{ lib }:
with lib; rec {
  # TODO: refactor with mkOptionType
  mkSecretOption = { description ? "", default ? { }, allowNull ? true }:
    mkOption {
      inherit description;
      type = (
        if allowNull
        then types.nullOr
        else id
      ) (types.submodule {
        options = {
          name = mkOption ({
            description = "Name of the secret where secret is stored";
            type = types.str;
            default = default.name;
          } // (optionalAttrs (default ? "name") {
            default = default.name;
          }));

          key = mkOption ({
            description = "Name of the key where secret is stored";
            type = types.str;
          } // (optionalAttrs (default ? "key") {
            default = default.key;
          }));
        };
      });
      default = if default == null then null else { };
    };

  secretToEnv = value: {
    valueFrom.secretKeyRef = {
      inherit (value) name key;
    };
  };

  # Creates kubernetes list from a list of kubernetes objects
  mkList = { items, labels ? { } }: {
    kind = "List";
    apiVersion = "v1";

    inherit items labels;
  };

  # Creates hashed kubernetes list from a list of kubernetes objects
  mkHashedList = { items, labels ? { } }:
    let
      hash = builtins.hashString "sha1" (builtins.toJSON items);

      labeledItems = map
        (item:
          recursiveUpdate item {
            metadata.labels."kubenix/hash" = hash;
          })
        items;
    in
    mkList {
      items = labeledItems;
      labels = {
        "kubenix/hash" = hash;
      } // labels;
    };

  # Returns "<name>-<hash(data)>"
  mkNameHash = { name, data, length ? 10 }:
    "${name}-${builtins.substring 0 length (builtins.hashString "sha1" (builtins.toJSON data))}";

  # Returns the same resources with addition of injected (or overwritten) metadata.name with hashed data
  # name of the resource in Nix does not change for reference reasons
  # useful for the ConfigMap and Secret resources
  injectHashedNames = attrs:
    lib.mapAttrs
      (name: o:
        recursiveUpdate o {
          metadata.name = mkNameHash { inherit name; data = o.data; };
        }
      )
      attrs;


  inherit (lib) toBase64;
  inherit (lib) octalToDecimal;
}