/*!
 *
 * Copyright (c) 2024-2026 Diality Inc. - All Rights Reserved.
 * \copyright
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
 *
 * \file    CloudConnectController.cpp
 * \author  (original)  Stephen Quong
 * \date    (original)  24-May-2026
 *
 */
#include <QDebug>
#include <QFile>
#include <QString>

#include "CloudConnectController.h"
#include "LeahiMsgProtoUtils.h"

/*!
 * \brief   CloudConnectController::CloudConnectController
 * \details Constructor. Starts the CAN interface and wires the frame→dispatcher→
 *          completed-message pipeline.
 * \param   configPath      - path to the settings file
 * \param   msgHandlingPath - path to the message handling INI
 * \param   parent          - optional QObject parent
 */
CloudConnectController::CloudConnectController(const QString &configPath, const QString &msgHandlingPath, QObject *parent) :
    QObject(parent),
    _settings(configPath, QSettings::IniFormat),
    _canInterface(),
    _canThread(this),
    _dispatcher(this),
    _appServer(this)
{
    loadMsgHandling(msgHandlingPath);

    _canInterface.init(_canThread);
    connect(&_canInterface, &Can::CanInterface::didFrameReceive, this, &CloudConnectController::onFrameReceive);
    connect(&_dispatcher, &Can::MessageDispatcher::didActionReceive, this, &CloudConnectController::onMessageReceive);
    connect(&_agentInterface, &CloudConnectClient::didDisconnect, this, &CloudConnectController::onAgentDisconnect);
}

/*!
 * \brief   CloudConnectController::~CloudConnectController
 * \details Destructor. Stops and joins the CAN and Agent worker threads.
 */
CloudConnectController::~CloudConnectController()
{
    _canThread.quit();
    _canThread.wait();

    _agentThread.quit();
    _agentThread.wait();
}

/*!
 * \brief   CloudConnectController::connectToAgent
 * \details Initialises the CloudConnectClient using the socket path and reconnect
 *          interval from the settings file.
 */
void CloudConnectController::connectToAgent()
{
    const QString socketPath = _settings.value("Socket/AgentSocketName", "/tmp/cloudconnect_agent.sock").toString();
    const int reconnectIntervalMs = _settings.value("Socket/ReconnectIntervalMs", 5000).toInt();
    _agentInterface.init(socketPath, reconnectIntervalMs, _agentThread);
}

/*!
 * \brief   CloudConnectController::listenForApp
 * \details Starts the local-socket server that the Luis application connects to,
 *          using the app socket path from the settings file.
 * \return  true if the server bound successfully, false otherwise.
 */
bool CloudConnectController::listenForApp()
{
    const QString appSocketPath = _settings.value("Socket/AppSocketName", "/tmp/cloudconnect_app.sock").toString();
    return _appServer.listen(appSocketPath);
}

/*!
 * \brief   CloudConnectController::loadMsgHandling
 * \details Parses message handling INI and populates _msgHandling.
 * \note    Unknown msg action values default to Drop; unknown topic strings default to ClinicalData.
 * \param   msgHandlingPath - path to the message handling INI file
 */
void CloudConnectController::loadMsgHandling(const QString &msgHandlingPath)
{
    static const QHash<QString, MsgAction> actionMap = {
        { QStringLiteral("SendAlways"), MsgAction::SendAlways },
        { QStringLiteral("SendDelta"),  MsgAction::SendDelta  },
        { QStringLiteral("Drop"),       MsgAction::Drop       },
    };
    static const QHash<QString, CloudConnectFrame::Type> topicMap = {
        { QStringLiteral("HighPriority"),       CloudConnectFrame::Type::HighPriority       },
        { QStringLiteral("NormalPriority"),     CloudConnectFrame::Type::NormalPriority     },
        { QStringLiteral("DeviceLogFile"),      CloudConnectFrame::Type::DeviceLogFile      },
        { QStringLiteral("TreatmentLogFile"),   CloudConnectFrame::Type::TreatmentLogFile   },
        { QStringLiteral("CloudSyncLogFile"),   CloudConnectFrame::Type::CloudSyncLogFile   },
    };

    if (! QFile::exists(msgHandlingPath)) {
        qWarning().noquote() << "CloudConnect: handling INI" << msgHandlingPath << "does not exist";
        return;
    }

