/*
 * Copyright (c) 2014, 2015 Red Hat, 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.ovsdb.openstack.netvirt.providers.openflow13.services;

import java.math.BigInteger;
import java.net.InetAddress;
import java.net.Inet6Address;
import java.net.UnknownHostException;
import java.util.List;

import org.opendaylight.ovsdb.openstack.netvirt.api.Action;
import org.opendaylight.ovsdb.openstack.netvirt.api.InboundNatProvider;
import org.opendaylight.ovsdb.openstack.netvirt.api.Status;
import org.opendaylight.ovsdb.openstack.netvirt.api.StatusCode;
import org.opendaylight.ovsdb.openstack.netvirt.providers.ConfigInterface;
import org.opendaylight.ovsdb.openstack.netvirt.providers.openflow13.AbstractServiceInstance;
import org.opendaylight.ovsdb.openstack.netvirt.providers.openflow13.Service;
import org.opendaylight.ovsdb.utils.mdsal.openflow.ActionUtils;
import org.opendaylight.ovsdb.utils.mdsal.openflow.FlowUtils;
import org.opendaylight.ovsdb.utils.mdsal.openflow.InstructionUtils;
import org.opendaylight.ovsdb.utils.mdsal.openflow.MatchUtils;
import org.opendaylight.yang.gen.v1.urn.ietf.params.xml.ns.yang.ietf.inet.types.rev100924.Ipv4Prefix;
import org.opendaylight.yang.gen.v1.urn.opendaylight.action.types.rev131112.action.list.ActionBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.inventory.rev130819.tables.table.FlowBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.flow.InstructionsBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.flow.MatchBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.list.Instruction;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.list.InstructionBuilder;
import org.opendaylight.yang.gen.v1.urn.opendaylight.flow.types.rev131026.instruction.list.InstructionKey;
import org.opendaylight.yang.gen.v1.urn.opendaylight.inventory.rev130819.nodes.NodeBuilder;

import com.google.common.collect.Lists;
import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowjava.nx.match.rev140421.NxmNxReg;
import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowjava.nx.match.rev140421.NxmNxReg3;
import org.opendaylight.yang.gen.v1.urn.opendaylight.openflowplugin.extension.nicira.action.rev140714.dst.choice.grouping.dst.choice.DstNxRegCaseBuilder;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class InboundNatService extends AbstractServiceInstance implements ConfigInterface, InboundNatProvider {
    private static final Logger LOG = LoggerFactory.getLogger(InboundNatService.class);
    public static final Class<? extends NxmNxReg> REG_FIELD = NxmNxReg3.class;

    public InboundNatService() {
        super(Service.INBOUND_NAT);
    }

    public InboundNatService(Service service) {
        super(service);
    }

    @Override
    public Status programIpRewriteRule(Long dpid, Long inPort, String destSegId, InetAddress matchAddress,
                                       InetAddress rewriteAddress, Action action) {
        NodeBuilder nodeBuilder = FlowUtils.createNodeBuilder(dpid);
        FlowBuilder flowBuilder = new FlowBuilder();
        String flowName = "InboundNAT_" + inPort + "_" + destSegId + "_" + matchAddress.getHostAddress();
        FlowUtils.initFlowBuilder(flowBuilder, flowName, getTable()).setPriority(1024);

        MatchBuilder matchBuilder = new MatchBuilder();
        MatchUtils.createInPortMatch(matchBuilder, dpid, inPort);
        MatchUtils.createDstL3IPv4Match(matchBuilder,
                MatchUtils.iPv4PrefixFromIPv4Address(matchAddress.getHostAddress()));
        flowBuilder.setMatch(matchBuilder.build());

        if (action.equals(Action.ADD)) {
            // Instructions List Stores Individual Instructions
            InstructionsBuilder isb = new InstructionsBuilder();
            List<Instruction> instructions = Lists.newArrayList();
            InstructionBuilder ib = new InstructionBuilder();

            // Set register to indicate that rewrite took place
            ActionBuilder actionBuilder = new ActionBuilder();
            actionBuilder.setAction(ActionUtils.nxLoadRegAction(new DstNxRegCaseBuilder().setNxReg(REG_FIELD).build(),
                    new BigInteger(destSegId)));

            // Set Dest IP address and set REG_FIELD
            InstructionUtils.createNwDstInstructions(ib,
                    MatchUtils.iPv4PrefixFromIPv4Address(rewriteAddress.getHostAddress()), actionBuilder);
            ib.setOrder(0);
            ib.setKey(new InstructionKey(0));
            instructions.add(ib.build());

            // Goto Next Table
            ib = getMutablePipelineInstructionBuilder();
            ib.setOrder(1);
            ib.setKey(new InstructionKey(1));
            instructions.add(ib.build());

            flowBuilder.setInstructions(isb.setInstruction(instructions).build());

            writeFlow(flowBuilder, nodeBuilder);
        } else {
            removeFlow(flowBuilder, nodeBuilder);
        }

        // ToDo: WriteFlow/RemoveFlow should return something we can use to check success
        return new Status(StatusCode.SUCCESS);
    }

    @Override
    public Status programIpRewriteExclusion(Long dpid, String segmentationId, String excludedCidr,
                                            Action action) {
        String ipAddress = excludedCidr.substring(0, excludedCidr.indexOf("/"));
        InetAddress inetAddress;
        try {
            inetAddress = InetAddress.getByName(ipAddress);
        } catch (UnknownHostException e) {
            return new Status(StatusCode.BADREQUEST);
        }
        if (inetAddress instanceof Inet6Address) {
            // WORKAROUND: For now ipv6 is not supported
            // TODO: implement ipv6 cidr case
            LOG.debug("ipv6 cidr is not implemented yet. cidr {}",
                    excludedCidr);
            return new Status(StatusCode.NOTIMPLEMENTED);
        }

        NodeBuilder nodeBuilder = FlowUtils.createNodeBuilder(dpid);
        FlowBuilder flowBuilder = new FlowBuilder();
        String flowName = "InboundNATExclusion_" + segmentationId + "_" + excludedCidr;
        FlowUtils.initFlowBuilder(flowBuilder, flowName, getTable()).setPriority(1024);

        MatchBuilder matchBuilder = new MatchBuilder();
        MatchUtils.createTunnelIDMatch(matchBuilder, new BigInteger(segmentationId));

        MatchUtils.createDstL3IPv4Match(matchBuilder, new Ipv4Prefix(excludedCidr));
        flowBuilder.setMatch(matchBuilder.build());

        if (action.equals(Action.ADD)) {
            // Instructions List Stores Individual Instructions
            InstructionsBuilder isb = new InstructionsBuilder();
            List<Instruction> instructions = Lists.newArrayList();
            InstructionBuilder ib;

            // Goto Next Table
            ib = getMutablePipelineInstructionBuilder();
            ib.setOrder(0);
            ib.setKey(new InstructionKey(0));
            instructions.add(ib.build());

            flowBuilder.setInstructions(isb.setInstruction(instructions).build());

            writeFlow(flowBuilder, nodeBuilder);
        } else {
            removeFlow(flowBuilder, nodeBuilder);
        }

        // ToDo: WriteFlow/RemoveFlow should return something we can use to check success
        return new Status(StatusCode.SUCCESS);
    }

    @Override
    public void setDependencies(BundleContext bundleContext, ServiceReference serviceReference) {
        super.setDependencies(bundleContext.getServiceReference(InboundNatProvider.class.getName()), this);
    }

    @Override
    public void setDependencies(Object impl) {}
}