-module(bt_erl_parser).
-include("bt_nodes.hrl").
-export([
  parse/2,
  parse/3
]).

%% root.
%% tree can either be TreeModule, or a 3 tuple {BBKeys, Params, GetTreeFn}.
-spec parse(TreeModuleOr3Tuple :: atom() | {list(), list(), function()}, ArgsAsProplist :: list()) -> {Node :: bt_node(), NewBB :: blackboard()}.
parse(TreeModule, ArgsAsProplist) when is_atom(TreeModule), is_list(ArgsAsProplist) ->
  parse({TreeModule:get_bb_keys(), TreeModule:get_params(), fun TreeModule:get_tree/2}, ArgsAsProplist);
parse(Tree = {_BBKeys, _Params, _GetTreeFn}, ArgsAsProplist) ->
  parse({Tree, maps:from_list(ArgsAsProplist)}, bt_parser_utils:get_namespace(), bt_blackboard:get_empty()).

%% TODO: should probably call above fn parse_root so as to not confuse with this one. since this one is anyway internal only
%% sequence
-spec parse(Node :: bt_node() | {TreeModule :: atom(), Args :: map()}, Namespace :: namespace(), BB :: blackboard()) -> {Node :: bt_node(), NewBB :: blackboard()}.
parse(Sequence, Namespace, BB) when is_record(Sequence, sequence) ->
  erl_parse_sequence:parse(Sequence, Namespace, BB);
%% selector (TODO)
parse(Selector, Namespace, BB) when is_record(Selector, selector) ->
  erl_parse_selector:parse(Selector, Namespace, BB);
%% decorator
parse(Decorator = #decorator{child = Child}, Namespace, BB) when is_record(Decorator, decorator) ->
  {NewChild, NewBB} = parse(Child, Namespace, BB),
  {Decorator#decorator{child = NewChild}, NewBB};
%% task
parse(Task, Namespace, BB) when is_record(Task, task) ->
  erl_parse_task:parse(Task, Namespace, BB);
%% if none of the above, then its a subtree
parse({{UnresolvedKeys, Params, GetTreeFn}, Args}, Namespace, BB) ->
  NewBB = bt_parser_utils:get_blackboard(UnresolvedKeys, Namespace, BB),
  bt_parser_utils:throw_error_if_args_and_params_dont_match("UnknownTree", Args, Params),
  BBKeyMap = bt_parser_utils:get_unresolved_key_bb_map(UnresolvedKeys, Namespace),
  parse(GetTreeFn(Args, BBKeyMap), Namespace, NewBB).