// Copyright 2021 The Go Authors. All rights reserved.

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

package unix

import (

	"runtime"

	"unsafe"

)

// IoctlRetInt performs an ioctl operation specified by req on a device

// associated with opened file descriptor fd, and returns a non-negative

// integer that is returned by the ioctl syscall.

func IoctlRetInt(fd int, req uint) (int, error) {

	ret, _, err := Syscall(SYS_IOCTL, uintptr(fd), uintptr(req), 0)

	if err != 0 {

		return 0, err

	}

	return int(ret), nil

}

func IoctlGetUint32(fd int, req uint) (uint32, error) {

	var value uint32

	err := ioctl(fd, req, uintptr(unsafe.Pointer(&value)))

	return value, err

}

func IoctlGetRTCTime(fd int) (*RTCTime, error) {

	var value RTCTime

	err := ioctl(fd, RTC_RD_TIME, uintptr(unsafe.Pointer(&value)))

	return &value, err

}

func IoctlSetRTCTime(fd int, value *RTCTime) error {

	err := ioctl(fd, RTC_SET_TIME, uintptr(unsafe.Pointer(value)))

	runtime.KeepAlive(value)

	return err

}

func IoctlGetRTCWkAlrm(fd int) (*RTCWkAlrm, error) {

	var value RTCWkAlrm

	err := ioctl(fd, RTC_WKALM_RD, uintptr(unsafe.Pointer(&value)))

	return &value, err

}

func IoctlSetRTCWkAlrm(fd int, value *RTCWkAlrm) error {

	err := ioctl(fd, RTC_WKALM_SET, uintptr(unsafe.Pointer(value)))

	runtime.KeepAlive(value)

	return err

}

type ifreqEthtool struct {

	name [IFNAMSIZ]byte

	data unsafe.Pointer

}

// IoctlGetEthtoolDrvinfo fetches ethtool driver information for the network

// device specified by ifname.

func IoctlGetEthtoolDrvinfo(fd int, ifname string) (*EthtoolDrvinfo, error) {

	// Leave room for terminating NULL byte.

	if len(ifname) >= IFNAMSIZ {

		return nil, EINVAL

	}

	value := EthtoolDrvinfo{

		Cmd: ETHTOOL_GDRVINFO,

	}

	ifreq := ifreqEthtool{

		data: unsafe.Pointer(&value),

	}

	copy(ifreq.name[:], ifname)

	err := ioctl(fd, SIOCETHTOOL, uintptr(unsafe.Pointer(&ifreq)))

	runtime.KeepAlive(ifreq)

	return &value, err

}

// IoctlGetWatchdogInfo fetches information about a watchdog device from the

// Linux watchdog API. For more information, see:

// https://www.kernel.org/doc/html/latest/watchdog/watchdog-api.html.

func IoctlGetWatchdogInfo(fd int) (*WatchdogInfo, error) {

	var value WatchdogInfo

	err := ioctl(fd, WDIOC_GETSUPPORT, uintptr(unsafe.Pointer(&value)))

	return &value, err

}

// IoctlWatchdogKeepalive issues a keepalive ioctl to a watchdog device. For

// more information, see:

// https://www.kernel.org/doc/html/latest/watchdog/watchdog-api.html.

func IoctlWatchdogKeepalive(fd int) error {

	return ioctl(fd, WDIOC_KEEPALIVE, 0)

}

// IoctlFileCloneRange performs an FICLONERANGE ioctl operation to clone the

// range of data conveyed in value to the file associated with the file

// descriptor destFd. See the ioctl_ficlonerange(2) man page for details.

func IoctlFileCloneRange(destFd int, value *FileCloneRange) error {

	err := ioctl(destFd, FICLONERANGE, uintptr(unsafe.Pointer(value)))

	runtime.KeepAlive(value)

	return err

}

// IoctlFileClone performs an FICLONE ioctl operation to clone the entire file

// associated with the file description srcFd to the file associated with the

// file descriptor destFd. See the ioctl_ficlone(2) man page for details.

