/*
 * 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
 */
/**
 * Generated file

 * Generated from: yang module name: bgp-rib-impl  yang module local name: bgp-peer
 * Generated by: org.opendaylight.controller.config.yangjmxgenerator.plugin.JMXGenerator
 * Generated at: Sat Jan 25 11:00:14 CET 2014
 *
 * Do not modify this file unless it is present under src/main directory
 */
package org.opendaylight.controller.config.yang.bgp.rib.impl;

import com.google.common.base.Charsets;
import com.google.common.collect.Lists;
import com.google.common.net.InetAddresses;
import io.netty.util.concurrent.Future;
import java.net.InetSocketAddress;
import java.util.List;
import org.opendaylight.bgpcep.tcpmd5.KeyMapping;
import org.opendaylight.controller.config.api.JmxAttributeValidationException;
import org.opendaylight.protocol.bgp.rib.impl.BGPPeer;
import org.opendaylight.protocol.bgp.rib.impl.StrictBGPPeerRegistry;
import org.opendaylight.protocol.bgp.rib.impl.spi.BGPPeerRegistry;
import org.opendaylight.protocol.bgp.rib.impl.spi.BGPSessionPreferences;
import org.opendaylight.protocol.bgp.rib.impl.spi.RIB;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.AsNumber;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.IpAddress;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.BgpParameters;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.BgpParametersBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.bgp.parameters.c.parameters.As4BytesCaseBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.message.rev130919.open.bgp.parameters.c.parameters.as4.bytes._case.As4BytesCapabilityBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.BgpTableType;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.MultiprotocolCaseBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.params.xml.ns.yang.bgp.multiprotocol.rev130919.open.bgp.parameters.c.parameters.multiprotocol._case.MultiprotocolCapabilityBuilder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 */
public final class BGPPeerModule extends org.opendaylight.controller.config.yang.bgp.rib.impl.AbstractBGPPeerModule {
    private static final Logger LOG = LoggerFactory.getLogger(BGPPeerModule.class);

    public BGPPeerModule(final org.opendaylight.controller.config.api.ModuleIdentifier identifier,
        final org.opendaylight.controller.config.api.DependencyResolver dependencyResolver) {
        super(identifier, dependencyResolver);
    }

    public BGPPeerModule(final org.opendaylight.controller.config.api.ModuleIdentifier identifier,
        final org.opendaylight.controller.config.api.DependencyResolver dependencyResolver, final BGPPeerModule oldModule,
        final java.lang.AutoCloseable oldInstance) {

        super(identifier, dependencyResolver, oldModule, oldInstance);
    }

    @Override
    protected void customValidation() {
        JmxAttributeValidationException.checkNotNull(getHost(), "value is not set.", hostJmxAttribute);
        JmxAttributeValidationException.checkNotNull(getPort(), "value is not set.", portJmxAttribute);

        if (getPassword() != null) {
            /*
             *  This is a nasty hack, but we don't have another clean solution. We cannot allow
             *  password being set if the injected dispatcher does not have the optional
             *  md5-server-channel-factory set.
             *
             *  FIXME: this is a use case for Module interfaces, e.g. RibImplModule
             *         should something like isMd5ServerSupported()
             */

            final RIBImplModuleMXBean ribProxy = this.dependencyResolver.newMXBeanProxy(getRib(), RIBImplModuleMXBean.class);
            final BGPDispatcherImplModuleMXBean bgpDispatcherProxy = this.dependencyResolver.newMXBeanProxy(
                ribProxy.getBgpDispatcher(), BGPDispatcherImplModuleMXBean.class);
            final boolean isMd5Supported = bgpDispatcherProxy.getMd5ChannelFactory() != null;

            JmxAttributeValidationException.checkCondition(isMd5Supported,
                "Underlying dispatcher does not support MD5 clients", passwordJmxAttribute);

        }
    }

    private InetSocketAddress createAddress() {
        final IpAddress ip = getHost();
        if (ip.getIpv4Address() != null) {
            return new InetSocketAddress(InetAddresses.forString(ip.getIpv4Address().getValue()), getPort().getValue());
        } else if (ip.getIpv6Address() != null) {
            return new InetSocketAddress(InetAddresses.forString(ip.getIpv6Address().getValue()), getPort().getValue());
        } else {
            throw new IllegalStateException("Failed to handle host " + getHost());
        }
    }

