/**
 * Copyright (c) 2013 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.openflowplugin.learningswitch;

import org.opendaylight.controller.md.sal.binding.api.DataBroker;
import org.opendaylight.controller.md.sal.binding.api.DataTreeChangeListener;
import org.opendaylight.controller.md.sal.binding.api.DataTreeIdentifier;
import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
import org.opendaylight.controller.sal.binding.api.NotificationService;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.FlowCapableNode;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.tables.Table;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.Nodes;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.Node;
import org.opendaylight.yang.gen.v1.urn.opendaylight.packet.service.rev130709.PacketProcessingService;
import org.opendaylight.yangtools.concepts.ListenerRegistration;
import org.opendaylight.yangtools.concepts.Registration;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Listens to packetIn notification.
 * <ul>
 * <li>in HUB mode simply floods all switch ports (except ingress port)</li>
 * <li>in LSWITCH mode collects source MAC address of packetIn and bind it with ingress port.
 * If target MAC address is already bound then a flow is created (for direct communication between
 * corresponding MACs)</li>
 * </ul>
 */
public class LearningSwitchManagerSimpleImpl
        implements DataTreeChangeListenerRegistrationHolder, LearningSwitchManager {

    private static final Logger LOG = LoggerFactory.getLogger(LearningSwitchManagerSimpleImpl.class);
    private NotificationService notificationService;
    private PacketProcessingService packetProcessingService;
    private DataBroker data;
    private Registration packetInRegistration;
    private ListenerRegistration<DataTreeChangeListener> dataTreeChangeListenerRegistration;

    /**
     * Sets the NotificationService.
     *
     * @param notificationService the notificationService to set
     */
    @Override
    public void setNotificationService(NotificationService notificationService) {
        this.notificationService = notificationService;
    }

    /**
     * Sets the PacketProcessingService.
     *
     * @param packetProcessingService the packetProcessingService to set
     */
    @Override
    public void setPacketProcessingService(
            PacketProcessingService packetProcessingService) {
        this.packetProcessingService = packetProcessingService;
    }

    /**
     * Sets the DataBroker.
     */
    @Override
    public void setDataBroker(DataBroker broker) {
        this.data = broker;
    }

    /**
     * Starts learning switch.
     */
    @Override
    public void start() {
        LOG.debug("start() -->");
        FlowCommitWrapper dataStoreAccessor = new FlowCommitWrapperImpl(data);

        LearningSwitchHandlerSimpleImpl learningSwitchHandler = new LearningSwitchHandlerSimpleImpl(dataStoreAccessor,
                packetProcessingService, this);
        packetInRegistration = notificationService.registerNotificationListener(learningSwitchHandler);

        WakeupOnNode wakeupListener = new WakeupOnNode();
        wakeupListener.setLearningSwitchHandler(learningSwitchHandler);
        final InstanceIdentifier<Table> instanceIdentifier = InstanceIdentifier.create(Nodes.class)
                .child(Node.class)
                .augmentation(FlowCapableNode.class)
                .child(Table.class);
        final DataTreeIdentifier<Table> dataTreeIdentifier =
                new DataTreeIdentifier<>(LogicalDatastoreType.OPERATIONAL, instanceIdentifier);
        dataTreeChangeListenerRegistration = data.registerDataTreeChangeListener(dataTreeIdentifier, wakeupListener);
        LOG.debug("start() <--");
    }

    /**
     * Stops the learning switch.
     */
    @Override
    public void stop() {
        LOG.debug("stop() -->");
        //TODO: remove flow (created in #start())

        packetInRegistration.close();

        dataTreeChangeListenerRegistration.close();

        LOG.debug("stop() <--");
    }

    @Override
    public ListenerRegistration<DataTreeChangeListener> getDataTreeChangeListenerRegistration() {
        return dataTreeChangeListenerRegistration;
    }
}