Initial commit

web/middleware.ts

@@ -0,0 +1,39 @@
+import { match } from '@formatjs/intl-localematcher'
+import Negotiator from 'negotiator'
+import { NextResponse } from 'next/server'
+import type { NextRequest } from 'next/server'
+import type { Locale } from './i18n'
+import { i18n } from './i18n'
+
+export const getLocale = (request: NextRequest): Locale => {
+  // @ts-expect-error locales are readonly
+  const locales: Locale[] = i18n.locales
+
+  let languages: string[] | undefined
+  // get locale from cookie
+  const localeCookie = request.cookies.get('locale')
+  languages = localeCookie?.value ? [localeCookie.value] : []
+
+  if (!languages.length) {
+    // Negotiator expects plain object so we need to transform headers
+    const negotiatorHeaders: Record<string, string> = {}
+    request.headers.forEach((value, key) => (negotiatorHeaders[key] = value))
+    // Use negotiator and intl-localematcher to get best locale
+    languages = new Negotiator({ headers: negotiatorHeaders }).languages()
+  }
+
+  // match locale
+  const matchedLocale = match(languages, locales, i18n.defaultLocale) as Locale
+  return matchedLocale
+}
+
+export const middleware = async (request: NextRequest) => {
+  const pathname = request.nextUrl.pathname
+  if (/\.(css|js(on)?|ico|svg|png)$/.test(pathname))
+    return
+
+  const locale = getLocale(request)
+  const response = NextResponse.next()
+  response.cookies.set('locale', locale)
+  return response
+}