#include "candatagrid.h"
#include "ui_candatagrid.h"

#include <QPainter>
#include <QDebug>
#include <QMouseEvent>
#include <QRandomGenerator>

//The program used to generate new colors every time the grid was displayed but that's ugly
//and disorienting. Instead use this list colors I've picked because they're "bright".
//It may need a bit of reorganizing to keep like colors apart and feel free to add some more
//if you want. The program will wrap around if the number of signals in a single message exceeds
//this amount of colors.
//Colors here were generated with: https://colordesigner.io/random-color-generator set to random
//hue bright colors and 40 total colors. I clicked until I kind of liked it.
QVector<QColor> signalColors =
{
    QColor(101, 104, 159),
    QColor(237, 35, 109),
    QColor(216, 53, 221),
    QColor(37, 252, 220),
    QColor(8, 160, 53),
    QColor(226, 111, 11),
    QColor(216, 59, 2),
    QColor(249, 246, 27),
    QColor(214, 21, 34),
    QColor(178, 219, 74),
    QColor(214, 55, 71),
    QColor(80, 198, 206),
    QColor(83, 214, 201),
    QColor(35, 210, 237),
    QColor(25, 170, 105),
    QColor(110, 221, 55),
    QColor(30, 38, 181),
    QColor(79, 124, 209),
    QColor(7, 91, 175),
    QColor(14, 234, 208),
    QColor(125, 45, 168),
    QColor(176, 211, 80),
    QColor(255, 206, 48),
    QColor(202, 226, 93),
    QColor(201, 99, 232),
    QColor(13, 72, 135),
    QColor(32, 45, 219),
    QColor(197, 26, 216),
    QColor(119, 15, 216),
    QColor(97, 18, 150),
    QColor(242, 16, 242),
    QColor(177, 5, 196),
    QColor(214, 10, 102),
    QColor(9, 50, 155),
    QColor(201, 38, 76),
    QColor(202, 234, 72),
    QColor(59, 191, 57),
    QColor(0, 25, 170),
    QColor(7, 186, 93),
    QColor(29, 211, 147)
};

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

    gridMode = GridMode::CHANGED_BITS;

    memset(data, 0, 64);
    memset(refData, 0, 64);
    memset(usedData, 0, 64);
    for (int j = 0; j < 512; j++) usedSignalName[j] = QString();
    bytesToDraw = 8; //default to the old behavior
    for (int x = 0; x < 8; x++)
        for (int y = 0; y < 64; y++)
        {
            textStates[y][x] = GridTextState::NORMAL;
            heatData[y * 8 + x] = 0;
        }

    blackBrush = QBrush(Qt::black);
    whiteBrush = QBrush(Qt::white);
    redBrush = QBrush(Qt::red);
    greenBrush = QBrush(Qt::green);
    greenHashBrush = QBrush(QColor(0, 0xB6, 0), Qt::BDiagPattern);
    blackHashBrush = QBrush(QColor(0, 0, 0), Qt::FDiagPattern);
    grayBrush = QBrush(QColor(230,230,230));
    xOffset = 0;
    yOffset = 0;

    //generate the palette

    /* //this one looks sort of like a fire. It was my first idea but never really got to where I liked it
    for(int x = 1; x < 256; x++)
    {
        int lum = x * 2;
        if (lum < 40) lum = 40;
        if (lum > 250) lum = 250;
        fire[x] = QColor::fromHsl((int)(x / 3.5), 255 - ((256 - x) / 10), lum);
    }
    */

    for(int x = 1; x < 256; x++)
    {
        int hue = 256 - x;
        fire[x] = QColor::fromHsl(hue, 255, 127);
    }

    //the 0th entry should always be black and really stand out from the rest
    fire[0] = Qt::black;
}

CANDataGrid::~CANDataGrid()
{
    delete ui;
}

GridMode CANDataGrid::getMode()
{
    return gridMode;
}

void CANDataGrid::setMode(GridMode mode)
{
    gridMode = mode;
}

void CANDataGrid::setBytesToDraw(int num)
{
    bytesToDraw = num;
    //this->update();
}

