calendar/apps/web/middleware.ts

import { collectEvents } from "next-collect/server";
import { NextMiddleware, NextResponse, userAgent } from "next/server";

import { CONSOLE_URL, WEBAPP_URL, WEBSITE_URL } from "@calcom/lib/constants";
import { isIpInBanlist } from "@calcom/lib/getIP";
import { extendEventData, nextCollectBasicSettings } from "@calcom/lib/telemetry";

const V2_WHITELIST = [
  "/settings/admin",
  "/settings/my-account",
  "/availability",
  "/bookings",
  "/event-types",
];

const middleware: NextMiddleware = async (req) => {
  const url = req.nextUrl;

  if (["/api/collect-events", "/api/auth"].some((p) => url.pathname.startsWith(p))) {
    const callbackUrl = url.searchParams.get("callbackUrl");
    const { isBot } = userAgent(req);

    if (
      isBot ||
      (callbackUrl && ![CONSOLE_URL, WEBAPP_URL, WEBSITE_URL].some((u) => callbackUrl.startsWith(u))) ||
      isIpInBanlist(req)
    ) {
      // DDOS Prevention: Immediately end request with no response - Avoids a redirect as well initiated by NextAuth on invalid callback
      req.nextUrl.pathname = "/api/nope";
      return NextResponse.redirect(req.nextUrl);
    }
  }
  /** Display available V2 pages to users who opted-in to early access */
  if (req.cookies.has("calcom-v2-early-access") && V2_WHITELIST.some((p) => url.pathname.startsWith(p))) {
    // rewrite to the current subdomain under the pages/sites folder
    url.pathname = `/v2${url.pathname}`;
  }

  return NextResponse.rewrite(url);
};

export default collectEvents({
  middleware,
  ...nextCollectBasicSettings,
  cookieName: "__clnds",
  extend: extendEventData,
});