/*
 * 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.neutronvpn;

import static org.opendaylight.netvirt.neutronvpn.NeutronvpnUtils.buildfloatingIpIdToPortMappingIdentifier;

import edu.umd.cs.findbugs.annotations.CheckReturnValue;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import javax.annotation.PreDestroy;
import javax.inject.Inject;
import javax.inject.Singleton;
import org.opendaylight.genius.datastoreutils.SingleTransactionDataBroker;
import org.opendaylight.genius.mdsalutil.MDSALUtil;
import org.opendaylight.infrautils.utils.concurrent.Executors;
import org.opendaylight.infrautils.utils.concurrent.NamedLocks;
import org.opendaylight.infrautils.utils.concurrent.NamedSimpleReentrantLock.AcquireResult;
import org.opendaylight.mdsal.binding.api.DataBroker;
import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
import org.opendaylight.serviceutils.tools.listener.AbstractAsyncDataTreeChangeListener;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev130715.IpAddress;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.yang.types.rev130715.Uuid;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.FloatingIpInfo;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.RouterPorts;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.RouterPortsBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.RouterPortsKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.router.ports.Ports;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.router.ports.PortsBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.router.ports.PortsKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.router.ports.ports.InternalToExternalPortMap;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.router.ports.ports.InternalToExternalPortMapBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.info.router.ports.ports.InternalToExternalPortMapKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.port.info.FloatingIpIdToPortMapping;
import org.opendaylight.yang.gen.v1.urn.opendaylight.netvirt.natservice.rev160111.floating.ip.port.info.FloatingIpIdToPortMappingBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.l3.rev150712.floatingips.attributes.Floatingips;
import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.l3.rev150712.floatingips.attributes.floatingips.Floatingip;
import org.opendaylight.yang.gen.v1.urn.opendaylight.neutron.rev150712.Neutron;
import org.opendaylight.yangtools.yang.binding.InstanceIdentifier;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Singleton
public class NeutronFloatingToFixedIpMappingChangeListener extends AbstractAsyncDataTreeChangeListener<Floatingip> {
    private static final Logger LOG = LoggerFactory.getLogger(NeutronFloatingToFixedIpMappingChangeListener.class);
    private static final long LOCK_WAIT_TIME = 10L;

    private final DataBroker dataBroker;
    private final NamedLocks<String> routerLock = new NamedLocks<>();

    @Inject
    public NeutronFloatingToFixedIpMappingChangeListener(final DataBroker dataBroker) {
        super(dataBroker, LogicalDatastoreType.CONFIGURATION, InstanceIdentifier.create(Neutron.class)
                        .child(Floatingips.class).child(Floatingip.class),
                Executors.newSingleThreadExecutor("NeutronFloatingToFixedIpMappingChangeListener", LOG));
        this.dataBroker = dataBroker;
    }

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

    @Override
    @PreDestroy
    public void close() {
        super.close();
        Executors.shutdownAndAwaitTermination(getExecutorService());
    }

    @Override
    public void add(InstanceIdentifier<Floatingip> identifier, Floatingip input) {
        LOG.trace("Neutron Floating IP created: key: {}, value={}", identifier, input);
        IpAddress fixedIp = input.getFixedIpAddress();
        String floatingIp = input.getFloatingIpAddress().getIpv4Address().getValue();
        if (fixedIp != null) {
            addToFloatingIpInfo(input.getRouterId().getValue(), input.getFloatingNetworkId(), input.getPortId()
                    .getValue(), fixedIp.getIpv4Address().getValue(), floatingIp, input.getUuid());
        }
    }

