#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QSerialPortInfo>
#include <QtDebug>
#include <qwt_plot.h>
#include <limits.h>
#include "utils.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    // init UI signals
    QObject::connect(ui->pbReloadPorts, &QPushButton::clicked,
                     this, &MainWindow::loadPortList);

    QObject::connect(ui->pbOpenPort, &QPushButton::clicked,
                     this, &MainWindow::togglePort);

    QObject::connect(this, &MainWindow::portToggled,
                     this, &MainWindow::onPortToggled);

    QObject::connect(ui->cbPortList,
                     SELECT<const QString&>::OVERLOAD_OF(&QComboBox::activated),
                     this, &MainWindow::selectPort);

    QObject::connect(ui->cbBaudRate,
                     SELECT<const QString&>::OVERLOAD_OF(&QComboBox::activated),
                     this, &MainWindow::selectBaudRate);

    QObject::connect(ui->spNumOfSamples, SELECT<int>::OVERLOAD_OF(&QSpinBox::valueChanged),
                     this, &MainWindow::onNumOfSamplesChanged);

    QObject::connect(ui->cbAutoScale, &QCheckBox::toggled,
                     this, &MainWindow::onAutoScaleChecked);

    QObject::connect(ui->spYmin, SIGNAL(valueChanged(double)),
                     this, SLOT(onYScaleChanged()));

    QObject::connect(ui->spYmax, SIGNAL(valueChanged(double)),
                     this, SLOT(onYScaleChanged()));

    QObject::connect(ui->actionClear, SIGNAL(triggered(bool)),
                     this, SLOT(clearPlot()));

    // setup number format buttons
    numberFormatButtons.addButton(ui->rbUint8,  NumberFormat_uint8);
    numberFormatButtons.addButton(ui->rbUint16, NumberFormat_uint16);
    numberFormatButtons.addButton(ui->rbUint32, NumberFormat_uint32);
    numberFormatButtons.addButton(ui->rbInt8,   NumberFormat_int8);
    numberFormatButtons.addButton(ui->rbInt16,  NumberFormat_int16);
    numberFormatButtons.addButton(ui->rbInt32,  NumberFormat_int32);

    QObject::connect(&numberFormatButtons, SIGNAL(buttonToggled(int, bool)),
                     this, SLOT(onNumberFormatButtonToggled(int, bool)));

    // init port signals
    QObject::connect(&(this->serialPort), SIGNAL(error(QSerialPort::SerialPortError)),
                     this, SLOT(onPortError(QSerialPort::SerialPortError)));

    QObject::connect(&(this->serialPort), &QSerialPort::readyRead,
                     this, &MainWindow::onDataReady);

    loadPortList();
    loadBaudRateList();
    ui->cbBaudRate->setCurrentIndex(ui->cbBaudRate->findText("9600"));

    // set limits for axis limit boxes
    ui->spYmin->setRange((-1) * std::numeric_limits<double>::max(),
                         std::numeric_limits<double>::max());

    ui->spYmax->setRange((-1) * std::numeric_limits<double>::max(),
                         std::numeric_limits<double>::max());

    // init plot
    numOfSamples = ui->spNumOfSamples->value();
    dataArray.resize(numOfSamples);
    dataX.resize(numOfSamples);
    for (int i = 0; i < dataX.size(); i++)
    {
        dataX[i] = i;
    }
    curve.setSamples(dataX, dataArray);
    curve.attach(ui->plot);

    // init number format
    if (numberFormatButtons.checkedId() >= 0)
    {
        selectNumberFormat((NumberFormat) numberFormatButtons.checkedId());
    }
    else
    {
        selectNumberFormat(NumberFormat_uint8);
    }
}

MainWindow::~MainWindow()
{
    if (serialPort.isOpen())
    {
        serialPort.close();
    }
    delete ui;
}

void MainWindow::loadPortList()
{
    QString currentSelection = ui->cbPortList->currentText();

    ui->cbPortList->clear();

    for (auto port : QSerialPortInfo::availablePorts())
    {
        ui->cbPortList->addItem(port.portName());
    }

    // find current selection in the new list, maybe it doesn't exist anymore?
    int currentSelectionIndex = ui->cbPortList->findText(currentSelection);
    if (currentSelectionIndex >= 0)
    {
        ui->cbPortList->setCurrentIndex(currentSelectionIndex);
    }
    else // our port doesn't exist anymore, close port if it's open
    {
        if (serialPort.isOpen()) togglePort();
    }
}

void MainWindow::loadBaudRateList()
{
    ui->cbBaudRate->clear();

    for (auto baudRate : QSerialPortInfo::standardBaudRates())
    {
        ui->cbBaudRate->addItem(QString::number(baudRate));
    }
}

void MainWindow::togglePort()
{
    if (serialPort.isOpen())
    {
        serialPort.close();
        qDebug() << "Port closed, " << serialPort.portName();
        emit portToggled(false);
    }
    else
    {
        serialPort.setPortName(ui->cbPortList->currentText());

        // open port
        if (serialPort.open(QIODevice::ReadWrite))
        {
            qDebug() << "Port opened, " << serialPort.portName();
            emit portToggled(true);

            // set baud rate
            if (!serialPort.setBaudRate(ui->cbBaudRate->currentText().toInt()))
            {
                qDebug() << "Set baud rate failed during port opening: "
                         << serialPort.error();
            }
        }
        else
        {
            qDebug() << "Port open error: " << serialPort.error();
        }
    }
}

void MainWindow::selectPort(QString portName)
{
    // has selection actually changed
    if (portName != serialPort.portName())
    {
        // if another port is already open, close it by toggling
        if (serialPort.isOpen())
        {
            togglePort();

