/*
 * 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.search.query;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.document.KeywordField;
import org.apache.lucene.document.LatLonDocValuesField;
import org.apache.lucene.document.LatLonPoint;
import org.apache.lucene.document.LongPoint;
import org.apache.lucene.document.NumericDocValuesField;
import org.apache.lucene.document.SortedSetDocValuesField;
import org.apache.lucene.document.StringField;
import org.apache.lucene.document.TextField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.index.NoMergePolicy;
import org.apache.lucene.index.Term;
import org.apache.lucene.queries.spans.SpanNearQuery;
import org.apache.lucene.queries.spans.SpanTermQuery;
import org.apache.lucene.search.BooleanClause.Occur;
import org.apache.lucene.search.BooleanQuery;
import org.apache.lucene.search.Collector;
import org.apache.lucene.search.CollectorManager;
import org.apache.lucene.search.ConstantScoreQuery;
import org.apache.lucene.search.FieldComparator;
import org.apache.lucene.search.FieldDoc;
import org.apache.lucene.search.FieldExistsQuery;
import org.apache.lucene.search.FilterCollector;
import org.apache.lucene.search.FilterLeafCollector;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.LeafCollector;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.search.MatchNoDocsQuery;
import org.apache.lucene.search.MultiTermQuery;
import org.apache.lucene.search.PrefixQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.QueryCachingPolicy;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopDocs;
import org.apache.lucene.search.TotalHits;
import org.apache.lucene.search.Weight;
import org.apache.lucene.search.join.BitSetProducer;
import org.apache.lucene.search.join.ScoreMode;
import org.apache.lucene.store.Directory;
import org.apache.lucene.tests.index.RandomIndexWriter;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.FixedBitSet;
import org.elasticsearch.action.search.SearchShardTask;
import org.elasticsearch.index.mapper.DateFieldMapper;
import org.elasticsearch.index.mapper.MappedFieldType;
import org.elasticsearch.index.mapper.NumberFieldMapper;
import org.elasticsearch.index.query.ParsedQuery;
import org.elasticsearch.index.query.SearchExecutionContext;
import org.elasticsearch.index.search.ESToParentBlockJoinQuery;
import org.elasticsearch.index.shard.IndexShard;
import org.elasticsearch.index.shard.IndexShardTestCase;
import org.elasticsearch.lucene.queries.MinDocQuery;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.aggregations.AggregatorFactories;
import org.elasticsearch.search.aggregations.SearchContextAggregations;
import org.elasticsearch.search.internal.ContextIndexSearcher;
import org.elasticsearch.search.internal.ReaderContext;
import org.elasticsearch.search.internal.ScrollContext;
import org.elasticsearch.search.internal.SearchContext;
import org.elasticsearch.search.internal.ShardSearchContextId;
import org.elasticsearch.search.rank.RankShardContext;
import org.elasticsearch.search.rank.RankShardResult;
import org.elasticsearch.search.sort.SortAndFormats;
import org.elasticsearch.tasks.TaskCancelHelper;
import org.elasticsearch.tasks.TaskCancelledException;
import org.elasticsearch.tasks.TaskId;
import org.elasticsearch.test.TestSearchContext;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import static org.elasticsearch.search.query.TopDocsCollectorManagerFactory.hasInfMaxScore;
import static org.hamcrest.Matchers.anyOf;
import static org.hamcrest.Matchers.arrayWithSize;
import static org.hamcrest.Matchers.either;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.greaterThan;
import static org.hamcrest.Matchers.greaterThanOrEqualTo;
import static org.hamcrest.Matchers.instanceOf;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.lessThan;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

public class QueryPhaseTests extends IndexShardTestCase {

    private Directory dir;
    private IndexReader reader;
    private IndexShard indexShard;

    @Override
    public void setUp() throws Exception {
        super.setUp();
        dir = newDirectory();
        indexShard = newShard(true);
    }

    @Override
    public void tearDown() throws Exception {
        super.tearDown();
        if (reader != null) {
            reader.close();
        }
        dir.close();
        closeShards(indexShard);
    }

    private TestSearchContext createContext(ContextIndexSearcher searcher, Query query) {
        TestSearchContext context = new TestSearchContext(null, indexShard, searcher);
        context.setTask(new SearchShardTask(123L, "", "", "", null, Collections.emptyMap()));
        context.parsedQuery(new ParsedQuery(query));
        return context;
    }

    private void countTestCase(Query query, IndexReader reader, boolean shouldCollectSearch, boolean shouldCollectCount) throws Exception {
        ContextIndexSearcher searcher = shouldCollectSearch ? newContextSearcher(reader) : noCollectionContextSearcher(reader);
        TestSearchContext context = createContext(searcher, query);
        context.setSize(0);

        QueryPhase.addCollectorsAndSearch(context);

        ContextIndexSearcher countSearcher = shouldCollectCount ? newContextSearcher(reader) : noCollectionContextSearcher(reader);
        assertEquals(countSearcher.count(query), context.queryResult().topDocs().topDocs.totalHits.value);
    }

