/*
 * Copyright (c) 2015 Cisco Systems, Inc. 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.netconf.topology.impl;

import com.google.common.util.concurrent.FutureCallback;
import com.google.common.util.concurrent.Futures;
import io.netty.util.concurrent.EventExecutor;
import java.util.Collection;
import javax.annotation.Nonnull;
import org.opendaylight.controller.config.threadpool.ScheduledThreadPool;
import org.opendaylight.controller.config.threadpool.ThreadPool;
import org.opendaylight.controller.md.sal.binding.api.DataBroker;
import org.opendaylight.controller.md.sal.binding.api.DataObjectModification;
import org.opendaylight.controller.md.sal.binding.api.DataTreeChangeListener;
import org.opendaylight.controller.md.sal.binding.api.DataTreeIdentifier;
import org.opendaylight.controller.md.sal.binding.api.DataTreeModification;
import org.opendaylight.controller.md.sal.binding.api.WriteTransaction;
import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
import org.opendaylight.controller.md.sal.dom.api.DOMMountPointService;
import org.opendaylight.controller.sal.binding.api.BindingAwareBroker;
import org.opendaylight.controller.sal.core.api.Broker;
import org.opendaylight.netconf.client.NetconfClientDispatcher;
import org.opendaylight.netconf.sal.connect.api.RemoteDeviceHandler;
import org.opendaylight.netconf.sal.connect.netconf.listener.NetconfSessionPreferences;
import org.opendaylight.netconf.sal.connect.netconf.sal.NetconfDeviceSalFacade;
import org.opendaylight.netconf.sal.connect.util.RemoteDeviceId;
import org.opendaylight.netconf.topology.AbstractNetconfTopology;
import org.opendaylight.netconf.topology.api.SchemaRepositoryProvider;
import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.NetworkTopology;
import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.NetworkTopologyBuilder;
import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.TopologyId;
import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.Topology;
import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.TopologyBuilder;
import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.TopologyKey;
import org.opendaylight.yang.gen.v1.urn.tbd.params.xml.ns.yang.network.topology.rev131021.network.topology.topology.Node;
import org.opendaylight.yangtools.concepts.ListenerRegistration;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class NetconfTopologyImpl extends AbstractNetconfTopology implements DataTreeChangeListener<Node>, AutoCloseable {

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

    private ListenerRegistration<NetconfTopologyImpl> datastoreListenerRegistration = null;

    public NetconfTopologyImpl(final String topologyId, final NetconfClientDispatcher clientDispatcher,
                               final BindingAwareBroker bindingAwareBroker, final Broker domBroker,
                               final EventExecutor eventExecutor, final ScheduledThreadPool keepaliveExecutor,
                               final ThreadPool processingExecutor, final SchemaRepositoryProvider schemaRepositoryProvider,
                               final DataBroker dataBroker, final DOMMountPointService mountPointService) {
        super(topologyId, clientDispatcher,
                bindingAwareBroker, domBroker, eventExecutor,
                keepaliveExecutor, processingExecutor, schemaRepositoryProvider, dataBroker, mountPointService);
    }

    @Override
    public void close() throws Exception {
        // close all existing connectors, delete whole topology in datastore?
        for (NetconfConnectorDTO connectorDTO : activeConnectors.values()) {
            connectorDTO.close();
        }
        activeConnectors.clear();

        if (datastoreListenerRegistration != null) {
            datastoreListenerRegistration.close();
            datastoreListenerRegistration = null;
        }
    }

    @Override
    protected RemoteDeviceHandler<NetconfSessionPreferences> createSalFacade(RemoteDeviceId id, Broker domBroker, BindingAwareBroker bindingBroker) {
        return new NetconfDeviceSalFacade(id, domBroker, bindingAwareBroker);
    }

    /**
     * Invoke by blueprint
     */
    public void init() {
        final WriteTransaction wtx = dataBroker.newWriteOnlyTransaction();
        initTopology(wtx, LogicalDatastoreType.CONFIGURATION);
        initTopology(wtx, LogicalDatastoreType.OPERATIONAL);
        Futures.addCallback(wtx.submit(), new FutureCallback<Void>() {
            @Override
            public void onSuccess(Void result) {
                LOG.debug("topology initialization successful");
            }

            @Override
            public void onFailure(Throwable t) {
                LOG.error("Unable to initialize netconf-topology, {}", t);
            }
        });

        LOG.debug("Registering datastore listener");
        datastoreListenerRegistration =
                dataBroker.registerDataTreeChangeListener(
                        new DataTreeIdentifier<>(LogicalDatastoreType.CONFIGURATION,
                                TopologyUtil.createTopologyListPath(topologyId).child(Node.class)), this);


    }

    @Override
    public void onDataTreeChanged(@Nonnull Collection<DataTreeModification<Node>> collection) {
        for (DataTreeModification<Node> change : collection) {
            final DataObjectModification<Node> rootNode = change.getRootNode();
            switch (rootNode.getModificationType()) {
                case SUBTREE_MODIFIED:
                    LOG.debug("Config for node {} updated", TopologyUtil.getNodeId(rootNode.getIdentifier()));
                    disconnectNode(TopologyUtil.getNodeId(rootNode.getIdentifier()));
                    connectNode(TopologyUtil.getNodeId(rootNode.getIdentifier()), rootNode.getDataAfter());
                    break;
                case WRITE:
                    LOG.debug("Config for node {} created", TopologyUtil.getNodeId(rootNode.getIdentifier()));
                    if (activeConnectors.containsKey(TopologyUtil.getNodeId(rootNode.getIdentifier()))) {
                        LOG.warn("RemoteDevice{{}} was already configured, reconfiguring..", TopologyUtil.getNodeId(rootNode.getIdentifier()));
                        disconnectNode(TopologyUtil.getNodeId(rootNode.getIdentifier()));
                    }
                    connectNode(TopologyUtil.getNodeId(rootNode.getIdentifier()), rootNode.getDataAfter());
                    break;
                case DELETE:
                    LOG.debug("Config for node {} deleted", TopologyUtil.getNodeId(rootNode.getIdentifier()));
                    disconnectNode(TopologyUtil.getNodeId(rootNode.getIdentifier()));
                    break;
            }
        }
    }

    private void initTopology(final WriteTransaction wtx, final LogicalDatastoreType datastoreType) {
        final NetworkTopology networkTopology = new NetworkTopologyBuilder().build();
        final InstanceIdentifier<NetworkTopology> networkTopologyId = InstanceIdentifier.builder(NetworkTopology.class).build();
        wtx.merge(datastoreType, networkTopologyId, networkTopology);
        final Topology topology = new TopologyBuilder().setTopologyId(new TopologyId(topologyId)).build();
        wtx.merge(datastoreType, networkTopologyId.child(Topology.class, new TopologyKey(new TopologyId(topologyId))), topology);
    }

}