// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#ifndef QSHADERDESCRIPTION_H
#define QSHADERDESCRIPTION_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists for the convenience
// of a number of Qt sources files.  This header file may change from
// version to version without notice, or even be removed.
//
// We mean it.
//

#include <QtGui/qtguiglobal.h>
#include <QtCore/QString>
#include <QtCore/QList>
#include <QtCore/private/qglobal_p.h>
#include <array>

QT_BEGIN_NAMESPACE

struct QShaderDescriptionPrivate;
class QDataStream;

class Q_GUI_EXPORT QShaderDescription
{
public:
    QShaderDescription();
    QShaderDescription(const QShaderDescription &other);
    QShaderDescription &operator=(const QShaderDescription &other);
    ~QShaderDescription();
    void detach();

    bool isValid() const;

    void serialize(QDataStream *stream) const;
    QByteArray toJson() const;

    static QShaderDescription deserialize(QDataStream *stream, int version);

    enum VariableType {
        Unknown = 0,

        // do not reorder
        Float,
        Vec2,
        Vec3,
        Vec4,
        Mat2,
        Mat2x3,
        Mat2x4,
        Mat3,
        Mat3x2,
        Mat3x4,
        Mat4,
        Mat4x2,
        Mat4x3,

        Int,
        Int2,
        Int3,
        Int4,

        Uint,
        Uint2,
        Uint3,
        Uint4,

        Bool,
        Bool2,
        Bool3,
        Bool4,

        Double,
        Double2,
        Double3,
        Double4,
        DMat2,
        DMat2x3,
        DMat2x4,
        DMat3,
        DMat3x2,
        DMat3x4,
        DMat4,
        DMat4x2,
        DMat4x3,

        Sampler1D,
        Sampler2D,
        Sampler2DMS,
        Sampler3D,
        SamplerCube,
        Sampler1DArray,
        Sampler2DArray,
        Sampler2DMSArray,
        Sampler3DArray,
        SamplerCubeArray,
        SamplerRect,
        SamplerBuffer,
        SamplerExternalOES,
        Sampler,

        Image1D,
        Image2D,
        Image2DMS,
        Image3D,
        ImageCube,
        Image1DArray,
        Image2DArray,
        Image2DMSArray,
        Image3DArray,
        ImageCubeArray,
        ImageRect,
        ImageBuffer,

        Struct
    };

    enum ImageFormat {
        // must match SPIR-V's ImageFormat
        ImageFormatUnknown = 0,
        ImageFormatRgba32f = 1,
        ImageFormatRgba16f = 2,
        ImageFormatR32f = 3,
        ImageFormatRgba8 = 4,
        ImageFormatRgba8Snorm = 5,
        ImageFormatRg32f = 6,
        ImageFormatRg16f = 7,
        ImageFormatR11fG11fB10f = 8,
        ImageFormatR16f = 9,
        ImageFormatRgba16 = 10,
        ImageFormatRgb10A2 = 11,
        ImageFormatRg16 = 12,
        ImageFormatRg8 = 13,
        ImageFormatR16 = 14,
        ImageFormatR8 = 15,
        ImageFormatRgba16Snorm = 16,
        ImageFormatRg16Snorm = 17,
        ImageFormatRg8Snorm = 18,
        ImageFormatR16Snorm = 19,
        ImageFormatR8Snorm = 20,
        ImageFormatRgba32i = 21,
        ImageFormatRgba16i = 22,
        ImageFormatRgba8i = 23,
        ImageFormatR32i = 24,
        ImageFormatRg32i = 25,
        ImageFormatRg16i = 26,
        ImageFormatRg8i = 27,
        ImageFormatR16i = 28,
        ImageFormatR8i = 29,
        ImageFormatRgba32ui = 30,
        ImageFormatRgba16ui = 31,
        ImageFormatRgba8ui = 32,
        ImageFormatR32ui = 33,
        ImageFormatRgb10a2ui = 34,
        ImageFormatRg32ui = 35,
        ImageFormatRg16ui = 36,
        ImageFormatRg8ui = 37,
        ImageFormatR16ui = 38,
        ImageFormatR8ui = 39
    };

    enum ImageFlag {
        ReadOnlyImage = 1 << 0,
        WriteOnlyImage = 1 << 1
    };
    Q_DECLARE_FLAGS(ImageFlags, ImageFlag)

    // Optional data (like decorations) usually default to an otherwise invalid value (-1 or 0). This is intentional.