    private void countTestCase(boolean withDeletions) throws Exception {
        IndexWriterConfig iwc = newIndexWriterConfig().setMergePolicy(NoMergePolicy.INSTANCE);
        RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);
        final int numDocs = scaledRandomIntBetween(100, 200);
        for (int i = 0; i < numDocs; ++i) {
            Document doc = new Document();
            if (randomBoolean()) {
                doc.add(new StringField("foo", "bar", Store.NO));
                doc.add(new SortedSetDocValuesField("foo", new BytesRef("bar")));
                doc.add(new SortedSetDocValuesField("docValuesOnlyField", new BytesRef("bar")));
                doc.add(new LatLonDocValuesField("latLonDVField", 1.0, 1.0));
                doc.add(new LatLonPoint("latLonDVField", 1.0, 1.0));
            }
            if (randomBoolean()) {
                doc.add(new StringField("foo", "baz", Store.NO));
                doc.add(new SortedSetDocValuesField("foo", new BytesRef("baz")));
            }
            if (withDeletions && (rarely() || i == 0)) {
                doc.add(new StringField("delete", "yes", Store.NO));
            }
            w.addDocument(doc);
        }
        if (withDeletions) {
            w.deleteDocuments(new Term("delete", "yes"));
        }
        reader = w.getReader();
        Query matchAll = new MatchAllDocsQuery();
        Query matchAllCsq = new ConstantScoreQuery(matchAll);
        Query tq = new TermQuery(new Term("foo", "bar"));
        Query tCsq = new ConstantScoreQuery(tq);
        Query feq = new FieldExistsQuery("foo");
        Query feq_points = new FieldExistsQuery("latLonDVField");
        Query feqCsq = new ConstantScoreQuery(feq);
        // field with doc-values but not indexed will need to collect
        Query dvOnlyfeq = new FieldExistsQuery("docValuesOnlyField");
        BooleanQuery bq = new BooleanQuery.Builder().add(matchAll, Occur.SHOULD).add(tq, Occur.MUST).build();

        countTestCase(matchAll, reader, false, false);
        countTestCase(matchAllCsq, reader, false, false);
        countTestCase(tq, reader, withDeletions, withDeletions);
        countTestCase(tCsq, reader, withDeletions, withDeletions);
        countTestCase(feq, reader, withDeletions, true);
        countTestCase(feq_points, reader, withDeletions, true);
        countTestCase(feqCsq, reader, withDeletions, true);
        countTestCase(dvOnlyfeq, reader, true, true);
        countTestCase(bq, reader, true, true);
        w.close();
    }

    public void testCountWithoutDeletions() throws Exception {
        countTestCase(false);
    }

    public void testCountWithDeletions() throws Exception {
        countTestCase(true);
    }

    private int indexDocs() throws IOException {
        return indexDocs(newIndexWriterConfig());
    }

    private int indexDocs(IndexWriterConfig iwc) throws IOException {
        RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);
        final int numDocs = scaledRandomIntBetween(100, 200);
        for (int i = 0; i < numDocs; ++i) {
            Document doc = new Document();
            if (randomBoolean()) {
                doc.add(new StringField("foo", "bar", Store.NO));
            }
            if (randomBoolean()) {
                doc.add(new StringField("foo", "baz", Store.NO));
            }
            doc.add(new NumericDocValuesField("rank", numDocs - i));
            w.addDocument(doc);
        }
        w.close();
        reader = DirectoryReader.open(dir);
        return numDocs;
    }

    public void testPostFilterDisablesHitCountShortcut() throws Exception {
        int numDocs = indexDocs();
        {
            TestSearchContext context = createContext(noCollectionContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(0);
            QueryPhase.addCollectorsAndSearch(context);
            assertEquals(numDocs, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        }
        {
            // shortcutTotalHitCount makes us not track total hits as part of the top docs collection, hence size is the threshold
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 10), new MatchAllDocsQuery());
            context.setSize(10);
            QueryPhase.addCollectorsAndSearch(context);
            assertEquals(numDocs, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        }
        {
            // QueryPhaseCollector does not propagate Weight#count when a post_filter is provided, hence it forces collection despite
            // the inner TotalHitCountCollector can shortcut
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(0);
            context.parsedPostFilter(new ParsedQuery(new MatchNoDocsQuery()));
            QueryPhase.executeQuery(context);
            assertEquals(0, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        }
        {
            // shortcutTotalHitCount is disabled for filter collectors, hence we collect until track_total_hits
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(10);
            context.parsedPostFilter(new ParsedQuery(new MatchNoDocsQuery()));
            QueryPhase.addCollectorsAndSearch(context);
            assertEquals(0, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        }
    }

    public void testTerminateAfterWithFilter() throws Exception {
        indexDocs();
        TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
        context.terminateAfter(1);
        context.setSize(10);
        context.parsedPostFilter(new ParsedQuery(new TermQuery(new Term("foo", "bar"))));
        QueryPhase.addCollectorsAndSearch(context);
        assertEquals(1, context.queryResult().topDocs().topDocs.totalHits.value);
        assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(1));
    }

    public void testMinScoreDisablesHitCountShortcut() throws Exception {
        int numDocs = indexDocs();
        {
            TestSearchContext context = createContext(noCollectionContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(0);
            QueryPhase.addCollectorsAndSearch(context);
            assertEquals(numDocs, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        }
        {
            // shortcutTotalHitCount makes us not track total hits as part of the top docs collection, hence size is the threshold
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 10), new MatchAllDocsQuery());
            context.setSize(10);
            QueryPhase.addCollectorsAndSearch(context);
            assertEquals(numDocs, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        }
        {
            // QueryPhaseCollector does not propagate Weight#count when min_score is provided, hence it forces collection despite
            // the inner TotalHitCountCollector can shortcut
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(0);
            context.minimumScore(100);
            QueryPhase.addCollectorsAndSearch(context);
            assertEquals(0, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        }
        {
            // shortcutTotalHitCount is disabled for filter collectors, hence we collect until track_total_hits
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(10);
            context.minimumScore(100);
            QueryPhase.executeQuery(context);
            assertEquals(0, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        }
    }

    public void testQueryCapturesThreadPoolStats() throws Exception {
        indexDocs();
        TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
        QueryPhase.addCollectorsAndSearch(context);
        QuerySearchResult results = context.queryResult();
        assertThat(results.serviceTimeEWMA(), greaterThanOrEqualTo(0L));
        assertThat(results.nodeQueueSize(), greaterThanOrEqualTo(0));
    }

    public void testInOrderScrollOptimization() throws Exception {
        final Sort sort = new Sort(new SortField("not_present", SortField.Type.INT));
        IndexWriterConfig iwc = newIndexWriterConfig().setIndexSort(sort);
        int numDocs = indexDocs(iwc);

