/*
 * Copyright 2015-present Open Networking Laboratory
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.onosproject.pcep.controller.impl;

import java.net.InetSocketAddress;
import java.net.SocketAddress;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.RejectedExecutionException;

import org.jboss.netty.channel.Channel;
import org.onlab.packet.IpAddress;
import org.onosproject.pcep.controller.ClientCapability;
import org.onosproject.pcep.controller.LspKey;
import org.onosproject.pcep.controller.PccId;
import org.onosproject.pcep.controller.PcepClient;
import org.onosproject.pcep.controller.PcepPacketStats;
import org.onosproject.pcep.controller.PcepSyncStatus;
import org.onosproject.pcep.controller.driver.PcepAgent;
import org.onosproject.pcep.controller.driver.PcepClientDriver;
import org.onosproject.pcepio.protocol.PcepFactories;
import org.onosproject.pcepio.protocol.PcepFactory;
import org.onosproject.pcepio.protocol.PcepMessage;
import org.onosproject.pcepio.protocol.PcepStateReport;
import org.onosproject.pcepio.protocol.PcepVersion;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.MoreObjects;

/**
 * An abstract representation of an OpenFlow switch. Can be extended by others
 * to serve as a base for their vendor specific representation of a switch.
 */
public class PcepClientImpl implements PcepClientDriver {

    protected final Logger log = LoggerFactory.getLogger(PcepClientImpl.class);

    private static final String SHUTDOWN_MSG = "Worker has already been shutdown";

    private Channel channel;
    protected String channelId;

    private boolean connected;
    protected boolean startDriverHandshakeCalled;
    protected boolean isHandShakeComplete;
    private PcepSyncStatus lspDbSyncStatus;
    private PcepSyncStatus labelDbSyncStatus;
    private PccId pccId;
    private PcepAgent agent;

    private ClientCapability capability;
    private PcepVersion pcepVersion;
    private byte keepAliveTime;
    private byte deadTime;
    private byte sessionId;
    private PcepPacketStatsImpl pktStats;
    private Map<LspKey, Boolean> lspDelegationInfo = new HashMap<>();
    private Map<PccId, List<PcepStateReport>> syncRptCache = new HashMap<>();

    @Override
    public void init(PccId pccId, PcepVersion pcepVersion, PcepPacketStats pktStats) {
        this.pccId = pccId;
        this.pcepVersion = pcepVersion;
        this.pktStats = (PcepPacketStatsImpl) pktStats;
    }

    @Override
    public final void disconnectClient() {
        this.channel.close();
    }

    @Override
    public void setCapability(ClientCapability capability) {
        this.capability = capability;
    }

    @Override
    public ClientCapability capability() {
        return capability;
    }

    @Override
    public final void sendMessage(PcepMessage m) {
        log.debug("Sending message to {}", channel.getRemoteAddress());
        try {
            channel.write(Collections.singletonList(m));
            this.pktStats.addOutPacket();
        } catch (RejectedExecutionException e) {
            log.warn(e.getMessage());
            if (!e.getMessage().contains(SHUTDOWN_MSG)) {
                throw e;
            }
        }
    }

    @Override
    public final void sendMessage(List<PcepMessage> msgs) {
        try {
            channel.write(msgs);
            this.pktStats.addOutPacket(msgs.size());
        } catch (RejectedExecutionException e) {
            log.warn(e.getMessage());
            if (!e.getMessage().contains(SHUTDOWN_MSG)) {
                throw e;
            }
        }
    }

    @Override
    public final boolean isConnected() {
        return this.connected;
    }

    @Override
    public final void setConnected(boolean connected) {
        this.connected = connected;
    }

    @Override
    public final void setChannel(Channel channel) {
        this.channel = channel;
        final SocketAddress address = channel.getRemoteAddress();
        if (address instanceof InetSocketAddress) {
            final InetSocketAddress inetAddress = (InetSocketAddress) address;
            final IpAddress ipAddress = IpAddress.valueOf(inetAddress.getAddress());
            if (ipAddress.isIp4()) {
                channelId = ipAddress.toString() + ':' + inetAddress.getPort();
            } else {
                channelId = '[' + ipAddress.toString() + "]:" + inetAddress.getPort();
            }
        }
    }

