/******************************************************************************
 * QSkinny - Copyright (C) 2016 Uwe Rathmann
 * This file may be used under the terms of the QSkinny License, Version 1.0
 *****************************************************************************/

#include "QskSpinBoxSkinlet.h"
#include "QskSpinBox.h"
#include <QFontMetrics>
#include <array>

namespace
{
    inline QPointF cursorPosSkinHint( const QskSpinBox& spinbox )
    {
        const auto aspect = QskSpinBox::Layout | QskAspect::Metric | QskAspect::Position;
        return spinbox.effectiveSkinHint( aspect ).toPointF();
    }

    enum SampleIndeces
    {
        Dec = 0,
        Txt = 1,
        Inc = 2,
        Count
    };
}

QskSpinBoxSkinlet::QskSpinBoxSkinlet( QskSkin* )
{
    setNodeRoles(
        { IncrementPanel, IncrementText, DecrementPanel, DecrementText, TextPanel, TextText } );
}

int QskSpinBoxSkinlet::sampleCount( const QskSkinnable*, QskAspect::Subcontrol ) const
{
    return 1;
}

QRectF QskSpinBoxSkinlet::sampleRect( const QskSkinnable* const skinnable, const QRectF& rect,
    QskAspect::Subcontrol subControl, int index ) const
{
    if ( index == Dec || index == Inc || index == Txt )
    {
        return subControlRect( skinnable, rect, subControl );
    }

    return Inherited::sampleRect( skinnable, rect, subControl, index );
}

QskAspect::States QskSpinBoxSkinlet::sampleStates(
    const QskSkinnable* const skinnable, QskAspect::Subcontrol subControl, int index ) const
{
    using S = QskSpinBox;
    auto states = Inherited::sampleStates( skinnable, subControl, index );

    if ( subControl == S::DecrementPanel || subControl == S::IncrementPanel ||
         subControl == S::TextPanel )
    {
        const auto* const spinbox = static_cast< const S* >( skinnable );
        const auto cursorPos = cursorPosSkinHint( *spinbox );
        const QPointF cursorPosAbs{ qAbs( cursorPos.x() ), qAbs( cursorPos.y() ) };
        const auto focusIndex = spinbox->focusIndex();
        const auto subControlRect = spinbox->subControlRect( subControl );

        const auto contain = !cursorPosAbs.isNull() && subControlRect.contains( cursorPosAbs );
        const auto pressed = contain && ( cursorPos.x() < 0 || cursorPos.y() < 0 );
        const auto hovered = contain && !pressed;
        const auto focused = ( subControl == S::IncrementPanel && focusIndex == S::Increment ) ||
                             ( subControl == S::DecrementPanel && focusIndex == S::Decrement ) ||
                             ( subControl == S::TextPanel && focusIndex == S::Textbox );

        states.setFlag( QskControl::Hovered, hovered );
        states.setFlag( QskSpinBox::Pressed, pressed );
        states.setFlag( QskControl::Focused, focused );
    }

    return states;
}

QSizeF QskSpinBoxSkinlet::sizeHint(
    const QskSkinnable* const skinnable, Qt::SizeHint sizeHint, const QSizeF& size ) const
{
    using S = QskSpinBox;
    const auto* const spinbox = static_cast< const S* >( skinnable );
    const auto layout = spinbox->alignmentHint( S::Layout );
    const auto spacing = spinbox->spacingHint( S::Layout );

    const auto strutInc = spinbox->strutSizeHint( S::IncrementPanel );
    const auto strutDec = spinbox->strutSizeHint( S::DecrementPanel );
    const auto strutTxt = spinbox->strutSizeHint( S::TextPanel );

    if ( sizeHint == Qt::MinimumSize || sizeHint == Qt::MaximumSize || Qt::PreferredSize )
    {
        if ( layout == Qt::AlignTop || layout == Qt::AlignBottom || layout == Qt::AlignVCenter )
        {
            const auto w = qMax( strutDec.width(), qMax( strutTxt.width(), strutInc.width() ) );
            const auto h = strutDec.height() + strutTxt.height() + strutInc.height();
            return { w, h + 2.0 * spacing };
        }
        if ( layout == Qt::AlignLeft || layout == Qt::AlignRight || layout == Qt::AlignHCenter )
        {
            const auto w = strutDec.width() + strutTxt.width() + strutInc.width();
            const auto h = qMax( strutDec.height(), qMax( strutTxt.height(), strutInc.height() ) );
            return { w + 2.0 * spacing, h };
        }
        if ( layout == ( Qt::AlignLeft | Qt::AlignVCenter ) ||
             layout == ( Qt::AlignRight | Qt::AlignVCenter ) )
        {
            const auto w = strutTxt.width() + qMax( strutInc.width(), strutDec.width() );
            const auto h =
                qMax( 2.0 * qMax( strutInc.height(), strutDec.height() ), strutTxt.height() );
            return { w + spacing, h + spacing };
        }
        if ( layout == ( Qt::AlignTop | Qt::AlignHCenter ) ||
             layout == ( Qt::AlignTop | Qt::AlignHCenter ) )
        {
            const auto w = qMax( strutTxt.width(), strutInc.width() + strutDec.width() );
            const auto h = strutTxt.height() + qMax( strutInc.height(), strutDec.height() );
            return { w + spacing, h + spacing };
        }
    }
    return Inherited::sizeHint( skinnable, sizeHint, size );
}

