///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2020 Jon Beniston, M7RCE                                        //
// Copyright (C) 2020 Edouard Griffiths, F4EXB                                   //
//                                                                               //
// 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 as 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 V3 for more details.                               //
//                                                                               //
// You should have received a copy of the GNU General Public License             //
// along with this program. If not, see <http://www.gnu.org/licenses/>.          //
///////////////////////////////////////////////////////////////////////////////////

#include <algorithm>
#include <cmath>

#include <QDebug>
#include <QTcpServer>
#include <QTcpSocket>
#include <QEventLoop>
#include <QTimer>
#include <QSerialPort>
#include <QRegularExpression>

#include "gs232controller.h"
#include "gs232controllerworker.h"
#include "gs232controllerreport.h"

MESSAGE_CLASS_DEFINITION(GS232ControllerWorker::MsgConfigureGS232ControllerWorker, Message)
MESSAGE_CLASS_DEFINITION(GS232ControllerReport::MsgReportAzAl, Message)

GS232ControllerWorker::GS232ControllerWorker() :
    m_msgQueueToFeature(nullptr),
    m_msgQueueToGUI(nullptr),
    m_running(false),
    m_mutex(QMutex::Recursive),
    m_lastAzimuth(-1.0f),
    m_lastElevation(-1.0f),
    m_spidSetOutstanding(false),
    m_spidSetSent(false),
    m_spidStatusSent(false)
{
    connect(&m_pollTimer, SIGNAL(timeout()), this, SLOT(update()));
    m_pollTimer.start(1000);
}

GS232ControllerWorker::~GS232ControllerWorker()
{
    m_inputMessageQueue.clear();
}

void GS232ControllerWorker::reset()
{
    QMutexLocker mutexLocker(&m_mutex);
    m_inputMessageQueue.clear();
    m_lastAzimuth = -1.0f;
    m_lastElevation = -1.0f;
    m_spidSetOutstanding = false;
    m_spidSetSent = false;
    m_spidStatusSent = false;
}

bool GS232ControllerWorker::startWork()
{
    QMutexLocker mutexLocker(&m_mutex);
    connect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
    connect(&m_serialPort, &QSerialPort::readyRead, this, &GS232ControllerWorker::readSerialData);
    if (!m_settings.m_serialPort.isEmpty()) {
        openSerialPort(m_settings);
    }
    m_running = true;
    return m_running;
}

void GS232ControllerWorker::stopWork()
{
    QMutexLocker mutexLocker(&m_mutex);
    // Close serial port as USB/controller activity can create RFI
    if (m_serialPort.isOpen())
        m_serialPort.close();
    disconnect(&m_inputMessageQueue, SIGNAL(messageEnqueued()), this, SLOT(handleInputMessages()));
    disconnect(&m_serialPort, &QSerialPort::readyRead, this, &GS232ControllerWorker::readSerialData);
    m_running = false;
}

void GS232ControllerWorker::handleInputMessages()
{
    Message* message;

    while ((message = m_inputMessageQueue.pop()) != nullptr)
    {
        if (handleMessage(*message)) {
            delete message;
        }
    }
}

bool GS232ControllerWorker::handleMessage(const Message& cmd)
{
    if (MsgConfigureGS232ControllerWorker::match(cmd))
    {
        QMutexLocker mutexLocker(&m_mutex);
        MsgConfigureGS232ControllerWorker& cfg = (MsgConfigureGS232ControllerWorker&) cmd;

        applySettings(cfg.getSettings(), cfg.getForce());
        return true;
    }
    else
    {
        return false;
    }
}

void GS232ControllerWorker::applySettings(const GS232ControllerSettings& settings, bool force)
{
    qDebug() << "GS232ControllerWorker::applySettings:"
            << " m_azimuth: " << settings.m_azimuth
            << " m_elevation: " << settings.m_elevation
            << " m_azimuthOffset: " << settings.m_azimuthOffset
            << " m_elevationOffset: " << settings.m_elevationOffset
            << " m_azimuthMin: " << settings.m_azimuthMin
            << " m_azimuthMax: " << settings.m_azimuthMax
            << " m_elevationMin: " << settings.m_elevationMin
            << " m_elevationMax: " << settings.m_elevationMax
            << " m_tolerance: " << settings.m_tolerance
            << " m_protocol: " << settings.m_protocol
            << " m_serialPort: " << settings.m_serialPort
            << " m_baudRate: " << settings.m_baudRate
            << " force: " << force;

    if ((settings.m_serialPort != m_settings.m_serialPort) || force)
    {
        openSerialPort(settings);
    }
    else if ((settings.m_baudRate != m_settings.m_baudRate) || force)
    {
        m_serialPort.setBaudRate(settings.m_baudRate);
    }

