erlang_behaviour_trees

%% record definitions for nodes

%% TODO: should probably prefix everything with bt_ eg. bt_decorator
-record(decorator, {
  name :: string(),
  module :: atom(),
  args :: map(),
  state :: term(),
  child :: bt_erl_node(),
  metadata :: bt_metadata()
}).

-record(sequence, {
  name :: string(),
  namespace :: namespace(),
  children :: list(bt_erl_node()),
  metadata :: bt_metadata()
}).

%% TODO: add selector
-record(selector, {
  name :: string(),
  namespace :: namespace(),
  children :: list(bt_erl_node()),
  metadata :: bt_metadata()
}).

-record(task, {
  name :: string(),
  module :: atom(),
  args :: map(),
  state :: term(),
  metadata :: bt_metadata()
}).

%% an intermediate representation of a node generator
%% this is used when defining an erlang based tree
%% this should NOT be present in parsed behaviour tree!
-record(bt_erl_tree, {
  bb_keys = [] :: list(string()),
  params = [] :: list(string()),
  generator :: function(), %% arity 2: bb_keys, params as dictionaries
  %% args will not be filled during definition! only when it is instantiated
  %% should ideally have two different records for definition/instantiation?
  args = #{} :: map()
}).

-record (bt_metadata, {
  status=not_run :: bt_status() | not_run,
  %% these are all optional right now, not filling them since not using them.
  prev_state :: term(),
  prev_bb :: blackboard() | undefined,
  next_bb :: blackboard() | undefined
}).

-type namespace() :: list(string()) | undefined.
-type decorator() :: #decorator{}. 
-type sequence() :: #sequence{}.
-type selector() :: #selector{}.
-type task() :: #task{}.
-type bt_erl_tree() :: #bt_erl_tree{}.
-type blackboard() :: map().
-type bt_event() :: term().
-type bt_status() :: success | failure | running.
-type bt_metadata() :: #bt_metadata{} | undefined.
-type bt_node() :: decorator() | sequence() | selector() | task().
-type bt_erl_node() :: bt_node() | bt_erl_tree().