/***************************************************************************
 *   Copyright (C) 2004-2005 by Enrico Ros <eros.kde@email.it>             *
 *   Copyright (C) 2017    Klarälvdalens Datakonsult AB, a KDAB Group      *
 *                         company, info@kdab.com. Work sponsored by the   *
 *                         LiMux project of the city of Munich             *
 *                                                                         *
 *   This program 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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 ***************************************************************************/

#include "pageviewutils.h"

// qt/kde includes
#include <qapplication.h>
#include <qmenu.h>
#include <qpainter.h>
#include <qtimer.h>
#include <kiconloader.h>

// local includes
#include "formwidgets.h"
#include "videowidget.h"
#include "core/page.h"
#include "core/form.h"
#include "settings.h"

/*********************/
/** PageViewItem     */
/*********************/

PageViewItem::PageViewItem( const Okular::Page * page )
    : m_page( page ), m_zoomFactor( 1.0 ), m_visible( true ),
    m_formsVisible( false ), m_crop( 0., 0., 1., 1. )
{
}

PageViewItem::~PageViewItem()
{
    qDeleteAll( m_formWidgets );
    qDeleteAll( m_videoWidgets );
}

const Okular::Page * PageViewItem::page() const
{
    return m_page;
}

int PageViewItem::pageNumber() const
{
    return m_page->number();
}

const QRect& PageViewItem::croppedGeometry() const
{
    return m_croppedGeometry;
}

int PageViewItem::croppedWidth() const
{
    return m_croppedGeometry.width();
}

int PageViewItem::croppedHeight() const
{
    return m_croppedGeometry.height();
}

const QRect& PageViewItem::uncroppedGeometry() const
{
    return m_uncroppedGeometry;
}

int PageViewItem::uncroppedWidth() const
{
    return m_uncroppedGeometry.width();
}

int PageViewItem::uncroppedHeight() const
{
    return m_uncroppedGeometry.height();
}

const Okular::NormalizedRect & PageViewItem::crop() const
{
    return m_crop;
}

double PageViewItem::zoomFactor() const
{
    return m_zoomFactor;
}

double PageViewItem::absToPageX( double absX ) const
{
    return ( absX - m_uncroppedGeometry.left() ) / m_uncroppedGeometry.width();
}

double PageViewItem::absToPageY( double absY ) const
{
    return ( absY - m_uncroppedGeometry.top() ) / m_uncroppedGeometry.height();
}

bool PageViewItem::isVisible() const
{
    return m_visible;
}

QSet<FormWidgetIface*>& PageViewItem::formWidgets()
{
    return m_formWidgets;
}

QHash< Okular::Movie *, VideoWidget* >& PageViewItem::videoWidgets()
{
    return m_videoWidgets;
}

void PageViewItem::setWHZC( int w, int h, double z, const Okular:: NormalizedRect & c )
{
    m_croppedGeometry.setWidth( w );
    m_croppedGeometry.setHeight( h );
    m_zoomFactor = z;
    m_crop = c;
    m_uncroppedGeometry.setWidth( qRound( w / ( c.right - c.left ) ) );
    m_uncroppedGeometry.setHeight( qRound( h / ( c.bottom - c.top ) ) );
    for (FormWidgetIface *fwi : qAsConst(m_formWidgets))
    {
        Okular::NormalizedRect r = fwi->rect();
        fwi->setWidthHeight(
            qRound( fabs( r.right - r.left ) * m_uncroppedGeometry.width() ),
            qRound( fabs( r.bottom - r.top ) * m_uncroppedGeometry.height() ) );
    }
    for ( VideoWidget *vw : qAsConst(m_videoWidgets) )
    {
        const Okular::NormalizedRect r = vw->normGeometry();
        vw->resize(
            qRound( fabs( r.right - r.left ) * m_uncroppedGeometry.width() ),
            qRound( fabs( r.bottom - r.top ) * m_uncroppedGeometry.height() ) );
    }
}

void PageViewItem::moveTo( int x, int y )
// Assumes setWHZC() has already been called
{
    m_croppedGeometry.moveLeft( x );
    m_croppedGeometry.moveTop( y );
    m_uncroppedGeometry.moveLeft( qRound( x - m_crop.left * m_uncroppedGeometry.width() ) );
    m_uncroppedGeometry.moveTop( qRound( y - m_crop.top * m_uncroppedGeometry.height() ) );
    QSet<FormWidgetIface*>::iterator it = m_formWidgets.begin(), itEnd = m_formWidgets.end();
    for ( ; it != itEnd; ++it )
    {
        Okular::NormalizedRect r = (*it)->rect();
        (*it)->moveTo(
            qRound( x + m_uncroppedGeometry.width() * r.left ) + 1,
            qRound( y + m_uncroppedGeometry.height() * r.top ) + 1 );
    }
    for ( VideoWidget *vw : qAsConst(m_videoWidgets) )
    {
        const Okular::NormalizedRect r = vw->normGeometry();
        vw->move(
            qRound( x + m_uncroppedGeometry.width() * r.left ) + 1,
            qRound( y + m_uncroppedGeometry.height() * r.top ) + 1 );
    }
}

