#include "graph.h"
#include <QDebug>

PlotTimeGraph::PlotTimeGraph(QCPAxis *keyAxis, QCPAxis *valueAxis) : QCPGraph(keyAxis, valueAxis) { }

void PlotTimeGraph::addColoredSegment(double lowerValue, double upperValue, QPen pen, QBrush brush)
{
    if (qFuzzyCompare(lowerValue, upperValue)) {
        qDebug() << "Invalid segment : identical values";
        return;
    }

    mLowerValues.append(lowerValue);
    mUpperValues.append(upperValue);
    mPens.append(pen);
    mBrushs.append(brush);
}

void PlotTimeGraph::clearColoredSegments()
{
    mLowerValues.clear();
    mUpperValues.clear();
    mPens.clear();
    mBrushs.clear();
}

void PlotTimeGraph::draw(QCPPainter *painter)
{
    if (!mKeyAxis || !mValueAxis) {
        qDebug() << Q_FUNC_INFO << "invalid key or value axis";
        return;
    }
    if (mKeyAxis.data()->range().size() <= 0 || mDataContainer->isEmpty())
        return;
    if (mLineStyle == lsNone && mScatterStyle.isNone())
        return;

    QVector<QPointF> lines, scatters;  // line and (if necessary) scatter pixel coordinates will be stored here while
                                       // iterating over segments

    QCPDataSelection thresholdsSelection;
    QList<GraphColoredSegment> allSegments;

    for (int index = 0; index < mLowerValues.count(); index++) {
        QCPGraphDataContainer::const_iterator begin = mDataContainer->constEnd();
        for (QCPGraphDataContainer::const_iterator it = mDataContainer->constBegin(); it != mDataContainer->constEnd();
             ++it) {
            if (it->value >= mLowerValues.at(index) && it->value < mUpperValues.at(index)) {
                if (begin == mDataContainer->constEnd())
                    begin = it;
            } else {
                if (begin != mDataContainer->constEnd()) {
                    thresholdsSelection.addDataRange(
                            QCPDataRange(begin - mDataContainer->constBegin(), it - mDataContainer->constBegin()));
                    allSegments.append(GraphColoredSegment(
                            QCPDataRange(begin - mDataContainer->constBegin(), it - mDataContainer->constBegin()),
                            mPens.at(index), mBrushs.at(index)));
                    begin = mDataContainer->constEnd();
                }
            }
        }
        if (begin != mDataContainer->constEnd()) {
            thresholdsSelection.addDataRange(QCPDataRange(begin - mDataContainer->constBegin(), dataCount()));
            allSegments.append(GraphColoredSegment(QCPDataRange(begin - mDataContainer->constBegin(), dataCount()),
                                                   mPens.at(index), mBrushs.at(index)));
        }
    }

    auto baseSegments = thresholdsSelection.inverse(QCPDataRange(0, dataCount())).dataRanges();

    for (int k = 0; k < baseSegments.count(); k++) {
        allSegments.append(GraphColoredSegment(baseSegments.at(k).adjusted(-1, 1), mPen, mBrush));
    }

    std::sort(allSegments.begin(), allSegments.end(), lessThanSegment);

    for (int i = 0; i < allSegments.size(); ++i) {
        QCPDataRange lineDataRange = allSegments.at(i).dataRange();
        getLines(&lines, lineDataRange);

        painter->setBrush(allSegments.at(i).brush());
        painter->setPen(Qt::NoPen);
        drawFill(painter, &lines);

        // draw line:
        if (mLineStyle != lsNone) {
            painter->setPen(allSegments.at(i).pen());
            painter->setBrush(Qt::NoBrush);
            if (mLineStyle == lsImpulse)
                drawImpulsePlot(painter, lines);
            else
                drawLinePlot(painter, lines);  // also step plots can be drawn as a line plot
        }

