nichts/modules/services/greetd.mod.nix

{
  config,
  lib,
  pkgs,
  ...
}:
let
  inherit (lib.meta) getExe getExe';
  inherit (lib.modules) mkIf;
  inherit (lib.options) mkOption mkEnableOption;
  inherit (lib.types) str listOf;

  inherit (config.meta.mainUser) username;
  cfg = config.modules.services.greetd;
in
{
  options.modules.services.greetd = {
    enable = mkEnableOption "greetd";
    greeter = mkOption {
      description = "greetd frontend to use";
      type = str;
    };
    launchOptions = mkOption {
      description = "/etc/greetd/environments as list of strings";
      type = listOf str;
    };
    session = mkOption {
      description = "Which login session to start";
      type = str;
      default = "niri";
    };
  };

  config = mkIf cfg.enable {
    services.greetd =
      let
        session = {
          command = ''
            ${getExe pkgs.greetd.tuigreet} \
              -c \"${cfg.session}\" \
              -r
              -t --time-format "DD.MM.YYYY"
              --asteriks'';
          user = "greeter";
        };
      in
      {
        enable = true;
        vt = 7;
        settings = {
          default_session = session;
          initial_session = session;
        };
      };
  };
}