#include <QFileDialog>
#include <QFile>
#include <QSerialPortInfo>
#include "qpsxserial.h"
#include "ui_qpsxserial.h"

QPSXSerial::QPSXSerial(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::QPSXSerial)
{
    ui->setupUi(this);
    lost_packet_timer = new QTimer();

    connect(lost_packet_timer, SIGNAL(timeout()), this, SLOT(onPacketLost()));

    connect(ui->loadFile_Btn, SIGNAL(released()), this, SLOT(onLoadFileBtnReleased()));
    connect(ui->updatePorts_Btn, SIGNAL(released()), this, SLOT(onUpdatePortsBtnReleased()));
    connect(ui->send_Btn, SIGNAL(released()), this, SLOT(onSendBtnReleased()));
    connect(ui->ports_ComboBox, SIGNAL(currentIndexChanged(QString)), this, SLOT(onPortSelectedComboBox(QString)));
    connect(&serial, SIGNAL(bytesWritten(qint64)), this, SLOT(onBytesWritten(qint64)));
    connect(&serial, SIGNAL(readyRead()), this, SLOT(onReadyRead(void)));

    ack = false;
    init_timer = NULL;

    ui->exeProgressBar->setVisible(false);

    ui->send_Btn->setEnabled(false);

    ui->inFileName->setVisible(false);

    write_ready = false;
    exe_sent = false;
}

QPSXSerial::~QPSXSerial()
{
    if(serial.isOpen() == true)
    {
        serial.close();
    }

    delete ui;
}

void QPSXSerial::onLoadFileBtnReleased(void)
{
    selectedFolder = QFileDialog::getExistingDirectory( this,
                                                                "Load folder with PSX data",
                                                                "C:/",
                                                                QFileDialog::ShowDirsOnly   );

    if(selectedFolder.isEmpty() == true)
    {
        return;
    }

    selectedFolder.append("/");

    ui->loadedFile_LineEdit->setText(selectedFolder);

    QFile system_f(selectedFolder + "\\SYSTEM.CNF");

    if(system_f.open(QFile::ReadOnly) == false)
    {
        qDebug() << "Could not open " + selectedFolder + "\\SYSTEM.CNF";
        return;
    }

    QTextStream system_txt(&system_f);

    QString fileSelected;

    do
    {
        if(system_txt.atEnd() == true)
        {
            return;
        }

        QString line = system_txt.readLine();

        QStringList tokens = line.split("=");

        if(tokens.isEmpty() == true)
        {
            continue;
        }

        if(tokens.at(0).contains("BOOT") == false)
        {
            continue;
        }

        fileSelected = tokens.at(1).split("\\").at(1);

        fileSelected.chop(2); // Remove ";1" suffix.
        break;

    }while(1);


    inputExe = selectedFolder + fileSelected;
    qDebug() << "inputExe = " + inputExe;
}

void QPSXSerial::onUpdatePortsBtnReleased(void)
{
    ui->ports_ComboBox->clear();

    foreach(QSerialPortInfo port, QSerialPortInfo::availablePorts())
    {
        ui->ports_ComboBox->addItem(port.portName());
    }
}

void QPSXSerial::onSendBtnReleased(void)
{
    qDebug() << serial.isOpen();

    if(serial.isOpen() == false)
    {
        if(selectedPort.isEmpty() == true)
        {
            qDebug() << "No selected port!";
            return;
        }

        serial.setPortName(selectedPort);
        serial.setBaudRate(QSerialPort::Baud115200);
        serial.setParity(QSerialPort::NoParity);
        serial.setDataBits(QSerialPort::Data8);
        serial.setStopBits(QSerialPort::OneStop);

        if(serial.open(QIODevice::ReadWrite) == false)
        {
            qDebug() << "Could not open port " + selectedPort;
            return;
        }

        qDebug() << "Connected succesfully to " + selectedPort;

        if(init_timer == NULL)
        {
            init_timer = new QTimer();

            init_timer->setSingleShot(true);
            init_timer->setInterval(1000);

            connect(init_timer, SIGNAL(timeout(void)), this, SLOT(connectToPSXTimeout(void)));
        }

        ui->exeProgressBar->setVisible(true);

        ui->exeProgressBar->setMinimum(0);
        ui->exeProgressBar->setMaximum(0);

        ui->inFileName->setText("Waiting for PSX response...");

        ui->inFileName->setVisible(true);

        init_timer->start(1000);

        ui->send_Btn->setText("Disconnect from PSX");
    }
    else
    {
        serial.close();
        ui->send_Btn->setText("Send to PSX!");
        qDebug() << "Disconnected";
        init_timer->stop();
    }
}

void QPSXSerial::connectToPSXTimeout(void)
{
    QByteArray ba;

    if(ack == false)
    {
        ba.append(99);

        serial.write(ba);

        //qDebug() << "Retry...";

        init_timer->start(1000);
    }
}

void QPSXSerial::onPortSelectedComboBox(QString port)
{
    selectedPort = port;
    ui->send_Btn->setEnabled(true);
    qDebug() << "Selected port: " + selectedPort;
}

void QPSXSerial::onBytesWritten(qint64)
{
    //qDebug() << "Bytes written: " + QString::number(bytes_written);

