post_install() {
  # create user and set ownership
  useradd -d /opt/anki-sync-server -r -s /sbin/nologin anki-sync-server
  chown -R anki-sync-server /opt/anki-sync-server
  chgrp -R anki-sync-server /opt/anki-sync-server

  # link systemd service file
  ln -s /opt/anki-sync-server/plugins/systemd/anki-sync-server.service /etc/systemd/system/
  systemctl enable anki-sync-server
  systemctl start anki-sync-server

  # install prerequisites as stated on the website
  sudo -u anki-sync-server pip install -r /opt/anki-sync-server/anki-bundled/requirements.txt --user 
  sudo -u anki-sync-server pip install webob --user

  # post installation instructions
  cat << EOF 
=======================================================================
------------------
Post Installation:
------------------
You'll need to go to:

    /opt/anki-sync-server

and run:

    sudo -u anki-sync-server ./ankisyncctl.py adduser <username>

to add a new user to the anki database.

--------------------
Plugin Installation:
--------------------
To have anki interface with the server, you'll need to copy the plugin
from /opt/anki-sync-server/plugins to the relevant directory.

Anki 2.1: ~/.local/share/Anki2/addons21/
    ln -s /opt/anki-sync-server/plugins/anki2.1/ankisyncd \\
        ~/.local/share/Anki2/addons21/

Anki 2.0: ~/Anki/addons
    ln -s /opt/anki-sync-server/plugins/anki2.0/anki-sync-server.py \\
        ~/Anki/addons

or your OS equivalent.

---------------
Run The Server:
---------------
To just run the server, go to:

    /opt/anki-sync-server/

then run:

    python -m ankisyncd

The server is set to auto start on boot.
See:

    systemctl status anki-sync-server

for details.

------------------------
Run Bundled Anki Client:
------------------------
execute:

    /opt/anki-sync-server/anki-bundled/runanki
=======================================================================
EOF
}

post_remove(){
  # stop service (and remove systemd files)
  systemctl stop anki-sync-server
  systemctl disable anki-sync-server
  echo "Executing systemctl daemon-reload"
  systemctl daemon-reload

  # remove user (& group)
  getent passwd anki-sync-server &>/dev/null && userdel anki-sync-server || true
  getent group anki-sync-server &>/dev/null && groupdel anki-sync-server || true

  echo "==================================================================="
  echo "rm -rf /opt/anki-sync-server to remove the database and cache files"
  echo "==================================================================="
}

post_upgrade(){
  chown -R anki-sync-server /opt/anki-sync-server
  chgrp -R anki-sync-server /opt/anki-sync-server
}