cinny/src/app/utils/callRing.ts

import { JoinRule, Room } from 'matrix-js-sdk';
import { StateEvent } from '../../types/matrix/room';
import { getStateEvents } from './room';

/**
 * Whether a call notification in this room may ring — and, by the same rule,
 * whether an unanswered one may show as "Missed call" (Gitea #162 follow-up).
 * Only DMs and invite-only groups outside any space ring, i.e. rooms where the
 * call button is shown. Persistent voice rooms, space channels, restricted and
 * public rooms never do: joining a voice channel alone is normal and isn't a
 * "call" anyone missed.
 */
export const isRingableRoom = (room: Room, isDirect: boolean): boolean => {
  if (room.isCallRoom()) return false;
  if (isDirect) return true;
  const isSpaceChild = getStateEvents(room, StateEvent.SpaceParent).length > 0;
  return !isSpaceChild && room.getJoinRule() === JoinRule.Invite;
};

/** A call-membership state event that is still "in the call" (left = empty content). */
const isActiveMembership = (content: Record<string, unknown> | undefined): boolean =>
  !!content &&
  (typeof content.application === 'string' ||
    (Array.isArray(content.memberships) && content.memberships.length > 0));

/**
 * [Gitea #312] Whether `userId` is in a call in `room` according to the room's
 * current STATE. After a reload the MatrixRTC session can be stale (a join and
 * leave replayed in one catch-up batch), but the state is right.
 */
export const hasActiveCallMembership = (room: Room, userId: string): boolean =>
  getStateEvents(room, StateEvent.GroupCallMemberPrefix).some(
    (ev) =>
      (ev.getSender() === userId || ev.getStateKey()?.includes(userId)) &&
      isActiveMembership(ev.getContent()),
  );

/**
 * [Gitea #312] Whether we already handled the ring `refEventId` points at:
 * declined it (our own RTCDecline relates to it) — e.g. replayed together with
 * the ring in the first sync after a restart, before any dismiss listener.
 */
export const declinedRing = (room: Room, refEventId: string, myUserId: string): boolean =>
  room
    .getLiveTimeline()
    .getEvents()
    .some(
      (ev) =>
        ev.getType() === 'org.matrix.msc4310.rtc.decline' &&
        ev.getSender() === myUserId &&
        ev.getRelation()?.event_id === refEventId,
    );