/////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2015-     Statoil ASA
//  Copyright (C) 2015-     Ceetron Solutions AS
// 
//  ResInsight 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.
// 
//  ResInsight 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 at <http://www.gnu.org/licenses/gpl.html> 
//  for more details.
//
/////////////////////////////////////////////////////////////////////////////////

#include "RiuQwtPlotCurve.h"

#include "RiaCurveDataTools.h"
#include "RiuQwtSymbol.h"

#include "qwt_symbol.h"
#include "qwt_date.h"
#include "qwt_point_mapper.h"
#include "qwt_painter.h"
#include "qwt_plot_intervalcurve.h"
#include "qwt_scale_map.h"
#include "qwt_interval_symbol.h"

#include <limits>

//--------------------------------------------------------------------------------------------------
/// Internal constants
//--------------------------------------------------------------------------------------------------
#define DOUBLE_INF  std::numeric_limits<double>::infinity()

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
RiuQwtPlotCurve::RiuQwtPlotCurve(const QString &title)
    : QwtPlotCurve(title)
{
    this->setLegendAttribute(QwtPlotCurve::LegendShowLine, true);
    this->setLegendAttribute(QwtPlotCurve::LegendShowSymbol, true);
    this->setLegendAttribute(QwtPlotCurve::LegendShowBrush, true);

    this->setRenderHint(QwtPlotItem::RenderAntialiased, true);

    m_symbolSkipPixelDistance = 10.0f;

    m_errorBars = new QwtPlotIntervalCurve();
    m_errorBars->setStyle(QwtPlotIntervalCurve::CurveStyle::NoCurve);
    m_errorBars->setSymbol(new QwtIntervalSymbol(QwtIntervalSymbol::Bar));
    m_errorBars->setItemAttribute(QwtPlotItem::Legend, false);
    m_errorBars->setZ(Z_ERROR_BARS);

    m_showErrorBars = true;
    m_attachedToPlot = nullptr;
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
RiuQwtPlotCurve::~RiuQwtPlotCurve()
{
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setSamplesFromXValuesAndYValues(const std::vector<double>& xValues, const std::vector<double>& yValues, const std::vector<double>& yErrorValues, bool keepOnlyPositiveValues)
{
    CVF_ASSERT(xValues.size() == yValues.size());
    CVF_ASSERT(yErrorValues.empty() || yErrorValues.size() == xValues.size());

    bool showErrorBars = m_showErrorBars && !yErrorValues.empty();
    QPolygonF points;
    QVector<QwtIntervalSample> errorIntervals;
    std::vector< std::pair<size_t, size_t> > filteredIntervals;
    {
        std::vector<double> filteredYValues;
        std::vector<double> filteredXValues;
        std::vector<double> filteredYErrorValues;

        {
            auto intervalsOfValidValues = RiaCurveDataTools::calculateIntervalsOfValidValues(yValues, keepOnlyPositiveValues);

            RiaCurveDataTools::getValuesByIntervals(yValues, intervalsOfValidValues, &filteredYValues);
            RiaCurveDataTools::getValuesByIntervals(xValues, intervalsOfValidValues, &filteredXValues);

            if(showErrorBars) RiaCurveDataTools::getValuesByIntervals(yErrorValues, intervalsOfValidValues, &filteredYErrorValues);

            filteredIntervals = RiaCurveDataTools::computePolyLineStartStopIndices(intervalsOfValidValues);
        }

        points.reserve(static_cast<int>(filteredXValues.size()));
        errorIntervals.reserve(static_cast<int>(filteredXValues.size()));
        for ( size_t i = 0; i < filteredXValues.size(); i++ )
        {
            points << QPointF(filteredXValues[i], filteredYValues[i]);

            if (showErrorBars && filteredYValues[i] != DOUBLE_INF && filteredYErrorValues[i] != DOUBLE_INF)
            {
                errorIntervals << QwtIntervalSample(filteredXValues[i], filteredYValues[i] - filteredYErrorValues[i], filteredYValues[i] + filteredYErrorValues[i]);
            }
        }
    }

    this->setSamples(points);
    this->setLineSegmentStartStopIndices(filteredIntervals);

