#!/bin/bash

######################################################################################
# The goal of this script is to permit to do backups, restaurations, to list and     #
# delete the backups. The script facilitates the use of the repozo.py script given   #
# with Zope.                                                                         #
# Author: Francois Birot                                                             #
######################################################################################

#######################################################################################
#                                  INFORMATION                                        #
#######################################################################################
PYTHON_BIN="/zope/bin/python"
PYTHON_DIRECTORY="/zope/lib/python"
REPOZO_SCRIPT="/zope/bin/repozo.py"
ZOPE_DATABASE="/zope/production/server/var/Data.fs"
PRODUCTS_DIRECTORY="/zope/production/server/Products"
BACKUP_DIRECTORY="/zope/backups"
ZOPE_USER="zope"
UTC=-4 # The local time is UTC -04:00

#######################################################################################
#                                DEFAULT OPTIONS                                      #
#######################################################################################
VERBOSE="false" # Don't display anything
MOVE_CURRENT_DATAFS="false" # Don't backup the current Data.fs before restoring

#######################################################################################
#  This function checks if the verbose mode is activated and prints the first         #
#  parameter given to the function                                                    #
#######################################################################################
function print_message()
{
	if [[ $VERBOSE == "yes" ]]; then
                echo "--> $1"
        fi
}

#######################################################################################
# This function maintains a list of parameters to give to the repozo.py script        #
#######################################################################################
function add_option()
{
	if [[ -z "$OPTIONS" ]]; then
		OPTIONS="-$1"
	else
		OPTIONS=$OPTIONS" -$1"
	fi
}


#######################################################################################
# This function permits to delete a backup. It requires the basename of the backup as #
# the first parameter                                                                 #
#######################################################################################
function delete_backup()
{
	# If the backup exists, remove it
	if [[ -f $BACKUP_DIRECTORY/$1 ]]; then
		print_message "Removing $BACKUP_DIRECTORY/$1"
		rm $BACKUP_DIRECTORY/$1

		# If $1 equals "filename.ext", dat_file will be equals to "filename.dat"
		dat_file=${1/${1##*.}/dat}

		# If the dat file corresponding to the backup exists, remove it
		if [[ -f $BACKUP_DIRECTORY/$dat_file ]]; then
			print_message "Removing $BACKUP_DIRECTORY/$dat_file"
            rm $BACKUP_DIRECTORY/$dat_file	
		fi
	else
		print_message "The backup $1 doesn't exist"
	fi
}

#######################################################################################
# This function permit to display a size of a file in GB, MB, KB or B depending of it #
# The function requires one argument: the size to format and display                  #
#######################################################################################
function echo_size()
{
	SCALE=2 # Number of figures after the point

	if [[ $1 -gt $((1024*1024*1024)) ]]; then # If the size is greater than a GigaByte
		SIZE_UNIT="GB"
		SIZE=`echo "scale=$SCALE; $1/$((1024*1024*1024))" | bc -l`
	elif [[ $1 -gt $((1024*1024)) ]]; then # If the size is greater than a MegaByte
		SIZE_UNIT="MB"
		SIZE=`echo "scale=$SCALE; $1/$((1024*1024))" | bc -l`
	elif [[ $1 -gt $((1024)) ]]; then # If the size is greater than a KiloByte
		SIZE_UNIT="KB"
		SIZE=`echo "scale=$SCALE; $1/$((1024))" | bc -l`
	else # If the size is lower than a KiloByte
		SIZE_UNIT="B"
	fi

	echo -n $SIZE $SIZE_UNIT

}
#######################################################################################
# This function permits to display the date parsing the name of the backup            #
#######################################################################################
function echo_date_from_name()
{
	tab[1]="Jan"
	tab[2]="Feb"
	tab[3]="Mar"
	tab[4]="Apr"
	tab[5]="May"
	tab[6]="Jun"
	tab[7]="Jul"
	tab[8]="Aug"
	tab[9]="Sep"
	tab[10]="Oct"
	tab[11]="Nov"
	tab[12]="Dec"
	
	YEAR=`echo $1 | cut -d '-' -f 1`	
	MONTH=`echo $1 | cut -d '-' -f 2`	
	DAY=`echo $1 | cut -d '-' -f 3`
	HOUR=`echo $1 | cut -d '-' -f 4`	
	HOUR=$(((24+HOUR+UTC)%24))
	MIN=`echo $1 | cut -d '-' -f 5`	
	echo -n ${tab[$MONTH]} $DAY $YEAR $HOUR:$MIN
}

#######################################################################################
# This functions lists the backups found in $BACKUP_DIRECTORY                         #
#######################################################################################
function list_backups()
{
	i=1
	for DATABASE_FILE in `find $BACKUP_DIRECTORY -name "*.fs" -o -name "*.fsz" -o -name "*.deltafs" -o -name "*.deltafsz" | sort -rM`; do
		SIZE=$(stat -c "%s" $DATABASE_FILE)
		NAME=`basename $DATABASE_FILE`
		echo -ne "\t$i) "
		echo_date_from_name $NAME
		echo -n " "
		echo_size $SIZE
		echo -n " ($NAME : "
		if [[ ${NAME##*.} == "deltafs" || ${NAME##*.} == "deltafsz" ]]; then
			echo "INCREMENTAL)"
		else
			echo "FULL)"
		fi
		((i++))
	done
}