void PageViewItem::setVisible( bool visible )
{
    setFormWidgetsVisible( visible && m_formsVisible );
    m_visible = visible;
}

void PageViewItem::invalidate()
{
    m_croppedGeometry.setRect( 0, 0, 0, 0 );
    m_uncroppedGeometry.setRect( 0, 0, 0, 0 );
}

bool PageViewItem::setFormWidgetsVisible( bool visible )
{
    m_formsVisible = visible;

    if ( !m_visible )
        return false;

    bool somehadfocus = false;
    QSet<FormWidgetIface*>::iterator it = m_formWidgets.begin(), itEnd = m_formWidgets.end();
    for ( ; it != itEnd; ++it )
    {
        bool hadfocus = (*it)->setVisibility( visible && (*it)->formField()->isVisible() &&
                                              FormWidgetsController::shouldFormWidgetBeShown((*it)->formField()) );
        somehadfocus = somehadfocus || hadfocus;
    }
    return somehadfocus;
}

void PageViewItem::reloadFormWidgetsState()
{
    for (FormWidgetIface *fwi : qAsConst(m_formWidgets))
    {
        fwi->setVisibility( fwi->formField()->isVisible() && FormWidgetsController::shouldFormWidgetBeShown(fwi->formField()));
    }
}

/*********************/
/** PageViewMessage  */
/*********************/

PageViewMessage::PageViewMessage( QWidget * parent )
    : QWidget( parent ), m_timer( nullptr )
    , m_lineSpacing( 0 )
{
    setObjectName( QStringLiteral( "pageViewMessage" ) );
    setFocusPolicy( Qt::NoFocus );
    QPalette pal = palette();
    pal.setColor( QPalette::Active, QPalette::Window, QApplication::palette().color( QPalette::Active, QPalette::Window ) );
    setPalette( pal );
    // if the layout is LtR, we can safely place it in the right position
    if ( layoutDirection() == Qt::LeftToRight )
        move( 10, 10 );
    resize( 0, 0 );
    hide();
}

void PageViewMessage::display( const QString & message, const QString & details, Icon icon, int durationMs )
// give Caesar what belongs to Caesar: code taken from Amarok's osd.h/.cpp
// "redde (reddite, pl.) cesari quae sunt cesaris", just btw.  :)
// The code has been heavily modified since then.
{
    if ( !Okular::Settings::showOSD() )
    {
        hide();
        return;
    }

    // set text
    m_message = message;
    m_details = details;
    // reset vars
    m_lineSpacing = 0;

    // load icon (if set)
    m_symbol = QPixmap();
    const auto symbolSize = style()->pixelMetric(QStyle::PM_SmallIconSize);
    if ( icon != None )
    {
        switch ( icon )
        {
            case Annotation:
                m_symbol = QIcon::fromTheme( QStringLiteral("draw-freehand") ).pixmap( symbolSize );
                break;
            case Find:
                m_symbol = QIcon::fromTheme( QStringLiteral("zoom-original") ).pixmap( symbolSize );
                break;
            case Error:
                m_symbol = QIcon::fromTheme( QStringLiteral("dialog-error") ).pixmap( symbolSize );
                break;
            case Warning:
                m_symbol = QIcon::fromTheme( QStringLiteral("dialog-warning") ).pixmap( symbolSize );
                break;
            default:
                m_symbol = QIcon::fromTheme( QStringLiteral("dialog-information") ).pixmap( symbolSize );
                break;
        }

    }

    computeSizeAndResize();
    // show widget and schedule a repaint
    show();
    update();

    // close the message window after given mS
    if ( durationMs > 0 )
    {
        if ( !m_timer )
        {
            m_timer = new QTimer( this );
            m_timer->setSingleShot( true );
            connect(m_timer, &QTimer::timeout, this, &PageViewMessage::hide);
        }
        m_timer->start( durationMs );
    } else if ( m_timer )
        m_timer->stop();

    qobject_cast<QAbstractScrollArea*>(parentWidget())->viewport()->installEventFilter(this);