        ScrollContext scrollContext = new ScrollContext();
        TestSearchContext context = new TestSearchContext(null, indexShard, newContextSearcher(reader), scrollContext);
        context.setTask(new SearchShardTask(123L, "", "", "", null, Collections.emptyMap()));
        context.parsedQuery(new ParsedQuery(new MatchAllDocsQuery()));
        context.sort(new SortAndFormats(sort, new DocValueFormat[] { DocValueFormat.RAW }));
        scrollContext.lastEmittedDoc = null;
        scrollContext.maxScore = Float.NaN;
        scrollContext.totalHits = null;
        int size = randomIntBetween(2, 5);
        context.setSize(size);

        QueryPhase.addCollectorsAndSearch(context);
        assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
        assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        assertNull(context.queryResult().terminatedEarly());
        assertThat(context.terminateAfter(), equalTo(0));
        assertThat(context.queryResult().getTotalHits().value, equalTo((long) numDocs));

        context.setSearcher(earlyTerminationContextSearcher(reader, size));
        QueryPhase.addCollectorsAndSearch(context);
        assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
        assertThat(context.queryResult().getTotalHits().value, equalTo((long) numDocs));
        assertEquals(TotalHits.Relation.EQUAL_TO, context.queryResult().topDocs().topDocs.totalHits.relation);
        assertThat(context.queryResult().topDocs().topDocs.scoreDocs[0].doc, greaterThanOrEqualTo(size));
    }

    /**
     * Test the terminate after functionality when no hits are collected (size is set to 0) and the total hit count is shortcut by
     * {@link org.apache.lucene.search.TotalHitCountCollector} using {@link Weight#count(LeafReaderContext)}. A match all query is used
     * to leverage the hit count shortcut as it enables retrieving the count from the index statistics. Terminate_after has no effect as
     * there is no collection effectively. It is fine that the total hit count is higher than the provided threshold in this case.
     */
    public void testTerminateAfterSize0HitCountShortcut() throws Exception {
        int numDocs = indexDocs();
        {
            TestSearchContext context = createContext(noCollectionContextSearcher(reader), new MatchAllDocsQuery());
            context.terminateAfter(1);
            context.setSize(0);
            QueryPhase.addCollectorsAndSearch(context);
            assertFalse(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(0));
        }
        // test interaction between trackTotalHits and terminateAfter
        {
            TestSearchContext context = createContext(noCollectionContextSearcher(reader), new MatchAllDocsQuery());
            context.terminateAfter(10);
            context.setSize(0);
            context.trackTotalHitsUpTo(-1);
            QueryPhase.executeQuery(context);
            assertFalse(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(0L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(0));
        }
        {
            TestSearchContext context = createContext(noCollectionContextSearcher(reader), new MatchAllDocsQuery());
            context.terminateAfter(10);
            context.setSize(0);
            // terminate_after is not honored, no matter the value of track_total_hits.
            context.trackTotalHitsUpTo(randomIntBetween(1, Integer.MAX_VALUE));
            QueryPhase.executeQuery(context);
            assertFalse(context.queryResult().terminatedEarly());
            // Given that total hit count does not require collection, PartialHitCountCollector does not early terminate.
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(0));
        }
    }

    /**
     * Test the terminate after functionality when no hits are collected (size is set to 0) and the
     * total hit count cannot be shortcut using {@link Weight#count(LeafReaderContext)}.
     * We use a special term query that doesn't expose doc count via Weight#count, which makes it impossible to shortcut the hit count.
     * This test also requires disabling the query cache or the count could be cached from previous runs and cause different behaviour.
     */
    public void testTerminateAfterSize0NoHitCountShortcut() throws Exception {
        indexDocs();
        Query query = new NonCountingTermQuery(new Term("foo", "bar"));
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 1), query);
            context.terminateAfter(1);
            context.setSize(0);
            QueryPhase.executeQuery(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(1L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(0));
        }
        // test interaction between trackTotalHits and terminateAfter
        {
            TestSearchContext context = createContext(noCollectionContextSearcher(reader), query);
            context.terminateAfter(10);
            context.setSize(0);
            // not tracking total hits makes the hit count collection early terminate, in which case terminate_after can't be honored
            context.trackTotalHitsUpTo(-1);
            QueryPhase.executeQuery(context);
            assertFalse(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(0L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(0));
        }
        {
            // track total hits is lower than terminate_after, hit count collection early terminates, terminate_after is not honored
            // we don't use 9 (terminate_after - 1) because it makes the test unpredictable depending on the number of segments and
            // documents distribution: terminate_after may be honored at time due to the check before pulling each leaf collector.
            int trackTotalHits = randomIntBetween(1, 8);
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, trackTotalHits), query);
            context.terminateAfter(10);
            context.setSize(0);
            context.trackTotalHitsUpTo(trackTotalHits);
            QueryPhase.executeQuery(context);
            assertFalse(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) trackTotalHits));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(0));
        }
        {
            TestSearchContext context = createContext(newContextSearcher(reader), query);
            context.terminateAfter(10);
            context.setSize(0);
            // track total hits is higher than terminate_after, in which case collection effectively terminates after 10 documents
            context.trackTotalHitsUpTo(randomIntBetween(11, Integer.MAX_VALUE));
            QueryPhase.executeQuery(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(10L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(0));
        }
    }