#######################################################################################
# This function displays some help about how to use the backup script                 #
#######################################################################################
function echo_help()
{
        echo ""
        echo -e "\t***Zope Backup Script***"
        echo ""
        echo -e "\tParameters:"
        echo -e "\t[-h] \tDisplays this help"
        echo -e "\t[-F] \tDoes a full backup"
        echo -e "\t[-I] \tDoes an incremental backup if an old backup is found, else it does a full backup."
	echo -e "\t[-D <backup filename>] \tDelete a specific backup file (Don't give the path, only the filename)"
        echo -e "\t[-R <backup filename>] \tRestores a specific backup file (Don't give the path, only the filename)"
	echo -e "\t[-m] \tBackup the current Data.fs before restoring (the parameter -R has to be specified)"
        echo -e "\t[-l] \tLists the backup files"
        echo -e "\t[-z] \tCompress with gzip the backup files"
        echo -e "\t[-v] \tVerbose mode"
}


#######################################################################################
#                                BEGINING OF THE SCRIPT                               #
#######################################################################################

# The repozo.py needs the PYTHONPATH environment variable to be set
export PYTHONPATH=$PYTHON_DIRECTORY

# The action variable can be changed depending of the parameters, to "backup", "suppression" or "restoration"
ACTION="nothing"

while getopts ":hlvzmFIR:D:" PARAM; do
case $PARAM in
h)
	echo_help
	exit 0
;;
l)
	list_backups
	exit 0
;;
F)
	ACTION="backup"
	INCREMENTAL_BACKUP="false"
;;
I)
	ACTION="backup"
	INCREMENTAL_BACKUP="true"
;;	
R)
	ACTION="restauration"
	BACKUP_FILE=$OPTARG
;;
D)
	ACTION="suppression"
	BACKUP_FILE=$OPTARG
;;
m)
	MOVE_CURRENT_DATAFS="yes"
;;
v)
	VERBOSE="yes"
	add_option "v"
;;
z)
	add_option "z"
;;
*)
	echo "Try '$0 -h' to get help"
	exit 1
;;
esac
done && shift $(($OPTIND - 1))

if [[ $ACTION == "nothing" ]]; then
	echo_help
	exit 1
fi

if [[ $ACTION == "backup" ]]; then

	if [[ -z $INCREMENTAL_BACKUP ]]; then
		echo "You have to specify the type of backup to do (full or incremental)"
		exit 1
	elif [[ $INCREMENTAL_BACKUP == "false" ]]; then
		add_option "F"
	fi

	# We do the backup using the repozo.py script
	print_message "Backing up $ZOPE_DATABASE"
	$PYTHON_BIN $REPOZO_SCRIPT $OPTIONS -B -r $BACKUP_DIRECTORY -f $ZOPE_DATABASE

elif [[ $ACTION == "restauration" ]]; then

	# If there is an actual Data.fs and the "-m" parameter is specified, we backup the current Data.fs
	if [[ -f $ZOPE_DATABASE && $MOVE_CURRENT_DATAFS == "yes" ]]; then
		DATE_FORMATED=`date --utc '+%Y-%m-%d-%H-%M-%S'`
		FS_FILE=$BACKUP_DIRECTORY/$DATE_FORMATED.fs
		DAT_FILE=$BACKUP_DIRECTORY/$DATE_FORMATED.dat

		# We move the actual Data.fs to the backup directory
		print_message "Moving $ZOPE_DATABASE to $FS_FILE"
		mv $ZOPE_DATABASE $FS_FILE

		# We now create the .dat file in order that repozo.py can use this Data.fs later, as a real backup
		print_message "Calculating the MD5 sum of $FS_FILE"
		echo -n "$FS_FILE 0 `ls -l $FS_FILE | cut -d ' ' -f 5`" > $DAT_FILE
		echo " `md5sum $FS_FILE | cut -d ' ' -f 1`" >> $DAT_FILE
	fi

	# We now retore the backup file
	print_message "Restoring $BACKUP_DIRECTORY/$BACKUP_FILE"
	$PYTHON_BIN $REPOZO_SCRIPT $OPTIONS -R -D $BACKUP_FILE -r $BACKUP_DIRECTORY -o $ZOPE_DATABASE

	# We set $ZOPE_USER as the owner and the group of the Data.fs
    print_message "Changing the permissions of $ZOPE_DATABASE"
	chown $ZOPE_USER:$ZOPE_USER $ZOPE_DATABASE

elif [[ $ACTION == "suppression" ]]; then
	delete_backup $BACKUP_FILE
fi