{ config, lib, ... }:
let
  inherit (lib)
    mkOption
    types
    ;
  cfg = config;
in
{
  options.assets = mkOption {
    description = ''
      Collection of assets, i.e. static files that can be linked to from within documents
    '';
    type = with types; attrsOf (submodule ({ config, ... }: {
      imports = [ cfg.content-types.document ];
      options.path = mkOption {
        type = types.path;
      };
      config.outputs."" = if lib.isStorePath config.path then config.path else "${config.path}";
    }));
    default = { };
  };

  config.files = with lib;
    let
      flatten = attrs: mapAttrsToList
        (name: value:
          # HACK: we somehow have to distinguish a module value from regular attributes.
          #       arbitrary choice: the outputs attribute
          if value ? outputs then value else mapAttrsToList value)
        attrs;
    in
    cfg.templates.files (flatten cfg.assets);
}