/*
 * 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.broker.saml;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;

import javax.xml.stream.XMLEventReader;

import org.keycloak.broker.provider.DefaultDataMarshaller;
import org.keycloak.dom.saml.v2.assertion.AssertionType;
import org.keycloak.dom.saml.v2.assertion.AuthnStatementType;
import org.keycloak.dom.saml.v2.protocol.ResponseType;
import org.keycloak.saml.common.exceptions.ParsingException;
import org.keycloak.saml.common.exceptions.ProcessingException;
import org.keycloak.saml.common.util.StaxUtil;
import org.keycloak.saml.processing.core.parsers.saml.SAMLParser;
import org.keycloak.saml.processing.core.parsers.util.SAMLParserUtil;
import org.keycloak.saml.processing.core.saml.v2.writers.SAMLAssertionWriter;
import org.keycloak.saml.processing.core.saml.v2.writers.SAMLResponseWriter;

/**
 * @author <a href="mailto:mposolda@redhat.com">Marek Posolda</a>
 */
public class SAMLDataMarshaller extends DefaultDataMarshaller {

    @Override
    public String serialize(Object obj) {

        // Lame impl, but hopefully sufficient for now. See if something better is needed...
        if (obj.getClass().getName().startsWith("org.keycloak.dom.saml")) {
            ByteArrayOutputStream bos = new ByteArrayOutputStream();

            try {
                if (obj instanceof ResponseType) {
                    ResponseType responseType = (ResponseType) obj;
                    SAMLResponseWriter samlWriter = new SAMLResponseWriter(StaxUtil.getXMLStreamWriter(bos));
                    samlWriter.write(responseType);
                } else if (obj instanceof AssertionType) {
                    AssertionType assertion = (AssertionType) obj;
                    SAMLAssertionWriter samlWriter = new SAMLAssertionWriter(StaxUtil.getXMLStreamWriter(bos));
                    samlWriter.write(assertion);
                } else if (obj instanceof AuthnStatementType) {
                    AuthnStatementType authnStatement = (AuthnStatementType) obj;
                    SAMLAssertionWriter samlWriter = new SAMLAssertionWriter(StaxUtil.getXMLStreamWriter(bos));
                    samlWriter.write(authnStatement, true);
                } else {
                    throw new IllegalArgumentException("Don't know how to serialize object of type " + obj.getClass().getName());
                }
            } catch (ProcessingException pe) {
                throw new RuntimeException(pe);
            }

            return new String(bos.toByteArray());
        } else {
            return super.serialize(obj);
        }
    }

    @Override
    public <T> T deserialize(String serialized, Class<T> clazz) {
        if (clazz.getName().startsWith("org.keycloak.dom.saml")) {
            String xmlString = serialized;

            try {
                if (clazz.equals(ResponseType.class) || clazz.equals(AssertionType.class)) {
                    byte[] bytes = xmlString.getBytes();
                    InputStream is = new ByteArrayInputStream(bytes);
                    Object respType = new SAMLParser().parse(is);
                    return clazz.cast(respType);
                } else if (clazz.equals(AuthnStatementType.class)) {
                    byte[] bytes = xmlString.getBytes();
                    InputStream is = new ByteArrayInputStream(bytes);
                    XMLEventReader xmlEventReader = new SAMLParser().createEventReader(is);
                    AuthnStatementType authnStatement = SAMLParserUtil.parseAuthnStatement(xmlEventReader);
                    return clazz.cast(authnStatement);
                } else {
                    throw new IllegalArgumentException("Don't know how to deserialize object of type " + clazz.getName());
                }
            } catch (ParsingException pe) {
                throw new RuntimeException(pe);
            }

        } else {
            return super.deserialize(serialized, clazz);
        }
    }

}
