/* Copyright: 
 * 		transaxtions llc
 *		Pleasanton, CA 94588, USA
 *
 * License: 
 * 		Please see License Agreement. Contact transaxtions llc for more info.
 * 
 * Author: 
 * 		Nagendra Nagarajayya
 * 
 * Ver: 
 * 		1.0
 * 
 * Description:
 * 		Needs 3-4 arguments. 
 * 		First argument, specifies the index, 
 * 		second the field, 
 * 		third, the search terms,
 * 		fourth optional, field name to output.
 *   
 * Comments: 
 * 		2011/08/18 - First release 
 */

import java.io.File;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.queryParser.QueryParser;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.TopScoreDocCollector;
import org.apache.lucene.store.FSDirectory;
import org.apache.lucene.util.Version;

import org.tgels.search.rankingalgorithm.*;
/**
 * LuceneCollectorExample code showing RankingAlgorithm usage. Very easy to uses, similar to
 * Lucene API. Needs access to a Lucene index to work.
 * <pre>
 * {@code
 * args[0] is a lucene index path
 * args[1] is the field to search on
 * args[2] are the search terms
 * args[3] is the field to show in the results
 * 
 * Example: 
 * 	java LuceneCollectorExample "/lucene/index" contents "ranking algorithm" text
 * }
 * </pre> 
 * 
 * @author Nagendra Nagarajayya
 * 
 * @see RankingQuery
 * @see RankingHits
 * @see RankingScore
 * 
 */
public class LuceneCollectorExample {	
	static public void main(String args[]) { 
		String index = args[0]; // lucene index path
		String field = args[1];	// field to search 	
		String searchterms = args[2]; // search terms
		String title = null;	// field to output, default title
		System.out.println("args len=" + args.length);
		if (args.length > 3) {
			title = args[3];
		}
		
		if (title == null) {
			title = "title";
		}
		System.out.println("field contents=" + field + " title=" + title);
		try {
			IndexReader reader = IndexReader.open(FSDirectory.open(new File(index))); 
		 	RankingQuery rq = new RankingQuery();			
			 StandardAnalyzer analyzer = new StandardAnalyzer(Version.LUCENE_30);
			 QueryParser parser = new QueryParser(Version.LUCENE_30, field, analyzer);
			 Query query = parser.parse(searchterms);
			 TopScoreDocCollector tdc = TopScoreDocCollector.create(1000, true);
			 rq.search(query, null, reader, tdc); //is = Lucene IndexSearcher object
			 int hits = tdc.getTotalHits();
			 ScoreDoc sda[] = null;
			 if (hits > 0) {
				 sda = tdc.topDocs().scoreDocs;
			 }
			 System.out.println("num hits=" + hits + "--no docs=" + reader.maxDoc()); 
			 for (int i=0; i<hits && i<10; i++) {
				 ScoreDoc sd = sda[i];
				 System.out.println("i=" + i + "--" + sd.score + "--docid=" + sd.doc + "--doc=" + reader.document(sd.doc).get(title) );
			 }
			 reader.close();
		} catch(Throwable t) {
			t.printStackTrace();
		}
	}
}