-module(bt_helper).
-include("bt_nodes.hrl").

-export([
  make_task/3,
  make_decorator/3,
  make_erl_tree/2,
  decorate/2
]).


make_task(Module, Args, Name) ->
  #task{
    name = Name,
    module = Module,
    args = Args
  }.

%% child will be set later using bt_helper:decorate
make_decorator(Module, Args, Name) ->
  #decorator{
    name = Name,
    module = Module,
    args = Args
  }.

make_erl_tree(BtErlTree, Args) when is_record(BtErlTree, bt_erl_tree) ->
  BtErlTree#bt_erl_tree{args = Args}.

%% single decorator passed
decorate(Node, Decorator) when is_record(Decorator, decorator) ->
  decorate_internal(Node, [Decorator]);
%% reverse list since more intuitive to specify higher decorator before lower decorator
decorate(Node, DecoratorList) when is_list(DecoratorList) ->
  decorate_internal(Node, lists:reverse(DecoratorList)).

decorate_internal(Node, []) ->
  Node;
decorate_internal(Node, [Decorator | RestOfDecorators]) when is_record(Decorator, decorator) ->
  DecoratedOnce = Decorator#decorator{
    child = Node
  },
  decorate_internal(DecoratedOnce, RestOfDecorators).