{ config, lib, pkgs, ... }:

with lib;

let
  cfg = config.custom.services.zigbee2mqtt;

  configJSON = pkgs.writeText "configuration.json" (builtins.toJSON
    (recursiveUpdate cfg.config config.services.zigbee2mqtt.config));
  configFile =
    pkgs.runCommand "configuration.yaml" { preferLocalBuild = true; } ''
      ${pkgs.remarshal}/bin/json2yaml -i ${configJSON} -o $out
    '';

  # the default config contains all required settings,
  # so the service starts up without crashing.
  defaultConfig = {
    homeassistant = false;
    permit_join = false;
    mqtt = {
      base_topic = "zigbee2mqtt";
      server = "mqtt://localhost:1883";
    };
    serial.port = "/dev/ttyACM0";
    # put device configuration into separate file because configuration.yaml
    # is copied from the store on startup
    devices = "devices.yaml";
  };
in
{
  options.custom.services.zigbee2mqtt = {
    enable = mkEnableOption "enable zigbee2mqtt service";

    package = mkOption {
      description = "ignored";
      default = pkgs.zigbee2mqtt.override { dataDir = cfg.dataDir; };
      defaultText = "pkgs.zigbee2mqtt";
      type = types.package;
    };

    dataDir = mkOption {
      description = "Zigbee2mqtt data directory";
      default = "/var/lib/zigbee2mqtt";
      type = types.path;
    };

    config = mkOption {
      default = { };
      type = with types; nullOr attrs;
      example = literalExample ''
        {
          homeassistant = config.services.home-assistant.enable;
          permit_join = true;
          serial = {
            port = "/dev/ttyACM1";
          };
        }
      '';
      description = ''
        Your <filename>configuration.yaml</filename> as a Nix attribute set.
      '';
    };
  };

  config = mkIf (cfg.enable) {

    virtualisation.oci-containers.containers.zigbee2mqtt = {
      image = "koenkk/zigbee2mqtt:1.18.1";
      volumes = [
        "${cfg.dataDir}:/app/data"
        #"/run/udev:/run/udev:ro"
      ];
      extraOptions = [
        "--device=${cfg.config.serial.port}" # /dev/ttyUSB0
        "--network=host"
        #"--privileged=true"
      ];
      environment = { TZ = "Europe/Amsterdam"; };
      #ports = [ "127.0.0.1:${toString frontPort}:80" ];
    };

    # create config before staring container
    systemd.services.docker-zigbee2mqtt = {
      preStart = ''
        cp --no-preserve=mode ${configFile} "${cfg.dataDir}/configuration.yaml"
      '';
    };

    #systemd.services.zigbee2mqtt = {
    #  description = "Zigbee2mqtt Service";
    #  wantedBy = [ "multi-user.target" ];
    #  after = [ "network.target" ];
    #  environment.ZIGBEE2MQTT_DATA = cfg.dataDir;
    #  serviceConfig = {
    #    ExecStart = "${cfg.package}/bin/zigbee2mqtt";
    #    User = "zigbee2mqtt";
    #    WorkingDirectory = cfg.dataDir;
    #    Restart = "on-failure";
    #    ProtectSystem = "strict";
    #    ReadWritePaths = cfg.dataDir;
    #    PrivateTmp = true;
    #    RemoveIPC = true;
    #  };
    #  preStart = ''
    #    cp --no-preserve=mode ${configFile} "${cfg.dataDir}/configuration.yaml"
    #  '';
    #};

    #users.users.zigbee2mqtt = {
    #  home = cfg.dataDir;
    #  createHome = true;
    #  group = "zigbee2mqtt";
    #  extraGroups = [ "dialout" ];
    #  uid = config.ids.uids.zigbee2mqtt;
    #};

    #users.groups.zigbee2mqtt.gid = config.ids.gids.zigbee2mqtt;
  };
}