/**
 * 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.openflowplugin.impl.device;

import com.google.common.base.Preconditions;
import com.google.common.base.Verify;
import com.google.common.collect.Iterators;
import io.netty.util.HashedWheelTimer;
import java.util.Collections;
import java.util.Iterator;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import javax.annotation.CheckForNull;
import javax.annotation.Nonnull;
import org.opendaylight.controller.md.sal.binding.api.DataBroker;
import org.opendaylight.controller.md.sal.binding.api.NotificationPublishService;
import org.opendaylight.controller.md.sal.binding.api.NotificationService;
import org.opendaylight.controller.md.sal.binding.api.WriteTransaction;
import org.opendaylight.controller.md.sal.common.api.data.LogicalDatastoreType;
import org.opendaylight.openflowjava.protocol.api.connection.ConnectionAdapter;
import org.opendaylight.openflowjava.protocol.api.connection.OutboundQueueHandlerRegistration;
import org.opendaylight.openflowplugin.api.openflow.connection.ConnectionContext;
import org.opendaylight.openflowplugin.api.openflow.connection.OutboundQueueProvider;
import org.opendaylight.openflowplugin.api.openflow.device.DeviceContext;
import org.opendaylight.openflowplugin.api.openflow.device.DeviceManager;
import org.opendaylight.openflowplugin.api.openflow.device.DeviceState;
import org.opendaylight.openflowplugin.api.openflow.device.TranslatorLibrary;
import org.opendaylight.openflowplugin.api.openflow.device.handlers.DeviceInitializationPhaseHandler;
import org.opendaylight.openflowplugin.api.openflow.statistics.ofpspecific.MessageIntelligenceAgency;
import org.opendaylight.openflowplugin.extension.api.ExtensionConverterProviderKeeper;
import org.opendaylight.openflowplugin.extension.api.core.extension.ExtensionConverterProvider;
import org.opendaylight.openflowplugin.impl.connection.OutboundQueueProviderImpl;
import org.opendaylight.openflowplugin.impl.device.listener.OpenflowProtocolListenerFullImpl;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodeId;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.Nodes;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.NodesBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.Node;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 */
public class DeviceManagerImpl implements DeviceManager, ExtensionConverterProviderKeeper {

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

    private static final long TICK_DURATION = 10; // 0.5 sec.
    private final long globalNotificationQuota;
    private final boolean switchFeaturesMandatory;
    private ScheduledThreadPoolExecutor spyPool;
    private final int spyRate = 10;

    private final DataBroker dataBroker;
    private final HashedWheelTimer hashedWheelTimer;
    private TranslatorLibrary translatorLibrary;
    private DeviceInitializationPhaseHandler deviceInitPhaseHandler;
    private NotificationService notificationService;
    private NotificationPublishService notificationPublishService;

    private final ConcurrentMap<NodeId, DeviceContext> deviceContexts = new ConcurrentHashMap<>();
    private final MessageIntelligenceAgency messageIntelligenceAgency;

    private final long barrierNanos = TimeUnit.MILLISECONDS.toNanos(500);
    private final int maxQueueDepth = 25600;
    private ExtensionConverterProvider extensionConverterProvider;

    public DeviceManagerImpl(@Nonnull final DataBroker dataBroker,
                             @Nonnull final MessageIntelligenceAgency messageIntelligenceAgency,
                             final long globalNotificationQuota, final boolean switchFeaturesMandatory) {
        this.switchFeaturesMandatory = switchFeaturesMandatory;
        this.globalNotificationQuota = globalNotificationQuota;
        this.dataBroker = Preconditions.checkNotNull(dataBroker);
        hashedWheelTimer = new HashedWheelTimer(TICK_DURATION, TimeUnit.MILLISECONDS, 500);
        /* merge empty nodes to oper DS to predict any problems with missing parent for Node */
        final WriteTransaction tx = dataBroker.newWriteOnlyTransaction();

        final NodesBuilder nodesBuilder = new NodesBuilder();
        nodesBuilder.setNode(Collections.<Node>emptyList());
        tx.merge(LogicalDatastoreType.OPERATIONAL, InstanceIdentifier.create(Nodes.class), nodesBuilder.build());
        try {
            tx.submit().get();
        } catch (ExecutionException | InterruptedException e) {
            LOG.error("Creation of node failed.", e);
            throw new IllegalStateException(e);
        }

        this.messageIntelligenceAgency = messageIntelligenceAgency;
    }


    @Override
    public void setDeviceInitializationPhaseHandler(final DeviceInitializationPhaseHandler handler) {
        deviceInitPhaseHandler = handler;
    }

    @Override
    public void onDeviceContextLevelUp(final DeviceContext deviceContext) throws Exception {
        // final phase - we have to add new Device to MD-SAL DataStore
        LOG.debug("Final phase of DeviceContextLevelUp for Node: {} ", deviceContext.getDeviceState().getNodeId());
        Preconditions.checkNotNull(deviceContext);
        ((DeviceContextImpl) deviceContext).initialSubmitTransaction();
        deviceContext.onPublished();
    }

