/*
 * Copyright  1999-2004 The Apache Software Foundation.
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package org.apache.savan.filters;

import org.apache.axiom.om.OMElement;
import org.apache.axiom.om.OMNode;
import org.apache.axiom.om.OMText;
import org.apache.axiom.om.xpath.AXIOMXPath;
import org.apache.savan.SavanException;
import org.jaxen.JaxenException;

import java.util.List;

/** A filter that does filtering of messages based on a XPath string. */
public class XPathBasedFilter implements Filter {

    public static String XPATH_BASED_FILTER = "http://www.w3.org/TR/1999/REC-xpath-19991116";

    private String XPathString = null;

    public String getXPathString() {
        return XPathString;
    }

    public void setXPathString(String XPathString) {
        this.XPathString = XPathString;
    }

    /** This method may fail due to the JIRA issues WS-Commons(40) amd WS-Commons (41) */
    public boolean checkCompliance(OMElement element) throws SavanException {

        if (XPathString == null)
            return true;

        try {
            AXIOMXPath xpath = new AXIOMXPath(XPathString);
            List resultList = xpath.selectNodes(element);

            return resultList.size() > 0;
        } catch (JaxenException e) {
            throw new SavanException(e);
        }
    }

    public void setUp(OMNode element) {
        if (!(element instanceof OMText))
            throw new IllegalArgumentException("Cannot determine a valid XPath string");

        OMText text = (OMText)element;
        XPathString = text.getText();
    }

    public Object getFilterValue() {
        return XPathString;
    }


}