    // Apply offset then clamp

    float azimuth = settings.m_azimuth;
    azimuth += settings.m_azimuthOffset;
    azimuth = std::max(azimuth, (float)settings.m_azimuthMin);
    azimuth = std::min(azimuth, (float)settings.m_azimuthMax);

    float elevation = settings.m_elevation;
    elevation += settings.m_elevationOffset;
    elevation = std::max(elevation, (float)settings.m_elevationMin);
    elevation = std::min(elevation, (float)settings.m_elevationMax);

    // Don't set if within tolerance of last setting
    float azDiff = std::abs(azimuth - m_lastAzimuth);
    float elDiff = std::abs(elevation - m_lastElevation);

    if (((elDiff > settings.m_tolerance) || (m_lastElevation == -1) || force) && (settings.m_elevationMax != 0))
    {
        setAzimuthElevation(azimuth, elevation);
    }
    else if ((azDiff > settings.m_tolerance) || (m_lastAzimuth == -1) || force)
    {
        setAzimuth(azimuth);
    }

    m_settings = settings;
}

void GS232ControllerWorker::openSerialPort(const GS232ControllerSettings& settings)
{
    if (m_serialPort.isOpen()) {
        m_serialPort.close();
    }
    m_serialPort.setPortName(settings.m_serialPort);
    m_serialPort.setBaudRate(settings.m_baudRate);
    if (!m_serialPort.open(QIODevice::ReadWrite))
    {
        qCritical() << "GS232ControllerWorker::openSerialPort: Failed to open serial port " << settings.m_serialPort << ". Error: " << m_serialPort.error();
        if (m_msgQueueToFeature) {
            m_msgQueueToFeature->push(GS232Controller::MsgReportWorker::create(QString("Failed to open serial port %1: %2").arg(settings.m_serialPort).arg(m_serialPort.error())));
        }
    }
    m_lastAzimuth = -1;
    m_lastElevation = -1;
}

void GS232ControllerWorker::setAzimuth(float azimuth)
{
    if (m_settings.m_protocol == GS232ControllerSettings::GS232)
    {
        QString cmd = QString("M%1\r\n").arg((int)std::round(azimuth), 3, 10, QLatin1Char('0'));
        QByteArray data = cmd.toLatin1();
        m_serialPort.write(data);
    }
    else
    {
        setAzimuthElevation(azimuth, m_lastElevation);
    }
    m_lastAzimuth = azimuth;
}

void GS232ControllerWorker::setAzimuthElevation(float azimuth, float elevation)
{
    if (m_settings.m_protocol == GS232ControllerSettings::GS232)
    {
        QString cmd = QString("W%1 %2\r\n").arg((int)std::round(azimuth), 3, 10, QLatin1Char('0')).arg((int)std::round(elevation), 3, 10, QLatin1Char('0'));
        QByteArray data = cmd.toLatin1();
        m_serialPort.write(data);
    }
    else
    {
        qDebug() << "GS232ControllerWorker::setAzimuthElevation " << " AZ " << azimuth << " EL " << elevation;

        if (!m_spidSetSent && !m_spidStatusSent)
        {
            QByteArray cmd(13, (char)0);

            cmd[0] = 0x57;  // Start
            int h = std::round((azimuth + 360.0f) * 2.0f);
            cmd[1] = 0x30 | (h / 1000);
            cmd[2] = 0x30 | ((h % 1000) / 100);
            cmd[3] = 0x30 | ((h % 100) / 10);
            cmd[4] = 0x30 | (h % 10);
            cmd[5] = 2; // 2 degree per impulse
            int v = std::round((elevation + 360.0f) * 2.0f);
            cmd[6] = 0x30 | (v / 1000);
            cmd[7] = 0x30 | ((v % 1000) / 100);
            cmd[8] = 0x30 | ((v % 100) / 10);
            cmd[9] = 0x30 | (v % 10);
            cmd[10] = 2; // 2 degree per impulse
            cmd[11] = 0x2f; // Set cmd
            cmd[12] = 0x20;  // End

