/*
 * 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.tomee.security.servlet;

import org.apache.tomee.security.cdi.TomEESecurityExtension;
import org.apache.tomee.security.provider.TomEESecurityAuthConfigProvider;

import javax.enterprise.inject.spi.BeanManager;
import javax.enterprise.inject.spi.CDI;
import javax.security.auth.message.config.AuthConfigFactory;
import javax.servlet.ServletContainerInitializer;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.ServletException;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.HashMap;
import java.util.Set;

public class TomEESecurityServletContainerInitializer implements ServletContainerInitializer, ServletContextListener {

    public static final String CONTEXT_REGISTRATION_ID = "org.apache.tomee.security.message.registrationId";

    @Override
    public void onStartup(final Set<Class<?>> c, final ServletContext ctx) throws ServletException {

        TomEESecurityExtension securityExtension;
        try {
            final BeanManager beanManager = getBeanManager();
            securityExtension = beanManager.getExtension(TomEESecurityExtension.class);

        } catch (final IllegalStateException e) {

            // CDI not enabled?
            return;

        } catch (final IllegalArgumentException e) {

            // Extension not available?
            return;
        }

        if (securityExtension.hasAuthenticationMechanisms()) {
            final String registrationId = AccessController.doPrivileged(new PrivilegedAction<String>() {
                public String run() {
                    return AuthConfigFactory.getFactory().registerConfigProvider(
                        new TomEESecurityAuthConfigProvider(new HashMap(), null), // todo we can probably do better
                        "HttpServlet",                                              // from AuthenticatorBase.java:1245
                        ctx.getVirtualServerName() + " " + ctx.getContextPath(),    // from AuthenticatorBase.java:1178
                        "TomEE Security JSR-375");
                }
            });

            if (registrationId != null) {
                ctx.setAttribute(CONTEXT_REGISTRATION_ID, registrationId);
            }
        }
    }

    private BeanManager getBeanManager() throws IllegalStateException {
        return CDI.current().getBeanManager();
    }

    @Override
    public void contextDestroyed(final ServletContextEvent sce) {
        String registrationId = (String) sce.getServletContext().getAttribute(CONTEXT_REGISTRATION_ID);
        if (registrationId != null && registrationId.length() > 0) {
            AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
                public Boolean run() {
                    return AuthConfigFactory.getFactory().removeRegistration(registrationId);
                }
            });
        }
    }
}
