#pragma once

#include "macro_map.h"

#include <cassert>
#include <memory>
#include <string>
#include <type_traits>
#include <vector>
#include <functional>
#include <map>
#include <algorithm>

#include "optionalVersion.h"

struct AbsolutePath;

enum class SerializeFormat { Json, MessagePack };

// A tag type that can be used to write `null` to json.
struct JsonNull
{
        void swap(JsonNull& arg) noexcept;
};



class Reader {
public:
        virtual ~Reader() {}
        virtual SerializeFormat Format() const = 0;

        virtual bool IsBool() = 0;
        virtual bool IsNull() = 0;
        virtual bool IsArray() = 0;
        virtual bool IsInt() = 0;
        virtual bool IsInt64() = 0;
        virtual bool IsUint64() = 0;
        virtual bool IsDouble() = 0;
    virtual bool IsNumber() = 0;
    virtual bool IsString() = 0;

        virtual void GetNull() = 0;
        virtual bool GetBool() = 0;
        virtual int GetInt() = 0;
        virtual uint32_t GetUint32() = 0;
        virtual int64_t GetInt64() = 0;
        virtual uint64_t GetUint64() = 0;
        virtual double GetDouble() = 0;
        virtual std::string GetString() = 0;

        virtual bool HasMember(const char* x) = 0;
        virtual std::unique_ptr<Reader> operator[](const char* x) = 0;
        virtual void IterMap( std::function<void(const char*, Reader&)> fn) = 0;
        virtual void IterArray(std::function<void(Reader&)> fn) = 0;
        virtual void DoMember(const char* name, std::function<void(Reader&)> fn) = 0;
        virtual std::string ToString() const = 0;
};



class Writer {
public:
        virtual ~Writer() {}
        virtual SerializeFormat Format() const = 0;

        virtual void Null() = 0;
        virtual void Bool(bool x) = 0;
        virtual void Int(int x) = 0;
        virtual void Uint32(uint32_t x) = 0;
        virtual void Int64(int64_t x) = 0;
        virtual void Uint64(uint64_t x) = 0;
        virtual void Double(double x) = 0;
        virtual void String(const char* x) = 0;
        virtual void String(const char* x, size_t len) = 0;
        virtual void StartArray(size_t) = 0;
        virtual void EndArray() = 0;
        virtual void StartObject() = 0;
        virtual void EndObject() = 0;
        virtual void Key(const char* name) = 0;
};



struct optionals_mandatory_tag {};

#define REFLECT_MEMBER_START() ReflectMemberStart(visitor, value)
#define REFLECT_MEMBER_END() ReflectMemberEnd(visitor, value);
#define REFLECT_MEMBER_END1(value) ReflectMemberEnd(visitor, value);
#define REFLECT_MEMBER(name) ReflectMember(visitor, #name, value.name)
#define REFLECT_MEMBER_OPTIONALS(name) \
  ReflectMember(visitor, #name, value.name, optionals_mandatory_tag{})
#define REFLECT_MEMBER2(name, value) ReflectMember(visitor, name, value)

#define MAKE_REFLECT_TYPE_PROXY(type_name) \
  MAKE_REFLECT_TYPE_PROXY2(type_name, std::underlying_type<type_name>::type)
#define MAKE_REFLECT_TYPE_PROXY2(type, as_type)       \
  inline void Reflect(Reader& visitor, type& value) { \
    as_type value0;                                   \
    ::Reflect(visitor, value0);                       \
    value = static_cast<type>(value0);                \
  }                                                   \
  inline void Reflect(Writer& visitor, type& value) { \
    auto value0 = static_cast<as_type>(value);        \
    ::Reflect(visitor, value0);                       \
  }

#define _MAPPABLE_REFLECT_MEMBER(name) REFLECT_MEMBER(name);
#define _MAPPABLE_REFLECT_MEMBER_OPTIONALS(name) REFLECT_MEMBER_OPTIONALS(name);

#define MAKE_REFLECT_EMPTY_STRUCT(type, ...)     \
  template <typename TVisitor>                   \
  void Reflect(TVisitor& visitor, type& value) { \
    REFLECT_MEMBER_START();                      \
    REFLECT_MEMBER_END();                        \
  }

