#!/usr/bin/env bash



  #
  # Copyright (C) 2010 Cloud.com, Inc.  All rights reserved.
  # 
  # This software is licensed under the GNU General Public License v3 or later.
  # 
  # It 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 any later version.
  # This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
  #
 

# $Id: managesnapshot.sh 11601 2010-08-11 17:26:15Z kris $ $HeadURL: svn://svn.lab.vmops.com/repos/branches/2.1.refactor/java/scripts/storage/qcow2/managesnapshot.sh $
# managesnapshot.sh -- manage snapshots for a single disk (create, destroy, rollback)
#

usage() {
  printf "Usage: %s: -c <path to disk> -n <snapshot name>\n" $(basename $0) >&2
  printf "Usage: %s: -d <path to disk> -n <snapshot name>\n" $(basename $0) >&2
  printf "Usage: %s: -r <path to disk> -n <snapshot name>\n" $(basename $0) >&2
  printf "Usage: %s: -b <path to disk> -n <snapshot name> -p <dest name>\n" $(basename $0) >&2
  exit 2
}

qemu_img="cloud-qemu-img"
which $qemu_img
if [ $? -gt 0 ]
then
   which qemu-img
   if [ $? -eq 0 ]
   then
       qemu_img="qemu-img"
   fi
fi

create_snapshot() {
  local disk=$1
  local snapshotname=$2
  local failed=0

  if [ ! -f $disk ]
  then
     failed=1
     printf "No disk $disk exist\n" >&2
     return $failed
  fi

  $qemu_img snapshot -c $snapshotname $disk
  
  if [ $? -gt 0 ]
  then
    failed=2
    printf "***Failed to create snapshot $snapshotname for path $disk\n" >&2
    $qemu_img snapshot -d $snapshotname $disk
    
    if [ $? -gt 0 ]
    then
      printf "***Failed to delete snapshot $snapshotname for path $disk\n" >&2
    fi
  fi

  return $failed 
}

destroy_snapshot() {
  local disk=$1
  local snapshotname=$2
  local failed=0

  if [ -d $disk ]
  then
     if [ -f $disk/$snapshotname ]
     then
	    rm -rf $disk/$snapshotname >& /dev/null
     fi

     return $failed
  fi

  if [ ! -f $disk ]
  then
     failed=1
     printf "No disk $disk exist\n" >&2
     return $failed
  fi

  $qemu_img snapshot -d $snapshotname $disk
  if [ $? -gt 0 ]
  then
     failed=2
     printf "Failed to delete snapshot $snapshotname for path $disk\n" >&2
  fi	

  return $failed 
}

rollback_snapshot() {
  local disk=$1
  local snapshotname=$2
  local failed=0

  $qemu_img snapshot -a $snapshotname $disk
  
  if [ $? -gt 0 ]
  then
    printf "***Failed to apply snapshot $snapshotname for path $disk\n" >&2
    failed=1
  fi
  
  return $failed 
}
backup_snapshot() {
  local disk=$1
  local snapshotname=$2
  local destPath=$3
  local destName=$4

  if [ ! -d $destPath ]
  then
     mkdir -p $destPath >& /dev/null
     if [ $? -gt 0 ]
     then
        printf "Failed to create $destPath" >&2
        return 3
     fi
  fi

  # Does the snapshot exist? 
  $qemu_img snapshot -l $disk|grep -w "$snapshotname" >& /dev/null
  if [ $? -gt 0 ]
  then
    printf "there is no $snapshotname on disk $disk" >&2
    return 1
  fi

  $qemu_img convert -f qcow2 -O qcow2 -s $snapshotname $disk $destPath/$destName >& /dev/null
  if [ $? -gt 0 ]
  then
    printf "Failed to backup $snapshotname for disk $disk to $destPath" >&2
    return 2
  fi
  return 0
}
#set -x

cflag=
dflag=
rflag=
bflag=
nflag=
pathval=
snapshot=
tmplName=
deleteDir=

while getopts 'c:d:r:n:b:p:t:f' OPTION
do
  case $OPTION in
  c)	cflag=1
	pathval="$OPTARG"
	;;
  d)    dflag=1
        pathval="$OPTARG"
        ;;
  r)    rflag=1
        pathval="$OPTARG"
        ;;
  b)    bflag=1
        pathval="$OPTARG"
        ;;
  n)	nflag=1
	snapshot="$OPTARG"
	;;
  p)    destPath="$OPTARG"
        ;;
  t)    tmplName="$OPTARG"
	;;
  f)    deleteDir=1
	;;
  ?)	usage
	;;
  esac
done


if [ "$cflag" == "1" ]
then
  create_snapshot $pathval $snapshot
  exit $?
elif [ "$dflag" == "1" ]
then
  destroy_snapshot $pathval $snapshot $deleteDir
  exit $?
elif [ "$bflag" == "1" ]
then
  backup_snapshot $pathval $snapshot $destPath $tmplName
  exit $?
elif [ "$rflag" == "1" ]
then
  rollback_snapshot $pathval $snapshot $destPath
  exit $?
fi


exit 0