#!/bin/sh

set -e

# Local backup script (run as root)

echo "Creating mountpoint."
mkdir -p /mnt/disk_b/

echo "Preparing to decrypt backup disk..."
sleep 5
echo "Decrypting disk..."
cryptsetup luksOpen {{ backup_disk }} disk_b --key-file /k5e
echo "Disk decrypted."

echo "Mounting backup disk."
mount /dev/mapper/disk_b /mnt/disk_b

if ! mountpoint -q /mnt/disk;
then
	echo "Missing data disk mount!"
	exit
fi

if [ ! -f /mnt/disk_b/bk-0.tgz ]
then
	echo "No full archive: preparing to perform complete backup."
	sleep 5
	echo "Performing complete backup."
	tar -czvf /mnt/disk_b/bk-0.tgz -g /mnt/disk_b/bk.snar /mnt/disk
	echo "Backup finished."
	tput bel
else
	LABEL=$(date +"%Y_%m_%d")
	echo "Preparing to perform incremental backup: $LABEL"
	sleep 5.
	echo "Performing incremental backup."
	cp /mnt/disk_b/bk.snar "/mnt/disk_b/bk-$LABEL.snar"
	tar -czvf /mnt/disk_b/bk-0.tgz -g /mnt/disk_b/bk.snar /mnt/disk
	echo "Backup finished."
	tput bel
fi

echo "Preparing to unmount backup disk."
sleep 5
echo "Unmounting backup disk."
umount /mnt/disk_b
echo "Unmounted backup disk."

echo "Preparing to close backup disk."
sleep 5
echo "Closing backup disk."
cryptsetup luksClose /dev/mapper/disk_b
echo "Disk closed."