import { useEffect, type ReactNode } from "react";

export type UhuruRouteGuardProps = {
  children?: ReactNode;
  fallback?: ReactNode;
  allow?: boolean;
  check?: () => boolean;
  onDenied?: () => void;
  redirectTo?: string;
};

/** Protects one route, a route group, or an entire Uhuru app shell. */
export function UhuruRouteGuard({
  allow,
  check,
  children,
  fallback = null,
  onDenied,
  redirectTo,
}: UhuruRouteGuardProps) {
  const permitted = allow ?? check?.() ?? true;

  useEffect(() => {
    if (permitted) {
      return;
    }

    onDenied?.();

    if (redirectTo && typeof window !== "undefined" && window.location.pathname !== redirectTo) {
      window.history.replaceState({}, "", redirectTo);
      window.dispatchEvent(new PopStateEvent("popstate"));
    }
  }, [onDenied, permitted, redirectTo]);

  return permitted ? children : fallback;
}