#!/bin/bash

# Copyright (C) 2009-2010 Stelios Stavroulakis <sstavra@gmail.com>
# sabaki

# sabaki is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published
# by the Free Software Foundation, either version 3 of the License,
# or (at your option) any later version.

# sabaki is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with sabaki. If not, see <http://www.gnu.org/licenses/>.

# run as root: ./sabaki bus:devnum [dir1 dir2 dir3 ...]
# dir1, dir2, dir3 should be the full paths to dir1, dir2, dir3
# to see the exit status, run as root: echo $?
VERSION="0.2"
TODAY=`date '+20%y%m%d'`
startdir=/root/taisabaki
tempdir=/tmp
setup_file=$startdir/sabaki_setup.txt
trg_min_limit=512
bkp_start_date=`date '+20%y%m%d %R'`
file=$startdir/sabaki_last.txt
bkp_msg_file=$startdir/sabaki_messages.txt
magic_file=$startdir/.magicnum
exclude_file=$startdir/exclude.txt
temp_file=$startdir/temp1
host=`hostname`

process=`ps -e | grep -c sabaki`
if [ "$process" -gt "2" ] ; then
  exit 1
fi

if [ ! -e $startdir ] ; then
  mkdir $startdir
fi

if [ ! -e $exclude_file ] ; then
  touch $exclude_file
fi

# read command line params
i=0
for WORD in "$@";
do
clp[$i]=$WORD
i=`expr $i + 1`
done
max=$i

if [ "$max" -eq "0" ] ; then
  echo "no arguments defined - backup interrupted" >> $bkp_msg_file
  exit 2
fi

if [ "${clp[0]}" == "--version" ] ; then
  echo "sabaki $VERSION"
  exit 0
fi

if [ "${clp[0]}" == "--print" ] ; then
  if [ -e $setup_file ] ; then
    cat $setup_file
  fi
  exit 0
fi

if [ "${clp[0]}" == "--add" ] ; then
  if [ "$max" -eq "2" ] ; then
    echo "${clp[1]}" >> $setup_file
  fi
  exit 0
fi

if [ "${clp[0]}" == "--magic" ] ; then
  if [ ! -e $magic_file ] ; then
    echo `< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c16` >> $magic_file
  else
    rm $magic_file
    echo `< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c16` >> $magic_file
  fi
  exit 0
fi

if [ "${clp[0]}" == "--msg" ] ; then
  if [ -e $bkp_msg_file ] ; then
    cat $bkp_msg_file
  fi
  exit 0
fi

if [ -e $temp_file ] ; then
  rm $temp_file
fi

if [ "${clp[0]}" == "--replace" ] ; then
  if [ "$max" -eq "2" ] ; then
    sed "s/${clp[1]}//g;/^$/d" $setup_file > $temp_file
    mv $temp_file $setup_file
  fi
  if [ "$max" -eq "3" ] ; then
    sed "s/${clp[1]}/${clp[2]}/g;/^$/d" $setup_file > $temp_file
    mv $temp_file $setup_file
  fi
  exit 0
fi

if [ -e $temp_file ] ; then
  rm $temp_file
fi

if [ -e $bkp_msg_file ] ; then
  rm $bkp_msg_file
fi

echo "start date : $bkp_start_date" >> $bkp_msg_file

# check last backup date
if [ -e $file ] ; then
  last_date=`cat $file | awk '{print $1}'`
  if [ "$last_date" == "$TODAY" ] ; then
    echo "configured to run in a host once a day - backup interrupted" >> $bkp_msg_file
    exit 3
  fi
fi

srcdir=/home
bkp_src_index=0
if [ "$max" -gt "1" ] ; then
  bkp_src_index=1
fi

# check that the usb bus:devnum contains the colon char
sub=`expr index "${clp[0]}" :` 
if [ "$sub" -eq "0" ] ; then
  echo "target is not defined - backup interrupted" >> $bkp_msg_file
  exit 4
else
# check if usb dev is connected
  TEMP=
  RES=`lsusb | grep ${clp[0]}`
  if [ "$RES" == "$TEMP" ] ; then
    echo "target is not connected - backup interrupted" >> $bkp_msg_file
    exit 5
  fi
  mountdir=/media
fi

