def create_or_update_client(client_mac_int, base_station, timestamp):
client = get_client_with_mac(client_mac_int)
if client is None:
client = Client(mac=client_mac_int, first_seen=timestamp, last_seen=timestamp,
base_stations=[base_station.key()])
else:
client.last_seen = timestamp
if base_station.key() not in client.base_stations:
client.base_stations.append(base_station.key())
client.put()
return client
