/// Types common across the blk_box ecosystem

#ifndef _BLK_BOX_COMMON_H
#define _BLK_BOX_COMMON_H

#include <cstddef>
#include <stdint.h>
#include <vector>
#include <span>
#include <optional>

/// The different expantions to the BLK_BOX.
enum class BlkBoxExpantion: uint16_t {
    NONE = 0,
    WIRES = 1,
    TENS = 2,
    MAX = 2,
};

/// The packet type for `BlkBoxNowPubPacket`s.
enum class BlkBoxNowPubPacketType: uint8_t {
    NONE = 0,
    DISCOVERY = 1,
    MAX = 1,
};

/// The data associated with the `DISCOVERY` type.
struct BlkBoxNowPubDiscoveryData {
    BlkBoxExpantion expantion_type{};
};

union BlkBoxNowPubPacketData {
    BlkBoxNowPubDiscoveryData discovery;
};

struct BlkBoxNowPubPacket {
    const static uint32_t PUB_MAGIC_NUMBER = 0x8934'DBE3;
    // DISCOVERY packet size
    const static size_t DISCOVERY_PACKET_SIZE = sizeof(PUB_MAGIC_NUMBER) + sizeof(BlkBoxNowPubPacketType) + sizeof(BlkBoxNowPubDiscoveryData);
    static_assert(DISCOVERY_PACKET_SIZE == 7, "Discovery packet should be 7 bytes");


    /// The type of packet this is.
    BlkBoxNowPubPacketType packet_type{};
    /// The data held by the packet.
    BlkBoxNowPubPacketData packet_data{};

    /// The size of the serialized packet (in bytes).
    size_t serialize_size();
    /// Serializes the packet to a vector.
    std::vector<uint8_t> serialize();
    /// Serializes the packet into the given vector.
    size_t serialize_into(std::vector<uint8_t>& buf);
    /// Deserializes a packet from the given bytes.
    static std::optional<BlkBoxNowPubPacket> deserialize(std::span<const uint8_t> bytes);

    /// Constructs an empty packet.
    BlkBoxNowPubPacket() = default;
    static BlkBoxNowPubPacket new_discovery(BlkBoxNowPubDiscoveryData data);
};

#endif /* _BLK_BOX_COMMON_H */