/*
 * Copyright (C) 2020 Emeric Poupon
 *
 * This file is part of LMS.
 *
 * LMS is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * LMS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "JPEGImage.hpp"

#define STB_IMAGE_WRITE_IMPLEMENTATION
#include <stb_image_write.h>

#include "core/ITraceLogger.hpp"
#include "image/Exception.hpp"

#include "RawImage.hpp"

namespace lms::image::STB
{
    JPEGImage::JPEGImage(const RawImage& rawImage, unsigned quality)
    {
        LMS_SCOPED_TRACE_DETAILED("Image", "WriteJPEG");

        auto writeCb{ [](void* ctx, void* writeData, int writeSize) {
            auto& output{ *reinterpret_cast<std::vector<std::byte>*>(ctx) };
            const std::size_t currentOutputSize{ output.size() };
            output.resize(currentOutputSize + writeSize);
            std::copy(reinterpret_cast<const std::byte*>(writeData), reinterpret_cast<const std::byte*>(writeData) + writeSize, output.data() + currentOutputSize);
        } };

        if (stbi_write_jpg_to_func(writeCb, &_data, rawImage.getWidth(), rawImage.getHeight(), 3, rawImage.getData(), quality) == 0)
        {
            _data.clear();
            throw Exception{ "Failed to export in jpeg format!" };
        }
    }

    const std::byte*
    JPEGImage::getData() const
    {
        if (_data.empty())
            return nullptr;

        return &_data.front();
    }

    std::size_t
    JPEGImage::getDataSize() const
    {
        return _data.size();
    }
} // namespace lms::image::STB