# check that bus:devnum is within setup
if [ "${clp[0]}" != "" ] ; then
  dev_in_setup=`grep -c ${clp[0]} $setup_file`
  if [ "$dev_in_setup" -eq "0" ] ; then
    echo "bus:devnum not in setup - backup interrupted" >> $bkp_msg_file
    exit 6
  fi
fi

# find the mounted devices
lines=`/sbin/fdisk -l | awk '{print $1}' | grep dev | awk 'END{print NR}'`
for ((i=0;i<$lines;i+=1));
do
j=`expr $i + 1`
mdev[$i]=`/sbin/fdisk -l | awk '{print $1}' | grep dev | awk -v db=$j 'NR == db'`
done

# find the boot device
bdev=`/sbin/fdisk -l | grep \* | grep dev | awk '{print $1}'`

# use bdev to exclude all sda devices from mountpoint search for magicnum
# exclude from mount points the partitions that are similar to boot partition
len=`expr length $bdev`
if [ "$len" -gt "6" ] ; then
  len=`expr $len - 1`
  sub_bdev=${bdev:0:$len}
else
  echo "unusual source partitions - please check manually - backup interrupted" >> $bkp_msg_file
  exit 7
fi
j=0
for ((i=0;i<$lines;i+=1));
do
len=`expr length ${mdev[$i]} - 1`
sub_mdev=${mdev[$i]:0:$len}
if [ "$sub_mdev" != "$sub_bdev" ] ; then
  k=6
  maxm=10
  for ((m=0;m<$maxm;m+=1));
  do
  mpoint[$m]=`df | grep "$sub_mdev" | awk -v db=$k '{print $db}'`
  if [ "${mpoint[$m]}" == "" ] ; then
    break
  fi
  k=`expr $k + 1`
  done
  spaces=`expr $k - 6 - 1`
  if [ "$spaces" -gt "3" ] ; then
    echo "ridiculously many spaces in mount point - backup interrupted" >> $bkp_msg_file
    exit 8
  fi
  if [ "$spaces" -eq "0" ] ; then
    mount_point[$j]=`df | grep ${mdev[$i]} | awk '{ print $6 }'`
  fi
  if [ "$spaces" -eq "1" ] ; then
    mount_point[$j]=`df | grep ${mdev[$i]} | awk '{ print $6, $7 }'`
  fi
  if [ "$spaces" -eq "2" ] ; then
    mount_point[$j]=`df | grep ${mdev[$i]} | awk '{ print $6, $7, $8 }'`
  fi
  if [ "$spaces" -eq "3" ] ; then
    mount_point[$j]=`df | grep ${mdev[$i]} | awk '{ print $6, $7, $8, $9 }'`
  fi
  j=`expr $j + 1`
fi
done
mplen=$j

if [ ! -e $magic_file ] ; then
  echo "magic file is missing - backup interrupted" >> $bkp_msg_file
  exit 9
fi

