% $Id: agent.pl,v 1.2 2006/11/12 19:43:31 ioerger Exp $

:- ensure_loaded(wumpus). % load wumpus.pl

:- dynamic action/2,holding/1.

my_reset :-
  retractall(action(_,_)),
  retractall(holding(_)),
  reset.

go(0).
go(N) :- 
  decide(Action),
  format("~ndoing: ~w~n",[Action]),
  my_do(Action),
  M is N-1,
  go(M).

my_do(Action) :-
  now(X),
  remember_holding_gold(Action),
  assert(action(Action,X)),
  do(Action).

decide(pickup(gold)) :- glitter,\+ holding(gold).
decide(A) :- pick_random_action(A).

actions([forward,turn(left),turn(right)]).

pick_random_action(Action) :- 
  actions(Actions),
  length(Actions,L),
  X is random(L),
  Y is X+1,
  nth(Actions,Y,Action).

remember_holding_gold(pickup(gold)) :-
  glitter,
  assert(holding(gold)),!.
remember_holding_gold(_). % succeed trivially in all other cases