{ pkgs, lib, ... }:
let

  # https://www.zigbee2mqtt.io/devices/AC10787.html
  allDevices = {
    "light_1" = {
      id = "0x7cb03eaa0a0347b5";
      groups = [
        "floor_room"
        "floor_room_bright"
        "floor_room_essential"
        "floor_room_lights"
      ];
    };
    "light_2" = {
      id = "0x7cb03eaa0a0387b9";
      groups = [ "floor_room" ];
    };
    "light_3" = {
      id = "0x7cb03eaa0a033a86";
      groups = [ "living_room" ];
    };
    "light_4" = {
      id = "0x7cb03eaa0a04aabf";
      groups = [ "bath_room" ];
    };
    "light_5" = { id = "0x7cb03eaa0a0346e4"; };
    "light_6" = { id = "0x7cb03eaa0a034b46"; };
    "light_7" = { id = "0x7cb03eaa0a033b4f"; };
    "light_8" = {
      id = "0x7cb03eaa0a0384d3";
      groups = [ "bed_room" ];
    };
  };

in {

  services.zigbee2mqtt.devices = lib.mapAttrs' (name:
    { id, ... }: {
      name = id;
      value = {
        retain = false;
        friendly_name = name;
        osram_set_transition = 2; # time in seconds (integer or float)
      };
    }) allDevices;

  #services.homeAssistantConfig = {

  #  light = lib.mapAttrsToList (name:
  #    { ... }: {
  #      platform = "mqtt";
  #      name = name;
  #      state_topic = "zigbee2mqtt/${name}";
  #      availability_topic = "zigbee2mqtt/bridge/state";
  #      command_topic = "zigbee2mqtt/${name}/set";
  #      value_template = "{{ value_json.click }}";
  #      brightness = true;
  #      color_temp = true;
  #      schema = "json";
  #    }) allDevices;

  #  sensor = with lib;
  #    mapAttrsToList (name:
  #      { ... }: {
  #        name = "link_${name}";
  #        platform = "mqtt";
  #        state_topic = "zigbee2mqtt/${name}";
  #        availability_topic = "zigbee2mqtt/bridge/state";
  #        icon = "mdi:signal";
  #        value_template = "{{ value_json.linkquality}}";
  #      }) allDevices;

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

  #  # create groups
  #  # -------------
  #  group = let

  #    # to have nice panels for every device
  #    lightGroups = lib.mapAttrs (name:
  #      { ... }: {
  #        entities = [
  #          "light.${name}"
  #          "sensor.link_${name}"
  #          "binary_sensor.update_${name}"
  #        ];
  #      }) allDevices;

  #    # sort lights into given groups.
  #    sortedInGroups = let
  #      groupEntries = lib.zipAttrs (lib.flatten (lib.mapAttrsToList (name:
  #        { groups ? [ ], ... }:
  #        map (groupName: { "${groupName}" = "light.${name}"; }) groups)
  #        allDevices));
  #    in lib.mapAttrs (name: entities: { inherit entities; }) groupEntries;

  #  in sortedInGroups // lightGroups // {
  #    all_lights.entities =
  #      lib.mapAttrsToList (name: { ... }: "light.${name}") allDevices;
  #  };
  #};

}