/*
    SPDX-FileCopyrightText: 2023 Xaver Hugl <xaver.hugl@gmail.com>

    SPDX-License-Identifier: GPL-2.0-or-later
*/
#pragma once

#include "core/colorpipeline.h"
#include "core/colorspace.h"
#include "kwin_export.h"

#include <QMatrix4x4>
#include <QString>
#include <expected>
#include <memory>
#include <optional>

typedef void *cmsHPROFILE;

namespace KWin
{

class ColorTransformation;
class ColorLUT3D;

class KWIN_EXPORT IccProfile
{
public:
    explicit IccProfile(cmsHPROFILE handle, const Colorimetry &colorimetry, std::optional<ColorPipeline> &&bToA0Tag, std::optional<ColorPipeline> &&bToA1Tag, const std::shared_ptr<ColorTransformation> &inverseEOTF, const QMatrix4x4 &xyzMatrix, const std::shared_ptr<ColorTransformation> &vcgt, std::optional<double> relativeBlackPoint, std::optional<double> maxFALL, std::optional<double> maxCLL);
    ~IccProfile();

    /**
     * the BToA tag describes a transformation from XYZ with D50 whitepoint
     * to the display color space. May be nullptr!
     */
    const ColorPipeline *BToATag(RenderingIntent intent) const;
    /**
     * NOTE that this inverse transfer function is an estimation
     * and not necessarily exact!
     */
    std::shared_ptr<ColorTransformation> inverseTransferFunction() const;
    /**
     * The VCGT is a non-standard tag that needs to be applied before
     * pixels are sent to the display. May be nullptr!
     * If the profile has a MHC2 tag, this returns the 1D LUT from that tag
     * rather than the actual VCGT tag.
     */
    std::shared_ptr<ColorTransformation> vcgt() const;
    /**
     * This comes from the non-standard 'MHC2' tag Microsoft uses.
     * It needs to be applied in XYZ space before scanout
     */
    const QMatrix4x4 &mhc2Matrix() const;
    const Colorimetry &colorimetry() const;
    /**
     * relative to maxFALL, not maxCLL
     */
    std::optional<double> relativeBlackPoint() const;
    std::optional<double> maxFALL() const;
    std::optional<double> maxCLL() const;

    /**
     * If the non-standard 'MHC2' tag is used, the behavior of
     * the profile changes in three ways:
     * - the mhc2 matrix must be applied in XYZ space. It can be
     *   assumed to be scale-invariant
     * - the wire colorimetry must be used to convert back to RGB
     *   (instead of the native gamut encoded in this profile)
     * - the wire transfer function must be used instead of the
     *   TRC encoded in this profile (which is often nonsense)
     */
    bool hasMHC2Tag() const;

    static std::expected<std::unique_ptr<IccProfile>, QString> load(const QString &path);
    static const ColorDescription s_connectionSpace;

private:
    cmsHPROFILE const m_handle;
    const Colorimetry m_colorimetry;
    const std::optional<ColorPipeline> m_bToA0Tag;
    const std::optional<ColorPipeline> m_bToA1Tag;
    const std::shared_ptr<ColorTransformation> m_inverseEOTF;
    const QMatrix4x4 m_xyzMatrix;
    const std::shared_ptr<ColorTransformation> m_vcgt;
    const std::optional<double> m_relativeBlackPoint;
    const std::optional<double> m_maxFALL;
    const std::optional<double> m_maxCLL;
    const bool m_hasMHC2;
};

}