    /*byte_sent_received = false;

    while(byte_sent_received == false)
    {
        QApplication::processEvents();
    }*/

    write_ready = true;
}

void QPSXSerial::onReadyRead(void)
{
    static bool first_entered = false;
    QByteArray data = serial.readAll();
    static QTime time = QTime::currentTime();

    //qDebug() << QString("Received ") + QString::number(data.count()) + QString(" bytes.");
    //qDebug() << QString("Took ") + QString::number(time.msecsTo(QTime::currentTime()));

    if(exe_sent == true)
    {
        //qDebug() << data;

        QByteArray header = data.left(5);

        if(header == "cdrom")
        {
            qDebug() << "INPUT FRAME: " + data;
            QString filePath = QString(data);

            filePath.remove("cdrom:\\");

            qDebug() << "selectedFolder = " + selectedFolder;

            filePath.prepend(selectedFolder);

            filePath.replace("\\", "/");

            filePath.chop(2); // Remove ending ";1"

            qDebug() << "filePath = " + filePath;

            QFile f(filePath);

            if(f.open(QFile::ReadOnly) == false)
            {
                qDebug() << "Error while reading input file!";
                return;
            }

            QByteArray file_data = f.readAll();
            quint32 sz = file_data.count();

            sendDataSize(sz);

            while(ack == false)
            {
                QApplication::processEvents();
            }

            qDebug() << "sendData for file...";

            sendData(file_data, filePath);
        }
        else
        {
            if(data.count() == 1)
            {
                if(data.at(0) == 'b')
                {
                    ack = true;
                }
            }
            else
            {
                qDebug() << data;
            }
        }
    }

    if(data.isEmpty() == false)
    {
        quint8 data_byte = (quint8)data.at(0);

        if(data_byte == 'b')
        {
            //qDebug() << "Received ACK";
            // Received handshaking byte. Start transmission!

            ack = true;

            init_timer->stop();

            if(first_entered == false)
            {
                first_entered = true;

                if(sendExe() == false)
                {
                    qDebug() << "An error happened when sending EXE file!";
                }

                exe_sent = true;
            }
        }
    }

    time = QTime::currentTime();
}

bool QPSXSerial::sendExe(void)
{
    QFile f(inputExe);

    if(f.open(QFile::ReadOnly) == false)
    {
        qDebug() << "Could not open input EXE file!";
        return false;
    }

    f.seek(0);

    ack = false;

    QByteArray data = f.read(2048 /* PSX-EXE header */);
    qDebug () << "Sending PSX-EXE header...";

    for(int i = 0; i < 32; i++)
    {
        QByteArray send;
        write_ready = false;

        send.append(data[i]);

        serial.write(send);

        while(write_ready == false)
        {
            QApplication::processEvents();
        }
    }

    while(ack == false)
    {
        QApplication::processEvents();
    }

    qDebug () << "Sending EXE size...";

    qint64 sz = f.size() - 2048;

    sendDataSize((quint32)sz);

    while(ack == false)
    {
        QApplication::processEvents();
    }

    // Send file size without header

    qDebug() << "Dump EXE data...";

    f.seek(2048);

    data = f.readAll();

    qDebug() << data.count();

    sendData(data, inputExe);

    f.close();

    return true;
}

void QPSXSerial::sendDataSize(quint32 size)
{
    QByteArray ar;

    for(unsigned int i = 0; i < sizeof(quint32); i++)
    {
        char send = (char)( size >> (i << 3) );

        QByteArray send_arr;

        send_arr.append(send);

        ar.append(send);

        serial.write(send_arr);

        while(write_ready == false)
        {
            QApplication::processEvents();
        }
    }

    for(unsigned int i = 0; i < sizeof(quint32); i++)
    {
        qDebug() << "0x" + QString::number(ar.at(i), 16);
    }

    ack = false;
}

void QPSXSerial::onPacketLost(void)
{
    qDebug() << "Entering onPacketLost...";

    if(ack == false)
    {

        serial.write(last_packet_sent);
        lost_packet_timer->start(100);
    }
}

void QPSXSerial::sendData(QByteArray data, QString fileName)
{
    ui->exeProgressBar->setVisible(true);
    ui->exeProgressBar->setRange(0, data.count());
    ui->inFileName->setText(fileName);
    ui->inFileName->setVisible(true);

    lost_packet_timer->setInterval(100);
    lost_packet_timer->setSingleShot(true);

    for(int i = 0; i < data.count(); i+= 8)
    {
        QByteArray send;
        ack = false;

        send.append(data.mid(i, 8));

        //qDebug() << "Sent packet";

        serial.write(send);

        last_packet_sent = send;

        lost_packet_timer->start(100);

        while(ack == false)
        {
            QApplication::processEvents();
        }

        ui->exeProgressBar->setValue(i);
    }

    lost_packet_timer->stop();

    ui->exeProgressBar->setValue(data.count());
    ui->inFileName->setText("Transfer complete!");

    ack = false;
}