import { lazy } from "react";
import type { ComponentType } from "react";

const RELOAD_KEY = "spa-chunk-reloaded";

/**
 * React.lazy that survives a deploy. If a page's dynamic import fails because
 * its hashed chunk was removed by a newer build, reload once to fetch the fresh
 * bundle (guarded by sessionStorage so a genuine load failure can't loop). On a
 * successful load the guard is cleared so the next deploy can recover too.
 *
 * The generic mirrors React.lazy's own `ComponentType<any>` constraint — there
 * is no non-any equivalent that satisfies it, so the `any` is unavoidable here.
 */
export function lazyWithReload<
  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  T extends ComponentType<any>,
>(factory: () => Promise<{ default: T }>) {
  return lazy(() =>
    factory()
      .then((mod) => {
        sessionStorage.removeItem(RELOAD_KEY);
        return mod;
      })
      .catch((err: unknown) => {
        if (!sessionStorage.getItem(RELOAD_KEY)) {
          sessionStorage.setItem(RELOAD_KEY, "1");
          window.location.reload();
          // Never resolves — the reload replaces the document.
          return new Promise<{ default: T }>(() => {});
        }
        throw err;
      }),
  );
}