picomap/firmware/include/wire.h

#pragma once
#include <array>
#include <cstdint>
#include <string>
#include <tuple>
#include <vector>
#include "msgpack.h"
#include "halfsiphash.h"
#include "static_vector.h"

struct Envelope {
    static constexpr int8_t ext_id = 0;
    uint32_t message_id;
    uint32_t checksum;
    std::vector<uint8_t> payload;
    auto as_tuple() const { return std::tie(message_id, checksum, payload); }
    auto as_tuple() { return std::tie(message_id, checksum, payload); }
};

struct DeviceError {
    static constexpr int8_t ext_id = 1;
    uint32_t code;
    std::string message;
    auto as_tuple() const { return std::tie(code, message); }
    auto as_tuple() { return std::tie(code, message); }
};

struct RequestPICOBOOT {
    static constexpr int8_t ext_id = 2;
    auto as_tuple() const { return std::tie(); }
    auto as_tuple() { return std::tie(); }
};

struct ResponsePICOBOOT {
    static constexpr int8_t ext_id = 3;
    auto as_tuple() const { return std::tie(); }
    auto as_tuple() { return std::tie(); }
};

struct RequestInfo {
    static constexpr int8_t ext_id = 4;
    auto as_tuple() const { return std::tie(); }
    auto as_tuple() { return std::tie(); }
};

struct ResponseInfo {
    static constexpr int8_t ext_id = 5;
    std::array<uint8_t, 8> board_id;
    std::array<uint8_t, 6> mac;
    std::array<uint8_t, 4> ip;
    std::string firmware_name;
    auto as_tuple() const { return std::tie(board_id, mac, ip, firmware_name); }
    auto as_tuple() { return std::tie(board_id, mac, ip, firmware_name); }
};

struct RequestLog {
    static constexpr int8_t ext_id = 6;
    auto as_tuple() const { return std::tie(); }
    auto as_tuple() { return std::tie(); }
};

struct LogEntry {
    uint32_t timestamp_us;
    std::string message;
    auto as_tuple() const { return std::tie(timestamp_us, message); }
    auto as_tuple() { return std::tie(timestamp_us, message); }
};

struct ResponseLog {
    static constexpr int8_t ext_id = 7;
    std::vector<LogEntry> entries;
    auto as_tuple() const { return std::tie(entries); }
    auto as_tuple() { return std::tie(entries); }
};

struct RequestTest {
    static constexpr int8_t ext_id = 127;
    std::string name;
    auto as_tuple() const { return std::tie(name); }
    auto as_tuple() { return std::tie(name); }
};

struct ResponseTest {
    static constexpr int8_t ext_id = 126;
    bool pass;
    std::vector<std::string> messages;
    auto as_tuple() const { return std::tie(pass, messages); }
    auto as_tuple() { return std::tie(pass, messages); }
};

static constexpr uint8_t hash_key[8] = {};

struct DecodedMessage {
    uint32_t message_id;
    int8_t type_id;
    std::vector<uint8_t> payload;
};

inline std::vector<uint8_t> pack_envelope(uint32_t message_id, const std::vector<uint8_t> &payload) {
    uint32_t checksum = halfsiphash::hash32(payload.data(), payload.size(), hash_key);
    msgpack::packer p;
    p.pack(Envelope{message_id, checksum, payload});
    return p.get_payload();
}

template <typename T>
inline std::vector<uint8_t> encode_response(uint32_t message_id, const T &msg) {
    msgpack::packer inner;
    inner.pack(msg);
    return pack_envelope(message_id, inner.get_payload());
}

inline msgpack::result<DecodedMessage> try_decode(const uint8_t *data, size_t len) {
    msgpack::parser p(data, static_cast<int>(len));

    Envelope env;
    auto r = msgpack::unpack(p, env);
    if (!r) return std::unexpected(r.error());

    uint32_t expected = halfsiphash::hash32(env.payload.data(), env.payload.size(), hash_key);
    if (env.checksum != expected) return std::unexpected(msgpack::error_code::invalid);

    msgpack::parser inner(env.payload.data(), static_cast<int>(env.payload.size()));
    if (!inner.is_ext()) return std::unexpected(msgpack::error_code::type_error);
    auto ext = inner.get_ext();
    if (!ext) return std::unexpected(ext.error());

    auto& [type_id, ext_data] = *ext;
    return DecodedMessage{env.message_id, type_id,
        std::vector<uint8_t>(reinterpret_cast<const uint8_t*>(ext_data.data()),
                             reinterpret_cast<const uint8_t*>(ext_data.data()) + ext_data.size())};
}

template <size_t N>
inline msgpack::result<DecodedMessage> try_decode(const static_vector<uint8_t, N> &buf) {
    return try_decode(buf.data(), buf.size());
}

template <typename T>
inline msgpack::result<T> decode_response(const uint8_t *data, size_t len) {
    msgpack::parser p(data, static_cast<int>(len));

    Envelope env;
    auto r = msgpack::unpack(p, env);
    if (!r) return std::unexpected(r.error());

    uint32_t expected = halfsiphash::hash32(env.payload.data(), env.payload.size(), hash_key);
    if (env.checksum != expected) return std::unexpected(msgpack::error_code::invalid);

    msgpack::parser inner(env.payload.data(), static_cast<int>(env.payload.size()));
    T out;
    auto r2 = msgpack::unpack(inner, out);
    if (!r2) return std::unexpected(r2.error());
    return out;
}

inline std::vector<uint8_t> encode_request(uint32_t message_id, const auto &msg) {
    msgpack::packer inner;
    inner.pack(msg);
    return pack_envelope(message_id, inner.get_payload());
}