    /**
     * Test the terminate after functionality when hits are collected (size is greater than 0) and the
     * total hit count is shortcut using {@link TopDocsCollectorManagerFactory#shortcutTotalHitCount(IndexReader, Query)}
     * A match all query is used to leverage the hit count shortcut as it enables retrieving the count from the index statistics.
     * Note that track_total_hits is effectively ignored in this case, and the hit count threshold applied is instead <code>size</code>.
     */
    public void testTerminateAfterWithHitsHitCountShortcut() throws Exception {
        int numDocs = indexDocs();
        {
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.terminateAfter(numDocs);
            context.setSize(10);
            QueryPhase.executeQuery(context);
            assertFalse(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(10));
        }
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 1), new MatchAllDocsQuery());
            context.terminateAfter(1);
            // default track_total_hits, size 1: terminate_after kicks in first
            context.setSize(1);
            QueryPhase.addCollectorsAndSearch(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(1));
        }
        // test interaction between trackTotalHits and terminateAfter
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 7), new MatchAllDocsQuery());
            context.terminateAfter(7);
            // total hits tracking disabled but 10 hits need to be collected, terminate_after is lower than size, so it kicks in first
            context.setSize(10);
            context.trackTotalHitsUpTo(-1);
            QueryPhase.executeQuery(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(0L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(7));
        }
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 7), new MatchAllDocsQuery());
            context.terminateAfter(7);
            // size is greater than terminate_after (track_total_hits does not matter): terminate_after kicks in first
            context.setSize(10);
            context.trackTotalHitsUpTo(randomIntBetween(1, Integer.MAX_VALUE));
            QueryPhase.executeQuery(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(7));
        }
        {
            int size = randomIntBetween(1, 6);
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, size), new MatchAllDocsQuery());
            context.terminateAfter(7);
            // size is lower than terminate_after, track_total_hits does not matter: depending on docs distribution we may or may not be
            // able to honor terminate_after. low scoring hits are skipped via setMinCompetitiveScore, which bypasses terminate_after
            // until the next leaf collector is pulled, when that happens.
            context.setSize(size);
            context.trackTotalHitsUpTo(randomIntBetween(1, Integer.MAX_VALUE));
            QueryPhase.executeQuery(context);
            assertThat(context.queryResult().terminatedEarly(), either(is(true)).or(is(false)));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(size));
        }
    }

    /**
     * Test the terminate after functionality when hits are collected (size is greater than 0) and the
     * total hit count cannot be shortcut using {@link TopDocsCollectorManagerFactory#shortcutTotalHitCount(IndexReader, Query)}.
     * We use a boolean query which the shortcutTotalHitCount does not shortcut the hit count for.
     */
    public void testTerminateAfterWithHitsNoHitCountShortcut() throws Exception {
        indexDocs();
        TermQuery query = new NonCountingTermQuery(new Term("foo", "bar"));
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 1), query);
            context.terminateAfter(1);
            context.setSize(1);
            QueryPhase.addCollectorsAndSearch(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(1L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(1));
        }
        // test interaction between trackTotalHits and terminateAfter
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 7), query);
            context.terminateAfter(7);
            context.setSize(10);
            context.trackTotalHitsUpTo(-1);
            QueryPhase.executeQuery(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(0L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(7));
        }
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 7), query);
            context.terminateAfter(7);
            // size is greater than terminate_after
            context.setSize(10);
            // track_total_hits is lower than terminate_after
            context.trackTotalHitsUpTo(randomIntBetween(1, 6));
            QueryPhase.executeQuery(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(7L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(7));
        }
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 7), query);
            context.terminateAfter(7);
            // size is lower than terminate_after
            context.setSize(5);
            // track_total_hits is lower than terminate_after
            context.trackTotalHitsUpTo(randomIntBetween(1, 6));
            QueryPhase.executeQuery(context);
            // depending on docs distribution we may or may not be able to honor terminate_after: low scoring hits are skipped via
            // setMinCompetitiveScore, which bypasses terminate_after until the next leaf collector is pulled, when that happens.
            assertThat(context.queryResult().terminatedEarly(), either(is(true)).or(is(false)));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(7L));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(5));
        }
        {
            TestSearchContext context = createContext(earlyTerminationContextSearcher(reader, 7), query);
            context.terminateAfter(7);
            // size is greater than terminate_after
            context.setSize(10);
            // track_total_hits is also greater than terminate_after
            context.trackTotalHitsUpTo(randomIntBetween(8, Integer.MAX_VALUE));
            QueryPhase.executeQuery(context);
            assertTrue(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(7L));
            // TODO this looks off, it should probably be GREATER_THAN_OR_EQUAL_TO
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(7));
        }
    }

    public void testIndexSortingEarlyTermination() throws Exception {
        final Sort sort = new Sort(new SortField("rank", SortField.Type.INT));
        IndexWriterConfig iwc = newIndexWriterConfig().setIndexSort(sort);
        int numDocs = indexDocs(iwc);
        {
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(1);
            context.sort(new SortAndFormats(sort, new DocValueFormat[] { DocValueFormat.RAW }));
            QueryPhase.addCollectorsAndSearch(context);
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(1));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs[0], instanceOf(FieldDoc.class));
            FieldDoc fieldDoc = (FieldDoc) context.queryResult().topDocs().topDocs.scoreDocs[0];
            assertThat(fieldDoc.fields[0], equalTo(1));
        }
        {
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(1);
            context.sort(new SortAndFormats(sort, new DocValueFormat[] { DocValueFormat.RAW }));
            context.parsedPostFilter(new ParsedQuery(new MinDocQuery(1)));
            QueryPhase.addCollectorsAndSearch(context);
            assertNull(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo(numDocs - 1L));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(1));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs[0], instanceOf(FieldDoc.class));
            FieldDoc fieldDoc = (FieldDoc) context.queryResult().topDocs().topDocs.scoreDocs[0];
            assertThat(fieldDoc.fields[0], anyOf(equalTo(1), equalTo(2)));
        }
        {
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(1);
            context.sort(new SortAndFormats(sort, new DocValueFormat[] { DocValueFormat.RAW }));
            QueryPhase.executeQuery(context);
            assertNull(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(1));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs[0], instanceOf(FieldDoc.class));
            FieldDoc fieldDoc = (FieldDoc) context.queryResult().topDocs().topDocs.scoreDocs[0];
            assertThat(fieldDoc.fields[0], anyOf(equalTo(1), equalTo(2)));
        }
        {
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(1);
            context.sort(new SortAndFormats(sort, new DocValueFormat[] { DocValueFormat.RAW }));
            context.setSearcher(earlyTerminationContextSearcher(reader, 1));
            context.trackTotalHitsUpTo(SearchContext.TRACK_TOTAL_HITS_DISABLED);
            QueryPhase.addCollectorsAndSearch(context);
            assertNull(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(1));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs[0], instanceOf(FieldDoc.class));
            FieldDoc fieldDoc = (FieldDoc) context.queryResult().topDocs().topDocs.scoreDocs[0];
            assertThat(fieldDoc.fields[0], anyOf(equalTo(1), equalTo(2)));
        }
        {
            TestSearchContext context = createContext(newContextSearcher(reader), new MatchAllDocsQuery());
            context.setSize(1);
            context.sort(new SortAndFormats(sort, new DocValueFormat[] { DocValueFormat.RAW }));
            QueryPhase.addCollectorsAndSearch(context);
            assertNull(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(1));
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs[0], instanceOf(FieldDoc.class));
            FieldDoc fieldDoc = (FieldDoc) context.queryResult().topDocs().topDocs.scoreDocs[0];
            assertThat(fieldDoc.fields[0], anyOf(equalTo(1), equalTo(2)));
        }
    }

