export function addStatementStats(a: StatementStatistics, b: StatementStatistics) {
  const countA = FixLong(a.count).toInt();
  const countB = FixLong(b.count).toInt();
  return {
    count: a.count.add(b.count),
    first_attempt_count: a.first_attempt_count.add(b.first_attempt_count),
    max_retries: a.max_retries.greaterThan(b.max_retries) ? a.max_retries : b.max_retries,
    num_rows: addNumericStats(a.num_rows, b.num_rows, countA, countB),
    parse_lat: addNumericStats(a.parse_lat, b.parse_lat, countA, countB),
    plan_lat: addNumericStats(a.plan_lat, b.plan_lat, countA, countB),
    run_lat: addNumericStats(a.run_lat, b.run_lat, countA, countB),
    service_lat: addNumericStats(a.service_lat, b.service_lat, countA, countB),
    overhead_lat: addNumericStats(a.overhead_lat, b.overhead_lat, countA, countB),
  };
}

export function IsLeader(info: protos.cockroach.server.serverpb.RangeInfo$Properties) {
  const localRep = GetLocalReplica(info);
  if (_.isNil(localRep)) {
    return false;
  }
  return Long.fromInt(localRep.replica_id).eq(FixLong(info.raft_state.lead));
}

export function getRangeLog(
  req: RangeLogRequestMessage,
  timeout?: moment.Duration,
): Promise<RangeLogResponseMessage> {
  const rangeID = FixLong(req.range_id);
  const rangeIDQuery = (rangeID.eq(0)) ? "" : `/${rangeID.toString()}`;
  const limit = (!_.isNil(req.limit)) ? `?limit=${req.limit}` : "";
  return timeoutFetch(
    serverpb.RangeLogResponse,
    `${API_PREFIX}/rangelog${rangeIDQuery}${limit}`,
    null,
    timeout,
  );
}

export function IsLeaseEpoch(lease: protos.cockroach.roachpb.ILease) {
  return !FixLong(lease.epoch).eq(0);
}

export function stdDevLong(stat: NumericStat, count: number | Long) {
  return stdDev(stat, FixLong(count).toInt());
}