    @Override
    public void remove(InstanceIdentifier<Floatingip> identifier, Floatingip input) {
        LOG.trace("Neutron Floating IP deleted : key: {}, value={}", identifier, input);
        IpAddress fixedIp = input.getFixedIpAddress();
        if (fixedIp != null) {
            // update FloatingIpPortInfo to set isFloatingIpDeleted as true to enable deletion of FloatingIpPortInfo
            // map once it is used for processing in the NAT removal path
            updateFloatingIpPortInfo(input.getUuid(), input.getPortId());
            clearFromFloatingIpInfo(input.getRouterId().getValue(), input.getPortId().getValue(), fixedIp
                    .getIpv4Address().getValue());
        } else {
            // delete FloatingIpPortInfo mapping since floating IP is deleted and no fixed IP is associated to it
            removeFromFloatingIpPortInfo(input.getUuid());
        }
    }

    // populate the floating to fixed ip map upon association/dissociation from fixed ip
    @Override
    public void update(InstanceIdentifier<Floatingip> identifier, Floatingip original, Floatingip update) {
        LOG.trace("Handling FloatingIptoFixedIp mapping : key: {}, original value={}, update value={}", identifier,
                original, update);
        IpAddress oldFixedIp = original.getFixedIpAddress();
        IpAddress newFixedIp = update.getFixedIpAddress();
        String floatingIp = update.getFloatingIpAddress().getIpv4Address().getValue();

        if (oldFixedIp != null && !oldFixedIp.equals(newFixedIp)) {
            clearFromFloatingIpInfo(original.getRouterId().getValue(), original.getPortId().getValue(), oldFixedIp
                    .getIpv4Address().getValue());
        }
        if (newFixedIp != null && !newFixedIp.equals(oldFixedIp)) {
            addToFloatingIpInfo(update.getRouterId().getValue(), update.getFloatingNetworkId(), update.getPortId()
                    .getValue(), newFixedIp.getIpv4Address().getValue(), floatingIp, update.getUuid());
        }
    }

    // TODO Clean up the exception handling
    @SuppressWarnings("checkstyle:IllegalCatch")
    private void addToFloatingIpInfo(String routerName, Uuid extNetworkId, String fixedNeutronPortName, String
            fixedIpAddress, String floatingIpAddress, Uuid floatingIpId) {
        RouterPortsBuilder routerPortsBuilder;
        InstanceIdentifier<RouterPorts> routerPortsIdentifier = InstanceIdentifier.builder(FloatingIpInfo.class)
                .child(RouterPorts.class, new RouterPortsKey(routerName)).build();
        try {
            Optional<RouterPorts> optionalRouterPorts =
                    SingleTransactionDataBroker.syncReadOptional(dataBroker, LogicalDatastoreType.CONFIGURATION,
                            routerPortsIdentifier);
            if (optionalRouterPorts.isPresent()) {
                LOG.debug("Updating routerPorts node {} in floatingIpInfo DS for floating IP {} on fixed "
                    + "neutron port {} : ", routerName, floatingIpAddress, fixedNeutronPortName);
                routerPortsBuilder = new RouterPortsBuilder(optionalRouterPorts.get());
            } else {
                LOG.debug("Creating new routerPorts node {} in floatingIpInfo DS for floating IP {} on fixed "
                    + "neutron port {} : ", routerName, floatingIpAddress, fixedNeutronPortName);
                routerPortsBuilder =
                    new RouterPortsBuilder().withKey(new RouterPortsKey(routerName)).setRouterId(routerName);
            }
            if (extNetworkId != null) {
                routerPortsBuilder.setExternalNetworkId(extNetworkId);
            }
            if (fixedNeutronPortName != null) {
                List<Ports> portsList = routerPortsBuilder.getPorts() != null
                        ? new ArrayList<Ports>(routerPortsBuilder.getPorts().values()) : new ArrayList<Ports>();
                PortsBuilder fixedNeutronPortBuilder = null;
                for (Ports neutronPort : portsList) {
                    if (neutronPort.getPortName().equals(fixedNeutronPortName)) {
                        fixedNeutronPortBuilder = new PortsBuilder(neutronPort);
                        break;
                    }
                }
                if (fixedNeutronPortBuilder == null) {
                    fixedNeutronPortBuilder = new PortsBuilder().withKey(new PortsKey(fixedNeutronPortName))
                            .setPortName(fixedNeutronPortName);
                }
                if (fixedIpAddress != null) {
                    List<InternalToExternalPortMap> intExtPortMapList
                            = new ArrayList<InternalToExternalPortMap>(fixedNeutronPortBuilder
                            .getInternalToExternalPortMap().values());
                    if (intExtPortMapList == null) {
                        intExtPortMapList = new ArrayList<>();
                    }
                    InternalToExternalPortMap intExtPortMap = new InternalToExternalPortMapBuilder().withKey(new
                            InternalToExternalPortMapKey(fixedIpAddress)).setInternalIp(fixedIpAddress)
                            .setExternalIp(floatingIpAddress).setExternalId(floatingIpId).build();
                    intExtPortMapList.add(intExtPortMap);
                    fixedNeutronPortBuilder.setInternalToExternalPortMap(intExtPortMapList);
                }
                portsList.add(fixedNeutronPortBuilder.build());
                routerPortsBuilder.setPorts(portsList);
            }

