#!/bin/sh


# Make sure to look at sysmocom-restore to check if the file would
# be restored right. Currently only some dirs get restored.
FILES="etc/sysmocom/backup.d"

# Pick some extra files
if [ -e /etc/sysmocom/backup.d/ ]; then
	for extra in `ls /etc/sysmocom/backup.d/*.files`;
	do
		echo "Add extras from $extra."
		FILES="$FILES `cat $extra`"
	done
fi

DATE=`date +%Y%m%d`

# Called for a file. Compare with the content in /ro-root
# if this file has been modified and only take it then. In
# case the file is not present it in /ro-root it will be
# added to the backup set
backup_file() {
	cmp -s /$2 /ro-root/$2
	if [ $? -ne 0 ]; then
		echo "Adding $2"
		tar -rf $1 --transform='s,^,content/,' -C / $2
	fi
}

# Check if this is a file, otherwise descend
handle_file() {
	if [ -f "/$2" -a -e "/$2" ]; then
		backup_file $1 $2
	fi
	if [ -d "/$2" -a -e "/$2" ]; then
		for file in /$2/*;
		do
			# Construct to have no leading /
			handle_file $1 $2/`basename $file`
		done
	fi
}

do_backup_files() {
	BACKUP_FILE="/data/sysmocom-backup_$DATE.tar"

	# 0. Sanity checking
	if [ -e $BACKUP_FILE ]; then
		echo "The backup file '$BACKUP_FILE' already exists. Exiting!"
		exit 1
	fi

	# 1. Create an empty archive..
	tar -cf $BACKUP_FILE --files-from=/dev/null

	# 2. Add all the files... we need
	for file in $FILES;
	do
		handle_file $BACKUP_FILE $file
	done

	# 4. Generate more information
	NAME="/tmp/backup.$$"
	mkdir $NAME
	opkg list_installed > $NAME/installed_packages
	/sbin/ifconfig | grep HWaddr | cut -d ' ' -f 11 > $NAME/mac_addr

	# 5. Add the more information
	tar -rf $BACKUP_FILE --transform='s,^,info/,' -C $NAME installed_packages mac_addr

	# 6. Create stable link
	cd /data/
	ln -sf `basename $BACKUP_FILE` sysmocom-backup.tar

	# 76
	echo "The backup was stored to $BACKUP_FILE"
}

do_backup_files