        // draw scatters:
        QCPScatterStyle finalScatterStyle = mScatterStyle;
        if (!finalScatterStyle.isNone()) {
            finalScatterStyle.setPen(allSegments.at(i).pen());
            getScatters(&scatters, allSegments.at(i).dataRange());
            drawScatterPlot(painter, scatters, finalScatterStyle);
        }
    }
}

void PlotTimeGraph::drawFill(QCPPainter *painter, QVector<QPointF> *lines) const
{
    if (mLineStyle == lsImpulse)
        return;  // fill doesn't make sense for impulse plot
    if (painter->brush().style() == Qt::NoBrush || painter->brush().color().alpha() == 0)
        return;

    applyFillAntialiasingHint(painter);
    QVector<QCPDataRange> segments = getNonNanSegments(lines, keyAxis()->orientation());
    if (!mChannelFillGraph) {
        // draw base fill under graph, fill goes all the way to the zero-value-line:
        for (int i = 0; i < segments.size(); ++i)
            painter->drawPolygon(getCustomFillPolygon(lines, segments.at(i)));
    } else {
        // draw fill between this graph and mChannelFillGraph:
        QVector<QPointF> otherLines;
        mChannelFillGraph->getLines(&otherLines, QCPDataRange(0, mChannelFillGraph->dataCount()));
        if (!otherLines.isEmpty()) {
            QVector<QCPDataRange> otherSegments =
                    getNonNanSegments(&otherLines, mChannelFillGraph->keyAxis()->orientation());
            QVector<QPair<QCPDataRange, QCPDataRange>> segmentPairs =
                    getOverlappingSegments(segments, lines, otherSegments, &otherLines);
            for (int i = 0; i < segmentPairs.size(); ++i)
                painter->drawPolygon(
                        getChannelFillPolygon(lines, segmentPairs.at(i).first, &otherLines, segmentPairs.at(i).second));
        }
    }
}

const QPolygonF PlotTimeGraph::getCustomFillPolygon(const QVector<QPointF> *lineData, QCPDataRange segment) const
{
    if (segment.size() < 2)
        return QPolygonF();
    QPolygonF result(segment.size() + 2);

    result[0] = getCustomFillBasePoint(lineData->at(segment.begin()));
    std::copy(lineData->constBegin() + segment.begin(), lineData->constBegin() + segment.end(), result.begin() + 1);
    result[result.size() - 1] = getCustomFillBasePoint(lineData->at(segment.end() - 1));

    return result;
}

QPointF PlotTimeGraph::getCustomFillBasePoint(QPointF matchingDataPoint) const
{
    QCPAxis *keyAxis   = mKeyAxis.data();
    QCPAxis *valueAxis = mValueAxis.data();
    if (!keyAxis || !valueAxis) {
        qDebug() << Q_FUNC_INFO << "invalid key or value axis";
        return QPointF();
    }

    double fillRefValue;
    if (mFillStyle == fsZero)
        fillRefValue = valueAxis->coordToPixel(0);
    else
        fillRefValue = valueAxis->axisRect()->bottom();

    QPointF result;
    if (valueAxis->scaleType() == QCPAxis::stLinear) {
        if (keyAxis->orientation() == Qt::Horizontal) {
            result.setX(matchingDataPoint.x());
            result.setY(fillRefValue);
        } else {  // keyAxis->orientation() == Qt::Vertical
            result.setX(fillRefValue);
            result.setY(matchingDataPoint.y());
        }
    } else {  // valueAxis->mScaleType == QCPAxis::stLogarithmic
        // In logarithmic scaling we can't just draw to value 0 so we just fill all the way
        // to the axis which is in the direction towards 0
        if (keyAxis->orientation() == Qt::Vertical) {
            if ((valueAxis->range().upper < 0 && !valueAxis->rangeReversed())
                || (valueAxis->range().upper > 0
                    && valueAxis->rangeReversed()))  // if range is negative, zero is on opposite side of key axis
                result.setX(keyAxis->axisRect()->right());
            else
                result.setX(keyAxis->axisRect()->left());
            result.setY(matchingDataPoint.y());
        } else if (keyAxis->axisType() == QCPAxis::atTop || keyAxis->axisType() == QCPAxis::atBottom) {
            result.setX(matchingDataPoint.x());
            if ((valueAxis->range().upper < 0 && !valueAxis->rangeReversed())
                || (valueAxis->range().upper > 0
                    && valueAxis->rangeReversed()))  // if range is negative, zero is on opposite side of key axis
                result.setY(keyAxis->axisRect()->top());
            else
                result.setY(keyAxis->axisRect()->bottom());
        }
    }
    return result;
}

PlotTimeGraph::FillStyle PlotTimeGraph::getFillStyle() const
{
    return mFillStyle;
}

void PlotTimeGraph::setFillStyle(const FillStyle &fillStyle)
{
    mFillStyle = fillStyle;
}