#!/bin/bash

set -ex

if [[ $EUID -ne 0 ]]; then
    echo "This script must be run as root" 1>&2
    sudo $0 $1 $2 $3 $4 $5 $6 $7 $8 $9
    exit 0
fi
echo "Als root Angemeldet"

if [ "make" == "$1" ]; then

    while (( "$(expr $# - 1)" ))
    do

        pfad="${2}"

        echo `date "+%Y%m%d-%H%M%S"` > /run/btrfs-root/__current/${pfad}/SNAPSHOT
        echo "BACKUP" >> /run/btrfs-root/__current/${pfad}/SNAPSHOT

        mkdir -p /run/btrfs-root/__snapshot/${pfad%/*}
        btrfs subvolume snapshot -r /run/btrfs-root/__current/${pfad} /run/btrfs-root/__snapshot/${pfad}@`head -n 1 /run/btrfs-root/__current/${pfad}/SNAPSHOT`

        rm /run/btrfs-root/__current/${pfad}/SNAPSHOT

        shift

    done

elif [ "restore" == "$1" ]; then

    while (( "$(expr $# - 1)" ))
    do

        pfad="${2}"

        if [ -d /run/btrfs-root/__current/${pfad/@*}.old ]; then
            btrfs subvolume delete /run/btrfs-root/__current/${pfad/@*}.old
        fi
        mv /run/btrfs-root/__current/${pfad/@*} /run/btrfs-root/__current/${pfad/@*}.old
        btrfs subvolume snapshot /run/btrfs-root/__snapshot/${pfad} /run/btrfs-root/__current/${pfad/@*}

        shift

    done


    btrfs subvolume list -p /

    #echo "Bitte noch die /etc/fstab editieren und die neuen IDs eintragen!!!"

    echo "Bitte damit die Änderungen wirksam werden das System neustarten!!!"

    #reboot

else

    echo "bash ./snapshot.sh PARAMETER PFAD"
    echo "Parameters: make restore"
    echo "make ROOT home opt var/cache/pacman/pkg"
    echo "restore ROOT@20170725-235544 home@20170725-235544 opt@20170725-235544 var/cache/pacman/pkg@20170725-235544"

    btrfs subvolume list -p /

fi