/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates
 * and other contributors as indicated by the @author tags.
 *
 * 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.keycloak.saml.processing.core.parsers.saml;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.events.EndElement;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
import org.keycloak.dom.saml.v2.protocol.ExtensionsType;
import org.keycloak.saml.common.PicketLinkLogger;
import org.keycloak.saml.common.PicketLinkLoggerFactory;
import org.keycloak.saml.common.constants.JBossSAMLConstants;
import org.keycloak.saml.common.constants.JBossSAMLURIConstants;
import org.keycloak.saml.common.exceptions.ParsingException;
import org.keycloak.saml.common.parsers.ParserNamespaceSupport;
import org.keycloak.saml.common.util.StaxParserUtil;

/**
 * Parses <samlp:Extensions> SAML2 element into series of DOM nodes.
 *
 * @author hmlnarik
 */
public class SAMLExtensionsParser implements ParserNamespaceSupport {

    private static final String EXTENSIONS = JBossSAMLConstants.EXTENSIONS.get();

    private static final PicketLinkLogger logger = PicketLinkLoggerFactory.getLogger();

    @Override
    public ExtensionsType parse(XMLEventReader xmlEventReader) throws ParsingException {
        // Get the startelement
        StartElement startElement = StaxParserUtil.getNextStartElement(xmlEventReader);
        StaxParserUtil.validate(startElement, EXTENSIONS);

        ExtensionsType extensions = new ExtensionsType();

        while (xmlEventReader.hasNext()) {
            XMLEvent xmlEvent = StaxParserUtil.peek(xmlEventReader);
            if (xmlEvent instanceof EndElement) {
                EndElement endElement = (EndElement) xmlEvent;
                if (StaxParserUtil.matches(endElement, EXTENSIONS)) {
                    endElement = StaxParserUtil.getNextEndElement(xmlEventReader);
                    break;
                } else
                    throw logger.parserUnknownEndElement(StaxParserUtil.getEndElementName(endElement));
            }

            startElement = StaxParserUtil.peekNextStartElement(xmlEventReader);
            if (startElement == null)
                break;

            extensions.addExtension(StaxParserUtil.getDOMElement(xmlEventReader));
        }

        return extensions;
    }

    @Override
    public boolean supports(QName qname) {
        String nsURI = qname.getNamespaceURI();
        String localPart = qname.getLocalPart();

        return nsURI.equals(JBossSAMLURIConstants.PROTOCOL_NSURI.get())
                && localPart.equals(JBossSAMLConstants.EXTENSIONS.get());
    }

}