/////////////////////////////////////////////////////////////////////////////////
//
//  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 "RiuLineSegmentQwtPlotCurve.h"

#include "qwt_symbol.h"
#include "RigCurveDataTools.h"
#include "qwt_date.h"
#include "qwt_point_mapper.h"
#include "qwt_painter.h"


//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
RiuLineSegmentQwtPlotCurve::RiuLineSegmentQwtPlotCurve(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;
}

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

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

    QPolygonF points;
    std::vector< std::pair<size_t, size_t> > filteredIntervals;
    {
        std::vector<double> filteredYValues;
        std::vector<double> filteredXValues;

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

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

            filteredIntervals = RigCurveDataTools::computePolyLineStartStopIndices(intervalsOfValidValues);
        }

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

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

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

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

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
void RiuLineSegmentQwtPlotCurve::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 RiuLineSegmentQwtPlotCurve::drawSymbols(QPainter *painter, const QwtSymbol &symbol, 
                                            const QwtScaleMap &xMap, const QwtScaleMap &yMap, 
                                            const QRectF &canvasRect, int from, int to) const
{
    if (m_symbolSkipPixelDistance <= 0)
    {
        QwtPlotCurve::drawSymbols(painter, symbol, xMap, yMap, canvasRect, from, to);
        return;
    }

    QwtPointMapper mapper;
    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 filteredPoints;
    QPointF lastDrawnSymbolPos;

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

    if(pointCount > 1) filteredPoints.push_back(points.back());


    if(filteredPoints.size() > 0)
        symbol.drawSymbols(painter, filteredPoints);
}

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

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

//--------------------------------------------------------------------------------------------------
/// 
//--------------------------------------------------------------------------------------------------
std::vector<double> RiuLineSegmentQwtPlotCurve::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> RiuLineSegmentQwtPlotCurve::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;
}