void CANDataGrid::mousePressEvent(QMouseEvent *event)
{
    QPoint clickedPoint = event->pos();
    if (event->button() == Qt::LeftButton)
    {
        //qDebug() << "Mouse Loc " << clickedPoint;
        clickedPoint -= upperLeft;
        if (clickedPoint.x() < 0 || clickedPoint.y() < 0)
        {
            //qDebug() << "Clicked outside the grid";
            return;
        }
        int x = clickedPoint.x() / gridSize.x();
        int y = clickedPoint.y() / gridSize.y();
        qDebug() << "Grid square clicked " << x << " " << y;
        int bitClicked = gridToBitPosition(x, y);
        //this control is the ultimate authority on which bit is at which grid so what we're going to do now
        //is return the actual bit so everyone else doesn't have to try to calculate it. When someone clicks
        //what the parent GUI really cares about is which bit that was.
        emit gridClicked(bitClicked);
    }
    if (event->button() == Qt::MiddleButton) //cycle through the various grid layouts for frame sizes
    {
        //qDebug() << "Middle Button";
        if (bytesToDraw < 9) bytesToDraw = 16;
        else if (bytesToDraw < 31) bytesToDraw = 32;
        else if (bytesToDraw < 63) bytesToDraw = 64;
        else if (bytesToDraw > 32) bytesToDraw = 8;
        this->update();
    }

    //right click is exactly like left click but the emitted signal is different so that
    //external code can differentiate which button was pressed
    if (event->button() == Qt::RightButton)
    {
        clickedPoint -= upperLeft;
        if (clickedPoint.x() < 0 || clickedPoint.y() < 0)
        {
            return;
        }
        int x = clickedPoint.x() / gridSize.x();
        int y = clickedPoint.y() / gridSize.y();
        int bitClicked = gridToBitPosition(x, y);
        emit gridRightClicked(bitClicked);
    }
}

void CANDataGrid::setCellTextState(int bitPos, GridTextState state)
{
    //textStates has two dimensions but they are NOT X and Y and don't necessarily correspond to X and Y in the grid
    int byte = bitPos / 8;
    int bit = bitPos & 7;
    textStates[byte][bit] = state;
    this->update();
}

GridTextState CANDataGrid::getCellTextState(int bitPos)
{
    int byte = bitPos / 8;
    int bit = bitPos & 7;
    return textStates[byte][bit];
}

void CANDataGrid::setUsedSignalName(int bit, QString signal)
{
    if (bit < 0) return;
    if (bit > 511) return;
    usedSignalName[bit] = signal;
}

QString CANDataGrid::getUsedSignalName(int bit)
{
    if (bit < 0) return 0;
    if (bit > 511) return 0;
    return usedSignalName[bit];
}

void CANDataGrid::paintEvent(QPaintEvent *event)
{
    Q_UNUSED(event);

    paintCommonBeginning();
    paintGridCells();
    paintCommonEnding();
}

/*
 * CAN-FD causes the need to support these sizes: 8, 12, 16, 20, 24, 32, 48, 64 bytes.
 * It's probably OK to ignore 12 and just go straight from 8 to 16 where each cell is subdivided in half along the X axis
 * Then 12 is just 16 minus some bits that never can get used. Then jump to 32 drawn cells from there. That would be also
 * subdividing along the Y axis. Obviously, as before, 24 is just 32 but with unusable bits. Lastly, subdivide X yet again
 * so now it's in quarters. This allows for 64 bits (48 is likewise just 64 with unusable bits)
*/
void CANDataGrid::paintCommonBeginning()
{
    int x;

    painter = new QPainter(this);
    viewport = painter->viewport();

    neededXDivisions = 8;
    neededYDivisions = 8;

    int textRestrict = qMax(neededXDivisions, neededYDivisions);

    if (bytesToDraw > 8)
    {
        neededXDivisions = 16;
    }
    if (bytesToDraw > 16)
    {
        neededXDivisions = 16;
        neededYDivisions = 16;
    }
    if (bytesToDraw > 32)
    {
        neededXDivisions = 32;
    }

    if (gridMode != GridMode::SIGNAL_VIEW)
    {
        bigTextSize = qMin(viewport.size().height(), viewport.size().width()) / (textRestrict * 3.25);
        smallTextSize = qMin(viewport.size().height(), viewport.size().width()) / (textRestrict * 4.0);
    }
    else
    {
        bigTextSize = qMin(viewport.size().height(), viewport.size().width()) / (textRestrict * 3.50);
        smallTextSize = qMin(viewport.size().height(), viewport.size().width()) / (textRestrict * 5.5);
    }
    sigNameTextSize = qMin(viewport.size().height(), viewport.size().width()) / (textRestrict * 5.0);

    painter->setPen(QPen(QApplication::palette().color(QPalette::Text)));
    mainFont.setPixelSize(bigTextSize);
    painter->setFont(mainFont);
    smallFont.setPixelSize(smallTextSize);
    boldFont.setPixelSize(bigTextSize);
    boldFont.setBold(true);
    sigNameFont.setPixelSize(sigNameTextSize);

    smallMetric = new QFontMetrics(sigNameFont);
    largeMetric = new QFontMetrics(mainFont);

