TSAJSON.h

#ifndef TSA_JSON__INCLUDED
#define TSA_JSON__INCLUDED

/* json11
*
* json11 is a tiny JSON library for C++11, providing JSON parsing and serialization.
*
* The core object provided by the library is json11::Json. A Json object represents any JSON
* value: null, bool, number (int or double), string (std::string), array (std::vector), or
* object (std::map).
*
* Json objects act like values: they can be assigned, copied, moved, compared for equality or
* order, etc. There are also helper methods Json::dump, to serialize a Json to a string, and
* Json::parse (static) to parse a std::string as a Json object.
*
* Internally, the various types of Json object are represented by the JsonValue class
* hierarchy.
*
* A note on numbers - JSON specifies the syntax of number formatting but not its semantics,
* so some JSON implementations distinguish between integers and floating-point numbers, while
* some don't. In json11, we choose the latter. Because some JSON implementations (namely
* Javascript itself) treat all numbers as the same type, distinguishing the two leads
* to JSON that will be *silently* changed by a round-trip through those implementations.
* Dangerous! To avoid that risk, json11 stores all numbers as double internally, but also
* provides integer helpers.
*
* Fortunately, double-precision IEEE754 ('double') can precisely store any integer in the
* range +/-2^53, which includes every 'int' on most systems. (Timestamps often use int64
* or long long to avoid the Y2038K problem; a double storing microseconds since some epoch
* will be exact for +/- 275 years.)
*/

/* Copyright (c) 2013 Dropbox, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/

#pragma once

#include <string>
#include <vector>
#include <map>
#include <memory>
#include <initializer_list>

#include "TSATypeDef.h"
#include "TSATime.h"

namespace tsa{

    class json_value;

    class json final {
    public:

        enum Type {
            NUL, NUMBER, BOOL, STRING, ARRAY, OBJECT
        };

        // Array and object typedefs
        typedef std::vector<json> array;
        typedef std::map<std::string, json> object;

        // Constructors for the various types of JSON value.
        //json(const json::object&);
        json() noexcept;                // NUL
        json(std::nullptr_t) noexcept;  // NUL
        json(double value);             // NUMBER
        json(int value);                // NUMBER
        json(int64_t value);            // NUMBER
        json(uint64_t value);           // NUMBER
        json(bool value);               // BOOL
        json(const date_time& value);   // STRING
        json(const date& value);        // STRING
        json(const std::string &value); // STRING
        json(std::string &&value);      // STRING
        json(const char * value);       // STRING
        json(const array &values);      // ARRAY
        json(array &&values);           // ARRAY
        json(const object &values);     // OBJECT
        json(object &&values);          // OBJECT
        explicit json(const variant&);

        template <class T, class = decltype(&T::to_json)>
        json(const T & t) : json(t.to_json()) {}

        template <class M, typename std::enable_if<
            std::is_constructible<std::string, typename M::key_type>::value
            && std::is_constructible<json, typename M::mapped_type>::value, int>::type = 0>
            json(const M & m) : json(object(m.begin(), m.end())) {}

        template <class V, typename std::enable_if<
            std::is_constructible<json, typename V::value_type>::value, int>::type = 0>
            json(const V & v) : json(array(v.begin(), v.end())) {}

        json(void *) = delete;

        Type type() const;

        bool is_defined()   const { return type() != NUL; }
        bool is_null()   const { return type() == NUL; }
        bool is_number() const { return type() == NUMBER; }
        bool is_bool()   const { return type() == BOOL; }
        bool is_string() const { return type() == STRING; }
        bool is_array()  const { return type() == ARRAY; }
        bool is_object() const { return type() == OBJECT; }


        template<typename T> T get(void) const;

