{ pkgs, lib, ... }:
let

  # https://www.zigbee2mqtt.io/devices/SPZB0001.html
  allDevices = {
    "heater1" = { id = "0x00158d00032f5ee4"; }; # office
    "heater2" = { id = "0x00158d00032f5f9f"; }; # office (kitchen)
    "heater3" = { id = "0x00158d00032f6d1e"; }; # bed room
    "heater4" = { id = "0x00158d00032f604d"; }; # abstell raum
  };

  # -t "zigbee2mqtt/heater3/set"   -m '{"system_mode":"auto","current_heating_setpoint":23}'
  # -t "zigbee2mqtt/heater3/set"   -m '{"system_mode":"off"}'

in {

  services.zigbee2mqtt.devices = lib.mapAttrs' (name:
    { id, ... }: {
      name = id;
      value = {
        retain = false;
        friendly_name = name;
        transition = 1;
      };
    }) allDevices;

  services.homeAssistantConfig = {

    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);

  };

}