    public void testIndexSortScrollOptimization() throws Exception {
        final Sort indexSort = new Sort(new SortField("rank", SortField.Type.INT), new SortField("tiebreaker", SortField.Type.INT));
        IndexWriterConfig iwc = newIndexWriterConfig().setIndexSort(indexSort);
        RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);
        final int numDocs = scaledRandomIntBetween(100, 200);
        for (int i = 0; i < numDocs; ++i) {
            Document doc = new Document();
            doc.add(new NumericDocValuesField("rank", random().nextInt()));
            doc.add(new NumericDocValuesField("tiebreaker", i));
            w.addDocument(doc);
        }
        if (randomBoolean()) {
            w.forceMerge(randomIntBetween(1, 10));
        }
        w.close();
        reader = DirectoryReader.open(dir);

        List<SortAndFormats> searchSortAndFormats = new ArrayList<>();
        searchSortAndFormats.add(new SortAndFormats(indexSort, new DocValueFormat[] { DocValueFormat.RAW, DocValueFormat.RAW }));
        // search sort is a prefix of the index sort
        searchSortAndFormats.add(new SortAndFormats(new Sort(indexSort.getSort()[0]), new DocValueFormat[] { DocValueFormat.RAW }));
        for (SortAndFormats searchSortAndFormat : searchSortAndFormats) {
            ScrollContext scrollContext = new ScrollContext();
            TestSearchContext context = new TestSearchContext(null, indexShard, newContextSearcher(reader), scrollContext);
            context.parsedQuery(new ParsedQuery(new MatchAllDocsQuery()));
            scrollContext.lastEmittedDoc = null;
            scrollContext.maxScore = Float.NaN;
            scrollContext.totalHits = null;
            context.setTask(new SearchShardTask(123L, "", "", "", null, Collections.emptyMap()));
            context.setSize(10);
            context.sort(searchSortAndFormat);

            QueryPhase.addCollectorsAndSearch(context);
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertNull(context.queryResult().terminatedEarly());
            assertThat(context.terminateAfter(), equalTo(0));
            assertThat(context.queryResult().getTotalHits().value, equalTo((long) numDocs));
            int sizeMinus1 = context.queryResult().topDocs().topDocs.scoreDocs.length - 1;
            FieldDoc lastDoc = (FieldDoc) context.queryResult().topDocs().topDocs.scoreDocs[sizeMinus1];

            context.setSearcher(earlyTerminationContextSearcher(reader, 10));
            QueryPhase.addCollectorsAndSearch(context);
            assertNull(context.queryResult().terminatedEarly());
            assertThat(context.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(context.terminateAfter(), equalTo(0));
            assertThat(context.queryResult().getTotalHits().value, equalTo((long) numDocs));
            FieldDoc firstDoc = (FieldDoc) context.queryResult().topDocs().topDocs.scoreDocs[0];
            for (int i = 0; i < searchSortAndFormat.sort.getSort().length; i++) {
                @SuppressWarnings("unchecked")
                FieldComparator<Object> comparator = (FieldComparator<Object>) searchSortAndFormat.sort.getSort()[i].getComparator(
                    1,
                    i == 0
                );
                int cmp = comparator.compareValues(firstDoc.fields[i], lastDoc.fields[i]);
                if (cmp == 0) {
                    continue;
                }
                assertThat(cmp, equalTo(1));
                break;
            }
        }
    }

    public void testDisableTopScoreCollection() throws Exception {
        IndexWriterConfig iwc = newIndexWriterConfig(new StandardAnalyzer());
        RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);
        Document doc = new Document();
        for (int i = 0; i < 10; i++) {
            doc.clear();
            if (i % 2 == 0) {
                doc.add(new TextField("title", "foo bar", Store.NO));
            } else {
                doc.add(new TextField("title", "foo", Store.NO));
            }
            w.addDocument(doc);
        }
        w.close();
        reader = DirectoryReader.open(dir);

        Query q = new SpanNearQuery.Builder("title", true).addClause(new SpanTermQuery(new Term("title", "foo")))
            .addClause(new SpanTermQuery(new Term("title", "bar")))
            .build();
        {
            TestSearchContext context = createContext(newContextSearcher(reader), q);
            context.setSize(3);
            context.trackTotalHitsUpTo(3);
            TopDocsCollectorManagerFactory topDocsContext = TopDocsCollectorManagerFactory.createTopDocsCollectorFactory(context, false);
            assertEquals(topDocsContext.collector().scoreMode(), org.apache.lucene.search.ScoreMode.COMPLETE);
            QueryPhase.executeQuery(context);
            assertEquals(5, context.queryResult().topDocs().topDocs.totalHits.value);
            assertEquals(context.queryResult().topDocs().topDocs.totalHits.relation, TotalHits.Relation.EQUAL_TO);
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(3));
        }
        {
            TestSearchContext context = createContext(newContextSearcher(reader), q);
            context.setSize(3);
            context.trackTotalHitsUpTo(3);
            context.sort(
                new SortAndFormats(new Sort(new SortField("other", SortField.Type.INT)), new DocValueFormat[] { DocValueFormat.RAW })
            );
            TopDocsCollectorManagerFactory topDocsContext = TopDocsCollectorManagerFactory.createTopDocsCollectorFactory(context, false);
            assertEquals(topDocsContext.collector().scoreMode(), org.apache.lucene.search.ScoreMode.TOP_DOCS);
            QueryPhase.executeQuery(context);
            assertEquals(5, context.queryResult().topDocs().topDocs.totalHits.value);
            assertThat(context.queryResult().topDocs().topDocs.scoreDocs.length, equalTo(3));
            assertEquals(context.queryResult().topDocs().topDocs.totalHits.relation, TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO);
        }
    }

