/**
	This file is a part of rexy's matrix bot
	Copyright (C) 2019 rexy712

	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero 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 Affero General Public License for more details.

	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef RAII_STRING_HPP
#define RAII_STRING_HPP

#include "raii/string_base.hpp"

#include <new> //operator new/delete
#include <cstring> //memcpy

namespace raii{

	namespace detail{

		class default_allocator
		{
		public:
			static void free(void* data){
				::operator delete(data);
			}
			static void* allocate(size_t size){
				return ::operator new(size);
			}
			static void* copy(const void* c, size_t size){
				char* tmp = reinterpret_cast<char*>(allocate(size));
				memcpy(tmp, c, size-1);
				tmp[size-1] = 0;
				return tmp;
			}
		};

	}

	//new allocated string
	struct string : public string_intermediary<detail::default_allocator>
	{
		string(const string&) = default;
		string(string&&) = default;
		string& operator=(const string&) = default;
		string& operator=(string&&) = default;

		using string_intermediary<detail::default_allocator>::string_intermediary;
		using string_intermediary<detail::default_allocator>::operator=;
	};

	namespace detail{
		size_t _calc_escaped_len(const char* str);
		char _escape_to_letter(char escape);
		size_t _sanitize_json_copy(char* dest, const char* in);

		template<class Tup, size_t I = 0>
		void _js_assign(char* dest, Tup&& t, size_t offset){
			size_t written = _sanitize_json_copy(dest+offset, std::get<I>(t));
			if constexpr(I+2 < std::tuple_size<std::remove_reference_t<Tup>>::value){
				_js_assign<Tup,I+2>(dest, std::forward<Tup>(t), offset+written);
			}
		}
		template<class T, size_t I = 0>
		size_t _calc_escaped_len_all(T&& t){
			size_t len = _calc_escaped_len(std::get<I>(t));
			if constexpr(I+2 < std::tuple_size<std::remove_reference_t<T>>::value){
				len += _calc_escaped_len_all<T,I+2>(std::forward<T>(t));
			}
			return len;
		}
	}
	template<class T, typename std::enable_if<detail::is_string<T>::value && !detail::is_concrete_string<T>::value,void>::type* = nullptr>
	string json_escape(T&& t){
		auto tup = t.get();
		size_t len = detail::_calc_escaped_len_all(tup);
		char* tmp = reinterpret_cast<char*>(string::allocator_type::allocate(len+1));
		detail::_js_assign(tmp, tup, 0);
		tmp[len] = 0;
		return string(tmp, len);
	}
	string json_escape(const string_base& str);
}

#endif