/*** This file is part of snapcast Copyright (C) 2014-2024 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 . ***/ #pragma once // local headers #include "common/json.hpp" // standard headers #include // Prefix used in output #define METADATA std::string("metadata") /* * Implement a generic metadata output handler */ using json = nlohmann::json; /* * Base class, prints to stdout */ class MetadataAdapter { public: MetadataAdapter() { reset(); } virtual ~MetadataAdapter() = default; void reset() { msg_ = json{}; } std::string serialize() { return METADATA + ":" + msg_.dump(); } void tag(const std::string& name, const std::string& value) { msg_[name] = value; } std::string operator[](const std::string& key) { try { return msg_[key]; } catch (std::domain_error&) { return std::string(); } } virtual int push() { std::cout << serialize() << "\n"; return 0; } int push(const json& jtag) { msg_ = jtag; return push(); } protected: json msg_; }; /* * Send metadata to stderr as json */ class MetaStderrAdapter : public MetadataAdapter { public: using MetadataAdapter::push; int push() override { std::cerr << serialize() << "\n"; return 0; } };