#include "Pixel_Frame.h"
#include <cstring>
#include <limits>
namespace renderive::web {
namespace {
void write_u32_le(char* target, std::uint32_t value) {
    target[0] = static_cast<char>(value & 0xffU);
    target[1] = static_cast<char>((value >> 8U) & 0xffU);
    target[2] = static_cast<char>((value >> 16U) & 0xffU);
    target[3] = static_cast<char>((value >> 24U) & 0xffU);
}
}
std::string encode_rgba8_pixel_frame(const std::byte* data, std::uint32_t width, std::uint32_t height, std::uint32_t stride) {
    if (data == nullptr || width == 0 || height == 0 || stride < width * 4U)
        return {};
    const std::size_t row_size = static_cast<std::size_t>(width) * 4U;
    if (static_cast<std::size_t>(height) > (std::numeric_limits<std::size_t>::max() - pixel_frame_header_size) / row_size)
        return {};
    const std::size_t pixel_bytes = row_size * height;
    std::string frame(pixel_frame_header_size + pixel_bytes, '\0');
    frame[0] = 'R';
    frame[1] = 'V';
    frame[2] = 'P';
    frame[3] = '1';
    write_u32_le(frame.data() + 4, width);
    write_u32_le(frame.data() + 8, height);
    write_u32_le(frame.data() + 12, static_cast<std::uint32_t>(row_size));
    char* output = frame.data() + pixel_frame_header_size;
    for (std::uint32_t y = 0; y < height; ++y) {
        const auto* row = data + static_cast<std::size_t>(y) * stride;
        std::memcpy(output + static_cast<std::size_t>(y) * row_size, row, row_size);
    }
    return frame;
}
}