# find the mount point corresponding to the target with the right magic number
j=0
num=0
count=0
flag=0
for ((i=0;i<$mplen;i+=1));
do
if [ -e "${mount_point[$i]}/.magicnum" ] ; then
  tmagic=`cat "${mount_point[$i]}/.magicnum" | awk '{print $1}'`
  if [ "$tmagic" != "" ] ; then
    mlen=`expr length $tmagic`
    if [ "$mlen" -ne "16" ] ; then
      echo "16 is the right length for the magic number - backup interrupted" >> $bkp_msg_file
      exit 10
    fi
    flag=1
    num=`grep -c $tmagic $magic_file`
    if [ "$num" -gt "0" ] ; then
      count=`expr $count + 1`
      mindex[$j]=$i
      j=`expr $j + 1`
    fi
  fi
fi
done
if [ "$flag" -eq "0" ] ; then
  echo "no magic number in mount points - backup interrupted" >> $bkp_msg_file
  exit 11
fi
if [ "$flag" -eq "1" ] ; then
  if [ "$count" -eq "0" ] ; then
    echo "no matching magic number in target - backup interrupted" >> $bkp_msg_file
    exit 12
  fi
fi
if [ "$count" -gt "1" ] ; then
  echo "identical magic numbers in mount points - backup interrupted" >> $bkp_msg_file
  exit 13
fi
selected_mount_point=${mount_point[${mindex[0]}]}
mp_host_file=$selected_mount_point/.sabaki_host
smpoint_len=`expr length "$selected_mount_point"`
if [ "$smpoint_len" -gt "32" ] ; then
  echo "mount point is too long - backup interrupted" >> $bkp_msg_file
  exit 14
fi
bkp_msg_file2=$selected_mount_point/sabaki_messages.txt

if [ ! -e "$mp_host_file" ] ; then
  echo "no host file in mount point - backup interrupted" >> $bkp_msg_file
  exit 15
else
  mphost=`cat "$mp_host_file" | awk '{print $1}'`
  if [ "$mphost" != "$host" ] ; then
    echo "no host in mount point - backup interrupted" >> $bkp_msg_file
    exit 16
  fi
fi

# compute backup source space usage
bkp_src_usage=0
if [ "$bkp_src_index" -eq "1" ] ; then
  for ((i=$bkp_src_index;i<$max;i+=1));
  do
  cap=`du -s "${clp[$i]}" 2>/dev/null | awk '{print $1}'`
  bkp_src_usage=$[$bkp_src_usage + $cap]
  done
else
  bkp_src_usage=`du -s $srcdir 2>/dev/null | awk '{print $1}'`
fi

# compute backup target capacity
bkp_trg_cap=`df "$selected_mount_point" | awk '{ field = $2 }; END { print field }'`
# compute backup target usage
bkp_trg_usage=`df "$selected_mount_point" | awk '{ field = $3 }; END { print field }'`
# compute backup target avail
bkp_trg_avail=`df "$selected_mount_point" | awk '{ field = $4 }; END { print field }'`

if [ "$bkp_src_usage" -ge "$bkp_trg_cap" ] ; then
  echo "insufficient target capacity - backup interrupted" >> $bkp_msg_file
  exit 17
fi

if [ -e "$bkp_msg_file2" ] ; then
  rm "$bkp_msg_file2"
fi
if [ -e $file ] ; then
  rm $file
fi
IFS=$'\n'

if [ ! -e "$selected_mount_point/$host" ] ; then
  mkdir "$selected_mount_point/$host"
fi

if [ "$bkp_src_index" -eq "1" ] ; then
  for ((i=$bkp_src_index;i<$max;i+=1));
  do
  rsync -rRupt --safe-links --whole-file --exclude-from=$exclude_file "${clp[$i]}" "$selected_mount_point/$host" 1>/dev/null 2>&1
  done
else
  rsync -rRupt --safe-links --whole-file --exclude-from=$exclude_file $srcdir "$selected_mount_point/$host" 1>/dev/null 2>&1
fi

bkp_trg_avail=`df "$selected_mount_point" | awk '{ field = $4 }; END { print field }'`
lim=`expr $bkp_trg_avail \* 100 / $bkp_trg_cap`
if [ "$lim" -eq "0" ] ; then
  echo "Warning: target almost full" >> $bkp_msg_file
fi

bkp_end_date=`date '+20%y%m%d %R'`
echo "end date   : $bkp_end_date" >> $bkp_msg_file
echo $bkp_end_date >> $file
cp $bkp_msg_file "$selected_mount_point"
exit 0