//  Copyright 2015 Google Inc. All Rights Reserved.
//
//  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.

#include "stdafx.h"

#ifndef _UNICODE
#define _UNICODE
#endif

#ifndef UNICODE
typedef std::string String;
#else
typedef std::wstring String;
#endif

bool CreateNativeHardlink(LPCWSTR linkname, LPCWSTR targetname)
{
	std::wstring full_linkname = BuildFullPath(linkname, true);
	size_t len = full_linkname.size() * sizeof(WCHAR);

	typed_buffer_ptr<FILE_LINK_INFORMATION> link_info(sizeof(FILE_LINK_INFORMATION) + len - sizeof(WCHAR));

	memcpy(&link_info->FileName[0], full_linkname.c_str(), len);
	link_info->ReplaceIfExists = TRUE;
	link_info->FileNameLength = len;

	std::wstring full_targetname = BuildFullPath(targetname, true);

	HANDLE hFile = OpenFileNative(full_targetname.c_str(), nullptr, MAXIMUM_ALLOWED, FILE_SHARE_READ, 0);
	if (hFile)
	{
		DEFINE_NTDLL(ZwSetInformationFile);
		IO_STATUS_BLOCK io_status = { 0 };

		NTSTATUS status = fZwSetInformationFile(hFile, &io_status, link_info, link_info.size(), FileLinkInformation);
		CloseHandle(hFile);
		if (NT_SUCCESS(status))
		{
			return true;
		}
		SetNtLastError(status);
	}

	return false;
}


int _tmain(int argc, _TCHAR* argv[])
{
	if (argc < 3)
	{
		printf("CreateHardLink hardlink target\n");
		printf("Example: hello.txt goodbye.txt\n");
		return 1;
	}
	else
	{
		if (CreateNativeHardlink(argv[1], argv[2]))
		{
			printf("Done\n");
		}
		else
		{
			printf("Error creating hardlink");
			return 1;
		}
	}

	return 0;
}