    if(showErrorBars) m_errorBars->setSamples(errorIntervals);
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setSamplesFromXValuesAndYValues(const std::vector<double>& xValues, const std::vector<double>& yValues, bool keepOnlyPositiveValues)
{
    setSamplesFromXValuesAndYValues(xValues, yValues, std::vector<double>(), keepOnlyPositiveValues);
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setSamplesFromDatesAndYValues(const std::vector<QDateTime>& dateTimes, const std::vector<double>& yValues, bool keepOnlyPositiveValues)
{
    setSamplesFromXValuesAndYValues(RiuQwtPlotCurve::fromQDateTime(dateTimes), yValues, std::vector<double>(), keepOnlyPositiveValues);
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setSamplesFromTimeTAndYValues(const std::vector<time_t>& dateTimes, const std::vector<double>& yValues, bool keepOnlyPositiveValues)
{
    setSamplesFromXValuesAndYValues(RiuQwtPlotCurve::fromTime_t(dateTimes), yValues, std::vector<double>(), keepOnlyPositiveValues);
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setSamplesFromTimeTAndYValues(const std::vector<time_t>& dateTimes, const std::vector<double>& yValues, const std::vector<double>& yErrorValues, bool keepOnlyPositiveValues)
{
    setSamplesFromXValuesAndYValues(RiuQwtPlotCurve::fromTime_t(dateTimes), yValues, yErrorValues, keepOnlyPositiveValues);
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::drawCurve(QPainter* p, int style,
    const QwtScaleMap& xMap, const QwtScaleMap& yMap,
    const QRectF& canvasRect, int from, int to) const
{
    size_t intervalCount = m_polyLineStartStopIndices.size();
    if (intervalCount > 0)
    {
        for (size_t intIdx = 0; intIdx < intervalCount; intIdx++)
        {
            if (m_polyLineStartStopIndices[intIdx].first == m_polyLineStartStopIndices[intIdx].second)
            {
                // Use a symbol to draw a single value, as a single value will not be visible
                // when using QwtPlotCurve::drawCurve without symbols activated

                QwtSymbol symbol(QwtSymbol::XCross);
                symbol.setSize(10, 10);

                QwtPlotCurve::drawSymbols(p, symbol, xMap, yMap, canvasRect, (int) m_polyLineStartStopIndices[intIdx].first, (int) m_polyLineStartStopIndices[intIdx].second);
            }
            else
            {
                QwtPlotCurve::drawCurve(p, style, xMap, yMap, canvasRect, (int) m_polyLineStartStopIndices[intIdx].first, (int) m_polyLineStartStopIndices[intIdx].second);
            }
        }
    }
    else
    {
        QwtPlotCurve::drawCurve(p, style, xMap, yMap, canvasRect, from, to);
    }
};

//--------------------------------------------------------------------------------------------------
/// Drawing symbols but skipping if they are to close to the previous one
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::drawSymbols(QPainter *painter, const QwtSymbol &symbol, 
                                            const QwtScaleMap &xMap, const QwtScaleMap &yMap, 
                                            const QRectF &canvasRect, int from, int to) const
{
    QwtPointMapper mapper;
    bool filterSymbols = m_symbolSkipPixelDistance > 0;

    if (filterSymbols)
    {
        mapper.setFlag(QwtPointMapper::RoundPoints,
                       QwtPainter::roundingAlignment(painter));
        mapper.setFlag(QwtPointMapper::WeedOutPoints,
                       testPaintAttribute(QwtPlotCurve::FilterPoints));
        mapper.setBoundingRect(canvasRect);
    }

    const QPolygonF points = mapper.toPointsF(xMap, yMap, data(), from, to);
    int pointCount = points.size();
    QPolygonF pointsToDisplay;

    if (filterSymbols)
    {
        QPointF lastDrawnSymbolPos;

        if (pointCount > 0)
        {
            pointsToDisplay.push_back(points[0]);
            lastDrawnSymbolPos = points[0];
        }

        float sqSkipDist = m_symbolSkipPixelDistance * m_symbolSkipPixelDistance;

        for (int pIdx = 1; pIdx < pointCount - 1; ++pIdx)
        {
            QPointF diff = points[pIdx] - lastDrawnSymbolPos;
            float sqDistBetweenSymbols = diff.x()*diff.x() + diff.y()*diff.y();

            if (sqDistBetweenSymbols > sqSkipDist)
            {
                pointsToDisplay.push_back(points[pIdx]);
                lastDrawnSymbolPos = points[pIdx];
            }
        }

