package fileutil

import (
	"os"

	"golang.org/x/sys/windows"
)

// AvailableBytes returns disk space available to the current user.
func AvailableBytes(dir string) (uint64, error) {
	name, err := windows.UTF16PtrFromString(dir)
	if err != nil {
		return 0, err
	}
	var available uint64
	err = windows.GetDiskFreeSpaceEx(name, &available, nil, nil)
	if err != nil {
		return 0, &os.PathError{Op: "GetDiskFreeSpaceEx", Path: dir, Err: err}
	}
	return available, nil
}