    @Override
    public void deviceConnected(@CheckForNull final ConnectionContext connectionContext) throws Exception {
        Preconditions.checkArgument(connectionContext != null);
        Preconditions.checkState(!deviceContexts.containsKey(connectionContext.getNodeId()),
                "Rejecting connection from node which is already connected and there exist deviceContext for it: {}",
                connectionContext.getNodeId()
        );
        LOG.info("Initializing New Connection DeviceContext for node:{}", connectionContext.getNodeId());

        // Cache this for clarity
        final ConnectionAdapter connectionAdapter = connectionContext.getConnectionAdapter();

        //FIXME: as soon as auxiliary connection are fully supported then this is needed only before device context published
        connectionAdapter.setPacketInFiltering(true);

        final Short version = connectionContext.getFeatures().getVersion();
        final OutboundQueueProvider outboundQueueProvider = new OutboundQueueProviderImpl(version);

        connectionContext.setOutboundQueueProvider(outboundQueueProvider);
        final OutboundQueueHandlerRegistration<OutboundQueueProvider> outboundQueueHandlerRegistration =
                connectionAdapter.registerOutboundQueueHandler(outboundQueueProvider, maxQueueDepth, barrierNanos);
        connectionContext.setOutboundQueueHandleRegistration(outboundQueueHandlerRegistration);

        final DeviceState deviceState = createDeviceState(connectionContext);
        final DeviceContext deviceContext = new DeviceContextImpl(connectionContext, deviceState, dataBroker,
                hashedWheelTimer, messageIntelligenceAgency, outboundQueueProvider, translatorLibrary, switchFeaturesMandatory);

        Verify.verify(deviceContexts.putIfAbsent(connectionContext.getNodeId(), deviceContext) == null, "DeviceCtx still not closed.");
        deviceContext.addDeviceContextClosedHandler(this);

        ((ExtensionConverterProviderKeeper) deviceContext).setExtensionConverterProvider(extensionConverterProvider);
        deviceContext.setNotificationService(notificationService);
        deviceContext.setNotificationPublishService(notificationPublishService);

        updatePacketInRateLimiters();

        final OpenflowProtocolListenerFullImpl messageListener = new OpenflowProtocolListenerFullImpl(
                connectionAdapter, deviceContext);
        connectionAdapter.setMessageListener(messageListener);

        deviceCtxLevelUp(deviceContext);
    }

    private static DeviceStateImpl createDeviceState(final @Nonnull ConnectionContext connectionContext) {
        return new DeviceStateImpl(connectionContext.getFeatures(), connectionContext.getNodeId());
    }

    private void updatePacketInRateLimiters() {
        synchronized (deviceContexts) {
            final int deviceContextsSize = deviceContexts.size();
            if (deviceContextsSize > 0) {
                long freshNotificationLimit = globalNotificationQuota / deviceContextsSize;
                if (freshNotificationLimit < 100) {
                    freshNotificationLimit = 100;
                }
                LOG.debug("fresh notification limit = {}", freshNotificationLimit);
                for (final DeviceContext deviceContext : deviceContexts.values()) {
                    deviceContext.updatePacketInRateLimit(freshNotificationLimit);
                }
            }
        }
    }

    private void deviceCtxLevelUp(final DeviceContext deviceContext) throws Exception {
        deviceContext.getDeviceState().setValid(true);
        LOG.trace("Device context level up called.");
        deviceInitPhaseHandler.onDeviceContextLevelUp(deviceContext);
    }

    @Override
    public TranslatorLibrary oook() {
        return translatorLibrary;
    }

    @Override
    public void setTranslatorLibrary(final TranslatorLibrary translatorLibrary) {
        this.translatorLibrary = translatorLibrary;
    }

    @Override
    public void setNotificationService(final NotificationService notificationServiceParam) {
        notificationService = notificationServiceParam;
    }

    @Override
    public void setNotificationPublishService(final NotificationPublishService notificationService) {
        notificationPublishService = notificationService;
    }

    @Override
    public void close() {
        for (final Iterator<Entry<NodeId, DeviceContext>> iterator = Iterators
                .consumingIterator(deviceContexts.entrySet().iterator()); iterator.hasNext();) {
            iterator.next().getValue().close();
        }
    }

    @Override
    public void onDeviceContextClosed(final DeviceContext deviceContext) {
        LOG.trace("onDeviceContextClosed for Node {}", deviceContext.getDeviceState().getNodeId());
        deviceContexts.remove(deviceContext.getPrimaryConnectionContext().getNodeId());
        updatePacketInRateLimiters();
    }

    @Override
    public void initialize() {
        spyPool = new ScheduledThreadPoolExecutor(1);
        spyPool.scheduleAtFixedRate(messageIntelligenceAgency, spyRate, spyRate, TimeUnit.SECONDS);
    }

    @Override
    public void setExtensionConverterProvider(final ExtensionConverterProvider extensionConverterProvider) {
        this.extensionConverterProvider = extensionConverterProvider;
    }

    @Override
    public ExtensionConverterProvider getExtensionConverterProvider() {
        return extensionConverterProvider;
    }
}