QRectF QskSpinBoxSkinlet::subControlRect( const QskSkinnable* const skinnable, const QRectF& rect,
    QskAspect::Subcontrol subControl ) const
{
    using S = QskSpinBox;

    if ( subControl == S::DecrementText )
    {
        return subControlRect( skinnable, rect, S::DecrementPanel );
    }
    if ( subControl == S::IncrementText )
    {
        return subControlRect( skinnable, rect, S::IncrementPanel );
    }
    if ( subControl == S::Text )
    {
        return subControlRect( skinnable, rect, S::TextPanel );
    }

    const auto* const spinbox = static_cast< const S* >( skinnable );
    const auto layout = spinbox->alignmentHint( S::Layout );
    const auto spacing = spinbox->spacingHint( S::Layout );

    std::array< QRectF, Count > rects = {
        QRectF{ QPointF{}, spinbox->strutSizeHint( S::DecrementPanel ) },
        QRectF{ QPointF{}, spinbox->strutSizeHint( S::TextPanel ) },
        QRectF{ QPointF{}, spinbox->strutSizeHint( S::IncrementPanel ) },
    };

    const auto center = rect.center();

    if ( layout == Qt::AlignLeft )
    {
        rects[ Txt ].moveTopLeft( { 0.0, center.y() - rects[ Txt ].height() * 0.5 } );
        rects[ Dec ].moveTopLeft(
            { rects[ Txt ].right() + spacing, center.y() - rects[ Dec ].height() * 0.5 } );
        rects[ Inc ].moveTopLeft(
            { rects[ Dec ].right() + spacing, center.y() - rects[ Inc ].height() * 0.5 } );
    }
    else if ( layout == Qt::AlignRight )
    {
        rects[ Dec ].moveTopLeft( { 0.0, center.y() - rects[ Dec ].height() * 0.5 } );
        rects[ Inc ].moveTopLeft(
            { rects[ Dec ].right() + spacing, center.y() - rects[ Inc ].height() * 0.5 } );
        rects[ Txt ].moveTopLeft(
            { rects[ Inc ].right() + spacing, center.y() - rects[ Txt ].height() * 0.5 } );
    }
    else if ( layout == Qt::AlignTop )
    {
        rects[ Txt ].moveTopLeft( { center.x() - rects[ Txt ].width() * 0.5, 0.0 } );
        rects[ Inc ].moveTopLeft(
            { center.x() - rects[ Inc ].width() * 0.5, rects[ Txt ].bottom() + spacing } );
        rects[ Dec ].moveTopLeft(
            { center.x() - rects[ Dec ].width() * 0.5, rects[ Inc ].bottom() + spacing } );
    }
    else if ( layout == Qt::AlignBottom )
    {
        rects[ Inc ].moveTopLeft( { center.x() - rects[ Inc ].width() * 0.5, 0.0 } );
        rects[ Dec ].moveTopLeft(
            { center.x() - rects[ Dec ].width() * 0.5, rects[ Inc ].bottom() + spacing } );
        rects[ Txt ].moveTopLeft(
            { center.x() - rects[ Txt ].width() * 0.5, rects[ Dec ].bottom() + spacing } );
    }
    else if ( layout == Qt::AlignHCenter )
    {
        rects[ Dec ].moveTopLeft( { 0.0, center.y() - rects[ Dec ].height() * 0.5 } );
        rects[ Txt ].moveTopLeft(
            { rects[ Dec ].right() + spacing, center.y() - rects[ Txt ].height() * 0.5 } );
        rects[ Inc ].moveTopLeft(
            { rects[ Txt ].right() + spacing, center.y() - rects[ Inc ].height() * 0.5 } );
    }
    else if ( layout == Qt::AlignVCenter )
    {
        rects[ Inc ].moveTopLeft( { center.x() - rects[ Inc ].width() * 0.5, 0.0 } );
        rects[ Txt ].moveTopLeft(
            { center.x() - rects[ Txt ].width() * 0.5, rects[ Inc ].bottom() + spacing } );
        rects[ Dec ].moveTopLeft(
            { center.x() - rects[ Dec ].width() * 0.5, rects[ Txt ].bottom() + spacing } );
    }
    else if ( layout == ( Qt::AlignLeft | Qt::AlignVCenter ) )
    {
        rects[ Txt ].moveTopLeft( { 0.0, center.y() - rects[ Txt ].height() * 0.5 } );
        rects[ Inc ].moveTopLeft( { rects[ Txt ].right() + spacing,
            center.y() - spacing * 0.5 - rects[ Inc ].height() } );
        rects[ Dec ].moveTopLeft( { rects[ Txt ].right() + spacing, center.y() + spacing * 0.5 } );
    }
    else if ( layout == ( Qt::AlignRight | Qt::AlignVCenter ) )
    {
        const auto dx = qMax( rects[ Inc ].width(), rects[ Dec ].width() );
        rects[ Inc ].moveTopLeft(
            { dx - rects[ Inc ].width(), center.y() - spacing * 0.5 - rects[ Inc ].height() } );
        rects[ Dec ].moveTopLeft( { dx - rects[ Dec ].width(), center.y() + spacing * 0.5 } );
        rects[ Txt ].moveTopLeft( { dx + spacing, center.y() - rects[ Txt ].height() * 0.5 } );
    }
    else if ( layout == ( Qt::AlignTop | Qt::AlignHCenter ) )
    {
        rects[ Txt ].moveTopLeft( { center.x() - rects[ Txt ].width() * 0.5, 0.0 } );
        rects[ Dec ].moveTopLeft(
            { rects[ Txt ].center().x() - spacing * 0.5 - rects[ Dec ].width(),
                rects[ Txt ].bottom() + spacing } );
        rects[ Inc ].moveTopLeft(
            { rects[ Txt ].center().x() + spacing * 0.5, rects[ Txt ].bottom() + spacing } );
    }
    else if ( layout == ( Qt::AlignBottom | Qt::AlignHCenter ) )
    {
        rects[ Txt ].moveTopLeft(
            { center.x() - rects[ Txt ].width() * 0.5, center.y() - rects[ Txt ].height() * 0.5 } );
        rects[ Dec ].moveTopLeft( { center.x() - spacing * 0.5 - rects[ Dec ].width(),
            rects[ Txt ].top() - spacing - rects[ Dec ].height() } );
        rects[ Inc ].moveTopLeft(
            { center.x() + spacing * 0.5, rects[ Txt ].top() - spacing - rects[ Inc ].height() } );
    }

