// +build windows

/*
** Zabbix
** Copyright (C) 2001-2021 Zabbix SIA
**
** 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 2 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, write to the Free Software
** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
**/

package win32

import (
	"syscall"
	"unsafe"

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

var (
	hAdvapi32 Hlib

	getServiceKeyName uintptr
)

func init() {
	hAdvapi32 = mustLoadLibrary("advapi32.dll")

	getServiceKeyName = hAdvapi32.mustGetProcAddress("GetServiceKeyNameW")
}

func GetServiceKeyName(h syscall.Handle, displayName string) (name string, err error) {
	wdn, err := windows.UTF16FromString(displayName)
	if err != nil {
		return
	}
	b := make([]uint16, 4096)
	size := uint32(len(b))
	ret, _, syserr := syscall.Syscall6(getServiceKeyName, 4, uintptr(h), uintptr(unsafe.Pointer(&wdn[0])),
		uintptr(unsafe.Pointer(&b[0])), uintptr(unsafe.Pointer(&size)), 0, 0)
	if ret == 0 {
		return "", syserr
	}
	return windows.UTF16ToString(b), nil
}