}

QRect PageViewMessage::computeTextRect( const QString & message, int extra_width ) const
// Return the QRect which embeds the text
{
    int charSize = fontMetrics().averageCharWidth();
    /* width of the viewport, minus 20 (~ size removed by further resizing),
       minus the extra size (usually the icon width), minus (a bit empirical)
       twice the mean width of a character to ensure that the bounding box is
       really smaller than the container.
     */
    const int boundingWidth = qobject_cast<QAbstractScrollArea*>(parentWidget())->viewport()->width() - 20 - ( extra_width > 0 ? 2 + extra_width : 0 ) - 2*charSize;
    QRect textRect = fontMetrics().boundingRect( 0, 0, boundingWidth, 0,
                     Qt::AlignLeft | Qt::AlignTop | Qt::TextWordWrap, message );
    textRect.translate( -textRect.left(), -textRect.top() );
    textRect.adjust( 0, 0, 2, 2 );

    return textRect;
}

void PageViewMessage::computeSizeAndResize()
{
    // determine text rectangle
    const QRect textRect = computeTextRect( m_message, m_symbol.width() );
    int width = textRect.width(),
        height = textRect.height();

    if ( !m_details.isEmpty() )
    {
        // determine details text rectangle
        const QRect detailsRect = computeTextRect( m_details, m_symbol.width() );
        width = qMax( width, detailsRect.width() );
        height += detailsRect.height();

        // plus add a ~60% line spacing
        m_lineSpacing = static_cast< int >( fontMetrics().height() * 0.6 );
        height += m_lineSpacing;
    }

    // update geometry with icon information
    if ( ! m_symbol.isNull() )
    {
        width += 2 + m_symbol.width();
        height = qMax( height, m_symbol.height() );
    }

    // resize widget
    resize( QRect( 0, 0, width + 10, height + 8 ).size() );

    // if the layout is RtL, we can move it to the right place only after we
    // know how much size it will take
    if ( layoutDirection() == Qt::RightToLeft )
        move( parentWidget()->width() - geometry().width() - 10 - 1, 10 );
}


bool PageViewMessage::eventFilter(QObject * obj, QEvent * event )
{
    /* if the parent object (scroll area) resizes, the message should
       resize as well */
    if (event->type() == QEvent::Resize)
    {
        QResizeEvent *resizeEvent = static_cast<QResizeEvent *>(event);
        if ( resizeEvent->oldSize() != resizeEvent->size() )
        {
           computeSizeAndResize();
        }
    }
    // standard event processing
    return QObject::eventFilter(obj, event);
}

void PageViewMessage::paintEvent( QPaintEvent * /* e */ )
{
    const QRect textRect = computeTextRect( m_message, m_symbol.width() );

    QRect detailsRect;
    if ( !m_details.isEmpty() )
    {
        detailsRect = computeTextRect( m_details, m_symbol.width() );
    }

    int textXOffset = 0,
        // add 2 to account for the reduced drawRoundRect later
        textYOffset = ( geometry().height() - textRect.height() - detailsRect.height() - m_lineSpacing + 2 ) / 2,
        iconXOffset = 0,
        iconYOffset = !m_symbol.isNull() ? ( geometry().height() - m_symbol.height() ) / 2 : 0,
        shadowOffset = 1;

    if ( layoutDirection() == Qt::RightToLeft )
        iconXOffset = 2 + textRect.width();
    else
        textXOffset = 2 + m_symbol.width();

    // draw background
    QPainter painter( this );
    painter.setRenderHint( QPainter::Antialiasing, true );
    painter.setPen( Qt::black );
    painter.setBrush( palette().color( QPalette::Window ) );
    painter.translate( 0.5, 0.5 );
    painter.drawRoundRect( 1, 1, width()-2, height()-2, 1600 / width(), 1600 / height() );

    // draw icon if present
    if ( !m_symbol.isNull() )
        painter.drawPixmap( 5 + iconXOffset, iconYOffset, m_symbol, 0, 0, m_symbol.width(), m_symbol.height() );

    const int xStartPoint = 5 + textXOffset;
    const int yStartPoint = textYOffset;
    const int textDrawingFlags = Qt::AlignLeft | Qt::AlignTop | Qt::TextWordWrap;

    // draw shadow and text
    painter.setPen( palette().color( QPalette::Window ).darker( 115 ) );
    painter.drawText( xStartPoint + shadowOffset, yStartPoint + shadowOffset, textRect.width(), textRect.height(), textDrawingFlags, m_message );
    if ( !m_details.isEmpty() )
        painter.drawText( xStartPoint + shadowOffset, yStartPoint + textRect.height() + m_lineSpacing + shadowOffset, textRect.width(), detailsRect.height(), textDrawingFlags, m_details );
    painter.setPen( palette().color( QPalette::WindowText ) );
    painter.drawText( xStartPoint, yStartPoint, textRect.width(), textRect.height(), textDrawingFlags, m_message );
    if ( !m_details.isEmpty() )
        painter.drawText( xStartPoint + shadowOffset, yStartPoint + textRect.height() + m_lineSpacing, textRect.width(), detailsRect.height(), textDrawingFlags, m_details );
}

void PageViewMessage::mousePressEvent( QMouseEvent * /*e*/ )
{
    if ( m_timer )
        m_timer->stop();
    hide();
}