filterFriends.js

function filterFriends(friends, id, status) {
    const nextStatus = status === 'available' ? 'unavailable' : 'available';
    const online = [];
    const offlineFriends = friends.filter((friend) => {
        if (friend.contact_uuid !== id && friend.status !== status) {
            friend.status = nextStatus;
            return true;
        }
        friend.status = status;
        online.push(friend);
        return false;
    });
    return {
        online,
        offlineFriends,
        available: online.length
    };
}