/*
 * Copyright 2012 - 2018 Anton Tananaev (anton@traccar.org)
 *
 * 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.traccar;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.channel.Channel;
import io.netty.channel.ChannelDuplexHandler;
import io.netty.channel.ChannelHandler;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandler;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOutboundHandler;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.ChannelPromise;
import io.netty.channel.socket.DatagramChannel;
import io.netty.channel.socket.DatagramPacket;
import io.netty.handler.timeout.IdleStateHandler;
import org.traccar.events.CommandResultEventHandler;
import org.traccar.events.DriverEventHandler;
import org.traccar.events.FuelDropEventHandler;
import org.traccar.events.GeofenceEventHandler;
import org.traccar.events.IgnitionEventHandler;
import org.traccar.events.MaintenanceEventHandler;
import org.traccar.events.MotionEventHandler;
import org.traccar.events.OverspeedEventHandler;
import org.traccar.events.AlertEventHandler;
import org.traccar.helper.Log;
import org.traccar.processing.ComputedAttributesHandler;
import org.traccar.processing.CopyAttributesHandler;

import java.net.InetSocketAddress;

public abstract class BasePipelineFactory extends ChannelInitializer<Channel> {

    private final TrackerServer server;
    private int timeout;

    private FilterHandler filterHandler;
    private DistanceHandler distanceHandler;
    private EngineHoursHandler engineHoursHandler;
    private RemoteAddressHandler remoteAddressHandler;
    private MotionHandler motionHandler;
    private GeocoderHandler geocoderHandler;
    private GeolocationHandler geolocationHandler;
    private HemisphereHandler hemisphereHandler;
    private CopyAttributesHandler copyAttributesHandler;
    private ComputedAttributesHandler computedAttributesHandler;

    private CommandResultEventHandler commandResultEventHandler;
    private OverspeedEventHandler overspeedEventHandler;
    private FuelDropEventHandler fuelDropEventHandler;
    private MotionEventHandler motionEventHandler;
    private GeofenceEventHandler geofenceEventHandler;
    private AlertEventHandler alertEventHandler;
    private IgnitionEventHandler ignitionEventHandler;
    private MaintenanceEventHandler maintenanceEventHandler;
    private DriverEventHandler driverEventHandler;

    private static final class OpenChannelHandler extends ChannelDuplexHandler {

        private final TrackerServer server;

        private OpenChannelHandler(TrackerServer server) {
            this.server = server;
        }

        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            super.channelActive(ctx);
            server.getChannelGroup().add(ctx.channel());
        }

        @Override
        public void channelInactive(ChannelHandlerContext ctx) throws Exception {
            super.channelInactive(ctx);
            server.getChannelGroup().remove(ctx.channel());
        }

    }

    private static class NetworkMessageHandler extends ChannelDuplexHandler {

        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
            if (ctx.channel() instanceof DatagramChannel) {
                DatagramPacket packet = (DatagramPacket) msg;
                ctx.fireChannelRead(new NetworkMessage(packet.content(), packet.sender()));
            } else {
                ByteBuf buffer = (ByteBuf) msg;
                ctx.fireChannelRead(new NetworkMessage(buffer, ctx.channel().remoteAddress()));
            }
        }

        @Override
        public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
            NetworkMessage message = (NetworkMessage) msg;
            if (ctx.channel() instanceof DatagramChannel) {
                InetSocketAddress recipient = (InetSocketAddress) message.getRemoteAddress();
                InetSocketAddress sender = (InetSocketAddress) ctx.channel().localAddress();
                ctx.write(new DatagramPacket((ByteBuf) message.getMessage(), recipient, sender), promise);
            } else {
                ctx.write(message.getMessage(), promise);
            }
        }

    }

    private static class StandardLoggingHandler extends ChannelDuplexHandler {

        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
            log(ctx, false, msg);
            super.channelRead(ctx, msg);
        }

