import { NextResponse } from "next/server";
import type { NextRequest } from "next/server";
import {
  CYBERLUX_ENTRY_COOKIE,
  parseCyberluxEntry,
  type CyberluxEntry,
} from "@/lib/cyberluxEntry";
import { DEDICATED_ROOT } from "@/lib/onionRoutes.generated";
import { isOnionCrossNavPath } from "@/lib/cyberluxCrossNav";

/** Set by nginx per Tor vhost: `proxy_set_header X-Cyberlux-Node <node>;` */
function entryFromRequest(request: NextRequest): CyberluxEntry {
  return parseCyberluxEntry(request.headers.get("x-cyberlux-node"));
}

function isCrossNavPath(pathname: string): boolean {
  return isOnionCrossNavPath(pathname);
}

function withEntryCookie(res: NextResponse, request: NextRequest): NextResponse {
  const entry = entryFromRequest(request);
  res.cookies.set(CYBERLUX_ENTRY_COOKIE, entry, {
    path: "/",
    sameSite: "lax",
    maxAge: 60 * 60 * 24 * 400,
    httpOnly: false,
  });
  return res;
}

function handleDedicatedRoot(
  request: NextRequest,
  pathname: string,
  root: string,
): NextResponse {
  if (isCrossNavPath(pathname)) {
    return withEntryCookie(NextResponse.next(), request);
  }
  const suffix = pathname === "/" ? "" : pathname;
  return withEntryCookie(
    NextResponse.rewrite(new URL(`${root}${suffix}`, request.url)),
    request,
  );
}

/**
 * Next.js 16+ proxy (replaces `middleware.ts`). Runs on Node; no `export const config` here.
 */
export function proxy(request: NextRequest) {
  const { pathname } = request.nextUrl;
  const entry = entryFromRequest(request);

  if (pathname.startsWith("/_next") || pathname.startsWith("/favicon")) {
    return withEntryCookie(NextResponse.next(), request);
  }
  // Same idea as legacy middleware `matcher`: skip typical static files
  if (/\.[a-zA-Z0-9]{2,5}$/.test(pathname)) {
    return withEntryCookie(NextResponse.next(), request);
  }

  if (entry === "wiki") {
    if (isCrossNavPath(pathname)) {
      return withEntryCookie(NextResponse.next(), request);
    }
    return withEntryCookie(
      NextResponse.rewrite(new URL("/hidden-wiki", request.url)),
      request,
    );
  }

  if (entry === "w") {
    if (isCrossNavPath(pathname)) {
      return withEntryCookie(NextResponse.next(), request);
    }
    if (pathname === "/") {
      return withEntryCookie(
        NextResponse.rewrite(new URL("/syndicate", request.url)),
        request,
      );
    }
    const rest = pathname.startsWith("/") ? pathname.slice(1) : pathname;
    return withEntryCookie(
      NextResponse.rewrite(new URL(`/w/${rest}`, request.url)),
      request,
    );
  }

  if (entry !== "hub" && entry in DEDICATED_ROOT) {
    const root = DEDICATED_ROOT[entry as keyof typeof DEDICATED_ROOT];
    return handleDedicatedRoot(request, pathname, root);
  }

  return withEntryCookie(NextResponse.next(), request);
}