#!/bin/bash

function log {
	conf=`basename $config | sed 's/\.config$//'`
	[ "$dolog" = "1" ] && echo "`date` - $@" >> $logdir/${conf}.log
}

if [ -z "$1" ]; then
	echo usage: $0 configfile
	exit -1
fi

if [ ! -f $1 ]; then
	echo configfile $1 is not a file
	exit -2
fi

config=$1

host=`grep ^host $config | cut -d ' ' -f 2`
aliases="`grep ^aliases $config | cut -d ' ' -f 2-`"
user=`grep ^user $config | cut -d ' ' -f 2`
homedirs="` grep ^homedirs $config | cut -d ' ' -f 2-`"
extradirs="`grep ^extradirs $config | cut -d ' ' -f 2-`" 
replicas=`grep ^replicas $config | cut -d ' ' -f 2`
oldest=`grep ^oldest $config | cut -d ' ' -f 2`
data=`grep ^data $config | cut -d ' ' -f 2`
bandwidth=`grep ^bandwidth $config | cut -d ' ' -f 2`
bwconn="`grep ^bandwidth $config | cut -d ' ' -f 3-`"
compression=`grep ^compression $config | cut -d ' ' -f 2`
compconn="`grep ^compression $config | cut -d ' ' -f 3-`"
logdir=`grep ^logdir $config | cut -d ' ' -f 2`

dolog=0
if [ ! -z "$logdir" ]; then
	mkdir -p $logdir
	[ -d $logdir ] && dolog=1
fi

hit=0
for conn in $host $aliases; do
	ping -c1 $conn > /dev/null 2>&1
	ret=$?
	if [ "$ret" = "0" ]; then
		remote=$conn
		break
	fi
done
if [ -z "$remote" ]; then
	log "host $host ($aliases) unreachable ..."
	exit -3
else
	log "host $host (via $remote) is online ..."
fi

comp=6
if [ ! -z "$compression" ]; then
	comp=$compression
	for cpair in "$compconn"; do
		ch=`echo $cpair | cut -d ':' -f 1`
		if [[ "$remote" == "$ch"* ]]; then
			cl=`echo $cpair | cut -d ':' -f 2`
			[[ "$cl" == [0-9] ]] && comp=$cl
		fi
	done
fi
rcomp="-z --compress-level $comp"
log using compression level $comp ...

bw=0
if [ ! -z "$bandwidth" ]; then
	bw=$bandwidth
	for bwpair in "$bwconn"; do
		ch=`echo $bwpair | cut -d ':' -f 1`
		if [[ "$remote" == "$ch"* ]]; then
			bwl=`echo $cpair | cut -d ':' -f 2`
			[ ! -z "$bwl" ]] && bw=$bwl
		fi
	done
fi
rbw="--bandwidth=$bw"
log applying bandwidth of $bw ...

if [ ! -d $data ]; then
	log no data directory ...
	exit -4
fi
log backing up to $data ...

today=`date -I`
backupdir=$data/${user}_at_${host}

cbd=$backupdir/$today
mkdir -p $cbd

rsync="rsync -azR --delete --bwlimit=$bandwidth"

ob=""
for pb in $backupdir/[0-9]*; do
	bdd=`basename $pb`
	if [ ! -f $backupdir/.$bdd ]; then
		if [ "$pb" != "$cbd" ]; then
			rm -rf $cbd
			mv $pb $cbd
			log continuing $pb as $cbd ...
		fi

		rsrc=""
		for dir in $homedirs; do
			rsrc="$rsrc :/home/$user/$dir"
		done
		rsrc="`echo $rsrc | sed 's/^\ //'`"
		for dir in $extradirs; do
			rsrc="$rsrc :$dir"
		done
		[ ! -z "$homedirs" ] && \
			log backing up home directories $homedirs ...
		[ ! -z "$extradirs" ] && \
			log backing up directories $extradirs ...
		$rsync $user@$remote$rsrc $cbd
		ret=$?
		if [ "$ret" != "0" ]; then
			log backup terminated before completion ...
			exit -50
		fi
		
		touch $backupdir/.`basename $cbd`
		log "backup `basename $cbd` completed :)"
	else
		if [ "$pb" = "$cbd" ]; then
			log backup $bdd found completed ...
		fi
	fi
	ob="$ob $pb"
done

cob=`echo $ob | wc -w`
if [ $cob -gt $replicas ]; then
	((numdel=cob-replicas))
	todel="`echo $ob | cut -d ' ' -f 1-${numdel}`"
	log to delete: $todel
	#for dirdel in $todel; do
	#	bdd=`basename $dirdel`
	#	rm -r $dirdel
	#	rm $backupdir/$bdd
	#done
fi

exit 0