/*
    SPDX-FileCopyrightText: 2014 Martin Gräßlin <mgraesslin@kde.org>

    SPDX-License-Identifier: LGPL-2.1-only OR LGPL-3.0-only OR LicenseRef-KDE-Accepted-LGPL
*/
#ifndef WAYLAND_SURFACE_H
#define WAYLAND_SURFACE_H

#include "buffer.h"

#include <QObject>
#include <QPoint>
#include <QSize>
#include <QWindow>

#include "KWayland/Client/kwaylandclient_export.h"

struct wl_buffer;
struct wl_surface;

class QWindow;

namespace KWayland
{
namespace Client
{
class Output;
class Region;

/**
 * @short Wrapper for the wl_surface interface.
 *
 * This class is a convenient wrapper for the wl_surface interface.
 * To create a Surface call Compositor::createSurface.
 *
 * The main purpose of this class is to setup the next frame which
 * should be rendered. Therefore it provides methods to add damage
 * and to attach a new Buffer and to finalize the frame by calling
 * commit.
 *
 * @see Compositor
 **/
class KWAYLANDCLIENT_EXPORT Surface : public QObject
{
    Q_OBJECT
public:
    explicit Surface(QObject *parent = nullptr);
    ~Surface() override;

    /**
     * Creates a Surface for the given @p window.
     * This is an integration feature for QtWayland. On non-wayland platforms this method returns
     * @c nullptr as well as for not created QWindows.
     *
     * The returned Surface will be fully setup, but won't be released. It gets automatically
     * destroyed together with the @p window or when the internal wl_surface get destroyed.
     * QtWayland may destroy wl_surface when hiding the window, you should always call
     * this function instead of holding the returned pointer.
     * @since 5.4
     **/
    static Surface *fromWindow(QWindow *window);

    /**
     * Creates a Surface for the given @p winId.
     * This is an integration feature for QtWayland. On non-wayland platforms this method returns
     * @c nullptr as well as for not created QWindows.
     *
     * The returned Surface will be fully setup, but won't be released. It gets automatically
     * destroyed together with the QWindow or the wl_surface corresponding.
     * the @p wid.
     * @since 5.5
     * @see fromWindow
     **/
    static Surface *fromQtWinId(WId wid);

    /**
     * Setup this Surface to manage the @p surface.
     * When using Compositor::createSurface there is no need to call this
     * method.
     **/
    void setup(wl_surface *surface);
    /**
     * Releases the wl_surface interface.
     * After the interface has been released the Surface instance is no
     * longer valid and can be setup with another wl_surface interface.
     **/
    void release();
    /**
     * Destroys the data held by this Surface.
     * This method is supposed to be used when the connection to the Wayland
     * server goes away. If the connection is not valid anymore, it's not
     * possible to call release anymore as that calls into the Wayland
     * connection and the call would fail. This method cleans up the data, so
     * that the instance can be deleted or set up to a new wl_surface interface
     * once there is a new connection available.
     *
     * This method is automatically invoked when the Registry which created this
     * Surface gets destroyed.
     *
     * @see release
     **/
    void destroy();
    /**
     * @returns @c true if managing a wl_surface.
     **/
    bool isValid() const;
    /**
     * Registers a frame rendered callback.
     * This registers a callback in the Wayland server to be notified once the
     * next frame for this Surface has been rendered. The Surface will emit the
     * signal frameRendered after receiving the callback from the server.
     *
     * Instead of using this method one should prefer using the CommitFlag::FrameCallback
     * in commit. This method is intended for cases when the Surface is going to
     * be committed on other ways, e.g. through the OpenGL/EGL stack.
     *
     * @see frameRendered
     * @see commit
     **/
    void setupFrameCallback();
    /**
     * Flags to be added to commit.
     * @li None: no flag
     * @li FrameCallback: register a frame rendered callback
     *
     * Instead of setting the FrameCallback flag one can also call
     * setupFrameCallback. If one uses setupFrameCallback one may not
     * use the FrameCallback flag when committing the Surface.
     *
     * @see commit
     * @see setupFrameCallback
     **/
    enum class CommitFlag {
        None,
        FrameCallback,
    };
    void commit(CommitFlag flag = CommitFlag::FrameCallback);
    /**
     * Mark @p rect as damaged for the next frame.
     * @see damageBuffer
     **/
    void damage(const QRect &rect);
    /**
     * Mark @p region as damaged for the next frame.
     * @see damageBuffer
     **/
    void damage(const QRegion &region);
    /**
     * Mark @p rect in buffer coordinates as damaged for the next frame.
     * @see damage
     * @since 5.59
     **/
    void damageBuffer(const QRect &rect);
    /**
     * Mark @p region in buffer coordinates as damaged for the next frame.
     * @see damage
     * @since 5.59
     **/
    void damageBuffer(const QRegion &region);
    /**
     * Attaches the @p buffer to this Surface for the next frame.
     * @param buffer The buffer to attach to this Surface
     * @param offset Position of the new upper-left corner in relation to previous frame
     **/
    void attachBuffer(wl_buffer *buffer, const QPoint &offset = QPoint());
    /**
     * Overloaded method for convenience.
     **/
    void attachBuffer(Buffer *buffer, const QPoint &offset = QPoint());
    /**
     * Overloaded method for convenience.
     **/
    void attachBuffer(Buffer::Ptr buffer, const QPoint &offset = QPoint());
    /**
     * Sets the input region to @p region.
     *
     * This is a double buffered state and will be applied with the next Surface
     * commit. Initially the Surface is set up to an infinite input region.
     * By passing @c null as the input region, it gets reset to an infinite input
     * region.
     *
     * Note: the Region is being copied and can be destroyed directly after passing
     * to this method.
     *
     * @param region The new input region or an infinite region if @c null
     * @see commit
     **/
    void setInputRegion(const Region *region = nullptr);
    /**
     * Sets the opaque region to @p region.
     *
     * This is a double buffered state and will be applied with the next Surface
     * commit. Initially the Surface is set up to an empty opaque region.
     * By passing @c null as the opaque region, it gets reset to an empty opaque
     * region.
     *
     * Note: the Region is being copied and can be destroyed directly after passing
     * to this method.
     *
     * @param region The new opaque region or an empty region if @c null
     * @see commit
     **/
    void setOpaqueRegion(const Region *region = nullptr);
    void setSize(const QSize &size);
    QSize size() const;