    @Override
    public String channelId() {
        return channelId;
    }

    @Override
    public final PccId getPccId() {
        return this.pccId;
    }

    @Override
    public final String getStringId() {
        return this.pccId.toString();
    }

    @Override
    public final void setPcVersion(PcepVersion pcepVersion) {
        this.pcepVersion = pcepVersion;
    }

    @Override
    public void setPcKeepAliveTime(byte keepAliveTime) {
        this.keepAliveTime = keepAliveTime;
    }

    @Override
    public void setPcDeadTime(byte deadTime) {
        this.deadTime = deadTime;
    }

    @Override
    public void setPcSessionId(byte sessionId) {
        this.sessionId = sessionId;
    }

    @Override
    public void setLspDbSyncStatus(PcepSyncStatus syncStatus) {
        log.debug("LSP DB sync status set from {} to {}", this.lspDbSyncStatus, syncStatus);
        this.lspDbSyncStatus = syncStatus;
    }

    @Override
    public PcepSyncStatus lspDbSyncStatus() {
        return lspDbSyncStatus;
    }

    @Override
    public void setLabelDbSyncStatus(PcepSyncStatus syncStatus) {

        PcepSyncStatus syncOldStatus = labelDbSyncStatus();
        this.labelDbSyncStatus = syncStatus;
        log.debug("Label DB sync status set from {} to {}", syncOldStatus, syncStatus);
        if ((syncOldStatus == PcepSyncStatus.IN_SYNC) && (syncStatus == PcepSyncStatus.SYNCED)) {
            // Perform end of LSP DB sync actions.
            this.agent.analyzeSyncMsgList(pccId);
        }
    }

    @Override
    public PcepSyncStatus labelDbSyncStatus() {
        return labelDbSyncStatus;
    }

    @Override
    public final void handleMessage(PcepMessage m) {
        this.pktStats.addInPacket();
        this.agent.processPcepMessage(pccId, m);
    }

    @Override
    public void addNode(PcepClient pc) {
        this.agent.addNode(pc);
    }

    @Override
    public void deleteNode(PccId pccId) {
        this.agent.deleteNode(pccId);
    }

    @Override
    public final boolean connectClient() {
        return this.agent.addConnectedClient(pccId, this);
    }

    @Override
    public final void removeConnectedClient() {
        this.agent.removeConnectedClient(pccId);
    }

    @Override
    public PcepFactory factory() {
        return PcepFactories.getFactory(pcepVersion);
    }

    @Override
    public boolean isHandshakeComplete() {
        return isHandShakeComplete;
    }

    @Override
    public final void setAgent(PcepAgent ag) {
        if (this.agent == null) {
            this.agent = ag;
        }
    }

    @Override
    public void setLspAndDelegationInfo(LspKey lspKey, boolean dFlag) {
        lspDelegationInfo.put(lspKey, dFlag);
    }

    @Override
    public Boolean delegationInfo(LspKey lspKey) {
        return lspDelegationInfo.get(lspKey);
    }

    @Override
    public void initializeSyncMsgList(PccId pccId) {
        List<PcepStateReport> rptMsgList = new LinkedList<>();
        syncRptCache.put(pccId, rptMsgList);
    }

    @Override
    public List<PcepStateReport> getSyncMsgList(PccId pccId) {
        return syncRptCache.get(pccId);
    }

    @Override
    public void removeSyncMsgList(PccId pccId) {
        syncRptCache.remove(pccId);
    }

    @Override
    public void addSyncMsgToList(PccId pccId, PcepStateReport rptMsg) {
        List<PcepStateReport> rptMsgList = syncRptCache.get(pccId);
        rptMsgList.add(rptMsg);
        syncRptCache.put(pccId, rptMsgList);
    }

    @Override
    public boolean isOptical() {
        return false;
    }

    @Override
    public String toString() {
        return MoreObjects.toStringHelper(getClass())
                .add("channel", channelId())
                .add("pccId", getPccId())
                .toString();
    }
}