export interface FriendAvatarSource {
  user_id: string;
  topic?: string;
  avatar_file_id?: string;
}

/**
 * P2P contacts are keyed by their `p2p...` topic after the first subscription,
 * while the friends API identifies the same person with a `usr...` user ID.
 * Keep both aliases so avatars work during both the initial and established
 * conversation states.
 */
export function friendAvatarLookup(friends: FriendAvatarSource[] = []) {
  const avatars = new Map<string, string | undefined>();
  for (const friend of friends) {
    if (friend.user_id) avatars.set(friend.user_id, friend.avatar_file_id);
    if (friend.topic) avatars.set(friend.topic, friend.avatar_file_id);
  }
  return avatars;
}