/**
	This file is a part of rexy's general purpose library
	Copyright (C) 2020 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/>.
*/

#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(fopen(f, mode)){}
	filerd::~filerd(void)noexcept{
		if(m_fp)
			fclose(m_fp);
	}

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

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

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

}