include/guid.hpp

#pragma once

#include <array>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <tuple>

namespace uefi
{
// https://uefi.org/specs/UEFI/2.10/Apx_A_GUID_and_Time_Formats.html?highlight=guid#guid-and-time-formats
typedef struct __attribute__((packed)) Guid
{
    uint32_t timeLow;
    uint16_t timeMid;
    uint16_t timeHiAndVersion;
    std::array<uint8_t, 8> bytes;

    constexpr Guid()
    {}

    constexpr Guid(const uint32_t timeLowIn, const uint16_t timeMidIn,
                   const uint16_t timeHiAndVersionIn,
                   const std::array<uint8_t, 8> bytesIn) :
        timeLow(timeLowIn), timeMid(timeMidIn),
        timeHiAndVersion(timeHiAndVersionIn), bytes(bytesIn)
    {}

    constexpr bool operator==(const Guid& rhs) const
    {
        return std::tie(timeLow, timeMid, timeHiAndVersion, bytes) ==
               std::tie(rhs.timeLow, rhs.timeMid, rhs.timeHiAndVersion,
                        rhs.bytes);
    }
} guid_t;

// Ensure the compiler packs the Guid correctly.
static_assert(offsetof(Guid, timeLow) == 0, "Incorrect timeLow offset");
static_assert(offsetof(Guid, timeMid) == 4, "Incorrect timeMid offset");
static_assert(offsetof(Guid, timeHiAndVersion) == 6,
              "Incorrect timeHiAndVersion offset");
static_assert(offsetof(Guid, bytes) == 8, "Incorrect bytes offset");
} // namespace uefi