/*

  Copyright © 2018 Hasan Yavuz Özderya

  This file is part of serialplot.

  serialplot 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.

  serialplot 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 serialplot.  If not, see <http://www.gnu.org/licenses/>.

*/

#include <QtDebug>

#include "asciireader.h"

/// If set to this value number of channels is determined from input

#define NUMOFCHANNELS_AUTO   (0)

AsciiReader::AsciiReader(QIODevice* device, QObject* parent) :

    AbstractReader(device, parent)

{

    paused = false;

    _numChannels = _settingsWidget.numOfChannels();

    autoNumOfChannels = (_numChannels == NUMOFCHANNELS_AUTO);

    delimiter = _settingsWidget.delimiter();

    connect(&_settingsWidget, &AsciiReaderSettings::numOfChannelsChanged,

            [this](unsigned value)

            {

                _numChannels = value;

                updateNumChannels(); // TODO: setting numchannels = 0, should remove all buffers

                                     // do we want this?

                autoNumOfChannels = (_numChannels == NUMOFCHANNELS_AUTO);

                if (!autoNumOfChannels)

                {

                    emit numOfChannelsChanged(value);

                }

            });

    connect(&_settingsWidget, &AsciiReaderSettings::delimiterChanged,

            [this](QChar d)

            {

                delimiter = d;

            });

}

QWidget* AsciiReader::settingsWidget()

{

    return &_settingsWidget;

}

unsigned AsciiReader::numChannels() const

{

    // TODO: an alternative is to never set _numChannels to '0'

    // do not allow '0'

    return _numChannels == 0 ? 1 : _numChannels;

}

void AsciiReader::enable(bool enabled)

{

    if (enabled)

    {

        firstReadAfterEnable = true;

        QObject::connect(_device, &QIODevice::readyRead,

                         this, &AsciiReader::onDataReady);

    }

    else

    {

        QObject::disconnect(_device, 0, this, 0);

        disconnectSinks();

    }

}

void AsciiReader::onDataReady()

{

    while(_device->canReadLine())

    {

        QString line = QString(_device->readLine());

        // discard only once when we just started reading

        if (firstReadAfterEnable)

        {

            firstReadAfterEnable = false;

            continue;

        }

        // discard data if paused

        if (paused)

        {

            continue;

        }

        // parse data

        line = line.trimmed();

        // Note: When data coming from pseudo terminal is buffered by

        // system CR is converted to LF for some reason. This causes

        // empty lines in the input when the port is just opened.

        if (line.isEmpty())

        {

            continue;

        }

        const SamplePack* samples = parseLine(line);

        if (samples != nullptr) {

            // update number of channels if in auto mode

            if (autoNumOfChannels ) {

                unsigned nc = samples->numChannels();

                if (nc != _numChannels) {

                    _numChannels = nc;

                    updateNumChannels();

                    // TODO: is `numOfChannelsChanged` signal still used?

                    emit numOfChannelsChanged(nc);

                }

            }

            Q_ASSERT(samples->numChannels() == _numChannels);

            // commit data

            feedOut(*samples);

        }

    }

}

SamplePack* AsciiReader::parseLine(const QString& line) const

{

    auto separatedValues = line.split(delimiter, QString::SkipEmptyParts);

    unsigned numComingChannels = separatedValues.length();

    // check number of channels (skipped if auto num channels is enabled)

    if ((!numComingChannels) || (!autoNumOfChannels && numComingChannels != _numChannels))

    {

        qWarning() << "Line parsing error: invalid number of channels!";

        qWarning() << "Read line: " << line;

        return nullptr;

    }

    // parse data per channel

    auto samples = new SamplePack(1, numComingChannels);

    for (unsigned ci = 0; ci < numComingChannels; ci++)

    {

        bool ok;

        samples->data(ci)[0] = separatedValues[ci].toDouble(&ok);

        if (!ok)

        {

            qWarning() << "Data parsing error for channel: " << ci;

            qWarning() << "Read line: " << line;

            delete samples;

            return nullptr;

        }

    }

    return samples;

}

void AsciiReader::saveSettings(QSettings* settings)

{

    _settingsWidget.saveSettings(settings);

}

void AsciiReader::loadSettings(QSettings* settings)

{

    _settingsWidget.loadSettings(settings);

}