Add dedicated local admin domain routing

lib/admin-routing.ts

@@ -1,6 +1,7 @@
 const DEFAULT_ADMIN_HOST = "root.mohfarawati.de";
 const DEFAULT_ADMIN_URL = `https://${DEFAULT_ADMIN_HOST}`;
 const DEFAULT_SITE_URL = "https://mohfarawati.de";
+const DEV_ADMIN_PREFIX = "/root";
 
 export const INTERNAL_ADMIN_PREFIX = "/admin-internal";
 
@@ -16,10 +17,32 @@ function normalizeBaseUrl(url: string): string {
   return url.replace(/\/+$/, "");
 }
 
+function parseHostname(value: string | undefined): string | undefined {
+  if (!value) {
+    return undefined;
+  }
+
+  const trimmed = value.trim().toLowerCase();
+
+  if (!trimmed) {
+    return undefined;
+  }
+
+  try {
+    return new URL(trimmed).hostname.toLowerCase();
+  } catch {
+    return trimmed.replace(/^https?:\/\//, "").split("/")[0]?.replace(/:\d+$/, "") || undefined;
+  }
+}
+
 export function getAdminHost(): string {
   return (process.env.ADMIN_HOST ?? DEFAULT_ADMIN_HOST).trim().toLowerCase();
 }
 
+export function getSiteHost(): string {
+  return parseHostname(process.env.NEXT_PUBLIC_SITE_URL ?? DEFAULT_SITE_URL) ?? "localhost";
+}
+
 export function getRequestHostname(hostHeader?: string | null): string {
   return (hostHeader ?? "")
     .split(",")[0]
@@ -32,10 +55,18 @@ export function isAdminHost(hostname: string): boolean {
   return hostname === getAdminHost();
 }
 
+export function hasDedicatedAdminHost(): boolean {
+  return getAdminHost() !== getSiteHost();
+}
+
 export function isLegacyAdminPath(pathname: string): boolean {
   return pathname === "/root" || pathname.startsWith("/root/");
 }
 
+export function isDevelopmentAdminPath(pathname: string): boolean {
+  return pathname === DEV_ADMIN_PREFIX || pathname.startsWith(`${DEV_ADMIN_PREFIX}/`);
+}
+
 export function isInternalAdminPath(pathname: string): boolean {
   return pathname === INTERNAL_ADMIN_PREFIX || pathname.startsWith(`${INTERNAL_ADMIN_PREFIX}/`);
 }
@@ -50,12 +81,36 @@ export function toInternalAdminPath(pathname: string): string {
   return `${INTERNAL_ADMIN_PREFIX}${normalizedPathname}`;
 }
 
+export function fromDevelopmentAdminPath(pathname: string): string {
+  if (pathname === DEV_ADMIN_PREFIX) {
+    return "/";
+  }
+
+  if (pathname.startsWith(`${DEV_ADMIN_PREFIX}/`)) {
+    return pathname.slice(DEV_ADMIN_PREFIX.length);
+  }
+
+  return pathname;
+}
+
 export function getAdminBaseUrl(): string {
   return normalizeBaseUrl(process.env.NEXT_PUBLIC_ADMIN_URL ?? DEFAULT_ADMIN_URL);
 }
 
+export function getAdminAppPath(pathname = "/"): string {
+  const normalizedPathname = normalizePathname(pathname);
+
+  if (process.env.NODE_ENV !== "production" && !hasDedicatedAdminHost()) {
+    return normalizedPathname === "/"
+      ? DEV_ADMIN_PREFIX
+      : `${DEV_ADMIN_PREFIX}${normalizedPathname}`;
+  }
+
+  return normalizedPathname;
+}
+
 export function buildAdminUrl(pathname = "/"): string {
-  return `${getAdminBaseUrl()}${normalizePathname(pathname)}`;
+  return `${getAdminBaseUrl()}${getAdminAppPath(pathname)}`;
 }
 
 export function getSiteBaseUrl(): string {