            // open new selection by toggling
            togglePort();
        }
    }
}

void MainWindow::selectBaudRate(QString baudRate)
{
    if (serialPort.isOpen())
    {
        if (!serialPort.setBaudRate(baudRate.toInt()))
        {
            qDebug() << "Set baud rate failed during select: "
                     << serialPort.error();
        }
        else
        {
            qDebug() << "Baud rate changed: " << serialPort.baudRate();
        }
    }
}

void MainWindow::onPortToggled(bool open)
{
    ui->pbOpenPort->setChecked(open);
}

void MainWindow::onDataReady()
{
    if (!ui->actionPause->isChecked())
    {
        int bytesAvailable = serialPort.bytesAvailable();
        if (bytesAvailable < sampleSize)
        {
            return;
        }
        else
        {
            int numOfSamplesToRead =
                (bytesAvailable - (bytesAvailable % sampleSize)) / sampleSize;
            QVector<double> samples(numOfSamplesToRead);
            int i = 0;
            while(i < numOfSamplesToRead)
            {
                samples.replace(i, (this->*readSample)());
                i++;
            }
            addData(samples);
        }
    }
    else
    {
        serialPort.clear(QSerialPort::Input);
    }
}

void MainWindow::onPortError(QSerialPort::SerialPortError error)
{
    switch(error)
    {
        case QSerialPort::NoError :
            break;
        case QSerialPort::ResourceError :
            qDebug() << "Port error: resource unavaliable; most likely device removed.";
            if (serialPort.isOpen())
            {
                qDebug() << "Closing port on resource error: " << serialPort.portName();
                togglePort();
            }
            loadPortList();
            break;
        default:
            qDebug() << "Unhandled port error: " << error;
            break;
    }

}

void MainWindow::addData(QVector<double> data)
{
    int offset = numOfSamples - data.size();

    if (offset < 0)
    {
        for (int i = 0; i < numOfSamples; i++)
        {
            dataArray[i] = data[i - offset];
        }
    }
    else if (offset == 0)
    {
        dataArray = data;
    }
    else
    {
        // shift old samples
        int shift = data.size();
        for (int i = 0; i < offset; i++)
        {
            dataArray[i] = dataArray[i + shift];
        }
        // place new samples
        for (int i = 0; i < data.size(); i++)
        {
            dataArray[offset + i] = data[i];
        }
    }

    // update plot
    curve.setSamples(dataX, dataArray);
    ui->plot->replot();
}

void MainWindow::clearPlot()
{
    dataArray.fill(0.0);

    // update plot
    curve.setSamples(dataX, dataArray);
    ui->plot->replot();
}

void MainWindow::onNumOfSamplesChanged(int value)
{
    unsigned int oldNum = this->numOfSamples;
    numOfSamples = value;

    // resize data arrays
    if (numOfSamples < oldNum)
    {
        dataX.resize(numOfSamples);
        dataArray.remove(0, oldNum - numOfSamples);
    }
    else if(numOfSamples > oldNum)
    {
        dataX.resize(numOfSamples);
        for (unsigned int i = oldNum; i < numOfSamples; i++)
        {
            dataX[i] = i;
            dataArray.prepend(0);
        }
    }
}

void MainWindow::onAutoScaleChecked(bool checked)
{
    if (checked)
    {
        ui->plot->setAxisAutoScale(QwtPlot::yLeft);
        ui->lYmin->setEnabled(false);
        ui->lYmax->setEnabled(false);
        ui->spYmin->setEnabled(false);
        ui->spYmax->setEnabled(false);
    }
    else
    {
        ui->lYmin->setEnabled(true);
        ui->lYmax->setEnabled(true);
        ui->spYmin->setEnabled(true);
        ui->spYmax->setEnabled(true);

        ui->plot->setAxisScale(QwtPlot::yLeft, ui->spYmin->value(),
                               ui->spYmax->value());
    }
}

void MainWindow::onYScaleChanged()
{
    ui->plot->setAxisScale(QwtPlot::yLeft, ui->spYmin->value(),
                           ui->spYmax->value());
}

void MainWindow::onNumberFormatButtonToggled(int numberFormatId, bool checked)
{
    if (checked) selectNumberFormat((NumberFormat) numberFormatId);
}

void MainWindow::selectNumberFormat(NumberFormat numberFormatId)
{
    numberFormat = numberFormatId;

    switch(numberFormat)
    {
        case NumberFormat_uint8:
            sampleSize = 1;
            readSample = &MainWindow::readSampleAs<quint8>;
            break;
        case NumberFormat_int8:
            sampleSize = 1;
            readSample = &MainWindow::readSampleAs<qint8>;
            break;
        case NumberFormat_uint16:
            sampleSize = 2;
            readSample = &MainWindow::readSampleAs<quint16>;
            break;
        case NumberFormat_int16:
            sampleSize = 2;
            readSample = &MainWindow::readSampleAs<qint16>;
            break;
        case NumberFormat_uint32:
            sampleSize = 4;
            readSample = &MainWindow::readSampleAs<quint32>;
            break;
        case NumberFormat_int32:
            sampleSize = 4;
            readSample = &MainWindow::readSampleAs<qint32>;
            break;
    }
}

template<typename T> double MainWindow::readSampleAs()
{
    T data;
    this->serialPort.read((char*) &data, sizeof(data));
    return double(data);
}