json-helpers.hpp

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/* This file is part of SOMHunter.
 *
 * Copyright (C) 2021 Frantisek Mejzlik <frankmejzlik@protonmail.com>
 *                    Mirek Kratochvil <exa.exa@gmail.com>
 *                    Patrik Vesely <prtrikvesely@gmail.com>
 *
 * SOMHunter 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 2 of the License, or (at your option)
 * any later version.
 *
 * SOMHunter 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
 * SOMHunter. If not, see <https://www.gnu.org/licenses/>.
 */
 
#ifndef JSON_HELPERS_H_
#define JSON_HELPERS_H_
 
#include <sstream>
// ---
#include <nlohmann/json.hpp>
// ---
#include "common.h"
 
using namespace nlohmann;
 
namespace sh {
 
inline void require_value(const json& json, const std::string& msg = "Missing JSON value") {
    if (json.is_null()) {
        SHLOG_E_THROW(msg);
    }
}
 
inline void require_key(const json& json, const std::string& key) {
    std::string msg{ "Missing JSON key: " + key };
    if (!json.contains(key)) {
        SHLOG_E_THROW(msg);
    }
    require_value(json[key], msg);
}
 
template <typename T_>
inline T_ optional_value_or(const json& j, const std::string& key, const T_& or_val) {
    if (j[key].is_null()) {
        return or_val;
    } else {
        return j[key].get<T_>();
    }
}
 
template <>
inline std::string optional_value_or(const json& j, const std::string& key, const std::string& or_val) {
    if (j[key].is_null() || j[key].get<std::string>().empty()) {
        return or_val;
    }
    return j[key].get<std::string>();
}
 
template <typename T_>
inline std::optional<T_> optional_value(const json& j, const std::string& key) {
    if (j[key].is_null()) {
        return std::nullopt;
    }
    return std::optional<T_>{ j[key].get<T_>() };
}
 
template <>
inline std::optional<std::string> optional_value(const json& j, const std::string& key) {
    if (j[key].is_null() || j[key].get<std::string>().empty()) {
        return std::nullopt;
    }
    return std::optional<std::string>{ j[key].get<std::string>() };
}
 
template <typename T_>
inline T_ require_value(const json& json, const std::string& key) {
    require_key(json, key);
 
    return static_cast<T_>(json[key].get<T_>());
}
 
inline json wrap_and_parse(std::stringstream& in_stream) {
    std::string s{ in_stream.str() };
 
    if (s[0] == ',') {
        s[0] = ' ';
    }
 
    return json::parse("[" + s + "]");
}
 
}  // namespace sh
 
#endif  // JSON_HELPERS_H_