/**
	This file is a part of rexy's general purpose library
	Copyright (C) 2020-2022 rexy712

	This program 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.

	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 General Public License for more details.

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

#ifdef _MSC_VER
	//Disable warning from msvc for not using fopen_s
	//which is not standard in c++ as of c++23, though it is in c since c11.
	#define _CRT_SECURE_NO_WARNINGS
#endif

#include "rexy/filerd.hpp"

#include <cstdio> //fopen, fclose
#include <utility> //exchange, swap
#include <type_traits>

namespace rexy{

	filerd::filerd(const char* f, const char* mode)noexcept:
		m_fp(std::fopen(f, mode)){}
	filerd::~filerd(void)noexcept{
		if(m_fp)
			std::fclose(m_fp);
	}

	void filerd::reset(std::FILE* fp)noexcept{
		if(m_fp)
			std::fclose(m_fp);
		m_fp = fp;
	}
	std::FILE* filerd::release(void)noexcept{
		return std::exchange(m_fp, nullptr);
	}
	std::size_t filerd::length(void)noexcept{
		if(!m_fp)
			return 0;
		std::size_t tmp, ret;
		tmp = std::ftell(m_fp);
		std::fseek(m_fp, 0, SEEK_END);
		ret = std::ftell(m_fp);
		std::fseek(m_fp, long(tmp), SEEK_SET);
		return ret;
	}
	std::size_t filerd::position(void)const noexcept{
		return std::ftell(m_fp);
	}
	void filerd::rewind(std::size_t pos)noexcept{
		std::fseek(m_fp, long(pos), SEEK_SET);
	}

	filerd::operator std::FILE*(void)noexcept{
		return m_fp;
	}
	filerd::operator const std::FILE*(void)const noexcept{
		return m_fp;
	}
	std::FILE* filerd::get(void)noexcept{
		return m_fp;
	}
	const std::FILE* filerd::get(void)const noexcept{
		return m_fp;
	}
	filerd::operator bool(void)const noexcept{
		return m_fp;
	}

	std::size_t filerd::read(char* dest, std::size_t bytes)noexcept{
		return std::fread(dest, 1, bytes, m_fp);
	}
	rexy::string filerd::read(std::size_t bytes)noexcept{
		rexy::string ret;
		char* tmp = ret.allocator().allocate(bytes);
		std::size_t written = read(tmp, bytes);
		ret.reset(tmp, written);
		return ret;
	}
	rexy::string filerd::readln(std::size_t max)noexcept{
		rexy::string ret;
		int c;
		std::size_t count = 0;
		for(c = std::fgetc(m_fp);c != EOF && c != '\n';c = std::fgetc(m_fp)){
			char ch = c;
			ret.append(&ch, 1);
			if(++count == max)
				break;
		}
		return ret;
	}
	rexy::buffer<char> filerd::read_bin(std::size_t bytes)
		noexcept(std::is_nothrow_constructible<rexy::buffer<char>, char*, std::size_t>::value)
	{
		rexy::buffer<char> ret{bytes};
		std::size_t written = read(ret.data(), bytes);
		ret.set_size(written);
		return ret;
	}
	std::size_t filerd::write(const char* c, std::size_t bytes)noexcept{
		return std::fwrite(c, 1, bytes, m_fp);
	}
	std::size_t filerd::write(rexy::string_view c)noexcept{
		return write(c.data(), c.length());
	}

}