{
  description = "NixOS system flake";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/release-24.11";
    #nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
    nixos-2405.url = "github:NixOS/nixpkgs/nixos-24.05";
    nixos-unstable.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixos-hardware.url = "github:NixOS/nixos-hardware/master";
    home-manager = {
      url = "github:nix-community/home-manager/master";
      #url = "github:nix-community/home-manager/release-24.11";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    lanzaboote = {
      url = "github:nix-community/lanzaboote/v0.3.0";
      # deliberately do _not_ follow the nixpkgs input here, because paranoia and test coverage
    };
    utils.url = "github:numtide/flake-utils";
    treefmt-nix = {
      url = "github:numtide/treefmt-nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    nix-darwin = {
      url = "github:LnL7/nix-darwin";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    nur.url = "github:nix-community/NUR";
    # TODO: possible make this a flake as well
    mysecrets = {
      flake = false;
      url = "git+ssh://gitea@git.orlives.de:2342/schmittlauch/home-manager_secrets.git";
    };
  };

  outputs =
    {
      self,
      nixpkgs,
      nur,
      lanzaboote,
      utils,
      home-manager,
      treefmt-nix,
      nix-darwin,
      ...
    }@inputs:
    let
      # FIXME: allow different systems
      systems = utils.lib.system;
      # necessary to make the top-level inputs available to system configuration
      # inspired by https://jade.fyi/blog/flakes-arent-real/
      inputInjection =
        { pkgs, lib, ... }:
        {
          options.inputInjection = lib.mkOption {
            type = with lib.types; attrsOf unspecified;
            default = { };
          };
          config.inputInjection = {
            flake-inputs = inputs;
          };
        };
      defaultModules = system: [
        inputInjection

        # for some reason, `imports`-ing the home-manager module via inputInjection
        # from a sub-module causes infinite recursion, so importing it here instead
        home-manager.nixosModules.home-manager
      ];
      mkSystem =
        system: extraModules:
        nixpkgs.lib.nixosSystem rec {
          modules = (defaultModules system) ++ extraModules;
          inherit system;
          specialArgs = {
            inherit system;
          };
        };
      mkHomeManager =
        confName: user: system: # unfortunately, home-manager configs are still system-specific
        home-manager.lib.homeManagerConfiguration {
          pkgs = nixpkgs.legacyPackages.${system};
          modules = [
            {
              imports = [
                nur.hmModules.nur
                ./home/common.nix
                ./home/${confName}.nix
              ];
              # extends the home config
              home.username = user;
            }
          ];
          # Optionally use extraSpecialArgs
          # to pass through arguments to home.nix
          extraSpecialArgs = {
            inherit inputs system;
          };
        };
      treefmtConf =
        { pkgs, ... }:
        {
          projectRootFile = "flake.nix";
          programs.nixfmt.enable = true;
        };
    in
    {
      overlays.default = import ./packages;
      nixosConfigurations = {
        thinknix = mkSystem systems.x86_64-linux [
          ./hosts/thinknix
          inputs.nixos-hardware.nixosModules.lenovo-thinkpad-t440s
          lanzaboote.nixosModules.lanzaboote
        ];
        framenix = mkSystem systems.x86_64-linux [
          ./hosts/framenix
          inputs.nixos-hardware.nixosModules.framework-13-7040-amd
          lanzaboote.nixosModules.lanzaboote
        ];
      };
      darwinConfigurations."OS-MacBook-Pro" = nix-darwin.lib.darwinSystem {
        modules = [
          ./darwin/configuration.nix
          inputInjection

        ];
      };
      homeConfigurations = {
        spiollinux-desktop = mkHomeManager "desktop" "spiollinux" systems.x86_64-linux;
        os-workmac = mkHomeManager "workmac" "os" systems.aarch64-darwin;
      };
      lib = {
        inherit mkHomeManager;
      };
    }
    // utils.lib.eachDefaultSystem (
      system:
      let
        nixpkgs = import inputs.nixpkgs {
          inherit system;
          overlays = nixpkgs.lib.attrValues self.overlays;
        };
        nixpkgs_unstable = import inputs.nixos-unstable {
          inherit system;
          overlays = nixpkgs.lib.attrValues self.overlays;
        };
        pkgs = inputs.nixpkgs.legacyPackages.${system};
        pkgs_unstable = inputs.nixos-unstable.legacyPackages.${system};
        treefmtEval = treefmt-nix.lib.evalModule pkgs_unstable treefmtConf;
      in
      {
        devShells.default = pkgs.mkShell { buildInputs = [ ]; };
        formatter = treefmtEval.config.build.wrapper;
        checks.formatting = treefmtEval.config.build.check self;
        # expose nixpkgs with overlay; TODO: figure out role of config
        #legacyPackages = nixpkgs;

        # inspired by https://github.com/Mic92/dotfiles/blob/main/home-manager/flake-module.nix
        # run like: `nix run .#hm -- <action>`
        apps.hm = {
          type = "app";
          program = "${pkgs.writeShellScriptBin "hm" ''
                set -x
                export PATH=${
                  pkgs.lib.makeBinPath [
                    pkgs.git
                    pkgs.coreutils
                    pkgs.findutils
                    pkgs.nix
                    pkgs.jq
                    pkgs.unixtools.hostname
                  ]
                }
            declare -A profiles=(
              ["framenix"]="spiollinux-desktop"
              ["thinknix"]="spiollinux-desktop"
              ["OS MacBook Pro"]="os-workmac"
            )
            user=$(id -un)
            host=$(hostname)
            if [[ -n ''${profiles["$host-$user"]} ]]; then
              profile=''${profiles["$host-$user"]};
            elif [[ -n ''${profiles[$host]:-} ]]; then
              profile=''${profiles[$host]}
            else
                echo "No suitable profile found." >2
                exit 2
            fi
            if [[ "''${1:-}" == profile ]]; then
              echo $profile
              exit 0
            fi
            ${
              inputs.home-manager.packages.${pkgs.system}.home-manager
            }/bin/home-manager --flake "${self}#$profile" "$@"
          ''}/bin/hm";
        };
      }
    );
}