/*
    SPDX-FileCopyrightText: 2015 Martin Gräßlin <mgraesslin@kde.org>
    SPDX-FileCopyrightText: 2015 Marco Martin <mart@kde.org>

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

#include <optional>

#include <QObject>
#include <QPoint>
#include <QSize>
#include <QColor>

#include "KWayland/Client/kwaylandclient_export.h"

struct org_kde_kwin_contrast;
struct org_kde_kwin_contrast_manager;

namespace KWayland
{
namespace Client
{
class EventQueue;
class Contrast;
class Surface;
class Region;

/**
 * TODO
 */
class KWAYLANDCLIENT_EXPORT ContrastManager : public QObject
{
    Q_OBJECT
public:
    /**
     * Creates a new ContrastManager.
     * Note: after constructing the ContrastManager it is not yet valid and one needs
     * to call setup. In order to get a ready to use ContrastManager prefer using
     * Registry::createContrastManager.
     **/
    explicit ContrastManager(QObject *parent = nullptr);
    ~ContrastManager() override;

    /**
     * @returns @c true if managing a org_kde_kwin_contrast_manager.
     **/
    bool isValid() const;
    /**
     * Setup this ContrastManager to manage the @p contrastManager.
     * When using Registry::createContrastManager there is no need to call this
     * method.
     **/
    void setup(org_kde_kwin_contrast_manager *contrastManager);
    /**
     * Releases the org_kde_kwin_contrast_manager interface.
     * After the interface has been released the ContrastManager instance is no
     * longer valid and can be setup with another org_kde_kwin_contrast_manager interface.
     **/
    void release();
    /**
     * Destroys the data held by this ContrastManager.
     * 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 org_kde_kwin_contrast_manager interface
     * once there is a new connection available.
     *
     * It is suggested to connect this method to ConnectionThread::connectionDied:
     * @code
     * connect(connection, &ConnectionThread::connectionDied, contrastManager, &ContrastManager::destroy);
     * @endcode
     *
     * @see release
     **/
    void destroy();

    /**
     * Sets the @p queue to use for creating a Contrast.
     **/
    void setEventQueue(EventQueue *queue);
    /**
     * @returns The event queue to use for creating a Contrast.
     **/
    EventQueue *eventQueue();

    /**
     * Creates and setup a new Contrast with @p parent.
     * @param parent The parent to pass to the Contrast.
     * @returns The new created Contrast
     **/
    Contrast *createContrast(Surface *surface, QObject *parent = nullptr);
    void removeContrast(Surface *surface);

    operator org_kde_kwin_contrast_manager *();
    operator org_kde_kwin_contrast_manager *() const;

Q_SIGNALS:
    /**
     * The corresponding global for this interface on the Registry got removed.
     *
     * This signal gets only emitted if the ContrastManager got created by
     * Registry::createContrastManager
     *
     * @since 5.5
     **/
    void removed();

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

/**
 * @short Wrapper for the org_kde_kwin_contrast interface.
 *
 * This class is a convenient wrapper for the org_kde_kwin_contrast interface.
 * To create a Contrast call ContrastManager::createContrast.
 *
 * 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 ContrastManager
 **/
class KWAYLANDCLIENT_EXPORT Contrast : public QObject
{
    Q_OBJECT
public:
    ~Contrast() override;

    /**
     * Setup this Contrast to manage the @p contrast.
     * When using ContrastManager::createContrast there is no need to call this
     * method.
     **/
    void setup(org_kde_kwin_contrast *contrast);
    /**
     * Releases the org_kde_kwin_contrast interface.
     * After the interface has been released the Contrast instance is no
     * longer valid and can be setup with another org_kde_kwin_contrast interface.
     **/
    void release();
    /**
     * Destroys the data held by this Contrast.
     * 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 org_kde_kwin_contrast interface
     * once there is a new connection available.
     *
     * This method is automatically invoked when the Registry which created this
     * Contrast gets destroyed.
     *
     * @see release
     **/
    void destroy();
    /**
     * @returns @c true if managing a org_kde_kwin_contrast.
     **/
    bool isValid() const;

    void commit();

    /**
     * Sets the area of the window that will have a contrasted
     * background.
     * The region will have to be created with
     * Compositor::createRegion(QRegion)
     */
    void setRegion(Region *region);
    void setContrast(qreal contrast);
    void setIntensity(qreal intensity);
    void setSaturation(qreal saturation);

    void setFrost(QColor frost);

    operator org_kde_kwin_contrast *();
    operator org_kde_kwin_contrast *() const;

private:
    friend class ContrastManager;
    explicit Contrast(QObject *parent = nullptr);
    class Private;
    QScopedPointer<Private> d;
};

}
}

#endif