        @Override
        public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
            log(ctx, true, msg);
            super.write(ctx, msg, promise);
        }

        public void log(ChannelHandlerContext ctx, boolean downstream, Object o) {
            NetworkMessage networkMessage = (NetworkMessage) o;
            StringBuilder message = new StringBuilder();

            message.append("[").append(ctx.channel().id().asShortText()).append(": ");
            message.append(((InetSocketAddress) ctx.channel().localAddress()).getPort());
            if (downstream) {
                message.append(" > ");
            } else {
                message.append(" < ");
            }

            if (networkMessage.getRemoteAddress() != null) {
                message.append(((InetSocketAddress) networkMessage.getRemoteAddress()).getHostString());
            } else {
                message.append("null");
            }
            message.append("]");

            message.append(" HEX: ");
            message.append(ByteBufUtil.hexDump((ByteBuf) networkMessage.getMessage()));

            Log.debug(message.toString());
        }

    }

    public BasePipelineFactory(TrackerServer server, String protocol) {
        this.server = server;

        timeout = Context.getConfig().getInteger(protocol + ".timeout");
        if (timeout == 0) {
            timeout = Context.getConfig().getInteger(protocol + ".resetDelay"); // temporary
            if (timeout == 0) {
                timeout = Context.getConfig().getInteger("server.timeout");
            }
        }

        distanceHandler = new DistanceHandler(
                Context.getConfig().getBoolean("coordinates.filter"),
                Context.getConfig().getInteger("coordinates.minError"),
                Context.getConfig().getInteger("coordinates.maxError"));

        if (Context.getConfig().getBoolean("processing.remoteAddress.enable")) {
            remoteAddressHandler = new RemoteAddressHandler();
        }

        if (Context.getConfig().getBoolean("filter.enable")) {
            filterHandler = new FilterHandler();
        }

        if (Context.getGeocoder() != null && !Context.getConfig().getBoolean("geocoder.ignorePositions")) {
            geocoderHandler = new GeocoderHandler(
                    Context.getGeocoder(),
                    Context.getConfig().getBoolean("geocoder.processInvalidPositions"));
        }

        if (Context.getGeolocationProvider() != null) {
            geolocationHandler = new GeolocationHandler(
                    Context.getGeolocationProvider(),
                    Context.getConfig().getBoolean("geolocation.processInvalidPositions"));
        }

        motionHandler = new MotionHandler(Context.getTripsConfig().getSpeedThreshold());

        if (Context.getConfig().getBoolean("processing.engineHours.enable")) {
            engineHoursHandler = new EngineHoursHandler();
        }

        if (Context.getConfig().hasKey("location.latitudeHemisphere")
                || Context.getConfig().hasKey("location.longitudeHemisphere")) {
            hemisphereHandler = new HemisphereHandler();
        }

        if (Context.getConfig().getBoolean("processing.copyAttributes.enable")) {
            copyAttributesHandler = new CopyAttributesHandler();
        }

        if (Context.getConfig().getBoolean("processing.computedAttributes.enable")) {
            computedAttributesHandler = new ComputedAttributesHandler();
        }

        if (Context.getConfig().getBoolean("event.enable")) {
            commandResultEventHandler = new CommandResultEventHandler();
            overspeedEventHandler = Context.getOverspeedEventHandler();
            fuelDropEventHandler = new FuelDropEventHandler();
            motionEventHandler = Context.getMotionEventHandler();
            geofenceEventHandler = new GeofenceEventHandler();
            alertEventHandler = new AlertEventHandler();
            ignitionEventHandler = new IgnitionEventHandler();
            maintenanceEventHandler = new MaintenanceEventHandler();
            driverEventHandler = new DriverEventHandler();
        }
    }

    protected abstract void addProtocolHandlers(PipelineBuilder pipeline);