            try (AcquireResult lock = tryRouterLock(routerName)) {
                if (!lock.wasAcquired()) {
                    // FIXME: why do we even bother with locking if we do not honor it?!
                    logTryLockFailure(routerName);
                }

                LOG.debug("Creating/Updating routerPorts node {} in floatingIpInfo DS for floating IP {} on fixed "
                        + "neutron port {} : ", routerName, floatingIpAddress, fixedNeutronPortName);
                MDSALUtil.syncWrite(dataBroker, LogicalDatastoreType.CONFIGURATION, routerPortsIdentifier,
                    routerPortsBuilder.build());
                LOG.debug("FloatingIpInfo DS updated for floating IP {} ", floatingIpAddress);
            }
        } catch (RuntimeException | ExecutionException | InterruptedException e) {
            LOG.error("addToFloatingIpInfo failed for floating IP: {} ", floatingIpAddress, e);
        }
    }

    // TODO Clean up the exception handling
    @SuppressWarnings("checkstyle:IllegalCatch")
    private void clearFromFloatingIpInfo(String routerName, String fixedNeutronPortName, String fixedIpAddress) {
        InstanceIdentifier.InstanceIdentifierBuilder<RouterPorts> routerPortsIdentifierBuilder = InstanceIdentifier
                .builder(FloatingIpInfo.class).child(RouterPorts.class, new RouterPortsKey(routerName));
        try {
            Optional<RouterPorts> optionalRouterPorts =
                    SingleTransactionDataBroker.syncReadOptional(dataBroker, LogicalDatastoreType.CONFIGURATION,
                            routerPortsIdentifierBuilder.build());
            if (optionalRouterPorts.isPresent()) {
                RouterPorts routerPorts = optionalRouterPorts.get();
                Map<PortsKey, Ports> keyPortsMap = routerPorts.nonnullPorts();
                Map<InternalToExternalPortMapKey, InternalToExternalPortMap> keyInternalToExternalPortMapMap
                        = new HashMap<InternalToExternalPortMapKey, InternalToExternalPortMap>();
                for (Ports ports : keyPortsMap.values()) {
                    if (Objects.equals(ports.getPortName(), fixedNeutronPortName)) {
                        keyInternalToExternalPortMapMap = ports.nonnullInternalToExternalPortMap();
                        break;
                    }
                }
                if (keyInternalToExternalPortMapMap.size() == 1) {
                    removeRouterPortsOrPortsNode(routerName, routerPortsIdentifierBuilder,
                            new ArrayList<Ports>(keyPortsMap.values()), fixedNeutronPortName);
                } else {
                    for (InternalToExternalPortMap intToExtMap : keyInternalToExternalPortMapMap.values()) {
                        if (Objects.equals(intToExtMap.getInternalIp(), fixedIpAddress)) {
                            InstanceIdentifier<InternalToExternalPortMap> intExtPortMapIdentifier =
                                    routerPortsIdentifierBuilder.child(Ports
                                    .class, new PortsKey(fixedNeutronPortName)).child(InternalToExternalPortMap.class,
                                            new InternalToExternalPortMapKey(fixedIpAddress)).build();
                            try (AcquireResult lock = tryRouterLock(fixedIpAddress)) {
                                if (!lock.wasAcquired()) {
                                    // FIXME: why do we even bother with locking if we do not honor it?!
                                    logTryLockFailure(fixedIpAddress);
                                }

