App router 404 localization (#57230)

src/app/lib/server-context-utils.ts

@@ -0,0 +1,45 @@
+import { extractLanguageFromPath } from '@/app/lib/language-utils'
+import { extractVersionFromPath } from '@/app/lib/version-utils'
+import { getUIDataMerged } from '@/data-directory/lib/get-data'
+import { type ClientLanguageCode } from '@/languages/lib/client-languages'
+import { createTranslationFunctions, translate } from '@/languages/lib/translation-utils'
+
+export interface ServerAppRouterContext {
+  currentLanguage: ClientLanguageCode
+  currentVersion: string
+  sitename: string
+  site: { data: { ui: any } }
+}
+
+/**
+ * Server-side context creation using filesystem data
+ * Use in server components where filesystem access is available
+ */
+export function createServerAppRouterContext(pathname: string): ServerAppRouterContext {
+  const language = extractLanguageFromPath(pathname)
+  const currentVersion = extractVersionFromPath(pathname)
+
+  const uiData = getUIDataMerged(language)
+  const siteName = translate(uiData, 'header.github_docs', 'GitHub Docs')
+
+  return {
+    currentLanguage: language,
+    currentVersion,
+    sitename: siteName,
+    site: { data: { ui: uiData } },
+  }
+}
+
+/**
+ * Create server-side footer with translations
+ */
+export function createServerFooterContent(language: ClientLanguageCode) {
+  const uiData = getUIDataMerged(language)
+  const { t } = createTranslationFunctions(uiData, 'footer')
+
+  return {
+    t,
+    language,
+    footerData: uiData.footer || {},
+  }
+}