/******************************************************************************
**
** Copyright (C) 2021 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Quick Ultralite module.
**
** $QT_BEGIN_LICENSE:COMM$
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
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** $QT_END_LICENSE$
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******************************************************************************/
#include "desaturation.h"

#include <qul/image.h>
#include <platform/platform.h>
#include <qul/private/texture.h>
#include <qul/private/rasterbuffer.h>

#include <platforminterface/log.h>

#include <cstring>
#include <memory>

#ifdef QUL_TVIIC_PLATFORM
#include <sm_util.h>
#include <pe_matrix.h>
#include "cygfx.h"
#else
#include <QImage>
#include <QPainter>
#include <QVector>
#include "desktop.h"
#endif

#include <qul/private/unicodestring.h>
#include <qul/private/image_p.h>

Qul::PlatformInterface::Rect DesaturationDelegate::boundingRect(Qul::PlatformInterface::Size) const
{
    if (source.value().textureCount() != 1) {
        Qul::PlatformInterface::log("TVII effects: desaturation: Unexpected texture count %i\r\n",
                                    source.value().textureCount());
        std::terminate();
    }

    auto texture = source.value().texture();
    return Qul::PlatformInterface::Rect(0, 0, texture.width(), texture.height());
}

#ifndef QUL_TVIIC_PLATFORM
QImage desaturated(const QImage &source, float saturation)
{
    QImage result = source.convertToFormat(QImage::Format_ARGB32_Premultiplied);
    uint32_t *bits = reinterpret_cast<uint32_t *>(result.bits());
    for (int y = 0; y < result.height(); ++y) {
        for (int x = 0; x < result.width(); ++x) {
            uint32_t pixel = bits[x];
            uint32_t gray = qGray(pixel);

            int red = qRed(pixel) * saturation + gray * (1 - saturation);
            int green = qGreen(pixel) * saturation + gray * (1 - saturation);
            int blue = qBlue(pixel) * saturation + gray * (1 - saturation);
            int alpha = qAlpha(pixel);

            bits[x] = qRgba(red, green, blue, alpha);
        }
        bits += result.bytesPerLine() / 4;
    }
    return result;
}
#endif

void DesaturationDelegate::saturationChanged()
{
    update();
}

void DesaturationDelegate::paint(Qul::PlatformInterface::DrawingDevice *device,
                                 const Qul::PlatformInterface::Rect &clip,
                                 const Qul::PlatformInterface::Transform &transform,
                                 Qul::PlatformInterface::Size,
                                 float opacity) const
{
    float saturationValue = saturation.value();

    auto texture = source.value().texture();
    if (!m_initialized) {
#ifdef QUL_TVIIC_PLATFORM
        CyGfx::loadSurface(&m_source, texture);
#endif
        m_initialized = true;
    }

#ifdef QUL_TVIIC_PLATFORM
    void **platformContext = static_cast<void **>(device->platformContext());
    CYGFX_BE_CONTEXT ctx = static_cast<CYGFX_BE_CONTEXT>(platformContext[0]);

    CYGFX_ERROR ret = CYGFX_OK;

    Mat3x3 matrix{transform.m11(),
                  transform.m12(),
                  transform.m13(),
                  transform.m21(),
                  transform.m22(),
                  transform.m23(),
                  transform.dx(),
                  transform.dy(),
                  transform.m33()};

    bool hasClipping = false;
    if (clip != Qul::PlatformInterface::Rect(0, 0, device->width(), device->height())) {
        // Blend only in clip area
        UTIL_SUCCESS(ret,
                     CyGfx_BeSetSurfAttribute(ctx, CYGFX_BE_TARGET_STORE, CYGFX_BE_SURF_ATTR_USE_CLIPPING, CYGFX_TRUE));
        UTIL_SUCCESS(ret,
                     CyGfx_BeActiveArea(ctx, CYGFX_BE_TARGET_STORE, clip.x(), clip.y(), clip.width(), clip.height()));
    }

    UTIL_SUCCESS(ret, CyGfx_BeBindSurface(ctx, CYGFX_BE_TARGET_SRC, m_source));
    if (opacity != 1) {
        UTIL_SUCCESS(ret,
                     CyGfx_BeSetSurfAttribute(ctx,
                                              CYGFX_BE_TARGET_SRC,
                                              CYGFX_BE_SURF_ATTR_COLOR,
                                              CYGFX_SM_COLOR_TO_RGBA(255, 255, 255, int(255 * opacity))));
        UTIL_SUCCESS(ret, CyGfx_BeSetSurfAttribute(ctx, CYGFX_BE_TARGET_SRC, CYGFX_BE_SURF_ATTR_ALPHAMULTI, CYGFX_TRUE));
    }

    Mat4x3 colorMatrix;
    utMat4x3CalcColMatrix(colorMatrix, 1.0f, 0.0f, saturationValue, 0.0f);
    UTIL_SUCCESS(ret, CyGfx_CmSetColorMatrix(ctx, CYGFX_CM_CMATRIX_FORMAT_4X3, colorMatrix));
    UTIL_SUCCESS(ret, CyGfx_BeSetGeoMatrix(ctx, CYGFX_BE_TARGET_SRC, CYGFX_BE_GEO_MATRIX_FORMAT_3X3, matrix));
    UTIL_SUCCESS(ret, CyGfx_BeBlt(ctx, 0, 0));
    UTIL_SUCCESS(ret, CyGfx_CmSetColorMatrix(ctx, CYGFX_CM_CMATRIX_FORMAT_4X3, nullptr));
    UTIL_SUCCESS(ret, CyGfx_BeBindSurface(ctx, CYGFX_BE_TARGET_MASK, nullptr));

    if (hasClipping)
        UTIL_SUCCESS(ret,
                     CyGfx_BeSetSurfAttribute(ctx, CYGFX_BE_TARGET_STORE, CYGFX_BE_SURF_ATTR_USE_CLIPPING, CYGFX_FALSE));
#else
    QPainter *p = static_cast<QPainter *>(device->platformContext());

    QImage image(texture.data(),
                 texture.width(),
                 texture.height(),
                 texture.bytesPerLine(),
                 toQImageFormat(texture.format()));
    QImage desaturatedImage = desaturated(image, saturationValue);

    p->save();
    p->setClipRect(QRect(clip.x(), clip.y(), clip.width(), clip.height()));
    p->setRenderHints(QPainter::Antialiasing | QPainter::SmoothPixmapTransform);
    p->setTransform(toQTransform(transform));
    p->setOpacity(opacity);
    p->drawImage(QPoint(), desaturatedImage);
    p->restore();
#endif
}