/*
 *  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.taskdefs.condition.Condition;

import org.xmldb.api.DatabaseManager;
import org.xmldb.api.base.Collection;
import org.xmldb.api.base.Resource;
import org.xmldb.api.base.XMLDBException;


/**
 * an ant task to check for the existance of a collection or resource to be used as a ant condition.
 *
 * @author  peter.klotz@blue-elephant-systems.com
 */
public class XMLDBExistTask extends AbstractXMLDBTask implements Condition
{
    private String resource = null;

    /**
     * DOCUMENT ME!
     *
     * @return  returns true if the eval is successful.
     *
     * @throws  BuildException
     *
     * @see     org.apache.tools.ant.taskdefs.condition.Condition#eval()
     */
    public boolean eval() throws BuildException
    {
        boolean exist = false;

        if( uri == null ) {
            throw( new BuildException( "You have to specify an XMLDB collection URI" ) );
        }

        registerDatabase();

        try {
            log( "Checking collection: " + uri, Project.MSG_INFO );
            final Collection base = DatabaseManager.getCollection( uri, user, password );

            if( base != null ) {
                log( "Base collection found", Project.MSG_DEBUG );
                exist = true;
            }

            if( ( base != null ) && ( resource != null ) ) {
                log( "Checking resource: " + resource, Project.MSG_INFO );
                final Resource res = base.getResource( resource );

                if( res == null ) {
                    log( "Resource not found", Project.MSG_DEBUG );
                    exist = false;
                }
            }

        }
        catch( final XMLDBException e ) {

            // ignore is false already
            log( "Resource or collection cannot be retrieved", Project.MSG_DEBUG );
            exist = false;
        }

        return( exist );
    }


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