/*
 * Copyright 2001-2004 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.ws.secpolicy12.builders;

import java.util.Iterator;
import java.util.List;

import javax.xml.namespace.QName;

import org.apache.axiom.om.OMElement;
import org.apache.neethi.Assertion;
import org.apache.neethi.AssertionBuilderFactory;
import org.apache.neethi.Policy;
import org.apache.neethi.PolicyEngine;
import org.apache.neethi.builders.AssertionBuilder;
import org.apache.ws.secpolicy.SPConstants;
import org.apache.ws.secpolicy.SP12Constants;
import org.apache.ws.secpolicy.model.RecipientToken;
import org.apache.ws.secpolicy.model.Token;

public class RecipientTokenBuilder implements AssertionBuilder<OMElement> {

    public Assertion build(OMElement element, AssertionBuilderFactory factory)
            throws IllegalArgumentException {
        RecipientToken recipientToken = new RecipientToken(SPConstants.SP_V12);
        
        Policy policy = PolicyEngine.getPolicy(element.getFirstElement());
        policy = (Policy) policy.normalize(false);
        
        for (Iterator<List<Assertion>> iterator = policy.getAlternatives(); iterator.hasNext();) {
            processAlternative(iterator.next(), recipientToken);
            
            /* 
             * for the moment we will pick the first token specified in the policy
             */
            break;   
        }
        
        return recipientToken;
    }

    private void processAlternative(List<Assertion> assertions, RecipientToken parent) {
        
        Assertion assertion;
        
        for (Iterator<Assertion> iterator = assertions.iterator(); iterator.hasNext();) {
            assertion = (Assertion) iterator.next();
            
            if (assertion instanceof Token) {
                parent.setToken((Token) assertion);
            }
        }        
    }
    
    public QName[] getKnownElements() {
        return new QName[] {SP12Constants.RECIPIENT_TOKEN};
    }

}