{ self, inputs, lib, pkgs, ... } @ args:

with lib;
with lib.my;
{
  mkSystem = { hostPath, nixpkgs ? inputs.unstable, system ? "x86_64-linux", overlays ? null, extraModules ? null }:
    nixpkgs.lib.nixosSystem (
      {
        system = system;

        specialArgs = args;

        modules = [
          {
            networking.hostName = mkDefault (removeSuffix ".nix" (baseNameOf hostPath));
            nix.flakes.enable = true;
            system.configurationRevision = self.rev or "dirty";
            documentation.man = { enable = true; generateCaches = true; };
          }
          (import hostPath)
        ] ++ mapModulesRec' ../modules import
        ++ nixpkgs.lib.optional (overlays != null) { nixpkgs.overlays = overlays; }
        ++ nixpkgs.lib.optionals (extraModules != null) extraModules;

        # let deployment options to be set without breaking eval on nixosConfigurations
        extraModules = [ inputs.colmena.nixosModules.deploymentOptions ];
      }
    );

  mapSystems = dir: attrs @ { system ? system, ... }:
    mapModules dir
      (hostPath: mkSystem { inherit hostPath; });

  mkColmenaFromNixOSConfigurations = conf:
    {
      meta = {
        # Colmena requirement. Will be overridden in nodeNixpkgs.
        nixpkgs = import inputs.unstable { system = "x86_64-linux"; };
        nodeNixpkgs = builtins.mapAttrs (_: value: value.pkgs) conf;
        nodeSpecialArgs = builtins.mapAttrs (_: value: value._module.specialArgs) conf;
      };
    } // builtins.mapAttrs (_: value: { imports = value._module.args.modules; }) conf;

  mkHydraFromNixOSConfigurations = conf:
    mapAttrs' (name: value: { name = "nixos-${name}"; value = value.config.system.build.toplevel; }) conf;
}