/****************************************************************************
**
** Copyright (C) 2016 Robin Burchell <robin.burchell@viroteck.net>
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
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** This file is part of the plugins of the Qt Toolkit.
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** ensure the GNU Lesser General Public License version 3 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
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#include "qwaylandabstractdecoration_p.h"

#include <private/qobject_p.h>
#include "qwaylandwindow_p.h"
#include "qwaylandshellsurface_p.h"
#include "qwaylandinputdevice_p.h"
#include "qwaylandscreen_p.h"

#include <QtGui/QImage>

QT_BEGIN_NAMESPACE

namespace QtWaylandClient {

class QWaylandAbstractDecorationPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QWaylandAbstractDecoration)

public:
    QWaylandAbstractDecorationPrivate();
    ~QWaylandAbstractDecorationPrivate() override;

    QWindow *m_window = nullptr;
    QWaylandWindow *m_wayland_window = nullptr;

    bool m_isDirty = true;
    QImage m_decorationContentImage;

    Qt::MouseButtons m_mouseButtons = Qt::NoButton;
};

QWaylandAbstractDecorationPrivate::QWaylandAbstractDecorationPrivate()
    : m_decorationContentImage(nullptr)
{
}

QWaylandAbstractDecorationPrivate::~QWaylandAbstractDecorationPrivate()
{
}

QWaylandAbstractDecoration::QWaylandAbstractDecoration()
    : QObject(*new QWaylandAbstractDecorationPrivate)
{
}

QWaylandAbstractDecoration::~QWaylandAbstractDecoration()
{
}

// we do this as a setter to get around plugin factory creates not really
// being a great way to pass arguments
void QWaylandAbstractDecoration::setWaylandWindow(QWaylandWindow *window)
{
    Q_D(QWaylandAbstractDecoration);

    // double initialization is probably not great
    Q_ASSERT(!d->m_window && !d->m_wayland_window);

    d->m_window = window->window();
    d->m_wayland_window = window;
}

// Creates regions like this on the outside of a rectangle with inner size \a size
// -----
// |   |
// -----
// I.e. the top and bottom extends into the corners
static QRegion marginsRegion(const QSize &size, const QMargins &margins)
{
    QRegion r;
    const int widthWithMargins = margins.left() + size.width() + margins.right();
    r += QRect(0, 0, widthWithMargins, margins.top()); // top
    r += QRect(0, size.height()+margins.top(), widthWithMargins, margins.bottom()); //bottom
    r += QRect(0, margins.top(), margins.left(), size.height()); //left
    r += QRect(size.width()+margins.left(), margins.top(), margins.right(), size.height()); // right
    return r;
}

const QImage &QWaylandAbstractDecoration::contentImage()
{
    Q_D(QWaylandAbstractDecoration);
    if (d->m_isDirty) {
        // Update the decoration backingstore

        const int bufferScale = waylandWindow()->scale();
        const QSize imageSize = waylandWindow()->surfaceSize() * bufferScale;
        d->m_decorationContentImage = QImage(imageSize, QImage::Format_ARGB32_Premultiplied);
        // Only scale by buffer scale, not QT_SCALE_FACTOR etc.
        d->m_decorationContentImage.setDevicePixelRatio(bufferScale);
        d->m_decorationContentImage.fill(Qt::transparent);
        this->paint(&d->m_decorationContentImage);

        QRegion damage = marginsRegion(waylandWindow()->surfaceSize(), waylandWindow()->frameMargins());
        for (QRect r : damage)
            waylandWindow()->damage(r);

        d->m_isDirty = false;
    }

    return d->m_decorationContentImage;
}

void QWaylandAbstractDecoration::update()
{
    Q_D(QWaylandAbstractDecoration);
    d->m_isDirty = true;
}

void QWaylandAbstractDecoration::setMouseButtons(Qt::MouseButtons mb)
{
    Q_D(QWaylandAbstractDecoration);
    d->m_mouseButtons = mb;
}

void QWaylandAbstractDecoration::startResize(QWaylandInputDevice *inputDevice, Qt::Edges edges, Qt::MouseButtons buttons)
{
    Q_D(QWaylandAbstractDecoration);
    if (isLeftClicked(buttons) && d->m_wayland_window->shellSurface()) {
        d->m_wayland_window->shellSurface()->resize(inputDevice, edges);
        inputDevice->removeMouseButtonFromState(Qt::LeftButton);
    }
}

void QWaylandAbstractDecoration::startMove(QWaylandInputDevice *inputDevice, Qt::MouseButtons buttons)
{
    Q_D(QWaylandAbstractDecoration);
    if (isLeftClicked(buttons) && d->m_wayland_window->shellSurface()) {
        d->m_wayland_window->shellSurface()->move(inputDevice);
        inputDevice->removeMouseButtonFromState(Qt::LeftButton);
    }
}

void QWaylandAbstractDecoration::showWindowMenu(QWaylandInputDevice *inputDevice)
{
    Q_D(QWaylandAbstractDecoration);
    if (auto *s = d->m_wayland_window->shellSurface())
        s->showWindowMenu(inputDevice);
}

bool QWaylandAbstractDecoration::isLeftClicked(Qt::MouseButtons newMouseButtonState)
{
    Q_D(QWaylandAbstractDecoration);
    return !(d->m_mouseButtons & Qt::LeftButton) && (newMouseButtonState & Qt::LeftButton);
}

bool QWaylandAbstractDecoration::isRightClicked(Qt::MouseButtons newMouseButtonState)
{
    Q_D(QWaylandAbstractDecoration);
    return !(d->m_mouseButtons & Qt::RightButton) && (newMouseButtonState & Qt::RightButton);
}

bool QWaylandAbstractDecoration::isLeftReleased(Qt::MouseButtons newMouseButtonState)
{
    Q_D(QWaylandAbstractDecoration);
    return (d->m_mouseButtons & Qt::LeftButton) && !(newMouseButtonState & Qt::LeftButton);
}

bool QWaylandAbstractDecoration::isDirty() const
{
    Q_D(const QWaylandAbstractDecoration);
    return d->m_isDirty;
}

QWindow *QWaylandAbstractDecoration::window() const
{
    Q_D(const QWaylandAbstractDecoration);
    return d->m_window;
}

QWaylandWindow *QWaylandAbstractDecoration::waylandWindow() const
{
    Q_D(const QWaylandAbstractDecoration);
    return d->m_wayland_window;
}

}

QT_END_NAMESPACE