/////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2011-     Statoil ASA
//  Copyright (C) 2013-     Ceetron Solutions AS
//  Copyright (C) 2011-2012 Ceetron 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 "RiuGridStatisticsHistogramWidget.h"

#include <QPainter>

#include <cmath>

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
RiuGridStatisticsHistogramWidget::RiuGridStatisticsHistogramWidget( QWidget* parent /*= 0*/, Qt::WindowFlags f /*= 0*/ )
    : QWidget( parent, f )
{
    m_minPercentile     = HUGE_VAL;
    m_maxPercentile     = HUGE_VAL;
    m_mean              = HUGE_VAL;
    m_min               = HUGE_VAL;
    m_max               = -HUGE_VAL;
    m_maxHistogramCount = 0;

    m_width  = 0;
    m_height = 0;
    m_x      = 0;
    m_y      = 0;
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiuGridStatisticsHistogramWidget::paintEvent( QPaintEvent* event )
{
    QPainter painter( this );
    this->draw( &painter, 0, 0, this->width() - 1, this->height() - 1 );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiuGridStatisticsHistogramWidget::draw( QPainter* painter, int x, int y, int width, int height )
{
    // Initialize variables
    m_x      = x;
    m_y      = y;
    m_width  = width;
    m_height = height;

    QRect r1( x, y, width, height );

    // Frame around it all;
    QColor frameColor      = palette().color( QPalette::WindowText ); // QColor(220, 240, 255, 100);
    QColor foregroundColor = palette().color( QPalette::Dark ); // QColor(100, 141, 189);

    painter->setPen( frameColor );
    painter->drawRect( r1 );

    // Columns
    painter->setPen( foregroundColor );

    int yColBottom = yPosFromCount( 0 );

    for ( size_t colIdx = 0; colIdx < m_histogramData.size(); ++colIdx )
    {
        size_t colCount  = m_histogramData[colIdx];
        int    yColTop   = yPosFromCount( colCount );
        int    xColStart = xPosFromColIdx( colIdx );
        int    xColEnd   = xPosFromColIdx( colIdx + 1 );

        // First line
        painter->drawLine( xColStart, yColBottom, xColStart, yColTop );
        // If we span more than one pixel with :
        ++xColStart;
        for ( ; xColStart < xColEnd; ++xColStart )
        {
            painter->drawLine( xColStart, yColBottom, xColStart, yColTop );
        }
    }

    // Vertical lines for percentiles
    if ( m_minPercentile != HUGE_VAL )
    {
        int xpos = xPosFromDomainValue( m_minPercentile );
        painter->setPen( QColor( 255, 0, 0, 200 ) );
        painter->drawLine( xpos, y + 1, xpos, y + height - 1 );
    }

    // Vertical lines for percentiles
    if ( m_maxPercentile != HUGE_VAL )
    {
        int xpos = xPosFromDomainValue( m_maxPercentile );
        painter->setPen( QColor( 255, 0, 0, 200 ) );
        painter->drawLine( xpos, y + 1, xpos, y + height - 1 );
    }

    // Vertical lines for percentiles
    if ( m_mean != HUGE_VAL )
    {
        int xpos = xPosFromDomainValue( m_mean );
        painter->setPen( QColor( 0, 0, 255, 200 ) );
        painter->drawLine( xpos, y + 1, xpos, y + height - 1 );
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiuGridStatisticsHistogramWidget::setHistogramData( double min, double max, const std::vector<size_t>& histogram )
{
    m_min           = min;
    m_max           = max;
    m_histogramData = histogram;

    m_maxHistogramCount = 0;
    for ( size_t colIdx = 0; colIdx < m_histogramData.size(); ++colIdx )
    {
        if ( m_maxHistogramCount < m_histogramData[colIdx] ) m_maxHistogramCount = m_histogramData[colIdx];
    }
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void RiuGridStatisticsHistogramWidget::setPercentiles( double pmin, double pmax )
{
    m_minPercentile = pmin;
    m_maxPercentile = pmax;
}

#define xBorder 1
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
int RiuGridStatisticsHistogramWidget::xPosFromColIdx( size_t colIdx )
{
    return (int)( m_x + xBorder + ( m_width - 2 * xBorder ) * colIdx / m_histogramData.size() );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
int RiuGridStatisticsHistogramWidget::xPosFromDomainValue( double value )
{
    double range = m_max - m_min;
    return ( range == 0.0 ) ? (int)( m_x + xBorder )
                            : (int)( m_x + xBorder + ( m_width - 2 * xBorder ) * ( value - m_min ) / ( m_max - m_min ) );
}

//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
int RiuGridStatisticsHistogramWidget::yPosFromCount( size_t colHeight )
{
    return (int)( m_y + m_height - 1 - ( m_height - 3 ) * colHeight / m_maxHistogramCount );
}