/*-
 * ============LICENSE_START=======================================================
 *  Copyright (C) 2016-2018 Ericsson. All rights reserved.
 * ================================================================================
 * 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.
 * 
 * SPDX-License-Identifier: Apache-2.0
 * ============LICENSE_END=========================================================
 */

package org.onap.policy.apex.plugins.context.distribution.infinispan;

import java.io.IOException;

import org.infinispan.manager.DefaultCacheManager;
import org.infinispan.manager.EmbeddedCacheManager;
import org.onap.policy.apex.context.ContextException;
import org.slf4j.ext.XLogger;
import org.slf4j.ext.XLoggerFactory;

/**
 * The Class InfinispanManager holds the Infinispan cache manager for a JVM.
 */
public class InfinispanManager {
    // Logger for this class
    private static final XLogger LOGGER = XLoggerFactory.getXLogger(InfinispanManager.class);

    // The Infinispan Cache Manager
    private EmbeddedCacheManager cacheManager;

    /**
     * Constructor, set up an Infinispan cache manager.
     *
     * @param infinispanDistributorParameters the infinispan distributor parameters
     * @throws ContextException On errors connecting to Infinispan
     */
    public InfinispanManager(final InfinispanDistributorParameters infinispanDistributorParameters)
                    throws ContextException {
        LOGGER.entry("Creating Infinispan Manager: " + infinispanDistributorParameters);

        setSystemProperties(infinispanDistributorParameters);

        try {
            LOGGER.debug("starting infinispan cache manager using specified configuration . . .");
            cacheManager = new DefaultCacheManager(infinispanDistributorParameters.getConfigFile());
            LOGGER.debug("started infinispan cache manager using specified configuration");
        } catch (final IOException ioException) {
            final String errorMessage = "failed to start infinispan cache manager, "
                            + "no infinispan configuration found on local file system or in classpath, "
                            + "try setting Infinspan \"configFile\" parameter";
            LOGGER.error(errorMessage);
            throw new ContextException(errorMessage, ioException);
        } catch (final Exception e) {
            LOGGER.error("failed to start infinispan cache manager using specified configuration", e);
            throw new ContextException("failed to start infinispan cache manager using specified configuration", e);
        }

        // Start the cache manager
        cacheManager.start();

        Runtime.getRuntime().addShutdownHook(new InfinspanManagerShutdownHook());

        LOGGER.exit("Created Infinispan Manager: " + infinispanDistributorParameters);
    }

    /**
     * Shutdown the manager.
     */
    public void shutdown() {
        if (cacheManager == null) {
            return;
        }

        cacheManager.stop();
        cacheManager = null;
    }

    /**
     * Get the cache manager.
     *
     * @return the infinispan cache manager
     */
    public EmbeddedCacheManager getCacheManager() {
        return cacheManager;
    }

    /**
     * Set system properties used by Infinispan.
     *
     * @param infinispanDistributorParameters The parameter values to set are passed as properties
     */
    private void setSystemProperties(final InfinispanDistributorParameters infinispanDistributorParameters) {
        System.setProperty("java.net.preferIPv4Stack",
                        Boolean.toString(infinispanDistributorParameters.preferIPv4Stack()));
        System.setProperty("jgroups.bind_addr", infinispanDistributorParameters.getjGroupsBindAddress());
    }

    /**
     * Private class to implement the shutdown hook for this infinispan manager.
     */
    public class InfinspanManagerShutdownHook extends Thread {
        /**
         * {@inheritDoc}.
         */
        @Override
        public void run() {
            shutdown();
        }
    }
}