    @Override
    protected void initChannel(Channel channel) throws Exception {
        final ChannelPipeline pipeline = channel.pipeline();
        if (timeout > 0 && !server.isDatagram()) {
            pipeline.addLast("idleHandler", new IdleStateHandler(timeout, 0, 0));
        }
        pipeline.addLast("openHandler", new OpenChannelHandler(server));
        pipeline.addLast("messageHandler", new NetworkMessageHandler());
        if (Context.isLoggerEnabled()) {
            pipeline.addLast("logger", new StandardLoggingHandler());
        }

        addProtocolHandlers(new PipelineBuilder() {
            @Override
            public void addLast(String name, ChannelHandler handler) {
                if (!(handler instanceof BaseProtocolDecoder || handler instanceof BaseProtocolEncoder)) {
                    if (handler instanceof ChannelInboundHandler) {
                        handler = new WrapperInboundHandler((ChannelInboundHandler) handler);
                    } else {
                        handler = new WrapperOutboundHandler((ChannelOutboundHandler) handler);
                    }
                }
                pipeline.addLast(name, handler);
            }
        });

        if (geolocationHandler != null) {
            pipeline.addLast("location", geolocationHandler);
        }
        if (hemisphereHandler != null) {
            pipeline.addLast("hemisphere", hemisphereHandler);
        }

        if (distanceHandler != null) {
            pipeline.addLast("distance", distanceHandler);
        }

        if (remoteAddressHandler != null) {
            pipeline.addLast("remoteAddress", remoteAddressHandler);
        }

        addDynamicHandlers(pipeline);

        if (filterHandler != null) {
            pipeline.addLast("filter", filterHandler);
        }

        if (geocoderHandler != null) {
            pipeline.addLast("geocoder", geocoderHandler);
        }

        if (motionHandler != null) {
            pipeline.addLast("motion", motionHandler);
        }

        if (engineHoursHandler != null) {
            pipeline.addLast("engineHours", engineHoursHandler);
        }

        if (copyAttributesHandler != null) {
            pipeline.addLast("copyAttributes", copyAttributesHandler);
        }

        if (computedAttributesHandler != null) {
            pipeline.addLast("computedAttributes", computedAttributesHandler);
        }

        if (Context.getDataManager() != null) {
            pipeline.addLast("dataHandler", new DefaultDataHandler());
        }

        if (Context.getConfig().getBoolean("forward.enable")) {
            pipeline.addLast("webHandler", new WebDataHandler(Context.getConfig().getString("forward.url"),
                    Context.getConfig().getBoolean("forward.json")));
        }

        if (commandResultEventHandler != null) {
            pipeline.addLast("CommandResultEventHandler", commandResultEventHandler);
        }

        if (overspeedEventHandler != null) {
            pipeline.addLast("OverspeedEventHandler", overspeedEventHandler);
        }

        if (fuelDropEventHandler != null) {
            pipeline.addLast("FuelDropEventHandler", fuelDropEventHandler);
        }

        if (motionEventHandler != null) {
            pipeline.addLast("MotionEventHandler", motionEventHandler);
        }

        if (geofenceEventHandler != null) {
            pipeline.addLast("GeofenceEventHandler", geofenceEventHandler);
        }

        if (alertEventHandler != null) {
            pipeline.addLast("AlertEventHandler", alertEventHandler);
        }

        if (ignitionEventHandler != null) {
            pipeline.addLast("IgnitionEventHandler", ignitionEventHandler);
        }

        if (maintenanceEventHandler != null) {
            pipeline.addLast("MaintenanceEventHandler", maintenanceEventHandler);
        }

        if (driverEventHandler != null) {
            pipeline.addLast("DriverEventHandler", driverEventHandler);
        }

        pipeline.addLast("mainHandler", new MainEventHandler());
    }

    private void addDynamicHandlers(ChannelPipeline pipeline) {
        if (Context.getConfig().hasKey("extra.handlers")) {
            String[] handlers = Context.getConfig().getString("extra.handlers").split(",");
            for (int i = 0; i < handlers.length; i++) {
                try {
                    pipeline.addLast("extraHandler." + i, (ChannelHandler) Class.forName(handlers[i]).newInstance());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException error) {
                    Log.warning(error);
                }
            }
        }
    }

}