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{
  pkgs,
  lib,
  config,
  ...
}:
let
  cfg = config.services.myapp;
  pkg = pkgs.callPackage ./pkg.nix { inherit pkgs; };
in
{
  options =
    let
      inherit (lib) mkEnableOption mkOption types;
    in
    {
      services.myapp = {
        enable = mkEnableOption "Enable myapp";

        package = mkOption {
          type = types.package;
          description = "myapp package to use";
          default = pkg;
        };

		boolFlagF = mkOption {
		  type = types.bool;
		  description = "Bool flag false";
		};
		boolFlagT = mkOption {
		  type = types.bool;
		  description = "Bool flag true";
		  default = true;
		  
		};
		durationFlag = mkOption {
		  type = types.str;
		  description = "Duration flag with no default";
		  default = "";
		  
		};
		durationFlagDefault = mkOption {
		  type = types.str;
		  description = "Duration flag with default";
		  default = "5m0s";
		  
		};
		intFlag = mkOption {
		  type = types.int;
		  description = "Int flag with no default";
		};
		intFlagDefault = mkOption {
		  type = types.int;
		  description = "Int flag with default";
		  default = 100;
		  
		};
		stringFlag = mkOption {
		  type = types.str;
		  description = "String flag with no default";
		  default = "";
		  
		};
		stringFlagDefault = mkOption {
		  type = types.str;
		  description = "String flag with default";
		  default = "string default";
		  
		};
		

        user = mkOption {
          type = types.str;
          default = "myapp";
          description = "User account under which myapp runs";
        };

        group = mkOption {
          type = types.str;
          default = "myapp";
          description = "Group account under which myapp runs";
        };
    };
  config = lib.mkIf cfg.enable {
    users.users."${cfg.user}" = {
      home = "/var/lib/myapp";
      createHome = true;
      group = "${cfg.group}";
      isSystemUser = true;
      isNormalUser = false;
      description = "user for myapp service";
    };
    users.groups."${cfg.group}" = { };

    systemd.services = {
      myapp = {
        enable = true;
        script =
          let
            args = [
              
              "--bool-flag-f=${cfg.boolFlagF}"
              
              "--bool-flag-t=${cfg.boolFlagT}"
              
              "--duration-flag=${cfg.durationFlag}"
              
              "--duration-flag-default=${cfg.durationFlagDefault}"
              
              "--int-flag=${cfg.intFlag}"
              
              "--int-flag-default=${cfg.intFlagDefault}"
              
              "--string-flag=${cfg.stringFlag}"
              
              "--string-flag-default=${cfg.stringFlagDefault}"
              
            ];
          in
          "${cfg.package}/bin/myappd ${builtins.concatStringsSep " " args}";
        wantedBy = [ "multi-user.target" ];
        after = [ "network.target" ];
        path = [
          cfg.package
        ];
        serviceConfig = {
          User = cfg.user;
          Group = cfg.group;
          Restart = "always";
          RestartSec = "15";
          WorkingDirectory = "/var/lib/myapp";
        };
      };
    };
  };
}