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 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch 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.elasticsearch.search.aggregations.bucket.significant;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.SortedNumericDocValuesField;
import org.apache.lucene.document.StoredField;
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.RandomIndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.store.Directory;
import org.apache.lucene.util.BytesRef;
import org.elasticsearch.index.analysis.AnalyzerScope;
import org.elasticsearch.index.analysis.NamedAnalyzer;
import org.elasticsearch.index.mapper.MappedFieldType;
import org.elasticsearch.index.mapper.NumberFieldMapper;
import org.elasticsearch.index.mapper.SourceFieldMapper;
import org.elasticsearch.index.mapper.TextFieldMapper.TextFieldType;
import org.elasticsearch.index.query.QueryShardContext;
import org.elasticsearch.index.query.QueryShardException;
import org.elasticsearch.search.aggregations.AggregatorTestCase;
import org.elasticsearch.search.aggregations.bucket.sampler.Sampler;
import org.elasticsearch.search.aggregations.bucket.sampler.SamplerAggregationBuilder;
import org.elasticsearch.search.aggregations.bucket.significant.SignificantTerms;
import org.elasticsearch.search.aggregations.bucket.significant.SignificantTerms.Bucket;
import org.elasticsearch.search.aggregations.bucket.significant.SignificantTextAggregationBuilder;

import java.io.IOException;
import java.util.Arrays;

public class SignificantTextAggregatorTests extends AggregatorTestCase {
  
    
    /**
     * Uses the significant text aggregation to find the keywords in text fields
     */
    public void testSignificance() throws IOException {
        TextFieldType textFieldType = new TextFieldType();
        textFieldType.setName("text");
        textFieldType.setIndexAnalyzer(new NamedAnalyzer("my_analyzer", AnalyzerScope.GLOBAL, new StandardAnalyzer()));

        IndexWriterConfig indexWriterConfig = newIndexWriterConfig();
        try (Directory dir = newDirectory(); IndexWriter w = new IndexWriter(dir, indexWriterConfig)) {
            for (int i = 0; i < 10; i++) {
                Document doc = new Document();
                StringBuilder text = new StringBuilder("common ");
                if (i % 2 == 0) {
                    text.append("odd ");
                } else {                    
                    text.append("even separator" + i + " duplicate duplicate duplicate duplicate duplicate duplicate ");
                }

                doc.add(new Field("text", text.toString(), textFieldType));
                String json ="{ \"text\" : \"" + text.toString() + "\","+
                             " \"json_only_field\" : \"" + text.toString() + "\"" +
                            " }";
                doc.add(new StoredField("_source", new BytesRef(json)));
                w.addDocument(doc);
            }

            SignificantTextAggregationBuilder sigAgg = new SignificantTextAggregationBuilder("sig_text", "text").filterDuplicateText(true);
            if(randomBoolean()){
                sigAgg.sourceFieldNames(Arrays.asList(new String [] {"json_only_field"}));
            }
            SamplerAggregationBuilder aggBuilder = new SamplerAggregationBuilder("sampler")
                    .subAggregation(sigAgg);
            
            try (IndexReader reader = DirectoryReader.open(w)) {
                IndexSearcher searcher = new IndexSearcher(reader);
                                
                // Search "odd" which should have no duplication
                Sampler sampler = searchAndReduce(searcher, new TermQuery(new Term("text", "odd")), aggBuilder, textFieldType);
                SignificantTerms terms = sampler.getAggregations().get("sig_text");
                
                assertNull(terms.getBucketByKey("even"));
                assertNull(terms.getBucketByKey("duplicate"));                
                assertNull(terms.getBucketByKey("common"));                
                assertNotNull(terms.getBucketByKey("odd"));

                // Search "even" which will have duplication
                sampler = searchAndReduce(searcher, new TermQuery(new Term("text", "even")), aggBuilder, textFieldType);
                terms = sampler.getAggregations().get("sig_text");
                
                assertNull(terms.getBucketByKey("odd"));
                assertNull(terms.getBucketByKey("duplicate"));                
                assertNull(terms.getBucketByKey("common"));    
                assertNull(terms.getBucketByKey("separator2"));
                assertNull(terms.getBucketByKey("separator4"));
                assertNull(terms.getBucketByKey("separator6"));

                assertNotNull(terms.getBucketByKey("even"));
            
            }
        }
    }
    
    /**
     * Test documents with arrays of text
     */
    public void testSignificanceOnTextArrays() throws IOException {
        TextFieldType textFieldType = new TextFieldType();
        textFieldType.setName("text");
        textFieldType.setIndexAnalyzer(new NamedAnalyzer("my_analyzer", AnalyzerScope.GLOBAL, new StandardAnalyzer()));

        IndexWriterConfig indexWriterConfig = newIndexWriterConfig();
        try (Directory dir = newDirectory(); IndexWriter w = new IndexWriter(dir, indexWriterConfig)) {
            for (int i = 0; i < 10; i++) {
                Document doc = new Document();
                doc.add(new Field("text", "foo", textFieldType));
                String json ="{ \"text\" : [\"foo\",\"foo\"], \"title\" : [\"foo\", \"foo\"]}";
                doc.add(new StoredField("_source", new BytesRef(json)));
                w.addDocument(doc);
            }

            SignificantTextAggregationBuilder sigAgg = new SignificantTextAggregationBuilder("sig_text", "text");
            sigAgg.sourceFieldNames(Arrays.asList(new String [] {"title", "text"}));
            try (IndexReader reader = DirectoryReader.open(w)) {
                IndexSearcher searcher = new IndexSearcher(reader);                                
                searchAndReduce(searcher, new TermQuery(new Term("text", "foo")), sigAgg, textFieldType);
                // No significant results to be found in this test - only checking we don't end up
                // with the internal exception discovered in issue https://github.com/elastic/elasticsearch/issues/25029
            }
        }
    }
    
    
}