#!/bin/sh

# Written by:  Brenda Bell
# Version:     1.1
# Date:        05 Oct 2003
# URL:         opensource.theotherbell.com

#
# This script is distributed as is without warrenty.
#
# It may be freely distributed with or without modification provided
# that:
#
# 1.  This header is included in the distribution
# 2.  The redistributor documents his modifications immediately 
#     below this header by providing his/her name and a description
#     of the modifications
#

# Change log:
#
# 05 Oct 2003: Added touch for excludefile to force its inclusion in
#              level 1 and level 2 backups
#

backup2disk_log() {

logger -s -p local0.info -t backup2disk "${1}"
echo ${1}
return 0

}

backup2disk_checkargs() {

# make sure every option has a value
if [ -z "$archivedir" ] || 
      [ -z "$backupdatadir" ] || 
      [ -z "$crossfilesystems" ] || 
      [ -z "$dereferencelinks" ] || 
      [ -z "$excludefile" ] || 
      [ -z "$level" ] || 
      [ -z "$disablecompression" ] || 
      [ -z "$notification" ] || 
      [ -z "$disableverify" ] || 
      [ -z "$sourcedir" ] ; then
    $me $* --help
    return 1
fi

# check options against allowed values
if [ "$crossfilesystems" != "yes" -a "$crossfilesystems" != "no" ] ||
    [ "$dereferencelinks" != "yes" -a "$dereferencelinks" != "no" ] ||
    [ "$level" != "0" -a "$level" != "1" -a "$level" != "2" ] ||
    [ "$disablecompression" != "yes" -a "$disablecompression" != "no" ] ||
    [ "$notification" != "none" -a "$notification" != "summary" -a "$notification" != "list" -a "$notification" != "verboselist" ] ||
    [ "$disableverify" != "yes" -a "$disableverify" != "no" ] ; then
  $me --help
  return 1
fi

if [ "$notification" = "summary" -o "$notification" = "list" -o "$notification" = "verboselist" ] ; then
  if [ -z "$sendto" ] ; then
    $me --help
    return 1
  fi
fi

# check for existence and appropriate permissions on files and directories
if [ ! -d $backupdatadir ] || [ ! -w $backupdatadir ] ; then
  echo $backupdatadir must exist for write
  return 1
fi

if [ "$excludefile" != "default" -a "$excludefile" != "none" ] ; then
  if [ ! -f $excludefile -o ! -r $excludefile ] ; then
    echo $excludefile must exist for read
    return 1
  fi
fi

if [ ! -d $sourcedir ] || [ ! -r $sourcedir ] ; then
  echo $sourcedir must exist for read
  return 1
fi

# mount filesystem
if [ "$mount" != "" ] ; then
  $mount
  if [ $? -ne 0 ] ; then
    backup2disk_log "$mount failed!"
    return 1
  fi
fi

if [ ! -d $archivedir ] || [ ! -w $archivedir ] ; then
  backup2disk_log "$archivedir must exist for write"
  return 1
fi

# make sure the archive directory exists
mkdir -p $archivedir/$sourcedir

# configure the environment for this backup session
echo "Starting backup configuration at `date`"

# set up date-based controls
now=`date`
datestamp=`date --date "$now" +%s`
sourceid=`echo $sourcedir | tr "/" "~"`
datestamp0=$backupdatadir/level0-$sourceid-datestamp
datestamp1=$backupdatadir/level1-$sourceid-datestamp
if [ "$level" -eq 0 ] ; then
  if [ -f $datestamp0 -a ! -w $datestamp0 ] ; then
    echo $datestamp0 not writable
    return 1
  fi
fi

if [ "$level" -eq 1 ] ; then
  if [ ! -f $datestamp0 -o ! -r $datestamp0 ] ; then
    echo $datestamp0 must exist for read
    return 1
  fi
  if [ -f $datestamp1 -a ! -w $datestamp1 ] ; then
    echo $datestamp1 not writable
    return 1
  fi
fi

if [ "$level" -eq 2 ] ; then
  if [ ! -f $datestamp1 -o ! -r $datestamp1 ] ; then
    echo $datestamp1 must exist for read
    return 1
  fi
fi

# set up tar options


if [ "$level" -eq 0 ] ; then
  lbltext="Level $level backup of $sourcedir as of $now"
elif [ "$level" -eq 1 ] ; then
  afterdate="--after-date '`cat $datestamp0`'"
  lbltext="Level $level backup of $sourcedir from `cat $datestamp0` to $now"
elif [ "$level" -eq 2 ] ; then
  afterdate="--after-date '`cat $datestamp1`'"
  lbltext="Level $level backup of $sourcedir from `cat $datestamp1` to $now"
fi
lbltext=`echo "$lbltext" | cut -c1-99`
label="--label '$lbltext'"

if [ "$excludefile" = "default" ] ; then
  excludefile="$backupdatadir/exclude-default"
fi

if [ "$excludefile" = "none" ] ; then
  sourcefiles="$sourcedir"
else
  if [ ! -f $excludefile -o ! -w $excludefile ] ; then
    echo "$excludefile must exist for read"
    return 1
  fi
  excludefrom="--exclude-from '$excludefile'"
  touch $excludefile
  sourcefiles="$excludefile $sourcedir"
fi

if [ "$disablecompression" != "yes" ] ; then
  gzip="--gzip"
  archiveextension="tgz"
else
  archiveextension="tar"
fi

archivefile="$archivedir/$sourcedir/$datestamp.$level.$archiveextension"
file="--file '$archivefile'"

if [ -f "$archivefile" ] ; then
  echo "$archivefile exists"
  return 1
fi

logger -s -p local0.info -t backup2disk "Preparing to archive ${sourcedir} to ${archivefile}"

if [ "$crossfilesystems" != "yes" ] ; then
  onefilesystem="--one-file-system"
fi

if [ "$disableverify" != "yes" ] ; then
  verbose="--verbose"
fi

logger -s -p local1.info -t backup2disk archivedir=$archivedir/$sourcedir
logger -s -p local1.info -t backup2disk backupdatadir=$backupdatadir
logger -s -p local1.info -t backup2disk crossfilesystems=$crossfilesystems
logger -s -p local1.info -t backup2disk dereferencelinks=$dereferencelinks
logger -s -p local1.info -t backup2disk disablecompression=$disablecompression
logger -s -p local1.info -t backup2disk disableverify=$disableverify
logger -s -p local1.info -t backup2disk excludefile=$excludefile
logger -s -p local1.info -t backup2disk level=$level
logger -s -p local1.info -t backup2disk notification=$notification
logger -s -p local1.info -t backup2disk sendto=$sendto
logger -s -p local1.info -t backup2disk sourcedir=$sourcedir

return 0

}

backup2disk_notify() {

if [ "$notification" = "list" ] ; then
  notifycmd="eval tar --list $file $gzip"
elif [ "$notification" = "verboselist" ] ; then
  notifycmd="eval tar --list $file $gzip $verbose"
fi

if [ "$notification" != "none" ] ; then
  mail -s "$lbltext" $sendto <<EOF
${1}
`$notifycmd`
EOF
  backup2disk_log "Notification sent to $sendto"
fi

}