xmmJson.hpp

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/*
 * xmmJson.hpp
 *
 * Set of utility functions for JSON I/O
 *
 * Contact:
 * - Jules Francoise <jules.francoise@ircam.fr>
 *
 * This code has been initially authored by Jules Francoise
 * <http://julesfrancoise.com> during his PhD thesis, supervised by Frederic
 * Bevilacqua <href="http://frederic-bevilacqua.net>, in the Sound Music
 * Movement Interaction team <http://ismm.ircam.fr> of the
 * STMS Lab - IRCAM, CNRS, UPMC (2011-2015).
 *
 * Copyright (C) 2015 UPMC, Ircam-Centre Pompidou.
 *
 * This File is part of XMM.
 *
 * XMM 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.
 *
 * XMM 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 XMM.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef xmmJson_h
#define xmmJson_h

#include "../../../dependencies/jsoncpp/include/json.h"
#include <fstream>
#include <vector>

namespace xmm {
class Writable {
  public:
    virtual ~Writable() {}


    virtual Json::Value toJson() const = 0;

    virtual void fromJson(Json::Value const& root) = 0;


#ifdef SWIGPYTHON


    void writeFile(char* fileName) const {
        std::ofstream outStream;
        outStream.open(fileName);
        outStream << this->toJson();
        outStream.close();
    }

    void readFile(char* fileName) {
        std::string jsonstring;
        std::ifstream inStream;
        inStream.open(fileName);
        //            inStream.seekg(0, std::ios::end);
        //            jsonstring.reserve(inStream.tellg());
        //            inStream.seekg(0, std::ios::beg);
        //
        //            jsonstring.assign((std::istreambuf_iterator<char>(inStream)),
        //                              std::istreambuf_iterator<char>());
        Json::Value root;
        Json::Reader reader;
        if (reader.parse(inStream, root)) {
            this->fromJson(root);
        } else {
            throw std::runtime_error("Cannot Parse Json File");
        }
        inStream.close();
    }

    std::string __str__() const { return this->toJson().toStyledString(); }

#endif
};

class JsonException : public std::exception {
  public:
    enum class JsonErrorType {
        JsonMissingNode,

        JsonTypeError,

        JsonValueError
    };

    JsonException(JsonErrorType errorType, std::string nodename = "")
        : errorType_(errorType) {
        nodename_.push_back(nodename);
    }

    explicit JsonException(JsonException const& src, std::string nodename)
        : errorType_(src.errorType_), nodename_(src.nodename_) {
        nodename_.push_back(nodename);
    }

    JsonException(JsonException const& src)
        : errorType_(src.errorType_), nodename_(src.nodename_) {}

    JsonException& operator=(JsonException const& src) {
        if (this != &src) {
            errorType_ = src.errorType_;
            nodename_ = src.nodename_;
        }
        return *this;
    }

    virtual const char* what() const throw() {
        std::string message;
        switch (errorType_) {
            case JsonErrorType::JsonMissingNode:
                message = "Json Structure Error: Missing Node";
                break;

            case JsonErrorType::JsonTypeError:
                message = "Json Structure Error: Type Error";
                break;

            case JsonErrorType::JsonValueError:
                message = "Json Structure Error: Value Error";
                break;

            default:
                message = "Json unknown error type";
                break;
        }
        message += " (root";
        for (auto& node : nodename_) message += " > " + node;
        message += ")";
        return message.c_str();
    }

  private:
    JsonErrorType errorType_;

    std::vector<std::string> nodename_;
};

template <typename T>
Json::Value array2json(T const* a, unsigned int n) {
    Json::Value root;
    root.resize(static_cast<Json::ArrayIndex>(n));
    for (int i = 0; i < n; i++) {
        root[i] = a[i];
    }
    return root;
}

template <typename T>
void json2array(Json::Value const& root, T* a, unsigned int n) {
    if (!root.isArray())
        throw JsonException(JsonException::JsonErrorType::JsonTypeError);
    if (root.size() != n)
        throw JsonException(JsonException::JsonErrorType::JsonValueError);
    unsigned int i = 0;
    for (auto it : root) {
        a[i++] = it.asInt();
    }
}

template <>
void json2array(Json::Value const& root, float* a, unsigned int n);
template <>
void json2array(Json::Value const& root, double* a, unsigned int n);
template <>
void json2array(Json::Value const& root, bool* a, unsigned int n);
template <>
void json2array(Json::Value const& root, std::string* a, unsigned int n);

template <typename T>
Json::Value vector2json(std::vector<T> const& a) {
    Json::Value root;
    root.resize(static_cast<Json::ArrayIndex>(a.size()));
    for (int i = 0; i < a.size(); i++) {
        root[i] = a[i];
    }
    return root;
}

template <typename T>
void json2vector(Json::Value const& root, std::vector<T>& a, unsigned int n) {
    if (!root.isArray())
        throw JsonException(JsonException::JsonErrorType::JsonTypeError);
    if (root.size() != n)
        throw JsonException(JsonException::JsonErrorType::JsonValueError);
    unsigned int i = 0;
    for (auto it : root) {
        a[i++] = it.asInt();
    }
}

template <>
void json2vector(Json::Value const& root, std::vector<float>& a,
                 unsigned int n);
template <>
void json2vector(Json::Value const& root, std::vector<double>& a,
                 unsigned int n);
template <>
void json2vector(Json::Value const& root, std::vector<bool>& a, unsigned int n);
template <>
void json2vector(Json::Value const& root, std::vector<std::string>& a,
                 unsigned int n);
}

#endif