//----------------------------------------------------------------------------- 
//     ___                      __ _       _
//    / _ \__ _ _ __ ___  ___  / /(_)_ __ | | __
//   / /_)/ _` | '__/ __|/ _ \/ / | | '_ \| |/ /
//  / ___/ (_| | |  \__ \  __/ /__| | | | |   <
//  \/    \__,_|_|  |___/\___\____/_|_| |_|_|\_\ .
//
//----------------------------------------------------------------------------- 
// Author: Kurt Sassenrath
// Module: Proto
//
// Message type definitions for the parselink protocol.
//
// Copyright (c) 2023 Kurt Sassenrath.
//
// License TBD.
//----------------------------------------------------------------------------- 
#ifndef message_0c61530748b9f966
#define message_0c61530748b9f966

#include <span>
#include <string_view>
#include <cstdint>

#include <tl/expected.hpp>
#include <variant>

namespace parselink {
namespace proto {

// Parselink messages are encoded with MessagePack and take the form of:
// | magic | size | content |
//      - [magic] is the string "prs", in "fixstr" format.
//      - [size] is the size of the message, not including this header.
//      - [content] is [size] bytes of MessagePack data, including the
//        specific type of message presented.
// This may be revised in the future. The header could remain as msgpack, or
// switch to something hand-crafted for saving bits.

struct error_message {
    std::uint32_t code;                 // An error code
    std::string_view what;              // A string
};

// C->S: Request to (re)connect.
struct connect_message {
    std::uint32_t user_id;              // The user id.
    std::uint32_t version;              // The version of the client.
    std::span<std::byte> session_token; // An optional existing session token.
};

// S->C: Challenge to authenticate client as user_id
struct challenge_message {
    std::uint32_t version;
    std::span<std::byte> challenge;
};

// C->S: Calculated response to a challenge.
struct response_message {
    std::span<std::byte> response;
};

// S->C: Session token.
struct session_established_message {
    std::span<std::byte> session_token;
};

struct parser_data_message {
    std::string_view opts;
    std::span<std::byte> payload;
};

} // namespace message
} // namespace parselink

#endif // message_0c61530748b9f966