func IoctlFileClone(destFd, srcFd int) error {

	return ioctl(destFd, FICLONE, uintptr(srcFd))

}

type FileDedupeRange struct {

	Src_offset uint64

	Src_length uint64

	Reserved1  uint16

	Reserved2  uint32

	Info       []FileDedupeRangeInfo

}

type FileDedupeRangeInfo struct {

	Dest_fd       int64

	Dest_offset   uint64

	Bytes_deduped uint64

	Status        int32

	Reserved      uint32

}

// IoctlFileDedupeRange performs an FIDEDUPERANGE ioctl operation to share the

// range of data conveyed in value from the file associated with the file

// descriptor srcFd to the value.Info destinations. See the

// ioctl_fideduperange(2) man page for details.

func IoctlFileDedupeRange(srcFd int, value *FileDedupeRange) error {

	buf := make([]byte, SizeofRawFileDedupeRange+

		len(value.Info)*SizeofRawFileDedupeRangeInfo)

	rawrange := (*RawFileDedupeRange)(unsafe.Pointer(&buf[0]))

	rawrange.Src_offset = value.Src_offset

	rawrange.Src_length = value.Src_length

	rawrange.Dest_count = uint16(len(value.Info))

	rawrange.Reserved1 = value.Reserved1

	rawrange.Reserved2 = value.Reserved2

	for i := range value.Info {

		rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(

			uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +

				uintptr(i*SizeofRawFileDedupeRangeInfo)))

		rawinfo.Dest_fd = value.Info[i].Dest_fd

		rawinfo.Dest_offset = value.Info[i].Dest_offset

		rawinfo.Bytes_deduped = value.Info[i].Bytes_deduped

		rawinfo.Status = value.Info[i].Status

		rawinfo.Reserved = value.Info[i].Reserved

	}

	err := ioctl(srcFd, FIDEDUPERANGE, uintptr(unsafe.Pointer(&buf[0])))

	// Output

	for i := range value.Info {

		rawinfo := (*RawFileDedupeRangeInfo)(unsafe.Pointer(

			uintptr(unsafe.Pointer(&buf[0])) + uintptr(SizeofRawFileDedupeRange) +

				uintptr(i*SizeofRawFileDedupeRangeInfo)))

		value.Info[i].Dest_fd = rawinfo.Dest_fd

		value.Info[i].Dest_offset = rawinfo.Dest_offset

		value.Info[i].Bytes_deduped = rawinfo.Bytes_deduped

		value.Info[i].Status = rawinfo.Status

		value.Info[i].Reserved = rawinfo.Reserved

	}

	return err

}

func IoctlHIDGetDesc(fd int, value *HIDRawReportDescriptor) error {

	err := ioctl(fd, HIDIOCGRDESC, uintptr(unsafe.Pointer(value)))

	runtime.KeepAlive(value)

	return err

}

func IoctlHIDGetRawInfo(fd int) (*HIDRawDevInfo, error) {

	var value HIDRawDevInfo

	err := ioctl(fd, HIDIOCGRAWINFO, uintptr(unsafe.Pointer(&value)))

	return &value, err

}

func IoctlHIDGetRawName(fd int) (string, error) {

	var value [_HIDIOCGRAWNAME_LEN]byte

	err := ioctl(fd, _HIDIOCGRAWNAME, uintptr(unsafe.Pointer(&value[0])))

	return ByteSliceToString(value[:]), err

}

func IoctlHIDGetRawPhys(fd int) (string, error) {

	var value [_HIDIOCGRAWPHYS_LEN]byte

	err := ioctl(fd, _HIDIOCGRAWPHYS, uintptr(unsafe.Pointer(&value[0])))

	return ByteSliceToString(value[:]), err

}

func IoctlHIDGetRawUniq(fd int) (string, error) {

	var value [_HIDIOCGRAWUNIQ_LEN]byte

	err := ioctl(fd, _HIDIOCGRAWUNIQ, uintptr(unsafe.Pointer(&value[0])))

	return ByteSliceToString(value[:]), err

}