/*!
 *
 * Copyright (c) 2020-2024 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    MessageDispatcher.cpp
 * \author  (last)      Behrouz NematiPour
 * \date    (last)      31-Jul-2024
 * \author  (original)  Behrouz NematiPour
 * \date    (original)  26-Aug-2020
 *
 */
#include "MessageDispatcher.h"

// Qt
#include <QThread>
#include <QApplication>

// Project
#include "FrameInterface.h"
#include "MessageAcknowModel.h"

//#define DEBUG_ACKBACK_HD_TO_UI
//#define DEBUG_OUT_OF_SYNC

using namespace Can;

/*!
 * \brief MessageDispatcher::MessageDispatcher
 * \details Constructor
 * \param   parent - QObject parent owner object.
 *          Qt handles the children destruction by their parent objects life-cycle.
 */
MessageDispatcher::MessageDispatcher(QObject *parent) : QObject(parent) { }

/*!
 * \brief Message Handler initializer
 */
bool MessageDispatcher::init()
{
    if ( _init ) return false;
    _init = true;

    // runs in the thread
    initConnections();

    //LOG_DEBUG(tr("%1 Initialized").arg(metaObject()->className())); // TODO is this needed?

    return true;
}

/*!
 * \brief   MessageDispatcher::init
 * \details Initialized the Class by calling the init() method first
 *          And initializes the thread vThread by calling initThread
 *          on success init().
 * \param   vThread - the thread
 * \return  returns the return value of the init() method
 */
bool MessageDispatcher::init(QThread &vThread)
{
    if ( ! init() ) return false;
    initThread(vThread);
    return true;
}

/*!
 * \brief   MessageDispatcher::quit
 * \details quits the class
 *          Calls quitThread
 */
void MessageDispatcher::quit()
{
    // disabled coco begin validated: Application termination is not correctly done in coco!!!
    // it has been tested and works perfectly fine in normal run.
    quitThread(); // validated
}
// disabled coco end

/*!
 * \brief Message Handler connections definition
 * \details Initializes the required signal/slot connection between this class and other objects
 *          to be able to communicate.
 */
void MessageDispatcher::initConnections()
{
    // From HD
    connect(&_FrameInterface       , SIGNAL(didFrameReceive  (Can_Id          , const QByteArray   &)),
            this                   ,   SLOT( onFrameReceive  (Can_Id          , const QByteArray   &)));

    // From Message Acknow Model timer timeout.
    connect(&_MessageAcknowModel   , SIGNAL(didFramesTransmit(Can_Id, Sequence, const FrameList    &)),
            this                   ,   SLOT( onFramesTransmit(Can_Id, Sequence, const FrameList    &)));

    connect(&_MessageAcknowModel   , SIGNAL(didFailedTransmit(        Sequence                      )),
            this                   ,   SLOT( onFailedTransmit(        Sequence                      )));
}

/*!
 * \brief   ApplicationController::initThread
 * \details Moves this object into the thread vThread.
 *          And checks that this method is called from main thread.
 *          Also connects quitThread to application aboutToQuit.
 * \param   vThread - the thread
 */
void MessageDispatcher::initThread(QThread &vThread)
{
    // runs in main thread
    Q_ASSERT_X(QThread::currentThread() == qApp->thread() , __func__, "The Class initialization must be done in Main Thread" );
    _thread = &vThread;
    _thread->setObjectName(QString("%1_Thread").arg(metaObject()->className()));
    connect(qApp, SIGNAL(aboutToQuit()), this, SLOT(quit()));
    _thread->start();
    moveToThread(_thread);
}

/*!
 * \brief   MessageDispatcher::quitThread
 * \details Moves this object to main thread to be handled by QApplication
 *          And to be destroyed there.
 */
void MessageDispatcher::quitThread()
{
    // disabled coco begin validated: Application termination is not correctly done in coco!!!
    // it has been tested and works perfectly fine in normal run.

    if ( ! _thread ) return;

    // runs in thread
    moveToThread(qApp->thread()); // validated
}
// disabled coco end

