/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0 and the Server Side Public License, v 1; you may not use this file except
 * in compliance with, at your election, the Elastic License 2.0 or the Server
 * Side Public License, v 1.
 */

package org.elasticsearch.action.search;

import org.elasticsearch.action.ActionListener;
import org.elasticsearch.action.support.ActionFilters;
import org.elasticsearch.client.internal.node.NodeClient;
import org.elasticsearch.cluster.ClusterName;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.service.ClusterService;
import org.elasticsearch.common.Randomness;
import org.elasticsearch.common.UUIDs;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.util.concurrent.AtomicArray;
import org.elasticsearch.search.internal.InternalSearchResponse;
import org.elasticsearch.tasks.Task;
import org.elasticsearch.test.ESTestCase;
import org.elasticsearch.threadpool.TestThreadPool;
import org.elasticsearch.threadpool.ThreadPool;
import org.elasticsearch.transport.Transport;
import org.elasticsearch.transport.TransportService;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;

import java.util.Arrays;
import java.util.Collections;
import java.util.HashSet;
import java.util.IdentityHashMap;
import java.util.List;
import java.util.Queue;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;

import static org.elasticsearch.test.ClusterServiceUtils.createClusterService;
import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.Matchers.greaterThanOrEqualTo;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

/**
 * MultiSearch took time tests
 */
public class MultiSearchActionTookTests extends ESTestCase {

    private ThreadPool threadPool;
    private ClusterService clusterService;

    @BeforeClass
    public static void beforeClass() {}

    @AfterClass
    public static void afterClass() {}

    @Before
    public void setUp() throws Exception {
        super.setUp();
        threadPool = new TestThreadPool("MultiSearchActionTookTests");
        clusterService = createClusterService(threadPool);
    }

    @After
    public void tearDown() throws Exception {
        clusterService.close();
        ThreadPool.terminate(threadPool, 30, TimeUnit.SECONDS);
        super.tearDown();
    }

    // test unit conversion using a controller clock
    public void testTookWithControlledClock() throws Exception {
        runTestTook(true);
    }

    // test using System#nanoTime
    public void testTookWithRealClock() throws Exception {
        runTestTook(false);
    }

    private void runTestTook(boolean controlledClock) throws Exception {
        MultiSearchRequest multiSearchRequest = new MultiSearchRequest().add(new SearchRequest());
        AtomicLong expected = new AtomicLong();

        TransportMultiSearchAction action = createTransportMultiSearchAction(controlledClock, expected);

        action.doExecute(mock(Task.class), multiSearchRequest, new ActionListener<MultiSearchResponse>() {
            @Override
            public void onResponse(MultiSearchResponse multiSearchResponse) {
                if (controlledClock) {
                    assertThat(
                        TimeUnit.MILLISECONDS.convert(expected.get(), TimeUnit.NANOSECONDS),
                        equalTo(multiSearchResponse.getTook().getMillis())
                    );
                } else {
                    assertThat(
                        multiSearchResponse.getTook().getMillis(),
                        greaterThanOrEqualTo(TimeUnit.MILLISECONDS.convert(expected.get(), TimeUnit.NANOSECONDS))
                    );
                }
            }

            @Override
            public void onFailure(Exception e) {
                throw new RuntimeException(e);
            }
        });
    }

    private TransportMultiSearchAction createTransportMultiSearchAction(boolean controlledClock, AtomicLong expected) {
        Settings settings = Settings.builder().put("node.name", TransportMultiSearchActionTests.class.getSimpleName()).build();
        TransportService transportService = new TransportService(
            Settings.EMPTY,
            mock(Transport.class),
            threadPool,
            TransportService.NOOP_TRANSPORT_INTERCEPTOR,
            boundAddress -> DiscoveryNode.createLocal(settings, boundAddress.publishAddress(), UUIDs.randomBase64UUID()),
            null,
            Collections.emptySet()
        );
        ActionFilters actionFilters = new ActionFilters(new HashSet<>());
        ClusterService clusterService = mock(ClusterService.class);
        when(clusterService.state()).thenReturn(ClusterState.builder(new ClusterName("test")).build());

        final int availableProcessors = Runtime.getRuntime().availableProcessors();
        AtomicInteger counter = new AtomicInteger();
        final List<String> threadPoolNames = Arrays.asList(ThreadPool.Names.GENERIC, ThreadPool.Names.SAME);
        Randomness.shuffle(threadPoolNames);
        final ExecutorService commonExecutor = threadPool.executor(threadPoolNames.get(0));
        final Set<SearchRequest> requests = Collections.newSetFromMap(Collections.synchronizedMap(new IdentityHashMap<>()));

        NodeClient client = new NodeClient(settings, threadPool) {
            @Override
            public void search(final SearchRequest request, final ActionListener<SearchResponse> listener) {
                requests.add(request);
                commonExecutor.execute(() -> {
                    counter.decrementAndGet();
                    listener.onResponse(
                        new SearchResponse(
                            InternalSearchResponse.EMPTY_WITH_TOTAL_HITS,
                            null,
                            0,
                            0,
                            0,
                            0L,
                            ShardSearchFailure.EMPTY_ARRAY,
                            SearchResponse.Clusters.EMPTY
                        )
                    );
                });
            }

            @Override
            public String getLocalNodeId() {
                return "local_node_id";
            }
        };

        if (controlledClock) {
            return new TransportMultiSearchAction(
                threadPool,
                actionFilters,
                transportService,
                clusterService,
                availableProcessors,
                expected::get,
                client
            ) {
                @Override
                void executeSearch(
                    final Queue<SearchRequestSlot> requests,
                    final AtomicArray<MultiSearchResponse.Item> responses,
                    final AtomicInteger responseCounter,
                    final ActionListener<MultiSearchResponse> listener,
                    long startTimeInNanos
                ) {
                    expected.set(1000000);
                    super.executeSearch(requests, responses, responseCounter, listener, startTimeInNanos);
                }
            };
        } else {
            return new TransportMultiSearchAction(
                threadPool,
                actionFilters,
                transportService,
                clusterService,
                availableProcessors,
                System::nanoTime,
                client
            ) {
                @Override
                void executeSearch(
                    final Queue<SearchRequestSlot> requests,
                    final AtomicArray<MultiSearchResponse.Item> responses,
                    final AtomicInteger responseCounter,
                    final ActionListener<MultiSearchResponse> listener,
                    long startTimeInNanos
                ) {
                    long elapsed = spinForAtLeastNMilliseconds(randomIntBetween(0, 10));
                    expected.set(elapsed);
                    super.executeSearch(requests, responses, responseCounter, listener, startTimeInNanos);
                }
            };
        }
    }
}
