nixos/postgresql: Remove toplevel `with lib;`

{ config, lib, pkgs, ... }:

with lib;

let

  inherit (lib)

    attrValues

    concatMapStrings

    concatStringsSep

    const

    elem

    filterAttrs

    isString

    literalExpression

    mapAttrs

    mapAttrsToList

    mkAfter

    mkBefore

    mkDefault

    mkEnableOption

    mkIf

    mkMerge

    mkOption

    mkPackageOption

    mkRemovedOptionModule

    mkRenamedOptionModule

    optionalString

    types

    versionAtLeast

    ;

  cfg = config.services.postgresql;

    if true == value then "yes"

    else if false == value then "no"

    else if isString value then "'${lib.replaceStrings ["'"] ["''"] value}'"

    else toString value;

    else builtins.toString value;

  # The main PostgreSQL configuration file.

  configFile = pkgs.writeTextDir "postgresql.conf" (concatStringsSep "\n" (mapAttrsToList (n: v: "${n} = ${toStr v}") (filterAttrs (const (x: x != null)) cfg.settings)));

  config = mkIf cfg.enable {

    assertions = map ({ name, ensureDBOwnership, ... }: {

      assertion = ensureDBOwnership -> builtins.elem name cfg.ensureDatabases;

      assertion = ensureDBOwnership -> elem name cfg.ensureDatabases;

      message = ''

        For each database user defined with `services.postgresql.ensureUsers` and

        `ensureDBOwnership = true;`, a database with the same name must be defined

        # Wait for PostgreSQL to be ready to accept connections.

        postStart =

          ''

            PSQL="psql --port=${toString cfg.settings.port}"

            PSQL="psql --port=${builtins.toString cfg.settings.port}"

            while ! $PSQL -d postgres -c "" 2> /dev/null; do

                if ! kill -0 "$MAINPID"; then exit 1; fi