import type { Page } from "../../lib/urlState";
import type { NavigationState } from "./navigationContext";

/** The page whose own keys the address bar carries: none while the channel page stands over it, so
 *  every module store writes its keys (`useUrlMirror`) only while its page is what the screen shows.
 *  A plain function beside the context, not a hook in it: the stores' tests mock that module. */
export function urlPage(nav: Pick<NavigationState, "page" | "channelView">): Page | null {
  return nav.channelView ? null : nav.page;
}