/******************************************************************************
 * Copyright (C) 2021 Edelhirsch Software GmbH
 * This file may be used under the terms of the 3-clause BSD License
 *****************************************************************************/

#include "PieChartPainted.h"

#include <QskAnimator.h>
#include <QskBox.h>
#include <QskRgbValue.h>
#include <QskSetup.h>
#include <QskSkin.h>
#include <QskTextLabel.h>
#include <QskFunctions.h>

#include <QFontMetricsF>
#include <QGuiApplication>
#include <QQuickPaintedItem>
#include <QQuickWindow>

QSK_SUBCONTROL( PieChartPainted, Panel )

namespace
{
    QColor invertedColor( const QColor& c )
    {
        QColor ret = { 255 - c.red(), 255 - c.green(), 255 - c.blue()};
        return ret;
    }
}

// ### There must be an easier way to do this
class ProgressBarAnimator : public QskAnimator
{
  public:
    ProgressBarAnimator( PieChartPainted* pieChart, CircularProgressBar* progressBar )
        : m_pieChart( pieChart )
        , m_progressBar( progressBar )
    {
        QQuickWindow* w = static_cast< QQuickWindow* >( qGuiApp->allWindows().at( 0 ) );
        setWindow( w );
        setDuration( 500 );
        setEasingCurve( QEasingCurve::Linear );
        setAutoRepeat( false );
    }

    void setup() override
    {
        m_backgroundColor = m_pieChart->color( PieChartPainted::Panel );
    }

    void advance( qreal value ) override
    {
        const QColor c = m_backgroundColor;
        const QColor c2 = invertedColor( c );
        const QColor newColor = QskRgb::interpolated( c2, c, value );
        m_progressBar->setBackgroundColor( newColor );

        QRadialGradient gradient = m_ringGradient;
        QRadialGradient newGradient = gradient;

        for( const QGradientStop& stop : gradient.stops() )
        {
            QColor c = stop.second;
            QColor c2 = invertedColor( c );
            const QColor newColor = QskRgb::interpolated( c, c2, value );
            newGradient.setColorAt( stop.first, newColor );
        }

        m_progressBar->update();
    }

  private:
    QColor m_backgroundColor;
    QRadialGradient m_ringGradient;
    PieChartPainted* m_pieChart;
    CircularProgressBar* m_progressBar;
};

PieChartPainted::PieChartPainted( const QColor& color, const QskGradient& gradient, int progress, int /*value*/, QQuickItem* parent )
    : QskControl( parent )
    , m_color( color )
    , m_gradient( gradient )
    , m_progressBar( new CircularProgressBar( this ) )
    , m_progressLabel( new QskTextLabel( this ) )
    , m_animator( new ProgressBarAnimator( this, m_progressBar ) )
{
    setAutoLayoutChildren( true );
    setSubcontrolProxy( QskBox::Panel, PieChartPainted::Panel );

    m_progressBar->setGradientHint( CircularProgressBar::Bar, gradient );
    m_progressBar->setValue( progress );

    auto progressText = QString::number( progress ) + " %";
    m_progressLabel->setText( progressText );
    m_progressLabel->setFontRole( QskSkin::SmallFont );
    m_progressLabel->setTextColor( color );

    const QColor c = this->color( Panel );
    m_progressBar->setBackgroundColor( c );

    connect( qskSetup, &QskSetup::skinChanged,
        [this]() { m_animator->start(); } );
}

QSizeF PieChartPainted::contentsSizeHint( Qt::SizeHint, const QSizeF& ) const
{
    return {57, 57};
}

void PieChartPainted::updateLayout()
{
    m_progressBar->update();

    const auto rect = layoutRect();

    QFontMetricsF fm( m_progressLabel->effectiveFont( QskTextLabel::Text ) );
    auto textWidth = qskHorizontalAdvance( fm, m_progressLabel->text() );
    auto posX = rect.width() / 2 - textWidth / 2;
    auto posY = rect.height() / 2 - fm.height() / 2;

    m_progressLabel->setPosition( posX, posY );
    m_progressLabel->setFixedWidth( textWidth );
}