post_upgrade() {

  if (( $(vercmp "0.5.18.r159.gda9287d7-2" "$2") > 0 )); then
    # needed because started before hooks
    systemd-tmpfiles --create

    if [[ -f /opt/headphones/config.ini && ! -f /var/lib/headphones/config.ini ]]; then
      cp -a {/opt,/var/lib}/headphones/config.ini
      echo "Copied config.ini from /opt/headphones/ -> /var/lib/headphones/"
    fi

    if [[ -f /opt/headphones/headphones.db && ! -f /var/lib/headphones/headphones.db ]]; then
      cp -a {/opt,/var/lib}/headphones/headphones.db
      echo "Copied headphones.db from /opt/headphones/ -> /var/lib/headphones/"
    fi

    if [[ -d /opt/headphones/logs && ! -d /var/lib/headphones/logs ]]; then
      cp -a {/opt,/var/lib}/headphones/logs
      echo "Copied logs from /opt/headphones/ -> /var/lib/headphones/"
    fi

    if [[ -d /opt/headphones/cache && ! -d /var/lib/headphones/cache ]]; then
      cp -a {/opt,/var/lib}/headphones/cache
      echo "Copied cache from /opt/headphones/ -> /var/lib/headphones/"
    fi
  fi

  if [[ "$( getent passwd headphones | cut -d: -f6 )" != "/var/lib/headphones" ]]; then
    usermod -d /var/lib/headphones headphones
    if [[ $? -ne 0 ]]; then
      echo "Could not change headphones users home directory."
      echo "Run: sudo systemctl stop headphones ; sudo usermod -d /var/lib/headphones headphones ; sudo systemctl start headphones"
    fi
  fi

  if [[ -d /opt/lazylibrarian ]]; then
    echo "Remove /opt/lazylibrarian if everything is working correctly from /var/lib/lazylibrarian now."
  fi
}