{ pkgs }:
let
  inherit (pkgs) lib;
in
{
  mkWrapper =
    {
      config,
      name,
      enableTui ? false,
      modules ? [ ],
    }:
    let
      merged_config = lib.foldl' (acc: elem: acc // elem.config) config modules;
      checks = lib.concatStringsSep "\n" (
        lib.concatMap (
          attrs:
          lib.mapAttrsToList (k: v: ''
            echo "Running ${k}"
            ${v}
            echo "Passed ${k}"
          '') attrs.checks
        ) modules
      );
      removeNullAndEmptyAttrs =
        attrs:
        let
          f = lib.filterAttrsRecursive (key: value: value != null && value != { });
        in
        # filterAttrsRecursive doesn't delete the *resulting* empty attrs, so we must
        # evaluate it again and to get rid of it.
        lib.pipe attrs [
          f
          f
        ];
      toPCJson =
        name: attrs:
        pkgs.writeTextFile {
          name = "process-compose-${name}.json";
          text = builtins.toJSON attrs;
        };
      configFile = toPCJson name (
        removeNullAndEmptyAttrs (
          merged_config
          // {
            is_tui_disabled = !enableTui;
          }
        )
      );
    in
    pkgs.writeShellApplication {
      inherit name;
      text = ''
        ${checks}
         PC_CONFIG_FILES=${configFile} ${pkgs.process-compose}/bin/process-compose "$@"

      '';
    };
  mkPostgres =
    {
      name,
      default_config ? true,
      config ? { },
      extra_config ? '''',
      package ? pkgs.postgresql,
      ...
    }:
    let
      merged_config =
        (
          if default_config then
            {
              listen_addresses = "localhost";
              port = 5432;
              shared_buffers = "128MB";
              worker_mem = "4M";
              logging_collector = "off";

            }
          else
            { }
        )
        // config;
      toStr =
        value:
        if true == value then
          "yes"
        else if false == value then
          "no"
        else if lib.isString value then
          "'${lib.replaceStrings [ "'" ] [ "''" value ]}'"
        else
          builtins.toString value;
      configFile = pkgs.writeTextDir "postgresql.conf" (
        lib.concatStringSep "\n" (
          lib.mapAttrsToList (n: v: "${n} = ${toStr v}") (lib.filterAttrs (
            lib.const (x: x != null)
          )) merged_config
        )
      );
      configFileCheck = pkgs.writeShellScript {
        name = "postgresql-config-check-${name}";
        text = ''
          ${package}/bin/postgres -D${configFile} -C config_file
          touch $out
        '';
      };
    in
    {
      config.processes."${name}" = {
      };
      checks."postgresql${name}" = configFileCheck;
    };
}