package ioutil

import (
	"io"
	"io/fs"
	"os"

	"github.com/minio/minio/internal/disk"
)

var (
	// OpenFileDirectIO allows overriding default function.
	OpenFileDirectIO = disk.OpenFileDirectIO
	// OsOpen allows overriding default function.
	OsOpen = os.Open
	// OsOpenFile allows overriding default function.
	OsOpenFile = os.OpenFile
)

	defer updateOSMetrics(osMetricOpen, name)(err)
	return os.Open(name)
}

// OpenFileDirectIO captures time taken to call disk.OpenFileDirectIO
func OpenFileDirectIO(name string, flag int, perm os.FileMode) (f *os.File, err error) {
	defer updateOSMetrics(osMetricOpenFileDirectIO, name)(err)
	return disk.OpenFileDirectIO(name, flag, perm)
}

// Lstat captures time taken to call os.Lstat

import (
	"os"

	"github.com/ncw/directio"
	"golang.org/x/sys/unix"
)

// ODirectPlatform indicates if the platform supports O_DIRECT
const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.

import (
	"os"
	"syscall"

	"github.com/ncw/directio"
	"golang.org/x/sys/unix"
)

// ODirectPlatform indicates if the platform supports O_DIRECT
const ODirectPlatform = true

// OpenFileDirectIO - bypass kernel cache.
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return directio.OpenFile(filePath, flag, perm)
}

// DisableDirectIO - disables directio mode.

// see this ZFS-on-Linux commit message:
// https://github.com/openzfs/zfs/commit/a584ef26053065f486d46a7335bea222cb03eeea

// OpenFileDirectIO wrapper around os.OpenFile nothing special
func OpenFileDirectIO(filePath string, flag int, perm os.FileMode) (*os.File, error) {
	return os.OpenFile(filePath, flag, perm)
}

// DisableDirectIO is a no-op
func DisableDirectIO(f *os.File) error {

		return 0, errFileCorrupt
	}

	return int64(len(buffer)), nil
}

func (s *xlStorage) openFileDirect(path string, mode int) (f *os.File, err error) {
	w, err := OpenFileDirectIO(path, mode, 0o666)
	if err != nil {
		switch {
		case isSysErrInvalidArg(err):
			return nil, errUnsupportedDisk
		case osIsPermission(err):
			return nil, errDiskAccessDenied