    @Override
    public java.lang.AutoCloseable createInstance() {
        final RIB r = getRibDependency();

        final List<BgpParameters> tlvs = getTlvs(r);
        final AsNumber remoteAs = getAsOrDefault(r);
        final String password = getPasswordOrNull();

        final BGPSessionPreferences prefs = new BGPSessionPreferences(r.getLocalAs(), getHoldtimer(), r.getBgpIdentifier(), tlvs);
        final BGPPeer bgpClientPeer = new BGPPeer(peerName(getHostWithoutValue()), r);

        getPeerRegistryBackwards().addPeer(getHostWithoutValue(), bgpClientPeer, prefs);

        final CloseableNoEx peerCloseable = new CloseableNoEx() {
            @Override
            public void close() {
                bgpClientPeer.close();
                getPeerRegistryBackwards().removePeer(getHostWithoutValue());
            }
        };

        // Initiate connection
        if(getInitiateConnection()) {
            final Future<Void> cf = initiateConnection(createAddress(), password, remoteAs, getPeerRegistryBackwards());
            return new CloseableNoEx() {
                @Override
                public void close() {
                    cf.cancel(true);
                    peerCloseable.close();
                }
            };
        } else {
            return peerCloseable;
        }
    }

    private interface CloseableNoEx extends AutoCloseable {
        @Override
        void close();
    }

    private String getPasswordOrNull() {
        final String password;
        if (getPassword() != null) {
            password = getPassword().getValue();
        } else {
            password = null;
        }
        return password;
    }

    private AsNumber getAsOrDefault(final RIB r) {
        // Remote AS number defaults to our local AS
        final AsNumber remoteAs;
        if (getRemoteAs() != null) {
            remoteAs = new AsNumber(getRemoteAs());
        } else {
            remoteAs = r.getLocalAs();
        }
        return remoteAs;
    }

    private List<BgpParameters> getTlvs(final RIB r) {
        final List<BgpParameters> tlvs = Lists.newArrayList();
        tlvs.add(new BgpParametersBuilder().setCParameters(
            new As4BytesCaseBuilder().setAs4BytesCapability(new As4BytesCapabilityBuilder().setAsNumber(r.getLocalAs()).build()).build()).build());

        for (final BgpTableType t : getAdvertizedTableDependency()) {
            if (!r.getLocalTables().contains(t)) {
                LOG.info("RIB instance does not list {} in its local tables. Incoming data will be dropped.", t);
            }

            tlvs.add(new BgpParametersBuilder().setCParameters(
                new MultiprotocolCaseBuilder().setMultiprotocolCapability(new MultiprotocolCapabilityBuilder(t).build()).build()).build());
        }
        return tlvs;
    }

    public IpAddress getHostWithoutValue() {
        // FIXME we need to remove field "value" from IpAddress since equals does not work as expected when value being present
        // Remove after this bug is fixed https://bugs.opendaylight.org/show_bug.cgi?id=1276
        final IpAddress host = super.getHost();
        if(host.getIpv4Address() != null) {
            return new IpAddress(host.getIpv4Address());
        } else if(host.getIpv6Address() != null){
            return new IpAddress(host.getIpv6Address());
        }

        throw new IllegalArgumentException("Unexpected host " + host);
    }

    private io.netty.util.concurrent.Future<Void> initiateConnection(final InetSocketAddress address, final String password, final AsNumber remoteAs, final BGPPeerRegistry registry) {
        final KeyMapping keys;
        if (password != null) {
            keys = new KeyMapping();
            keys.put(address.getAddress(), password.getBytes(Charsets.US_ASCII));
        } else {
            keys = null;
        }

        final RIB rib = getRibDependency();
        return rib.getDispatcher().createReconnectingClient(address, remoteAs, registry, rib.getTcpStrategyFactory(),
            rib.getSessionStrategyFactory(), keys);
    }

    private BGPPeerRegistry getPeerRegistryBackwards() {
        return getPeerRegistry() == null ? StrictBGPPeerRegistry.GLOBAL : getPeerRegistryDependency();
    }

    private static String peerName(final IpAddress host) {
        if (host.getIpv4Address() != null) {
            return host.getIpv4Address().getValue();
        }
        if (host.getIpv6Address() != null) {
            return host.getIpv6Address().getValue();
        }

        return null;
    }

}