//
// fdiobuf.cpp
// libscio
//
// Created by Bob Polis at 2020-02-14
// Copyright (c) 2020 SwiftCoder. All rights reserved.
//

#include "libscio.hpp"

#ifdef _MSC_VER
#include <io.h>
#else
#include <unistd.h>
#endif

std::streambuf::int_type sc::io::fdiobuf::underflow() {
	int num = ::read(_fd, &_ch, 1);
	if (num <= 0) {
		return EOF;
	}
	setg(&_ch, &_ch, &_ch + 1);
	return _ch;
}

std::streamsize sc::io::fdiobuf::xsgetn(char* s, std::streamsize n) {
	return ::read(_fd, s, n);
}

std::streambuf::int_type sc::io::fdiobuf::overflow(std::streambuf::int_type c) {
    if (c != EOF) {
        int res;
        if ((res = ::write(_fd, &c, 1)) != 1) {
            return EOF;
        }
        else {
            std::cerr << "write result = " << res << ", errno = " << errno << '\n';
        }
    }
    return c;
}

std::streamsize sc::io::fdiobuf::xsputn(const char* s, std::streamsize num) {
    int res = ::write(_fd, s, num);
    if (res != num) {
        std::cerr << "write result = " << res << ", errno = " << errno << '\n';
        return EOF;
    }
    return res;
}