/*
    SPDX-FileCopyrightText: 2001-2003 John Firebaugh <jfirebaugh@kde.org>
    SPDX-FileCopyrightText: 2001-2009 Otto Bruggeman <bruggie@gmail.com>
    SPDX-FileCopyrightText: 2004 Jeff Snyder <jeff@caffeinated.me.uk>
    SPDX-FileCopyrightText: 2007-2011 Kevin Kofler <kevin.kofler@chello.at>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#include "kompareconnectwidget.h"

#include <QApplication>
#include <QPainter>
#include <QPainterPath>
#include <QPixmap>
#include <QStyle>
#include <QTimer>
#include <QPaintEvent>
#include <QFrame>
#include <QMouseEvent>
#include <QDebug>

#include "viewsettings.h"
#include "komparelistview.h"
#include "komparesplitter.h"

using namespace KompareDiff2;

KompareConnectWidgetFrame::KompareConnectWidgetFrame(ViewSettings* settings,
        KompareSplitter* parent,
        const char* name) :
    QSplitterHandle(Qt::Horizontal, (QSplitter*)parent),
    m_wid(settings, this, name),
    m_label(QStringLiteral(" "), this), // putting a space here because Qt 4 computes different size hints for empty labels
    m_layout(this)
{
    setObjectName(QLatin1String(name));
    setSizePolicy(QSizePolicy(QSizePolicy::Fixed, QSizePolicy::Ignored));
    m_wid.setSizePolicy(QSizePolicy(QSizePolicy::Ignored, QSizePolicy::Ignored));
    m_label.setSizePolicy(QSizePolicy(QSizePolicy::Ignored, QSizePolicy::Fixed));
    m_label.setMargin(3);
    QFrame* bottomLine = new QFrame(this);
    bottomLine->setFrameShape(QFrame::HLine);
    bottomLine->setFrameShadow(QFrame::Plain);
    bottomLine->setSizePolicy(QSizePolicy(QSizePolicy::Ignored, QSizePolicy::Fixed));
    bottomLine->setFixedHeight(1);
    m_layout.setSpacing(0);
    m_layout.setContentsMargins(0, 0, 0, 0);
    m_layout.addWidget(&m_label);
    m_layout.addWidget(bottomLine);
    m_layout.addWidget(&m_wid);
}

KompareConnectWidgetFrame::~KompareConnectWidgetFrame()
{
}

QSize KompareConnectWidgetFrame::sizeHint() const
{
    return QSize(50, style()->pixelMetric(QStyle::PM_ScrollBarExtent));
}

#if 0
static int kMouseOffset;

void KompareConnectWidgetFrame::mouseMoveEvent(QMouseEvent* e)
{

    if (!(e->state()&Qt::LeftButton))
        return;

    QCOORD pos = s->pick(parentWidget()->mapFromGlobal(e->globalPos()))
                 - kMouseOffset;

    ((KompareSplitter*)s)->moveSplitter(pos, id());
}

void KompareConnectWidgetFrame::mousePressEvent(QMouseEvent* e)
{
    if (e->button() == Qt::LeftButton)
        kMouseOffset = s->pick(e->pos());
    QSplitterHandle::mousePressEvent(e);
}

void KompareConnectWidgetFrame::mouseReleaseEvent(QMouseEvent* e)
{
    if (!opaque() && e->button() == Qt::LeftButton) {
        QCOORD pos = s->pick(parentWidget()->mapFromGlobal(e->globalPos()))
                     - kMouseOffset;
        ((KompareSplitter*)s)->moveSplitter(pos, id());
    }
}
#endif

KompareConnectWidget::KompareConnectWidget(ViewSettings* settings, QWidget* parent, const char* name)
    : QWidget(parent),
      m_settings(settings),
      m_selectedModel(nullptr),
      m_selectedDifference(nullptr)
{
    setObjectName(QLatin1String(name));
//     connect( m_settings, SIGNAL( settingsChanged() ), this, SLOT( slotDelayedRepaint() ) );
    setAttribute(Qt::WA_NoSystemBackground, true);
    setSizePolicy(QSizePolicy(QSizePolicy::Fixed, QSizePolicy::Minimum));
    setFocusProxy(parent->parentWidget());
}

