{
  config,
  lib,
  ...
}: let
  cfg = config.soispha.services.snapper;
in {
  options.soispha.services.snapper = {
    enable = lib.mkEnableOption "snapper config";
  };

  config = lib.mkIf cfg.enable {
    services.snapper = {
      configs = {
        srv = {
          SUBVOLUME = "/srv";
          FSTYPE = "btrfs";
          # users and groups allowed to work with config
          ALLOW_GROUPS = ["wheel"];

          # sync users and groups from ALLOW_USERS and ALLOW_GROUPS to .snapshots
          # directory
          SYNC_ACL = true;

          # run daily number cleanup
          NUMBER_CLEANUP = false;

          # limit for number cleanup
          NUMBER_MIN_AGE = "1800";
          NUMBER_LIMIT = "50";
          NUMBER_LIMIT_IMPORTANT = "10";

          # create hourly snapshots
          TIMELINE_CREATE = true;

          # cleanup hourly snapshots after some time
          TIMELINE_CLEANUP = true;

          # limits for timeline cleanup
          TIMELINE_MIN_AGE = "1800";
          TIMELINE_LIMIT_HOURLY = "7";
          TIMELINE_LIMIT_DAILY = "3";
          TIMELINE_LIMIT_WEEKLY = "2";
          TIMELINE_LIMIT_MONTHLY = "0";
          TIMELINE_LIMIT_YEARLY = "2";

          # cleanup empty pre-post-pairs
          EMPTY_PRE_POST_CLEANUP = true;
        };
      };
    };
  };
}