#!/bin/sh

set -e

SNAP_ID=$1
SNAP_MOUNTPOINT="$2"
SNAP_ORIG_PATH="$5"
SNAP_ORIG_PATH_SAN=$(echo "$SNAP_ORIG_PATH" | sed 's@/@_@g')

CDIR=`dirname $0`

get_path()
{
        echo $1/$2 | sed 's@//@/@g'
}

remove_overlay() {
	if test -e $(get_path "$SNAP_ORIG_PATH" "/.overlay_2fefd007-3e48-4162-b2c6-45ccdda22f37_$SNAP_ID")
	then
		LODEV=`losetup -j $(get_path "$SNAP_ORIG_PATH" "/.overlay_2fefd007-3e48-4162-b2c6-45ccdda22f37_$SNAP_ID") | cut -d':' -f1`
		if [ "x$LODEV" != x ]
		then
			losetup -d $LODEV
		fi
		rm $(get_path "$SNAP_ORIG_PATH" "/.overlay_2fefd007-3e48-4162-b2c6-45ccdda22f37_$SNAP_ID")
	fi
}

if ! test -e $SNAP_MOUNTPOINT
then
    echo "Snapshot at $SNAP_MOUNTPOINT was already removed"
    [ ! -e $(get_path "$SNAP_ORIG_PATH" "/.datto_3d41c58e-6724-4d47-8981-11c766a08a24_$SNAP_ID") ] || rm $(get_path "$SNAP_ORIG_PATH" "/.datto_3d41c58e-6724-4d47-8981-11c766a08a24_$SNAP_ID")
    [ ! -e "${SNAP_MOUNTPOINT}-num" ] || rm "${SNAP_MOUNTPOINT}-num"
	remove_overlay
    exit 0
fi

TYPE=$(df -T -P | egrep " ${SNAP_MOUNTPOINT}\$" | head -n 1 | tr -s " " | cut -d" " -f2)

if [ "x$TYPE" = "x" ]
then
        if btrfs subvolume list -o "$SNAP_MOUNTPOINT" > /dev/null 2>&1
        then
                TYPE="btrfs"
        fi
fi

if [ "x$TYPE" = "xbtrfs" ]
then
    $CDIR/btrfs_remove_filesystem_snapshot "$@"
    exit $?
fi

if ! df -T -P | egrep " ${SNAP_MOUNTPOINT}\$" > /dev/null 2>&1
then
    echo "Snapshot is not mounted. Already removed"
    rm "${SNAP_MOUNTPOINT}-num"
    rmdir "${SNAP_MOUNTPOINT}"
    [ ! -e $(get_path "$SNAP_ORIG_PATH" "/.datto_3d41c58e-6724-4d47-8981-11c766a08a24_$SNAP_ID") ] || rm $(get_path "$SNAP_ORIG_PATH" "/.datto_3d41c58e-6724-4d47-8981-11c766a08a24_$SNAP_ID")
    remove_overlay
    exit 0
fi

NUM=`cat "${SNAP_MOUNTPOINT}-num"` || true

if [ "x$NUM" = "x" ]
then
    echo "Cannot get device number from ${SNAP_MOUNTPOINT}-num"
    exit 1
fi

echo "Unmounting /dev/datto$NUM at /mnt/urbackup_snaps/$SNAP_ID..."

if ! umount /mnt/urbackup_snaps/$SNAP_ID
then
	lsof | grep /mnt/urbackup_snaps/$SNAP_ID || true
    echo "Unmounting /mnt/urbackup_snaps/$SNAP_ID failed. Retrying in 10s..."
    sleep 10
    umount /mnt/urbackup_snaps/$SNAP_ID
fi


rm "${SNAP_MOUNTPOINT}-num"
rm "${SNAP_MOUNTPOINT}-dev"
rmdir "${SNAP_MOUNTPOINT}"

echo "Removing devicemapper snapshot..."

dmsetup remove "wsnap-$SNAP_ID"

remove_overlay

echo "Transitioning dattobd snapshot /dev/datto$NUM to incremental..."

dbdctl transition-to-incremental $NUM

exit 0