import type { IncomingMessage, ServerResponse } from "node:http";
import type { ClientRequest, IncomingMessage as ProxyIncomingMessage } from "node:http";
import type { ProxyOptions } from "vite";
import { MENU_SITE_ORIGIN, isMenuSlugProxyPath, stripMenuPreviewCacheParam, toMenuSitePath } from "./src/config/menuPreview";

const stripFrameHeaders = (_proxyRes: ProxyIncomingMessage, _req: IncomingMessage, res: ServerResponse) => {
  res.removeHeader("x-frame-options");
  res.removeHeader("content-security-policy");
};

const stripPreviewPageHeaders = (_proxyRes: ProxyIncomingMessage, _req: IncomingMessage, res: ServerResponse) => {
  stripFrameHeaders(_proxyRes, _req, res);
  res.removeHeader("cache-control");
  res.removeHeader("etag");
  res.removeHeader("last-modified");
  res.setHeader("cache-control", "no-store, no-cache, must-revalidate");
  res.setHeader("pragma", "no-cache");
  res.setHeader("expires", "0");
};

const menuAssetProxy = (): ProxyOptions => ({
  target: MENU_SITE_ORIGIN,
  changeOrigin: true,
  secure: true,
  configure: (proxy) => {
    proxy.on("proxyRes", stripFrameHeaders);
  },
});

export const createMenuPreviewProxy = (): Record<string, ProxyOptions> => ({
  "/assets/fonts": menuAssetProxy(),
  "/assets/images": menuAssetProxy(),
  "/_next": menuAssetProxy(),
  "/icons": menuAssetProxy(),
});

export const shouldProxyMenuSlugRequest = (url: string | undefined) => {
  if (!url) return false;

  const pathname = url.split("?")[0] ?? "";
  if (pathname.startsWith("/@") || pathname.startsWith("/src/") || pathname.startsWith("/node_modules/")) {
    return false;
  }

  if (
    pathname.startsWith("/assets/fonts/") ||
    pathname.startsWith("/assets/images/") ||
    pathname.startsWith("/_next/") ||
    pathname.startsWith("/icons/")
  ) {
    return false;
  }

  if (pathname.startsWith("/assets/")) {
    return false;
  }

  return isMenuSlugProxyPath(pathname);
};

export const getMenuSiteTargetUrl = (url: string) => {
  const [pathname, search = ""] = url.split("?");
  const menuPath = toMenuSitePath(pathname ?? "");
  if (!menuPath) return null;
  return `${MENU_SITE_ORIGIN}${menuPath}${stripMenuPreviewCacheParam(search)}`;
};

export const createMenuSlugProxyAgent = () => ({
  configure: (proxy: { on: (event: string, handler: (...args: unknown[]) => void) => void }) => {
    proxy.on("proxyReq", (proxyReq: ClientRequest) => {
      proxyReq.removeHeader("origin");
    });
    proxy.on("proxyRes", stripPreviewPageHeaders);
  },
});