:- module(agent, [init, look/0, move/1, take/1]).


:- consult('parser.prolog').
:- consult('map.prolog').




% initialisation

init :-
    initPos,
    initPits,
    initWumpus,
    initGold,
    initBats, !.


initPos :-
    roomList(R),
    random_member(X,R),
    retractall(here(_)),
    not(somethingAt(X)),
    asserta(here(X)).


initPits :- true.


initWumpus :-
    roomList(R),
    random_member(X,R),
    retractall(wumpusAt(_)),
    not(somethingAt(X)),
    asserta(wumpusAt(X)).


initGold :- true.


initBats :- true.




% command functions

look :-
    here(L),
    writeSenses(L),
    writeExits(L).


move(D) :-
    here(L),
    connects(L,N,D),
    retract(here(L)),
    asserta(here(N)),
    join(['You move to the ',D,' .\n\n'],M),
    write(M), !.


take(T) :-
    here(L),
    itemAt(T,L),
    canTake(T),
    retract(itemAt(T,L)),
    asserta(holding(T)),
    write('Taken.\n\n'), !.




% letting the player know what's going on

writeSenses(L) :-
    glitter(L),
    breeze(L),
    bats(L),
    stench(L).


glitter(_) :- not(current_predicate(goldAt/1)).
glitter(L) :-
    goldAt(L),
    write('You see a glitter along the sandy floor of the cave.\n').


breeze(_) :- not(current_predicate(pitAt/1)).
breeze(L) :-
    connects(L,X,_),
    pitAt(X),
    write('A cold breeze blows through the room, making you shiver slightly.\n').


bats(_) :- not(current_predicate(batsAt/1)).
bats(L) :-
    connects(L,X,_),
    batsAt(X),
    write('All available surfaces are covered in guano. How unsanitary.\n').


stench(_) :- not(current_predicate(wumpusAt/1)).
stench(L) :-
    connects(L,X,_),
    wumpusAt(X),
    write('An overpowering stench fills your nose.\n').


writeExits(L) :-
    findall(X, connects(L,_,X), E),
    intercalate(E, ', ', O),
    join(['There are exits to the ',O,'.\n'],W),
    write(W).




% miscellaneous clauses

somethingAt(X) :- current_predicate(here/1), here(X).
somethingAt(X) :- current_predicate(wumpusAt/1), wumpusAt(X).
somethingAt(X) :- current_predicate(pitAt/1), pitAt(X).
somethingAt(X) :- current_predicate(goldAt/1), goldAt(X).
somethingAt(X) :- current_predicate(batsAt/1), batsAt(X).


intercalate(I,S,O) :- O is I.