/*
 * 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.
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package org.apache.lucene.search.grouping;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.NumericDocValuesField;
import org.apache.lucene.document.StringField;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.NoMergePolicy;
import org.apache.lucene.index.Term;
import org.apache.lucene.queries.function.FunctionScoreQuery;
import org.apache.lucene.search.DoubleValuesSource;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.store.ByteBuffersDirectory;
import org.apache.lucene.store.Directory;
import org.apache.lucene.tests.util.LuceneTestCase;

public class TestBlockGroupingMaxScoreSlicing extends LuceneTestCase {

  public void testMaxScoreDoesNotDependOnSlicing() throws Exception {
    try (Directory dir = new ByteBuffersDirectory()) {
      IndexWriterConfig iwc = new IndexWriterConfig().setMergePolicy(NoMergePolicy.INSTANCE);
      try (IndexWriter w = new IndexWriter(dir, iwc)) {
        for (int v : new int[] {1, 3, 4, 5, 6, 2}) {
          Document doc = new Document();
          doc.add(new NumericDocValuesField("v", v));
          doc.add(new StringField("groupEnd", "x", Field.Store.NO));
          w.addDocument(doc);
          w.flush();
        }
      }
      try (DirectoryReader reader = DirectoryReader.open(dir)) {
        GroupingSearch gs = new GroupingSearch(new TermQuery(new Term("groupEnd", "x")));
        gs.setGroupSort(new Sort(new SortField("v", SortField.Type.INT)));
        DoubleValuesSource score = DoubleValuesSource.fromIntField("v");
        Query query = new FunctionScoreQuery(MatchAllDocsQuery.INSTANCE, score);
        float sequential = gs.search(new IndexSearcher(reader), query, 0, 1).maxScore;
        float sliced = gs.search(new IndexSearcher(reader, Runnable::run), query, 0, 1).maxScore;
        // expected 1.0 (top group v=1) with 6 segments in 2 slices too; actual 2.0 (group v=2)
        assertEquals("TopGroups.maxScore, 1 slice vs 2 slices", sequential, sliced, 0f);
      }
    }
  }
}