/*!
 * \brief   MessageDispatcher::onFrameReceive
 * \details Upon message has been received over CANBus this slot will be called
 *          by FrameInterface::didFrameReceive signal to process the frame
 *          Upon completion of collected all the required frames
 *          on successful interpretation of the message, emits didActionReceived signal.
 *          The message will be removed from list of the channel vCan_Id messages.
 * \param   vCan_Id   - CANBus channel of the frame
 * \param   vPayload  - Payload of the frame
 */
void MessageDispatcher::onFrameReceive(Can_Id vCan_Id, const QByteArray &vPayload)
{
    // Append a message to the list
    // disabled coco begin validated: if empty (first condition) is true, it must never check for the complete (second condition)
    // because if the list is empty there is no last() item
    if (_messageList[vCan_Id].isEmpty() || _messageList[vCan_Id].last().isComplete()) {
        // disabled coco end
        _messageList[vCan_Id].append(Message());
    }

    // build the message and check.
    if (! buildMessage(vCan_Id, vPayload)) {
        return;
    }
    Message mMessage = _messageList[vCan_Id].last();

    // TODO : must be moved to a MessageModel class
    if (mMessage.isComplete()) {
        rxCount();
        qDebug() << " On dispatch";
        #ifdef DEBUG_OUT_OF_SYNC
            if (_rxSequence != mMessage.sequence) {
                qDebug() << tr("Out of Sync : %1 , %2").arg(_rxSequence).arg(mMessage.sequence);
            }
        #endif
        interpretMessage(mMessage);
    }
}

/*!
 * \brief   MessageDispatcher::onFramesTransmit
 * \details this slots calls the framesTransmit to emit the didFrameTransmit signal
 *          to queue the frame(s) to be sent
 * \param   vSequence  - sequence of the message which is going to be resent. (not used)
 * \param   vFrameList - frame(s) to be sent
 */
void MessageDispatcher::onFramesTransmit(Can_Id vCan_Id, Sequence vSequence, const FrameList &vFrameList)
{
    Q_UNUSED(vSequence)
    framesTransmit(vCan_Id, vFrameList);
}

/*!
 * \brief MessageDispatcher::onFailedTransmit
 * \details the slot which will be called on transmit failed on MessageAcknowModel
 * \param vSequence
 */
void MessageDispatcher::onFailedTransmit(Sequence vSequence)
{
    // disabled coco begin validated: Is a placeholder and has not been implemented yet
    emit didFailedTransmit(vSequence);
}
// disabled coco end

/*!
 * \brief   MessageDispatcher::onActionTransmit
 * \details This slot will be called by ApplicationController::didActionTransmit
 *          upon UI message transmit request and calls MessageDispatcher::actionTransmit method.
 * \param   vActionId - The ActionID of the message
 * \param   vData     - The data of the Message
 */
void MessageDispatcher::onActionTransmit(const QVariantList &vData)
{
    actionTransmit(vData);
}

/*!
 * \brief   MessageDispatcher::onSettingsDone
 * \details The slot to handle didSettingsDone signal of the ApplicationController
 */
void MessageDispatcher::onSettingsDone()
{
    _interpreter.updateUnhandledMessages();
}

// ----------------------------------------------------------------------------------------------------

// ----------------------------------------------------------------------------------------------------

/*!
 * \brief   MessageDispatcher::actionTransmit
 * \details This method is called by slot MessageDispatcher::onActionTransmit
 *          which emits didFrameTransmit on successful interpretation of the requested message
 *          and successfully creating of frame(s).
 * \param   vActionId - The ActionID of the message
 * \param   vData     - The data of the Message
 */
void MessageDispatcher::actionTransmit(const QVariantList &vData, Sequence vSequence, Can_Id vCanId)
{
    txCount();
    if (vSequence == 0) { // initialize
        // it's obvious that this assignment does not effect outside of the function.
        // but is make it easier to just assume the correct value has been passed
        // and still using the same variable (function parameter) as a local variable.
        vSequence = _txSequence;
    }

    QByteArray mData;
    Can_Id canid = vCanId;
    if (! _interpreter.interpretMessage(vData, mData, canid)) {
        //LOG_DEBUG(QString("Incorrect Message, cannot be interpreted, %1").arg(Format::toHexString(vActionId))); // TODO : LogInfo Improvement // TODO is this needed?
        return;
    }

