import { HoppModule, HOPP_MODULES } from '.';
import {
  createRouter,
  createWebHistory,
  RouteLocationNormalized,
} from 'vue-router';
import { setupLayouts } from 'virtual:generated-layouts';
import generatedRoutes from 'virtual:generated-pages';
import { readonly, ref } from 'vue';

const routes = setupLayouts(generatedRoutes);

/**
 * A reactive value signifying whether we are currently navigating
 * into the first route the application is routing into.
 * Useful, if you want to do stuff for the initial page load (for example splash screens!)
 */
const _isLoadingInitialRoute = ref(false);

/**
 * Says whether a given route looks like an initial route which
 * is loaded as the first route.
 *
 * NOTE: This function assumes Vue Router represents that initial route
 * in the way we expect (fullPath == "/" and name == undefined). If this
 * function breaks later on, most probs vue-router updated its semantics
 * and we have to correct this function.
 */
function isInitialRoute(route: RouteLocationNormalized) {
  return route.fullPath === '/' && route.name === undefined;
}

/**
 * A reactive value signifying whether we are currently navigating
 * into the first route the application is routing into.
 * Useful, if you want to do stuff for the initial page load (for example splash screens!)
 *
 * NOTE: This reactive value is READONLY
 */
export const isLoadingInitialRoute = readonly(_isLoadingInitialRoute);

export default <HoppModule>{
  onVueAppInit(app) {
    const router = createRouter({
      history: createWebHistory(import.meta.env.BASE_URL),
      routes,
    });

    router.beforeEach((to, from, next) => {
      _isLoadingInitialRoute.value = isInitialRoute(from);

      HOPP_MODULES.forEach((mod) => {
        mod.onBeforeRouteChange?.(to, from, next, router);
      });
    });

    // Instead of this a better architecture is for the router
    // module to expose a stream of router events that can be independently
    // subbed to
    router.afterEach((to) => {
      _isLoadingInitialRoute.value = false;

      HOPP_MODULES.forEach((mod) => {
        mod.onAfterRouteChange?.(to, router);
      });
    });

    app.use(router);

    HOPP_MODULES.forEach((mod) => mod.onRouterInit?.(app, router));
  },
};