/*
 * 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
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package org.apache.lucene.search.suggest.document;

import org.apache.lucene.analysis.Analyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.index.Term;
import org.apache.lucene.store.ByteBuffersDirectory;
import org.apache.lucene.store.Directory;
import org.apache.lucene.tests.analysis.MockAnalyzer;
import org.apache.lucene.tests.util.LuceneTestCase;
import org.apache.lucene.tests.util.TestUtil;

public class TestContextQueryManyContextsTopN extends LuceneTestCase {

  public void testAllContextsQueryOnOneMillionContexts() throws Exception {
    Analyzer analyzer = new MockAnalyzer(random());
    IndexWriterConfig iwc = new IndexWriterConfig(analyzer).setRAMBufferSizeMB(256);
    iwc.setCodec(TestUtil.alwaysPostingsFormat(new Completion104PostingsFormat()));
    try (Directory dir = new ByteBuffersDirectory();
        IndexWriter w = new IndexWriter(dir, iwc)) {
      for (int i = 0; i < 1_000_000; i++) {
        Document doc = new Document();
        doc.add(new ContextSuggestField("suggest", "lucene", 1, "ctx" + i));
        w.addDocument(doc);
      }
      w.forceMerge(1);
      try (DirectoryReader reader = DirectoryReader.open(w)) {
        SuggestIndexSearcher searcher = new SuggestIndexSearcher(reader);
        ContextQuery query =
            new ContextQuery(new PrefixCompletionQuery(analyzer, new Term("suggest", "luc")));
        // expected 2148 hits, actual 0: topN = 2148 * 10^6 prefix paths wraps negative in int
        assertEquals(2148, searcher.suggest(query, 2148, false).scoreLookupDocs().length);
      }
    }
    analyzer.close();
  }
}