    public void testNumericSortOptimization() throws Exception {
        final String fieldNameLong = "long-field";
        final String fieldNameDate = "date-field";
        MappedFieldType fieldTypeLong = new NumberFieldMapper.NumberFieldType(fieldNameLong, NumberFieldMapper.NumberType.LONG);
        MappedFieldType fieldTypeDate = new DateFieldMapper.DateFieldType(fieldNameDate);
        SearchExecutionContext searchExecutionContext = mock(SearchExecutionContext.class);
        when(searchExecutionContext.getFieldType(fieldNameLong)).thenReturn(fieldTypeLong);
        when(searchExecutionContext.getFieldType(fieldNameDate)).thenReturn(fieldTypeDate);
        // enough docs to have a tree with several leaf nodes
        final int numDocs = atLeast(3500 * 2);
        IndexWriter writer = new IndexWriter(dir, new IndexWriterConfig(null));
        long startLongValue = randomLongBetween(-10000000L, 10000000L);
        long longValue = startLongValue;
        long dateValue = randomLongBetween(0, 3000000000000L);

        for (int i = 1; i <= numDocs; ++i) {
            Document doc = new Document();
            doc.add(new LongPoint(fieldNameLong, longValue));
            doc.add(new NumericDocValuesField(fieldNameLong, longValue));
            doc.add(new LongPoint(fieldNameDate, dateValue));
            doc.add(new NumericDocValuesField(fieldNameDate, dateValue));
            writer.addDocument(doc);
            longValue++;
            dateValue++;
            if (i % 3500 == 0) writer.flush();
        }
        writer.close();
        reader = DirectoryReader.open(dir);

        final SortField sortFieldLong = new SortField(fieldNameLong, SortField.Type.LONG);
        final SortField sortFieldDate = new SortField(fieldNameDate, SortField.Type.LONG);
        sortFieldLong.setMissingValue(Long.MAX_VALUE);
        sortFieldDate.setMissingValue(Long.MAX_VALUE);
        final Sort sortLong = new Sort(sortFieldLong);
        final Sort sortDate = new Sort(sortFieldDate);
        final Sort sortLongDate = new Sort(sortFieldLong, sortFieldDate);
        final Sort sortDateLong = new Sort(sortFieldDate, sortFieldLong);
        final DocValueFormat dvFormatDate = fieldTypeDate.docValueFormat(null, null);
        final SortAndFormats formatsLong = new SortAndFormats(sortLong, new DocValueFormat[] { DocValueFormat.RAW });
        final SortAndFormats formatsDate = new SortAndFormats(sortDate, new DocValueFormat[] { dvFormatDate });
        final SortAndFormats formatsLongDate = new SortAndFormats(sortLongDate, new DocValueFormat[] { DocValueFormat.RAW, dvFormatDate });
        final SortAndFormats formatsDateLong = new SortAndFormats(sortDateLong, new DocValueFormat[] { dvFormatDate, DocValueFormat.RAW });

        Query q = LongPoint.newRangeQuery(fieldNameLong, startLongValue, startLongValue + numDocs);

        // 1. Test sort optimization on long field
        {
            TestSearchContext searchContext = createContext(newContextSearcher(reader), q);
            searchContext.sort(formatsLong);
            searchContext.trackTotalHitsUpTo(10);
            searchContext.setSize(10);
            QueryPhase.addCollectorsAndSearch(searchContext);
            assertTrue(searchContext.sort().sort.getSort()[0].getOptimizeSortWithPoints());
            assertSortResults(searchContext.queryResult().topDocs().topDocs, numDocs, false);
        }

        // 2. Test sort optimization on long field with after
        {
            TestSearchContext searchContext = createContext(newContextSearcher(reader), q);
            int afterDoc = (int) randomLongBetween(0, 30);
            long afterValue = startLongValue + afterDoc;
            FieldDoc after = new FieldDoc(afterDoc, Float.NaN, new Long[] { afterValue });
            searchContext.searchAfter(after);
            searchContext.sort(formatsLong);
            searchContext.trackTotalHitsUpTo(10);
            searchContext.setSize(10);
            QueryPhase.addCollectorsAndSearch(searchContext);
            assertTrue(searchContext.sort().sort.getSort()[0].getOptimizeSortWithPoints());
            final TopDocs topDocs = searchContext.queryResult().topDocs().topDocs;
            long firstResult = (long) ((FieldDoc) topDocs.scoreDocs[0]).fields[0];
            assertThat(firstResult, greaterThan(afterValue));
            assertSortResults(topDocs, numDocs, false);
        }

        // 3. Test sort optimization on long field + date field
        {
            TestSearchContext searchContext = createContext(newContextSearcher(reader), q);
            searchContext.sort(formatsLongDate);
            searchContext.trackTotalHitsUpTo(10);
            searchContext.setSize(10);
            QueryPhase.addCollectorsAndSearch(searchContext);
            assertTrue(searchContext.sort().sort.getSort()[0].getOptimizeSortWithPoints());
            assertSortResults(searchContext.queryResult().topDocs().topDocs, numDocs, true);
        }

