#!/bin/bash

SECTORS=$(parted ${1} unit s print | grep '^Disk /dev' | cut -d: -f2 | sed 's/ //g;s/s//g')
HDDSIZE=$((${SECTORS} * 512))
BLKSIZE=$((4 * 1024))
TBLOCKS=$((${HDDSIZE} / ${BLKSIZE}))

DESTROY=true
EXHAUST=12
echo Device ${1} is $(printf "%'d" ${HDDSIZE}) bytes
echo Testing $(printf "%'d" ${TBLOCKS}) blocks of $(printf "%'d\n" ${BLKSIZE}) bytes using 1/${EXHAUST} exhaustion.
POINTER=$((${RANDOM} % ${EXHAUST}))

BEGIN=$(date +%s)

until [ ${POINTER} = ${TBLOCKS} ]; do
#  RUNTIME=$(($(date +%s) - ${BEGIN}))
#  RTD=$((${RUNTIME} / 86400))
#  RTH=$((${RUNTIME} % 86400 / 3600))
#  RTM=$((${RUNTIME} % 3600 / 60))
#  RTS=$((${RUNTIME} % 60))

#  ETATIME=$(echo "scale=6;${RUNTIME}/(${POINTER}+1)*${TBLOCKS}+0.5" | bc | cut -d. -f1)
#  [[ -z ${ETATIME} ]] && ETATIME=0
#  ETD=$((${ETATIME} / 86400))
#  ETH=$((${ETATIME} % 86400 / 3600))
#  ETM=$((${ETATIME} % 3600 / 60))
#  ETS=$((${ETATIME} % 60))
  
#  ETRTIME=$((${ETATIME} - ${RUNTIME}))
#  ERD=$((${ETRTIME} / 86400))
#  ERH=$((${ETRTIME} % 86400 / 3600))
#  ERM=$((${ETRTIME} % 3600 / 60))
#  ERS=$((${ETRTIME} % 60))

#  echo -n RUN $(printf "%02d:%02d:%02d:%02d\n" ${RTD} ${RTH} ${RTM} ${RTS})' '
#  echo -n ETA $(printf "%02d:%02d:%02d:%02d\n" ${ETD} ${ETH} ${ETM} ${ETS})' '
#  echo -n ETR $(printf "%02d:%02d:%02d:%02d\n" ${ERD} ${ERH} ${ERM} ${ERS})' '

  echo -n BLK $(printf "%012d" ${POINTER} | sed 's/\(...\)\(...\)\(...\)\(...\)/\1,\2,\3,\4/g')...

  RNDDATA="$(dd if=/dev/urandom bs=${BLKSIZE} count=1 status=none | base64)"; echo -n G 
  ${DESTROY} || ( ORGDATA="$(dd if=${1} bs=${BLKSIZE} count=1 skip=${POINTER} status=none | base64)"; echo -n B )
  echo "${RNDDATA}" | base64 --decode | dd of=${1} bs=${BLKSIZE} seek=${POINTER} status=none; sync; echo -n W 
  CHKDATA=$(dd if=${1} bs=${BLKSIZE} count=1 skip=${POINTER} status=none| base64); echo -n V 
  ${DESTROY} || ( echo "${ORGDATA}" | base64 --decode | dd of=${1} bs=${BLKSIZE} seek=${POINTER} status=none; sync; echo -n R )
  [[ "${CHKDATA}" == "${RNDDATA}" ]] && echo -ne "\r" || echo "...FAILED"
  ((POINTER+=${EXHAUST}))
done