// Copyright 2020 Douyu
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// +build windows
package xfile

import (
	"io"
	"syscall"
)

// lockCloser hides all of an syscall.Handle's methods, except for Close.
type lockCloser struct {
	fd syscall.Handle
}

// Close ...
func (l lockCloser) Close() error {
	return syscall.Close(l.fd)
}

// Lock ...
func Lock(name string) (io.Closer, error) {
	p, err := syscall.UTF16PtrFromString(name)
	if err != nil {
		return nil, err
	}
	fd, err := syscall.CreateFile(p,
		syscall.GENERIC_READ|syscall.GENERIC_WRITE,
		0, nil, syscall.CREATE_ALWAYS,
		syscall.FILE_ATTRIBUTE_NORMAL,
		0,
	)
	if err != nil {
		return nil, err
	}
	return lockCloser{fd: fd}, nil
}
