{ nglib, nixpkgs }:
nglib.makeSystem {
  system = "x86_64-linux";
  name = "ra-systems-getmail";
  inherit nixpkgs;
  config = ({ pkgs, config, nglib, lib, ... }:
    {
      config = {
        dumb-init = {
          enable = true;
          type.services = {};
        };

        users.users."vmail" = {
          uid = config.ids.uids.vmail;
          description = "vmail user.";
          group = "vmail";
          shell = "${pkgs.bash}/bin/bash";
        };
        users.groups."vmail" = {
          gid = config.ids.gids.vmail;
        };

        init.services.getmail =
          let
            courier-unicode = with pkgs;
              stdenv.mkDerivation rec {
                name = "courier-unicode";
                version = "2.2.3";

                src = pkgs.fetchurl {
                  url = "mirror://sourceforge/courier/courier-unicode/${version}/${name}-${version}.tar.bz2";
                  sha256 = "sha256-COz13JdSnOOqncqghYYHYt5jbr75aL9LbgzfqvGMev8=";
                };

                nativeBuildInputs = [ perl ];
              };
            maildrop-fixed = pkgs.maildrop.overrideAttrs (
              old:
              { patches =
                  [ ./dont-reset-path.patch
                    ./maildrop.configure.hack.patch
                  ];
                version = "3.0.7";
                src = pkgs.fetchurl {
                  url = "mirror://sourceforge/courier/maildrop/3.0.7/maildrop-3.0.7.tar.bz2";
                  sha256 = "sha256-YFzoHDk5BEcy2uRyQhlTTl27UVyAdgvjYRkUq1wfeCU=";
                };
                nativeBuildInputs = with pkgs; [ pcre2 pkg-config ];
                buildInputs = with pkgs; [ libidn courier-unicode ];
              });

            getmail6-fixed = pkgs.getmail6.overrideAttrs (
              old:
              { patches =
                  [ ./getmail-read-exec-from-path.patch
                  ];
              }
            );
          in
          {
            shutdownOnExit = true;
            script = pkgs.writeShellScript "getmail-run"
              ''
                export PATH=${with pkgs; lib.makeBinPath [ busybox runit bash getmail6-fixed maildrop-fixed ]}:${pkgs.opensmtpd}/libexec/opensmtpd:$PATH

                chown vmail:vmail -R /getmail.d

                set -m

                for rcfile in /getmail.d/getmail.*.rc
                do
                  foo="$(basename "''${rcfile}")"
                  bar="''${foo#"getmail."}"
                  email="''${bar%".rc"}"

                  mkdir -p "/getmail.d/''${email}"
                  chown vmail:vmail -R "/getmail.d/''${email}"

                  (
                    while true
                    do
                      chpst -u vmail:vmail getmail -i INBOX -n -r "/getmail.d/getmail.''${email}.rc" --getmaildir "/getmail.d/''${email}"
                      sleep 10
                    done
                  ) &
                done

                wait
              '';
            enabled = true;
          };
      };
    });
  }

  # /usr/lib/sendmail -i -oem -f %F %T