## arg 1:  the new package version
pre_install() {
    :
}

## arg 1:  the new package version
post_install() {
    # We start and enable snapd.socket so it immediately is usable and the
    # service is started on-demand on future boots. The timer is started so
    # that snaps are automatically refreshed (updated) as new versions are
    # published in the store.
    systemctl enable snapd.refresh.timer
    systemctl enable snapd.socket
    systemctl start  snapd.refresh.timer
    systemctl start  snapd.socket
}

## arg 1:  the new package version
## arg 2:  the old package version
pre_upgrade() {
    :
}

## arg 1:  the new package version
## arg 2:  the old package version
post_upgrade() {
    :
}

## arg 1:  the old package version
pre_remove() {
    # We stop the socket and disable it to remove the symlink that would start
    # it at boot.
    systemctl stop    snapd.socket
    systemctl disable snapd.socket
    systemctl stop    snapd.refresh.timer
    systemctl disable snapd.refresh.timer
}

## arg 1:  the old package version
post_remove() {
    # We clean up all the snap mounts created by snappy
    find /etc/systemd/system -name "snap-*.mount" -delete
    find /etc/systemd/system -name "snap*.service" -delete

    # As well as their symlinks from the multi-user target
    find /etc/systemd/system/multi-user.target.wants -name "snap-*.mount" -delete
    find /etc/systemd/system/multi-user.target.wants -name "snap*.service" -delete

    # We unmount all currently mounted snaps
    if [ -n "$(mount | grep snap | awk '{print $3}')" ]; then
        umount $(mount | grep snap | awk '{print $3}')
    fi

    # We remove the /snap directory as well as state of snappy and its snap cache
    rm -rf /snap
    rm -rf /var/lib/snapd
}