/*
 * Copyright (C) 2020 Photon Vision.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

package org.photonvision.server;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import io.javalin.websocket.*;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.*;
import org.apache.commons.lang3.tuple.Pair;
import org.msgpack.jackson.dataformat.MessagePackFactory;
import org.photonvision.common.dataflow.DataChangeDestination;
import org.photonvision.common.dataflow.DataChangeService;
import org.photonvision.common.dataflow.events.IncomingWebSocketEvent;
import org.photonvision.common.logging.LogGroup;
import org.photonvision.common.logging.Logger;
import org.photonvision.vision.pipeline.PipelineType;
import org.photonvision.vision.processes.PipelineManager;

@SuppressWarnings("rawtypes")
public class SocketHandler {

    private final Logger logger = new Logger(SocketHandler.class, LogGroup.WebServer);
    private final List<WsContext> users = new ArrayList<>();
    private final ObjectMapper objectMapper = new ObjectMapper(new MessagePackFactory());
    private final DataChangeService dcService = DataChangeService.getInstance();

    @SuppressWarnings("FieldCanBeLocal")
    private final UIOutboundSubscriber uiOutboundSubscriber = new UIOutboundSubscriber(this);

    public static class UIMap extends HashMap<String, Object> {}

    abstract static class SelectiveBroadcastPair extends Pair<UIMap, WsContext> {}

    private static class ThreadSafeSingleton {
        private static final SocketHandler INSTANCE = new SocketHandler();
    }

    public static SocketHandler getInstance() {
        return SocketHandler.ThreadSafeSingleton.INSTANCE;
    }

    private SocketHandler() {
        dcService.addSubscribers(
                uiOutboundSubscriber,
                new UIInboundSubscriber()); // Subscribe outgoing messages to the data change service
    }

    public void onConnect(WsConnectContext context) {
        context.session.setIdleTimeout(Long.MAX_VALUE); // TODO: determine better value
        var host = context.session.getRemote().getInetSocketAddress().getHostName();
        logger.info("New websocket connection from " + host);
        users.add(context);
        dcService.publishEvent(
                new IncomingWebSocketEvent<>(
                        DataChangeDestination.DCD_GENSETTINGS, "userConnected", context));
    }

    protected void onClose(WsCloseContext context) {
        var host = context.session.getRemote().getInetSocketAddress().getHostName();
        var reason = context.reason() != null ? context.reason() : "Connection closed by client";
        logger.info("Closing websocket connection from " + host + " for reason: " + reason);
        users.remove(context);
    }

    @SuppressWarnings({"unchecked"})
    public void onBinaryMessage(WsBinaryMessageContext context) {
        try {
            Map<String, Object> deserializedData =
                    objectMapper.readValue(context.data(), new TypeReference<>() {});

            // Special case the current camera index
            var camIndexValue = deserializedData.get("cameraIndex");
            Integer cameraIndex = null;
            if (camIndexValue instanceof Integer) {
                cameraIndex = (Integer) camIndexValue;
                deserializedData.remove("cameraIndex");
            }

            for (Map.Entry<String, Object> entry : deserializedData.entrySet()) {
                try {
                    var entryKey = entry.getKey();
                    var entryValue = entry.getValue();
                    var socketMessageType = SocketMessageType.fromEntryKey(entryKey);

                    logger.debug(
                            "Got WS message: ["
                                    + socketMessageType
                                    + "] ==> ["
                                    + entryKey
                                    + "], ["
                                    + entryValue
                                    + "]");

                    if (socketMessageType == null) {
                        logger.warn("Got unknown socket message type: " + entryKey);
                        continue;
                    }

                    switch (socketMessageType) {
                        case SMT_DRIVERMODE:
                            {
                                // TODO: what is this event?
                                var data = (HashMap<String, Object>) entryValue;
                                var dmExpEvent =
                                        new IncomingWebSocketEvent<Integer>(
                                                DataChangeDestination.DCD_ACTIVEMODULE, "driverExposure", data);
                                var dmBrightEvent =
                                        new IncomingWebSocketEvent<Integer>(
                                                DataChangeDestination.DCD_ACTIVEMODULE, "driverBrightness", data);
                                var dmIsDriverEvent =
                                        new IncomingWebSocketEvent<Boolean>(
                                                DataChangeDestination.DCD_ACTIVEMODULE, "isDriver", data);

                                dcService.publishEvents(dmExpEvent, dmBrightEvent, dmIsDriverEvent);
                                break;
                            }
                        case SMT_CHANGECAMERANAME:
                            {
                                var ccnEvent =
                                        new IncomingWebSocketEvent<>(
                                                DataChangeDestination.DCD_ACTIVEMODULE,
                                                "cameraNickname",
                                                (String) entryValue,
                                                cameraIndex);
                                dcService.publishEvent(ccnEvent);
                                break;
                            }
                        case SMT_CHANGEPIPELINENAME:
                            {
                                var cpnEvent =
                                        new IncomingWebSocketEvent<>(
                                                DataChangeDestination.DCD_ACTIVEMODULE,
                                                "pipelineName",
                                                (String) entryValue,
                                                cameraIndex);
                                dcService.publishEvent(cpnEvent);
                                break;
                            }
                        case SMT_ADDNEWPIPELINE:
                            {
                                //                                HashMap<String, Object> data = (HashMap<String,
                                // Object>) entryValue;
                                //                                var type = (PipelineType)
                                // data.get("pipelineType");
                                //                                var name = (String) data.get("pipelineName");
                                var type = PipelineType.Reflective;
                                var name = (String) entryValue;

