/*
 * 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.lucene.sandbox.search;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

/** QueryLeafProfilerAggregator that aggregates leaf breakdowns at thread level */
class QueryLeafProfilerThreadAggregator {
  private final ConcurrentMap<Thread, QueryLeafProfilerBreakdown> queryThreadBreakdowns;
  private long queryStartTime = Long.MAX_VALUE;
  private long queryTotalTime = 0;

  public QueryLeafProfilerThreadAggregator() {
    queryThreadBreakdowns = new ConcurrentHashMap<>();
  }

  public long getQueryStartTime() {
    return queryStartTime;
  }

  public long getQueryTotalTime() {
    return queryTotalTime;
  }

  private QueryLeafProfilerBreakdown getQueryThreadProfilerBreakdown() {
    final Thread currentThread = Thread.currentThread();
    // See please https://bugs.openjdk.java.net/browse/JDK-8161372
    final QueryLeafProfilerBreakdown profilerBreakdown = queryThreadBreakdowns.get(currentThread);

    if (profilerBreakdown != null) {
      return profilerBreakdown;
    }

    return queryThreadBreakdowns.computeIfAbsent(
        currentThread, unused -> new QueryLeafProfilerBreakdown());
  }

  public QueryProfilerTimer getTimer(QueryProfilerTimingType timingType) {
    assert timingType.isLeafLevel();

    return getQueryThreadProfilerBreakdown().getTimer(timingType);
  }

  public List<AggregatedQueryLeafProfilerResult> getAggregatedQueryLeafProfilerResults() {
    final List<AggregatedQueryLeafProfilerResult> profilerResults = new ArrayList<>();
    for (Thread thread : queryThreadBreakdowns.keySet()) {
      final AggregatedQueryLeafProfilerResult aggregatedQueryLeafProfilerResult =
          queryThreadBreakdowns.get(thread).getLeafProfilerResult(thread);
      queryStartTime = Math.min(queryStartTime, aggregatedQueryLeafProfilerResult.getStartTime());
      queryTotalTime += aggregatedQueryLeafProfilerResult.getTotalTime();
      profilerResults.add(aggregatedQueryLeafProfilerResult);
    }

    return profilerResults;
  }
}
