package org.apache.lucene.wordnet;

import org.apache.lucene.store.*;
import org.apache.lucene.search.*;
import org.apache.lucene.index.*;
import org.apache.lucene.document.*;
import org.apache.lucene.analysis.*;
import java.io.*;
import java.util.*;


/**
 * Test program to look up synonyms.
 */
public class SynLookup {

	public static void main(String[] args) throws IOException {
		if (args.length != 2) {
			System.out.println(
							   "java org.apache.lucene.wordnet.SynLookup <index path> <word>");
		}

		FSDirectory directory = FSDirectory.getDirectory(args[0], false);
		IndexSearcher searcher = new IndexSearcher(directory);

		String word = args[1];
		Hits hits = searcher.search(
									new TermQuery(new Term(Syns2Index.F_WORD, word)));

		if (hits.length() == 0) {
			System.out.println("No synonyms found for " + word);
		} else {
			System.out.println("Synonyms found for \"" + word + "\":");
		}

		for (int i = 0; i < hits.length(); i++) {
			Document doc = hits.doc(i);

			String[] values = doc.getValues(Syns2Index.F_SYN);

			for (int j = 0; j < values.length; j++) {
				System.out.println(values[j]);
			}
		}

		searcher.close();
		directory.close();
	}


	/**
	 * Perform synonym expansion on a query.
	 *
	 * @param query
	 * @param syns
	 * @param a
	 * @param field
	 * @param boost
	 */ 
	public static Query expand( String query,
								Searcher syns,
								Analyzer a,
								String field,
								float boost)
		throws IOException
	{
		Set already = new HashSet(); // avoid dups		
		List top = new LinkedList(); // needs to be separately listed..

		// [1] Parse query into separate words so that when we expand we can avoid dups
		TokenStream ts = a.tokenStream( field, new StringReader( query));
		org.apache.lucene.analysis.Token t;
		while ( (t = ts.next()) != null)
		{
			String word = t.termText();
			if ( already.add( word))
				top.add( word);
		}
		BooleanQuery tmp = new BooleanQuery();
		
		// [2] form query
		Iterator it = top.iterator();
		while ( it.hasNext())
		{
			// [2a] add to level words in
			String word = (String) it.next();
			TermQuery tq = new TermQuery( new Term( field, word));
			tmp.add( tq, BooleanClause.Occur.SHOULD);

			// [2b] add in unique synonums
			Hits hits = syns.search( new TermQuery( new Term(Syns2Index.F_WORD, word)));
			for (int i = 0; i < hits.length(); i++)
			{
				Document doc = hits.doc(i);
				String[] values = doc.getValues( Syns2Index.F_SYN);
				for ( int j = 0; j < values.length; j++)
				{
					String syn = values[ j];
					if ( already.add( syn))
					{
						tq = new TermQuery( new Term( field, syn));
						if ( boost > 0) // else keep normal 1.0
							tq.setBoost( boost);
						tmp.add( tq, BooleanClause.Occur.SHOULD); 
					}
				}
			}
		}


		return tmp;
	}
								
}