{ pkgs, lib, ... }:
let

  # https://www.zigbee2mqtt.io/devices/MCCGQ11LM.html
  allDevices = {
    "door_sensor_1" = { id = "0x00158d000312dc52"; };
    "door_sensor_2" = { id = "0x00158d000316d5bf"; };
    "door_sensor_3" = { id = "0x00158d0002f9516f"; };
    "door_sensor_4" = { id = "0x00158d00031383b9"; };
    "door_sensor_5" = { id = "0x00158d0003120d3e"; };
  };

in
{

  services.zigbee2mqttConfiguration = lib.mapAttrs'
    (name:
      { id, ... }: {
        name = id;
        value = {
          retain = false;
          friendly_name = name;
        };
      })
    allDevices;

  services.homeAssistantConfig = {

    # define meta information sensors
    sensor = lib.flatten (lib.mapAttrsToList
      (name:
        { ... }: [
          {
            name = "battery_${name}";
            platform = "mqtt";
            state_topic = "zigbee2mqtt/${name}";
            availability_topic = "zigbee2mqtt/bridge/state";
            unit_of_measurement = "%";
            icon = "mdi:battery-10";
            value_template = "{{ value_json.battery }}";
          }
          {
            name = "link_${name}";
            platform = "mqtt";
            state_topic = "zigbee2mqtt/${name}";
            availability_topic = "zigbee2mqtt/bridge/state";
            icon = "mdi:signal";
            unit_of_measurement = "lqi";
            value_template = "{{ value_json.linkquality }}";
          }
        ])
      allDevices);

    binary_sensor = lib.mapAttrsToList
      (name:
        { ... }: {
          name = name;
          platform = "mqtt";
          device_class = "door";
          state_topic = "zigbee2mqtt/${name}";
          availability_topic = "zigbee2mqtt/bridge/state";
          payload_on = false;
          payload_off = true;
          value_template = "{{ value_json.contact}}";
        })
      allDevices;

    # create groups
    # -------------
    group =
      let
        # to have nice panels for every device
        sensorGroups = lib.mapAttrs
          (name:
            { ... }: {
              entities = [
                "binary_sensor.${name}"
                "sensor.battery_${name}"
                "sensor.link_${name}"
              ];
            })
          allDevices;
        # sort lights into given groups.
        sortedInGroups =
          let
            groupEntries = lib.zipAttrs (lib.flatten (lib.mapAttrsToList
              (name:
                { groups ? [ ], ... }:
                map (groupName: { "${groupName}" = "binary_sensor.${name}"; }) groups)
              allDevices));
          in
          lib.mapAttrs (name: entities: { inherit entities; }) groupEntries;
      in
      sortedInGroups // sensorGroups // {
        all_sensors.entities =
          lib.mapAttrsToList (name: { ... }: "binary_sensor.${name}") allDevices;
      };

  };

}