/*
 *  eXist Open Source Native XML Database
 *  Copyright (C) 2001-09 Wolfgang M. Meier
 *  wolfgang@exist-db.org
 *  http://exist.sourceforge.net
 *
 *  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.
 *
 *  $Id$
 */
package org.exist.xquery.functions.util;

import org.apache.log4j.Logger;
import org.exist.dom.QName;
import org.exist.memtree.DocumentBuilderReceiver;
import org.exist.memtree.InMemoryNodeSet;
import org.exist.memtree.MemTreeBuilder;
import org.exist.storage.serializers.EXistOutputKeys;
import org.exist.xquery.BasicFunction;
import org.exist.xquery.Cardinality;
import org.exist.xquery.FunctionSignature;
import org.exist.xquery.Option;
import org.exist.xquery.XPathException;
import org.exist.xquery.XQueryContext;
import org.exist.xquery.value.FunctionParameterSequenceType;
import org.exist.xquery.value.FunctionReturnSequenceType;
import org.exist.xquery.value.NodeValue;
import org.exist.xquery.value.Sequence;
import org.exist.xquery.value.SequenceIterator;
import org.exist.xquery.value.SequenceType;
import org.exist.xquery.value.Type;
import org.xml.sax.SAXException;

import java.util.Properties;

public class Expand extends BasicFunction {
	
	protected static final Logger logger = Logger.getLogger(Expand.class);

    public final static FunctionSignature signatures[] = {
        new FunctionSignature(
            new QName("expand", UtilModule.NAMESPACE_URI, UtilModule.PREFIX),
            "Creates an in-memory copy of the passed node set, using the specified " +
            "serialization options. By default, full-text match terms will be " +
            "tagged with <exist:match> and XIncludes will be expanded.",
            new SequenceType[]{
                new FunctionParameterSequenceType("node", Type.NODE, Cardinality.ZERO_OR_MORE, "The node(s) to create in-memory copies of.")
            },
            new FunctionReturnSequenceType(Type.NODE, Cardinality.ZERO_OR_MORE, "the results")),
        new FunctionSignature(
            new QName("expand", UtilModule.NAMESPACE_URI, UtilModule.PREFIX),
            "Creates an in-memory copy of the passed node set, using the specified " +
            "serialization options. By default, full-text match terms will be " +
            "tagged with <exist:match> and XIncludes will be expanded. Serialization " +
            "parameters can be set in the second argument, which accepts the same parameters " +
            "as the exist:serialize option.",
            new SequenceType[]{
                new FunctionParameterSequenceType("node", Type.NODE, Cardinality.ZERO_OR_MORE, "The node(s) to create in-memory copies of."),
                new FunctionParameterSequenceType("serialization-parameters", Type.STRING, Cardinality.EXACTLY_ONE, "The serialization parameters")
            },
            new FunctionReturnSequenceType(Type.NODE, Cardinality.ZERO_OR_MORE, "the results"))
    };

    public Expand(XQueryContext context, FunctionSignature signature) {
        super(context, signature);
    }

    public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathException {

    	if (args[0].isEmpty()) {
            return Sequence.EMPTY_SEQUENCE;
    	}

        // apply serialization options set on the XQuery context
        Properties serializeOptions = new Properties();
        serializeOptions.setProperty(EXistOutputKeys.EXPAND_XINCLUDES, "yes");
        serializeOptions.setProperty(EXistOutputKeys.HIGHLIGHT_MATCHES, "elements");
        if (getArgumentCount() == 2) {
            String serOpts = args[1].getStringValue();
            String[] contents = Option.tokenize(serOpts);
            for (int i = 0; i < contents.length; i++) {
                String[] pair = Option.parseKeyValuePair(contents[i]);
                if (pair == null)
                    throw new XPathException(this, "Found invalid serialization option: " + pair);
                logger.debug("Setting serialization property: " + pair[0] + " = " + pair[1]);
                serializeOptions.setProperty(pair[0], pair[1]);
            }
        } else
            context.checkOptions(serializeOptions);

        context.pushDocumentContext();
        try {
            InMemoryNodeSet result = new InMemoryNodeSet();
            MemTreeBuilder builder = context.getDocumentBuilder();
            DocumentBuilderReceiver receiver = new DocumentBuilderReceiver(builder, true);
            for (SequenceIterator i = args[0].iterate(); i.hasNext(); ) {
                int nodeNr = builder.getDocument().getLastNode();
                NodeValue next = (NodeValue) i.nextItem();
                next.toSAX(context.getBroker(), receiver, serializeOptions);
                result.add(builder.getDocument().getNode(nodeNr + 1));
            }
            return result;
        } catch (SAXException e) {
            throw new XPathException(this, e.getMessage());
        } finally {
            context.popDocumentContext();
        }
    }

}