/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.cxf.ws.security.policy.custom;

import javax.xml.namespace.QName;

import org.w3c.dom.Element;

import org.apache.cxf.Bus;
import org.apache.cxf.helpers.DOMUtils;
import org.apache.neethi.Assertion;
import org.apache.neethi.AssertionBuilderFactory;
import org.apache.neethi.Policy;
import org.apache.neethi.builders.AssertionBuilder;
import org.apache.wss4j.policy.SP11Constants;
import org.apache.wss4j.policy.SP13Constants;
import org.apache.wss4j.policy.SPConstants;
import org.apache.wss4j.policy.SPUtils;
import org.apache.wss4j.policy.model.AlgorithmSuite;

public class AlgorithmSuiteBuilder implements AssertionBuilder<Element> {
    
    private Bus bus;

    public AlgorithmSuiteBuilder(Bus bus) {
        this.bus = bus;
    }
    
    @Override
    public Assertion build(Element element, AssertionBuilderFactory factory) throws IllegalArgumentException {

        final SPConstants.SPVersion spVersion = SPConstants.SPVersion.getSPVersion(element.getNamespaceURI());
        final Element nestedPolicyElement = SPUtils.getFirstPolicyChildElement(element);
        if (nestedPolicyElement == null) {
            throw new IllegalArgumentException("sp:AlgorithmSuite must have an inner wsp:Policy element");
        }
        final Policy nestedPolicy = factory.getPolicyEngine().getPolicy(nestedPolicyElement);
        
        AlgorithmSuiteLoader loader = bus.getExtension(AlgorithmSuiteLoader.class);
        if (loader == null) {
            loader = new DefaultAlgorithmSuiteLoader();
        }
        AlgorithmSuite algorithmSuite = loader.getAlgorithmSuite(bus, spVersion, nestedPolicy);
        if (algorithmSuite == null || algorithmSuite.getAlgorithmSuiteType() == null) {
            String algorithmSuiteName = DOMUtils.getFirstElement(nestedPolicyElement).getLocalName();
            throw new IllegalArgumentException(
                "Algorithm suite \"" + algorithmSuiteName + "\" is not registered"
            );
        }

        algorithmSuite.setOptional(SPUtils.isOptional(element));
        algorithmSuite.setIgnorable(SPUtils.isIgnorable(element));
        return algorithmSuite;
    }

    @Override
    public QName[] getKnownElements() {
        return new QName[]{SP13Constants.ALGORITHM_SUITE, SP11Constants.ALGORITHM_SUITE};
    }

}
