#! /bin/zsh

TIMESTAMP=($(basename "$(pwd)"))
OUTDIR="$1"
KEYFILE="$2"

function die {
	>&2 echo "$2"
	exit $1
}

[[ "$0" != "./unpack.sh" ]] && die 1 "This can only be executed from the snapshot directory itself."
[[ ! -d "$OUTDIR" ]]       && die 1 "The first argument must be a directory to unpack subvolumes into."
[[ ! -f "$KEYFILE" ]]      && die 1 "The second argument must be a readable keyfile."
./check-integrity.sh       || die 2 "This snapshot failed integrity checks."

### end of checks

for ARCHIVE in *btrfs.zst.aes
do
	openssl enc -d -aes-256-cbc -pbkdf2 -salt -pass "file:$KEYFILE" < "$ARCHIVE" | zstd -d | btrfs receive "$OUTDIR" || die 3 "Failed to unpack subvolume."
	SUBVOL_NAME=${ARCHIVE%%.btrfs.zst.aes}
	mv "${OUTDIR}/${SUBVOL_NAME}" "${OUTDIR}/${SUBVOL_NAME}.${TIMESTAMP[1]}" || die 4 "Failed to rename subvolume."
done