    struct InOutVariable {
        QByteArray name;
        VariableType type = Unknown;
        int location = -1;
        int binding = -1;
        int descriptorSet = -1;
        ImageFormat imageFormat = ImageFormatUnknown;
        ImageFlags imageFlags;
        QList<int> arrayDims;
    };

    struct BlockVariable {
        QByteArray name;
        VariableType type = Unknown;
        int offset = 0;
        int size = 0;
        QList<int> arrayDims;
        int arrayStride = 0;
        int matrixStride = 0;
        bool matrixIsRowMajor = false;
        QList<BlockVariable> structMembers;
    };

    struct UniformBlock {
        QByteArray blockName;
        QByteArray structName; // instanceName
        int size = 0;
        int binding = -1;
        int descriptorSet = -1;
        QList<BlockVariable> members;
    };

    struct PushConstantBlock {
        QByteArray name;
        int size = 0;
        QList<BlockVariable> members;
    };

    struct StorageBlock {
        QByteArray blockName;
        QByteArray instanceName;
        int knownSize = 0;
        int binding = -1;
        int descriptorSet = -1;
        QList<BlockVariable> members;
    };

    QList<InOutVariable> inputVariables() const;
    QList<InOutVariable> outputVariables() const;
    QList<UniformBlock> uniformBlocks() const;
    QList<PushConstantBlock> pushConstantBlocks() const;
    QList<StorageBlock> storageBlocks() const;
    QList<InOutVariable> combinedImageSamplers() const;
    QList<InOutVariable> separateImages() const;
    QList<InOutVariable> separateSamplers() const;
    QList<InOutVariable> storageImages() const;

    std::array<uint, 3> computeShaderLocalSize() const;

private:
    QShaderDescriptionPrivate *d;
    friend struct QShaderDescriptionPrivate;
#ifndef QT_NO_DEBUG_STREAM
    friend Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription &);
#endif
    friend Q_GUI_EXPORT bool operator==(const QShaderDescription &lhs, const QShaderDescription &rhs) noexcept;
};

Q_DECLARE_OPERATORS_FOR_FLAGS(QShaderDescription::ImageFlags)

#ifndef QT_NO_DEBUG_STREAM
Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription &);
Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription::InOutVariable &);
Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription::BlockVariable &);
Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription::UniformBlock &);
Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription::PushConstantBlock &);
Q_GUI_EXPORT QDebug operator<<(QDebug, const QShaderDescription::StorageBlock &);
#endif

Q_GUI_EXPORT bool operator==(const QShaderDescription &lhs, const QShaderDescription &rhs) noexcept;
Q_GUI_EXPORT bool operator==(const QShaderDescription::InOutVariable &lhs, const QShaderDescription::InOutVariable &rhs) noexcept;
Q_GUI_EXPORT bool operator==(const QShaderDescription::BlockVariable &lhs, const QShaderDescription::BlockVariable &rhs) noexcept;
Q_GUI_EXPORT bool operator==(const QShaderDescription::UniformBlock &lhs, const QShaderDescription::UniformBlock &rhs) noexcept;
Q_GUI_EXPORT bool operator==(const QShaderDescription::PushConstantBlock &lhs, const QShaderDescription::PushConstantBlock &rhs) noexcept;
Q_GUI_EXPORT bool operator==(const QShaderDescription::StorageBlock &lhs, const QShaderDescription::StorageBlock &rhs) noexcept;

inline bool operator!=(const QShaderDescription &lhs, const QShaderDescription &rhs) noexcept
{
    return !(lhs == rhs);
}

inline bool operator!=(const QShaderDescription::InOutVariable &lhs, const QShaderDescription::InOutVariable &rhs) noexcept
{
    return !(lhs == rhs);
}

inline bool operator!=(const QShaderDescription::BlockVariable &lhs, const QShaderDescription::BlockVariable &rhs) noexcept
{
    return !(lhs == rhs);
}

inline bool operator!=(const QShaderDescription::UniformBlock &lhs, const QShaderDescription::UniformBlock &rhs) noexcept
{
    return !(lhs == rhs);
}

inline bool operator!=(const QShaderDescription::PushConstantBlock &lhs, const QShaderDescription::PushConstantBlock &rhs) noexcept
{
    return !(lhs == rhs);
}

inline bool operator!=(const QShaderDescription::StorageBlock &lhs, const QShaderDescription::StorageBlock &rhs) noexcept
{
    return !(lhs == rhs);
}

QT_END_NAMESPACE

#endif