/// Types for the BLK_BOX NOW pub protocol

#ifndef _BBNOW_PUB_H
#define _BBNOW_PUB_H

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

#include "bb_expantions.hpp"

///////////////////////////////////////
// (1) DISCOVERY                    //
/////////////////////////////////////

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

///////////////////////////////////////
// PUB PACKET                       //
/////////////////////////////////////

/// The packet type for `BBNowPubPacket`s.
enum class BBNowPubPacketType: uint16_t {
    NONE = 0,
    DISCOVERY = 1,
    MAX = 1,
};

/// The data field for the packet
union BlkBoxNowPubPacketData {
    BlkBoxNowPubDiscoveryData discovery;
};

struct BBNowPubPacket {
    const static uint32_t PUB_MAGIC_NUMBER = 0x6262'6E70;
    // DISCOVERY packet size
    const static size_t DISCOVERY_PACKET_SIZE = sizeof(PUB_MAGIC_NUMBER) + sizeof(BBNowPubPacketType) + sizeof(BlkBoxNowPubDiscoveryData);
    static_assert(DISCOVERY_PACKET_SIZE == 8, "Discovery packet should be 8 bytes");

    /// The type of packet this is.
    BBNowPubPacketType 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.
    /// 
    /// Returns the number of bytes written into the buffer.
    size_t serialize_into(std::vector<uint8_t>& buf);
    /// Deserializes a packet from the given bytes.
    static std::optional<BBNowPubPacket> deserialize(std::span<const uint8_t> bytes);

    /// Constructs an empty packet.
    BBNowPubPacket() = default;
    /// Constructs a new `Discovery` type packet with the given data.
    static BBNowPubPacket new_discovery(BlkBoxNowPubDiscoveryData data);
};

#endif /* _BBNOW_PUB_H */