KompareConnectWidget::~KompareConnectWidget()
{
    m_settings = nullptr;
    m_selectedModel = nullptr;
    m_selectedDifference = nullptr;
}

void KompareConnectWidget::slotSetSelection(const DiffModel* model, const Difference* diff)
{
    if (m_selectedModel == model && m_selectedDifference == diff)
        return;

    if (m_selectedModel == model && m_selectedDifference != diff)
    {
        m_selectedDifference = diff;
        slotDelayedRepaint();
        return;
    }

    m_selectedModel = model;
    m_selectedDifference = diff;

    slotDelayedRepaint();
}

void KompareConnectWidget::slotDelayedRepaint()
{
    QTimer::singleShot(0, this, static_cast<void(KompareConnectWidget::*)()>(&KompareConnectWidget::repaint));
}

void KompareConnectWidget::slotSetSelection(const Difference* diff)
{
    if (m_selectedDifference == diff)
        return;

    m_selectedDifference = diff;

    slotDelayedRepaint();
}

void KompareConnectWidget::paintEvent(QPaintEvent* /* e */)
{
    QPixmap pixbuf(size());
    QPainter paint(&pixbuf);
    QPainter* p = &paint;

    p->setRenderHint(QPainter::Antialiasing);
    p->fillRect(0, 0, pixbuf.width(), pixbuf.height(), palette().color(QPalette::Window));
    p->translate(QPointF(0, 0.5));

    KompareSplitter* splitter = static_cast<KompareSplitter*>(parent()->parent());
    int count = splitter->count();
    KompareListView* leftView = count >= 2 ? static_cast<KompareListViewFrame*>(splitter->widget(0))->view() : nullptr;
    KompareListView* rightView = count >= 2 ? static_cast<KompareListViewFrame*>(splitter->widget(1))->view() : nullptr;

    if (m_selectedModel && leftView && rightView)
    {
        int firstL = leftView->firstVisibleDifference();
        int firstR = rightView->firstVisibleDifference();
        int lastL = leftView->lastVisibleDifference();
        int lastR = rightView->lastVisibleDifference();

        int first = firstL < 0 ? firstR : qMin(firstL, firstR);
        int last = lastL < 0 ? lastR : qMax(lastL, lastR);
//         qCDebug(KOMPAREPART) << "    left: " << firstL << " - " << lastL ;
//         qCDebug(KOMPAREPART) << "   right: " << firstR << " - " << lastR ;
//         qCDebug(KOMPAREPART) << " drawing: " << first << " - " << last ;
        if (first >= 0 && last >= 0 && first <= last)
        {
            const DifferenceList* differences  = const_cast<DiffModel*>(m_selectedModel)->differences();
            QRect leftRect, rightRect;
            for (int i = first; i <= last; ++i)
            {
                Difference* diff = differences->at(i);
                bool selected = (diff == m_selectedDifference);

                if (QApplication::isRightToLeft())
                {
                    leftRect = rightView->itemRect(i);
                    rightRect = leftView->itemRect(i);
                }
                else
                {
                    leftRect = leftView->itemRect(i);
                    rightRect = rightView->itemRect(i);
                }

                int tl = leftRect.top();
                int tr = rightRect.top();
                int bl = leftRect.bottom();
                int br = rightRect.bottom();

                // Bah, stupid 16-bit signed shorts in that crappy X stuff...
                tl = tl >= -32768 ? tl : -32768;
                tr = tr >= -32768 ? tr : -32768;
                bl = bl <=  32767 ? bl :  32767;
                br = br <=  32767 ? br :  32767;

                QPainterPath topBezier = makeBezier(tl, tr);
                QPainterPath bottomBezier = makeBezier(bl, br);

                QPainterPath poly(topBezier);
                poly.connectPath(bottomBezier.toReversed());
                poly.closeSubpath();

                QColor bg = m_settings->colorForDifferenceType(diff->type(), selected, diff->applied());
                p->setPen(bg);
                p->setBrush(bg);
                p->drawPath(poly);

                if (selected)
                {
                    p->setPen(bg.darker(135));
                    p->setBrush(Qt::NoBrush);
                    p->drawPath(topBezier);
                    p->drawPath(bottomBezier.toReversed());
                }
            }
        }
    }

//     p->flush();
    QPainter widgetPainter(this);
    widgetPainter.drawImage(0, 0, pixbuf.toImage());
}

QPainterPath KompareConnectWidget::makeBezier(int leftHeight, int rightHeight) const
{
    int r = width();
    int o = (int)((double)r * 0.4); // 40% of width

    QPainterPath p(QPointF(0, leftHeight));
    if (leftHeight == rightHeight) {
        p.lineTo(QPointF(r, rightHeight));
    } else {
        p.cubicTo(QPointF(o, leftHeight), QPointF(r - o, rightHeight), QPointF(r, rightHeight));
    }
    return p;
}

#include "moc_kompareconnectwidget.cpp"
