/*
 * Copyright (c) 2016 Ericsson India Global Services Pvt Ltd. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.netvirt.dhcpservice;

import java.util.ArrayList;
import javax.annotation.PreDestroy;
import javax.inject.Inject;
import javax.inject.Singleton;
import org.eclipse.jdt.annotation.Nullable;
import org.opendaylight.infrautils.utils.concurrent.Executors;
import org.opendaylight.mdsal.binding.api.DataBroker;
import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
import org.opendaylight.netvirt.dhcpservice.api.DhcpMConstants;
import org.opendaylight.serviceutils.tools.listener.AbstractClusteredAsyncDataTreeChangeListener;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.DhcpConfig;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.neutronvpn.rev150602.dhcp.config.Configs;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Singleton
public class DhcpConfigListener extends AbstractClusteredAsyncDataTreeChangeListener<DhcpConfig> {

    private static final Logger LOG = LoggerFactory.getLogger(DhcpConfigListener.class);

    private final DhcpManager dhcpManager;
    private final DataBroker dataBroker;

    @Inject
    public DhcpConfigListener(final DataBroker db, final DhcpManager dhcpMgr) {
        super(db, LogicalDatastoreType.CONFIGURATION, InstanceIdentifier.create(DhcpConfig.class),
                Executors.newListeningSingleThreadExecutor("DhcpConfigListener", LOG));
        dhcpManager = dhcpMgr;
        this.dataBroker = db;
    }

    public void init() {
        LOG.info("{} close", getClass().getSimpleName());
    }

    @Override
    @PreDestroy
    public void close() {
        super.close();
        Executors.shutdownAndAwaitTermination(getExecutorService());
        LOG.debug("DhcpConfig Listener Closed");
    }

    @Override
    public void remove(InstanceIdentifier<DhcpConfig> identifier, DhcpConfig del) {
        LOG.trace("DhcpConfig removed: {}", del);
        updateConfig(null);
    }

    @Override
    public void update(InstanceIdentifier<DhcpConfig> identifier, DhcpConfig original, DhcpConfig update) {
        LOG.trace("DhcpConfig changed to {}", update);
        updateConfig(update);
    }

    @Override
    public void add(InstanceIdentifier<DhcpConfig> identifier, DhcpConfig add) {
        LOG.trace("DhcpConfig added {}", add);
        updateConfig(add);
    }

    private void updateConfig(@Nullable DhcpConfig update) {
        //TODO: Update operational with actual values
        if (update == null || update.getConfigs() == null || update.getConfigs().isEmpty()) {
            dhcpManager.setLeaseDuration(DhcpMConstants.DEFAULT_LEASE_TIME);
            dhcpManager.setDefaultDomain(DhcpMConstants.DEFAULT_DOMAIN_NAME);
            return;
        }
        Configs config = new ArrayList<Configs>(update.getConfigs().values()).get(0);
        if (config.getLeaseDuration() != null) {
            dhcpManager.setLeaseDuration(config.getLeaseDuration());
        }
        if (config.getDefaultDomain() != null) {
            dhcpManager.setDefaultDomain(config.getDefaultDomain());
            //TODO: What to do if string is ""
        }
    }
}