cols-2">
-              <label className="space-y-1">
-                <span className="text-xs text-neutral-600">Title</span>
-                <input
-                  name="title"
-                  defaultValue={post.title}
-                  className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
-                />
-              </label>
-              <label className="space-y-1">
-                <span className="text-xs text-neutral-600">Slug</span>
-                <input
-                  name="slug"
-                  defaultValue={post.slug}
-                  className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
-                />
-              </label>
-            </div>
-            <label className="mt-3 block space-y-1">
-              <span className="text-xs text-neutral-600">Excerpt</span>
-              <input
-                name="excerpt"
-                defaultValue={post.excerpt ?? ""}
-                className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
-              />
-            </label>
-            <label className="mt-3 block space-y-1">
-              <span className="text-xs text-neutral-600">Body</span>
-              <textarea
-                name="body"
-                rows={4}
-                defaultValue={post.body}
-                className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
-              />
-            </label>
-            <div className="mt-3 flex flex-wrap items-center justify-between gap-3">
-              <select
-                name="status"
-                defaultValue={post.status}
-                className="rounded border border-neutral-300 px-3 py-2 text-sm"
+        <div className="flex flex-wrap gap-2">
+          {SUPPORTED_LOCALES.map((locale) => (
+            <a
+              key={locale}
+              href={`/news?locale=${locale}`}
+              className={`inline-flex rounded border px-3 py-1.5 text-xs ${
+                selectedLocale === locale
+                  ? "border-neutral-800 bg-neutral-900 text-white"
+                  : "border-neutral-300 text-neutral-700"
+              }`}
+            >
+              {locale.toUpperCase()}
+            </a>
+          ))}
+        </div>
+
+        {posts.map((post) => {
+          const translation = post.translations.find((entry) => entry.locale === selectedLocale)
+
+          return (
+            <div key={post.id} className="rounded-xl border border-neutral-200 p-6">
+              <form action={updateNewsAction}>
+                <input type="hidden" name="id" value={post.id} />
+                <div className="grid gap-3 md:grid-cols-2">
+                  <label className="space-y-1">
+                    <span className="text-xs text-neutral-600">Title</span>
+                    <input
+                      name="title"
+                      defaultValue={post.title}
+                      className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
+                    />
+                  </label>
+                  <label className="space-y-1">
+                    <span className="text-xs text-neutral-600">Slug</span>
+                    <input
+                      name="slug"
+                      defaultValue={post.slug}
+                      className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
+                    />
+                  </label>
+                </div>
+                <label className="mt-3 block space-y-1">
+                  <span className="text-xs text-neutral-600">Excerpt</span>
+                  <input
+                    name="excerpt"
+                    defaultValue={post.excerpt ?? ""}
+                    className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
+                  />
+                </label>
+                <label className="mt-3 block space-y-1">
+                  <span className="text-xs text-neutral-600">Body</span>
+                  <textarea
+                    name="body"
+                    rows={4}
+                    defaultValue={post.body}
+                    className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
+                  />
+                </label>
+                <div className="mt-3 flex flex-wrap items-center justify-between gap-3">
+                  <select
+                    name="status"
+                    defaultValue={post.status}
+                    className="rounded border border-neutral-300 px-3 py-2 text-sm"
+                  >
+                    <option value="draft">draft</option>
+                    <option value="published">published</option>
+                  </select>
+                  <div className="flex items-center gap-2">
+                    <Button type="submit" size="sm">
+                      Save
+                    </Button>
+                    <button
+                      type="submit"
+                      formAction={deleteNewsAction}
+                      className="rounded-md border border-red-300 px-3 py-2 text-sm text-red-700"
+                    >
+                      Delete
+                    </button>
+                  </div>
+                </div>
+              </form>
+
+              <form
+                action={upsertNewsTranslationAction}
+                className="mt-4 rounded-lg border border-neutral-200 p-4"
               >
-                <option value="draft">draft</option>
-                <option value="published">published</option>
-              </select>
-              <div className="flex items-center gap-2">
-                <Button type="submit" size="sm">
-                  Save
-                </Button>
-                <button
-                  type="submit"
-                  formAction={deleteNewsAction}
-                  className="rounded-md border border-red-300 px-3 py-2 text-sm text-red-700"
-                >
-                  Delete
-                </button>
-              </div>
+                <input type="hidden" name="postId" value={post.id} />
+                <input type="hidden" name="locale" value={selectedLocale} />
+
+                <h3 className="text-sm font-medium">
+                  Translation ({selectedLocale.toUpperCase()})
+                </h3>
+                <p className="mt-1 text-xs text-neutral-600">
+                  Missing fields fall back to base post content on public pages.
+                </p>
+                {post.translations.length > 0 ? (
+                  <p className="mt-2 text-xs text-neutral-600">
+                    Saved locales:{" "}
+                    {post.translations.map((entry) => entry.locale.toUpperCase()).join(", ")}
+                  </p>
+                ) : null}
+
+                <div className="mt-3 grid gap-3 md:grid-cols-2">
+                  <label className="space-y-1">
+                    <span className="text-xs text-neutral-600">Title</span>
+                    <input
+                      name="title"
+                      defaultValue={translation?.title ?? post.title}
+                      className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
+                    />
+                  </label>
+                  <label className="space-y-1">
+                    <span className="text-xs text-neutral-600">Excerpt</span>
+                    <input
+                      name="excerpt"
+                      defaultValue={translation?.excerpt ?? post.excerpt ?? ""}
+                      className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
+                    />
+                  </label>
+                </div>
+
+                <label className="mt-3 block space-y-1">
+                  <span className="text-xs text-neutral-600">Body</span>
+                  <textarea
+                    name="body"
+                    rows={4}
+                    defaultValue={translation?.body ?? post.body}
+                    className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
+                  />
+                </label>
+
+                <div className="mt-3">
+                  <Button type="submit" size="sm">
+                    Save translation
+                  </Button>
+                </div>
+              </form>
             </div>
-          </form>
-        ))}
+          )
+        })}
       </section>
     </AdminShell>
   )