        // 4. Test sort optimization on date field
        {
            TestSearchContext searchContext = createContext(newContextSearcher(reader), q);
            searchContext.sort(formatsDate);
            searchContext.trackTotalHitsUpTo(10);
            searchContext.setSize(10);
            QueryPhase.addCollectorsAndSearch(searchContext);
            assertTrue(searchContext.sort().sort.getSort()[0].getOptimizeSortWithPoints());
            assertSortResults(searchContext.queryResult().topDocs().topDocs, numDocs, false);
        }

        // 5. Test sort optimization on date field + long field
        {
            TestSearchContext searchContext = createContext(newContextSearcher(reader), q);
            searchContext.sort(formatsDateLong);
            searchContext.trackTotalHitsUpTo(10);
            searchContext.setSize(10);
            QueryPhase.addCollectorsAndSearch(searchContext);
            assertTrue(searchContext.sort().sort.getSort()[0].getOptimizeSortWithPoints());
            assertSortResults(searchContext.queryResult().topDocs().topDocs, numDocs, true);
        }

        // 6. Test sort optimization on when from > 0 and size = 0
        {
            TestSearchContext searchContext = createContext(newContextSearcher(reader), q);
            searchContext.sort(formatsLong);
            searchContext.trackTotalHitsUpTo(10);
            searchContext.from(5);
            searchContext.setSize(0);
            QueryPhase.addCollectorsAndSearch(searchContext);
            assertTrue(searchContext.sort().sort.getSort()[0].getOptimizeSortWithPoints());
            assertThat(searchContext.queryResult().topDocs().topDocs.scoreDocs, arrayWithSize(0));
            assertThat(searchContext.queryResult().topDocs().topDocs.totalHits.value, equalTo((long) numDocs));
            assertThat(searchContext.queryResult().topDocs().topDocs.totalHits.relation, equalTo(TotalHits.Relation.EQUAL_TO));
        }

        // 7. Test that sort optimization doesn't break a case where from = 0 and size= 0
        {
            TestSearchContext searchContext = createContext(newContextSearcher(reader), q);
            searchContext.sort(formatsLong);
            searchContext.setSize(0);
            QueryPhase.addCollectorsAndSearch(searchContext);
        }
    }

    public void testMaxScoreQueryVisitor() {
        BitSetProducer producer = context -> new FixedBitSet(1);
        Query query = new ESToParentBlockJoinQuery(new MatchAllDocsQuery(), producer, ScoreMode.Avg, "nested");
        assertTrue(hasInfMaxScore(query));

        query = new ESToParentBlockJoinQuery(new MatchAllDocsQuery(), producer, ScoreMode.None, "nested");
        assertFalse(hasInfMaxScore(query));

        for (Occur occur : Occur.values()) {
            query = new BooleanQuery.Builder().add(
                new ESToParentBlockJoinQuery(new MatchAllDocsQuery(), producer, ScoreMode.Avg, "nested"),
                occur
            ).build();
            if (occur == Occur.MUST) {
                assertTrue(hasInfMaxScore(query));
            } else {
                assertFalse(hasInfMaxScore(query));
            }

            query = new BooleanQuery.Builder().add(
                new BooleanQuery.Builder().add(
                    new ESToParentBlockJoinQuery(new MatchAllDocsQuery(), producer, ScoreMode.Avg, "nested"),
                    occur
                ).build(),
                occur
            ).build();
            if (occur == Occur.MUST) {
                assertTrue(hasInfMaxScore(query));
            } else {
                assertFalse(hasInfMaxScore(query));
            }

            query = new BooleanQuery.Builder().add(
                new BooleanQuery.Builder().add(
                    new ESToParentBlockJoinQuery(new MatchAllDocsQuery(), producer, ScoreMode.Avg, "nested"),
                    occur
                ).build(),
                Occur.FILTER
            ).build();
            assertFalse(hasInfMaxScore(query));

            query = new BooleanQuery.Builder().add(
                new BooleanQuery.Builder().add(new SpanTermQuery(new Term("field", "foo")), occur)
                    .add(new ESToParentBlockJoinQuery(new MatchAllDocsQuery(), producer, ScoreMode.Avg, "nested"), occur)
                    .build(),
                occur
            ).build();
            if (occur == Occur.MUST) {
                assertTrue(hasInfMaxScore(query));
            } else {
                assertFalse(hasInfMaxScore(query));
            }
        }
    }

    // assert score docs are in order and their number is as expected
    private static void assertSortResults(TopDocs topDocs, long totalNumDocs, boolean isDoubleSort) {
        assertEquals(TotalHits.Relation.GREATER_THAN_OR_EQUAL_TO, topDocs.totalHits.relation);
        assertThat(topDocs.totalHits.value, lessThan(totalNumDocs)); // we collected less docs than total number
        long cur1, cur2;
        long prev1 = Long.MIN_VALUE;
        long prev2 = Long.MIN_VALUE;
        for (ScoreDoc scoreDoc : topDocs.scoreDocs) {
            cur1 = (long) ((FieldDoc) scoreDoc).fields[0];
            assertThat(cur1, greaterThan(prev1)); // test that docs are properly sorted on the first sort
            if (isDoubleSort) {
                cur2 = (long) ((FieldDoc) scoreDoc).fields[1];
                if (cur1 == prev1) {
                    assertThat(cur2, greaterThan(prev2)); // test that docs are properly sorted on the secondary sort
                }
                prev2 = cur2;
            }
            prev1 = cur1;
        }
    }

    public void testMinScore() throws Exception {
        IndexWriterConfig iwc = newIndexWriterConfig();
        RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);
        for (int i = 0; i < 10; i++) {
            Document doc = new Document();
            doc.add(new StringField("foo", "bar", Store.NO));
            doc.add(new StringField("filter", "f1", Store.NO));
            w.addDocument(doc);
        }
        w.close();
        reader = DirectoryReader.open(dir);

