#include<stdio.h>
#include<stdlib.h>
#include<Windows.h>

#define BUFFER_LENGTH 12


int TransformA(HANDLE HandleFile)
{
	DWORD dwReadSize = 0;
	DWORD dwWriteSize = 0;
	DWORD dwFileSize = 0;
	BYTE *buffer = NULL;
	BOOL isWrite = FALSE;
	DWORD fileNormalIndex = 0;
	DWORD Index1 = 0;
	DWORD Index2 = 0;


	buffer = (BYTE*)malloc(BUFFER_LENGTH * sizeof(BYTE));
	DWORD bufferToReadSize = BUFFER_LENGTH;

	if (NULL == buffer)
	{
		printf("error:%d\n", GetLastError());
		return -1;
	}

	dwFileSize = SetFilePointer(HandleFile, 0, NULL, FILE_END);
	SetFilePointer(HandleFile, 0, NULL, FILE_BEGIN);


	//copy text
	while (ReadFile(HandleFile, buffer, bufferToReadSize, &dwReadSize, NULL) && dwReadSize > 0)
	{
		fileNormalIndex = SetFilePointer(HandleFile, 0, NULL, FILE_CURRENT);
		SetFilePointer(HandleFile, 0, NULL, FILE_END);

		if (fileNormalIndex + BUFFER_LENGTH > dwFileSize)
		{
			bufferToReadSize = dwFileSize - fileNormalIndex;
		}
		if (fileNormalIndex > dwFileSize)
		{
			break;
		}

		if (!WriteFile(HandleFile, buffer, dwReadSize, &dwWriteSize, NULL))
		{
			printf("error write: %d! \n", GetLastError());
		}
		fileNormalIndex = SetFilePointer(HandleFile, fileNormalIndex, NULL, FILE_BEGIN);
	}

	fileNormalIndex = SetFilePointer(HandleFile, dwFileSize, NULL, FILE_BEGIN);

	while (ReadFile(HandleFile, buffer, BUFFER_LENGTH, &dwReadSize, NULL) && dwReadSize > 0)
	{
		fileNormalIndex += dwReadSize;
		for (DWORD i = 1; i < dwReadSize; i++)
		{
			if (buffer[i] == ' ' || buffer[i] == 10 || buffer[i] == 13)
			{
				Index1 = i - 1;
			}
		}



		SetFilePointer(HandleFile, fileNormalIndex, NULL, FILE_BEGIN);
	}



	return 0;
}


int main(int argc, char**argv)
{
	HANDLE handleFile = INVALID_HANDLE_VALUE;
	char *fileName = argv[1];


	handleFile = CreateFileA(
		fileName,
		GENERIC_READ | GENERIC_WRITE,
		0,
		NULL,
		OPEN_EXISTING,
		FILE_ATTRIBUTE_NORMAL,
		NULL
	);



	if (INVALID_HANDLE_VALUE == handleFile)
	{
		printf("error:%d\n", GetLastError());
	}


	if (-1 == TransformA(handleFile))
	{
		printf("error transform\n");
	}


	system("pause");
	return 0;
}