#!/usr/bin/env mksh
# Script by Ypnose - http://ywstd.fr
# $ ( cd /mnt && backup -f FILELIST -t $HOME BACKUP )

BACK_DATE="$(date '+%Y-%m-%d')"

function p_err {
	print -u2 -- "$1"
	exit 1
}

function usage {
	print "usage: backup [-d] [-f FILELIST] [-h] [-t] [SRC] [DEST]"
	exit
}

if [[ $1 = "-h" ]]; then
	usage
fi

if [[ ! -x $(whence -p rsync) ]]; then
	p_err "rsync not found in the PATH"
fi

while getopts ":df:t" opt; do
	case $opt in
		d)
			BACK_DRYR="1"
			BACK_OPTS+=(--dry-run --log-file=/dev/null)
			;;
		f)
			BACK_INCL="$OPTARG"
			;;
		t)
			BACK_SQSH="1"
			;;
		*)
			usage
			;;
	esac
done
shift $(( OPTIND - 1 ))

# SRC and DEST are required
if (( $# < 2 )); then
	usage
fi

BACK_DEST="$2"

if [[ ! -d $BACK_DEST ]]; then
	p_err "$BACK_DEST directory is missing"
fi

if [[ -z $BACK_INCL ]]; then
	p_err "No include file provided"
elif [[ ! -r $BACK_INCL ]]; then
	p_err "$BACK_INCL is either missing or unreadable"
fi

# Check rsync(1) man page for pattern rules
# With '--files-from', '-r' needs to be specified explicitly
rsync \
	-ahrvHX \
	--checksum \
	--delete \
	--delete-delay \
	--exclude=".gnupg/random_seed" \
	--exclude=".gnupg/S.*" \
	--exclude="*.dump" \
	--exclude="*.qcow2*" \
	--exclude="*.raw" \
	--exclude="Desktop/" \
	--exclude="Downloads/" \
	--files-from="$BACK_INCL" \
	--log-file="${BACK_DEST}/rsync-${BACK_DATE}.log" \
	--numeric-ids \
	--stats \
	"${BACK_OPTS[@]}" \
	"$1" "$BACK_DEST"

# Create a Squashfs filesystem only if it's not dry run
if (( BACK_SQSH == 1 && BACK_DRYR != 1 )); then
	sleep 5
	mksquashfs \
		"$BACK_DEST" \
		"BACKUP-$(hostname)-${BACK_DATE}.sqsh" \
		-comp gzip \
		-keep-as-directory \
		-reproducible \
		-xattrs
fi

exit