#define MAKE_REFLECT_STRUCT(type, ...)               \
  template <typename TVisitor>                       \
  void Reflect(TVisitor& visitor, type& value) {     \
    REFLECT_MEMBER_START();                          \
    MACRO_MAP(_MAPPABLE_REFLECT_MEMBER, __VA_ARGS__) \
    REFLECT_MEMBER_END();                            \
  }


#define _MAPPABLE_SWAP_MEMBER(name)  std::swap(name,arg.name);

#define  MAKE_SWAP_METHOD(type, ...)                    \
void swap(type& arg) noexcept{                  \
        MACRO_MAP(_MAPPABLE_SWAP_MEMBER, __VA_ARGS__) \
}

#define MAKE_REFLECT_STRUCT_OPTIONALS_MANDATORY(type, ...)     \
  template <typename TVisitor>                                 \
  void Reflect(TVisitor& visitor, type& value) {               \
    REFLECT_MEMBER_START();                                    \
    MACRO_MAP(_MAPPABLE_REFLECT_MEMBER_OPTIONALS, __VA_ARGS__) \
    REFLECT_MEMBER_END();                                      \
  }

// clang-format off
// Config has many fields, we need to support at least its number of fields.
#define NUM_VA_ARGS_IMPL(_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20,_21,_22,_23,_24,_25,_26,_27,_28,_29,_30,N,...) N
#define NUM_VA_ARGS(...) NUM_VA_ARGS_IMPL(__VA_ARGS__,30,29,28,27,26,25,24,23,22,21,20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1)
// clang-format on

#define _MAPPABLE_REFLECT_ARRAY(name) Reflect(visitor, value.name);

// Reflects the struct so it is serialized as an array instead of an object.
// This currently only supports writers.
#define MAKE_REFLECT_STRUCT_WRITER_AS_ARRAY(type, ...) \
  inline void Reflect(Writer& visitor, type& value) {  \
    visitor.StartArray(NUM_VA_ARGS(__VA_ARGS__));      \
    MACRO_MAP(_MAPPABLE_REFLECT_ARRAY, __VA_ARGS__)    \
    visitor.EndArray();                                \
  }

//// Elementary types

void Reflect(Reader& visitor, uint8_t& value);
void Reflect(Writer& visitor, uint8_t& value);

void Reflect(Reader& visitor, short& value);
void Reflect(Writer& visitor, short& value);

void Reflect(Reader& visitor, unsigned short& value);
void Reflect(Writer& visitor, unsigned short& value);

void Reflect(Reader& visitor, int& value);
void Reflect(Writer& visitor, int& value);

void Reflect(Reader& visitor, unsigned& value);
void Reflect(Writer& visitor, unsigned& value);

void Reflect(Reader& visitor, long& value);
void Reflect(Writer& visitor, long& value);

void Reflect(Reader& visitor, unsigned long& value);
void Reflect(Writer& visitor, unsigned long& value);

void Reflect(Reader& visitor, long long& value);
void Reflect(Writer& visitor, long long& value);

void Reflect(Reader& visitor, unsigned long long& value);
void Reflect(Writer& visitor, unsigned long long& value);

void Reflect(Reader& visitor, double& value);
void Reflect(Writer& visitor, double& value);

void Reflect(Reader& visitor, bool& value);
void Reflect(Writer& visitor, bool& value);

void Reflect(Reader& visitor, std::string& value);
void Reflect(Writer& visitor, std::string& value);

void Reflect(Reader& visitor, JsonNull& value);
void Reflect(Writer& visitor, JsonNull& value);

void Reflect(Reader& visitor, SerializeFormat& value);
void Reflect(Writer& visitor, SerializeFormat& value);

