import { useEffect, useRef } from 'react';
import { useAtomValue } from 'jotai';
import { incomingCallsAtom } from '../state/incomingCalls';
import { isNativePlatform } from '../utils/capacitor';

// When the in-app incomingCallsAtom drops an entry (user accepted, declined,
// other device joined, lifetime expired), also clear the CallStyle notification
// the native service posted for that room. The AlarmManager fallback in the
// Java service handles killed-process dismiss on lifetime expiry; this hook
// covers the live-client paths where JS knows the truth sooner than the alarm.
export const useDismissNativeCallNotifications = (): void => {
  const incoming = useAtomValue(incomingCallsAtom);
  const prevRoomsRef = useRef<Set<string>>(new Set());

  useEffect(() => {
    const nextRooms = new Set<string>();
    incoming.forEach((call) => nextRooms.add(call.roomId));

    const dropped: string[] = [];
    prevRoomsRef.current.forEach((roomId) => {
      if (!nextRooms.has(roomId)) dropped.push(roomId);
    });
    prevRoomsRef.current = nextRooms;

    if (dropped.length === 0) return;
    if (!isNativePlatform()) return;

    (async () => {
      const { PushNotifications } = await import('@capacitor/push-notifications');
      // Shape mirrors VojoFirebaseMessagingService.showIncomingCallNotification:
      //   tag = "call_" + roomId, id = tag.hashCode(). The Android Capacitor
      //   plugin reads id via JSObject.getInteger (PushNotificationsPlugin.java
      //   line 166), so the id must go over the bridge as a number — the TS
      //   type declares string, hence the cast.
      const notifications = dropped.map((roomId) => {
        const tag = `call_${roomId}`;
        return { id: javaStringHashCode(tag), tag };
      });
      await PushNotifications.removeDeliveredNotifications({
        notifications: notifications as unknown as Parameters<
          typeof PushNotifications.removeDeliveredNotifications
        >[0]['notifications'],
      }).catch(() => {
        /* best-effort — alarm fallback still dismisses at lifetime expiry */
      });
    })();
  }, [incoming]);
};

// Reproduces java.lang.String#hashCode so JS-side ids match the tag ids the
// Java service computed. Must stay in sync with CallCancelReceiver / the
// tag.hashCode() call in VojoFirebaseMessagingService.
function javaStringHashCode(s: string): number {
  let h = 0;
  for (let i = 0; i < s.length; i += 1) {
    // eslint-disable-next-line no-bitwise
    h = (Math.imul(31, h) + s.charCodeAt(i)) | 0;
  }
  return h;
}