/**
 * @file    shred.h
 * @brief   shred drive
 * @author  hendrik schutter
 * @date    03.05.2020
 */

#ifndef SHRED_H_
#define SHRED_H_

#include "reHDD.h"

#include <iostream>
#include <fstream>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>

#define CHUNK_SIZE 1024*1024*2 //amount of bytes that are overwritten at once --> 2MB
#define CHUNK_DIMENSION 100U //amount of chunks are read at once from random source

//#define DEMO_DRIVE_SIZE 1024*1024*256L // 256MB
//#define DEMO_DRIVE_SIZE 1024*1024*1024L // 1GB
//#define DEMO_DRIVE_SIZE 1024*1024*1024*10L // 10GB

typedef int fileDescriptor;

class Shred
{
protected:

public:

    Shred();
    ~Shred();
    int shredDrive(Drive* drive, int* ipSignalFd);

private:
    fileDescriptor randomSrcFileDiscr;
    fileDescriptor driveFileDiscr;
    unsigned char caChunk[CHUNK_DIMENSION][CHUNK_SIZE];
    unsigned long ulDriveByteSize;
    unsigned long ulDriveByteOverallCount = 0; //all bytes shredded in all iterations + checking -> used for progress calculation
    double d32Percent = 0.0;
    double d32TmpPercent = 0.0;

    inline double calcProgress();
    int iRewindDrive(fileDescriptor file);
    unsigned long getDriveSizeInBytes(fileDescriptor file);
    unsigned int uiCalcChecksum(fileDescriptor file, Drive* drive, int* ipSignalFd);
    void cleanup();

};

#endif  // SHRED_H_