/*
 *  eXist Open Source Native XML Database
 *  Copyright (C) 2010 The eXist Project
 *  http://exist-db.org
 *
 *  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 library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *  $Id$
 */
package org.exist.ant;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.PropertyHelper;

import org.xmldb.api.DatabaseManager;
import org.xmldb.api.base.Collection;
import org.xmldb.api.base.ResourceSet;
import org.xmldb.api.base.XMLDBException;
import org.xmldb.api.modules.XPathQueryService;


/**
 * Ant task to execute an XQuery.
 *
 * <p>The query is either passed as nested text in the element, or via an attribute "query".</p>
 *
 * <p>Please note that the task doesn't output the query results.</p>
 *
 * @author  wolf
 */
public class XMLDBQueryTask extends AbstractXMLDBTask
{
    private String query = null;
    private String text  = null;

    /* (non-Javadoc)
     * @see org.apache.tools.ant.Task#execute()
     */
    public void execute() throws BuildException
    {
        if( uri == null ) {
            throw( new BuildException( "you have to specify an XMLDB collection URI" ) );
        }

        if( text != null ) {
            final PropertyHelper helper = PropertyHelper.getPropertyHelper( getProject() );
            query = helper.replaceProperties( null, text, null );
        }

        if( query == null ) {
            throw( new BuildException( "you have to specify a query" ) );
        }

        log( "XQuery is:\n" + query, org.apache.tools.ant.Project.MSG_DEBUG );

        registerDatabase();

        try {
            final Collection collection = DatabaseManager.getCollection( uri, user, password );

            if( collection == null ) {
                final String msg = "Collection " + uri + " could not be found.";

                if( failonerror ) {
                    throw( new BuildException( msg ) );
                } else {
                    log( msg, Project.MSG_ERR );
                }

            } else {
                final XPathQueryService service = (XPathQueryService)collection.getService( "XPathQueryService", "1.0" );
                final ResourceSet       results = service.query( query );
                log( "Found " + results.getSize() );
            }

        }
        catch( final XMLDBException e ) {
            final String msg = "XMLDB exception caught while executing query: " + e.getMessage();

            if( failonerror ) {
                throw( new BuildException( msg, e ) );
            } else {
                log( msg, e, Project.MSG_ERR );
            }
        }
    }


    /**
     * DOCUMENT ME!
     *
     * @param  query
     */
    public void setQuery( String query )
    {
        this.query = query;
    }


    public void addText( String text )
    {
        this.text = text;
    }
}