middleware.ts

const HELP_HOST = "seogets.hc.ferndesk.com";
const PROXY_PREFIX = "/help";

export default async function middleware(request: Request): Promise<Response> {
  const originalUrl = new URL(request.url);

  const upstreamUrl = new URL(originalUrl.toString());
  upstreamUrl.hostname = HELP_HOST;

  if (upstreamUrl.pathname === PROXY_PREFIX || upstreamUrl.pathname === `${PROXY_PREFIX}/`) {
    upstreamUrl.pathname = "/";
  } else if (upstreamUrl.pathname.startsWith(`${PROXY_PREFIX}/`)) {
    let upstreamPath = upstreamUrl.pathname.slice(PROXY_PREFIX.length) || "/";
    if (upstreamPath.endsWith("/") && upstreamPath !== "/") {
      upstreamPath = upstreamPath.slice(0, -1);
    }
    upstreamUrl.pathname = upstreamPath;
  }

  const proxyRequest = new Request(upstreamUrl.toString(), request);

  // CRITICAL: Needed to resolve requests correctly
  proxyRequest.headers.set("X-Ferndesk-Base-Path", PROXY_PREFIX);
  proxyRequest.headers.set("X-Forwarded-Host", originalUrl.host);
  proxyRequest.headers.set("X-Ferndesk-Original-Host", originalUrl.host);

  return fetch(proxyRequest);
}

export const config = {
  matcher: ["/help", "/help/", "/help/(.*)", "/_ferndesk/(.*)"],
};