nixfiles-emily/modules/machine-type/default.nix

{ config, lib, ...}: with lib;
let
  cfg = config.kyouma.machine-type; 
in {
  options.kyouma.machine-type = {
    physical = mkOption {
      type = types.bool;
      default = false;
      description = mdDoc "Mark machine as physical.";
    };
    
    virtual = mkOption {
      type = types.bool;
      default = false;
      description = mdDoc "Mark machine as virtual.";
    };

    router = mkOption {
      type = types.bool;
      default = false;
      description = mdDoc "Mark machine as router.";
    };
    
    headless = mkOption {
      type = types.bool;
      default = false;
      description = mdDoc "Mark machine as headless.";
    };

    graphical = mkOption {
      type = types.bool;
      default = false;
      description = mdDoc "Mark machine as graphical.";
    };

    portable = mkOption {
      type = types.bool;
      default = false;
      description = mdDoc "Mark machine as portable.";
    };
  };
  config = {
    assertions = [
      { assertion = !(cfg.physical && cfg.virtual);
        message = "machine-type.physical and machine-type.virtual are mutually exclusive";
      }
      { assertion = !(cfg.headless && cfg.graphical);
        message = "machine-type.headless and machine-type.graphical are mutually exclusive";
      }
      { assertion = if cfg.router then cfg.headless == cfg.router else true; 
        message = "hosts of machine-type.router must also be machine-type.headless";
      }
      { assertion = if cfg.portable then cfg.physical == cfg.portable else true;
        message = "hosts of machine-type.protable must also be machine-type.physical";
      }
    ];
  };
}