    xOffset = smallMetric->maxWidth();
    yOffset = smallMetric->height();

    xSpan = viewport.right() - viewport.left() - xOffset;
    ySpan = viewport.bottom() - viewport.top() - yOffset;

    qDebug() << "XSpan" << xSpan << " YSpan " << ySpan;

    xSector = xSpan / neededXDivisions;
    ySector = ySpan / neededYDivisions;

    qDebug() << "XSector " << xSector << " YSector " << ySector;

    nearX = viewport.left() + xOffset;
    nearY = viewport.top() + yOffset;
    farX = nearX + xSector * neededXDivisions;
    farY = nearY + ySector * neededYDivisions;

    //painter->setFont(boldFont);
    painter->setFont(smallFont);

    //draw grid by doing vertical and horizontal lines. This is not needed normally but helps when developing new code. Only uncomment for testing
/*
    for (int y = 0; y <= neededYDivisions; y++)
    {
        painter->drawLine(nearX, nearY + (y * ySector), farX, nearY + (y * ySector) );
    }

    for (int x = 0; x <= neededXDivisions; x++)
    {
        painter->drawLine(nearX + (x * xSector), nearY, nearX + (x * xSector), farY);
    }
*/

    for (x = 0; x < neededXDivisions; x++)
    {
        int num = (neededXDivisions - 1) - x;
        num = num & 7;
        painter->drawText(QRect(nearX + (x * xSector), viewport.top(), xSector, viewport.top() + smallMetric->height()), Qt::AlignCenter, QString::number(num));
    }

    int skip = neededXDivisions / 8;
    for (int y = 0; y < neededYDivisions; y++)
    {
        painter->drawText(QRect(viewport.left() + 2, nearY + (ySector * y), xOffset, ySector), Qt::AlignCenter, QString::number(y * skip));
    }

    painter->setPen(QPen(Qt::black));
    painter->setFont(mainFont);
}

void CANDataGrid::paintGridCells()
{
    int x, y, bit;
    unsigned char prevByte, thisByte;
    bool thisBit, prevBit;
    QString usedSigName;
    QString prevSigName;

    //now, color the bitfield by seeing if a given bit is freshly set/unset in the new data
    //compared to the old. Bits that are not set in either are white, bits set in both are black
    //bits that used to be set but now are unset are red, bits that used to be unset but now are set
    //are green

    for (y = 0; y < neededYDivisions; y++)
    {
        for (x = 0; x < neededXDivisions; x++)
        {
            int byteIdx = (y * (neededXDivisions / 8) + (x / 8));
            thisByte = data[byteIdx];
            prevByte = refData[byteIdx];
            int bitIdx = ((neededXDivisions - 1) - x) & 7;
            bit = (byteIdx * 8) + bitIdx;
            thisBit = false;
            prevBit = false;
            if ((thisByte & (1 << bitIdx)) == (1 << bitIdx)) thisBit = true;
            if ((prevByte & (1 << bitIdx)) == (1 << bitIdx)) prevBit = true;

            if (gridMode == GridMode::HEAT_VIEW)
            {
                painter->setBrush(QBrush(fire[heatData[bit]]));
            }
            else
            {
                if (thisBit)
                {
                    if (prevBit)
                    {
                        if ((signalColors.count() > 0) && (gridMode == GridMode::SIGNAL_VIEW)) painter->setBrush(blackHashBrush);
                        else painter->setBrush(blackBrush);
                    }
                    else
                    {
                        if ((signalColors.count() > 0) && (gridMode == GridMode::SIGNAL_VIEW)) painter->setBrush(greenHashBrush);
                        else painter->setBrush(greenBrush);
                    }
                }
                else
                {
                    if (prevBit)
                    {
                        painter->setBrush(redBrush);
                    }
                    else
                    {
                        usedSigName = QString();
                        if ((usedData[byteIdx] & (1 << bitIdx)) == (1 << bitIdx))
                        {
                            if (gridMode == GridMode::SIGNAL_VIEW) usedSigName = getUsedSignalName(bit);
                            if (usedSigName == QString())
                            {
                                grayBrush = QBrush(QColor(0xB6, 0xB6, 0xB6), Qt::BDiagPattern);
                                painter->setBrush(grayBrush);
                            }
                            else
                            {
                                int idx = 0;
                                foreach (char c, usedSigName.toUtf8())
                                {
                                    idx += c;
                                }
                                idx = idx % signalColors.length(); //can only use as many colors as have been defined
                                painter->setBrush(QBrush(signalColors[idx]));
                            }
                        }
                        else painter->setBrush(whiteBrush);
                    }
                }
            }

