import { useEffect, useRef } from "react";

import * as Notifications from "expo-notifications";

import { useRouter, useRootNavigationState } from "expo-router";

export function useNotificationObserver() {

  const router = useRouter();

  const rootNavState = useRootNavigationState();

  const routerReady = !!rootNavState?.key;

  const handled = useRef(false);

  const lastHandledId = useRef<string | null>(null);

  useEffect(() => {

    if (!routerReady) return;

    if (handled.current) return;

    let isMounted = true;

    function handleResponse(

      response: Notifications.NotificationResponse | null,

      coldLaunch: boolean,

    ) {

      if (!response || !isMounted) return;

      const id = response.notification.request.identifier;

      const { request } = response.notification;

      const { content } = request;

      const { title, body, subtitle, data } = content;

      if (lastHandledId.current === id) return;

      lastHandledId.current = id;

      // XXX: Looks so dumb, actually

      const { screen, ...params } = (data ?? {}) as Record<string, any>;

      if (!screen) return;

      const payload = { body, title, ...params };

      if (coldLaunch) {

        router.replace({

          pathname: screen as any,

          params: payload,

        });

      } else {

        router.push({

          pathname: screen as any,

          params: payload,

        });

      }

    }

    // Cold launch

    Notifications.getLastNotificationResponseAsync().then((response) => {

      if (!handled.current) {

        handled.current = true;

        handleResponse(response, true);

      }

    });

    // Warm/foreground

    const subscription = Notifications.addNotificationResponseReceivedListener(

      (response) => {

        handleResponse(response, false);

      },

    );

    return () => {

      isMounted = false;

      subscription.remove();

    };

  }, [routerReady, router]);

}