        BooleanQuery booleanQuery = new BooleanQuery.Builder().add(new TermQuery(new Term("foo", "bar")), Occur.MUST)
            .add(new TermQuery(new Term("filter", "f1")), Occur.SHOULD)
            .build();
        TestSearchContext context = createContext(newContextSearcher(reader), booleanQuery);
        context.minimumScore(0.01f);
        context.setSize(1);
        context.trackTotalHitsUpTo(5);

        QueryPhase.addCollectorsAndSearch(context);
        assertEquals(10, context.queryResult().topDocs().topDocs.totalHits.value);
    }

    public void testCancellationDuringRewrite() throws IOException {
        RandomIndexWriter w = new RandomIndexWriter(random(), dir, newIndexWriterConfig());
        for (int i = 0; i < 10; i++) {
            Document doc = new Document();
            doc.add(new StringField("foo", "a".repeat(i), Store.NO));
            w.addDocument(doc);
        }
        w.flush();
        w.close();

        reader = DirectoryReader.open(dir);
        PrefixQuery prefixQuery = new PrefixQuery(new Term("foo", "a"), MultiTermQuery.SCORING_BOOLEAN_REWRITE);
        TestSearchContext context = createContext(newContextSearcher(reader), prefixQuery);
        SearchShardTask task = new SearchShardTask(randomLong(), "transport", "", "", TaskId.EMPTY_TASK_ID, Collections.emptyMap());
        TaskCancelHelper.cancel(task, "simulated");
        context.setTask(task);
        context.searcher().addQueryCancellation(task::ensureNotCancelled);
        expectThrows(TaskCancelledException.class, context::rewrittenQuery);
    }

    public void testRank() throws IOException {
        IndexWriterConfig iwc = newIndexWriterConfig();
        RandomIndexWriter w = new RandomIndexWriter(random(), dir, iwc);
        for (int i = 0; i < 10; i++) {
            Document doc = new Document();
            doc.add(new KeywordField("field0", "term", Store.NO));
            doc.add(new KeywordField("field1", "term" + i, Store.NO));
            w.addDocument(doc);
        }
        w.close();
        reader = DirectoryReader.open(dir);

        final List<Query> executed = new ArrayList<>();
        ContextIndexSearcher searcher = new ContextIndexSearcher(
            reader,
            IndexSearcher.getDefaultSimilarity(),
            IndexSearcher.getDefaultQueryCache(),
            IndexSearcher.getDefaultQueryCachingPolicy(),
            true
        ) {
            @Override
            public <C extends Collector, T> T search(Query query, CollectorManager<C, T> collectorManager) throws IOException {
                executed.add(query);
                return super.search(query, collectorManager);
            }
        };

        SearchContext context = new TestSearchContext(null, indexShard, searcher) {
            @Override
            public Query buildFilteredQuery(Query query) {
                return query;
            }

            @Override
            public ReaderContext readerContext() {
                return new ReaderContext(new ShardSearchContextId("test", 1L), null, indexShard, null, 0L, false);
            }
        };

        List<Query> queries = List.of(new TermQuery(new Term("field0", "term")), new TermQuery(new Term("field1", "term0")));
        context.parsedQuery(
            new ParsedQuery(new BooleanQuery.Builder().add(queries.get(0), Occur.SHOULD).add(queries.get(1), Occur.SHOULD).build())
        );
        context.rankShardContext(new RankShardContext(queries, 0, 100) {
            @Override
            public RankShardResult combine(List<TopDocs> rankResults) {
                return null;
            }
        });

        context.trackTotalHitsUpTo(SearchContext.TRACK_TOTAL_HITS_DISABLED);
        context.aggregations(null);
        QueryPhase.executeRank(context);
        assertEquals(queries, executed);

        executed.clear();
        context.trackTotalHitsUpTo(100);
        context.aggregations(null);
        QueryPhase.executeRank(context);
        assertEquals(context.rewrittenQuery(), executed.get(0));
        assertEquals(queries, executed.subList(1, executed.size()));

        executed.clear();
        context.trackTotalHitsUpTo(SearchContext.TRACK_TOTAL_HITS_DISABLED);
        context.aggregations(new SearchContextAggregations(AggregatorFactories.EMPTY));
        QueryPhase.executeRank(context);
        assertEquals(context.rewrittenQuery(), executed.get(0));
        assertEquals(queries, executed.subList(1, executed.size()));
    }

    private static final QueryCachingPolicy NEVER_CACHE_POLICY = new QueryCachingPolicy() {
        @Override
        public void onUse(Query query) {}

        @Override
        public boolean shouldCache(Query query) {
            return false;
        }
    };

    private static ContextIndexSearcher newContextSearcher(IndexReader reader) throws IOException {
        return new ContextIndexSearcher(
            reader,
            IndexSearcher.getDefaultSimilarity(),
            IndexSearcher.getDefaultQueryCache(),
            NEVER_CACHE_POLICY,
            true
        );
    }

    private static ContextIndexSearcher noCollectionContextSearcher(IndexReader reader) throws IOException {
        return earlyTerminationContextSearcher(reader, 0);
    }

    private static ContextIndexSearcher earlyTerminationContextSearcher(IndexReader reader, int size) throws IOException {
        return new ContextIndexSearcher(
            reader,
            IndexSearcher.getDefaultSimilarity(),
            IndexSearcher.getDefaultQueryCache(),
            NEVER_CACHE_POLICY,
            true
        ) {

            @Override
            public void search(List<LeafReaderContext> leaves, Weight weight, Collector collector) throws IOException {
                final Collector in = new FilterCollector(collector) {
                    @Override
                    public LeafCollector getLeafCollector(LeafReaderContext context) throws IOException {
                        final LeafCollector in = super.getLeafCollector(context);
                        return new FilterLeafCollector(in) {
                            int collected;

                            @Override
                            public void collect(int doc) throws IOException {
                                assert collected <= size : "should not collect more than " + size + " doc per segment, got " + collected;
                                ++collected;
                                super.collect(doc);
                            }
                        };
                    }
                };
                super.search(leaves, weight, in);
            }
        };
    }
}