    // TODO : Create a buildFrames method
    FrameList frameList;
    Sequence mSequence = vSequence;
    bool mNeedsAcknow = needsAcknow(canid);
    if (mNeedsAcknow) {
        mSequence = -mSequence;
        if ( ! gDisableAcknowLog ) {
            //LOG_APPED_UI(tr("Ack Req, Sq:%1, ID:%2").arg(mSequence).arg(Format::toHexString(vActionId))); // TODO is this needed?
        }
#ifdef DEBUG_ACKBACK_HD_TO_UI
                qDebug() << tr(" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ UI AckReq : %1 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ").arg(mSequence);
#endif
    }

    // disabled coco begin validated: Has been tested manually but in this function this cannot be false because the message interpreter is doing the same  validation.
    // still checking here in case the logic has changed therefore buildFrame should still validate the message for developer safety.
    if ( ! _builder.buildFrames(mData, frameList, mSequence) ) {
        //LOG_DEBUG(QString("Incorrect Message cannot be built"));  // TODO : LogInfo Improvement // TODO is this needed?
        return;
    }
    // disabled coco end
    if (mNeedsAcknow) {
        // NOTE : here vSequence should be used which is not negative
        // because when we get the Acknow it is not the negative
        // since it does not need Re-Acknow
        // and this is the sequence number which will be used
        // to remove the message from the Acknow list.
        emit didAcknowTransmit(canid, vSequence, frameList);
    }
    framesTransmit(canid, frameList);
}

/*!
 * \brief   MessageDispatcher::framesTransmit
 * \details iterates through all the frames and emits to send the frames
 * \param vCan_Id    - The channel to send the frames to
 * \param vFrameList - List of the frames to be sent
 */
void MessageDispatcher::framesTransmit(Can_Id vCan_Id, const FrameList &vFrameList)
{
    for (const auto &frame : vFrameList) {
        emit didFrameTransmit(vCan_Id, frame);
    }
}

/*!
 * \brief   MessageDispatcher::buildMessage
 * \details Calls the messageBuilder buildMessage method.
 * \param   vCan_Id  - CANBus channel of the frame
 * \param   vPayload - Payload of the frame
 * \return  false on error
 */
bool MessageDispatcher::buildMessage(Can_Id vCan_Id, const QByteArray &vPayload)
{
    if (vPayload.length() < eLenCanFrame) {
        // Each frame has to have exactly 8 (eLenCanFrame) bytes of data and unused bytes should be passed as 00.
        //LOG_DEBUG(QString("Incorrect frame length. Exp:%1,got:%2").arg(eLenCanFrame).arg(vPayload.length()));
        return false;
    }
    if (! _builder.buildMessage(vPayload, _messageList[vCan_Id].last(), vCan_Id)) {
        _messageList[vCan_Id].removeLast();
        return false;
    }
    return true;
}

/*!
 * \brief   MessageDispatcher::checkAcknowReceived
 * \details check if the message was an acknowledge.
 * \param   vMessage - The received message
 * \param   vSrcText - The source entity identifier text
 * \return  true if the message is Acknow
 */
bool MessageDispatcher::checkAcknowReceived(const Message &vMessage, const QString &vSrcText)
{
    Q_UNUSED(vSrcText);
    Sequence      mSequence = vMessage.sequence;
    bool ok = false;
    if ( false ) {
        ok = true;
        if ( ! gDisableAcknowLog ) {
            //LOG_APPED(tr("    ,%1,Ack Bak, Sq:%2").arg(vSrcText).arg(mSequence));
        }
        #ifdef DEBUG_ACKBACK_HD_TO_UI
            qDebug() << tr(" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HD AckBak : %1 %2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ ").arg(mSequence).arg(vMessage.actionId);
        #endif
        emit didAcknowReceive(mSequence);
    }
    return ok;
}

/*!
 * \brief   MessageDispatcher::checkAcknowTransmit
 * \details Sends the Ack message.
 * \param   vMessage - the received message which to check if it may need Ack.
 * \param   vSrcText - the source of the message which needs Ack.
 * \return  returns true if the message needs an Ack (Negative Sequence)
 */
bool MessageDispatcher::checkAcknowTransmit(const Message &vMessage, const QString &vSrcText)
{
    Q_UNUSED(vSrcText);
    bool ok = false;
    Sequence      mSequence = vMessage.sequence;