    QSettings msgHandlingIni(msgHandlingPath, QSettings::IniFormat);
    if (msgHandlingIni.status() != QSettings::NoError) {
        qWarning().noquote() << "CloudConnect: could not read message handling INI" << msgHandlingPath << "— all messages will be dropped";
        return;
    }

    int msgCount = 0;
    for (const QString &group : msgHandlingIni.childGroups()) {
        bool ok = false;
        const Can::MsgId msgId = static_cast<Can::MsgId>(group.toUInt(&ok, 16));
        if (!ok) {
            qWarning().noquote() << QString("CloudConnect: could not convert group \"%1\" to MsgId").arg(group);
            continue;
        }

        msgHandlingIni.beginGroup(group);
        const QString msgIdStr  = msgHandlingIni.value(QStringLiteral("msg_id")).toString();
        const QString actionStr = msgHandlingIni.value(QStringLiteral("action")).toString().trimmed();
        const QString topicStr  = msgHandlingIni.value(QStringLiteral("topic")).toString().trimmed();
        qInfo().noquote() << QString("%1 (0x%2): action=%3, topic=%4")
            .arg(msgIdStr).arg(QString("%1").arg(quint16(msgId), 4, 16, QChar('0')).toUpper()).arg(actionStr).arg(topicStr);
        msgHandlingIni.endGroup();

        MsgHandling msgHandling;
        msgHandling.action  = actionMap.value(actionStr, MsgAction::Drop);
        msgHandling.topic   = topicMap.value(topicStr, CloudConnectFrame::Type::NormalPriority);

        if (actionStr.length() > 0 && !actionMap.contains(actionStr)) {
            qWarning().noquote() << QString("CloudConnect: unknown message action \"%1\" for msgId=0x%2 — defaulting to Drop")
                .arg(actionStr).arg(QString("%1").arg(quint16(msgId), 4, 16, QChar('0').toUpper()));
        }

        if (topicStr.length() > 0 && !topicMap.contains(topicStr)) {
            qWarning().noquote() << QString("CloudConnect: unknown message topic \"%1\" for msgId=0x%2 — defaulting to NormalPriority")
                .arg(topicStr).arg(QString("%1").arg(quint16(msgId), 4, 16, QChar('0').toUpper()));
        }

        _msgHandling.insert(msgId, msgHandling);
        msgCount++;
    }
    qInfo().noquote() << QString("CloudConnect: loaded message handling %1 (%2 entries)").arg(msgHandlingPath).arg(msgCount);
}

/*!
 * \brief   CloudConnectController::onFrameReceive
 * \details Unpacks a CAN frame and feeds it to the dispatcher, which reassembles
 *          multi-frame messages per CAN id.
 * \param   frame - the received CAN frame
 */
void CloudConnectController::onFrameReceive(const QCanBusFrame frame)
{
    _dispatcher.onFrameReceive(Can::CanId(frame.frameId()), frame.payload());
}

/*!
 * \brief   CloudConnectController::onMessageReceive
 * \details Applies the message handling policy from LeahiMsgHandling.ini: drops,
 *          forwards unconditionally, or forwards only on payload change. Uses the
 *          section's topic to set the CloudConnectFrame frame msg_id.
 * \param   msg - the reassembled message
 */
void CloudConnectController::onMessageReceive(const Can::Message &msg)
{
    const auto it = _msgHandling.constFind(msg.msgId);
    if (it == _msgHandling.constEnd()) {
        qInfo().noquote() << QString("CloudConnect: no action defined for %1 (0x%2), dropping")
            .arg(leahi::msgIdString(leahi::MsgId(msg.msgId))).arg(msg.msgId, 4, 16, QChar('0'));
        return;
    }

    if (it->action == MsgAction::Drop) {
        qInfo().noquote() << QString("CloudConnect: dropping message %1 (0x%2)")
            .arg(leahi::msgIdString(leahi::MsgId(msg.msgId))).arg(msg.msgId, 4, 16, QChar('0'));
        return;
    }

    auto &[received, cachedMsg] = _msgCache[msg.msgId];
    if (it->action == MsgAction::SendDelta && received &&
        cachedMsg.data.chopped(1) == msg.data.chopped(1)) {
        qInfo().noquote() << QString("CloudConnect: received message %1 (0x%2) did not changed from previous, dropping")
            .arg(leahi::msgIdString(leahi::MsgId(msg.msgId))).arg(msg.msgId, 4, 16, QChar('0'));
        return;
    }

    const QByteArray payload = leahi::canMessageToProtobufByteArray(
        QDateTime::currentDateTime(),
        QStringLiteral("test_device"),
        msg);
    const quint16 sequence = _txSequence++;
    _agentInterface.send(it->topic, sequence, payload);
    _appServer.send(it->topic, sequence, payload);
    received   = true;
    cachedMsg  = msg;
}

/*!
 * \brief   CloudConnectController::onAgentDisconnect
 * \details Resets the received flag on all cache entries so that send_delta
 *          messages are treated as new on the next connection.
 */
void CloudConnectController::onAgentDisconnect()
{
    for (auto &[received, msg] : _msgCache) {
        received = false;
    }
}