                                var newPipelineEvent =
                                        new IncomingWebSocketEvent<>(
                                                DataChangeDestination.DCD_ACTIVEMODULE,
                                                "newPipelineInfo",
                                                Pair.of(name, type),
                                                cameraIndex);
                                dcService.publishEvent(newPipelineEvent);
                                break;
                            }
                        case SMT_COMMAND:
                            {
                                var cmd = SocketMessageCommandType.fromEntryKey((String) entryValue);
                                switch (cmd) {
                                    case SMCT_DELETECURRENTPIPELINE:
                                        {
                                            var deleteCurrentPipelineEvent =
                                                    new IncomingWebSocketEvent<>(
                                                            DataChangeDestination.DCD_ACTIVEMODULE,
                                                            "deleteCurrPipeline",
                                                            0,
                                                            cameraIndex);
                                            dcService.publishEvent(deleteCurrentPipelineEvent);
                                            break;
                                        }
                                    case SMCT_SAVE:
                                        {
                                            var saveEvent =
                                                    new IncomingWebSocketEvent<>(DataChangeDestination.DCD_OTHER, "save", 0);
                                            dcService.publishEvent(saveEvent);
                                            break;
                                        }
                                }
                                break;
                            }
                        case SMT_CURRENTCAMERA:
                            {
                                var changeCurrentCameraEvent =
                                        new IncomingWebSocketEvent<>(
                                                DataChangeDestination.DCD_OTHER, "changeUICamera", (Integer) entryValue);
                                dcService.publishEvent(changeCurrentCameraEvent);
                                break;
                            }
                        case SMT_CURRENTPIPELINE:
                            {
                                var changePipelineEvent =
                                        new IncomingWebSocketEvent<>(
                                                DataChangeDestination.DCD_ACTIVEMODULE,
                                                "changePipeline",
                                                (Integer) entryValue,
                                                cameraIndex);
                                dcService.publishEvent(changePipelineEvent);
                                break;
                            }
                        case SMT_ISPNPCALIBRATION:
                            {
                                var changePipelineEvent =
                                        new IncomingWebSocketEvent<>(
                                                DataChangeDestination.DCD_ACTIVEMODULE,
                                                "changePipeline",
                                                PipelineManager.CAL_3D_INDEX,
                                                cameraIndex);
                                dcService.publishEvent(changePipelineEvent);
                                break;
                            }
                        case SMT_TAKECALIBRATIONSNAPSHOT:
                            {
                                var takeCalSnapshotEvent =
                                        new IncomingWebSocketEvent<>(
                                                DataChangeDestination.DCD_ACTIVEMODULE, "takeCalSnapshot", 0, cameraIndex);
                                dcService.publishEvent(takeCalSnapshotEvent);
                                break;
                            }
                        case SMT_PIPELINESETTINGCHANGE:
                            {
                                HashMap<String, Object> data = (HashMap<String, Object>) entryValue;

                                if (data.size() >= 2) {
                                    var cameraIndex2 = (int) data.get("cameraIndex");
                                    for (var dataEntry : data.entrySet()) {
                                        if (dataEntry.getKey().equals("cameraIndex")) {
                                            continue;
                                        }
                                        var pipelineSettingChangeEvent =
                                                new IncomingWebSocketEvent(
                                                        DataChangeDestination.DCD_ACTIVEPIPELINESETTINGS,
                                                        dataEntry.getKey(),
                                                        dataEntry.getValue(),
                                                        cameraIndex2);
                                        dcService.publishEvent(pipelineSettingChangeEvent);
                                    }
                                } else {
                                    logger.warn("Unknown message for PSC: " + data.keySet().iterator().next());
                                }
                                break;
                            }
                    }
                } catch (Exception ex) {
                    logger.error("unknown booboo");
                    ex.printStackTrace();
                }
            }
        } catch (IOException e) {
            // TODO: log
            e.printStackTrace();
        }
    }

    // TODO: change to use the DataFlow system
    private void sendMessage(Object message, WsContext user) throws JsonProcessingException {
        ByteBuffer b = ByteBuffer.wrap(objectMapper.writeValueAsBytes(message));
        user.send(b);
    }

    // TODO: change to use the DataFlow system
    public void broadcastMessage(Object message, WsContext userToSkip)
            throws JsonProcessingException {
        for (WsContext user : users) {
            if (user != userToSkip) {
                sendMessage(message, user);
            }
        }
    }
}