    if ( subControl == S::DecrementPanel )
    {
        return rects[ Dec ];
    }
    if ( subControl == S::TextPanel )
    {
        return rects[ Txt ];
    }
    if ( subControl == S::IncrementPanel )
    {
        return rects[ Inc ];
    }

    return Inherited::subControlRect( skinnable, rect, subControl );
}

QSGNode* QskSpinBoxSkinlet::updateSubNode(
    const QskSkinnable* const skinnable, const quint8 nodeRole, QSGNode* const node ) const
{
    using S = QskSpinBox;
    if ( nodeRole == IncrementPanel )
    {
        return updateSeriesNode( skinnable, S::IncrementPanel, node );
    }
    if ( nodeRole == DecrementPanel )
    {
        return updateSeriesNode( skinnable, S::DecrementPanel, node );
    }
    if ( nodeRole == IncrementText )
    {
        return updateTextNode( skinnable, node, QStringLiteral( "+" ), S::IncrementText );
    }
    if ( nodeRole == DecrementText )
    {
        return updateTextNode( skinnable, node, QStringLiteral( "-" ), S::DecrementText );
    }
    if ( nodeRole == TextPanel )
    {
        return updateSeriesNode( skinnable, S::TextPanel, node );
    }
    if ( nodeRole == TextText )
    {
        const auto* const spinbox = static_cast< const S* >( skinnable );
        return updateTextNode( skinnable, node, QString::number( spinbox->value() ), S::Text );
    }
    return Inherited::updateSubNode( skinnable, nodeRole, node );
}

QSGNode* QskSpinBoxSkinlet::updateSampleNode( const QskSkinnable* const skinnable,
    QskAspect::Subcontrol subControl, const int index, QSGNode* const node ) const
{
    using S = QskSpinBox;
    const auto* const spinbox = static_cast< const S* >( skinnable );

    if ( subControl == S::DecrementPanel || subControl == S::IncrementPanel ||
         subControl == S::TextPanel )
    {
        const auto rect = sampleRect( spinbox, spinbox->contentsRect(), subControl, index );
        return updateBoxNode( skinnable, node, rect, subControl );
    }

    return Inherited::updateSampleNode( skinnable, subControl, index, node );
}