/*
 *  eXist Open Source Native XML Database: Extension module
 *  Copyright (C) 2008 Josef Willenborg
 *  jwillenborg@mpiwg-berlin.mpg.de
 *  http://www.mpiwg-berlin.mpg.de
 *  
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *  
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 *  
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *  
 *  $Id: TextModule.java $
 */
package org.exist.xquery.modules.mpdltext;

import java.util.ArrayList;

import org.exist.dom.QName;
import org.exist.memtree.DocumentImpl;
import org.exist.memtree.MemTreeBuilder;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;

import de.mpg.mpiwg.berlin.mpdl.exception.ApplicationException;
import de.mpg.mpiwg.berlin.mpdl.lt.morph.app.Form;
import de.mpg.mpiwg.berlin.mpdl.lt.morph.app.Lemma;
import de.mpg.mpiwg.berlin.mpdl.lt.morph.app.MorphologyCache;

/**
 * @author Josef Willenborg (jwillenborg@mpiwg-berlin.mpg.de)
 */
public class GetLemmasByLuceneQuery extends BasicFunction {

	public final static FunctionSignature signature =
		new FunctionSignature(
			new QName("get-lemmas-by-lucene-query", MPDLTextModule.NAMESPACE_URI, MPDLTextModule.PREFIX),
			"A function which delivers the lemma of a given lucene query and language " +
			"by the MPDL language technology",
			new SequenceType[] { new SequenceType(Type.STRING, Cardinality.ZERO_OR_MORE), 
			                     new SequenceType(Type.STRING, Cardinality.ZERO_OR_MORE) },
			new SequenceType(Type.NODE, Cardinality.EXACTLY_ONE));

	public GetLemmasByLuceneQuery(XQueryContext context) {
		super(context, signature);
	}

	public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {
	  Sequence langSeq = args[0];
    Sequence luceneQuerySeq = args[1];
    String language = "";
    String luceneQueryStr = "";
		if (langSeq.isEmpty() || luceneQuerySeq.isEmpty())
			return Sequence.EMPTY_SEQUENCE;
		language = langSeq.getStringValue();
		luceneQueryStr = luceneQuerySeq.getStringValue();
		ArrayList<Lemma> lemmas = null;
		try { 
	    MorphologyCache morphologyCache = MorphologyCache.getInstance();
	    lemmas = morphologyCache.getLemmasByLuceneQuery(language, luceneQueryStr, true);
    } catch (ApplicationException e) {
      throw new XPathException(e);
    }
    DocumentImpl doc = null;
    if (lemmas != null) {
      MemTreeBuilder builder = context.getDocumentBuilder();
      builder.startElement("", "lemmas", "lemmas", null);
      for (int i=0; i<lemmas.size(); i++) {
        Lemma lemma = lemmas.get(i);
        builder.startElement("", "lemma", "lemma", null);
        builder.startElement("", "provider", "provider", null);
        builder.characters(lemma.getProvider());
        builder.endElement();
        builder.startElement("", "language", "language", null);
        builder.characters(lemma.getLanguage());
        builder.endElement();
        builder.startElement("", "lemma-name", "lemma-name", null);
        builder.characters(lemma.getLemmaName());
        builder.endElement();
        ArrayList<Form> forms = lemma.getFormsList();
        builder.startElement("", "forms-size", "forms-size", null);
        builder.characters(String.valueOf(forms.size()));
        builder.endElement();
        builder.startElement("", "forms", "forms", null);
        for (int j=0; j<forms.size(); j++) {
          Form form = forms.get(j);
          builder.startElement("", "form", "form", null);
          builder.startElement("", "provider", "provider", null);
          builder.characters(form.getProvider());
          builder.endElement();
          builder.startElement("", "language", "language", null);
          builder.characters(form.getLanguage());
          builder.endElement();
          builder.startElement("", "form-name", "form-name", null);
          builder.characters(form.getFormName());
          builder.endElement();
          builder.startElement("", "lemma-name", "lemma-name", null);
          builder.characters(lemma.getLemmaName());
          builder.endElement();
          builder.endElement();
        }
        builder.endElement();
        builder.endElement();
      }
      builder.endElement();
      doc = ((DocumentImpl)builder.getDocument());
    } else {
      return Sequence.EMPTY_SEQUENCE;
    }
		return doc;
	}
}