            m_serialPort.write(cmd);

            m_spidSetSent = true;
        }
        else
        {
            qDebug() << "GS232ControllerWorker::setAzimuthElevation: Not sent, waiting for status reply";
            m_spidSetOutstanding = true;
        }
    }
    m_lastAzimuth = azimuth;
    m_lastElevation = elevation;
}

void GS232ControllerWorker::readSerialData()
{
    char buf[1024];
    qint64 len;

    if (m_settings.m_protocol == GS232ControllerSettings::GS232)
    {
        while (m_serialPort.canReadLine())
        {
            len = m_serialPort.readLine(buf, sizeof(buf));
            if (len != -1)
            {
                QString response = QString::fromUtf8(buf, len);
                // MD-02 can return AZ=-00 EL=-00 and other negative angles
                QRegularExpression re("AZ=([-\\d]\\d\\d) *EL=([-\\d]\\d\\d)");
                QRegularExpressionMatch match = re.match(response);
                if (match.hasMatch())
                {
                    QString az = match.captured(1);
                    QString el = match.captured(2);
                    //qDebug() << "GS232ControllerWorker::readSerialData read Az " << az << " El " << el;
                    if (getMessageQueueToGUI()) {
                        getMessageQueueToGUI()->push( GS232ControllerReport::MsgReportAzAl::create(az.toFloat(), el.toFloat()));
                    }
                }
                else if (response == "\r\n")
                {
                    // Ignore
                }
                else
                {
                    qDebug() << "GS232ControllerWorker::readSerialData - unexpected GS-232 response \"" << response << "\"";
                    if (m_msgQueueToFeature) {
                        m_msgQueueToFeature->push(GS232Controller::MsgReportWorker::create(QString("Unexpected GS-232 response: %1").arg(response)));
                    }
                }
            }
        }
    }
    else
    {
        while (m_serialPort.bytesAvailable() >= 12)
        {
            len = m_serialPort.read(buf, 12);
            if ((len == 12) && (buf[0] == 0x57))
            {
                double az;
                double el;
                az = buf[1] * 100.0 + buf[2] * 10.0 + buf[3] + buf[4] / 10.0 - 360.0;
                el = buf[6] * 100.0 + buf[7] * 10.0 + buf[8] + buf[9] / 10.0 - 360.0;
                //qDebug() << "GS232ControllerWorker::readSerialData read Az " << az << " El " << el;
                if (getMessageQueueToGUI()) {
                    getMessageQueueToGUI()->push( GS232ControllerReport::MsgReportAzAl::create(az, el));
                }
                if (m_spidStatusSent && m_spidSetSent) {
                    qDebug() << "GS232ControllerWorker::readSerialData - m_spidStatusSent and m_spidSetSent set simultaneously";
                }
                if (m_spidStatusSent) {
                    m_spidStatusSent = false;
                }
                if (m_spidSetSent) {
                    m_spidSetSent = false;
                }
                if (m_spidSetOutstanding)
                {
                    m_spidSetOutstanding = false;
                    setAzimuthElevation(m_lastAzimuth, m_lastElevation);
                }
            }
            else
            {
                QByteArray bytes(buf, (int)len);
                qDebug() << "GS232ControllerWorker::readSerialData - unexpected SPID rot2prog response \"" << bytes.toHex() << "\"";
                if (m_msgQueueToFeature) {
                    m_msgQueueToFeature->push(GS232Controller::MsgReportWorker::create(QString("Unexpected SPID rot2prog response: %1").arg(bytes.toHex().data())));
                }
            }
        }
    }
}

void GS232ControllerWorker::update()
{
    // Request current Az/El from GS-232 controller
    if (m_serialPort.isOpen())
    {
        if (m_settings.m_protocol == GS232ControllerSettings::GS232)
        {
            QByteArray cmd("C2\r\n");
            m_serialPort.write(cmd);
        }
        else
        {
            // Don't send a new status command, if waiting for a previous reply
            if (!m_spidSetSent && !m_spidStatusSent)
            {
                // Status
                QByteArray cmd;
                cmd.append((char)0x57); // Start
                for (int i = 0; i < 10; i++) {
                    cmd.append((char)0x0);
                }
                cmd.append((char)0x1f); // Status
                cmd.append((char)0x20); // End
                m_serialPort.write(cmd);
                m_spidStatusSent = true;
            }
        }
    }
}