/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.beam.sdk.extensions.euphoria.core.testkit.accumulators;

import java.time.Duration;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import org.apache.beam.sdk.extensions.euphoria.core.client.accumulators.Timer;
import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.Maps;

final class NanosecondTimer implements Timer, Snapshotable<Map<Duration, Long>> {

  private final LongHistogram hist = new LongHistogram();

  NanosecondTimer() {}

  @Override
  public void add(long duration, TimeUnit unit) {
    hist.add(unit.toNanos(duration), 1);
  }

  @Override
  public void add(Duration duration) {
    add(duration.toNanos(), TimeUnit.NANOSECONDS);
  }

  @Override
  public Map<Duration, Long> getSnapshot() {
    Map<Duration, Long> m = Maps.newHashMapWithExpectedSize(hist.buckets.size());
    hist.buckets.forEach((key, count) -> m.put(Duration.ofNanos(key), count));
    return m;
  }
}