    // UI shall acknowledge the messages is intended for UI.
    if ( ! needsAcknow(vMessage.can_id)) return ok; // false

    if (mSequence < 0) {
        ok = true;
        if ( ! gDisableAcknowLog ) {
            //LOG_APPED(tr("    ,%1,Ack Req, Sq:%2, ID:%3").arg(vSrcText).arg(mSequence).arg(Format::toHexString(mActionId)));
        }
        #ifdef DEBUG_ACKBACK_HD_TO_UI
            qDebug() << tr(" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ HD AckReq : %1 %2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ ").arg(mSequence).arg(vMessage.actionId);
        #endif
        // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ UI AckBak is immediately handled at the same place.
        QString dstText;
        Can_Id dstID = MessageInterpreter::identifyDestination(vMessage.can_id, &dstText);
        Q_UNUSED(dstID);
        //actionTransmit(GuiActionType::ID_Acknow, {}, -mSequence, dstID); // TODO is this needed?
        if ( ! gDisableAcknowLog ) {
            //LOG_APPED_UI(tr("Ack Bak, Sq:%1, Dst:%2").arg(-mSequence).arg(dstText));
        }
        #ifdef DEBUG_ACKBACK_HD_TO_UI
            qDebug() << tr(" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ UI AckBak : %1 %2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ ").arg(-mSequence).arg(vMessage.actionId);
        #endif
    }
    return ok;
}

/*!
 * \brief   MessageDispatcher::interpretMessage
 * \details Calls the MessageInterpreter interpretMessage method
 *          Regarding the Message Id and the sequence emit different signals
 *          to handle the normal or acknowledge messages.
 * \param   vMessage - The Message
 * \return  false on error
 */
bool MessageDispatcher::interpretMessage(const Message &vMessage)
{
    bool ok = false;
    QVariantList  mData;
    QString srcText;
    MessageInterpreter::identifySource(vMessage.can_id, &srcText);
    if ( ! checkAcknowReceived(vMessage, srcText) ) {   // check if the message was an acknowledge.
        checkAcknowTransmit(vMessage, srcText);         // then  if needs acknow send it immediately.
    }

    // disabled coco begin validated: Has been validated manually. If MessageInterpreter::interpretMessage fails, this also returns false
    if ( _interpreter.interpretMessage( vMessage, mData ) ) {
        ok = true;
        emit didActionReceive(mData);
    }
    // disabled coco end

    _messageList[vMessage.can_id].removeLast();
    return ok;
}

/*!
 * \brief   MessageDispatcher::rxCount
 * \details count received messages up the size of the Sequence type size
 * \return  message count
 */
Sequence MessageDispatcher::rxCount()
{
    // disabled coco begin validated: has been manually validated since it requires so many received messages to reset the seq
    if ( _rxSequence < SEQUENCE_MAX ) {
        ++_rxSequence;
    } else {
        _rxSequence = 1;
    }
    return _rxSequence;
}
// disabled coco end

/*!
 * \brief   MessageDispatcher::txCount
 * \details count transmitted messages up the size of the Sequence type size
 * \return  message count
 */
Sequence MessageDispatcher::txCount()
{
    // disabled coco begin validated: has been manually validated since it requires so many received messages to reset the seq
    if ( _txSequence < SEQUENCE_MAX ) {
        ++_txSequence;
    } else {
        _txSequence = 1;
    }
    return _txSequence;
}
// disabled coco end


/*!
 * \brief   MessageDispatcher::needsAcknow
 * \details List of the CAN channels which need Acknow
 * \param   vCan_Id   - The message CANBus id
 * \return  true if needs an Acknow
 */
bool MessageDispatcher::needsAcknow(Can_Id vCan_Id)
{
    bool ok = true;
    switch(vCan_Id) { // list if the channels UI shall not Ack
    case eChlid_HD_DG   : // 0x008, ///< HD => DG
    case eChlid_DG_HD   : // 0x010, ///< DG => HD
    case eDialin_HD     : // 0x400, ///< dialin => HD
    case eHD_Dialin     : // 0x401, ///< HD => dialin
    case eDialin_DG     : // 0x402, ///< dialin => DG
    case eDG_Dialin     : // 0x403, ///< DG => dialin
        ok = false;                                     break;

    default:                                            break;
    }

    return ok;
}