import { MatrixClient, Room, RoomEvent } from 'matrix-js-sdk';
import { useEffect } from 'react';
import { AccountDataEvent } from '../../types/matrix/accountData';
import { Membership } from '../../types/matrix/room';
import { getAccountData, getMDirects, isBridgedRoom } from '../utils/room';
import { addRoomIdToMDirect } from '../utils/matrix';

export function useAutoDirectSync(mx: MatrixClient): void {
  useEffect(() => {
    const handleMembership = (room: Room, _membership: string, prevMembership?: string) => {
      if (prevMembership !== Membership.Invite) return;
      if (room.getMyMembership() !== Membership.Join) return;

      const dmInviter = room.getDMInviter();
      if (!dmInviter) return;

      const joinedAndInvited = room.getJoinedMemberCount() + room.getInvitedMemberCount();
      if (joinedAndInvited > 2) return;

      // Bridged portal rooms (mautrix-telegram/whatsapp/discord/…) live in the
      // per-bridge personal filtering space (Channels tab) — don't pollute
      // `m.direct` with them. `useDirectRooms` already filters bridged rooms
      // out of the Direct tab visually; this prevents the underlying account
      // data from accruing stale entries for other clients to misclassify.
      if (isBridgedRoom(room)) return;

      const mDirectEvent = getAccountData(mx, AccountDataEvent.Direct);
      if (mDirectEvent) {
        const directs = getMDirects(mDirectEvent);
        if (directs.has(room.roomId)) return;
      }

      addRoomIdToMDirect(mx, room.roomId, dmInviter).catch(() => undefined);
    };

    mx.on(RoomEvent.MyMembership, handleMembership);
    return () => {
      mx.removeListener(RoomEvent.MyMembership, handleMembership);
    };
  }, [mx]);
}