                                // remove particular internal-to-external-port-map
                                LOG.debug("removing particular internal-to-external-port-map {}",
                                        keyInternalToExternalPortMapMap);
                                try {
                                    MDSALUtil.syncDelete(dataBroker, LogicalDatastoreType.CONFIGURATION,
                                        intExtPortMapIdentifier);
                                } catch (Exception e) {
                                    LOG.error("Failure in deletion of internal-to-external-port-map {}",
                                            keyInternalToExternalPortMapMap, e);
                                }
                            }
                        }
                    }
                }
                LOG.debug("Deletion from FloatingIpInfo DS successful for fixedIp {} ", fixedIpAddress);
            } else {
                LOG.warn("routerPorts for router {} - fixedIp {} not found", routerName, fixedIpAddress);
            }
        } catch (RuntimeException | ExecutionException | InterruptedException e) {
            LOG.error("Failed to delete internal-to-external-port-map from FloatingIpInfo DS for fixed Ip {}",
                    fixedIpAddress, e);
        }
    }

    protected void dissociatefixedIPFromFloatingIP(String fixedNeutronPortName) {
        InstanceIdentifier.InstanceIdentifierBuilder<FloatingIpInfo> floatingIpInfoIdentifierBuilder =
                InstanceIdentifier.builder(FloatingIpInfo.class);
        try {
            Optional<FloatingIpInfo> optionalFloatingIPInfo =
                    SingleTransactionDataBroker.syncReadOptional(dataBroker, LogicalDatastoreType.CONFIGURATION,
                            floatingIpInfoIdentifierBuilder.build());
            if (optionalFloatingIPInfo.isPresent()) {
                Map<RouterPortsKey, RouterPorts> keyRouterPortsMap = optionalFloatingIPInfo.get().getRouterPorts();
                if (keyRouterPortsMap != null && !keyRouterPortsMap.isEmpty()) {
                    for (RouterPorts routerPorts : keyRouterPortsMap.values()) {
                        Map<PortsKey, Ports> keyPortsMap = routerPorts.getPorts();
                        if (keyPortsMap != null && !keyPortsMap.isEmpty()) {
                            for (Ports ports : keyPortsMap.values()) {
                                if (Objects.equals(ports.getPortName(), fixedNeutronPortName)) {
                                    String routerName = routerPorts.getRouterId();
                                    InstanceIdentifier.InstanceIdentifierBuilder<RouterPorts>
                                        routerPortsIdentifierBuilder = floatingIpInfoIdentifierBuilder
                                        .child(RouterPorts.class, new RouterPortsKey(routerName));
                                    removeRouterPortsOrPortsNode(routerName, routerPortsIdentifierBuilder,
                                            new ArrayList<Ports>(keyPortsMap.values()), fixedNeutronPortName);
                                    LOG.debug("Deletion from FloatingIpInfo DS successful for fixedIP neutron port {} ",
                                            fixedNeutronPortName);
                                    break;
                                }
                            }
                        }
                    }
                } else {
                    LOG.debug("No router present containing fixed to floating IP association(s)");
                }
            } else {
                LOG.debug("FloatingIPInfo DS empty. Hence, no router present containing fixed to floating IP "
                    + "association(s)");
            }
        } catch (ExecutionException | InterruptedException e) {
            LOG.error("Failed to dissociate fixedIP from FloatingIpInfo DS for neutron port {}",
                    fixedNeutronPortName, e);
        }
    }

    private void removeRouterPortsOrPortsNode(String routerName,
            InstanceIdentifier.InstanceIdentifierBuilder<RouterPorts> routerPortsIdentifierBuilder,
            List<Ports> portsList, String fixedNeutronPortName) {
        if (portsList.size() == 1) {
            // remove entire routerPorts node
            try (AcquireResult lock = tryRouterLock(routerName)) {
                if (!lock.wasAcquired()) {
                    // FIXME: why do we even bother with locking if we do not honor it?!
                    logTryLockFailure(routerName);
                }