    /**
     * The purpose of this method is to allow to supply higher resolution buffer data for use
     * on high resolution outputs. It's intended that the same buffer scale as the scale of the
     * output that the surface is displayed on is used.
     * This means the compositor can avoid scaling when rendering the surface on that output.
     *
     * Note that if @p scale is larger than 1 you have to attach a buffer that is larger
     * (by a factor of scale in each dimension) than the desired surface size.
     *
     * The default scale factor is 1.
     *
     * The state is only applied with the next commit.
     *
     * @see scale
     * @see commit
     * @since 5.22
     **/
    void setScale(qint32 scale);
    /**
     * @returns The current scale factor, if not explicitly set it's @c 1.
     * @see setScale
     * @since 5.22
     **/
    qint32 scale() const;

    operator wl_surface *();
    operator wl_surface *() const;

    /**
     * @returns the id of the referenced wl_proxy.
     * @since 5.4
     **/
    quint32 id() const;

    /**
     * @returns All Outputs the Surface is on, may be none.
     * @see outputEntered
     * @see outputLeft
     * @since 5.27
     **/
    QVector<Output *> outputs() const;

    /**
     * All Surfaces which are currently created.
     * TODO: KF6 return QList<Surface*> instead of const-ref
     **/
    static const QList<Surface *> &all(); // krazy:exclude=constref
    /**
     * @returns The Surface referencing the @p native wl_surface or @c null if there is no such Surface.
     **/
    static Surface *get(wl_surface *native);

Q_SIGNALS:
    /**
     * Emitted when the server indicates that the last committed frame has been rendered.
     * The signal will only be emitted if a callback has been registered by either calling
     * setupFrameCallback or calling commit with the CommitFlag::FrameCallback.
     * @see setupFrameCallback
     * @see commit
     **/
    void frameRendered();
    void sizeChanged(const QSize &);

    /**
     * Emitted whenever a change in the Surface (e.g. creation, movement, resize) results in
     * a part of the Surface being within the scanout region of the Output @p o.
     *
     * @param o The Output the Surface intersects with
     * @see outputLeft
     * @see outputs
     * @since 5.27
     **/
    void outputEntered(KWayland::Client::Output *o);

    /**
     * Emitted whenever a change in the Surface (e.g. creation, movement, resize, unmapping)
     * results in the Surface no longer being within the scanout region of the Output @p o.
     *
     * @param o The Output the Surface no longer intersects with
     * @see outputEntered
     * @see outputs
     * @since 5.27
     **/
    void outputLeft(KWayland::Client::Output *o);

private:
    class Private;
    QScopedPointer<Private> d;
};

}
}

#endif
