// backend\postwork_lock_windows.go

//go:build windows

package main

import (
	"os"
	"syscall"
)

const fileShareDelete = 0x00000004

func lockPostWorkFile(path string) (*os.File, error) {
	ptr, err := syscall.UTF16PtrFromString(path)
	if err != nil {
		return nil, err
	}

	handle, err := syscall.CreateFile(
		ptr,
		0, // desired access: nur Handle halten, kein Lesen/Schreiben nötig
		syscall.FILE_SHARE_READ|syscall.FILE_SHARE_WRITE, // bewusst OHNE FILE_SHARE_DELETE
		nil,
		syscall.OPEN_EXISTING,
		syscall.FILE_ATTRIBUTE_NORMAL,
		0,
	)
	if err != nil {
		return nil, err
	}

	return os.NewFile(uintptr(handle), path), nil
}