import { useEffect } from 'react';
import { useAtomValue } from 'jotai';
import { MatrixEvent, Room, RoomEvent } from 'matrix-js-sdk';
import { useMatrixClient } from '../hooks/useMatrixClient';
import { searchCacheEnabledAtom } from '../state/searchCacheEnabled';
import { clearRoom, deleteRow } from './searchCache';

/**
 * Gitea #14 — the persistent search cache (`searchCache.ts`) had no
 * invalidation path other than logout or the manual "Clear cached index"
 * button, so redacted messages and rooms the user left kept their decrypted
 * plaintext searchable on disk indefinitely.
 *
 * While the cache is enabled, listen client-wide for redactions (delete the
 * redacted row) and for leaving/being banned from a room (wipe the room's
 * cached rows via the existing `clearRoom`).
 */
export const useSearchCacheInvalidation = (): void => {
  const mx = useMatrixClient();
  const cacheEnabled = useAtomValue(searchCacheEnabledAtom);

  useEffect(() => {
    if (!cacheEnabled) return undefined;

    const onRedaction = (event: MatrixEvent, room: Room) => {
      const redactedEventId = event.getAssociatedId();
      if (redactedEventId) deleteRow(room.roomId, redactedEventId);
    };

    const onMyMembership = (room: Room, membership: string) => {
      if (membership === 'leave' || membership === 'ban') {
        clearRoom(room.roomId);
      }
    };

    mx.on(RoomEvent.Redaction, onRedaction);
    mx.on(RoomEvent.MyMembership, onMyMembership);
    return () => {
      mx.off(RoomEvent.Redaction, onRedaction);
      mx.off(RoomEvent.MyMembership, onMyMembership);
    };
  }, [mx, cacheEnabled]);
};