        if (pointCount > 1) pointsToDisplay.push_back(points.back());
    }
    else
    {
        pointsToDisplay = points;
    }


    if (pointsToDisplay.size() > 0)
    {
        symbol.drawSymbols(painter, pointsToDisplay);

        const RiuQwtSymbol* sym = dynamic_cast<const RiuQwtSymbol*>(&symbol);

        if (sym && !sym->label().isEmpty())
        {
            for (auto& pt : pointsToDisplay)
            {
                sym->renderSymbolLabel(painter, pt);
            }
        }
    }
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setLineSegmentStartStopIndices(const std::vector< std::pair<size_t, size_t> >& lineSegmentStartStopIndices)
{
    m_polyLineStartStopIndices = lineSegmentStartStopIndices;
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setSymbolSkipPixelDistance(float distance)
{
    m_symbolSkipPixelDistance = distance >= 0.0f ? distance: 0.0f;
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::attach(QwtPlot *plot)
{
    QwtPlotItem::attach(plot);
    if(m_showErrorBars) m_errorBars->attach(plot);
    m_attachedToPlot = plot;
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::detach()
{
    QwtPlotItem::detach();
    m_errorBars->detach();
    m_attachedToPlot = nullptr;
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::clearErrorBars()
{
    m_errorBars->setSamples(nullptr);
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::showErrorBars(bool show)
{
    m_showErrorBars = show;
    if (m_showErrorBars && m_attachedToPlot)    m_errorBars->attach(m_attachedToPlot);
    else                                        m_errorBars->detach();
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setErrorBarsColor(QColor color)
{
    QwtIntervalSymbol* newSymbol = new QwtIntervalSymbol(QwtIntervalSymbol::Bar);
    newSymbol->setPen(QPen(color));
    m_errorBars->setSymbol(newSymbol);
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiuQwtPlotCurve::setAppearance(LineStyleEnum          lineStyle,
                                               CurveInterpolationEnum interpolationType,
                                               int                    curveThickness,
                                               const QColor&          curveColor)
{
    QwtPlotCurve::CurveStyle curveStyle = QwtPlotCurve::NoCurve;
    Qt::PenStyle penStyle = Qt::SolidLine;

    if (lineStyle != STYLE_NONE)
    {
        switch (interpolationType)
        {
        case INTERPOLATION_STEP_LEFT:
            curveStyle = QwtPlotCurve::Steps;
            setCurveAttribute(QwtPlotCurve::Inverted, false);
            break;
        case INTERPOLATION_POINT_TO_POINT: // Fall through
        default:
            curveStyle = QwtPlotCurve::Lines;
            break;
        }

        switch (lineStyle)
        {
        case STYLE_SOLID:
            penStyle = Qt::SolidLine;
            break;
        case STYLE_DASH:
            penStyle = Qt::DashLine;
            break;
        case STYLE_DOT:
            penStyle = Qt::DotLine;
            break;
        case STYLE_DASH_DOT:
            penStyle = Qt::DashDotLine;
            break;

        default:
            break;
        }
    }
    QPen curvePen(curveColor);
    curvePen.setWidth(curveThickness);
    curvePen.setStyle(penStyle);

    setPen(curvePen);
    setStyle(curveStyle);
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
std::vector<double> RiuQwtPlotCurve::fromQDateTime(const std::vector<QDateTime>& dateTimes)
{
    std::vector<double> doubleValues;

    if (!dateTimes.empty())
    {
        doubleValues.reserve(dateTimes.size());

        for (const auto& dt : dateTimes)
        {
            doubleValues.push_back(QwtDate::toDouble(dt));
        }
    }

    return doubleValues;
}

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
std::vector<double> RiuQwtPlotCurve::fromTime_t(const std::vector<time_t>& timeSteps)
{
    std::vector<double> doubleValues;

    if (!timeSteps.empty())
    {
        doubleValues.reserve(timeSteps.size());
        for (const auto& time : timeSteps)
        {
            double milliSecSinceEpoch = time * 1000; // This is kind of hack, as the c++ standard does not state what time_t is. "Almost always" secs since epoch according to cppreference.com
        
            doubleValues.push_back(milliSecSinceEpoch);
        }
    }

    return doubleValues;
}