//// Type constructors
template <typename T>
void Reflect(Reader& visitor, optional<T>& value) {
        if (visitor.IsNull()) {
                visitor.GetNull();
                return;
        }
        T real_value;
        Reflect(visitor, real_value);
        value = std::move(real_value);
}
template <typename T>
void Reflect(Writer& visitor, optional<T>& value) {
        if (value)
                Reflect(visitor, *value);
        else
                visitor.Null();
}


template <typename T>
void ReflectMember(Writer& visitor, const char* name, optional<T>& value) {
        // For TypeScript optional property key?: value in the spec,
        // We omit both key and value if value is std::nullopt (null) for JsonWriter
        // to reduce output. But keep it for other serialization formats.
        if (value || visitor.Format() != SerializeFormat::Json) {
                visitor.Key(name);
                Reflect(visitor, value);
        }
}


template <typename T>
void ReflectMember(Writer& visitor,
        const char* name,
        T& value,
        optionals_mandatory_tag) {
        visitor.Key(name);
        Reflect(visitor, value);
}
template <typename T>
void ReflectMember(Reader& visitor,
        const char* name,
        T& value,
        optionals_mandatory_tag) {
        Reflect(visitor, value);
}

template<class T >
void Reflect(Reader& visitor, std::map<std::string, T>& value)
{
        visitor.IterMap([&](const char* name,Reader& entry) {
                T entry_value;
                Reflect(entry, entry_value);
                value[name]=(std::move(entry_value));
        });
}
template<class _Ty >
void Reflect(Writer& visitor, std::map<std::string, _Ty>& value)
{
        REFLECT_MEMBER_START();
        for (auto& it : value)
        {
                visitor.Key(it.first.c_str());
                Reflect(visitor, it.second);
        }
        REFLECT_MEMBER_END();
}

// std::vector
template <typename T>
void Reflect(Reader& visitor, std::vector<T>& values) {
        visitor.IterArray([&](Reader& entry) {
                T entry_value;
                Reflect(entry, entry_value);
                values.push_back(std::move(entry_value));
                });
}


template <typename T>
void Reflect(Writer& visitor, std::vector<T>& values) {
        visitor.StartArray(values.size());
        for (auto& value : values)
                Reflect(visitor, value);
        visitor.EndArray();
}

// ReflectMember

inline void DefaultReflectMemberStart(Writer& visitor) {
        visitor.StartObject();
}
inline void DefaultReflectMemberStart(Reader& visitor) {}

template <typename T>
bool ReflectMemberStart(Reader& visitor, T& value) {
        return false;
}
template <typename T>
bool ReflectMemberStart(Writer& visitor, T& value) {
        visitor.StartObject();
        return true;
}

template <typename T>
void ReflectMemberEnd(Reader& visitor, T& value) {}
template <typename T>
void ReflectMemberEnd(Writer& visitor, T& value) {
        visitor.EndObject();
}

template <typename T>
void ReflectMember(Reader& visitor, const char* name, T& value) {
        visitor.DoMember(name, [&](Reader& child) { Reflect(child, value); });
}
template <typename T>
void ReflectMember(Writer& visitor, const char* name, T& value) {
        visitor.Key(name);
        Reflect(visitor, value);
}

template<class _Ty1, class _Ty2>
void Reflect(Writer& visitor, std::pair<  optional<_Ty1>, optional<_Ty2> >& value)
{
        if (value.first)
        {
                Reflect(visitor, value.first);
        }
        else
        {
                Reflect(visitor, value.second);
        }
}
template<class _Ty2>
void Reflect(Reader& visitor, std::pair<  optional<bool>, optional<_Ty2> >& value)
{
        if(visitor.IsBool())
        {
                Reflect(visitor, value.first);
                return;
        }

        Reflect(visitor, value.second);
}
template<class _Ty2>
void Reflect(Reader& visitor, std::pair<  optional<std::string>, optional<_Ty2> >& value)
{
        if (visitor.IsString())
        {
                Reflect(visitor, value.first);
                return;
        }

        Reflect(visitor, value.second);
}


template<class _Ty1, class _Ty2>
void Reflect(Reader& visitor, std::pair<  optional<_Ty1>, optional<_Ty2> >& value)
{
        try
        {
                Reflect(visitor, value.second);
        }
        catch (...)
        {
                Reflect(visitor, value.first);
        }
}