#!/bin/bash

# Load config 

if [ ! -f /etc/default/backupfs ]; then
	echo "/etc/default/backupfs missing"
	exit 1
fi

. /etc/default/backupfs

declare -A dumptool
dumptool[ext2]=dump
dumptool[ext3]=dump
dumptool[ext4]=dump
dumptool[btrfs]=btrfs

adjustpath ()
{
		havesbin=1
		haveusrsbin=1
		for i in `echo $PATH|tr : " "`;do
				[ "$i" == "/sbin" ] && havesbin=0
				[ "$i" == "/usr/sbin" ] && haveusrsbin=0
		done
		[ $havesbin -eq 0 ] || export PATH="/sbin:$PATH"
		[ $haveusrsbin -eq 0 ] || export PATH="/usr/sbin:$PATH"
}

checkdeps ()
{
	which curl > /dev/null
	if [ $? -ne 0 ]; then
		echo "curl missing, existing"
		exit 1
	fi
	which gpg > /dev/null
	if [ $? -ne 0 ]; then
		echo "gpg missing, existing"
		exit 1
	fi
	for fs in "${!dumptool[@]}"; do
		if [ -n "`mount -t $fs`" ]; then
			which ${dumptool[$fs]} > /dev/null
			if [ $? -ne 0 ]; then
				echo "You have a $fs filesystem but ${dumptool[$fs]} is missing"
				exit 1
			fi
		fi
	done
}

checkval ()
{
	if [ -z "$url" ]; then
		echo "No target url specified, exiting"
		exit 1
	fi
	if [ -z "$encryptto" ]; then
		echo "No encrypt to specified, exiting"
		exit 1
	fi
	gpg --list-key "$encryptto" > /dev/null
	if [ $? -ne 0 ]; then
		gpg --recv-keys "$encryptto"
		gpg --list-key "$encryptto" > /dev/null
		if [ $? -ne 0 ]; then
			echo "PGP key missing"
			exit 1
		fi
	fi
}

lock ()
{
	PID=`cat ~/.backuplock 2> /dev/null`
	if [ -n "$PID" ]; then
		if [ -d "/proc/$PID" ]; then
			if [ "`readlink /proc/$PID/exe`" == "/bin/bash" ]; then
				echo "Locked, exiting"
				exit 1
			fi
		fi
	fi
	echo -n $$ > ~/.backuplock
}

fsdetect ()
{
  local mountpoint=${1}
	local device="`mount |grep " on $mountpoint "|cut -d\  -f1`"
	fstype=`/sbin/blkid -o value -s TYPE ${device}`
}

mptobname ()
{
	# mountpoint
	bname="`echo ${1}|tr / _`"
}

mptofname ()
{
	# mountpoint, level, extension
	hn=`hostname`
	fname="`echo ${hn}-${date}-${1}-${2}.${3}|tr / _`"
}

checkbtrfs ()
{
	true
}

docurl ()
{
  local source="${1}"
  local destination="${2}"
	curl --no-buffer --data-binary @"${source}" -XPUT $url/"${destination}"
}

dumpbtrfs ()
{
	mountpoint=${1}
	checkbtrfs
	mptobname ${mountpoint} ${level}
	# TODO del if exists
	btrfs subvolume snapshot -r ${mountpoint} /snapshot/current
	btrfs subvolume snapshot -r /snapshot/current /snapshot/$bname-$level
	btrfs subvolume delete /snapshot/current

	fname="${hostname}-${date}-${bname}-${level}.snap.gpg"
  if [ $level -eq 0 ]; then
		#btrfs send /snapshots/$bname-$level | xz -6e -T0|gpg --encrypt -r dev@mailchuck.com " | docurl "${fname}"
		true
	else
		plevel=$(($level - 1))
		#btrfs send -p /snapshots/$bname-$plevel /snapshots/$bname-$level | xz -6e -T0|gpg --encrypt -r $encryptto | docurl "${fname}"
		true
	fi
}

dumpextfs ()
{
	mountpoint=${1}
	mptobname ${mountpoint} ${level}
	fname="${hostname}-${date}-${bname}-${level}.dump.gpg"
	tmp_file="$(mktemp)"
	echo "dumping $mountpoint into $fname (temp $tmp_file)"
	dump -${level}uj -h 0 ${mountpoint} -f -|gpg --encrypt -r $encryptto > "${tmp_file}"
  docurl "${tmp_file}" "${fname}"
	rm -f "${tmp_file}"
}

dodump ()
{
	for fs in "${!dumptool[@]}"; do
		for mpt in `mount -t $fs|cut -d\  -f3`; do
			if [ -z "$mpt" ]; then
				continue
			fi
			echo "Dumping $mpt as $fs"
			if [ "$fs" == "btrfs" ]; then
				dumpbtrfs $mpt $level
			elif [ "$fs" == "ext2" -o "$fs" == "ext3" -o "$fs" == "ext4" ]; then
				dumpextfs $mpt $level
			fi
		done
	done
}

adjustpath
checkdeps
checkval
umask 077
renice 19 $$ &> /dev/null
ionice -c 3 -p $$
lock

#date=`date +%y-%m-%d`
hostname=`hostname|cut -d. -f1`
dom=`date +%d`
dow=`date +%w`
date=`date +%y%m%d`
level=$(($dow+1))
if [ $dow -eq 0 ];then # sunday
	if [ $dom -le 7 ];then # first sunday in month
		level=0
	else
		level=1
	fi
fi
if [ "$1" == "0" -o "$1" == "1" -o "$1" == "2" ]
then
	level="$1"
fi

dodump

rm ~/.backuplock

echo "All OK"
exit 0

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