/*
 * 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.common.lucene.search.morelikethis;

import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
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.search.IndexSearcher;
import org.apache.lucene.store.ByteBuffersDirectory;
import org.apache.lucene.store.Directory;
import org.elasticsearch.common.lucene.Lucene;
import org.elasticsearch.common.lucene.search.MoreLikeThisQuery;
import org.elasticsearch.test.ESTestCase;

import static org.hamcrest.Matchers.containsString;
import static org.hamcrest.Matchers.equalTo;

public class MoreLikeThisQueryTests extends ESTestCase {
    public void testSimple() throws Exception {
        Directory dir = new ByteBuffersDirectory();
        IndexWriter indexWriter = new IndexWriter(dir, new IndexWriterConfig(Lucene.STANDARD_ANALYZER));
        indexWriter.commit();

        Document document = new Document();
        document.add(new TextField("_id", "1", Field.Store.YES));
        document.add(new TextField("text", "lucene", Field.Store.YES));
        indexWriter.addDocument(document);

        document = new Document();
        document.add(new TextField("_id", "2", Field.Store.YES));
        document.add(new TextField("text", "lucene release", Field.Store.YES));
        indexWriter.addDocument(document);

        IndexReader reader = DirectoryReader.open(indexWriter);
        IndexSearcher searcher = new IndexSearcher(reader);

        MoreLikeThisQuery mltQuery = new MoreLikeThisQuery("lucene", new String[]{"text"}, Lucene.STANDARD_ANALYZER);
        mltQuery.setLikeText("lucene");
        mltQuery.setMinTermFrequency(1);
        mltQuery.setMinDocFreq(1);
        long count = searcher.count(mltQuery);
        assertThat(count, equalTo(2L));

        reader.close();
        indexWriter.close();
    }

    public void testValidateMaxQueryTerms() {
        IllegalArgumentException e1 = expectThrows(IllegalArgumentException.class,
            () ->  new MoreLikeThisQuery("lucene", new String[]{"text"}, Lucene.STANDARD_ANALYZER).setMaxQueryTerms(0));
        assertThat(e1.getMessage(), containsString("requires 'maxQueryTerms' to be greater than 0"));

        IllegalArgumentException e2 = expectThrows(IllegalArgumentException.class,
            () -> new MoreLikeThisQuery("lucene", new String[]{"text"}, Lucene.STANDARD_ANALYZER).setMaxQueryTerms(-3));
        assertThat(e2.getMessage(), containsString("requires 'maxQueryTerms' to be greater than 0"));
    }

}