            painter->drawRect(nearX + (x * xSector), nearY + (y * ySector), xSector, ySector);
            switch (textStates[byteIdx][bitIdx])
            {
            case GridTextState::NORMAL:
                if (thisBit && prevBit) painter->setPen(QPen(Qt::gray));
                else painter->setPen(QPen(Qt::black));
                painter->setFont(mainFont);
                break;
            case GridTextState::BOLD_BLUE:
                painter->setPen(QPen(Qt::blue));
                painter->setFont(boldFont);
                break;
            case GridTextState::INVERT:
                painter->setFont(mainFont);
                QColor brushColor = painter->brush().color();
                painter->setPen(QColor(255-brushColor.red(), 255-brushColor.green(), 255-brushColor.blue()));
                break;
            }
            //change style of bit number output for current signal
            //if (thisBit) painter->setFont(boldFont);
           // else painter->setFont(mainFont);
            //painter->setFont(smallFont);
            if (gridMode != GridMode::SIGNAL_VIEW)
                painter->drawText(QRect(nearX + (x * xSector), nearY + (y * ySector), xSector, ySector), Qt::AlignCenter, QString::number(bit)); //center center of grid
            else
                painter->drawText(QRect(nearX + (x * xSector), nearY + (y * ySector), xSector, ySector), Qt::AlignLeft, QString::number(bit)); //upper left of grid

            painter->setFont(mainFont);
            painter->setPen(QPen(Qt::black));
        }
    }


    /*
     * now  we'll go through all the bits again and try to label over top of the grid
     * We already have a big bitmap that tells us which signals occupy which bits so every time there is a new
     * signal look ahead to see if there's room in the row to just run the signal name through as long as needed.
    */
    if ( gridMode == GridMode::SIGNAL_VIEW )
    {
        painter->setFont(sigNameFont);

        for (y = 0; y < neededYDivisions; y++)
        {
            for (x = 0; x < neededXDivisions; x++)
            {
                int byteIdx = (y * (neededXDivisions / 8) + (x / 8));
                int bitIdx = ((neededXDivisions - 1) - x) & 7;
                bit = (byteIdx * 8) + bitIdx;
                usedSigName = QString();
                if ((usedData[byteIdx] & (1 << bitIdx)) == (1 << bitIdx))
                {
                    usedSigName = getUsedSignalName(bit);
                    if ((usedSigName.length() > 0) && (prevSigName != usedSigName) )
                    {
                        prevSigName = usedSigName;

                        int textWidth = smallMetric->horizontalAdvance(prevSigName);

                        int usableWidth = getSignalRowRun(usedSigName, bit);
                        qDebug() << "Width this row: " << usableWidth;
                        usableWidth *= xSector;

                        if (textWidth > usableWidth) //signal name is too long for space we've got on this row. Try to wrap it
                        {
                            int numAvgChars = xSector / smallMetric->averageCharWidth();
                            painter->drawText(nearX + x * xSector + 5, nearY + (y * ySector) + smallMetric->height() * 1.6, prevSigName.left(numAvgChars - 1));
                            QString remainder = prevSigName.mid(numAvgChars - 1, -1);
                            textWidth = smallMetric->horizontalAdvance(prevSigName);
                            if (textWidth > xSector)
                            {
                                painter->drawText(nearX + x * xSector + 12, nearY + (y * ySector) + smallMetric->height() * 2.6, remainder.left(numAvgChars - 1));
                            }
                            else painter->drawText(nearX + x * xSector + 12, nearY + (y * ySector) + smallMetric->height() * 2.6, remainder);

                        }
                        else
                        {
                            //first see if we even have enough room to use a bigger font and use that if so. Otherwise stick with the normal font
                            textWidth = largeMetric->horizontalAdvance(prevSigName);
                            if (textWidth < usableWidth)
                            {
                                painter->setFont(mainFont);
                                QSize size = QSize(usableWidth, ySector - smallMetric->height() * 1.0);
                                painter->drawText(QRect(nearX + x * xSector, nearY + (y * ySector) + smallMetric->height() * 1.0, size.width(), size.height()), Qt::AlignCenter, prevSigName);
                                painter->setFont(sigNameFont);
                            }
                            else
                            {
                                QSize size = QSize(usableWidth, ySector - smallMetric->height() * 1.0);
                                painter->drawText(QRect(nearX + x * xSector, nearY + (y * ySector) + smallMetric->height() * 1.0, size.width(), size.height()), Qt::AlignCenter, prevSigName);
                            }
                        }
                    }
                }
            }
        }
    }
}

