snapcast/common/message/hello.hpp

/***
    This file is part of snapcast
    Copyright (C) 2014-2025  Johannes Pohl

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
***/

#pragma once

// local headers
#include "common/str_compat.hpp"
#include "common/utils.hpp"
#include "json_message.hpp"

// standard headers
#include <optional>
#include <string>


namespace msg
{

/// Hello message
/// Initial message, sent from client to server
class Hello : public JsonMessage
{
public:
    /// Auth info
    struct Auth
    {
        /// c'tor
        Auth() = default;

        /// c'tor construct from json
        explicit Auth(const json& j)
        {
            if (j.contains("scheme"))
                scheme = j["scheme"];
            if (j.contains("param"))
                param = j["param"];
        }

        /// c'tor construct from @p scheme and @p param
        Auth(std::string scheme, std::string param) : scheme(std::move(scheme)), param(std::move(param))
        {
        }

        /// @return serialized to json
        json toJson() const
        {
            json j;
            j["scheme"] = scheme;
            j["param"] = param;
            return j;
        }

        /// the scheme (Basic, Plain, bearer, ...)
        std::string scheme;
        /// the param (base64 encoded "<user>:<password>", "<user>:<password>", token, ...)
        std::string param;
    };

    /// c'tor
    Hello() : JsonMessage(message_type::kHello)
    {
    }

    /// c'tor taking @p macAddress, @p id, @p instance and @p auth info
    Hello(const std::string& mac_address, const std::string& id, size_t instance, std::optional<Auth> auth) : JsonMessage(message_type::kHello)
    {
        msg["MAC"] = mac_address;
        msg["HostName"] = ::getHostName();
        msg["Version"] = VERSION;
        msg["ClientName"] = "Snapclient";
        msg["OS"] = ::getOS();
        msg["Arch"] = ::getArch();
        msg["Instance"] = instance;
        msg["ID"] = id;
        if (auth.has_value())
            msg["Auth"] = auth->toJson();
        msg["SnapStreamProtocolVersion"] = 2;
    }

    /// d'tor
    ~Hello() override = default;

    /// @return the MAC address
    std::string getMacAddress() const
    {
        return msg["MAC"];
    }

    /// @return the host name
    std::string getHostName() const
    {
        return msg["HostName"];
    }

    /// @return the client version
    std::string getVersion() const
    {
        return msg["Version"];
    }

    /// @return the client name (e.g. "Snapclient")
    std::string getClientName() const
    {
        return msg["ClientName"];
    }

    /// @return the OS name
    std::string getOS() const
    {
        return msg["OS"];
    }

    /// @return the CPU architecture
    std::string getArch() const
    {
        return msg["Arch"];
    }

    /// @return the instance id
    int getInstance() const
    {
        return get("Instance", 1);
    }

    /// @return the protocol version
    int getProtocolVersion() const
    {
        return get("SnapStreamProtocolVersion", 1);
    }

    /// @return a unqiue machine ID
    std::string getId() const
    {
        return get("ID", getMacAddress());
    }

    /// @return a unqiue client ID
    std::string getUniqueId() const
    {
        std::string id = getId();
        int instance = getInstance();
        if (instance != 1)
        {
            id = id + "#" + cpt::to_string(instance);
        }
        return id;
    }

    /// @return the auth info
    std::optional<Auth> getAuth() const
    {
        if (!msg.contains("Auth"))
            return std::nullopt;
        return Auth{msg["Auth"]};
    }
};

} // namespace msg