/**
	This file is a part of rexy's matrix client
	Copyright (C) 2019-2020 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/>.
*/

#include <rexy/string.hpp>

namespace raii{

	namespace detail{

		size_t _calc_escaped_len(const char* str){
			size_t ret = 0;
			for(const char* c = str;*c;++c){
				switch(*c){
				case '\\':
				case '"':
				case '/':
				case '\n':
				case '\r':
				case '\b':
				case '\f':
				case '\t':
					++ret;
					break;
				};
				++ret;
			}
			return ret;
		}
		char _escape_to_letter(char escape){
			switch(escape){
				case '\n':
					return 'n';
				case '\r':
					return 'r';
				case '\b':
					return 'b';
				case '\f':
					return 'f';
				case '\t':
					return 't';
			};
			return '\\';
		}
		size_t _sanitize_json_copy(char* dest, const char* in){
			size_t pos = 0;
			for(const char* c = in;*c;++c){
				switch(*c){
				case '"':
				case '\\':
				case '/':
					dest[pos++] = '\\';
					dest[pos++] = *c;
					break;
				case '\n':
				case '\r':
				case '\b':
				case '\f':
				case '\t':
					dest[pos++] = '\\';
					dest[pos++] = _escape_to_letter(*c);
					break;
				default:
					dest[pos++] = *c;
				};
			}
			dest[pos] = 0;
			return pos;
		}
	}
	rexy::string json_escape(const rexy::string_base& str){
		size_t len = detail::_calc_escaped_len(str.get());
		char* tmp = reinterpret_cast<char*>(rexy::string::allocator_type::allocate(len+1));
		detail::_sanitize_json_copy(tmp, str);
		tmp[len] = 0;
		return rexy::string(tmp, len, len);
	}


	//shamelessly stolen from stackoverflow (of all the things to need to steal)
	size_t intlen(int i){
		if(i >= 100000){
			if(i >= 10000000){
				if(i >= 1000000000) return 10;
				if(i >= 100000000) return 9;
				return 8;
			}
			if(i >= 1000000) return 7;
			return 6;
		}else{
			if(i >= 1000){
				if(i >= 10000) return 5;
				return 4;
			}else{
				if(i >= 100) return 3;
				if(i >= 10) return 2;
				return 1;
			}
		}
	}
	rexy::string itostr(int i){
		if(i == 0)
			return rexy::string("0");
		int place = intlen(i);
		rexy::string ret(place, place);
		char* buf = ret.get();
		buf[place] = 0;
		while(i != 0){
			int rem = i % 10;
			buf[--place] = rem + '0';
			i /= 10;
		}
		return ret;
	}


}