//starting at the given coords, go right / increment X until either we hit the end of the signal or the end of the row, whichever is first.
//return how many grid cells that was. The part that sucks is that bits aren't really in "bit" order so you can't just increment the bit number
int CANDataGrid::getSignalRowRun(QString sigName, int startBit)
{
    qDebug() << "SigName: " << sigName << " startBit " << startBit;
    int width = 0;
    QPoint gridPt = getGridPointFromBitPosition(startBit);
    int x = gridPt.x();
    int y = gridPt.y();
    for (int xx = x; xx < neededXDivisions; xx++)
    {
        int bit = gridToBitPosition(xx, y);
        if (usedSignalName[bit] == sigName) width++;
        else return width;
    }

    return width;
}

void CANDataGrid::paintCommonEnding()
{
    //these are used to make it easy to figure out which grid has been clicked on during mousedown events
    upperLeft.setX(nearX);
    upperLeft.setY(nearY);
    gridSize.setX(xSector);
    gridSize.setY(ySector);

    //and we don't need these anymore after we're done drawing
    delete painter;
    delete smallMetric;
}

//given a grid cell we return which bit position that is within the CAN frame.
int CANDataGrid::gridToBitPosition(int x, int y)
{
    int byteIdx = (y * (neededXDivisions / 8) + (x / 8));
    int bitIdx = ((neededXDivisions - 1) - x) & 7;
    int bit = (byteIdx * 8) + bitIdx;
    return bit;
}

//inverse of above. Given a bit position we calculate where that would be in our grid
QPoint CANDataGrid::getGridPointFromBitPosition(int bitPos)
{
    int tempBit = bitPos;
    //neededXDivisions tells us how many bits are on a single line.
    //From there we can easily determine which Y row we're in with simple division
    int y = bitPos / neededXDivisions;
    //x is more complicated because the bits go in a sort of stairstep pattern 7654321076543210
    tempBit = (bitPos - (neededXDivisions * y));
    int x = tempBit & 0xF8; //get the byte offset in the line
    x = x + (7- (tempBit & 7)); //reverse the bits in the byte

    return QPoint(x, y);
}

void CANDataGrid::saveImage(QString filename, int width, int height)
{
    Q_UNUSED(width); //currently unused but I want to use them in the future
    Q_UNUSED(height);
    //can't quite do the below commented out stuff
    //it works but doesn't scale the image into that pixmap. Need to
    //figure out how to draw the size of the pixmap
    /*
    QSize pSize;

    if (width == 0) pSize.setWidth(this->size().width());
        else pSize.setWidth(width);

    if (height == 0) pSize.setHeight(this->size().height());
        else pSize.setHeight(height);

    QPixmap pixmap(pSize);
    */
    QPixmap pixmap(this->size());

    this->render(&pixmap);
    pixmap.save(filename); //QT will automatically pick the file format given the extension
}

//these next three functions will copy the needed number of bytes from the passed buffer but you'd better have a large enough buffer or they'll get junk
//this probably won't crash the program but it would yield some really strange output. This is only really an issue for CAN-FD traffic. Make sure you
//have large enough buffers!
void CANDataGrid::setReference(unsigned char *newRef, bool bUpdate = true)
{
    int bytesToTransfer = (bytesToDraw + 7) & 0xF8; //force copying in 8 byte increments
    memcpy(refData, newRef, bytesToTransfer);
    //clear all data past that point just to be sure we don't have garbage left over
    if (bytesToTransfer < 64) memset(refData + bytesToTransfer, 0, 64 - bytesToTransfer);
    if (bUpdate) this->update();
}

void CANDataGrid::updateData(unsigned char *newData, bool bUpdate = true)
{
    int bytesToTransfer = (bytesToDraw + 7) & 0xF8; //force copying in 8 byte increments
    memcpy(data, newData, bytesToTransfer);
    //clear all data past that point just to be sure we don't have garbage left over
    if (bytesToTransfer < 64) memset(refData + bytesToTransfer, 0, 64 - bytesToTransfer);
    if (bUpdate) this->update();
}

void CANDataGrid::setUsed(unsigned char *newData, bool bUpdate = false)
{
    int bytesToTransfer = (bytesToDraw + 7) & 0xF8; //force copying in 8 byte increments
    memcpy(usedData, newData, bytesToTransfer);
    //clear all data past that point just to be sure we don't have garbage left over
    if (bytesToTransfer < 64) memset(refData + bytesToTransfer, 0, 64 - bytesToTransfer);
    if (bUpdate) this->update();
}

void CANDataGrid::setHeat(unsigned char *newData)
{
    memcpy(heatData, newData, 512);
    this->update();
}