                LOG.debug("removing routerPorts node: {} ", routerName);
                MDSALUtil.syncDelete(dataBroker, LogicalDatastoreType.CONFIGURATION, routerPortsIdentifierBuilder
                    .build());
            }
        } else {
            // remove entire ports node under this routerPorts node
            try (AcquireResult lock = tryRouterLock(fixedNeutronPortName)) {
                if (!lock.wasAcquired()) {
                    // FIXME: why do we even bother with locking if we do not honor it?!
                    logTryLockFailure(fixedNeutronPortName);
                }

                LOG.debug("removing ports node {} under routerPorts node {}", fixedNeutronPortName, routerName);
                MDSALUtil.syncDelete(dataBroker, LogicalDatastoreType.CONFIGURATION,
                    routerPortsIdentifierBuilder.child(Ports.class, new PortsKey(fixedNeutronPortName)).build());
            }
        }
    }

    // TODO Clean up the exception handling
    @SuppressWarnings("checkstyle:IllegalCatch")
    // updates FloatingIPPortInfo to have isFloatingIPDeleted set to true on a floating IP delete
    private void updateFloatingIpPortInfo(Uuid floatingIpId, Uuid floatingIpPortId) {
        InstanceIdentifier<FloatingIpIdToPortMapping>  id = buildfloatingIpIdToPortMappingIdentifier(floatingIpId);
        try {
            FloatingIpIdToPortMappingBuilder floatingIpIdToPortMappingBuilder = new
                    FloatingIpIdToPortMappingBuilder().setFloatingIpId(floatingIpId).setFloatingIpDeleted(true);
            LOG.debug("Updating floating IP UUID {} to Floating IP neutron port {} mapping in Floating IP"
                    + " Port Info Config DS to set isFloatingIpDeleted flag as true",
                floatingIpId.getValue(), floatingIpPortId.getValue());
            MDSALUtil.syncUpdate(dataBroker, LogicalDatastoreType.CONFIGURATION, id,
                    floatingIpIdToPortMappingBuilder.build());
        } catch (Exception e) {
            LOG.error("Updating floating IP UUID {} to Floating IP neutron port {} mapping in Floating IP"
                    + " Port Info Config DS to set isFloatingIpDeleted flag as true failed", floatingIpId.getValue(),
                    floatingIpPortId.getValue(), e);
        }
    }

    // TODO Clean up the exception handling
    @SuppressWarnings("checkstyle:IllegalCatch")
    private void removeFromFloatingIpPortInfo(Uuid floatingIpId) {
        InstanceIdentifier<FloatingIpIdToPortMapping>  id = buildfloatingIpIdToPortMappingIdentifier(floatingIpId);
        try {
            LOG.debug("Deleting floating IP UUID {} to Floating IP neutron port mapping from Floating "
                + "IP Port Info Config DS", floatingIpId.getValue());
            MDSALUtil.syncDelete(dataBroker, LogicalDatastoreType.CONFIGURATION, id);
        } catch (Exception e) {
            LOG.error("Deleting floating IP UUID {} to Floating IP neutron port mapping from Floating "
                + "IP Port Info Config DS failed", floatingIpId.getValue(), e);
        }
    }

    @CheckReturnValue
    private AcquireResult tryRouterLock(final String lockName) {
        return routerLock.tryAcquire(lockName, LOCK_WAIT_TIME, TimeUnit.SECONDS);
    }

    private static void logTryLockFailure(String lockName) {
        LOG.warn("Lock for {} was not acquired, continuing anyway", lockName, new Throwable());
    }
}