{
  config,
  lib,
  pkgs,
  ...
}:
let
  cfg = config.my_btrbk;
  inherit (lib) mkEnableOption mkIf mkOption;
  types = lib.types;
in
{
  options.my_btrbk = {
    enable = mkEnableOption "Btrbk backups";
    sshKeyFile = mkOption {
      type = types.nonEmptyStr;
    };
    sshUser = mkOption {
      type = types.nonEmptyStr;
      default = "btrbk";
    };
  };

  config = mkIf cfg.enable {
    services.btrbk.instances."remote_falcon" = {
      onCalendar = "daily";
      settings = {
        ssh_identity = cfg.sshKeyFile;
        ssh_user = cfg.sshUser;

        incremental = "yes";
        stream_compress = "zstd";
        stream_compress_level = "3";
        target_preserve_min = "no";
        target_preserve = "5d 4w 6m";

        subvolume = {
          "/" = {
            snapshot_name = "root";
          };
          "/home" = {
            snapshot_name = "home";
          };
        };
        snapshot_dir = "/.btrbk_snapshots";
        target = "send-receive ssh://10.0.0.5/zpool-backup/backups/${config.networking.hostName}";
      };
    };
  };
}