{
  pkgs ? import <nixpkgs> {}
}:

with pkgs.lib;
with import ./lib.nix { inherit pkgs; inherit (pkgs) lib; };

let
  evalKubernetesModules = configuration: evalModules rec {
    modules = [
      ./kubernetes.nix
      ./modules.nix configuration
    ];
    args = {
      inherit pkgs;
      name = "default";
      k8s = import ./k8s.nix {
        inherit pkgs;
        inherit (pkgs) lib;
      };
      module = null;
    };
  };

  flattenResources = resources: flatten (
    mapAttrsToList (name: resourceGroup:
      mapAttrsToList (name: resource: resource) resourceGroup
    ) resources
  );

  filterResources = resourceFilter: resources:
    mapAttrs (groupName: resources:
      (filterAttrs (name: resource:
        resourceFilter groupName name resource
      ) resources)
    ) resources;

  toKubernetesList = resources: {
    kind = "List";
    apiVersion = "v1";
    items = resources;
  };

  removeNixOptions = resources:
    map (filterAttrs (name: attr: name != "nix")) resources;

  buildResources = {
    configuration ? {},
    resourceFilter ? groupName: name: resource: true,
    withDependencies ? true,
    writeJSON ? true
  }: let
    evaldConfiguration = evalKubernetesModules configuration;

    allResources = moduleToAttrs (
      evaldConfiguration.config.kubernetes.resources //
      evaldConfiguration.config.kubernetes.customResources
    );

    filteredResources = filterResources resourceFilter allResources;

    allDependencies = flatten (
      mapAttrsToList (groupName: resources:
        mapAttrsToList (name: resource: resource.nix.dependencies) resources
      ) filteredResources
    );

    resourceDependencies =
      filterResources (groupName: name: resource:
        elem "${groupName}/${name}" allDependencies
      ) allResources;

    finalResources =
      if withDependencies
      then recursiveUpdate resourceDependencies filteredResources
      else filteredResources;

    resources = unique (removeNixOptions (
      # custom resource definitions have to be allways created first
      (flattenResources (filterResources (groupName: name: resource:
        groupName == "customResourceDefinitions"
      ) finalResources)) ++

      # everything but custom resource definitions
      (flattenResources (filterResources (groupName: name: resource:
        groupName != "customResourceDefinitions"
      ) finalResources))
    ));

    kubernetesList = toKubernetesList resources;

    listHash = builtins.hashString "sha1" (builtins.toJSON kubernetesList);

    hashedList = kubernetesList // {
      labels."kubenix/build" = listHash;
      items = map (resource: recursiveUpdate resource {
        metadata.labels."kubenix/build" = listHash;
      }) kubernetesList.items;
    };

    result = if writeJSON then
      pkgs.writeText "resources.json" (builtins.toJSON hashedList)
      else hashedList;
  in
    result;

  buildTest = test: version: buildResources {
    configuration = {
      require = [test {
        config.kubernetes.version = version;
      }];
    };
  };

in {
  inherit buildResources;

  tests."k8s-1_7" = buildTest ./test/default.nix "1.7";
  tests."k8s-1_8" = buildTest ./test/default.nix "1.8";
  tests."k8s-1_9" = buildTest ./test/default.nix "1.9";
  tests."k8s-1_10" = buildTest ./test/default.nix "1.10";
  tests."k8s-1_11" = buildTest ./test/default.nix "1.11";
}