#!/usr/bin/env bash
day="$(date -I)"
drivelist="$(grep -F "data d" /etc/snapraid.conf | grep -Po "(?<=/mnt/snapshot/)[[:alnum:]]*")"
param=$1

function create {
    echo "$drivelist" | while IFS="" read -r serial; do
        drive="/mnt/drives/${serial}"
        if [[ ! -s "${drive}/snapraid?.parity" ]]; then
            if [[ ! -d "${drive}/.snapshot/${day}" ]]; then
                btrfs subvolume snapshot -r "$drive" "${drive}/.snapshot/${day}"
                ln -nsfr "${drive}/.snapshot/${day}" "/mnt/snapshot/${serial}"
            fi
        fi
    done
}

function delete {
    echo "$drivelist" | while IFS="" read -r serial; do
        drive="/mnt/drives/${serial}"
        snapshots="$(ls -1 -d "${drive}/.snapshot/"* | head -n -1)"
        echo "$snapshots" | while IFS="" read -r snap; do
            btrfs subvolume delete "$snap"
        done
    done
}

if [[ "$param" == "create" ]]; then
    create
elif [[ "$param" == "delete" ]]; then
    delete
fi