{
  description = "Zone File Generator";
  inputs.dns.url = "github:nix-community/dns.nix";
  outputs =
    { dns, ... }:
    let
      email = "admin@satr14.my.id";
      domains."0" = {
        domain = "part-of.my.id";
        nameservers = [
          "adele.ns.cloudflare.com"
          "fattouche.ns.cloudflare.com"
        ];
      };
      inherit (import <nixpkgs> { }) lib;
      domainsFolder = builtins.readDir ./domains;
      domainFiles = lib.filterAttrs (
        name: type: type == "regular" && builtins.match ".*\\.nix" name != null
      ) domainsFolder;
      subdomains = lib.mapAttrs' (
        name: _:
        let
          key = builtins.replaceStrings [ ".nix" ] [ "" ] name;
        in
        {
          name = key;
          value = import (./domains + "/${name}") { inherit dns; };
        }
      ) domainFiles;
    in
    {
      packages.x86_64-linux = builtins.mapAttrs (
        _: domain:
        dns.util.x86_64-linux.writeZone domain.domain (
          with dns.lib.combinators;
          {
            SOA = {
              adminEmail = email;
              nameServer = builtins.head domain.nameservers;
              serial = builtins.currentTime;
            };
            NS = domain.nameservers;
            # note: Cloudflare ignores SOA and NS records uploaded via Zone File, they are included just so that dns.nix builds a valid zone file.
            inherit subdomains;
          }
        )
      ) domains;
    };
}