{
  pkgs,
  hcpy-raw,
  ...
}:
pkgs.writeShellApplication rec {
  name = "hcpy";
  runtimeInputs = with pkgs; [gnugrep coreutils-full];
  text = ''
    #/ Usage: ${name} <ACTION> [ARGUMENTS] [OPTIONS]
    #/
    #/ This is a very, very beta interface for Bosch-Siemens Home Connect
    #/ devices through their local network connection.  Unlike most
    #/ IoT devices that have a reputation for very bad security, BSG seem to have
    #/ done a decent job of designing their system, especially since
    #/ they allow a no-cloud local control configuration.  The protocols
    #/ seem sound, use well tested cryptographic libraries (TLS PSK with
    #/ modern ciphres) or well understood primitives (AES-CBC with HMAC),
    #/ and should prevent most any random attacker on your network from being able to
    #/ [take over your appliances to mine cryptocurrency](http://www.antipope.org/charlie/blog-static/2013/12/trust-me.html).
    #/
    #/ Actions:
    #/ - login <USERNAME> <PASSWORD> <OUTPUT-FILE> - initializes the JSON <OUTPUT-FILE> which contains a list of devices assigned to specified account.
    #/ - run                                       - starts the bridge connection between appliances and MQTT broker
    #/
    #/ Options for 'run' action:
    #/   -d, --devices_file - file generated by "login" action, default="config/devices.json"
    #/   -h, --mqtt_host    - MQTT broker host, default="localhost"
    #/   -p, --mqtt_prefix  - MQTT broker prefix, default="homeconnect/"
    #/   --mqtt_port        - MQTT broker port, default=1883
    #/   --mqtt_username    - MQTT client username
    #/   --mqtt_password    - MQTT client password
    #/   --mqtt_ssl         - use SSL connection to MQTT broker
    #/   --mqtt_cafile      - CA certifications file for SSL connection
    #/   --mqtt_certfile    - certification file for SSL connection
    #/   --mqtt_keyfile     - certification key file for SSL connection
    #/   --mqtt_clientname  - name of MQTT broker client, default="hcpy1"
    #/   --domain_suffix    - the suffix of the domain, default=""
    #/   --debug/--no-debug - enable debug mode
    #/   --ha-discovery     - enable HomeAssistant discovery

    usage() { grep '^#/' "''${BASH_SOURCE[0]}" | cut -c4- ; exit 0 ; }
    expr "$*" : ".*--help" > /dev/null && usage

    if [ "$#" -eq 0 ]; then
      echo "Expected action: login or run." >&2;
      usage
    fi

    action="$1";
    shift;

    case "$action" in
      login)
        exec ${hcpy-raw}/bin/hc-login "$@";
        ;;

      run)
        exec ${hcpy-raw}/bin/hc2mqtt "$@";
        ;;

      *)
        echo "Expected action: login or run." >&2;
        usage
    esac
  '';
}