        /*
        * @brief    Return the enclosed value if this is a number, 0 otherwise. Note that json11 does not
        *  distinguish between integer and non-integer numbers - number_value() and int_value()
        *  can both be applied to a NUMBER-typed object.
        * @return   The total number of value.
        */
        double number_value() const;
        //
        //double get_number()const;
        double float64()const;

        int int_value(void) const;
        int int32(void)const;

        int64_t int64(void)const{
             double value = float64();
             int64_t integer = (int64_t)value;
             if ((double)integer != value)
                 throw std::exception("json cannot return number as int64_t, conversion error");
             return integer;
         }
        
        tsa::identifier_t id(void)const {
            return int64();
        }
        int64_t uint64(void)const{
             double value = float64();
             uint64_t integer = (int64_t)value;
             if ((double)integer != value)
                 throw std::exception("json cannot return number as uint64_t, conversion error");
             return integer;
         }
        bool bool_value(void) const;
        bool boolean(void)const;
        const std::string& string_value(void) const;
        //
        //const std::string& get_string(void) const;
        const std::string& str(void) const;

        variant to_variant(void)const;

        /*
        * @brief    Return the enclosed std::vector if this is an array, or an empty vector otherwise.
        * @return   An array&amp;
        */
        const array& array_items(void) const;
        const array& get_array(void) const{ return array_items(); }
        /*
        * @brief    Return the enclosed std::map if this is an object, or an empty map otherwise.
        * @return   An object&amp;
        */
        const object& object_items(void) const;
        const object& get_object(void) const{ return object_items(); }

        const json& operator[](size_t i) const;

        const json& operator[](const std::string &key) const;

    public:

        explicit operator double(void) const { return float64(); }
        explicit  operator int(void) const { return int32(); }
        explicit  operator int64_t (void) const { return int64(); }
        // @brief Returns value as an uint64_t.
        explicit  operator uint64_t (void) const { return uint64(); }
        explicit  operator bool(void) const { return boolean(); }
        explicit  operator std::string(void) const { return str(); }
        explicit  operator date(void) const {tsa::date d; d.set_from_iso_string(str()); return d;}
        explicit  operator date_time(void) const { tsa::date_time t; t.set_from_iso_string(str()); return t; }
    public:
        void dump(std::string &out) const;
        std::string to_string(void) const;

        void print(std::ostream& stream)const;

        void print_formated(std::ostream& stream)const;

        static json parse(const std::string & in, std::string & err);

        static json parse(const std::string & in);
        static json parse(const char * in, std::string & err) {
            if (in) {
                return parse(std::string(in), err);
            }
            else {
                err = "null input";
                return nullptr;
            }
        }

        static std::vector<json> parse_multi(const std::string & in, std::string & err);

        bool operator== (const json &rhs) const;
        bool operator<  (const json &rhs) const;
        bool operator!= (const json &rhs) const { return !(*this == rhs); }
        bool operator<= (const json &rhs) const { return !(rhs < *this); }
        bool operator>(const json &rhs) const { return  (rhs < *this); }
        bool operator>= (const json &rhs) const { return !(*this < rhs); }

        typedef std::initializer_list<std::pair<std::string, Type>> shape;
        bool has_shape(const shape & types, std::string & err) const;

    private:
        std::shared_ptr<json_value> m_ptr;
    public:
        void insert(const std::string& key, const json& value);
        bool has_key(const std::string& key)const;
        void push_back(const json& value);
    };

    template<> double json::get<double>(void) const;
    template<> int json::get<int>(void) const;
    template<> unsigned json::get<unsigned>(void) const;
    template<> int64_t json::get<int64_t>(void) const;
    template<> uint64_t json::get<uint64_t>(void) const;
    template<> std::string  json::get<std::string>(void) const;
    template<> tsa::date  json::get<tsa::date>(void) const;
    template<> tsa::date_time  json::get<tsa::date_time>(void) const;
    template<> bool  json::get<bool>(void) const;

    // Internal class hierarchy - JsonValue objects are not exposed to users of this API.
    class json_value {
    protected:
        friend class json;
        friend class JsonInt;
        friend class JsonDouble;
        virtual json::Type type() const = 0;
        virtual bool equals(const json_value * other) const = 0;
        virtual bool less(const json_value * other) const = 0;
        virtual void dump(std::string &out) const = 0;
        virtual double number_value() const;
        virtual int int_value() const;
        virtual bool bool_value() const;
        virtual const std::string &string_value() const;
        virtual const json::array &array_items() const;
        virtual const json& operator[](size_t i) const;
        virtual const json::object &object_items() const;
        virtual const json& operator[](const std::string &key) const;
        virtual ~json_value() {}
    };

}// tsa


#endif